Project code - Statistics
The table below shows the project code of the public data and the related number of fits files.
| # | Project code | #of FITS files | Title | Abstract | Scientific keyword | Category | Release date |
|---|---|---|---|---|---|---|---|
| 1 | 2015.1.01005.S | 9 | JET-ISM interactions in a radio-loud merging galaxy at the initial AGN feedback stage | Feedback from active galactic nuclei (AGNs) has been recognized as an important process in the evolution of galaxies. One type of AGN feedback takes the form of interactions of jets induced by AGN activity with the ISM. From numerical simulations, it has been predicted that cold molecular gas in the ISM that are affected by jets may be compressed by the high pressure, dissociated by shocks, or driven out of a host galaxy by outflows. However it is still not clear how jet-ISM interactions affect on cold molecular gas. From our previous study using ALMA Band3 data, we discovered a large warped disk of molecular gas and small-scale (4 kpc) radio lobes in a merging galaxy, Arp 187. It is quite intriguing, because the kinematic age of the radio-jets is quite young (0.06 Myr). Arp 187 is the clearest case of on-going jet-ISM interactions apparently buried within the rich-ISM of the host galaxy. We thus propose to image Arp 187 in the dense gas tracers in Band 7 and the continuum emission at Band 3 and Band 4 in order to characterize the young radio jets, estimating the spatially-resolved spectral ages, and look for signatures of cold molecular gas shocked/compressed by the jets. | Merging and interacting galaxies, Outflows, jets, feedback | Galaxy evolution | 2018-10-03T14:05:19.000 |
| 2 | 2019.2.00027.S | 21 | A Pilot Study of Warm Molecular Gas in High-redshift Obscured Quasars | We request ACA observations of the CO(J=7-6) transition in a small sample of 5 high-redshift (z>~3), hyper-luminous (Lbol > 10^14 Lsun), dust-obscured quasars for which at least two other lower-J CO line transitions have already been detected with ALMA and VLA. This is a pilot program motivated by the surprisingly bright detection of the CO(J=12-11) transition in the most luminous obscured quasar known, W2246-0526, which suggests that it is possible to detect mid-J CO transitions in these extreme objects using the ACA. The goal of this project is two-fold: (1) to start investigating the excitation properties of the warm molecular gas in high-z obscured quasars and place them in context with other dusty galaxy populations, and (2) to determine whether the CO(J=7-6) line, which has recently been proposed as a good star formation rate indicator, can be truly used in galaxies with such extreme environments. This will be the first time that such a study is conducted in this new population of high-z quasars. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2022-10-28T04:31:47.000 |
| 3 | 2017.1.00471.S | 78 | Gas kinematics of galaxies infalling into a massive galaxy cluster at z=1.46 | We propose spatially resolved measurement of CO J=2-1 emission lines and dust continuum emissions to investigate gas kinematics of galaxies associated with a X-ray massive galaxy cluster at z=1.46. In the cycle 3 observations at a lower resolution, we have detected CO J=2-1 emission lines from 17 cluster member galaxies, whose phase space implies that they are likely to be infalling into a potential of the galaxy cluster and thus spend a small amount of time after arriving near the cluster center. The CO velocity maps allow us to discuss a contribution of merger to evolution of cluster galaxies and a difference of kinematics between the high-z progenitors of present-day slow/fast rotators and field galaxies gives us an insight on pre-processing and post-processing responsible for evolution of cluster galaxies. We also derive dynamical masses from the line profiles, which enables an independent measurement of gas fraction of galaxies by comparing with stellar masses. Star formation efficiency of the galaxies and comparison of sizes between CO gas and stellar component also allow us to discuss the evolution of galaxy structures such as bulge and disk. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2019-03-27T18:02:39.000 |
| 4 | 2018.1.01010.S | 5 | Connecting formation & multiplicity: high-resolution imaging of a fragmenting disc around a massive young star | It is unclear how massive stars attain their high masses, and the connection between massive star formation and the high multiplicity of OB stars is not well characterised. Furthering our understanding requires high angular resolution observations of the circum(proto)stellar environments of young massive stars. Here we propose to observe the innermost regions of the young massive star G11.92-0.61 MM 1, a >20 solar mass star surrounded by a Keplerian disc which is undergoing gravitational fragmentation. Our proposed settings will allow imaging in both continuum and molecular lines down to the expected scales of the HCHII region, enabling us to search for evidence of further fragmentation and substructure within the circumstellar disc. Our spectral tuning contains key transitions of CH3CN ladders, which we will model with radiation transfer codes in order to determine the physical conditions of the gas in the disc. Our observations will provide some of the highest resolution observations of the innermost regions of a forming massive young stellar object, and allow us investigate in detail how massive star formation and stellar multiplicity are linked. | High-mass star formation, Astrochemistry | ISM and star formation | 2022-09-09T15:42:36.000 |
| 5 | 2019.1.01635.S | 40 | Comprehensive study of the physical conditions of the molecular gas in the inner 5-7 kpc of two star-forming galaxies | CO emission lines are commonly used to derive molecular mass estimates for local and high redshift galaxies. Yet our understanding on how the excitation of these lines varies with local physical conditions is still quite limited. Comprehensive datasets providing access to several physical parameters (e.g. metallicity, electron density, extinction, radiation field, SFR, shocks) that affect the molecular gas excitation need to be combine with multi-line, multi-transition observations sampling large regions in galaxies to make significant progress. We propose ~250pc resolution, sensitive [CI](1-0) and CO(4-3) mapping with the ACA of the inner ~6 kpc region of two local star-forming galaxies from the PHANGS ALMA+MUSE+HST surveys to assemble such a dataset. Combined with existing ALMA CO(1-0), CO(2-1) and CO(3-2) imaging, we will probe the excitation conditions for CO and the alternative molecular gas mass tracer [CI] across the different physical environments present in these regions quantifying the impact of, e.g., radiation field and metallicity on the excitation of the CO and [CI] lines which is not well understood and on the CO-/[CI]-to-H_2 conversion factors. | Spiral galaxies | Local Universe | 2022-10-23T15:35:02.000 |
| 6 | 2012.1.00075.S | 8 | SN1987A: A Unique Laboratory of Shock, Molecular and Dust Physics | Supernovae are critical engines driving the evolution of interstellar gas in galaxies: the dominant source of mechanical and chemical feedback from star formation, an important source of dust creation, and the origin of energetic particles. Supernova SN1987A is the brightest and nearest supernova observed since Kepler's SN1604 and there are important outstanding questions about shock physics and the production of dust in supernovae that only ALMA can answer. Exciting new scientific opportunities available to Cycle 1 ALMA include: confirmation of the remarkably high dust mass produced in the ejecta, verification of CO emission from the ejecta, high enough spatial resolution of the nonthermal particle-accelerating ring to resolve it and separate it from the X-ray emitting shock front, studying the spatial and temporal evolution of the remnant, and searching directly for the elusive compact remnant. A wealth of scientific information is accessible with a small investment of telescope time: We propose to image the continuum in all four bands to separate and analyze dust emission from the inner debris, nonthermal emission from particles accelerated by the outer shock, and any possible thermal bremsstrahlung and compact remnant. We will additionally image broad (~2500 km/s FWHM) CO 1-0 and 2-1 emission from the central debris. | Supernovae (SN) ejecta | Stars and stellar evolution | 2015-11-04T14:22:51.000 |
| 7 | 2013.1.00021.S | 1 | NGC 4650A: the prototype Polar Ring Galaxy | Polar-ring galaxies (PRG) are a unique class of objects, tracing special episodes in the galaxy mass assembly: they can be formed through galaxy interaction and merging, but also through accretion from cosmic filaments. In addition they are highly interesting to study the dependencies of the star formation laws on surface density and metallicity, and determine 3D-shape of dark matter haloes. We propose to map in the CO(3-2) line at high resolution the polar ring of NGC4650A, the prototype of the class. The polar disk is the most recently assembled sub-system, very rich in gas and where new stars are formed. We will determine the gas distribution and the star formation efficiency, with possible thresholds. The high resolution kinematics of the molecular gas, predominant in the central parts, will precise with more accuracy the determination of the 3D-potential, already tackled through optical, near-infrared, and HI-21cm data. Through comparison with numerical models this will help to deduce the dark matter content and the halo 3D-shape. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2016-11-27T22:36:04.000 |
| 8 | 2024.1.01580.S | 0 | Core mass function in a low metallicity star-forming region in the outer Galaxy | The shape of the stellar initial mass function (IMF) and whether it is universal are important topics in modern astrophysics. The core mass function (CMF) in nearby star forming regions (<1kpc) is similar in shape to the IMF, suggesting a unified origin. Measurements of CMF in more distant regions have been made possible with ALMA, but observationally it is still largely unexplored whether a low metallicity condition will significantly affect the CMF (and low-mass IMF) shape. The formation of stars at low metallicities is a central problem in galaxy formation and evolution, i.e., to understand the properties of the high redshift universe. Here we propose to survey the dense gas/dust content and measure the CMF in Sh2-284, one of the lowest metallicity star-forming regions in the Galaxy. The proposed study will be complemented by approved HST/JWST program aiming to measure the IMF in the same region. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 9 | 2013.1.00993.S | 7 | Resolving structure and physics toward a Photodissociation Region associated with N55 in the Large Magellanic Cloud | We propose an ALMA observation of a PDR associated with the HII region N55 in the LMC. Our Spitzer observations of this region have revealed a well defined stratification in intense emission of H2 and PAH with clumps and filamentary structures. The unique edge-on viewing angle of this PDR gives us an excellent opportunity to quantify different phases of gas and dust and to test the effects of low metallicity environment on the physical and chemical properties of the PDR. We propose to use the unique observing capabilities of ALMA to map 13CO(1-0), 12CO(2-1), 13CO(2-1), CS, C2H and HCN with an angular resolution 3" which allow us to constrain temperature, density and structure of this PDR. We plan to compare these observations with a PDR model calculated for low metallicity environment. In lower metallicity environments, the penetrating FUV intensity is enhanced due to the low dust-to-gas ratio. This scenario can be tested if we can well resolve the chemistry and geometry of a carefully selected PDR in a nearby low metallicity galaxy. For this kind of studies we require high spectral and spatial resolution observation of the key PDR tracers. | Magellanic Clouds | Local Universe | 2016-05-06T12:20:13.000 |
| 10 | 2018.1.01829.S | 38 | Direct Measurement of Inner and Outer Disk Misalignment | Results from the Kepler mission suggest that exoplanetary systems are divided into two distinct populations - one with coplanar planets, and one with planets that have significant mutual inclinations (the "Kepler Dichotomy"). One explanation for this phenomenon is that dynamical processes may force planets into orbits with high mutual inclinations. These planets may interact with the disk and generate a misaligned disk structure, or vice-versa. Theory has long suggested the presence of dynamically generated disk misalignments, and recent scattered light observations with SPHERE provide indirect evidence for such systems via inner disk shadows. Recent ALMA observations show similar evidence for a misalignment in the AA Tau disk, with symmetric shadows visible in the innermost dust ring. Bright inner disk emission provides a unique opportunity to directly measure the inner and outer disk misalignment angle by observing the disk at high angular resolution and resolving its geometry. These observations will provide the first direct measurement of a disk misalignment, confirming the hypothesized phenomenon and providing a benchmark system for theoretical dynamical models. | Disks around low-mass stars | Disks and planet formation | 2020-12-05T14:23:33.000 |
| 11 | 2017.1.00696.S | 72 | Do organic molecules exist in the Large Magellanic Cloud? | It is quite likely that the precursors of life came to Earth from space, in the form of complex organic molecules carried by comets. Methanol (CH3OH) is the molecule that provides many of the building blocks for more complex species and is produced in ice mantles on grains through hydrogenation of frozen CO. Two attempts to detect complex molecules or even methanol in the Large Magellanic Cloud failed. One was conducted by us toward three YSOs with outflows, another attempt was made by Shimonishi et al. They were successful in the sense of detecting a hot core, but based on SO2, with very low upper limits on methanol. This was explained by them as due to the elevated grain temperatures in the LMC, which are produced by the high radiation field, and which would stop accretion of the building blocks of methanol, CO and H, and therefore prevent methanol production. The statistics is very low - 6 sources between Shimonishi and us. Here, we propose to observe a larger sample of 20 sources, carefully selected to be away from star forming activity, and hence with a high probability of lower dust temperature at the time of formation. | Galaxy chemistry, Dwarf/metal-poor galaxies | Galaxy evolution | 2020-01-08T18:19:35.000 |
| 12 | 2016.1.01501.S | 182 | Unbiased Chemical Survey of Protostellar Sources in Perseus | It is well known that low-mass protostellar cores show significant chemical diversity. One distinct case is hot corino chemistry characterized by rich saturated complex organic molecules, while the other distinct case is warm carbon chain chemistry (WCCC) characterized by rich carbon-chain molecules. However, the number of sources definitively classified into them are limited, and the statistics is apparently poor. We here propose to conduct an unbiased survey of chemical composition toward 37 Class 0/I protostars in the Perseus molecular cloud complex. Our recent observations toward these target sources with the single-dish telescopes shows clear chemical diversity, where many intermediate sources are found between the two distinct cases. We are going to confirm this result with ALMA to establish chemical diversity in the 100 AU scale. A relative occurrence of each category (hot corino chemistry, WCCC, or intermediate) as well as preferential association of the sources in each category with a specific part of the cloud complex will give us an important clue to understanding the origin of the chemical diversity in terms of evolutionary history and/or environmental effects. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-08-15T00:00:00.000 |
| 13 | 2019.1.01709.S | 167 | Probing the spectral evolution of jets with ALMA | We propose high-resolution continuum imaging in bands 3 and 6 of radio jets detected in the optical and/or X-rays, in order to accurately map the spectral energy distribution in the critical window between GHz radio and infrared. Our previous program on extremely powerful jets has revealed that the spectral energy distributions of these jets are more complex than previously understood, with multiple emission components of unclear origin, which are likely related to the unknown particle acceleration mechanism. This program compliments previous observations by selecting a sample with a range in morphology and extending down to low jet powers. These observations are critical to sampling the synchrotron spectrum of these resolved jets in a previously unexplored window, where our previous assumptions about the SED of resolved jets appear to be breaking down. For two targets, we request band 7 observations to confirm the completely unexpected turnover in the sub-mm spectrum which reveals that at least three distinct emission components are present in the jet. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2021-03-10T22:21:45.000 |
| 14 | 2015.1.00204.S | 23 | Search for synchrotron emission from accretion disk of black hle X-ray binary LMC X-3 | We propose to carry out band-3 and band-6 photometry of a black hole X-ray binary staying in high/soft state, in which bright radio jets are quenched. This is a unique attempt to detect the magnetic field in the black-hole accretion disks, whose existence has never been tested observationally. X-ray spectra in the high/soft state suggest that the corona of the accretion disk is composed of non-thermal electrons. Estimating the magnetic field strength using the theory of standard accretion disks, we deduce that weak synchrotron emission of the electrons can be observed in the mm-to-submm band. Thanks to the unprecedented high sensitivity, ALMA will make it possible to detect this component for the first time. The target, LMC X-3, is the most suitable to our observation, because it is the brightest black hole X-ray binary persistently observed in the high/soft state. This observation will provide direct information of a magnetic field around the inner edge of the accretion disk and give a constraint of its strength. This study will directly verify our current understanding of the physics of accretion disks. | Black holes | Stars and stellar evolution | 2017-03-25T01:38:01.000 |
| 15 | 2018.1.00520.S | 16 | Origin of the Highest Velocity Protostellar Outflow | We propose to probe the origin of the most luminous water maser source in the Galaxy, associated with a protostellar outflow that spans over 700 km/s within the W49N source G complex. This unusual outflow in the W49N starburst may signify a brief evolutionary phase of high-mass star formation that has yet to be fully characterized. Very high resolution (300 AU) is needed to separate the subcomponents of the gregarious star formation underlying the water masers. ALMA observations of a strong hydrogen recombination line (H29alpha) where the hypercompact HII regions are optically thin, together with a suite of localized, high excitation molecular lines (CH3CN, SO2, CH3OH), will resolve the ionized and molecular gas dynamics in this region. We will use these data to (1) identify the outflow source, in particular assess if it emerges from the source G hypercompact HII regions, (2) trace the outflow activity and shocks, to compare against longstanding predictions of the protostellar jet/cocoon model for the water masers, and (3) constrain the physical properties of the dense gas, to reveal in what ways this region stands out from other regions of high-mass star formation. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2021-03-06T01:05:00.000 |
| 16 | 2013.1.00524.S | 6 | ALMA Explorations of Nuclear Regions of Nearby LIRGs: Warm Molecular Gas Distribution Down to GMC Scales | We propose ALMA mapping in Band-9 at 0.12"/beam of the CO(6-5) line emission and the 450 um dust continuum in the nuclei of 4 luminous infrared galaxies (LIRGs). The data will reveal, for the first time, nuclear dense molecular gas distribution at resolutions < 50 pc, characteristic size of GMCs. Our targets include 2 starbursts and 2 AGNs, and represent two most common nuclear configurations in LIRGs: two targets with a compact nuclear core of < 1" (< 300 pc) and two with a circumnuclear disk of 2" to 2.5" in diameter (500 to 1000 pc). For the latter two targets, we also request quick ALMA observations of CO(6-5) at 0.31"/beam to recover structures over the entire nuclear disk. Our proposal expands our ALMA sample from two LIRGs observed in Cycle-0 to 4 more that represent more typical LIRGs. The ALMA results are crucial in determining physical gas/dust conditions in different nuclear configurations, spatial correlation between CO(6-5) and Pa-alpha emissions, the role AGN plays in gas heating and feedback, and if nuclear dense molecular gas remains in discrete GMCs or is compressed into spatially continuous molecular gas over scales much larger than 50 pc. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2016-10-01T00:00:00.000 |
| 17 | 2021.A.00022.S | 20 | Establishing the Golden Reference of Early Galaxy Studies at z~8-9 with [OIII]4363 detection in JWST ERO | In the last decade, ALMA has played key roles in initial FIR characterizations of early galaxies, while it raises open questions about what causes the large diversity and the difference from local galaxies. We propose ALMA [CII]158um and [OIII]88um spectroscopy for three lensed 0.1-1xL* galaxies at z=7.660, 7.664, and 8.695 whose ISM physics have been the best characterized in a ~30hrs of JWST ERO program. Remarkably, deep NIRSpec detects ~10 rest-optical emission lines from these three galaxies, including the very weak [OIII]4363, which enables us to perform the direct metallicity measure for the first time at z>3. We will 1) investigate the origin of high FIR [OIII]/[CII] ratios in early galaxies, 2) characterize their gas, dust, and obscured properties, and 3) search for companions implied from the JWST data. Similarly, well-characterized galaxies will not be established in the next ~1-2 years, given the scheduled JWST programs, making our targets the best reference of early galaxies to understand the ALMA results in the past and future. Constraining total fluxes of the FIR line/continuum now and swift, deep follow-ups in ALMA cycle10 and JWST cycle2 are crucially important. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2022-10-26T11:59:18.000 |
| 18 | 2013.1.00449.S | 93 | Finding Redshifts for the Most Extreme Starbursts in the Early Universe | We have developed a technique to robustly select high-z (>4) dusty, massive, star forming galaxies using far-IR Herschel/SPIRE data. Follow up of the first handful of sources has proven this technique to be both efficient and reliable, yet the existence of these sources is emphatically not predicted by current models. We have extended this technique by selecting the 'reddest of the red' sources, which are likely to be at even higher-z. We propose to determine what fraction of these sources are, in fact, at z>5 by using ALMA to measure secure, multi-line redshift for 8 such ultra-red sources selected from the HerMES/HeLMS and H-ATLAS projects, providing a powerful check on models. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2015-12-05T20:05:45.000 |
| 19 | 2017.1.00392.S | 42 | Completing a Census of Cloud-Scale ISM Structure in Low Mass Disk Galaxies | We propose to complete a program mapping the molecular ISM of disk galaxies in which ALMA already invested ~11 hr of 12m, ~40 hr of ACA, and ~100 hr of TP time during Cycle 3. Mapping molecular gas at cloud scales (~50 pc) while sampling a diverse range of environments is necessary to understand how the lifecycle of GMCs, the efficiency of star formation, and the coupling of feedback depend on local and global conditions, and affect the evolution of galaxies. We are producing CO(2-1) maps of 18 nearby star-forming disks at ~1'' resolution. The low mass targets are sufficiently CO-bright to efficiently map molecular gas (in contrast to dwarfs) and contain diverse dynamical, chemical, and stellar environments which differ from the conditions in high mass systems. ACA+TP data for the full sample, and 12m-array data for 12 galaxies are in hand. A 10 hr investment of 12m-array time is now necessary to complete this unprecedented high resolution census of molecular gas in low mass disks. Exploring gas, star formation, and feedback at this resolution over this range of environments will produce a unique legacy dataset, especially when combined with in hand data for high mass systems. | Spiral galaxies, Surveys of galaxies | Local Universe | 2020-02-01T00:00:00.000 |
| 20 | 2013.1.00164.S | 17 | CH+(1-0) absorption: the very first probe of turbulent dissipation in high-z galaxies | The growth of galaxies in the Early universe is largely governed by the conversion of massive gas reservoirs into stars. The gas-feeding of star-forming galaxies generates intense turbulence that delays star-formation as long as it is not dissipated: turbulence acts as a mass and energy buffer over timescales that are essentially unknown. The unique chemical properties of CH+ make it a robust tracer of turbulent dissipation. The recent discovery of very bright lensed submillimeter galaxies (SMG) at high-z, combined with the outstanding sensitivity and resolution power of ALMA, opens, for the first time, the possibility of CH+(1-0) absorption spectroscopy against the continuum of 7 SMGs with star-formation rates (SFR) differing by a factor of 7: detections will give turbulent dissipation rates whose scaling with the SFRs will be searched. They will also allow to (1) distinguish infall and outflow from turbulence, (2) trace weakly molecular gas of low density, and (3) image the absorbing gas across the lensed images of the SMGs and along the four star-forming regions in the Eyelash galaxy. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2015-09-02T18:54:53.000 |
| 21 | 2013.1.00118.S | 0 | Unveiling the population of high-redshift submillimeter galaxies with ALMA 1.2 mm imaging | Submillimeter galaxies (SMGs) are dusty star-forming galaxies at high-z that directly trace the most intense episodes of stellar mass build-up in massive galaxies. Despite the large progress in understanding their properties, all we currently know about SMGs is severely affected by the biases imposed by the traditional radio/IR counterpart identification methods. We propose to perform ALMA 1.2 mm continuum imaging of a complete, flux-limited sample of 129 SMGs in the COSMOS field. These observations will allow us to find unambiguous counterparts and thus perform a critical, unbiased analysis of the SMG properties. Taking advantage of the unprecedented multi-wavelength and photometric redshift coverage of the COSMOS field, this will provide a legacy sample to study the cosmic evolution, dust properties, masses and environments of SMGs. Most importantly, we will quantify the intrinsic redshift distribution, providing a conclusive measurement to the abundance of SMGs at z>4. Finally, this study will illuminate the homogeneity or diversity of the SMG population, possibly changing our view of their evolution and role in the formation of massive ellipticals. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-02-17T18:04:48.000 |
| 22 | 2018.1.01146.S | 26 | 4 for 1: resolved CO, CI, dust, and star-forming laws in a binary HyLIRG + binary ULIRG at z=2.41 | HATLAS J084933.4-021443, an ultra-rare system of two HyLIRGs + two merging ULIRGs at z = 2.4, within a 20" aperture, permits highly efficient studies of high-z physics. Our previous observations, which resolved CO, CI 2-1, and dust in all four systems, have revealed rotation-dominated disks, a steep resolved (2.5kpc) 'warm/dense' gas Schmidt-Kennicutt relationship, and gas exhaustion times of 0.5-3Gyr. Here we request 0.15" (1.2kpc) observations of CO, CI (2-1 and 1-0),HCN, HNC, HCO+, 13CO and the dust SED in all four galaxies (1 pointing). This comprehensive resolved study will allow us to: a) determine resolved kinematics and physical conditions; b) measure kinematic and luminosity based gas masses, thus constraining star formation scenarios; c) constrain the radiation field and the presence of AGNs; d) constrain the presence and mass of outflows and winds; e) test CI as a predictor of molecular gas mass; f) obtain resolved Schmidt-Kennicutt relationships for both 'cold' and 'warm/dense' gas; g) test gas to dust ratios and their dependence physical conditions; h) compare to recent hydrodynamic simulations of isolated and merging galaxies. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-01-25T23:13:01.000 |
| 23 | 2023.1.01581.S | 0 | Disclosing the bursty nature of Lyman-alpha emitters at z~3.3 via their carbon emission | Determining the physical conditions of the interstellar medium (ISM) remains essential to understand the formation and evolution of galaxies. This proposal aims to obtain [CII]158um detections of a unique sample of 6 Lyman-alpha emitters at z~3.3 selected by their UV nebular CIII]1908A emission observed in deep spectroscopy surveys. We will combine [CII] and CIII] to measure fundamental ISM conditions using state-of-the-art models, revealing the bursty nature of these galaxies that resembles the properties of galaxies in the Epoch of Reionization (EoR). In particular, we will measure the mean gas density and the deviation from the well-known Kennicutt-Schmidt relation, which are challenging to determine at high-z. This proposal will pave the way for future observations with JWST and ALMA combining UV+FIR spectroscopy in the EoR where intense CIII] emitters are expected to be common, but their true nature remains unknown. | Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies | Galaxy evolution | 2025-04-18T01:23:48.000 |
| 24 | 2015.1.00500.S | 36 | Imaging the Disk and Gas Accretion Around Young Massive Star S255 IR | The answer to how massive stars acquire their large mass is essential to our understanding of the massive star formation process. There is growing observational evidence suggesting that like their low-mass counterparts, newborn massive stars accrete through similar disk-outflow interaction as a scaled-up version of the standard disk-envelope paradigm. Detailed characterization of this process has been greatly hindered by the fact these disks/toroids were barely resolved in previously observations. We propose ALMA observations to investigate the elusive disk in the nearby massive star forming region S255 IR with unprecedented high sensitivity and angular resolution. At an angular resolution of 0.1", direct high quality imaging of dust continuum, and more importantly, molecular line emission will allow us to resolve the disk and determine its physical and kinematical structure. The observations will enable us start addressing whether such disks or toroids around massive young stellar objects are Keplerian and stable; how the disks participate in the accretion process; and how the disks and outflows interact. | Disks around high-mass stars | Disks and planet formation | 2017-07-12T23:23:18.000 |
| 25 | 2021.1.01205.S | 52 | Unveiling the young stellar populations in two close benchmarking sparse young moving groups | One of the major goals in the planet formation field is to establish a connection between the current diverse population of exoplanets with the rich variety of disks found in surveys of large molecular clouds. While the results from these surveys have provided very insightful data to inform planet formation theories, they have focused on crowded star-forming regions (SFRs) and the more sparse young populations have not received the same attention. A significant fraction of stars in the Galaxy are born in these sparse young stellar populations, implying their planet formation has not been probed by systematic surveys at mm-wavelengths. Here we propose a dust and gas detection survey covering the whole stellar populations of the close eta and epsilon Chamaeleontis young stellar associations to extend the findings of surveys of crowded SFRs to these sparse associations and to inform planet formation theories about the effects of environment on the evolution of protoplanetary disks. We propose to observe these two associations with Band 7, providing information on the disk masses, sizes, and presence of structures in disks with a combination of moderate and high angular resolutions. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2022-11-15T18:08:52.000 |
| 26 | 2015.1.01084.S | 7 | Surface emissivity on Kuiper Belt objects | Transneptunian Objects (TNOs) and dynamically-related Centaurs are leftover of planetary formation, which makes their physical characterization of upmost importance. Size / albedo / thermal properties measurements in this population are best achieved by thermal radiometry, and recent surveys with Spitzer and Herschel have provided novel results in the field. ALMA can expand these studies to larger samples and smaller objects, but a limiting factor is the uncertain submm/mm emissivity. Herschel/SPIRE observations of several objects have revealed a decrease of the spectral emissivity longwards of 350 microns, which may result from the effect of (i) sub-surface sounding (ii) scattering of thermal radiation in a highly transparent medium. We will measure the 1.3 mm flux of 6 objects with well-known diameter and albedos, sampling different compositions and albedos, so as to establish their radio emissivity. This will offer the possibility (i) to gain insight into the physical mechanisms at work (ii) to build a wavelength-dependent emissivity function, possibly composition-dependent. This will permit to fully exploit the unique potential of ALMA in the field. | Solar system - Planetary surfaces, Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2017-02-09T16:34:43.000 |
| 27 | 2013.1.00033.S | 13 | The role of infrared radiative pumping for molecular gas emission in AGNs | We propose to thoroughly investigate the strengths of the vibrationally-excited (v2=1f) rotational (J)-transition lines of HCN, HCO+, and HNC lines, in the two AGN-hosting, narrow-molecular-line, luminous infrared galaxies which show detectable HCN v2=1f J=4-3 emission lines. Our immediate objective is to investigate whether an infrared radiative pumping mechanism indeed works more effectively for HCN than HCO+ and HNC, and is responsible for the enhanced HCN emission observed in AGNs, as proposed by theories. ALMA's high-spatial-resolution (<0.6 arcsec) is crucial to probe only AGN-affected molecular gas emission at galaxy nuclei, with minimum contamination from spatially-extended starburst activity in host galaxies. ALMA's high sensitivity (better than a few mJy noise level) is indispensable to clearly address this issue. Our ultimate scientific goal is to establish a physically-understood reliable tool to separate AGNs from stabursts using bright (sub)millimeter molecular emission lines, which can be used to understand the physical nature of dust/gas-rich infrared luminous galaxies from the local to distant universe. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2016-11-25T17:03:50.000 |
| 28 | 2012.A.00020.S | 0 | Paradigm-shifting ALMA observations of the unusually-bright comet C/2012 F6 (Lemmon) | Cometary ices contain material left over from the birth of the solar system, and studying their composition provides an important source of information regarding the physical and chemical conditions of the early Solar Nebula. Previous observations have been unable to ascertain the precise origin of fundamental coma species H2CO, HCN and HNC, and details regarding their possible formation in the coma are currently not well understood. We propose to follow up our recent VLT and APEX studies of the bright comet C/2012 F6 (Lemmon) and map the strong sub-mm emission lines of HCN, HNC, H2CO and CH3OH using ALMA. We will obtain spatially and spectrally-resolved emission profiles to ascertain the origin of these molecules and place constraints on the mechanisms by which they are released into the coma. The proposed investigation could revolutionise our understanding of the origins of HCN, HNC and H2CO in comets. Our proposal is submitted for DDT because F6 Lemmon has far-exceeded earlier expectations for its brightness and gas-production rates. It is currently among the most active comets seen since Hale Bopp, and is expected to remain so for the next few weeks. | Solar system - Comets | Solar system | 2014-01-29T00:00:00.000 |
| 29 | 2023.1.01085.S | 0 | Feedback Physics in a Dusty Star-Forming Outflow Host at Redshift 4.5 | In the last decade, observations of the high-redshift universe have revealed a new population of dust-rich, intensely star-forming galaxies (DSFGs), showing much higher star formation rates than normal galaxies at the same epochs. However, their evolution across cosmic times and relationship to other galaxy populations are still unclear. Given their intensely starbursting nature, we expect stellar feedback to play a significant role in their evolution. Based on observations in the local universe the combination of multiple far-IR OH lines, tracing the warm, nuclear molecular gas, is a powerful probe of feedback. Here, we propose to use a suite of far-IR OH lines to characterize the molecular outflow in a dusty, intensely starforming galaxy at z ~ 4.5. Our proposed observations will trace the multi-phase outflow and provide detailed insight into the physical conditions of feedback in dusty, starbursting galaxies at high z, in addition to the mass outflow rate, outflow energy, and column densities. This is an essential step in constraining the evolution of the bright dusty, starbursting galaxy population, and placing them in the larger context of galaxy evolution. | Starbursts, star formation | Active galaxies | 2025-11-04T17:32:55.000 |
| 30 | 2019.1.01071.S | 8 | CT Cha b: The perfect candidate to detect a circumplanetary disk. | Several planet-mass companions (PMCs) on wide-orbits were imaged around young stars (1-10 Myr). Their estimated mass is just around the brown dwarf to giant planet transition (~13 Jupiter masses), which makes them especially interesting for both star and planet formation theories. Several formation theories exist, but none of them can explain all properties of the currently known PMCs, and their formation mechanism remains unclear. Indirect evidence for disks around PMCs from optical and near-infrared emission exist, but attempts to detect mm dust emission have been unsuccessful. However, gas observations can provide direct evidence for the presence of a circumplanetary disk. The best candidate to do so is CT Cha b. It is the PMC with the widest orbit (500 au), and recent VLT/SPHERE scattered light observations show polarized dust emission from the PMC up to a radius of 20 au, suggesting that the gas disk is at least of similar size. Our proposed gas observations will trace the disk kinematics and allow for a dynamic mass estimate of CT Cha b. Furthermore, they will provide stringent constraints on the disk size and mass, information that is crucial for planet formation theories. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2022-12-07T15:35:06.000 |
| 31 | 2017.1.01093.S | 210 | The role of molecular gas in quenching star formation of green valley galaxies | How the star formation of galaxies gets quenched and how galaxies migrate from the star-forming sequence to the quiescent population remains unanswered. In our cycle 3 project, we obtained CO (1-0) observations for three galaxies in their transitional phase, the so-called `green-valley' galaxies, selected from an integral field unit (IFU) survey of nearby galaxies,`MaNGA'. We found that the molecular gas has a different role in the star formation quenching between bulge and disk. In addition, the data show clear dependence of the kpc-scale specific star formation rate (sSFR) on the gas fraction and star formation efficiency (SFE) in both bulge and disk regions. In order to robustly establish the trends we found based on a limited Cycle 3 sample, we propose to increase the resolved CO(1-0) sample size by observing 25 MaNGA galaxies whose sSFR are below the median value of the star-forming main sequence. The resolved gas observations from ALMA, combined with the resolved stellar populations from MaNGA, will allow us to shed light on the role of cold molecular gas in the star formation history as well as the quenching process in galaxies. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2019-06-28T01:35:49.000 |
| 32 | 2022.1.01538.S | 10 | Imaging Extended [CII] Emission at z=6.15 with Compact Array | As one of the brightest atomic coolant lines in the far-infrared, [CII] 158um line is viewed as a reliable star-formation rate (SFR) indicator up to redshift ~ 6 at least. However, certain ALMA observations of gravitationally lensed, intrinsically faint galaxies at z>6 did not yield robust detection of [CII], raising the concern that [C II] could be underluminous in low metallicity environment, or simply being resolved out because of an extended size, 2-3x larger than UV star-forming regions. We request standalone ACA observation of a giant (~10") Lyman-alpha-emitting arc at z=6.15. With a lensing magnification of ~17, this source could host an intrinsically low SFR down to ~0.6 Msun/yr. Our CASA simulation suggests that previous observations with 12-m array might miss the bulk of extended [CII] emission, which will be detected robustly when combined with the proposed 16-hr ACA observations on-source. Despite being a simple detection experiment, this program will also compare the size/distribution of [CII] emission with those of UV continuum and line width with those of LyA, exploiting the potential of ACA in detecting extended [CII] lines at z>6. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-09-04T15:55:53.000 |
| 33 | 2017.1.00894.S | 105 | Jupiter Family Comet Composition: Unique insights into Disk Midplane Chemistry | We propose to measure the molecular abundances of nitriles (HCN, HNC, HC3N, CH3CN), oxygen-bearing organics (H2CO, CH3OH), and sulfur compounds (SO2, SO, CS) in the Jupiter-family comet (JFC) 21P/GZ. The 2018 apparition of 21P is extremely favorable, offering a rare opportunity to study a JFC in unprecedented detail -- this dynamical class of comets is significantly under-studied in all parent volatiles [15,16]. Furthermore, our target molecules are some of the most under-represented species in compositional studies of all comets (JFCs and Oort cloud comets), such as SO2, HC3N, and CH3CN. In synergy with contemporaneous infrared observations, the proposed ALMA/ACA data will greatly improve our knowledge of JFC chemical compositions. Cometary mixing ratios provide a unique probe of disk mid-plane chemistry, and, through quantitative comparison with protoplanetary disk models, our observations are expected to help advance our knowledge on the formation and composition of the materials that served as the building blocks of our Solar System. | Solar system - Comets | Solar system | 2019-12-27T21:52:44.000 |
| 34 | 2018.1.00556.S | 58 | Unlocking the Potential of the Most Definitive Molecular Tracer of UV-Enhancement: l-C3H+ | The recently-discovered interstellar molecule l-C3H+ appears to be the most sensitive and definitive molecular tracer of enhanced UV-flux ever observed in the ISM. Extensive, deep searches for this species in dozens of sources show its presence exclusively in UV-enhanced regions. Yet, our understanding of the spatial distribution of the molecule within these sources, and the excitation conditions (and abundances) in previously-observed regions, is sorely lacking. Here, we propose ALMA observations following up on prior detections in three PDR regions with the IRAM 30m telescope to understand the spatial distribution, abundance, and excitation of this potentially transformational molecule in our ability to probe the extent of UV-enhanced flux in these and other key regions. The results will be used to refine state-of-the-art PDR chemical modeling codes, and inform related ALMA proposals to observe this molecule in protoplanetary disks. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2020-01-22T23:13:23.000 |
| 35 | 2021.1.01087.S | 104 | Mapping the extended environment of a massive z=4 protocluster candidate discovered in the 2500 deg^2 SPT survey. | We propose spectral scans towards a dense protocluster candidate discovered in the SPT survey, SPT0457-49 at z=3.99. ALMA Cy3&7 observations confirmed this bright LABOCA 870um-unresolved source is host to at least 6 SMGs detected in dust and CO emission within 40". There are 9 additional satellites spanning 5 Mpc, likely tracing the broader structure. We propose deep B3 observations and shallower B4 scans of the brightest LABOCA, as well as B3 observations at modest depth of the satellites. The proposed wider field and resolved observations are essential to obtain an unbiased, coherent census of galaxy population in this structure. Our main goals are (i) characterize the environment by searching for cluster members in the central source; given the high density of SMGs already detected, we expect to detect a plethora of fainter CO emitting galaxies at z=3.99 (ii) determine whether the 9 offset red SPIRE/LABOCA sources (peaking at 500 um) are in the protocluster; and (iii) resolve the 6 core members in CO7-6/CI/H20 to determine whether they are merger driven or relaxed disks, probing gas, dynamical and stellar masses; multi-line diagnostics of the ISM. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2023-02-03T22:54:29.000 |
| 36 | 2019.1.00454.S | 57 | Arp 220 Nuclear Disks at 25 - 50 mas Resolution | We propose to complete our ultra-high resolution imaging of Arp 220 to resolve the gas structures and dynamics in the two nuclear disks. In ALMA Cycles 3 and 5, our projects 2015.1.00113.S and 2017.1.00042.S were scheduled for both long and short baseline imaging in the CO (1-0), (2-1) and (3-2) lines and the CO isotopes. This project was A-ranked in both cycles but so far we have received only the CO (1-0) (high and low resolution imaging) and the CO 2-1) (low resolution). Although the project was carried over to Cycle 6, we do not know if it will be completed in Cycle 6; here we submit the uncompleted part of the original projects. Obviously, if any of the observations are completed in Cycle 6, the duplicate observations proposal here can be omitted. This spectacular imaging will resolve physical radii down to 5 pc within the central gas concentrations -- well within the sphere of influence of the putative super massive black hole. In addition, the CO line ratio and excitation analysisin Arp 220 -- an analog of high z mergers -- will provide a vital foundation for interpreting high z starburst/merging galaxy observations. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2022-07-16T19:24:18.000 |
| 37 | 2015.1.00480.S | 13 | Unveiling the disk around the massive protostar powering the magnetized HH 80-81 jet | HH80-81 represents a unique case where the basic ingredients showing that high-mass protostars form through an accreting disk with a magnetic field are present: A magnetized highly collimated jet; a disk perpendicular to the jet; possible rotating motions of the molecular gas around the massive protostar. There is not any other known massive YSO showing together all these signatures. The goal of this proposal is to confirm and characterize the accretion disk around the powering source of the HH80-81 radio jet, revealing the magtnetic field and the kinematics within the disk. The proposed observations combined with the use of irradiated accretion disk models will allow to unveil the disk and stellar mass, the accretion rate, the disk kinematical behavior and the relevance of the magnetic fields (needed to launch the spectacular jet). Cycle 3 gives the required performance (sensitivity, angular resolution and image fidelity) to unveil for the first time a disk associated with a massive protostar at scales of ~100 AU. | Disks around high-mass stars | Disks and planet formation | 2018-02-17T00:00:00.000 |
| 38 | 2019.2.00112.S | 63 | Moving Past Small Number Statistics in Astrochemistry: An ACA Molecular Survey of 25 Hot Cores | Studies of chemical evolution have traditionally focused on a small number of exceptionally molecularly rich and bright sources due to the historical difficulty in detecting complex interstellar molecules. This small sample size biases our understanding of 'standard' chemical evolution, and prevents calibration of chemical models to standard conditions. Single-dish surveys that have attempted to address this issue by surveying substantially larger sample sizes have suffered from extreme beam dilution, due to the very small angular size of typical chemically rich hot cores. Here, we propose to exploit both the sensitivity and spatial resolution of ALMA to conduct a distance-limited survey of twenty five hot core sources. We target several spectral windows designed to provide the maximal scientific return, and will use the results to calibrate several of the industry-standard models and identify critical areas in which these models need refinement. These ACA observations complement an approved Cycle 7 12-m array for an identical set of sources and spectral coverage. | High-mass star formation, Astrochemistry | ISM and star formation | 2022-10-15T00:13:44.000 |
| 39 | 2015.1.01312.S | 190 | Tracing the evolution of massive protostars | Recent surveys of the Galactic plane have identified large populations of candidate young massive protostars. However we have a very poor understanding of the actual evolutionary status of these sources. The SED based classification schemes used for nearby low mass objects are, alone, inadequate at the large distances of these high mass objects which are embedded in inhomogeneous environments. Here we propose the first comprehensive, systematic, high angular resolution survey of the chemical (and physical) properties of a well selected sample of 39 young high mass embedded sources. This survey will use a single frequency setting to study a range of organic molecular species which trace the evolution of the circumstellar material as a protostar initially heats its environment. The column density and excitation temperature of these species, together with the dust continuum emission, will be used to study how the properties of the circumstellar molecular gas change with source luminosity, spectral energy distribution and other properties with the goal of identifying evolutionary trends. | High-mass star formation | ISM and star formation | 2017-04-05T09:48:34.000 |
| 40 | 2021.1.01197.S | 28 | Resolving the Cold H2 Gas in Nearby Quasar Host Galaxies | Active galactic nuclei (AGN) feedback is believed to be closely related to the processes that govern the mass assembly within galaxies. However, the exact manner in which AGN feedback interplays with their host galaxies interstellar medium (ISM) is still topic of intense debate. Strong gas outflows are suspected to deplete the ISM, removing the cold gas, and further quench the star formation. Strikingly, the more luminous AGNs are found in typical star-forming galaxies, and some even in the regime of starbursts, casting serious doubts about the effectiveness of AGN feedback. Previous surveys targeting the CO emission in quasars demonstrated that molecular gas is abundant within the hosts. ALMA observations of the CO-brighter PG quasars showed that these systems are kinematically regular, and that the hosts molecular gas distribution is compact. We propose to extend the previous surveys by observing the CO-fainter PG quasar hosts and test if the molecular gas properties observed in the gas-richter PG quasars are ubiquitous within the nearby systems. These observations will provide tantalizing clues on how the AGN feedback shape the cold molecular gas reservoir in galaxies. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-10-04T00:00:00.000 |
| 41 | 2022.1.00971.S | 18 | Feebdack or mergers? Detailed characterisation of an exceptional molecular gas ejection at z=1.4 | We propose deep ALMA Band 3 follow-up of ID2299, a massive starburst galaxy at z=1.4 that is expelling a large quantity of molecular gas at ~25000 solar masses per year, as revealed by a broad component detected at 2-6 sigma in CO and [CI] ALMA observations. This object may represent the long-sought observational confirmation of outflow-driven quenching at high-z. However, the triggering mechanism of the ejection is still debated, as a result of the short integration and low resolution of pre-existent data available from ALMA. We thus request a combination of deep medium- (0.8") and high- (0.2") resolution observations in CO(2-1), where the ejection is detected with the highest significance, to rule out a two-galaxy merger, measure the ejection parameters (gas mass, spatial centroid, size, kinematics), and rule out whether the broad component traces a merger-driven tidal tail or a feedback-driven wind. The observations requested for this unique target caught in a critical stage of its evolution will shed light on the mechanisms halting star formation in galaxies of the distant Universe. | Starburst galaxies | Active galaxies | 2024-04-06T09:29:29.000 |
| 42 | 2021.1.00377.S | 190 | A Complete Census of the Molecular Gas Reservoirs in the Antlia Cluster of Galaxies | Galaxy cluster mergers are among the most energetic events in the Universe and they profoundly affect the evolution of their member galaxies. These disturbed clusters represent an intermediate evolutionary stage between lower-density environments, such as fields and groups, and bona-fide, relaxed clusters and thus may provide an important missing link for how galaxies evolve as function of local density. Cairns et al (2019) obtained the first molecular gas measurements in a disturbed cluster using APEX. The survey of the complete population of star-forming galaxies in Antlia has revealed large molecular gas reservoirs in 27 cluster galaxies. Unlike relaxed, virialized clusters, where galaxies become increasingly gas poor toward the cluster core, these Antlia detections are consistent with no gas deficiency compared to field counterparts. We propose ALMA-ACA observations to spatially resolve these molecular gas reservoirs and unveil whether typical environmental effects, such as ram pressure stripping, operate at intermediate cluster evolution stages. This is a resubmission of a program ranked in the top quartile in the Cy7 Supp Call, but with no data taken. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2022-11-29T21:48:33.000 |
| 43 | 2012.1.00076.S | 4 | The evolution in the molecular gas content of Luminous Infrared Galaxies at z = 0.25-0.65 | Massive galaxies in the early Universe are known to form stars at rates >10 times that of galaxies of the same stellar mass today. Measurements of the molecular gas content in galaxies are needed to understand the mechanisms by which galaxies accumulate their gas and convert it into stars, and how these change over time. While observations have shown that the molecular gas fraction has declined from 30-50% at z = 1-2 to 6% at z = 0, little is known about the evolution in gas content at intermediate redshifts, where the assembly of the Hubble sequence occurs. We propose to detect the CO J = 3-2 emission in a sample of 20, spectroscopically confirmed, non-interacting luminous infrared galaxies at z = 0.25-0.65. These observations will allow us to measure the molecular gas mass in these galaxies and to explore its relation to stellar mass and star formation rate at this epoch, bridging the gap in our knowledge of these scaling laws between z = 0 and z > 1. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2015-02-28T17:15:36.000 |
| 44 | 2017.1.00527.S | 367 | The molecular gas and resolved star-formation law in low-redshift SMGs | Galaxies selected by their 850-mum emission remain the best studied submm galaxies (SMGs). SMGs represent a very important galaxy population, since they contribute ~30% to the cosmic star formation at z~2 and provide key constraints in models of galaxy formation and evolution. However, due to their faintness and small sizes -caused by a combination of their distance and their extremely dusty nature- a detailed multi-wavelength analysis of their properties is challenging even with the most powerful current instrumentation. As proven for other populations of star-forming galaxies, low-z analogs can be used to understand and interpret the properties of galaxies in the high-redshift Universe. Using the wide H-ATLAS survey we have isolated a robust sample of 21 low-redshift (zspec < 0.5) SMGs based on their dust temperatures and IR luminosities. We propose (1) 12CO(3-2) ACA observations of our full sample of low-redshift SMGs to measure the properties of their molecular gas; and (2) ALMA observations of dust emission, 12CO(2-1) and [CI](1-0) of two low-redshift SMGs with 12CO(2-1) detection from our IRAM-30m runs to study the resolved star-formation law at 500pc scales. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2019-04-09T11:29:59.000 |
| 45 | 2019.1.00166.S | 10 | Further observations of R Aqr | This is a continuation of successful projects 2017.1.00363.S and 2018.1.00638.S, devoted to study the line and continuum emission in the symbiotic stellar system R Aqr. R Aqr is a binary with an AGB star and a white dwarf that show a strong interaction. Our observations show for the first time the flow of material between stars in a tight binary and the gravitational effects of the secondary on the wind from the AGB: the mass loss is strongly focused in the orbital plane and a double spiral appears. The data are strikingly in agreement with predictions from hydrodynamical models. We also detected the birth of the bipolar jets (down to some AU), which extend several arcmin at other wavelengths. However, the attained resolution, 30-40 mas, is hardly enough to detect the crucial phenomena at orbital scales, since the stars are separated by ~40 mas. In addition, a proper analysis of the data, both in lines and continuum, requires observations at several wavelengths. New observations will also detect the orbital movements, from the continuum emission directly associated to the stars. We propose to observe in bands 7 and 9, including data of the continuum and molecular lines. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2022-07-02T19:08:57.000 |
| 46 | 2022.1.00340.S | 163 | But What About Magnetic Fields? Starspots and an Improved IMF with Dynamical Masses | The distributions of stellar masses and ages in nearby young clusters are benchmarks for understanding the mechanics and timescales of low-mass star formation. These properties are inferred indirectly from comparisons of the observed H-R diagram with the predictions of stellar evolution models. However, young stars exhibit enhanced activity (starspots) from strong magnetic fields that are not treated in the standard models. This activity suggests that masses and ages from standard models are biased: magnetic models predict higher (up to 2x) masses and older (~2-3x) ages than the standard models for the same stellar temperature and luminosity. The effects become more pronounced for later spectral types, which has important implications for the IMF and cluster (mean) ages. We propose to quantify these effects by making model-independent, dynamical mass measurements of young stars in the Lupus region - particularly for later spectral types - based on the Keplerian rotation of their gas disks. Comparisons of these precise (few % level) dynamical masses with standard and magnetic evolutionary models will reveal how starspots influence our view of star and planet formation. | Low-mass star formation | ISM and star formation | 2024-11-03T22:43:43.000 |
| 47 | 2022.1.00315.S | 34 | Testing the vortex hypothesis in a protoplanetary disk | The HD 34282 protoplanetary disk hosts an azimuthal asymmetric structure at ~100 au in mm continuum emission revealed by ALMA observations. Intriguingly, the structure roughly coincides with a one-arm spiral in near-infrared scattered light. Simulations have shown that both are signatures of a vortex. HD 34282 is thus a rare system with a vortex candidate revealed in both scattered light and in dust emission. We will test the vortex hypothesis for the structure by examining two theoretical predictions of vortices: 1) smaller dust traced at shorter wavelengths is less concentrated azimuthally than larger dust traced at longer wavelengths, and 2) dust at the center of a vortex can reach a maximum dust size one order of magnitude or more larger than that in the background ring. Specifically, we will carry out sensitive continuum observations with high resolutions at 4 bands, and constrain the dust properties in the disk via multi-wavelength spectral energy distribution modeling. We will also compare the azimuthal extent of the structure at multiple wavelengths. This program has the potential to provide the most definitive verification of a vortex in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2024-10-03T14:40:41.000 |
| 48 | 2021.1.01291.S | 37 | Molecular gas distributions in compact dusty star-forming galaxies at z=2 | Recent ALMA observations of massive star-forming galaxies have revealed that the dust continuum emission is more compact than the optical continuum emission. This finding potentially suggests radially inward transport of gas (compaction), but the spatial distribution of molecular gas has been little investigated by CO observtions. We here propose to make deep 0.5"-resolution observations of CO(3-2) emission line in six compact dusty star-forming galaxies at z=2 in JWST/NIRCam deep fields. The half-light radius of the 870 um continuum emission is less than 1 kpc. We will measure the CO sizes by the proposed observations, and threafter compare them with the 870 um and the rest-optical sizes to study the difference in the distributions of molecular gas, dust, and stars. If the CO sizes are smaller than the stellar mass sizes, it would support the compaction scenario holds, and massive galaxies will rapidly form a dense core via concentration of gas. Otherwise, the star formation efficiency would become higher, owing to dense gas in the galaxy center, thereby resulting in a compact starburst. | Starburst galaxies | Active galaxies | 2023-08-05T06:28:41.000 |
| 49 | 2013.1.01114.S | 5 | Control of Star Formation in Massive Filamentary Clouds: Orion | The Herschel mission has revealed omnipresent filamentary structures in molecular clouds. Such structures possibly govern the entire star formation process in the interstellar medium. In this picture, high-mass stars and star-clusters form preferentially in massive filaments whose properties differ from those of low-mass ones, demonstrating a strong environmental dependence. What is crucially missing is the knowledge of how massive filaments fragment and collapse to form stars. With ALMA, we will fill this knowledge gap by describing the fragmentation of the most nearby massive filament, the Orion filament, in great detail. We will observe the filament in 110 GHz continuum and C18O line emission. These data, together with our Herschel and LABOCA data, will provide the highest-fidelity column density data ever obtained for a molecular cloud, from several-parsec scales to 1700 AU scales. We will determine the fragmentation mode of the filament with our novel techniques that recover both the volume density and kinematic structure. We will then connect this analysis with our protostellar census, establishing how filament fragmentation connects to the protostars within. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-02-06T18:56:56.000 |
| 50 | 2023.1.01318.S | 0 | Does the nucleus in G208.62-19.20-N2 harbor a first hydrostatic core? | A prestellar core, G208.68-19.20-N2 (hereafter G208-N2), located in Orion Molecular Cloud 3, contains a compact object, referred to as the "nucleus," which is embedded in a filamentary structure with a density of 10^7 cm^-3. The nucleus has a radius of approximately 220 au and an extremely high density of over 10^9 cm^-3. It is more massive and denser than the first hydrostatic core (FHSC) candidate, rho-Oph A SM1N. The chemical properties of the nucleus, such as the decrease in N2D+ and o-H2D+ abundances, suggest the possibility of an embedded source. However, no CO outflow localized to the nucleus has been detected. An H2CO 3(0,3)--2(0,2) line image in the archive, obtained with a coarse spectral resolution of ~1.55 km/s, revealed two compact emission spots near the nucleus, which could originate from a low-velocity (<1 km/s) outflow driven by the "putative" central source in the nucleus. The proposed observations aim to test this hypothesis using the H2CO (2(0,2)-1(0,1)) and CH3OH 3k--2k lines in Band 4, with a high spectral resolution of ~0.2 km/s. If the outflow is confirmed, the nucleus in G208-N2 will become the most promising FHSC candidate. | Low-mass star formation | ISM and star formation | 2024-12-20T18:26:39.000 |
| 51 | 2013.1.01225.S | 5 | Accretion matter onto the central engine of the nearby radio galaxy NGC 1052 | We propose observations of molecular (CO, HCO+, HCN, and SiO), dust, bremsstrahlung, and recombination lines (H26alpha and H30alpha) toward the center of the radio galaxy NGC 1052 to understand mass accretion processes from the host galaxy onto the central engine of active galactic nuclei (AGNs). Mass accretion is a key process to characterize AGN activity and evolution of super-massivi black holes (SMBHs), while it is poorly understood in terms of controling parameter of accretion rate, the origin of accretion matter, and mechanism of angular-momentum transfer. We aim to identify the accretion matter in the transition region where is the boundary between the SMBH gravisphere and galactic rotation. NGC 1052 is the best target because of proximity (20 Mpc) and evidence for mass condensation in plasma, HI, and molecular gas such as H2O, OH, CO, HCN, and HCO+, within the SMBH gravisphere. ALMA will reveal (1) distribution of accretion matter in dust, molecular gas, ionized gas, and plasma, (2) velocity fields and then accretion rate in the transition region. The results will unveil the origin of the accretion matter and discriminate mechanisms of angular-momentum transfer. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2016-12-01T17:35:00.000 |
| 52 | 2013.1.00059.S | 3 | Resolving the molecular gas and dust in a unique star forming disk galaxy z~2 | We propose to obtain simultaneous high-resolution imaging of the CO 4-3 and [CI] 1-0 emission lines and dust continuum in the best characterized star-forming disk galaxy at z~2. These observations will provide a unique test on the predicted modes of gas accretion by resolving the kinematics and distribution of the molecular gas into kpc-scale regions of active star formation. This will enable an unprecendented view to the obscured star-forming regions that are hidden to the available optical/UV imaging and spectroscopy. We will be able to (1) perform accurate modeling of the galaxy kinematics (kinemetry); (2) characterize the molecular gas and star forming clumps; (3) test star formation laws (gas vs SFR surface densities) in kpc scales, and (4) use their line ratios as a proxy to the fraction of dense gas mass (versus total) to probe the gas excitation in kpc scales. In combination with the previous measurements of CO 3-2/1-0, the proposed observations will allow us to put into context the derived physical properties of the ISM (Tkin, n_H2) for a comprehensive study about the properties of this galaxy. | Starburst galaxies | Active galaxies | 2016-12-01T21:18:11.000 |
| 53 | 2013.1.00526.S | 7 | [CII] Emission from H I - Selected Galaxies | We propose to image directly, for the first time, [CII] 158 micron line emission from the neutral gas associated with two damped Lyman alpha absorption systems (DLAs), i.e., HI-rich galaxies identified in absorption against bright background quasars. The objects at z=1.7947 and z=1.9199 were selected using high resolution spectroscopy for the presence of (1) strong CII*1335.7 absorption lines and (2) emission properties indicating the presence of substantial ongoing star formation. Added to the high metallicities and large kinematic line widths, these properties imply the presence of strong [CII] 158 micron emission. We estimate a 5 sigma detection in 1 hour observing on each object with the cycle 2 compact array. If successful, this will establish CII* imaging with ALMA as the path forward to a prime objective of galaxy-formation research: assessing the mass, kinematic structure, and morphology of these HI-selected galaxies. | Damped Lyman Alpha (DLA) systems, Galaxy structure & evolution | Cosmology | 2015-10-02T13:42:03.000 |
| 54 | 2018.1.00012.S | 62 | Resolving the Black Hole Sphere of Influence in a Quasar at z~7 | Luminous quasars at z>6 are thought to host accreting massive black holes (BHs) with masses >10^9 Msun, rivaling numerous BHs at z=0. At z>6, the Universe's age is less than 1 Gyr and assembling BHs in such a short cosmic time remains a major theoretical challenge. Given their incredible masses, these BHs are thought to be hosted by very massive galaxies, but no evidence for such massive hosts has been found, despite numerous observational attempts. These puzzles (assembly timescales, missing massive hosts) can be solved if the BH masses are severely overestimated: their BH masses are derived by greatly extrapolating from locally calibrated scaling relations. Using ALMA, we propose to make the first kinematic mass estimate of one of the brightest z>6 quasars known, J2348-3054 at z=6.9. Our previous ALMA imaging demonstrates that it contains compact (<0.5kpc) and bright [CII] emission, an ideal tracer for kinematics. Together with the unique resolving power of ALMA, these properties mean that we can resolve the sphere of influence, obtain an independent measurement of its central BH mass, and investigate if indeed the BH is less massive than thought based on local scaling relations. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2020-11-21T00:40:02.000 |
| 55 | 2013.1.00166.S | 9 | Unravelling the dust formation process in oxygen-rich AGB stars | As of today, the mechanism triggering the onset of the stellar wind and mass-loss rate in O-rich AGB stars is not yet understood: (1) We still do not know which are the first little dust seeds formed. (2) Launching a wind seems only possible when the grains are already quite large close to the star. (3) It has been hypothesized that the primary dust species in low and high mass-loss rate AGB stars are different. With ALMA, it is possible for the first time to get decisive information on the chemical processes, dynamics, and geometrical structure in the dust forming region of O-rich AGB stars. With ALMA band 7 in extended configuration, we can spatially resolve the dust forming region in 2 cornerstone O-rich AGB stars, being the best representatives for low and high mass-loss rate AGB stars: R Dor and IK Tau. By observing key molecular species contributing to the formation of dust grains (MgO, MgOH, AlO, AlOH, TiO, TiO2, SiO, H2O, CaOH, NaCl, FeO, and MgS), we will be able to answer key questions on the efficiency of gas depletion by condensing onto dust grains, the dynamical structure in the dust forming region and the spatial correlation between the gas and dust species. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2016-12-16T00:00:00.000 |
| 56 | 2017.1.00901.S | 90 | Resolving the Cloud-Cluster Ecosystem in M33 | We propose ACA 7m observations of the inner disk of M33, over a region which matches a new six-band photometric survey being conducted by the Hubble Space Telescope. The new HST survey will provide an unmatchable perspective on the cluster population and dust extinction map over a 25 square kpc region. By combining ACA-only observations with an in-hand map of the galaxy using the IRAM 30m telescope, we will achieve a high quality map of CO(2-1) over the same region as the HST survey7 with 7" = 25 pc linear resolution. These data will constrain the lifetimes, mass accretion rates, and cluster formation properties of the molecular cloud population. These new results are essential for understanding how the structure of the molecular ISM and the evolution of clouds controls the effectiveness of stellar feedback. We will study the local variations in the CO-to-H2 conversion factor by pairing the CO data with high resolution HI (<= 6" resolution) and the dust extinction map produced by HST (7" resolution). This will isolate regions that are CO-dark molecular gas. Despite the northern declination, CASA simulations of our observation strategy show high quality maps will be achieved. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2020-03-17T00:00:00.000 |
| 57 | 2013.1.00704.S | 4 | Deep dust continuum observations of giant Lya nebulae at z=3.1 | We propose band 7 dust continuum observations of 4 giant Lya nebulae (LABs) at z=3.1 with different morphological types (2 spherical and 2 filamentary LABs). The spherical LABs could be made from gas outflows (superwinds) from starbursts induced by frequent galaxy-galaxy mergers, while the filamentary LABs may trace continuos gas inflows (cold streams) along the underlying dark matter filaments. To test this interpretation, we request 350 GHz continuum observations down to a sensitivity of rms=0.04mJy to identify any associated dusty starbursts with star formation rate, SFR > 25 Msun/yr. The angular resolution of 1.1" (8kpc at z=3.1) achievale with the most compact configuration is small enough to examine if the starburst regions exceed the SFR surface density threshold for superwinds, 0.1 Msun/yr/kpc^2, which can drive substantial gas outflows within the LABs. With 4.6 hours of observations we will identify the key processes forming these giant Lya-emitting clouds, which may be more widely relevant for galaxy formation and the large-scale gas circulation between galaxies and the surroundings. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2016-07-03T10:24:36.000 |
| 58 | 2018.1.00477.S | 159 | The molecular gas in low-redshift SMGs | Galaxies selected by their 850-mum emission remain the best studied submm galaxies (SMGs). SMGs represent a very important galaxy population, since they contribute ~30% to the cosmic star formation at z~2 and provide key constraints in models of galaxy formation and evolution. However, due to their faintness and small sizes -caused by a combination of their distance and their extremely dusty nature- a detailed multi-wavelength analysis of their properties is challenging even with the most powerful current instrumentation. As proven for other populations of star-forming galaxies, low-z analogs can be used to understand and interpret the properties of galaxies in the high-redshift Universe. Using the wide H-ATLAS survey we have isolated a robust sample of 44 low-redshift (zspec < 0.5) SMGs based on their dust temperatures and IR luminosities. We propose to finish the 12CO(3-2) ACA observations of our full sample of low-redshift SMGs (ongoing in Cycle 5, but only nine have been observed so far) to measure the properties of their molecular gas. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2019-12-13T15:09:09.000 |
| 59 | 2019.1.01845.S | 16 | CO(J=1-0) mapping observation of NGC1316 at a scale of 50 pc | We propose CO(J=1-0) mapping observations of NGC1316 (Fornax A) at a 50-pc scale to detect giant molecular clouds (GMCs), which are generally forming stars in spiral galaxies, and investigate the origin of its low star formation (SF) activity of this galaxy. In our cycle-5 ACA observations, we find abundant molecular gas (5x10^8 Msun) despite its low SF activity and reveal complex spatial distribution and velocity field, which cannot be explained only by rotating disk. We also find that the nuclear jet bends at the vicnity of the CO peak, suggesting jet-ISM interaction. We discuss the reasons of the low SF based on the virial analysis of GMCs and RADEX calculation using archival higher-J CO data in the context of the jet-ISM interaction. | Early-type galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2021-03-12T18:04:02.000 |
| 60 | 2017.1.00167.S | 25 | What lies beyond Exo-Jupiter planets? | We propose to image the debris disk of the nearby (17pc) 1Gyr-old F9V star q1Eri in band 7 to determine the disk structure at a (0.7") resolution ~5 times better than previous observations. This system hosts an Exo-Jupiter planet at 2au on a low (but potentially non-zero) eccentricity orbit, as well as an asymmetric debris disk at ~100au which could be eccentric or clumpy. The lack of correlation between systems with Exo-Jupiters and those with debris is surprising given predictions of formation scenarios in which Exo-Jupiters get their eccentricities from dynamical instabilities. The proposed images will determine the origin of the asymmetry in the disk, as well as the radial distribution of material. Models are in place to interpret the observed structure in terms of unseen planets in the outer regions and their formation and evolution. This will throw light on what lies in the empty region 2-70au which holds clues to the origin and nature of systems with Exo-Jupiter planets and why they exhibit no correlation with outer debris. The proximity and sub-mm brightness of q1Eri make it uniquely placed for studying the class of Exo-Jupiter systems. | Debris disks | Disks and planet formation | 2019-07-16T12:07:08.000 |
| 61 | 2017.1.01103.T | 46 | Characterizing Rapid sub-mm Variability in a Bright Black Hole X-ray Binary Outburst | Relativistic jets are fundamentally linked to the accretion process onto compact objects. This makes objects that evolve rapidly through different states of accretion strong probes of jet phenomena. Entire outbursts of black hole X-ray binaries (BHXBs) can evolve on days-months timescales, making them ideal targets. While broad-band spectral measurements are traditionally used to constrain jet properties during BHXB outbursts, variability measurements offer a new avenue to probe jet properties. Our team has recently identified extreme flux variability in jet emission from BHXBs at 5-666 GHz. We propose targeting the next bright (> 50 mJy) outbursting BHXB with a 4 hr ALMA Band 7 ToO observation. With these data we will characterize sub-mm flux variability on timescales of seconds-hours in a BHXB, constraining the jet size and the time lag between the Band 7 subbands. By combining this ALMA observation with our approved VLA, VLBA, SMA, and ASTROSAT ToO projects, we will create an additional detailed probe of jet physics by comparing BHXB jet and accretion variability across radio, sub-mm, & X-ray frequencies, all while simultaneously tracking changes in jet morphology. | Black holes, Transients | Stars and stellar evolution | 2019-08-13T14:08:25.000 |
| 62 | 2012.1.00385.S | 3 | Detailed structure of the Eta Corvi debris disk | This proposal is to image the debris disk around the nearby star eta Corvi at 1.2" (20AU) resolution using ALMA band 7 continuum observations in compact configuration. This is the archetypal two-component debris disk in which there is dust at both 150AU (from a Kuiper belt analogue) and 1.5AU (from a zodiacal cloud analogue). Previous sub-mm imaging has pinpointed the radial location of the system's Kuiper belt at 150AU, but its detailed structure is unknown. This uncertainty leaves a wide range of possible interpretations for the planetary system architecture and status of planet formation. Distinguishing between the possibilities is particularly important for explaining the 1.5AU dust that is thought to be fed by the Kuiper belt analogue through interactions with a planetary system, possibly due to a recent dynamical instability reminiscent of the Solar System's Late Heavy Bombardment. Given the disk's well-known sub-mm flux and spatial extent, we show that ALMA cycle 1 observations will be able to distinguish between the different models and significantly constrain the outcome of planet formation in this unique system. | Debris disks | Disks and planet formation | 2016-12-17T00:00:00.000 |
| 63 | 2016.1.00813.S | 31 | Resolving Structure in the Planet Forming Regions of the Compact Binary Protostar GV Tau | GV Tau is a young binary system whose central protostars are each surrounded by a protoplanetary disk which has been estimated to be unusually massive and compact. If the mass estimates are correct, GV Tau N & S may be the first disks known to have sufficient material within their planet forming regions to form giant planets. Their estimated >0.01 solar masses within 30 AU make them potentially true Minimum Mass Solar Nebula equivalents. Furthermore, there is some evidence that dust grain growth and planet formation may already be significantly advanced in these disks. We propose to use ALMA to, for the first time, resolve the compact protoplanetary disks around the GV Tau protostars and determine their structures and masses. We will also use multi-wavelength ALMA observations to constrain dust opacity and particle sizes within the disks, and spatially and spectrally resolve Keplerian rotation in the disks and measure dynamical masses of the protostars. This project will be an interesting case study of a young binary system whose protoplanetary disks may represent the first known analogs of our own primordial Solar System. | Disks around low-mass stars | Disks and planet formation | 2018-12-05T13:38:12.000 |
| 64 | 2019.1.00910.S | 12 | Remnant disks around young massive stellar objects in M17 | With ALMA we want to make the next crucial step in understanding the final stages of massive star formation and of disk survival beyond the embedded stage. The proposed observations search for reservoirs of cold dust and gas around 4 optically revealed massive pre-main-sequence stars (6-12 solar mass). These PMS stars, located in M17, provide a unique opportunity to study the final phase of the formation process as both stellar and disk properties may be constrained. The photosphere of these still contracting PMS stars is exposed, while their optical and near-infrared spectra show gaseous disks, through emission lines of atomic and molecular species that originate in the inner disk region. These inner disk regions are also observed photometrically up to 20 micron as infrared excess. Observing these targets with ALMA would allow, for the first time, to detect and constrain global disk properties by probing the extended cold outer disk where the bulk of the mass resides. This will greatly further our understanding of massive star assembly and of high-mass star disk dispersal, and lay important ground for answering the question: do planets form around massive stars? | Disks around high-mass stars | Disks and planet formation | 2022-11-09T02:55:51.000 |
| 65 | 2011.0.00531.S | 0 | Discovery and characterization of disk winds from a newly discovered class of protoplanetary disks v4.1 | High-resolution spectroscopy and spectroastrometry in the infrared have revealed a new class of protoplanetary disks, displaying evidence for low-velocity disk winds (namely centrally-peaked, non-Keplerian line profiles originating from AU-scale emitting regions). The disks are also characterized by high accretion rates, and especially strong molecular emission (including from CO, H2O, HCN, C2H2 and CO2). These disks are a potential evolutionary link between stage I disks with envelopes and strong ouflows, and the more quiescent stage II disks, which are the birthplaces of planetary systems. We propose to use ALMA to search for the outer disk (>50 AU) counterpart of the molecular inner disk wind in AS 205N, the prototypical disk wind source. The detection of the outer wind will confirm the models developed for the inner disk and strongly constrain the full kinematic and chemical structure of molecular disk winds, as well as the ultimate fate of the outflowing material. The confirmation of such winds could have important implications for our understanding of the dynamic nature of the planet formation environment, and our interpretation of disk observations. | Disks around low-mass stars, Outflows, jets and ionized winds | Disks and planet formation | 2013-06-21T20:45:00.000 |
| 66 | 2022.1.00793.S | 10 | When terrestrial planets collide: imaging the aftermath of an impact in the Solar neighbourhood | Terrestrial planet formation continues past the gas-rich protoplanetary phase, in 10-100 Myr-old planetary systems. This is the era of giant impacts, where embryos grow through collisions to form terrestrial planets. The HD172555 system is, to date, the only one with conclusive evidence of an impact in the Solar neighbourhood, amenable to characterization. Warm dust with the unique spectral fingerprint of an impact and the recent ALMA detection of CO gas from atmospheric stripping at 8 au inequivocably represent the leftovers of a planetary collision. We propose a deep, high-resolution (0.1") ALMA Band 7 program to resolve the aftermath of this giant impact, measuring the spatial distribution of the debris and its molecular composition. These observables will constrain the progenitor mass, the timing since the collision and the post-impact gas chemistry of an extrasolar terrestrial impact for the first time. Through this program, we will exploit the only opportunity we have to image the aftermath of a giant impact in our Solar neighbourhood, and in doing so constrain models of planetary-scale collisions in unprecedented detail. | Debris disks, Exo-planets | Disks and planet formation | 2024-06-13T18:01:23.000 |
| 67 | 2023.1.00615.S | 0 | Structure and kinematics of the complete freeze-out zone in a prestellar core | The interiors of molecular cloud cores have very high densities and low temperatures before the protostellar collapse sets in. It has been suggested that at this stage, C-, N-, and O-bearing molecules are almost completely frozen onto dust grains within some 500 au from the centre, and that the H2D+ and D2H+ ions are the best probes of the gas kinematics there. Here we propose to test the validity of this prediction towards the pre-stellar core Ophiuchus/H-MM1, where a recent VLA mapping shows a severe depletion of ammonia. We wish to image the nucleus of this core in the line of (ortho)H2D+ at 372 GHz and in 0.8 mm dust continuum. Lines of N2H+ and DCO+ with high critical densities are included in the spectral setup. If the complete depletion model is correct, H2D+ shows the same structure as cold dust probed by submillimetre continuum, whereas N2H+ and DCO+ should correlate poorly with H2D+ and dust, despite the favourable excitation conditions. The proposed observations will reveal the structure and the velocity field in the centre of a prestellar core at a high spatial resolution, providing a useful case study of conditions leading to the formation of a stellar system. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 3000-01-01T00:00:00.000 |
| 68 | 2013.1.00234.S | 5 | Initial gas structure in a cold, massive clump: cluster formation in its earliest stages | The two main models for high-mass star formation, `core accretion' and `competitive accretion,'predict different internal structures for cluster forming clumps only in the very earliest stages. The best way to distinguish between these models therefore is to identify a cold, cluster forming clump and measure its internal structure directly. The core mass function (CMF) is especially diagnostic: in the early stages `core accretion' predicts high-mass cores and a CMF resembling the initial mass function, but `competitive accretion' predicts no high-mass cores and a CMF more sharply peaked around ~1 Msun. Using Galactic Plane molecular line and dust continuum surveys, we have found a single clump, G331.372-00.116, that satisfies all the requirements (cold, dense, and high-mass) for a cluster forming clump in a very early stage. We will use ALMA to measure its internal structure, deduce its core mass function, and determine their virial states. Our simulations show that ALMA has sufficient sensitivity and angular resolution to measure the CMF reliably and to distinguish between the predictions of `core accretion' and `competitive accretion.' | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-08-21T18:30:49.000 |
| 69 | 2016.1.00496.S | 96 | Searching for maser emission in X-ray binaries | We propose to search for maser emission associated with jet-excited shocks and accretion discs in a sample of black hole and neutron star X-ray binaries. If found, high brightness temperature masers will enable probing of molecular/atomic gas conditions in the binaries at high angular resolution, and in the future will provide precise measurements on jet energetics and magnetic fields. They may also enable to determine the distance to the systems, often one of the parameters preventing their characterisation. The jet energetics are expected to be different for the proposed sources that span a range of sizes, accretion states and different compact objects (a black hole or a neutron star). Thus, the detection of masers in one or several objects of our sample would open the possibility of associating jet energetics to the characteristics of the binary and consequently to improve our understanding of the mechanisms that trigger and suppress jet formation, which remain a mystery up to date. | Pulsars and neutron stars, Black holes | Stars and stellar evolution | 2018-08-25T00:00:00.000 |
| 70 | 2023.1.01657.S | 0 | A band 10 molecular line survey toward a hot circumplanetary disk | Being the only circumplanetary disk (CPD) where molecular line emission is detected to date, AS 209b offers a unique opportunity to study the physical, thermal, chemical, and dynamical properties of a CPD. Interestingly, there is an increasing amount of observational evidence that AS 209b's CPD is hot, in an agreement with theoretical and numerical studies of CPDs. Leveraging the unparalleled spectral resolving power of R~10^6 in Band 10 in continuum basebands, which offers a 450 m/s velocity resolution, coincident with AS 209b's line width, we propose to carry out a chemical survey of high excitation lines. With only 1.18 hours of on source time, our program will simultaneously observe tens of major molecular lines, including 13CO, C18O, SO, SO2, H2CO, CH3OH, H13CN, and HC15N, which will provide us with crucial and solely needed concstraints on CPD properties. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 71 | 2019.1.01098.S | 3 | Resolved (Sub)millimeter Wavelength Imaging of Betelgeuse during the 'Months of Betelgeuse (MOB)' Campaign | The red supergiant (RSG) phase marks a short-lived period near the end of the lives of massive stars, during which the star undergoes a period of intensive mass loss. This mass loss has a profound effect on the subsequent evolution of the star, including whether the star will ultimately explode as a supernova. However, the details of the mass-loss process for RSGs, including its driving mechanism, geometry, and timescale, remain poorly understood. We propose long-baseline ALMA observations of the RSG archetype Betelgeuse to provide new insights into these questions through spatially resolved imaging and spectroscopy of the dynamic surface of this star. We will use multi-frequency continuum observations to measure the photospheric size, shape, and brightness temperature at different atmospheric depths and to map stellar surface features such as giant convective cells. We will also measure spatially resolved gas kinematics using lines of SiO and CO, both in emission and in absorption across the stellar disk. These ALMA data will comprise part of an intensive, 3-year, multi-wavelength campaign targeting Betelgeuse spanning 2019-2021. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2023-03-25T21:47:42.000 |
| 72 | 2016.1.00902.S | 70 | Formation of VLM stars and BD in Lambda Orionis Star Forming Region (LOSFR) II. ACA view of Barnard 35 | For over 10 years, our group has led an ambitious multi-wavelength project to study key aspects of stellar and substellar formation in the LOSFR. For the central cluster, we determined the membership, IMF, and constrained possible substellar formation mechanisms, activity, accretion, disk fractions. One of its dark clouds, B30, has been observed from optical to radio; we studied the earliest stages of substellar objects as well as the radio data. A Cycle 4 proposal is submitted to confirm the nature of 3 candidates. With this proposal we focus on the other dark cloud of the SFR, B35, for which we have data from X-rays to the far-infrared, but we are missing the submm part to complete not only the star formation view of this dark cloud, but of the complex as a whole. In particular, we propose ACA stand-alone Band 6 observations (along with an APEX project) to: i) obtain spectral information on sources detected in both projects,ii) improve our selection function, regardless of the APEX observations, to identify candidates to be followed up with the 12m array, iii) build a larger poll of pre/proto-substellar objects to put strong constraints on the proposed formation mechanisms. | Low-mass star formation | ISM and star formation | 2019-06-20T00:00:00.000 |
| 73 | 2011.0.00046.S | 0 | The first insight into the resolved molecular gas properties of a host galaxy of gamma-ray burst 980425 v1.3 | Long-duration gamma-ray bursts (GRBs) have been found, at least in some cases, to be associated with violent and luminous supernovae. Such massive stars have very short lifetimes and therefore GRBs pinpoint the location of galaxies that have recently undergone an episode of star-formation. Here we propose to critically assess this issue using the determination of the star formation efficiency for the closest GRB host galaxy. This is crucial because GRBs are potentially excellent tracers of the global star formation history, which is of fundamental importance to our understanding of galaxy formation. However, this kind of study requires prior detailed investigation of GRB host galaxies, which has not been fully addressed yet. GRB 980425 associated with SN 1998bw is the closest known GRB (redshift z=0.0085), therefore it is an excellent laboratory for detailed GRB studies. The interplay between dust thermal emission, radio emission and star-formation is not yet well understood even in the closest known GRB host. Moreover, the properties of molecular gas are very poorly understood for GRB hosts, since none of them was detected spectroscopically in the far-IR, which is necessary to measure the gas mass. ALMA will provide an important step forward with both of these issues. Here we propose a detailed study of the closest known GRB host. From the CO(1-0) observation of the host of GRB 980425 we will derive its molecular gas mass. These will lead to an understanding of whether the GRB 980425 host can be regarded as a normal star-forming galaxy, or its star formation rate is enhanced. This will have consequences for interpretation of GRBs as tracers of star formation in the Universe. | Gamma Ray Bursts (GRB) | Cosmology | 2014-02-15T08:54:00.000 |
| 74 | 2021.1.00211.S | 29 | The ultimate test for quasar feedback in the early Universe: ultradeep observations of the most luminous quasar at z>6 | Quasar feedback is deemed as a fundamental ingredient for galaxy evolution and transformation. The detection of passive, massive and old galaxies at z~4 requires extreme quasar feedback to be already active by z>6. Yet, it has been suggested that at z~6 quasar-driven massive and energetic outflows are absent or ineffective in suppressing star formation in their host galaxies at the required levels. However, previous observations may have been plagued but lack of sensitivity to extended emission required to detect outflows and/or by issues associated with stacking techniques. We propose the ultimate test for the quasar feedback at z>6 by obtaining very deep observations of [CII] and of low-frequency continuum, with configurations optimised to extended emission, in order to detect and characterise the properties of the outflow driven by this quasar, at the peak of its activity and BH accretion, and also to detect its effect on the halo heating through the SZ effect, which may result into a delayed feedback (hence quenching by starvation) already in place at such early epoch. | Outflows, jets, feedback | Active galaxies | 2023-02-22T00:00:00.000 |
| 75 | 2022.1.00410.S | 10 | Testing the AGN Torus Paradigm with the ALMA [CI] Observations | The geometrically thick disk has been postulated in the circumnuclear region of active galactic nuclei (AGNs) as an origin of the obscuration of the emission in the vicinity of central engines. In this "unified scheme" of AGNs, physical mechanism that supports the thickness of the disk has been a long-standing question. Recent state-of-art numerical simulations suggest that outflowing atomic gas driven by the radiation pressure can produce quasi-steady, thick disk at the scale of a few to tens of parsec around AGNs. However, such a geometrically thick disk of the atomic gas has been suggested by a high velocity dispersion of the gas in only one Seyfert galaxy, but not verified morphologically. We propose to observe the [CI] (neutral atomic carbon) in the circumnuclear region of NGC 5506. This source is one of the most luminous Seyfert type-2 galaxies in nearby Universe, and thereby a significant outflow of atomic gas is expected to be present because of a strong radiation pressure. Its edge-on view also helps to easily identify the thick disk morphologically. The proposed observation can answer if the atomic gas is the main component of the thick disk that can obscure the AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-05-03T22:44:09.000 |
| 76 | 2019.1.00665.S | 8 | Callisto's crucial H2O atmosphere | Callisto, the outermost of the Galilean moons, has surprised us several times. Despite being geologically least active and least differentiated of Jupiter's large moons, the presence of a subsurface liquid ocean was inferred from induced magnetic field measurements by the Galileo spacecraft. Callisto also likely has the fourth most dense atmosphere of all Solar System satellites and a significant and variable ionosphere was found. While one of the main atmospheric species, O2, could be confirmed by HST observations, the expected dominant dayside species, H2O, was never measured nor detected. The relative abundance of H2O yet plays a decisive role for Callisto's ionosphere: if H2O is highly abundant, the electric conductivity and magnetic induction in the ionosphere is similar to those in the subsurface saline water layer - challenging the magnetic field evidence for the putative ocean. Only ALMA is sensitive enough to detect the expected H2O at Callisto: The proposed observations of the 183 GHz H2O line will provide the first measurements of Callisto's dayside water atmosphere. The results will either support or critically question the existence of Callisto's water ocean. | Debris disks | Disks and planet formation | 2024-01-28T00:00:00.000 |
| 77 | 2021.1.00761.S | 21 | Quantifying the molecular gas reservoirs of post-starburst AGN hosts | ALMA observations of a single recently-quenched AGN host at z~0.6 revealed dramatic and unexpected CO(2-1) emission despite suppressed star formation: >10^10.5Msun of molecular gas stretches tens of kpc out from the galaxy's center. Feedback from active galactic nuclei (AGN) is often invoked to shut down star formation-- with this unique galaxy, ALMA may have caught AGN in the act. However, this single object is insufficient to build a statistical link between AGN activity, molecular outflows, and quenching. Here we propose observations of six additional post-starburst AGN hosts from the same parent sample. These galaxies are ideal ALMA targets: they have existing optical spectroscopy and deep high-resolution imaging, and we expect to detect gas given their young stellar ages. We will quantify the fraction of post-starburst AGN hosts that have molecular gas on extended spatial scales, then test whether the gas properties correlate with AGN luminosity, time since quenching, or the location of optical tidal features. This analysis will help pin down the role of AGN in quenching. | Galaxy structure & evolution | Galaxy evolution | 2023-09-21T22:50:00.000 |
| 78 | 2019.1.01528.S | 161 | A new Benchmark for CO Excitation in Normal High-z Galaxies | Observations of molecular gas in high redshift galaxies rely critically on the correction factors between the ground and excited states of CO, the golden standard to measure molecular gas masses. Yet, excitation studies of normal galaxies at high-z are still limited to a very small number of sources and transitions. Here, we propose to greatly expand our knowledge by observing a reference sample of 13 galaxies from the ALMA Spectroscopic Survey (ASPECS) in the Hubble Ultra Deep Field. These galaxies range from being on, above and below the galaxy main sequence at z=1-3. All targets have deep CO, [CI] and continuum data in Band 3 and 6 from the ASPECS Large Program and benefit from a wealth of multi-wavelength data. The requested observations are critical to break existing degeneracies in the CO excitation, CO-to-H2 conversion factor and physical ISM conditions. We will observe low and high-J CO transitions in Band 4, 5 and 7, while simultaneously observing [CI] and the dust continuum for free. As these same sources are used for measuring the faint-end of the CO LF, these data also provide key constraints on rho(H2) and continue to build the legacy value of the ASPECS Sample. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-07-01T00:00:00.000 |
| 79 | 2018.1.00945.S | 48 | Searching for Sintering-induced Rings in the Disk of LkCa 15 | Concentric and axisymmetric dust rings appear to be prevalent in protoplanetary disks. The sintering mechanism predicts that bright, optically thick rings should be formed at locations outside the snowlines of the major volatiles in disks, which may play a key role in creating the axisymmetric ring features. Recent ALMA N2H+ observations indicate that two disks, LkCa 15 and GM Aur, have very similar snowline structures. High angular resolution continuum observations of the GM Aur disk have already showed two bright dust rings that sit just outside the locations of each of the CO and N2 snowlines respectively, a double-ring system consistent with the sintering hypothesis. Here we propose to resolve the substructure of the LkCa 15 disk by imaging the dust continuum at 5 AU resolution to compare with the locations of snowlines determined in the disk. The presence of similar double-ring systems coincident with snowline locations in both LkCa 15 and GM Aur disks will provide unambiguous evidence of the aggregate sintering mechanism operating in the disks around young stars. | Disks around low-mass stars | Disks and planet formation | 2019-12-19T18:00:24.000 |
| 80 | 2019.1.01637.S | 5 | Revealing the Jupiter shaping Vega's planetary system through ALMA astrometry | Extrasolar Jupiter analogs at a few AU gravitationally dominate the dynamics of planetary systems, influencing the outcome of planet formation. They are most common around systems with planetesimal belts around massive A stars, where unfortunately the radial velocity (RV) technique is least sensitive. We here propose a multi-Cycle monitoring campaign of Vega to astrometrically detect the exo-Jupiter responsible for shaping the double-belt architecture of its planetary system. Astrometry is the only way to detect Jupiters at a few AU in the face-on Vega planetary system, and Vega is best suited for such an experiment with ALMA. With three short repetitions per Cycle, in 5 years we will be able to detect the stellar astrometric signature induced by any of the giant planets directly imaged in other planetary systems around massive stars with planetesimal belts. Through this project, we will demonstrate ALMA's unique capabilities for astrometric planet detection around the brightest, nearby massive stars avoided by Gaia. | Debris disks, Exo-planets | Disks and planet formation | 2022-11-25T02:48:33.000 |
| 81 | 2023.1.00594.S | 0 | Ice-cold gas in a frying cloud? The temperature of the N2H+ emitting dense gas near the NGC3603 starburst cluster | Feedback from massive stars on dense, star forming gas may significantly affect the resulting stellar population. Higher temperatures may allow for more massive cores to form before they proceed to collapse. As part of a larger effort to search for dense gas temperature variations due to feedback and any resulting differences in fragmentation we here propose to measure the temperature of an allegedly very cold gas component traced by APEX N2H+ observations in several dense clumps nearby the NGC3603 galactic young starburst cluster. H2CO measurements indicate temperatures as high as 50K for the clumps, too warm for N2H+ to survive. The detection of N2H+ in these seemingly warm cores may imply that there is an even colder component, shielded from the feedback, The proposed N2H+ temperature measurements will show whether the N2H+ emission arises in warm, dense gas heated by the cluster (as has been found in Orion by Teng & Hirano 2020), or whether indeed COLD dense gas may still exist in clumps subject to strong external heating. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-01-22T15:53:23.000 |
| 82 | 2016.2.00006.S | 265 | Recovering Extended Structures in Merger Remnants | Contrary to the classical scenario of galaxy merger in which an elliptical galaxy forms due to a major merger, recent studies argued that some fraction of the merger would reemerge as a disk galaxy by forming an extended gaseous disk. In order to check this scenario, we conducted a CO (1-0) survey on local merger remnants with the Cycle 0 ALMA 12m-array and found a high occurrence rate of molecular gas disks with various sizes. However, the ALMA data were taken using the 12m-array alone and they were clearly suffering from the missing flux problem, up to 57% in the worst case. Correctly quantifying the true size of the molecular disk and assessing its relation to the stellar size is the key to unambiguously define the type of galaxy the merger will evolve into. We thus propose follow-up CO (1-0) observations with ACA towards 14 merger remnants to accurately measure the extent and amount of molecular gas, by combining new ACA data with the Cycle 0 12m-array data. This study will allow us to accurately evaluate the frequency of the occurrence of extended gas disks in post-mergers, and offer stronger support to the scenario that merging events are the crossroads of galaxy evolution. | Merging and interacting galaxies | Galaxy evolution | 2018-08-21T19:44:54.000 |
| 83 | 2015.1.00942.S | 37 | Shut It Down: Probing Molecular Feedback in z~4.5 Dusty, Star-forming Galaxies | Above stellar masses of log(M*/Msun)~11, the abundance of galaxies drops exponentially, even out to z~4. These galaxies host little ongoing star formation, and appear to have been quickly and efficiently "quenched," but the process(es) by which this quenching occurs are poorly understood. Theoretical models invoke feedback from AGN and/or star formation to disrupt, expel, or heat the gas supply and prevent further star formation. Recent observations and circumstantial evidence suggests that the bulk of star formation in the earliest quiescent galaxies took place in dusty, star-forming galaxies (DSFGs). We propose to test models of feedback and the evolutionary connection between DSFGs and quiescent galaxies by spatially and spectrally resolving massive molecular outflows in six z~4.5 galaxies. Our observations will constrain the outflow geometry, mass loss rates, and feedback mechanism, allowing us to determine whether quenching is likely due to gas depletion or gas removal. These galaxies span a factor of 5x in star formation rate (SFR) and 20x in SFR surface density, giving a large dynamic range to constrain outflow scaling relations and extend local work to high-z. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-04-11T21:52:57.000 |
| 84 | 2019.1.01398.S | 10 | Does molecular gas follow the motion of ionized gas inside typical high-redshift star-forming galaxies? | To establish a complete picture of galaxy formation, one needs to understand how gas distributes and moves inside galaxies and the physical processes behind it. But this is not known for typical star-forming galaxies in the distant universe. To address this question, we propose spatially-resolved observation of the CO 2-1 emission line for one representative star-forming galaxy at z=1.0. We plan to determine the spatial distribution and kinematics of cold molecular gas. The results will be compared with deep archival H-alpha measurements which trace ionized gas, to determine whether molecular gas follows the distribution and motion of ionized gas. Such a comparison will help us determine which mechanisms, winds/outflows, mergers and/or gas accretions, have the dominant influence on the gas in our representative galaxy. The influence of each candidate is expected to be differentiable from observation, based on the physical argument that molecular gas and ionized gas have different densities and temperatures. | Galaxy structure & evolution | Galaxy evolution | 2022-10-28T05:25:08.000 |
| 85 | 2015.1.00423.S | 7 | A Search for Pyridine and Pyrimidine on TItan | We propose to search spectroscopically for the small cyclic molecules pyridine (C5H5N) and pyrimidine (C4H4N2) in Titan's atmosphere using ALMA Band 6. The presence of pyridine is inferred from the detection of the C5H5H+ ion by the Cassini mass spectrometer (INMS) in the ionosphere. Other species first detected by direct sampling of the ionosphere (C3H6, C2H5CN) have later been confirmed spectroscopically in the dense neutral atmosphere (Nixon et al, 2013; Cordiner et al. 2015). Benzene, the only presently confirmed ring molecule, has been detected in both ionosphere and stratosphere. The detection of pyridine would be a major discovery in astrochemistry, since no N-substituted rings have previously been detected in space. The closely related molecule pyrimidine has profound astrobiological significance, as it forms the backbone ring for two of the four nucleobases (thymine and cytosine). This project, uniquely possible with ALMA's capabilities in ~4 hr of time, has the potential for making a major advance in our understanding of planetary atmospheres and for the formation of prebiotic molecules in astronomical environments. | Solar system - Planetary atmospheres | Solar system | 2017-07-06T23:15:22.000 |
| 86 | 2015.1.00512.S | 178 | Testing the formation mechanism of sub-stellar objects in Lupus | Lupus 1 and 3 southern molecular clouds are excellent laboratories to study the formation processes of sub-stellar objects. Our group (SOLA consortium) has identified a set of pre- and proto-stellar candidates of substellar nature using 1.1mm ASTE/AzTEC maps and analyzing its SED using our optical to submillimeter database. We propose continuum observations at 1.3mm using 0.8" spatial resolution towards the most promising pre- and proto-brown dwarfs candidates found in Lupus 1 and 3. Our aims are to characterize the dust envelope/disk surrounding these sub-stellar objects, as well as measure the disk mass in the more evolved ones (Class II equivalent). ALMA observations of this sample have a potential to, for the first time, provide a general picture of how substellar objects form and evolve, from the equivalent to the pre-stellar cores to the Class II stage in the low mass regime of star formation. Our sample comprises 33 pre-stellar objects, 7 Class 0 and I objects, and 22 Class II objects. This proposal, requesting only 6.8hr time, will provide an important insight on the formation of brown dwarfs. | Low-mass star formation | ISM and star formation | 2017-05-11T19:54:21.000 |
| 87 | 2018.1.00242.S | 46 | Revealing the mechanism of massive star formation in NGC6822 | It is known that star complexes are often formed in massive giant molecular clouds (GMCs). In the other study we found that the massive star formation in W51, one of the most luminous star forming regions in the Galaxy, was triggered by cloud-cloud collision (CCC). In this proposal, we focus on Hubble V, which shows the most active star-formation in a nearby galaxy NGC6822. The star formation properties are similar between the two, although general properties of their parent galaxies are quite different. It is intriguing to resolve the GMC associated with Hubble V at a high spatial resolution of sub-pc, and investigate if the star formation was also triggered by CCC same as W51 or not. We propose to observe 12CO(2-1), 13CO(2-1), C18O(2-1), and H30alpha emission lines at a spatial resolution comparable with that in our study of W51, ~0.4 pc. We will apply our understandings and method used in the W51 GMC to reveal the internal structures of the GMC, and search the observational signature of CCC. The new ALMA data will allow us to make direct comparisons between W51 in the Galaxy and Hubble V in NGC6822, leading to a comprehensive understanding of massive star formation in GMCs. | Starbursts, star formation | Active galaxies | 2020-07-08T00:00:00.000 |
| 88 | 2017.1.00912.S | 227 | Protoplanetary Disks in the Hostile Environment of Carina | Our aim is to extend the work made by Mesa-Delgado et al. (2016) and image for the first time more circumstellar disks and compact molecular outflows associated with the dusty globules located in the Carina Nebula. From these dusty globules are emanating powerful HH objects traced by their H and [Fe II] emission revealed by HST/WFC3-IR observations. These observations will likely reveal the 1.3 mm continuum and molecular emission from more dusty protoplanetary disks that are exiting the HH objects. With these observations, we will be able to firmly reveal how the external photo-evaporation affects the dusty globules and disks in a large portion of the Carina Nebula and if the planetary formation is possible. | Low-mass star formation | ISM and star formation | 2019-03-01T14:36:11.000 |
| 89 | 2015.1.00650.S | 7 | The nature of the massive outflow in Centaurus A | Several massive outflows have been discovered in very luminous and active galaxies. None of these can be studied in much detail, owing to the great distances of the host galaxies. Only Centaurus A, a giant radio galaxy that is exceptionally close to us, provides an opportunity to do so. This has become relevant since the discovery of a slow, massive outflow along the much faster relativistic jets, seen in neutral and ionized atomic line emission. In order to investigate its origin and properties, we propose to image the core of Cen A with ALMA in the CO (4-3) an [CI] (1-0) lines at $1"$ resolution. In the core, a supermassive black hole is surrounded by a cool circumnuclear disk from which matter falls in towards a compact inner zone where much of it must be deflected into the newly discovered outflow. The images will reveal the physical and kinematical structure of the outflow from the Cen A center, in addition to that of the circumnuclear disk, the gas reservoir supplying both SMBH and outflow. We will analyse the data using our estensive database of observations at lower resolution and the radiative transfer models developed specifically for such purposes. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2017-08-22T15:15:36.000 |
| 90 | 2017.A.00026.S | 18 | Unveiling the ISM properties of a mature spectroscopically-confirmed lensed galaxy at z=9.1 | The formation and early evolution of the first galaxies remains an outstanding quest in modern astronomy. In ALMA Cycle 4, our team spectroscopically confirmed a z=9.1096 gravitationally-lensed galaxy via [OIII] 88 micron emission in Band 7. Concurrently, deep X-shooter observations revealed Lyman alpha emission blueshifted by 450 km/s, suggesting this object is located in a large ionized bubble. The most exciting aspect which merits urgent follow-up observations is the prominent Balmer discontinuity seen in this, the most distant known ALMA source, which indicates the bulk of its stars may have formed as early as redshift z=15. We thus propose to exploit the newly-available Band 5 to determine the strength of [CII] 158 micron emission, thereby determining the gas phase metallicity of this mature system as well as the systemic redshift for future ALMA studies of further diagnostic lines. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-06-26T15:55:10.000 |
| 91 | 2018.1.01123.S | 38 | Cold Gas Around Black Holes: Fueling and Feedback in Galaxy Mergers | We propose to obtain very long baseline observations of CO(2-1) to measure the distribution and kinematics of cold molecular gas in the central few hundred parsecs of two outflow host galaxies, IRAS F17207-0014 and IIIZw035. Our adaptive optics integral field spectroscopy has identified two key features within the nuclei of these galaxies: collimated warm molecular outflows and central dynamical masses 3-30 times larger than those predicted by black hole scaling relations. Only ALMA can provide the resolution-matched molecular gas observations needed to measure the temperature distributions and mass-loading factors of these confirmed nuclear outflows, a fundamental question regarding central engine feedback in galaxy evolution. The large central dynamical masses measured from our AO observations may be identifying a large mass of gas that will eventually fuel the black hole or be entrained in a molecular outflow. Our proposed observations will therefore either confirm some of the most extreme black hole scaling relation offsets or identify systems poised to undergo a massive central AGN accretion or starburst event. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2022-11-08T16:35:44.000 |
| 92 | 2023.1.00884.S | 0 | Cloud-Scale CO excitation drivers in nearby galaxies targeted with JWST | Understanding CO excitation conditions is increasingly essential, especially in the extragalactic context, where several different CO lines are used to trace the molecular gas. The CO(3-2)/(2-1) line ratio (R32) is easily accessible to ALMA and appears very sensitive to CO excitation but has not been studied much in other galaxies. The R32 studies that do exist have poor resolution and large calibration uncertainties. Here, we propose new high-quality CO(3-2) mapping of five strongly barred spiral galaxies that have high-resolution ALMA CO(2-1) and public Cycle 1 JWST mid-IR imaging that directly traces embedded star formation expected to drive excitation at high resolution. We will use these new maps to produce high S/N, <100-pc scale, well-calibrated R32 line ratio measurements. Then, we will correlate R32 variation to parameters such as the gas surface density, gas velocity dispersion, and heating by young stellar populations. This will provide some of the best measurements to date of how CO excitation varies across galaxies, how star formation may alter excitation conditions, and how this might affect CO-to-H2 conversion factor estimates using different CO transitions. | Spiral galaxies | Local Universe | 2025-06-07T14:56:16.000 |
| 93 | 2017.1.01223.S | 0 | Origins of Polarized Emission from Young Intermediate-Mass Protostellar Sources | While polarized dust emission from magnetically aligned dust grains have been confirmed as an excellent way to study the magnetic field direction on the scale of molecular clouds, cores, and dense envelopes, the origins of the polarized dust emission in the vicinity of young stars where you expected to see the dust growth, are not understood well. Three models (i) magnetic alignment, (ii) self-scattering, and (iii) radiation torque from the central star have been proposed for the grain alignment. Multi-wavelength observation is unique method allowing us to constrain the dust size and polarization emission mechanism. With ALMA Band 6 dust polarization observations, we have successfully spatially resolved polarization emissions and vectors toward an early Class 0 source with a size scale of 10AU. Based on the results, we propose the Band 3 polarization observations with the highest annular resolution possible (0.043 arcsec) toward this unique source. With the multi-wavelength dust polarization data, we aim to address which of the three grain alignment mechanisms is most consistent to explain the observed data. | Outflows, jets and ionized winds, Magellanic Clouds | ISM and star formation | 2019-01-04T05:04:11.000 |
| 94 | 2016.1.00735.S | 89 | Spatially-resolved star formation at high-z; are AGN host galaxies special? | Understanding the processes that drive the most luminous AGN and star formation activity in the Universe remains a significant challenge in observational cosmology. Towards this, we aim to compare the sizes and distribution of the rest-frame far-infrared emission at ~1kpc resolution between luminosity and redshift matched samples of non-AGN and AGN high redshift (z=1.5-5) star-forming galaxies. Here we propose to observe 21 sources, which combined with our previous observations create a sample of 17 AGN and 17 non AGN host galaxies that uniformaly cover an order of magnitude in far infrared luminosity (L(IR)~10^12-10^13 Lsol). We will measure the sizes and morphologies of the obscured star formation regions and measure star formation rate surface densities. We will search for systematic differences between the two populations, providing unique insight into how AGN activity and star formation are connected on ~1kpc scales in high-redshift galaxies. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-09-05T16:07:13.000 |
| 95 | 2019.1.00299.S | 14 | Toward Understanding the Misalignment of Outflow and Jet from Protostars: Observation of the Warped Disk | The goal of this proposal is to understand the formation of the disk associated with the outflow and jet driving during the main accretion phase. For this purpose, we propose the observation of the disk/envelope and molecular outflow/jet in 5 line emissions: C18O J = 3-2, CS J = 7-6, HCO+ J = 5-6, CO J = 3-2 and SiO J = 8-7 and 0.9 mm continuum. Our target is the Class 0 object, MMS 5, which shows misalignment outflows and jets direction, at the Orion Molecular Cloud 3 (OMC-3). MMS 5/OMC-3 is the only object of detecting both outflow and jet, and misalignment of these direction with ~1,000 year after protostar formation or outflow/jet driving. Since the MMS 5/OMC-3 is extremely young, the only case is that the size of the jet is shorter than that of outflow. Our high-resolution and higher excitation observation results will reveal the warped disk structure, Keplarian rotation disk and inner jet structure within 20 au scale. Moreover, requested observed lines can trace infalling envelope and disk, and the jet close to the central source. Therefore, our proposal is important to understand the mass ejection, mass accretion and disk formation mechanism in protostar forming early phase. | Outflows, jets and ionized winds, Intermediate-mass star formation | ISM and star formation | 2021-01-23T15:29:18.000 |
| 96 | 2016.1.00119.S | 27 | Probing the distribution of H2CO and warm SO2 toward the O-rich CSE of IKTau | We carried out a mm-wavelenght survey with the IRAM-30m telescope toward IKTau, and we detected H2CO and warm SO2. The linewidths of SO2 indicate that they are formed close to the stellar surface. Thermodynamical equilibrium (TE) models in O-rich stars predict that all the C should be locked up into CO and they do not predict high abundances of other C-bearing molecules (e.g. HCN or CH4). Concerning SO2, TE models predict abundances 2 orders of magnitude lower than what we derived from our observations, even when these models invoke the effect of dust and shocks. Thus, chemical kinetic models have to introduce ad hoc abundances of parent molecules and none of the chemical models proposed explained how H2CO is formed or how SO2 can be found close to the stellar surface with such high abundances in O-rich stars. High spatial resolution observations with ALMA of H2CO and SO2 emission toward IKTau offer a new approach that may shed light on the problem of the formation of C-bearing molecules in O-rich CSEs, and discover how SO2 is distributed and formed in the inner regions of the CSE with abundances currently unexplained by chemical models. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2019-02-23T01:45:08.000 |
| 97 | 2013.1.00634.S | 36 | Does the Dense Gas Fraction Control SF/H2? | We propose to test the hypothesis that the dense gas fraction regulates the star formation rate (SFR) by using ALMA to make resolved “dense gas maps” of a carefully selected sample of galaxies. Several theories identify the fraction of dense molecular gas as the key factor that sets the SFR per unit H2. We will test this by correlating observable tracers of dense gas fraction – e.g., HCN/13CO – with SFR/H2 across the central 6 kpc of four nearby galaxies. Our targets capture both the spread in SFR/H2 among local galaxies and the contrast between nuclear starbursts and more quiescent disk star formation. They are also close enough we achieve both high brightness sensitivity and good physical resolution. They also have the data needed estimate the SFR and key galactic and ISM properties; only information on gas density is missing. ALMA alone can image high critical density (HCN, HCO+, CS) and optically thinner (13CO, C18O) tracers in normal galaxies at high resolution. With such data for a meaningful sample, we will build the next major benchmark for theories of star formation in galaxies, testing the role of dense gas in star formation and the conditions for dense gas formation. | Spiral galaxies, Surveys of galaxies | Local Universe | 2016-04-10T18:57:40.000 |
| 98 | 2018.1.00489.S | 8156 | An ALMA survey of 2000 bright SMGs | We propose an efficient ALMA continuum survey of 2100 bright SMGs selected from the H-ATLAS survey over 100 sq deg for being brighter than 45mJy in the SPIRE 500um band (no further selection is applied). This flux density limit implies that, whichever redshift, all our sources would have been detected down to the depth of classical extragalactic submm surveyes if very wide submm observations over 100 sq deg would have been carried out. Therefore, all our sources are truly SMGs. The fields, GAMA12 and GAMA15, have been chosen for being equatorial and having deep optical and near-IR imaging. The observations will allow us to cover a number of science goals, including: (1) the unexplored bright end of the submm number counts to constrain galaxy formation and evolution models; (2) a cosmographic study of lensed systems to improve the determination of cosmological parameters; (3) selecting extremely bright (unlensed) HyLIRGs; (4) isolate the most luminous starbursts in the early Universe; or (5) Investigate the properties of the bright SMG population. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2020-08-30T13:22:31.000 |
| 99 | 2015.1.01597.S | 3 | Measuring Velocity Structure of MHD Wind from a Protoplanetary Disk | We propose to observe line transitions of CI, CN and 13CO at bands 7 and 8 with high velocity resolution and high sensitivity in order to measure velocity structure of the MHD wind from a protoplanetary disk around TW Hya. Recent MHD simulations suggest that angular momentum transfer and mass accretion in the disk surface will be induced by magnetocentrifugal wind rather than magnetorotational instability. Our observations of a disk wind will give us information on mass accretion mechanisms, which is essential to understand gas dispersal from the disk and then planet formation processes. The wind velocity is not easy to measure since it is small compared with the Keplerian rotation velocity. Here we propose to detect the disk wind velocity, using PDR species (CI and CN) as disk wind tracers and 13CO as a tracer of Keplerian rotation. The difference in the maps of intensity weighted velocity field between the lines give us clear evidence of the disk wind. In addition, the difference in the maps of intensity weighted velocity dispersion will show the radial distribution of wind velocity and give us information of how angular momentum transfer is controlled in the disk surface. | Disks around low-mass stars | Disks and planet formation | 2018-02-10T04:54:02.000 |
| 100 | 2019.1.01220.S | 9 | Resolving the planetesimal belts of three stirred debris discs | Debris discs are belts of dusty material left over from planet(esimal) formation processes in primordial proto-planetary discs. Spatially resolved observations at optical, infrared and millimetre wavelengths provide complementary information on the dust properties (size distribution, scattering, albedo) and disc architecture (radius, width, orientation), critical to determine both the disc structure and dust properties through imaging and radiative transfer modelling. We have proposed Hubble observations of 11 debris discs potentially observable in scattered light (~ 1/3 of all Hubble-detected scattered light discs). Here we propose ALMA Band 6 observations of the 3 targets in the Hubble proposal for which ALMA archival data does not exist. These systems are young A- and F-type stars resolved at far-infrared wavelengths by Herschel and exhibit evidence of stirring due to the large disc radii. We will resolve the discs belts to determine their radii and widths, search for CO emission from exocomet collisions, and combine the ALMA, Herschel, and Hubble data in a multi-wavelength comparative study of the disc structures in scattered light and infrared/millimetre. | Debris disks | Disks and planet formation | 2021-07-07T06:03:43.000 |
| 101 | 2021.1.00345.S | 9 | Can the observations probe the theory ? : the Case of Magnetic launching in Pre-Planetary nebulae | We propose to tackle the long standing issue regarding the role of magnetic field in the shaping of evolved intermediate mass stars. Indeed, several recent theoretical models (MHD) have shown that magnetic fields are important actors in the production of particular morphological structures (knots/protrusons) as well as in participating in the launch of the outflows/jets leading to bipolar or multipolar nebulae. We therefore aim at observing a set of proto Planetary Nebulae in order to trace their magnetic field distribution via dust continuum polarization studies close to their central engine. The results will be compared to the models and we expect to better undertand the departure from spherical symmetry that occurs in the late stages of stellar evolution. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-08-04T14:59:47.000 |
| 102 | 2017.1.01492.S | 98 | Many-in-one: ALMA undetected single-dish submm sources - Extreme multiplicity in action? | During Cycle 3 and 4 we have obtained ALMA Band 7 observations of over 700 SCUBA-2 detected submm sources (S850 > 3.5mJy) with the majority of the brightest sources being comprised of a blend of multiple SMGs confirming previous survey results. However 15% of single-dish sources are blank with no detected SMGs S870>1.2mJy suggesting that these submm sources display exceptional multiplicity, being comprised of several faint SMGs. Therefore we are proposing to re-observe 10 of the brightest 'blank' ALMA maps to an increased depth of 0.1mJy (3x deeper) to determine the true level of multiplicity of these sources. | Surveys of galaxies | Galaxy evolution | 2019-09-03T10:36:57.000 |
| 103 | 2013.1.00907.S | 2 | Measuring the molecular gas mass of a high redshift galaxy with HD | We plan to observe the ground state transition of deuterated molecular hydrogen (HD) toward a dusty galaxy at z = 5.656. The line is predicted to be detectable in emission. These observations will provide the total amount of HD molecules and, through the HD/H2 abundance ratio given by the cosmic abundance of deuterium, the total molecular gas mass, independent on uncertainties plaguing other standard methods. If successful, this data will open a new way to measure masses of molecular gas in the Universe and it can be used to calibrate the CO to H2 conversion factor and dust emission methods. | Starburst galaxies | Active galaxies | 2016-06-20T00:18:45.000 |
| 104 | 2024.1.00511.S | 0 | Observing dust polarization in the strongly magnetized nuclear star forming ring of NGC1097 | This proposal aims at observing dust polarization in the prototypical galaxy: NGC1097. NGC 1097 has a prominent nuclear ring. The magnetic field in this region of intense star formation is the strongest ever detected in full polarization radio-continuum observations. Recent FIR dust polarization observations have been obtained with SOFIA complementing the radio information. Both FIR and radio polarization show a high degree of polarization in the two contact points between the inner-bar and the starburst ring, possibly due to gas flow from the bar to the ring. By observing dust polarization at scales of giant molecular associations in the ring, and in particular in the two contact regions, we aim to gain a better understanding of the magnetic field and its relation with star formation. NGC1097 is a unique extragalactic target to take advantage of ALMA's unprecedented capabilities in full polarization. We are confident that our goals can be achieved, since ALMA's high accuracty in polarization has been proven in the last years, there are in particular archival data of a nearby galaxy NGC253 where polarization fractions as low as 1% have been measured with 0.1% accuracy | Giant Molecular Clouds (GMC) properties | ISM and star formation | 3000-01-01T00:00:00.000 |
| 105 | 2017.1.00300.S | 15 | A hybriod scenario for extreme starbursts in high-redshift SMGs | We propose 0.06arcsec (400pc)-resolution observations of CO(4-3) line in the brightest, unlensed SMG at z=4, AzTEC-1. The goal is to reveal the physical mechanisms of extreme starbursts in massive galaxies at high-redshift. In ALMA cycle-3, our high-resolution (150-500pc) 860um dust continnum observations reveal that AzTEC-1 hosts a nuclear starburst with an extremely high far-infrared luminosity surface density and have several clumps on the underlying extended structure. These findings suggest a hybrid scenario, that is a late-stage merging starburst plus an extended, gravitationally unstable disk, to explain the physical properteis of AzTEC-1. In the proposed CO observations, we will study the kinematics in the central region and the outer extended structure to verify the hybrid scenario. The results can be directly compared to central regions in local LIRGs/ULIRGs at same spatial resolution in physical scale. Even for one target, this pioneering work about the new scenario will have a strong impact on galaxy formation models. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-08-29T00:00:00.000 |
| 106 | 2016.A.00018.S | 14 | A detailed image of the first merger | In ALMA cycle 3 we snapshot-surveyed [CII] and far-IR emission in a large sample of QSOs at z>6. Unexpectedly, 4 of the 27 observed QSOs showed [CII]-bright companion galaxies in their proximity, pinpointing the presence of first galactic overdensities in the Universe. In particular, the companion galaxy of the QSO PJ308-21 at z=6.23 exibits a large velocity gradient (>1000 km/s), and an elongated morphology (stretching over an impressive ~25 kpc), highly suggestive of an on-going galaxy merger with the QSO host galaxy. In terms of cosmic time (820 Myr after the Big Bang), this is the earliest merger of gas-rich galaxies known to date, and offers the outstanding opportunity to study the first phases of massive galaxy growth. In this 1.9 hr DDT request, we propose to collect deep, high-resolution images of the [CII]-emitting gas and of the dust in this exceptional system. This will expose the details of the gas morphology and dynamics. These observations will provide a critical complement to our on-going Cycle 4 program that maps the other 3 QSOs with companions at the same resolution as requested here. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2017-11-16T23:45:22.000 |
| 107 | 2019.2.00067.S | 10 | A Search for Shocks in the Rare Massive Merging Cluster SPT-CLJ2031-4037 | Galaxy cluster mergers are important and rare laboratories for understanding the properties of dark matter. ALMA and the ACA have been used to detected, image, and characterize shocks in a few remarkable merging galaxy clusters: El Gordo, RXJ1347.5-1145, and the Bullet Cluster. Notably, these observations required similar or shorter obserations that X-ray observations providing comparable constraints on the shock properties. Further, the constraints driven by the ACA data, rather than the ALMA 12-meter data. We propose here ACA observations of a binary merger found (but not discovered) in South Pole Telescope (SPT) survey, which exploited the Sunyaev-Zeldovich effect to discover hundreds of clusters from a region about 1/16 the full sky. These observations will provide a complementary view to recently obtained Chandra observations, unambiguously determining where the shocks are located and what their Mach numbers are. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2022-10-31T18:14:38.000 |
| 108 | 2015.1.01287.S | 39 | Particle growth in disks across the substellar limit | Circumstellar disks are central for the formation of planets. Their ability to form planets depends on their mass and ability to grow dust into larger particles. With the ALMA sensivity and an ideal sample of 12 young, low mass objects, we propose to get 3mm maps to measure the dust properties of protoplanetary disks over the stellar/substellar transition. By targeting objects already detected at 885um in our Cy1 ALMA program, each too faint for follow-up with any other facility, we maximize the detection probability and the SED coverage, important for the characterization of disk properties. ALMA is essential to move from a small number of detections (brightest low mass objects) to a comprehensive understanding of brown dwarf disk properties. Currently, only 3 Taurus low mass objects (spty. M4-M8) have measured spectral slopes. With the proposed ALMA observations, we will observe four times this number and enable an investigation of the more typical disks. By targeting the lowest mass members of the well known Taurus region, we will efficiently complete a comprehensive population study across the full mass spectrum by combining the proposed ALMA study with existing measurements. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2017-11-03T05:27:11.000 |
| 109 | 2017.1.00303.S | 0 | Confirmation of a sample of pre- and proto-substellar objects in Lupus molecular clouds | The nearby southern molecular clouds Lupus I and III are ideal laboratories for studying the formation processes of sub-stellar objects. Our group (the SOLA consortium) has identified a set of pre- and proto-substellar candidates using ALMA Cycle 3 data at 1.3 mm. We propose observations in Band 7 and Band 3 in continuum and spectral lines in an attempt to confirm the real nature of these candidates as pre- and proto-brown dwarfs and clarify their apparent association with the Lupus clouds. The proposed observations will allow us to measure accurately the mass of the dust envelopes and dust disks surrounding these objects, to assess their dynamical state (e.g. transient versus self-gravitating condensations), and reveal the presence of large dust particle (millimetre to centimetre sizes). ALMA observations of this sample have the potential for the first time to provide a general picture of how substellar objects form and evolve, from pre-brown dwarf cores to proto-brown dwarfs. This proposal, requesting 6.5 hours time, will provide an important insight on the formation of brown dwarfs. | Low-mass star formation | ISM and star formation | 2019-11-22T16:26:32.000 |
| 110 | 2012.1.00719.S | 0 | Tracing the re-ionization epoch through millimeter spectroscopy v3 | We propose to use ALMA to detect and map the [CII]158um line in a complete sample of the most distant star forming galaxies observable from ALMA, including all objects with high-S/N spectroscopic detection of the Lyalpha line at z>6.8. These galaxies are distributed over the epoch of re-ionization of the Universe The detection of the [CII] line in these galaxies will open new uncharted regions of the Universe to the ALMA observations. It will address fundamental questions related to the physical nature of these galaxies and will test recent evidence suggesting that the Universe was still partly neutral at z~7. In particular, the goal of these observations are: 1) to determine the neutral fraction of the IGM at z~7, by comparing the redshift of the [CII] with the Lyalpha profile, that is absorbed by the neutral IGM; 2) to measure the star formation rate independently of the UV luminosity, which is very sensitive to dust corrections; 3) to constrain the metallicity of these primeval galaxies | Lyman Break Galaxies (LBG) | Galaxy evolution | 2014-11-21T10:19:38.000 |
| 111 | 2018.1.01787.S | 59 | Searching for high-mass pre-stellar cores in an exceptional nursery | The W43-MM1 ridge that is an extreme cloud in terms of concentration and star formation activity, is a case-study to confront models of high-mass star formation. An ALMA Cycle 2 1 mm mosaic of W43-MM1 revealed a rich protocluster of 131 cores, among which 18 able to form a high-mass star. The study of SiO shocks tracing protostellar outflows and chemical complexity associated with protostellar heating led to the preliminary identification of 11 high-mass protostars, 1 high-mass pre-stellar core candidate and six core whose nature remains undefined. The outflow study is however blurred by the richness of the protocluster; all identified outflows are notably confused by neighbor outflows. Hot core investigation is itself limited by the line strength of heated gas strongly diluted within the massive cold envelope of cores. We propose to disentangle and definitively determine the evolutionary status of 18 high-mass cores identified in Cycle 2. We will then give constraints on the most plausible scenario of high-mass star formation using the complete sample of high-mass cores in W43-MM1, their measured turbulence levels and gas mass inflows. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-02-11T10:57:37.000 |
| 112 | 2017.1.00124.S | 3 | Constraining the grain growth with polarimetric imaging | We propose to perform double-band continuum and polarimetric imagings of a protoplanetary disk around a T Tauri star AS209 to measure the radial dependence of the grain size. The polarization on protoplanetary disks is thought to be due to the alignment of dust grains or self-scattering of the thermal dust emission. We perform double-band polarimetric imagings to extract the information of the scattering-induced polarization. The polarized emission should be bright enough to detect if the grain size is comparable to the wavelengths. At the same time we could also obtain the spatially resolved spectral index map because the emission is supposed to be optically thin at both wavelengths. Combining these two constraints on the grain size, we would obtain the grain size constraints at the midplane of the disk from both absorption and scattering opacities, which would be strong constraints on the dust coagulation process. | Disks around low-mass stars | Disks and planet formation | 2019-08-02T22:33:55.000 |
| 113 | 2011.0.00724.S | 0 | The origin of transitional disks: grain growth or dynamical clearing by planets? | Most young, low mass stars are surrounded by optically thick accretion disks. A small fraction of these stars show a remarkable depletion of dust in the inner disk regions. These so-called ``transition disks'' are thought to represent a brief, but extremely important, evolutionary phase between young, optically thick protoplanetary disks and old, optically thin debris disks. A number of mechanisms have been proposed to deplete the inner regions of transition disks, including grain growth, photo-evaporation by the central star, and dynamical clearing by a recently formed planet. Observationally, distinguishing between these mechanisms has been difficult up to now. In this proposal, we request time with ALMA to image a subset of transition disks with large inner holes, large disk masses, and high accretion rates, that likely originate by either grain growth or dynamical clearing by a planetary object. ALMA's exquisite sensitivity and high angular resolution, already available in Early Science, can resolve the inner disk and detect trace amounts of dust in the depleted regions. Analysis of the visibility data will reveal if the inner edge of the disk is sharply truncated (favoring dynamical sculpting by a planet), or if the inner edge varies smoothly with radius (favoring accelerated grain growth in the inner disk). | Disks around low-mass stars | Disks and planet formation | 2013-10-11T19:41:00.000 |
| 114 | 2016.1.00362.S | 17 | A Deep Synoptic Observation for Fragmentation and Star-formation in an OB Cluster-Forming Molecular Clump | Our ALMA cycle-1 observations towards the ~1 pc scale, ~5000 M_sun OB cluster-forming molecular clump G33.92+0.01 A have resolved the intriguing morphology of gas spiral arms embedded with localized dense molecular cores, which are orbiting the two ~200 M_sun centralized massive cores. Here we propose to perform the follow-up band 6, 0".09 resolution (640 AU) observations. The proposed angular resolution and sensitivity can marginally detect the gas rich (~0.05 M_sun) protoplanetary disks. Combining the proposed observations with the cycle-1 data can diagnose the fragmentation of dense cores, and address how the gas accretion flows converge from parsec scale down to individual of the YSOs. Finally, we will based on the CH3CH J=12-11 K-ladders covered by these observations, and the high-resolution dust image, to diagnose the Toomre stability of the highest mass (~200 M_sun) core G33.92+0.11 A1. These results will provide important clarification for the highest mass end of the core mass function in OB cluster-forming region, and will distinguish whether high-mass star forms via a single collapsing massive core, or forms via competitive accretion of many lower-mass progenitors. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-09-20T00:00:00.000 |
| 115 | 2018.1.01194.S | 48 | The HH 24 Jets and their Multiple Driving Sources | We propose to study the quintessential small multiple protostellar system (SSV 63), which drives a group of 5 jets (HH 24) in the Orion B cloud, including a perfectly collimated bipolar jet. Most, and possibly all, stars are born in such small systems, which are unstable and decay into the singles, binaries, triples etc found in the field. The chaotic motions of the members in a cloud core cause frequent close flybys that lead to truncation of disks. High-resolution observations of 12CO, 13CO, C18O and continuum will investigate the current structure of the birth environment of the sextuple system, determine the variation in circumstellar environment of the individual stars, establish the sizes and masses of the circumstellar disks, measure the structure and kinematics of the gas entrained by the jets, provide accurate stellar positions for future proper motion measurements, clarify the structure, energy and momentum of the outflowing gas, and allow a search for close binary companions. In their totality, these observations will provide the first detailed insight into the nature of a small compact stellar system, which may represent a typical birth environment of low mass stars. | Outflows, jets and ionized winds | ISM and star formation | 2020-08-08T01:06:13.000 |
| 116 | 2021.1.00932.S | 9 | Dust and Star formation in the Hosts of Quasar Jets Caught Switching On | We propose an ALMA Band 7 imaging study of the rest-frame FIR emission of a unique sample of quasars that were recently caught launching newborn jets by the Very Large Array Sky Survey (VLASS). The targets are powerful quasars that have transitioned from radio-quiet to radio-loud in the past 10-20 years. Multi-wavelength follow-up observations in the radio and X-ray probing the jet and accretion properties are underway, but the properties of the host galaxies remain unknown. Our main goal is to investigate the interstellar medium (ISM) masses/morphologies and constrain the star formation rates (SFRs) of the hosts of quasars with newborn jets. This study will be the first to explore the dust and SF properties of quasars selected in the radio time domain as candidate newborn jets. We require the ALMA 12m-array, and emphasize that it is the only instrument in the world capable of resolving the 870 micron emission on kpc scales. Our proposed observations will ultimately pave the way for continued studies of jets in their youth as VLASS progresses over the next few years and catches more jets switching on. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-05-12T16:34:21.000 |
| 117 | 2013.1.00233.S | 2 | Disk kinematics and angular momentum distribution in Class I sources | We propose to resolve the disks around two Class I protostars, L1489 IRS (Taurus) and IRS43 ($\rho$ Ophiuchus) in order to map the gas kinematics as a function of disk radius, investigate the distribution of angular momentum in the disks, and learn about accretion processes and possible disk sub-structure and geometry by comparing observations to magnetohydrodynamical simulations of star formation. With this project we want to address the following questions (1) the dynamical structure of protoplanetary disks: how is material transported through the disk? Are Class I disks spreading or contracting? (2) The disk geometry: what is the shape of Class I protoplanetary disks? Are they flat and circular or are the warped and elongated? How does the shape relate to the angular momentum distribution? (3) The initial conditions for planet formation: are there evidence of local gas density enhancements in the disks? What are the turbulent velocities as function of disk radius? | Low-mass star formation | ISM and star formation | 2016-09-05T13:34:26.000 |
| 118 | 2021.1.00505.S | 5 | High-Resolution [CII] Observations of the Highest-Redshift Unlensed DSFG at z=5.85 | We propose for high-resolution (0.05'') [CII] and dust continuum imaging of the highest-redshift unlensed dusty star-forming galaxy (DSFG) system, MAMBO-9, at z=5.85. The fact that it is not a strong gravitational lens substantially helps the interpretation of its physical characteristics, with an unobstructed view at all wavelengths. Our goals are to: 1) Measure the [CII] kinematic structure of the MAMBO-9 system on a 300pc (0.05'') scale allowing a dynamical mass estimate for both galaxies in the system (which are seperated by 6kpc), 2) infer whether or not gravitational interaction between the two galaxies has significantly disturbed the morphological structure (thus driving the system's star formation), or if its gas is rotating in undisturbed disks, 3) Compare the spatially-resolved [CII] luminosity, FIR luminosity, and stellar mass distribution (via Cycle 1 JWST imaging) to directly map dust atteunuation and total SFR. With so few examples of extremely massive galaxies <1Gyr after the Big Bang (all others at this epoch are lensed), this detailed kinematic view of the MAMBO-9 system gives critical insight into the formation of the Universe's first massive galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2022-11-08T15:05:22.000 |
| 119 | 2017.1.00594.S | 10 | Probing non-uniform dust production rate in a young debris disk | Debris disks are the natural by-products of the star and planet formation processes. They consist of small dust grains released in a collisional cascade from larger planetesimals. From an observational point of view, we know very little about this process that is producing significant amount of small dust grains. Currently, the best way to study the grain size distribution is to constrain the spectral slope at millimeter wavelengths. We propose here a pilot study to derive a spatially resolved map of the slope of the grain size distribution in the young debris disk around HD181327. This disk has been spatially resolved on multiple occasions, with several instruments, and we think it is the best candidate for such a pioneering study. Based on HST observations, there are hints that a massive collision of planetesimals took place on one side of the disk, which should locally increase the dust production rate. We propose Band 3 observations to supplement exisitng archival Band 6 observations and constrain the collisional activity in the 23 Myr old debris disk. | Debris disks | Disks and planet formation | 2021-01-18T21:03:56.000 |
| 120 | 2019.1.00517.S | 5 | Mapping the Envelope-Disk Transition around a Massive Protostar | If massive stars form in a similar way as low-mass stars, a relatively ordered transition from an infalling/rotating envelope to a Keplerian disk is expected. Such a transition, similar to the case in low-mass star formation, should be seen in changes of both gas kinematics and chemical conditions. We propose ALMA Band 6 observations toward the massive protostar G339.88-1.26, a Keplerian disk candidate discovered in our previous ALMA project. We aim to carry out high-resolution mapping of the disk, inner envelope and transition region, as well as the base of the jet, with selected groups of molecules: SiO/NaCl to trace the disk (or disk surface), SO/SO2 to trace the shocked transition region and/or the outer part of the disk, CH3OH/H2CO to trace the envelope, CH3CN to trace the envelope and/or disk, and H2O/HDO to trace the transition region. Such observations will allow us to characterize the angular momentum transfer from the envelope to the disk and outflow, and constrain the disk properties in massive star formation. This study can potentially be developed into a general diagnostic tool for future searches for Keplerian disks around massive protostars. | High-mass star formation | ISM and star formation | 2023-09-12T18:18:59.000 |
| 121 | 2016.1.00501.S | 18 | Observing Cosmic Ray Acceleration using ALMA in a Strongly Interacting Supernova 2014C | Cosmic Ray acceleration is an unsolved problem in astrophysics and the physical parameters associated with the process are largely unknown. A supernova (SN) shockwave that is interacting with the dense surroundings will naturally accelerate protons to very high energies, which may undergo collisions and produce secondary electrons through cascade of particles. Theoretically we have shown that this effect should be observable, most prominently in the ALMA bands. Observationally we have also uncovered SN 2014C which is strongly interacting with a dense shell in the surroundings. We show that SN 2014C is the most suitable candidate to determine the cosmic ray acceleration efficiency in young SNe for the first time. For this purpose we propose ALMA band-6 observations of SN 2014C. Now that the SN emission has faded below the sensitivity of all other telescopes operating in the mm-wavebands, ALMA is the only telescope capable of carrying out these observations. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2018-09-08T04:45:32.000 |
| 122 | 2013.1.01195.S | 8 | Unveiling the central 1000 AU of a pre-stellar core | Pre-stellar cores (PSCs) represent the initial conditions for the process of star and planet formation. Although their overall structure is well known, their central few thousand AU are completely unexplored. The best tracers of regions with densities larger than 10^6 cm-3 (and temperatures around 7 K) are deuterated species. Because of its compact emission and brightness, we show that N2D+(3-2), observable with ALMA in Band 6, is the ideal tracer. ALMA Cycle 2 offers the first and unique opportunity to peer into the PSC central regions and study the birthplace of stars and protoplanetary disks at size scales of a few hundred AU. These observations will test recent models of the dynamical evolution of pre-stellar cores and the propagation of cosmic rays within them. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-02-16T13:11:36.000 |
| 123 | 2018.1.00429.S | 73 | The ISM conditions of UV-selected galaxies in the Epoch of Reionization | We propose Band 8 observations to measure [OIII]88mum in two z=6.8 UV-selected galaxies, recently spectroscopically confirmed with robust detections of [CII] using ALMA. Unlike z~7 Lyman-alpha emitting galaxies that were previously observed with ALMA, these two sources show high [CII] luminosities. The proposed observations of [OIII], a tracer of low-density, highly ionized gas, will elucidate the physical conditions in the interstellar medium of these sources. Using these observations, we can gain true insight into whether these galaxies contribute to cosmic reionization, by measuring the [OIII]/[CII] line luminosity ratio. We will test if high [OIII]/[CII] ratios are present in these galaxies similar to local dwarf galaxies, which require `leaking' ionizing photons from HII regions out into the diffuse ISM. We will furthermore put tight constraints on the dust masses of these sources, and, in combination with ongoing Cycle 5 observations on one of these sources, constrain the dust temperature in a `normal' star-forming galaxy in the Epoch of Reionzation. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-06-25T16:28:40.000 |
| 124 | 2017.1.01167.S | 200 | ALMA CHARACTERIZATION OF T TAURI DISKS | Understanding planet formation and the origin of the Solar System is a foremost ALMA science driver which motivates intense observations of young circumstellar disks, most particularly around solar-mass stars. While today high-resolution studies focus on the largest and brightest disks around Herbig stars, we propose to carry out a uniform (43 uJy sensitivity at 1.3 mm), high-resolution (50 mas, C43-8) survey to characterise T Tauri disks -likely progenitors of solar-type planetary systems. This survey will collect continuum and 12CO emission maps for 14 optically visible T Tauri disks recently imaged at 50 mas resolution in polarised scattered light. We have designed this survey based on these scientific objectives: 1) probe for sub-structures common to larger disks such as spirals, dust traps and warps, and compare these (or lack thereof) with scattered light images at matching resolution; 2) characterise their sizes, masses and gas content; 3) probe for dust settling and radial migration and how the distribution of small grains, mm dust and gas compare to each other. The targets are grouped in three different age ranges, enabling an evolutionary study. | Disks around low-mass stars | Disks and planet formation | 2021-05-01T07:13:55.000 |
| 125 | 2017.1.01405.S | 20 | The dynamics of molecular gas in outflow shocks | Protostellar outflows play a crucial role in star formation. Outflowing material slams into the surrounding envelope at high velocity, and the subsequent shocks heat gas, sputter grains and drive chemistry. Outflows are common place in both low- and high-mass stars, suggesting that all stars go through a stage of mass loss during their youth. Despite this, it is still unclear how the bulk part of the mass in the outflow is entrained and accelerated. Tackling this problem requires a detailed understanding of the velocity field of the outflowing gas that goes beyond the standard measurement of the radial component. To extend the study of the outflow velocity field to the bulk part of the gas in the outflow, it is necessary to apply the proper motion technique to molecular line observations. We propose to observe the SiO 5-4 and CO 2-1 transitions in the outflow of Serpens SMM1b. Combining this with previous ALMA observations of the same species and transitions from at least 1 and 3 years ago will allow us to determine the complex dynamics of the shocked molecular gas in the outflow and constrain the true velocity field of the gas. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-06-19T09:36:18.000 |
| 126 | 2023.1.01106.S | 0 | An ALMA Band 1 and VLA survey to probe the solid reservoir of Lupus disks | The available dust reservoir in disks and its particle-size distribution are critical properties that impact the process of planet formation: dust is vital for the growth of planets and its size-distribution influences how grains growth and evolve. Thus, we need accurate constraints on the solid reservoir of disks. We propose a Joint ALMA-VLA program to observe most Class II disks in the Lupus region: to accurately constrain their solid reservoir in ALMA B1 at 8mm, and concurrently constrain the non-dust emission that contaminates B1 data, with VLA in U and X bands (2 and 3cm). We focus in Lupus as this region is one of the best studied, with available stellar properties and ALMA B7, B6, B3 observations. We define an unbiased sensitivity-limited sample of disks that encompass the full range of stellar masses in Lupus, complete for stellar masses above 0.6Msun. In this proposal, we show that ALMA B1 observations are crucial to probe the solid reservoir, as emission is more optically thin than existing B3 and B6 data and directly probes disk dust properties. We also demonstrate the need for VLA data, to constrain any possible contamination from non-dust emission in B1 observations. | Disks around low-mass stars | Disks and planet formation | 2025-07-03T18:42:15.000 |
| 127 | 2015.1.00039.S | 540 | A Redshift Survey of ALMA identified Sub-mm Galaxies at z>4 | We propose to search for the redshifted [C II]157.7um emission in a sample of 21 ALMA-identified SMGs in the Extended Chandra Deep Field South from the ALESS survey. These SMGs have photometric redshifts of z>4 and all are "red-peakers" with SPIRE 500/350>1 colours. We will use two band 7 spectral scans, f=335-365GHz and f=280-310GHz to cover the redshift range z=4.23-4.7 and z-5.16-5.82 respectively. Our primary science goals are to: i) search for the [CII] emission in order to measure spectroscopic redshifts for these SMGs and so measure their bolometric luminosities and hence the contribution of z>4 SMGs to the comoving star formation density at this epoch ii) derive the bright end of the CII luminosity function at z=4 and test how this compares to z=0 and z=2. iii) measure the ratio of CII/FIR in a well selected sample of high-z ULIRGs to test whether the "CII" deficit is ubiquitous at high-redshift. iv) search for signs of extended CII emission in the observations to place constraintynamical masses which can be compared to gas and stellar mass estimates. The total time request for this program is 4.11 hours. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-01-19T10:36:02.000 |
| 128 | 2018.1.00612.S | 86 | Core mass function in metal-poor environments | Past studies of dense core suggest that the slope of the core mass function (CMF) and stellar initial mass function (IMF) are consistent, suggensing that the origin of the stellar IMF is directly linked to the origin of dense cores. However, dense cores have been only studied in the inner part of the Galactic plane, which has similar metallicity to that of the solar neighborhood. We proposed C18O and dust continuum mapping (1.0 arcmin × 1.7 arcmin: 3.7 pc × 6.3 pc) observation of a massive star forming molecular cloud (mass ~ 10^4 Msun, density > 10^4 cm^-3) in the outer Galaxy, which has a metallicity that is about only 20 % of the solar neighborhood. Using ALMA's high sensitivity observation with high angular resolution of 1.5" (0.09 pc), we will be able to estimate the CMF in metal-poor enviromnents for the first time. Our previous studies suggest that the slope of the stellar IMF is not sensitive to environmental conditions (universal IMF), and therefore, the CMF is also expected to be universal. Thus, we will verify "whether the CMF in metal-poor environment is universal or not" by comparing the CMF in the outer Galaxy with that in the inner part of the Galactic plane. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-12-24T05:33:10.000 |
| 129 | 2015.1.01023.S | 38 | High-Resolution Mapping of Titan's Atmospheric Composition, Dynamics and Temperature Near Southern Winter Solstice in Synergy with Cassini | We propose to conduct a detailed characterization of the thermal, chemical, and dynamical state of Titan's atmosphere near southern winter solstice. Using three Band 7 tunings at 0.14" resolution we propose to: * determine vertical and latitudinal distributions of all known compounds detected at submm wavelengths * constrain overall dynamics using distributions of trace species while directly measuring zonal+meridional wind components from 300 to 900 km altitude * determine thermospheric temperatures at 600-900 km altitude using HCN hyperfine components and independently using CO and HC3N * determine precise isotopic ratios in CO, HCN and other nitriles * investigate changes occurring in the south polar region, including dramatic enrichments in many constituents and potential detection of new molecules, isomers, and isotopologues. These observations will come towards the end of the Cassini Solstice Mission and will provide important and unique cross-calibration checks between Cassini and ALMA measurements. Ultimately this will allow ALMA to expand, improve upon, and extend the rich legacy of Titan atmospheric studies through an entire Titan year. | Solar system - Planetary atmospheres | Solar system | 2018-04-11T00:00:00.000 |
| 130 | 2022.1.01654.S | 38 | Untangling the dynamics and structure of complex star-forming systems: bar-ends of the star-forming disc galaxy NGC3627 | Star formation is complex due to a web of opposing physical mechanisms acting for and against the collapse of molecular clouds. One scenario that could influence this is the so-called cloud-cloud collisions. Whilst simulations have shown that cloud collisions initiate star formation, observational studies of such regions in extragalactic sources have thus far been limited due to the high resolution needed to separate interacting clouds (a few pc). The bar ends regions of galaxies are regions of active star formation. Therefore, they are exciting regions to study cloud-cloud collisions due to a significant amount of gas buildup. We propose to observe bar ends located in a nearby star-forming galaxy NGC3627 with ALMA at high angular resolution (0.13arcsec; 7pc). We request 17hr of 12-meter time to observe the bulk molecular gas tracer CO(2-1). With these observations, we will resolve individual molecular structures, which will allow us to study a) search for the signature of cloud-cloud collisions, b) the dynamical effects on the gas flows in bar ends, and c) using complementary HST and JWST observations, linking the molecular gas properties to recent star formation and feedback. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-09-25T17:22:53.000 |
| 131 | 2021.1.01650.S | 674 | Towards a systematic redshift determination of HST-dark galaxies | Recent studies have reported a significant population of bright ALMA sources (S870 ~1 mJy) without HST counterparts (H>27 mag, HST-dark), which are likely z=3-7 galaxies and may dominate at the massive end of the stellar mass function. The largest uncertainty in understanding their nature is, however, the lack of spectroscopic confirmation. Previous spectroscopic follow-ups of a small sample confirm their high-z nature, and here we propose (i) ALMA band-3/4 scan towards a flux-limited sample of 13 HST-dark sources with S870>2 mJy, and (ii) deep [CII] observations to confirm redshifts for another 6 H-dropouts with tentative line detections from previous spectroscopic programs, to enable a first statistical determination of their redshift distribution. These observations will lead to spectroscopic confirmation of the largest HST-dark galaxy samples to date(19 galaxies), shed light on their physical properties (including stellar masses, star formation rates, L_[CII]-L_{IR} and L_CO-L_IR relations), and pave the way for future large spectroscopic campaigns, with the final goal to understanding when and how the first massive galaxies are formed in the early Universe. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2022-12-12T17:13:31.000 |
| 132 | 2016.1.00529.S | 23 | Gas kinematics of an extremely young star-forming clump in a disk galaxy at z = 1.987 | We propose for ALMA CO(4-3) observations to probe the gas content and understand the gravitational collapsing phase of an extremely young massive clump in a disk galaxy at z = 1.987. At z ~ 2 star-forming galaxies are gas dominated and host giant star-forming regions (clumps) thought to form due to violent disk instability. However, clumps formation is not understood yet and their contribution to galaxy evolution (e.g., bulge formation) is still debated. Recently we have discovered a galaxy with a bright, off-nuclear emission in spatially resolved emission line maps that is not visible in continuum imaging. For the first time, we are observing a newly formed giant clump (age < 10 Myr, Zanella et al. 2015 Nature). Resolving the CO(4-3) emission in the velocity space we will estimate its underlying dynamical mass and star formation efficiency, firmly establishing which is the star formation mode in young clumps (starburst-like or main sequence-like?). Analyzing the line profile we will look for the presence of infalls and test stellar feedback scenarios, which have a crucial impact on the clumps lifetime estimate, opening a new window into understanding star formation at high-z. | Starbursts, star formation | Active galaxies | 2018-12-19T13:17:45.000 |
| 133 | 2018.A.00038.S | 25 | Further Follow-Up Observations of a Nearby Type II Supernova 2018ivc | The circumstellar material (CSM) in the vicinity of a supernova is a unique probe to the still-unresolved evolution of massive stars in the final decades to centuries. We propose a DDT observation of type II supernova (SN II) 2018ivc in Bands 3 and 6, at ~160-220 days since the explosion (May-June 2019). Our Cycle 6 observation of SN 2018ivc just after the explosion (Nov-Dec 2018) clearly showed the existence of (only) moderately dense CSM (corresponding to the mass loss rate of 10**-4 Msun/yr, assuming the mass loss wind velocity of 100 km/s) extending at least up to ~2 x 10**15 cm. This is qualitatively different from a recently proposed (and widely accepted) scenario, as inferred by optical observations, in which SNe II (may commonly) show an extremely dense CSM (~10**-3 Msun/yr for 100 km/s) only in the very close vicinity (~10*15 cm). The proposed observation will further probe the CSM distribution up to ~2 x 10**16 cm to search for a possible change in the pre-SN mass loss rate and to characterize a diversity in the final evolution of massive stars. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2020-01-10T08:15:00.000 |
| 134 | 2015.1.00860.S | 12 | CO and AGN feedback in massive galaxies | We propose to measure the molecular gas content in three massive elliptical galaxies at the centers of nearby, X-ray bright groups known to contain kpc-extended dust and cooler, multiphase gas. Many recent observational and theoretical studies of the centers of hot gas atmospheres in galaxy groups and clusters conclude that multiphase gas is evidence of non-linear radiative cooling to low temperature. Such cooling is thought to produce molecular gas visible in CO, but so far CO has been detected in only one galaxy/group, NGC5044, during ALMA cycle 0. Here we propose to test this multiphase cooling hypothesis by observing the cores of three nearby group-centered giant elliptical galaxies, all similar to NGC5044. This test is best done with galaxy groups, not clusters, because of their simplicity and proximity. In short: our ALMA observations will reveal or constrain the physical nature of the cooling-accretion-feedback cycle driven by massive central black holes in elliptical galaxies. | Outflows, jets, feedback, Early-type galaxies | Active galaxies | 2017-07-31T18:29:34.000 |
| 135 | 2019.1.00074.S | 96 | On the star-forming and co-evolution nature of less-biased low-luminosity quasars at z > 6 | The recent discovery of high redshift low-luminosity quasars (LLQSOs) provides a less-biased picture of the early evolution of both supermassive black holes (SMBHs) and their host galaxies. We have been conducting multi-wavelength follow-up campaigns of LLQSOs at z > 6, which are several to >10 times fainter than the luminous z~6-7 quasars known to date. In ALMA Cycles 4 and 5, we found that the host galaxies of those LLQSOs have star formation rate about one order of magnitude lower than those of optically-luminous quasars. Moreover, these LLQSOs exhibit ratios of SMBH mass to galaxy mass roughly consistent with values seen at the local universe. However, these less-biased results rely solely on a small number of submm observations (in total 13 LLQSOs at the time of this submission). With this Cycle 6 program, we thus aim at detecting the [CII] line and the underlying FIR continuum emission of another 12 z > 6 quasars selected from our LLQSO catalog, to statistically test the above trend and obtain a comprehensive view of early galaxy-formation. The number of LLQSOs with ALMA measurements will finally become comparable to that of luminous quasars with resolved properties. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2021-07-09T01:23:07.000 |
| 136 | 2017.1.00271.S | 62 | Why is ~ 1/4 of the LMC's molecular gas not forming massive stars? | We propose to map the LMC's quiescent molecular ridge, a GMC complex containing ~1/4 of all of the molecular gas in the galaxy, but which has very little associated massive star formation. The region is 30x below the extragalactic Schmitt-Kennicutt region, and even summing up all of the lower-mass and small embedded clusters still leaves the region inefficient compared to its molecular mass. It is important for any general theory of star formation to understand and explain such a large quiescent system. We propose here to first map the region with the ACA, revealing all few-parsec-scale molecular clumps and their properties. We will investigate whether the region is having difficulty forming forming stars because it can't form dense clumps, or because the clumps are present, but have extra support against collapse. We will determine whether the region is analogous to the dense "bones" of Milky Way molecular clouds. We will release our science-optimized large mosaic to the community, so that the most interesting parts can be followed up at higher resolution and frequency. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-05-11T14:59:32.000 |
| 137 | 2013.1.01070.S | 10 | Direct Imaging of Vertical Structure in an Edge-On Protoplanetary Disk | Protoplanetary disks are proposed to be characterized by radial and vertical gradients in density, temperature, ionization, radiation flux and chemistry. Spatially resolved ALMA SV and cycle 0 observations of molecular lines have confirmed the presence of radial temperature and chemical structures in disks, while constraints on the vertical structures remain scarce. We propose to exploit the exceptional spatial resolution of ALMA and the viewing geometry of the edge-on disk AA Tau to obtain the first direct imaging constraints on the vertical chemical and ionization structure in a protoplanetary disk. We will target molecules and ions proposed to trace the disk atmosphere, warm molecular layer and cold midplane to benchmark our understanding of how disk structures and chemistry depend on disk height. | Disks around low-mass stars | Disks and planet formation | 2016-12-09T21:29:50.000 |
| 138 | 2023.1.00766.S | 0 | Spiralling into the midplane | Detecting planets in their natal discs is essential in the understanding of the phenomenal diversity in properties of detected exoplanets. Recent results have shown the power of ALMA in detecting a population of these embedded planets by revealing strong deviations in the gas velocity structure driven by planet-disc interactions occurring in the disc midplane. The exoALMA planet hunting campaign targeted 15 of the most promising systems for planet detection and has found a variety of spiral arms. However, those were detected in the upper layers of those discs, preventing an accurate comparison with models. Here, we request corresponding observations of the C18O line for 3 sources with the most representative planetary spirals to trace the emission generated in the midplane region. These observations will probe the spiral emission close to the disc midplane, allowing for accurate estimates of planet masses using state of the art analytical models. Moreover, they will allow to study the vertical thermal structure assessed from archival data, which in turn will constrain the propagation of spirals in vertically thermal stratified discs and their properties at different heights. | Disks around low-mass stars | Disks and planet formation | 2025-11-18T18:02:56.000 |
| 139 | 2019.1.01676.S | 10 | Opening a new path in the uncharted territory of high-redshift clumpy galaxies | At redshift z~1-4 giant star-forming regions (clumps) are a common feature of star-forming galaxies. However, the properties (e.g. star formation rate, mass, dust extinction) of those clumps are still unclear. We propose to observe with spatial resolution 0.2" the dust continuum at rest-frame 150 micron of a lensed clumpy galaxy at z = 3.4. A set of ancillary data taken with comparable resolution (rest-frame UV imaging, Hb, [OIII] and Lya spatially-resolved emission line maps) is already at our disposal. With the proposed observations we aim at investigating the dust morphology of our target, comparing it with the UV and optical imaging and spectroscopic data. An inhomogeneous distribution of the dust might suggest that the detected clumps are not physical structures, but the result of the dust inhomogeneities. If instead the dust is homogeneously distributed it will be possible to estimate the dust extinction affecting the clumps. We can also unveil obscured clumps that would not be visible in HST images. We will also detect the [CII] emission with S/N>10, study its distribution across the galaxy, and compare it with the broad and offset Lya emission that we detect from MUSE data. | Starbursts, star formation | Active galaxies | 2021-02-05T20:53:51.000 |
| 140 | 2017.1.01188.S | 60 | Hydrodynamical interaction in the gamma-ray binary, PSR B1259-63 | We propose the multi-band and multi-epoch observation with ALMA for the gamma-ray binary PSR B1259-63 to confirm that a hydrodynamic collision between the pulsar wind and the circumstellar disk really occurs. The emission in the ALMA band 3 can be dominated by the synchrotron component from the shock produced by the collision, and that in the ALMA band 7 can be dominated by the Bremsstralung component from the disk. Thus, by observing simaltaneously the system with the bands 3 and 7, we can investigate the emission from the shock and the disk at the same time, which can be done only by the ALMA. Moreover, by performing a monitoring observation, we can investigate the variation of the condition of the shock and disk, where we expect that the time scale of the variation is about one month. This study could be a key to solving the emission mechanism of this system which remains unclear since the system was discovered. | Disks around high-mass stars | Disks and planet formation | 2019-01-25T13:08:05.000 |
| 141 | 2023.1.01206.S | 0 | Deep molecular gas mapping at the node of the cosmic web at z=3 | In the early universe, galaxies and supermassive black holes are believed to be fed by the gas filaments of the cosmic web. Therefore charting the molecular gas reservoir, the direct fuel of star formation, in the cosmic web filaments is of critical importance for understanding galaxy formation and evolution. The SSA22 protocluster at z=3.1 offers an invaluable laboatry since Mpc-scale gas filaments are identified to connect a number of dusty star-forming galaxies (DSFGs). We propose deep CO(3-2) and band3 continuum imaging toward the node region of the cosmic web filaments in the protocluster taken with both 12m array and ACA. This sensitive census will firstly enable us to (i) uncover the prevalence and importance of molecular gas in the form of accreting gas stream and/or CGMs, (ii) unveil how the cosmic web regulate the galaxy growth, measuring excess/depletions of molecular gas in both star-forming/quenched galaxies, and (iii) test the emergence of hot ICM at z=3 from the experiment to detect absorption feature caused by the thermal Sunyaev-Zeldovich effect. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-10-15T20:10:30.000 |
| 142 | 2016.1.00164.S | 232 | Chemical Diagnostics of Extragalactic ISM: Shock-Induced Evolution in M83 Nucleus | Gas inflow from the bar into the circumnuclear ring is believed to cause gas compression and shocks that lead to subsequent star formation. It is crucial to have detailed observations on how molecular clouds evolve in their physical and chemical properties from this inflow from the bar although such studies are currently lacking. We aim at studying the ISM evolution of giant molecular clouds along the circumnuclear ring of a face-on galaxy M83 using key molecular tracers to diagnose shocked, star-forming and photon-dominated regions. We will observe the whole circumnuclear ring as well as its contact points with the bar in M83. Our observations will reveal the time evolution of molecular clouds after cloud-cloud collisions, the information that observations of individual GMCs cannot provide. Our results can lead to our understanding of the dominant form of star formation in the central few 100 pc of barred galaxies, and in general, at converging points of gas flows in various environment. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2018-03-21T17:16:20.000 |
| 143 | 2023.A.00036.S | 0 | Coordianted ALMA-JWST observations of Sgr A* | We propose to monitor Sgr A* with ALMA as part of a coordinated multi-wavelength campaign during an approved 8h JWST /MIRI observation. The JWST observation is part of an accepted MIRI GO2 proposal, which has already led to a successful first MIR detection of Sgr A*. One JWST observation will be repeated in the time window between August 05 and September 24 due to a guide-star failure, and this proposal requests simultaneous ALMA observations. ALMA submm observations are a crucial addition to anchor the MIRI observation in the context of the overall SED and variability. The JWST observations for the first time probe the distribution of MIR flux densities and spectral slopes in both flare and low-intensity states. Combining those with submm to MIR time lags will distinguish between different emission scenarios. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 144 | 2021.1.00330.S | 18 | An unbiased census of giant molecular clouds in the low-metal dwarf galaxy NGC 6822 | We propose to obtain a CO(1-0) map of the central 12' x 15' (1.7 kpc x 2.1 kpc) region of the low-metal dwarf galaxy NGC 6822 with a resolution of 11'' (25 pc), in order to build an unbiased catalog of giant molecular clouds (GMCs). The proposed depth is sufficiently deep to detect a molecular gas mass of ~6 x 10^4 M_sun even for an estimated CO-to-H2 conversion factor in NGC 6822, which is 30x larger than the Galactic value. The CO(1-0) map properties, i.e., angular resolution and gas-mass sensitivity, will be almost compatible to the existing wide-area CO(1-0) images of local well-studied galaxies including LMC (Nanten), M51 (PAWS), and M83 (ALMA), allowing us to make a direct comparison of GMC properties among these different types of galaxies. Our science goals are (1) Conducting a systematic search for non-star-forming massive GMCs, which is known to be significant in LMC/SMC, (2) Measuring GMC-YSO separations to assess the timescales for the association of GMCs with star formation, and (3) constraining the column density probability distribution functions to test if any external compression exists. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2023-07-23T04:37:36.000 |
| 145 | 2018.1.00321.S | 270 | A survey of 183 GHz water megamasers in nearby AGN | Extragalactic megamasers in AGN are remarkable tools that uniquely probe sub-pc scale geometry and kinematics of the nuclear molecular gas, provide gold-standard masses of supermassive black holes, and allow us to determine geometric distances to galaxies in the Hubble flow. The most scientifically productive megamasers for these studies are so-called disk masers, which demonstrate Keplerian rotation about the central supermassive black holes. Observational work on disk masers has so far been largely limited to studies of the 22 GHz line. With ALMA Band 5, for the first time, we have the sensitivity to probe a water maser transition at 183 GHz with a predicted intensity rivaling that of the 22 GHz transition. Here we propose an exploratory program to search for 183 GHz water masers toward a set of galaxies that are known to have 22 GHz maser disks in Keplerian rotation about the central black hole. This survey aims to establish the detection rate for 183 GHz megamasers, determine their spatial distribution within the accretion disk, and use the 183 GHz lines to probe the physical conditions in accretion disks and measure black hole masses in nearby AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-12-11T18:55:47.000 |
| 146 | 2022.1.01380.S | 0 | B-field-Stabilized Streamers -- Fundamental Accretion Channels? | The exact role of the magnetic (B-) field in the formation and evolution of molecular clouds is still a matter of debate. A central open question is the B-field's possible stabilizing role in guiding accretion in networks of streamers towards central dense objects. It is theorized that, if parallel to streamers, the B-field stabilizes them against radial collapse. If perpendicular, the streamers tend to be narrower. It previous studies in W51e2 and W51e8, with a resolution of 0.1", potential streamer-like features start to appear that connect to the cores, and the B-field appears to be mostly aligned with these emerging streamers. We propose 0.03" continuum polarization observations with the goals to (1) resolve the emerging network of core-connecting streamers in dust continuum and polarization deeper into the central cores, and (2) resolve the B-field morphology towards small disks. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 147 | 2021.1.01557.S | 60 | The Large-Scale Environment of the First Quasars | Virtually all models of early black hole growth postulate that they must evolve from massive seeds and accrete at (super-)Eddington rate most of their life. Consequently, quasars that host billion solar mass black holes should form in the largest overdensities in the early Universe. Despite substantial campaigns in the optical and near-infrared, the predicted overdensities of galaxies around high-redshift quasars have never been detected conclusively, leading the current paradigm into crisis. ALMA observations of z>6 quasars have revealed numerous close (few kpc) companions detected via their redshifted [CII] line. However, these detections only probe the small-scale clustering of quasars and galaxies, leaving the question of whether or not quasars inhabit the first large-scale unanswered. This programme will detect galaxies up to 1.5 Mpc from seven 6 | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-03-30T08:30:39.000 |
| 148 | 2017.1.01320.S | 206 | On the properties of Class 0/I protostellar cores in the Lambda Orionis molecular complex | Stellar feedback (e.g. photoionization, stellar winds and supernova explosions) may shut star formation down or trigger new star formation in different Galactic environments. However, how the stellar feedback influences the new star formation is still unclear. We propose to observe eight Class 0/I protostellar cores located in the Planck cold clumps in Lambda Orionis complex in order to study the influence of stellar feedback on new star formation with the ALMA 12-m array in band 3. We aim to: (1). Study their dust emissivity spectral indices; (2). Investigate whether the envelopes are still in collapse; (3). Study outflow properties (4). Study PDR-like chemistry. The proposed high-resolution (1 arcsec or ~400 AU) observations will shed light on how the properties of dense cores and star formation therein are influenced by radiation feedback from HII regions. The total requested 12-m array time is 2.8 hrs. | Low-mass star formation, HII regions | ISM and star formation | 2019-08-06T16:34:41.000 |
| 149 | 2021.1.00844.S | 10 | An ALMA/JCMT Study of the Time-Variable Class 0 Protostar HOPS 358 and Its (Warped?) Protostellar Disk | The JCMT Transient Survey recently discovered that the Class 0 protostar, HOPS 358, decreased in 350 GHz continuum brightness by 35% over a period of 40 months, with the change likely due to time-variable mass accretion. Based on the Herschel SED, HOPS 358 is thought to be among the youngest protostars in NGC 2068 and therefore an excellent candidate for studying the earliest stages of mass assembly. Fortuitously, the VANDAM: Orion Survey observed HOPS 358 at 0.1" angular resolution with ALMA at 345 GHz before it began to fade, revealing a bright, resolved edge-on disk. For young protostars, the effective disk viscosity determines the mass accretion rate. Thus, measurement of the variations in the accretion rate and the corresponding appearance of the disk, including a potential disk warp seen in the VANDAM observations, will provide vital clues to how protostellar mass is assembled. HOPS 358 presents the first opportunity to directly study a Class 0 disk at various levels of protostellar activity and constrain the physical processes related to accretion. We thus propose to re-observe HOPS 358 with ALMA Band 7, while its brightness remains low. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2023-02-17T22:57:23.000 |
| 150 | 2016.1.01055.S | 76 | Rising from the Dead: Planet Formation and Disk Evolution around Evolved Stars | The detection of giant planets around the post common envelope binary (PCEB) NN Ser is certainly among the most spectacular and unexpected discoveries of extra-solar planets in the last decade. PCEBs are the result of a violent process in which the stars shared a common envelope (CE) of material which was then quickly thrown off. This raises some questions on the origins of these planets, as it is unlikely they could survive this violent process. In a recent paper, we describe the ALMA detection of cold dust around the PCEB NN Ser and demonstrate that this dust is almost certainly material left over from CE evolution. This provides substantial support for the idea that the planets in NN Ser formed from a second-generation protoplanetary disk. This opens unique and exciting new avenues for studies of protoplanetary disk evolution and planet formation. We here propose to (1) observe NN Ser in bands 4 and 7 to provide clear constraints on the particle size distribution of the disk, allowing us to constrain the cause of this dust and (2) observe a sample of systems similar to NN Ser but of different ages to study the time evolution of second-generation protoplanetary disks. | Debris disks, Exo-planets | Disks and planet formation | 2018-02-13T17:01:54.000 |
| 151 | 2023.1.01046.S | 84 | The nuclear mm emission in the most rapidly accreting supermassive black holes at z<0.15 | Recent studies have shown that radio-quiet active galactic nuclei (AGN) ubiquitously show unresolved nuclear millimeter-continuum emission. This 100-200 GHz emission is very tightly correlated with the X-ray emission, which makes it an excellent probe of the accretion power of AGN, even in the most obscured systems (NH> 1e25 cm^-2). However, previous observations do not extend to bolometric luminosity >1e45 erg/s, where the contribution of X-rays to the bolometric emission is expected to strongly decrease. Does the linear relation between mm continuum and X-rays deviate at high luminosities, with the mm continuum following the optical/UV emission? With the observations proposed here we will calibrate the 100 GHz-X-ray correlation at high luminosities, which is fundamental to: i) study accretion in heavily obscured luminous AGN, where most of the supermassive black hole accretion is expected to take place; ii) understand whether the nuclear mm continuum is more tightly related to the optical/UV or to the X-ray emission. This will be done together with a pre-approved Swift/XRT program, which will observe the sources quasi-simultaneously with ALMA. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-10-23T19:41:53.000 |
| 152 | 2018.1.00457.S | 26 | Magnetic fields in circumnuclear plasma torus of radio galaxies | We measure magnetic fields in circumnuclear plasma tori of radio galaxies via Faraday rotation measure (RM) to quest angular-momentum-transfer mechanism of accretion matter. Parsec-scale circumnuclear region of AGNs locates outer edge of SMBH gravisphere. Because matter inside the gravisphere will anyway fall into the central engine, the circumnuclear region controls long-term mass accretion rate. Magnetic field is considered to play an important role on angular-momentum transfer of accretion matter and formation of bipolar jets. To estimate the magnetic field, we propose Band-3, -4, and -6 polarimetry for RM measurements toward two radio galaxies that host a pc-scale plasma torus. The frequency coverage offers a great dynamic range of 10^5 - 10^7 rad/m^2 in RM. Millimeter-wave observations are crucial to avoid Faraday depolarization which results in low polarization degree in cm-wavelengths. The polarimetry capability of ALMA, with supreme sensitivity in mm-wavelength, allows us first evaluation of magnetic fields in circumnuclear regions. We also attemp a byproduct of Zeeman-shift measurements for sulfur monoxide absorption lines to obtain upper limit of magnetic fields. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2020-08-21T10:57:58.000 |
| 153 | 2015.A.00005.S | 20 | Origin of the Gap Discovered at Neptune-Orbit in the TW Hya Disk: Planet vs. CO Sintering | The narrow gap in the protoplanetary disk is one of the clear signs for on-going planet formation. Detecting such gaps is crucial for understanding formation and diversity of extra-solar planets, and has been a long-standing goal for ALMA. Our ALMA cycle 2 observations unveiled, for the first time, a gap in an old gas-rich disk around a young sun-like star, TW Hya. The gap is located at Neptune-orbit (r~25AU) associated with a ring (r~41AU), which can be opened by a planet with super-Neptune mass. Another possible mechanism to form the gap and ring is the microscopic process of sintering of molecular ices, which has been suggested to explain the multiple gaps and rings in the HL Tau disk. Here we propose dust continuum imaging observations at band 4 and 6 to measure the spectral index with high spatial resolution (~0.1"), in order to pin down the origin of the gap and ring by constraining the grain sizes across the gap and ring. Due to the proximity (d~54pc) and location (decl.~-34deg.) of TW Hya together with the excellent performance of ALMA, the proposed observations provide us a very unique opportunity to solve a key question on the origin of the gap in the T-Tauri disk. | Disks around low-mass stars | Disks and planet formation | 2016-07-05T15:36:39.000 |
| 154 | 2023.1.01195.S | 0 | The Size and Albedo of New Horizons Large TNO Targets 2014 OE394 and 2014 OJ394 | NASA's New Horizons (NH) mission is currently executing a campaign to exploit the unique capabilities of a spacecraft traveling in the outer Solar System by making observations of trans-Neptunian objects (TNOs) at viewing geometries unattainable from Earth. Although the sizes and albedos of some of these distant NH targets are well-known, the size and albedo of NH TNOs 2014 OE394 and 2014 OJ394 are only loosely constrained by membership in their dynamical classes, yet these fundamental physical quantities are within reach of ALMA. Measurement of the geometric albedo of these large TNOs, when combined with the phase integral measured by NH, will provide the Bond albedos. The Bond albedo is the ratio of total flux reflected in all directions from a planetary surface to the total solar incident flux; thus its measurement enables evaluation of the thermal energy budget and volatile inventory of a Solar System surface. This combination of ALMA and NH results, will enable comparisons of the surface properties of a cold classical TNO (2014 OE394) and a scattered disk object (2014 OJ394) (using the Bond albedo) to properties of the surfaces of other Solar System objects. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2025-01-12T21:15:59.000 |
| 155 | 2017.1.00510.S | 115 | The ISM of the most luminous starbursts in the early Universe | Using the H-ATLAS survey we have discovered the two most luminous starbursts in the early Universe: SGP38326 at z_spec=4.425 and UR56917 at z_spec=4.420. None of them is lensed according to high-resolution dust and [CII] imaging. Their star formation rates (SFR~4500Mo/yr) and gas depletion times (a few Myrs) means that they are the likely progenitors of the most massive ellipticals at z~3. Here we propose to observe their [CI], high-J CO and water lines which, in combination with the available low-J CO, [CII] and [NII] will give a detailed view of all gas phases of their ISM. The proposed observations will help us understand massive star formation in the early Universe and the birth of the galaxy red sequence. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-02-22T14:44:03.000 |
| 156 | 2015.1.00856.S | 213 | Searching for Molecular Gas in High-Velocity Clouds | We propose to search for molecular gas in the high-velocity clouds (HVCs) of the Milky Way halo. Our understanding of molecule formation and survival in the diffuse, dynamically-complex regime provided by HVCs is far from complete, and only a few detections of molecular gas exist within HVCs. Millimeter absorption line spectroscopy is an efficient and effective tool for detecting this material, and ALMA is uniquely suited to probe a wide range of HVC environments at high sensitivity. The proposed observations will allow us to understand molecule formation in interstellar conditions expected both locally and within galaxies at high redshift. In addition, the presence of molecules in HVCs will help to determine the influence of Galactic feedback and accretion on HVC formation, and will highlight their role of in the evolutionary history of the Milky Way. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-05-11T21:13:08.000 |
| 157 | 2022.1.00729.S | 28 | Accretion shocks and streamers shaping two disks in formation | We propose to observe the planet-forming region of the binary system SVS13-A at a spatial resolution of ~30 au, sufficient to clearly separate the two protostars, and in ALMA Band 3 to minimise dust opacity effects. The two main goals of the proposal are: 1) to unveil the nature of the streamers and accretion shocks suggested by previous ALMA observations and 2) to understand the role of accretion shocks in the chemical enrichment. We will use, in a single spectral setup, bright gas tracers to investigate the cold gas in the streamers (13CO, C18O, CS), the accretion shock (SO, OCS, CH3OH) and the disks region (CH3OH, 13CH3OH, CH3CN). Only ALMA can provide the combination of high-angular resolution and sensitivity to observe the molecular gas at a 30 au scale at 3mm, where the dust is optically thin. The project will shed light on the role that streamers and accretion shocks have on disk formation and chemical enrichment. | Low-mass star formation | ISM and star formation | 2024-11-10T15:03:44.000 |
| 158 | 2013.1.00231.S | 0 | Revealing Magnetic Field Structures: Intermediate-mass Prestellar and Protostellar Cores in OMC-3 | Understanding the magnetic field on size scales smaller than a core (<0.05 pc) is crucial to see how the magnetic field is responsible for setting initial conditions for star-formation. Here, we propose polarization observations in Band7 toward candidates of intermediate-mass prestellar and protostellar cores located in OMC-3, where is the nearest ideal laboratory for studying the magnetically regulated core-collapse process. The main goals are: (i) to spatially resolve the polarization distribution (an angular resolution of 0”.59), (ii) to measure the polarization degree, and (iii) to study how the magnetic field changes with respect to the evolutionary stages of cores. We emphasize that proposed targets are all sitting in the same filaments. Therefore, the natal star-forming environment is same. The obtained results will be compared and iterated with theoretical models (MHD simulations) optimized specifically for our targets. Our previous SMA experiments and the observing simulation tool (demonstrated in this proposal) suggest that these proposed observations will even be able to image the magnetic field structures toward prestellar cores with the sub-arc second resolution. | Intermediate-mass star formation | ISM and star formation | 2017-03-11T15:21:27.000 |
| 159 | 2017.1.00015.S | 521 | What's inside the enormous cavities of FUOr outflows? | We have discovered very large, very wide-angle outflows around the embedded, outbursting protostars known as FU Ori objects or FUOrs. Our previous ALMA 12-m observations provided high resolution imaging that showed the central disk and brightly lit up edges of the outflow cavity but resolved out large scale emission. We propose to mosaic four sources, including FU Ori itself, with the 12m and ACA arrays and the total power antennas. This will produce datacubes of CO and isotopologue lines that sample all spatial scales from about 0.3 arcseconds to the map size of 1 arcminute. We will then map out the outflow structure and kinematics over much larger extents than before and also measure how much gas lies inside the cavities, determine their momenta and energies, search for rotation, and learn about what drives this important early phase of star formation. | Outflows, jets and ionized winds | ISM and star formation | 2019-07-27T00:00:00.000 |
| 160 | 2022.1.00355.S | 28 | Sulfur Chemistry in Massive Star-forming regions | In star-formation studies, sulfur chemistry has long been an intriguing yet challenging topic for astrochemists. On one hand, sulfur-bearing molecules are effective tracers of heated regions in protostellar objects, while only accounting for < 1% of the comic sulfur abundance value. On the other hand, the majority of sulfur is undetected and considered to be locked into dust grains with unclear depletion pathways. In this observation, we focus on probing sulfur-bearing molecules in the dust evaporating massive proto-binary system IRAS 16547-4247 to investigate sulfur chemistry in-depth and further constrain the sulfur budget in star-forming regions. Our multi-band approach would take advantage of the extreme physical conditions of massive hot disks which could destroy refractory dusts with high sublimation temperatures and exceedingly enhance the abundances gaseous sulfur species. The observation will assist us to refine the existing sulfur chemistry network and estimate the total sulfur abundance in the dense ISM. It further benefits the astrochemistry studies of solid evaporation, which drops a hint of the formation of primitive meteorites and thus the origin of our Solar system. | High-mass star formation | ISM and star formation | 2024-09-05T01:01:57.000 |
| 161 | 2019.1.01158.S | 108 | A search for icy collisional fragments among the Jupiter Trojan asteroids | The formation location, and thus the composition, of the Jupiter Trojan asteroids holds the key to understanding the dynamical evolution of the solar system. Unfortunately, solar wind, cosmic ray, and UV irradiation of the surfaces of these objects renders them spectroscopically bland regardless of the intrinsic composition. We propose a search for small fragments of recent catastrophic collisions to probe the interior structure of these objects. This interior structure -- either icy or rocky -- will point to the formation location of these objects -- either within the Kuiper belt or the asteroid belt -- and will allow observational confirmation or refutation of the largest outstanding question in solar system dynamical evolution. | Solar system - Asteroids | Solar system | 2021-01-17T18:27:28.000 |
| 162 | 2019.1.00741.S | 10 | The ISM properties and systemic redshift of a unique double-peaked Lya emitter in the epoch of re-ionisation | Luminous Lyman-alpha emitters (LAEs) are an exciting class of objects in the early Universe (z>6) that probe of the end of the re-ionisation era. One of the most spectacular of those sources is COLA1 at z=6.59, the only double peaked Lyman-alpha emission line known. We have proposed three explanations for the puzzling double peak: 1) COLA1 resides in a large (>2 cMpc) ionised bubble that allows the blue line to redshift out of the resonance wavelength before encountering significant neutral hydrogen; 2) both peaks are red peaks from a merger along the line of sight; 3) the peaks originate from an absorption feature on top of a single broad outflowing peak. Model 1 is particularly interesting as a potential new probe of the process of re-ionisation. We propose to target COLA1 with ALMA to reliably distinguish between the currently open scenarios by determining the systemic redshift with [CII]158um. We will also constrain the obscured SFR using the IR continuum and estimate the gas-metallicity using the [CII]-UV ratio. This will allow us to map out the ISM properties of a unique galaxy that is both a tracer and an agent of re-ionisation. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2022-10-21T14:29:30.000 |
| 163 | 2023.1.00697.S | 174 | Monitoring the extended atmospheres of active AGB stars | Shocks, convection and activity have a major impact on the circumstellar chemistry and mass loss of evolved AGB stars. Using ALMA long baselines, it has been possible to resolve exquisite details of the stellar atmosphere of four AGB stars. These observations show numerous hotspots as well as shock waves close to the actual stellar photosphere. This firmly proves the existence of a (likely shock-heated) low filling factor chromosphere that shows stellar activity. Here we propose to study three of the closest and largest AGB stars in order to obtain the full atmospheric temperature profile. Additionally, we propose monitoring observations to determine the timescale of the hotspots, shocks and convective motions. Such observations are unique as well as crucial for modeling the structure of AGB atmospheres. No other observations exist that can inform the current state-of-the-art models in the required detail! | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2024-11-06T11:20:29.000 |
| 164 | 2018.1.01162.S | 8 | The magnetic field structure in and around the Orion KL outflow | We propose to observe the dense cores surrounding the Orion BN/KL outflow in Band 7 continuum and CO J(3-2) in full-polarization mode for the first time. These observations will build on previous studies of the large-scale magnetic field geometry in the OMC 1 region made by the JCMT BISTRO (B-Fields in Star-forming Region Observations) Survey, and on SMA observations of the BN/KL region, in order to build a complete picture of the magnetic field morphology and energetics in OMC 1 on scales from 0.1 pc to 200 AU, and to achieve the first direct measurement of the magnetic field strength in the BN/KL outflow through observation of the Goldreich-Kylafis effect. Our proposed observations will elucidate the role of magnetic fields in constraining outflows, and of outflows in shaping the geometries of their local magnetic fields. They will allow investigation of the energy balance of OMC 1 on a variety of size scales, in order to determine the relative importance of and role played by the magnetic field in the evolution of this highly complex and non-equilibrium environment. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2020-10-01T13:35:46.000 |
| 165 | 2018.1.01241.S | 3 | The 90 mas imaging of a z = 8.312 galaxy: Benchmarking our understanding of galaxy formation | We propose 90 mas (430 pc) imaging of a z=8.312 Lyman break galaxy MACS0416_Y1, which has recently been detected in the [OIII] 88um and dust continuum emission in our A-graded Cycle 4 program. MACS0416_Y1 has three individual clumps of young stars, and the dust and [OIII] emission apparently traces the stellar distribution. So, one of naive questions is why the dust continuum and [OIII] emission are co-spatial with the UV continuum on ~ a few kpc scale, even though the UV continuum is blue. A possible explanation is patchy/porous geometry of dusty molecular clouds and ionized gas at sub-kpc scales, which are all suggested by state-the-art hydrodynamic simulations of galaxy formation. However, the spatial resolution obtained with the current/upcoming data set from Cycle 4 and 5 (~0.3 arcsec) is not enough. In Cycle 6, we add longer baselines to spatially resolve the internal structures at 430 pc resolution, which is enough to spatially resolve possible giant HII regions, molecular associations, and supernova bubbles, allowing us to benchmark our understanding of galaxy formation through direct comparison with simulations when the age of the Universe was only 600 Myr. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2021-02-21T13:03:11.000 |
| 166 | 2022.1.01676.S | 28 | Testing dust evolution models in T Tau | Multiple stellar system are crucial to understanding planet formation, both for statistical reasons (they are about a half of the stellar population) and because they provide extreme conditions to test our models. Indeed, theoretical modelling indicates that dust coagulation is inhibited by tidal interactions in binary discs. This process can potentially halt dust trapping in bright rings adjacent to emission gaps, which is considered to be the main process to accumulate grains and form planetesimals. We argue that T Tau is the ideal target to test these processes: a gap was recently detected in its bright primary so that we can examine evidence for grain growth and dust trapping adjacent to this gap. Moreover, its secondary and tertiary components are in the close binary regime where models suggest that only very small grains should be present. We propose to observe T Tau at high resolution and sensitivity in band 3 and 4. These data will be coupled with archival band 6 and 7 observations with the aim of studying the properties of dust in this system. Our results will be then compared with the result of similar works targeting single-star discs. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2024-05-17T08:41:26.000 |
| 167 | 2019.1.00261.L | 188 | Early Planet Formation in Embedded Disks | We propose an ALMA Large Program to investigate substructures and physical properties of the embedded disks around 7 Class 0 and 10 Class I protostars at a high spatial resolution of ~5 au (0.04 arcsec) in the 1.3-mm continuum emission and CO (2-1) isotopologue lines. The latest ALMA studies, such as DSHARP, have shown that substructures (rings/gaps, or spirals) are ubiquitous in protoplanetary disks around Class II sources. Such substructures may be a consequence of planet formation in the disks. It is therefore very important to see when substructures start to develop in disks. Because only a few embedded disks around protostars have been observed at a high angular resolution, our large protostellar sample allows us to explore for the first time how ubiquitous such substructures are in embedded disks. Observations in CO isotopologue lines help us to reveal the presence of Keplerian disks, providing us with crucial physical parameters, in particular, the dynamical mass of the protostars. Along with the Class II disk data, these new, homogeneous protostellar data will provide us a unique opportunity to study disk evolution and planet formation at the earliest stages. | Disks around low-mass stars | Disks and planet formation | 2022-12-04T15:31:30.000 |
| 168 | 2016.1.01036.S | 142 | The formation of high-mass binary systems by core/disk fragmentation | Different mechanisms have been suggested to explain the binarity of high-mass stars: core fragmentation, disk fragmentation, and multiple-body interactions. However, so far there is no observational constraints to assess their importance. With the unique capabilities of ALMA, we can for the first time statistically test these scenarios. We will observe continuum emission at 230 GHz to derive the multiplicity fraction and the distribution of companions separation. With a resolution of 0.06" (~100 pc at 2 kpc; ~200 pc at 3.8 kpc), we can resolved star-forming cores and the predicted disks (~1,000 AU) around high-mass stars. We have selected a large, uniform sample of 32 cores containing massive young stellar objects (MYSOs) embedded in 20 high-mass star-forming regions. With these observations, we will address: What is the binarity rate of high-mass cores at ~100s AU scales? How does the binarity rate of high-mass cores change as they evolve? Are high-mass binary systems formed at core scales (~1,000 AU) or disk scales (~1,000 AU)? | High-mass star formation | ISM and star formation | 2018-05-25T18:50:04.000 |
| 169 | 2022.1.00947.S | 11 | The Rise of Metal: 13C in the Epoch of Reionization | We to propose to measure the 13CO(7-6) line in the most massive galaxy known in the epoch of reionziation (EoR), SPT0311-58 at z=6.900. We have designed these observations as an experiment to constrain the abundance of 13C as a cosmological probe of stellar physics and galaxy evolution. If SPT0311-58 is like similar galaxies at z~1-5, we will detect 13CO and C18O, which will provide an important measure of the column density of the gas and provide important constraints on the stellar initial mass function. If, however, we do not detect 13CO, we will still detect C18O and can constrain the star formation history of this massive system in the EoR and confirm an assumption of stellar evolution that 13CO is only produced by evolved moderate mass stars. Either way, this will be an important observation for a multitude of astrophysical communities. Additionally, we target 12CO(6-5) in the sideband which will enable a deep and sensitive search for companion galaxies in this massive overdensity in the EoR. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-01-12T21:41:32.000 |
| 170 | 2021.1.01661.S | 10 | Disk misalignments in the GW Orionis triple system: Disk tearing or planets? | In young multiple stellar systems the gravitational influence of the stars shape the circumstellar disk, controlling accretion and the material available for planet formation. Recent observations of the GW Orionis triple system revealed an extended disk warp and an eccentric dust ring that is strongly misaligned with respect to the stellar orbits & outer disk. Two scenarios have been proposed to explain these misalignments, both supported by hydrodynamic simulations: One team proposed that the gravitational torques of the inner triple system has broken and warped the disk ("disk tearing" effect), while another team concluded that the gravitational perturbation by a planet located in the outer disk is needed to explain the misaligned inner ring. We propose deep CO spectral line imaging that will allow us to (a) search for the velocity 'kink' associated with planets/companions in the intermediate/outer disk, and (b) to measure the gas kinematics in the disk warp and at the disk breaking point. Any planet detection would constitute the first known circumtriple planet. Even in case of planet non-detection, we expect conclusive constraints on the origin of the misalignments in GW Ori. | Disks around low-mass stars | Disks and planet formation | 2022-12-20T15:42:07.000 |
| 171 | 2017.1.00439.S | 21 | A survey of the [NII]205 um / [CII]ratio at z=1 (cycle 5) | We propose to use ALMA band 9 to observe the [NII]205 um transition in three galaxies at z=1.2 from which we have detected emission in the [CII]158 um line. The [CII] transition is emitted by molecular gas ionized and heated by stellar UV radiation, and it is a crucial workhorse in high redshift surveys. The [NII]205 um line is a sensitive tracer of ionized gas, and complements the [CII] line as a star formation diagnostic. We will use the [NII] line to measure the fraction of the ISM in these galaxies that has been ionized by stellar radiation, and use this to determine the intensity of the starburst. We will also use the [NII] line, compared with the continuum emission, to trace the hardness of the UV field, thereby determining the spectral type of the most massive stars or inferring the presence of an AGN. Finally, we will use the [NII]/[CII] ratio to determine how much of the measured [CII] arises from ionized gas rather than PDRs. These observations will be an essential reference for future ALMA high-z [CII] studies. This project is a resubmission of a highly ranked cycle 3 project (carried over to cycle 4). | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-06-05T15:53:04.000 |
| 172 | 2021.1.01706.S | 78 | Core mass function in the lowest metallicity star-forming region in the Galaxy | The shape of the stellar initial mass function (IMF) and whether it is universal are important topics in modern astrophysics. The core mass function (CMF) in nearby star forming regions (<1kpc) is similar in shape to the IMF, suggesting a unified origin. Measurements of CMF in more distant regions have been made possible with ALMA, but observationally it is still largely unexplored whether a low metallicity condition will significantly affect the CMF (and low-mass IMF) shape. The formation of stars at low metallicities is a central problem in galaxy formation and evolution, i.e., to understand the properties of the high redshift universe. However, observationally there are currently few constraints on the detailed star formation properties of low metallicity regions due to large distance of extragalactic sources. Here we propose to survey the dense gas/dust content and measure the CMF in Sh2-284, the lowest metallicity star-forming region in the Galaxy. The proposed study will be complemented by an approved JWST program (ID:2317) aiming to measure the IMF in the same region. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-07-02T00:23:38.000 |
| 173 | 2013.1.00312.S | 15 | Probing Accretion Flows from Filaments to Massive Star-Forming Cores | We propose to investigate filamentary accretion flows in the remarkable IRDC complexes, M17 SWex, where a delayed onset of massive star formation has been reported. Such delay may be explained by a longer accretion time for high-mass end of protostellar mass funciton. Indeed, the dense clumps in this IRDC are found to be at the convergence of multiple filaments of parsec length and display the morphology of hub-filament systems. These hubs are likely nurturing massive protostars and accrete mass through their connecting filaments. We plan to 1) determine the mass accretion rate through filaments to hubs by observing the inflow motions along filaments with N2H+ (1-0); 2) assess the fragmentation in the filaments by identifying dense cores with the N2H+ and continuum emissions; 3) estimate mass accretion onto filaments from the surroudnings by detecting infall collapse onto filaments with HNC (1-0). We will perform a mosaic of 57 fields in Band 3 to cover two hubs and their associated filaments. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-07-31T04:51:41.000 |
| 174 | 2019.1.00479.S | 7 | Hunting for Structures in Protoplanetary Disks around Very Low Mass Stars | The detection and characterization of large mm-cavities of a fraction of protoplanetary disks (transition disks-TDs) has provided new insight into planet formation theories. The majority of the mm-cavities has been resolved around Herbig and T-Tauri stars, but recent discoveries have shown that cavities also exist around very low mass stars (<~0.1Msun, VLMs). One of these is CIDA1, a 0.1Msun object, where we detected a 20au cavity at 0.89mm. Cavities in VLMs disks are challenging all existing models, as the physical conditions in VLMs disks are not favorable to the formation of a cavity by massive planets or photoevaporation. However, only 2 TDs have been detected around VLMs, as most of the existing observations lack the required sensitivity and resolution. We propose to survey the dust continuum emission of a sample of 5 VLMs in Taurus that, as CIDA1, have massive dusty disk relative to Mstar, using ALMA Band 6 at a resolution of 0.1". With these observations, we will estimate how common TDs are around VLMs and to test models of cavity formation. Characterizing a number of TDs among them will be critically important to our understanding of planet formation and disk evolution. | Disks around low-mass stars | Disks and planet formation | 2022-08-30T21:19:20.000 |
| 175 | 2015.1.00307.S | 47 | Debris Disk Structure around Nearby Sun-like Stars | We propose to image the millimeter continuum emission from a sample of the brightest debris disks around the closest (< 20 pc) Sun-like (FGK) main-sequence stars to probe the underlying distributions of dust-producing planetesimals. We will use these data to (1) quantify the surface density structures and assess if the central clearings of these disks result from collisional depletion by an outward moving front of planetoid growth, or dynamical depletion from the gravitational influence of giant planets, (2) use disk features including sharp disk edges, offsets, and azimuthal asymmetries to place constraints on otherwise inaccessible wide-separation planets, and (3) make the first systematic comparative study of the planetesimal structures around Sun-like stars of ~Gyr ages. Analysis of these closest debris disks will provide the cornerstone templates for interpretion of more distant, less accessible systems. | Debris disks | Disks and planet formation | 2017-09-23T21:06:18.000 |
| 176 | 2023.1.00901.S | 0 | Confirming the Detection of Protoplanet Infall or Outflow in HD 163296 | We request time to characterize the first tentative detection of a protoplanetary inflow/outflow. Archival observations revealed a strong bipolar flow traced by atomic carbon emission emanating from one of the HD 163296 dust gaps, believed to have been opened by a massive planet. The detected flow is atomic in nature, confined to velocities independent of those associated with the stellar jet and large scale disk wind, highly suggestive of a protoplanetary outflow(or inflow). The proposal has the potential to confirm a breakthough discovery, the detection of a protoplanet using CI line emission. If the result is confirmed, it will provide unique constraints on the mechanisms of planetary accretion and the early evolution of protoplanet growth. Even in the pessimistic case, a full characterization of the stellar wind and further star-disk interactions is also secured pushing the state-of-the-art knowledge of the field. | Disks around low-mass stars | Disks and planet formation | 2025-07-10T23:50:03.000 |
| 177 | 2022.1.00285.S | 57 | Linking Ice and Complex Molecule Inventories in MYSOs | Massive young stellar objects (MYSOs) host extremely rich and diverse inventories of complex organic molecules (COMs). ALMA has revealed small-scale chemical variations in MYSOs, but the origins of this substructure and the observed diversity of COMs between sources, remain unclear. We propose Band 6 observations at 0.1-0.2" in a pilot sample of three MYSOs with well-constrained ice abundances to further constrain what regulates COM spatial variations and explore links between MYSO gas-phase chemistry and initial organic ice abundances. We will analyze the morphology of all detected COMs, derive spatially-resolved temperature and density maps, and search for links between local temperature, density, and irradiation characteristics and sample properties. When combined with two existing ALMA observations, this sample of five comprises all southern sources with well-constrained organic ice compositions, allowing us to more generally assess the relationship between initial ice abundances and the composition of gas-phase COMs. This pilot study paves the way for future high-resolution surveys of protostellar sources with existing (e.g., VLT, Spitzer) or future (e.g., JWST) ice data. | High-mass star formation, Astrochemistry | ISM and star formation | 2023-12-21T16:58:43.000 |
| 178 | 2021.1.00439.S | 39 | How do clouds regulate star formation? A detailed view of the Antennae merger | We propose to map the nearest major merger, the Antennae, in 13CO(1-0) and CO(3-2) at giant molecular clouds scales (40-100 pc). With active star formation spread out across a range of environments, the Antennae is an excellent proxy for star-forming galaxies and galaxy mergers at moderate redshifts (z=1-2). ALMA obtained complete, high-resolution maps of this iconic system in four CO lines in Cycle 6. We will combine the new and archival data along with Bayesian radiative-transfer models to measure the density, temperature, column density, and [12CO]/[13CO] abundance ratio in individual giant molecular clouds across the Antennae. These new 13CO(1-0) and CO (3-2) data are critical for obtaining accurate constraints on these cloud parameters. With these results, we will obtain a definitive measure of the CO-to-H2 conversion factor, which is likely to vary across the range of environments (nuclei, starbursting "overlap region", disks) in this iconic merger. We will also determine which cloud properties are most important for controlling the local star formation rate. | Merging and interacting galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2022-10-20T19:58:07.000 |
| 179 | 2013.1.00192.S | 2 | What is the Snow Line? Probing Gas Physics at the Phase Transition | Snow lines are inherently interesting transition points in disks due to the possible role they play in the formation of rocky and icy planets. Thus the recent discovery of a resolved ring of N2H+ emission tracing the CO snow line in the TW Hya protoplanetary disk provides an exciting opportunity to study the chemical and physical effects at the phase-transition region. With the proposed follow up observations presented here, we endeavor to fully physically characterize the opacity and thermal properties of the N2H+ ring using fundamental molecular emission physics to paint a complete picture of temperature (via line ratios), spatial distribution (at 2x higher resolution than previous observations) and opacity (exploiting the line's hyperfine structure) of the N2H+ emission. This information is key to fundamentally understanding the properties of the gas at the transition region and to aid in its interpretation as a snow line or otherwise. | Disks around low-mass stars | Disks and planet formation | 2016-09-10T23:26:51.000 |
| 180 | 2016.1.01272.T | 41 | Impact of a global dust storm on Martian atmosphere (retry) | The most striking phenomenon on Mars is a planet-encircling storm, so-called "global dust storm". Once it starts, floating dust covers the whole atmosphere for more than one month, and heats up the global atmosphere via absorption of solar radiation. Our simulations predict that atmospheric temperature rises more than 20 K at 10-60 km altitude over the planet under such global dust storms and the heating also accelerates the dynamics. Moreover, theoretical studies predict the amount of CO could increase due to triboelectric field under a global dust storm. The goal of this proposal is to quantitatively evaluate how much change is induced in thermal structure, dynamics, and CO due to a global dust storm. We propose a ToO observation of 12CO and 13CO lines in Band-6 during and after a global dust storm event. Through conscious monitoring of dust opacity by Mars Express spacecraft, we can trigger to carry out the observation in real-time. In addition, this is a unique opportunity to perform joint observations with ExoMars Trace Gas Orbiter. This new sensitive observation of dust-covered Martian atmosphere with ALMA will provide essential understanding in the meteorology and climate. | Solar system - Planetary atmospheres, Solar system - Planetary surfaces | Solar system | 3000-01-01T00:00:00.000 |
| 181 | 2016.1.00650.S | 48 | Pattern Speed in the Double-Barred Galaxy: NGC 3504 | We propose to establish a new method using molecular gas to study the pattern speed of the inner bar in a double-barred galaxy. The pattern speed is a key property in studies of galactic dynamics, affecting the evolution of a galaxy. However, it is difficult to measure especially for double-barred galaxies, for which the inner and the outer bars are characterized by different pattern speeds. In contrast to using the Halpha line, we choose the CO(2-1) line as a tracer to use the phase reversals method. This is more fundamental since the CO line traces the continuous star forming regions. This is the first time this new method is applied at radio wavelengths for an observation with high angular and velocity resolution. Once this new method has been demonstrated for the CO line, we will apply it to other galaxies. To achieve our goal, we propose to observe the double-barred galaxy NGC 3504, which is nearly face-on and can be resolved by ALMA in a reasonable time. Our high sensitivity and high resolution data of molecular gas will provide essential input for studies of the effects of the bar pattern speed on the kinematics and morphological properties in the inner region of the galaxy. | Galactic centres/nuclei | Active galaxies | 2019-01-12T00:00:00.000 |
| 182 | 2023.1.01347.S | 12 | 50 pc resolution imaging of jet-ISM interaction in young AGN | Studies of quasar host galaxies are important for understanding the AGN-host coevolution. However, the local property of the quasar host galaxies has not been fully explored in the early universe. In order to circumvent the problem, we use gravitational lenses as natural telescopes. They enable us to resolve ISM around a massive AGN with a spatial resolution of <50 pc. With this resolution, we will be able to directly image the host galaxy that interacts with the AGN jets. Using a de-lensing technique, the interaction between young jets and highly excited CO gas in a radio loud quasar has been detected recently. However, the property of the ambient ISM has not been probed yet. In this proposal, we aim to observe diffuse CO gas to determine the kinematic property of the ambient ISM in a quasar at z=2.639. Using a de-lensing technique, we will be able to resolve the low-energy CO gas on ~50 pc scales. Our observations will pave the way to understand the infant stage of AGN that may eventually evolve into a massive radio galaxy. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-10-24T01:45:04.000 |
| 183 | 2021.1.01164.S | 21 | Pinpointing hot methanol transitions with observational and experimental data | Methanol is thought to be the parent molecule of many complex organic species. At the same time, it is also a useful diagnostic tool for studying physical properties. Hence it is crucial to obtain methanol abundance accurately. However, the emission of methanol sometimes including its isotopologues, are optically thick, making the derived abundance unreliable. With the new laboratory spectroscopic data of not only methanol but also its rare isotopologues, we propose to perform a spectral scan covering the same frequency range as the laboratory measurement (216-264 GHz) toward a chemically rich low-mass protostar. This will allow us to obtain accurate methanol abundance with its highly excited transitions and search for unreported isotopologues. Their spatial distribution will give us information on their chemical origin and detection of rare isotopologues will enable study of molecular fractionation e.g. D/H, 17O/18O in the source. Finally, by comparing the observational data directly with the experimental measurement, we will identify the weed lines of methanol and its isotopologues which will be valuable for future line identification of new species in the ISM. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-12-23T02:10:19.000 |
| 184 | 2017.1.00827.S | 3 | Probing the Physics of Radio-Mechanical AGN Feedback with ALMA | We propose observations of the Sunyaev-Zel'dovich effect in galaxy cluster MACS J1931-2634 in order to constrain the nature of radio-mode AGN feedback. During radio-mode feedback, AGN jets inflate cavities in the surrounding intracluster medium, heating it; however, the partition of energy among thermal gas and cosmic rays in the cavities is unknown, as are the details of how energy is transferred to the surrounding gas. MACS J1931 hosts one of the most powerful radio-mode AGN known, and represents a more massive, intermediate redshift analog of well studied, nearby clusters such as Perseus. This proposal will, for the first time, directly constrain the contribution of thermal pressure in supporting AGN-driven cavities. We will also constrain the power spectrum of pressure fluctuations in the hot gas; combined with measurements of the density power spectrum from existing X-ray data, this will determine whether the perturbations sourced by the AGN are primarily in p-modes (turbulence/shocks) or g-modes (slow motions). This project, for which ALMA is uniquely suited, will thus provide key insights into how supermassive black holes interact with their galaxy and cluster environments. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy groups and clusters | Active galaxies | 2022-03-09T20:37:45.000 |
| 185 | 2018.1.00171.S | 60 | A search for the peptide-like molecule HNCO in protoplanetary disks | HNCO is a prebiotic molecule thought to be involved in the formation of larger peptide-like molecules. Its presence towards molecular clouds, protostellar sources and in comets is well established, but a detection in a protoplanetary disk has not yet been made. Recent successful detections of CH3CN and CH3OH in disks show that it may be possible to detect HNCO as well. We propose to observe the HNCO 11,0-10,0 transition at 241.774 GHz in the protoplanetary disks around the Herbig Ae MWC480 star and the T Tauri stars AS 209 and V4046 Sgr. Deep ALMA Band 6 integrations down to 2 mJy will make it possible to observe this line, which is calculated to have a peak brightness of ~10 mJy in a beam-filling source. A successful detection of HNCO in a disk will present the missing link between HNCO observed around protostellar sources and in comets. It will also make a strong case for the presence of more complex peptide-like molecules in protoplanetary disks and their incorporation in comets. | Astrochemistry | ISM and star formation | 2020-08-14T15:09:34.000 |
| 186 | 2013.1.01330.S | 3 | Resolving the Cosmic Snake, a typical L* galaxy at z=1.036 | We propose to obtain CO emission map of the Cosmic Snake, a lensed, typical L* galaxy at z=1.036, dominated by ordered disk rotation. The requested spatial resolution (0.19") is comparable to HST in order to resolve the spectacular clumpy structure revealing 20 multiple imaged clumps with 0.15" radius. Thanks to lensing magnification we will resolve these clumps down to intrinsic radii of 0.01" or 100 pc. Deriving the molecular gas properties and kinematics of star-forming clumps at sub-kpc scales, below the expected scale-length for the Toomre gravitational instability of clumps in gas-rich turbulent disks, will be a first for a typical L* z~1 galaxy. The combination of ALMA data with the wealth of ancilliary data including Halpha kinematics will allow a complete characterization of the physical properties for each clump enabling us to test the Kennicutt-Schmidt law at sub-kpc scales in a z~1 galaxy, and the universality of the Larson relations for giant molecular clouds. We will also explore the variation on physical parameters of CO-H2 conversion and compare the derived kinematics with predictions from simulations putting constraints on the origin and fate of these clumps. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2016-08-04T10:34:00.000 |
| 187 | 2019.1.00570.S | 8 | Probing Jet Rotation in a Protostellar Jet | Protostellar jets are believed to be launched from accretion disks around protostars, carrying away extra angular momenta from the disks, allowing material to fall onto the protostars. Their launching radius and thus model (X-wind v.s. disk-wind) are still uncertain but could be determined from their rotation properties, which can be measured with ALMA's unprecedented sensitivity and resolution. HH 211 is a nearby source with well-defined jets lying almost in the plane of the sky, and its first pair of knots being within 100 AU of the source, ideal for jet rotation measurements. We have previously mapped this source at ~0.05" resolution in Cycle 4 with a tentative detection of jet rotation. Here, we propose to observe HH 211 with ALMA at ~0.016" resolution in order to fully resolve the position-velocity structure and measure its rotation precisely. By measuring the jet rotation properties accurately, we can calculate the jet launching radius and determine the jet launching model without the need to resolve the inner-most part of the disk near the protostar. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2022-12-23T02:55:27.000 |
| 188 | 2017.1.01280.S | 56 | The complete ALMA view of the Orion Bar: unexpected structures and processes | We propose to obtain wide-field sub-arcsecond resolution images (0.7'' ~300 AU) of the iconic Orion Bar PDR in the bright CO 3-2, HCO+ 4-3 lines, and 850 microns dust continuum emission. The proposed observations will allow us to generalize the unexpected results obtained from our pilot ALMA images of a very small field of the Bar edge (published in Nature). We will investigate the properties of the fragmented ridge of high-density substructures, cloud surface instabilities, and photo-evaporating flows revealed by these first ALMA mosaics. In addition, and to better understand why the H/H2 and C+/C/CO transition zones are so close in the Bar, we request pilot observations of the [CI]492 GHz line. These observations will be interpreted with a new non-stationary model that treats the PDR hydrodynamics and time-dependent chemistry. Therefore, we will be able demonstrate the dynamical and non-equilibrium nature of the interaction between UV radiation from massive stars and their parental molecular cloud. These questions are at the core of our understanding of the stellar radiative feedback, a process taking place at many galactic and extra-galactic scales. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2020-01-24T00:00:00.000 |
| 189 | 2022.1.00660.S | 18 | The Assembly of Early Massive Quasar Host Galaxies | The existence of billion solar mass black holes (BHs) at z>~6.5 and the detection of strong gas and dust emission in their hosts indicate fast build-up of both the earliest supermassive BHs and their massive host galaxies. Recent ALMA [CII] imaging of z~6.5 quasars suggests a diverse range of morphology and kinematics, indicating a complex growth history of these massive systems. However, limited by the spatial resolution and the lack of detection of the hosts' stellar light, the assembly history of these massive galaxies are still poorly understood. We propose ALMA high resolution (~0.1" - 0.17") observations for five remaining targets from a representative sample of bright quasar host galaxies at z>6.5. Together with the approved high resolution JWST observations for the stellar emission in rest-frame UV/optical, the proposed ALMA sample will provide unparalleled constraints on the gas structure, morphology, kinematics, dynamical mass, spatially resolved star formation surface density, and dust reddening of these massive hosts, which will finally enable us to understand the assembly of the first massive galaxies in a statistical manner from a multi-wavelength perspective. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2024-06-27T15:42:14.000 |
| 190 | 2016.1.00110.S | 20 | Circumstellar Disks of the Most Vigorously Accreting Protostars | We will carry out dust continuum and CO isotopologues lines observations of FU Orionis (the prototype of FUors) and Z CMa, two protostars that experienced dramatic outbursts decades ago, at Band-6 with 0".05-0".1 resolution (~45 AU at their distances). This team has recently discovered spiral-arm like features in scattered light images of these disks (Liu et al. 2016). These observational evidence strongly suggest FUors are gravitationally unstable protoplanetary disks currently undergoing fragmentation, based on our numerical modeling results. The proposed observations will either find spiral arms and dense clumps produced by gravitational instability (GI) with high S/N ratio, firmly confirming the GI nature of these systems, or definitively rule out the presence of these structures as in our models. Our proposal is built on extensive hydro + radiative transfer + CASA simulations, and is part of a large coordinated effort to understand the FU Ori phenomenon by combining hydrodynamical calculations, radiative transfer simulations, and observations using both 8-m class ground-based telescopes and ALMA. | Exo-planets | Disks and planet formation | 2018-11-10T12:03:50.000 |
| 191 | 2013.1.00839.S | 24 | Revealing the Low-Mass End of the Core Mass Function in Rho Ophiuchus Star Forming Region | The origin of the stellar IMF is a fundamental unresolved problem in star formation. Recent millimeter and submillimeter observations of the rho Ophiuchus cluster-forming region uncovered prestellar cores with a mass spectrum (hereafter, CMF) that resembles the Salpeter IMF. The implication is that the IMF may be determined to a large extent by the core mass distribution from cloud fragmentation. However, the low-mass ends ( < 0.1 Msolar) of the CMFs remain to be elucidated observationally because of the lack of high spatial resolution observations. In order to clarify the link between the CMFs and IMF, it is crucial to derive the low-mass end of the CMFs. Here, we propose mosaic observations toward the dense regions of the nearst cluster-forming region, rho Ophiuchus, at a distance of 120 pc. | Low-mass star formation | ISM and star formation | 2021-03-04T00:00:00.000 |
| 192 | 2013.1.00861.S | 1 | Star formation in the outer parts of XUV disk galaxies | Results from the UV satellite GALEX have revealed a surprising large extension of some spiral disks of nearby galaxies. While the H$\alpha$ emission, the usual tracer of star formation, especially in the outer disks less affected by dust extinction, drops down at the border of the optical radius, the XUV emission extends out to $3-4$ times this radius. This provides evidence of outer star formation and of molecular gas up to the limits of H\,I observations. We propose take advantage of the unique sensitivity of ALMA to map a bright UV region in M83, located at $r_{gal}=1.3r_{25}$, which is also rich in HI emission. By using band 6 to observe CO(2-1) we aim to trace the faint molecular gas expected at this large galactic radius where star formation is more difficult to occur. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-11-19T00:00:00.000 |
| 193 | 2019.1.00227.S | 9 | Running on Empty: Probing the Gas Reservoirs of the REQUIEM Lensed Quiescent Galaxies at z=1.6-3.2 | Using HST imaging and follow-up rest-frame optical spectroscopy, we have identified a remarkable sample of ten strongly lensed massive (10.5 | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2021-03-27T22:12:20.000 |
| 194 | 2016.1.00984.S | 164 | Infall Toward Massive Starless Clump Candidates | Massive starless clumps are the nascent phase of intermediate and high-mass cluster formation prior to the formation of protostars. An evolutionary analysis of the Bolocam Galactic Plane Survey has identified over 2200 massive starless clumps in the first quadrant of the Milky Way. Follow-up observations of this sample with the Arizona Radio Observatory 12m telescope in the optically thick, intermediate density tracer HCO+ 1-0 have now identified massive starless clumps with the spectroscopic signature of collapse (a blue-asymmetric profile with optically thin species peaking in the absorption dip). This subset of starless clumps may be on the verge of protostar formation; however, the ARO spatial resolution of 70" only provides a global view of the kinematic state of the clumps. We shall use ALMA to probe, for the first time, the kinematics structure down to the scale of cores (< 0.05 pc) for a sample of 5 nearby (D < 6 kpc), massive (250 < M < 800 Msun) starless clump candidates that have signatures of infall. ALMA observations will distinguish between models of global inflow and core infall. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-03-07T23:35:55.000 |
| 195 | 2013.1.00911.S | 20 | Molecular gas conditions and shocks in the superwind of the starburst galaxy NGC 1808 | We propose multi-line observations of the starburst galaxy NGC 1808 motivated to study the state of the neutral interstellar medium in a prototypical starburst galaxy with a superwind. The study aims to address: 1) the physical conditions of the molecular gas in the starburst region of the galaxy, which is the origin of a polar dust outflow, 2) the energetics (mass and kinetic energy) of the molecular gas in the outflow, and 3) the dense shocked gas to trace the evolution of molecular clouds in the past starburst episode. The methods consist in observations of the molecular lines of CO, HCN, HCO+, SiO, and CS, and modeling the physical conditions with radiative transfer analysis. CO(3-2), HCN, HCO+, and CS reveal the dense molecular gas, and SiO is a reliable tracer of dense shocked gas. NGC 1808 is one of the few nearby starburst galaxies with prominent superwinds - a valuable target to address the wind feedback, while demonstrating the capabilities of ALMA. | Starbursts, star formation | Active galaxies | 2016-03-23T14:27:21.000 |
| 196 | 2013.1.00351.S | 8 | The failure of galactic star formation relations on sub-galactic scales: A direct probe of the physics of star formation | We propose to map CO(1-0) emission over a quarter of the optical disk of the nearby (1.9 Mpc) flocculent spiral NGC 300. These data will measure the structure of molecular gas with high spatial (23pc) and spectral (0.32 km/s) resolution and reveal ~500 molecular clouds (MCs), making this one of the finest (extragalactic) MC samples. We will apply these data to a newly developed model - the `uncertainty principle of star formation (SF)' - that relates the scatter in resolved SF and gas tracers (i.e., the `breakdown' of the Kennicutt-Schmidt relation on small scales) to the evolutionary state of SF regions. The model derives the timescale of MC formation, the duration of SF, and efficiency of stellar feedback - all critical parameters of galaxy evolution that are hotly debated. We will also smooth the data to lower resolution to calibrate the model for future ALMA observations of more distant galaxies, opening up a much wider range of environments. NGC 300 is the ideal target as it has a smooth, flocculent, undisturbed gas disk seen at low inclination with active SF, rich ancillary data, and an ideal distance to map a wide area at high resolution and sensitivity within modest time. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 3000-01-01T00:00:00.000 |
| 197 | 2016.1.00864.S | 33 | Quenching mechanisms in dense environments at high-redshift: Mapping the molecular gas in cluster galaxies at z~1.5 | Although the star formation-density relation, in which galaxies with little star formation are preferentially found in high-density regions, is established up to z~1.5, there is little evidence on the processes that suppressed star formation in dense environments at earlier times. A way to investigate quenching mechanisms at high-z is to quantify the main fuel of star formation, namely their reservoirs of cold molecular gas and study its dependance with local density. We propose to probe the molecular gas in cluster galaxies in two structures at z~1.5 by targeting CO(2-1) with 3mm observations. The clusters are unique systems as their filamentary structure suggests that they are still in the process of collapsing but the fraction of red galaxies in their cores advocates that quenching processes are already at play in the inner regions. We will target ~40 cluster members (20/cluster) and derive molecular gas masses for the most gas-rich ones. We aim to quantify the molecular gas content in these galaxies and study the dependance of gas fraction with cluster location. We will further study the spatial scales over which the processes that switch off or strip the gas may occur. | Galaxy Clusters | Cosmology | 2018-06-07T01:54:17.000 |
| 198 | 2013.1.00327.S | 155 | The Evolution of Young HII regions | At the birth of a massive protostar, newly formed HII region expands into the surrounding medium. For the most part, our understanding of how and why are rooted in the Stromgren models, with only a few numerical simulations moving beyond this (e.g. Keto 2002, Peters et al. 2010). In order to understand the dynamics, feedback and disruption of molecular clouds caused by massive stars shortly after they form HII regions, requires high-resolution sub-mm observations. From these observations, we can determine how the HII regions expand, leading towards answering why. Here we propose Band 6 observations at 0.4'' of 9 small HII regions. We will use H29a to trace the dynamics of the ionised gas and three molecular species to trace the warm and dense gas around the HII regions. Through high sensitivity observations at the same resolution in both gas populations (ionised and molecular), we can understand the interaction between the HII region and its surrounding material as the ionisation front expands into it. | High-mass star formation, HII regions | ISM and star formation | 2016-02-19T14:15:34.000 |
| 199 | 2017.1.00885.S | 0 | Sulphur in protoplanetary disks - a zero-sum game | Sulphur plays an important role in disk ionization and affects planetesimal differentiation. Its budget in protoplanetary disks is currently poorly known. Observations suggest >90% of volatile sulphur is missing from the gas. The main volatile S carriers are CS, SO, SO2, and H2S, but no single one has yet been shown to carry more than a few percent of the total S. Importantly, a deep molecular census of S-bearing species has not been obtained for any source. We will use ALMA and our published physical-chemical model for the HD 100546 disk to obtain a spatially resolved census of the main (and a number of secondary) sulphur-bearing molecules in its dust-depleted inner cavity. Comparison of their summed abundances with the stellar S/H ratio will reveal whether there is a need to invoke new volatile sulphur reservoirs, such as a large abundance of sulphur chains. Further insight will come from a comparison with S-bearing ices in comet 67P from Rosetta. | Intermediate-mass star formation, Astrochemistry | ISM and star formation | 2018-12-15T08:43:05.000 |
| 200 | 2012.1.00012.S | 0 | Expanding the frontiers of chemical complexity with ALMA | The search for complex pre-biotic and biotic molecules in the interstellar medium (ISM) will be a primary focus of ALMA science. The molecular inventory of meteorites found on Earth includes more than 80 distinct amino acids (the building blocks of proteins), and their composition suggests an interstellar origin. The key search site for new complex organics in the ISM is the hot dense core Sgr B2(N), due partly to its high column density. However, the firm identification of new molecules requires a robust spectral model to unweave the emission lines of weakly-emitting, more complex, species from known molecules. We have already constructed a unique model of this kind, using our previous single-dish line survey, which has already allowed our team to uncover several new species. We propose to use ALMA Early Science to perform a deep, unbiased line survey of Sgr B2(N) in band 3. The proposed survey will improve the detection threshold for complex organic molecules by nearly a factor of 30 compared to our previous survey of this source. Such a sensitivity improvement should lead to the firm detection of a few, perhaps a dozen, new complex organics, while the adaptation of our existing spectral model will allow a rapid turn-around from detection to publication. The use of our team's cutting edge chemical models will allow the broader implications of new discoveries to be understood, and place strong constraints on chemical formation pathways. The discovery of biologically-relevant molecules in the ISM will be of high scientific impact, and is of broad appeal to the public and the media. The combination of ALMA's unique spectral sensitivity with our established methodologies will provide an efficient showcase of ALMA's capabilities in this field. | High-mass star formation, Astrochemistry | ISM and star formation | 2015-05-09T14:14:49.000 |
| 201 | 2019.1.00399.S | 9 | Star formation in a massive z=2.91 halo fed by cold accretion | We recently discovered and spectroscopically confirmed a structure consistent with a forming, single massive halo at z=2.91 in the COSMOS field. With a total mass of ~5x10^13Msun, this is the highest redshift bonafide cluster/group known. Keck/KCWI observations revealed a luminous Lya nebula well centered on the stellar mass overdensity, surrounded by three filaments with a factor of >10 lower surface brightness, extending over a 320pkpc diameter out to the virial radius. A variety of observables suggest that we are a textbook-case of cold accretion onto a massive high-z halo. Existing multiwavelength data, including an ALMA 2min snapshot, only scratch the surface of the star formation content of this system. We propose to image with ALMA at 870um an area of 20x40'' fully covering the cluster candidate and associated Lya nebula, enabling detection of any galaxy with >10Msun/yr, about 40x deeper than current limits. We will unveil the luminosity and spatial distribution of star forming galaxies in this unique structure, enabling us to study directly the connection between cold streams and the feeding of star formation in galaxies in one of the earliest forming structures known. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2021-02-19T16:45:10.000 |
| 202 | 2021.1.01005.S | 384 | Searching for the Missing Galaxies in Extreme Absorption-Selected Protoclusters | Lyman-alpha tomography provides an exciting new way of mapping large-scale structures and studying environment-dependent galaxy evolution in Cosmic Noon era. The LATIS survey has now produced 3D maps of the intergalactic medium opacity, which is closely related to the matter density field, over large volumes at z~2.5. Regions with moderately strong Lya absorption in the LATIS maps are found to be populated with Lyman-break galaxies (LBGs) as expected. Yet the regions with the strongest absorption, thought to correspond to massive protoclusters, are strikingly deficient in LBGs. This suggests that they are dominated by a galaxy population absent in UV surveys. Remarkably, the most massive protoclusters, even in well-studied fields like COSMOS, may have been missed because they are almost UV dark. We propose to identify sub-mm-selected galaxies associated with two of these LATIS structures by searching for CO(3-2) emission near the structures redshifts. We will make efficient use of ALMA by surveying two UV-dark structures that (1) overlap on the sky, (2) can be scanned for CO(3-2) with a single tuning, and (3) benefit from deep SCUBA-2 imaging enabling the selection of 38 targets. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-02-03T08:51:02.000 |
| 203 | 2019.1.00850.S | 6 | Probing jet structure in DG Tau with radio recombination lines | Jets from young stars are essential to remove angular momentum from the system which allows accretion to proceed. In low-mass stars, these jets consist of several layers, where the inner components are faster, hotter, and more collimated than the outer components. In this proposal, we focus on the innermost and fastest jet components that carry only a small fraction of the outflow. Using ALMA's superior spatial and spectral resolution, we plan to detect hydrogen recombination lines where the fully ionized plasma in the inner jet components recombines. This technique has been used for ionized winds and jets from high-mass stars, but never in low-mass stars. This measurement will resolve the position of the ionized component of the jet, and measure its mass flux and radial velocity. Thus, we will have a complete mass and energy budget for this jet component for the first time, which is essential to distinguish different jet launching and heating scenarios. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2023-05-13T00:00:00.000 |
| 204 | 2015.1.01455.S | 30 | The origin of H2O emission and molecular outflows in IR-luminous galaxies | Water lines provide a unique probe of luminous IR galaxies, since (unlike e.g. CO) they measure the local IR radiation field. Herschel has shown that all local ULIRGs emit strong H2O lines, from highly obscured (FIR-opaque), IR-luminous regions with high local IR radiation pressures, which may play a role in driving the molecular outflows. We will take a major step forward with the first spatially resolved study of H2O emission (3 lines, providing the full diagnostic power), FIR continuum, OH+ emission/absorption (tracing the molecular outflow) and CO(7-6) and [CI] (tracing the high and low excitation molecular gas). We will observe these lines in 3 gravitationally lensed galaxies (Cloverleaf, Eyelash and SDP17b at z=2-2.5), at 0.2-0.25" resolution, obtaining the full position dependence of excitation conditions, importance of radiation pressure, occurence and velocity of outflow, and relation to the underlying gas disk. This is a resubmission of uncompleted observations from programs rated in the highest priority bin in Cycles 1 and 2. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2018-03-13T12:38:38.000 |
| 205 | 2013.1.00588.S | 2 | Constraining the Inner Disk Edge of the Solar Analog tau Ceti | tau Ceti is the nearest G-type star (3.65 pc) that harbours both a debris disk and planets, with 5 known super Earths tightly nestled inside 1.5 AU. It appears to be a close analog to our Solar System, except that it is missing giant planets on wider orbits, though because of observational biases, if there were any they would not have yet been detected. We propose to use ALMA to image the inner edge of tau Ceti's disk and infer the presence of an unseen massive planet that could be clearing the central hole in the resolved disk. | Debris disks, Exo-planets | Disks and planet formation | 2016-01-15T18:42:26.000 |
| 206 | 2017.1.00975.S | 86 | Searching for the Smoking Gun of Magnetar-Powered Super-Luminous Supernovae | Nascent strongly magnetized neutron stars (so-called magnetars) with rapid rotation have been considered to explain optical emission of super-luminous supernovae. They also give us a unified picture of stripped-envelope supernovae, gamma-ray bursts, and even fast radio bursts. Pulsar wind nebulae are known to be efficient accelerators of electrons and positrons, so non-thermal synchrotron emission from the nascent nebulae is naturally expected. We propose to observe two super-luminous supernovae, SN 2015bn and SN 2016ard, with ALMA. Contrary to low-frequency radio emission that is largely suppressed by free-free absorption, submm synchrotron emission serves as a smoking gun of magnetars hidden in the supernova ejecta. A successful observation will provide us with the first evidence for a magnetar-like central engine as well as a clue to progenitors of fast radio bursts. Even non-detections will set stringent constraints on the magnetar-powered supernova model. | Transients | Stars and stellar evolution | 2019-04-17T20:21:51.000 |
| 207 | 2017.1.01675.S | 124 | Test the chemistry of turbulent grain motion in a dark cloud. | Turbulence and chemistry play key roles in regulating molecular cloud and star formation. Beside the traditional relationship between the turbulence and chemistry (turbulent transport, heating and megnetical driving to ions), a new connection has been found in recent years: MHD turbulence drives random grain motion that modifies the grain accretion of gas in the gas-grain chemistry. Our published modeling work has demonstrated profound chemical effects induced by turbulent grain motion in typical interstellar medium. We propose Band 3 and 6 mapping of a collection of chemical tracers to the starless core TUKH122 in Orion A to test this effect for the first time. If successfully confirmed, the phenomenon may open a new avenue to studying interstellar turbulence and grain dynamics. | Astrochemistry | ISM and star formation | 2019-08-06T00:00:00.000 |
| 208 | 2015.1.01344.S | 66 | The initial conditions of Galactic Center Super-Cluster precursors: an ALMA survey of A_V >50 massive clumps along the 100-pc Ring. | The formation of Galactic Super-Clusters like the Arches or the Quintuplet requires that certain environmental conditions are available. A massive dense clump precursor must be assembled and kept stable against fragmentation long enough to form massive stars; on the other hand a strong triggering mechanism must be available to justify the formation of a cluster with a top-heavy IMF. The recent discovery of a 100-pc ring of dense and cold clouds orbiting around the Galactic Center (Molinari et al. 2011) may provide a suitable structure in which both these conditions may be verified: indeed the 100-pc ring hosts the best candidate for Arches-like cluster precursor to date (Longmore et al. 2012), as well as the best example of a cloud-collision induced burst of star formation (Sgr B2). We propose to carry out an ALMA continuum and line survey of the 20 denser clumps (A_V > 50mag) along the portion of the 100-pc ring before their passage close to Sgr A*. The aim is to determine the initial conditions of the dense clumps that the 100-pc ring is assembling, before any triggering or compression event (like the passage close to Sgr A*) that can lead to the formation of Brick-like clouds. | High-mass star formation | ISM and star formation | 2017-10-12T07:05:22.000 |
| 209 | 2016.1.00142.S | 26 | Through the magnifying glass: a unique view of the low-metallicity ISM at high redshift | Low-mass galaxies produce up to half of the new stars at the heyday of galaxy formation, yet our knowledge of the physical processes at this epoch is almost solely based on extrapolations from either lower redshifts or higher-mass galaxies. An exceptionally rare lensing configuration has 30-fold magnified a dwarf starburst galaxy at z=1.847, providing a unique opportunity to explore the ISM conditions in this important but thus far unobservable regime of galaxy evolution. We propose to take advantage of the magnification of the lensed galaxy SL2SJ02176-0513, a 10% solar metallicity, 10^8 Msol dwarf with a star formation rate of 10 Msol/yr, combined with ALMA's unmatched resolution and sensitivity, to obtain the first [CII] map of a metal-poor, high-redshift galaxy at ~250 pc resolution. By combining this information with existing 0.20 arcsec-resolution UV and emission line maps from HST, we will verify if and how the [CII] line traces star formation in young galaxies. These observations will provide the first ever spatially and kinematically resolved study of the cold ISM in a low-metallicity galaxy at z~2. This is a re-submission of a scheduled but unobserved Cycle 2 programme. | Starburst galaxies | Active galaxies | 2019-08-29T17:02:33.000 |
| 210 | 2019.1.01702.S | 185 | The physics of the ISM with CO and neutral CI: the final piece | We ask for 27h of Band 5,6 and 7 to follow-up the neutral carbon [CI](1-0) line in an IR-selected sample of 28 galaxies at z=1.1-1.7 (55% on and 45% above the main sequence), and [CI](2-1)+CO(7-6) in a subsample of 20 objects, completing the multi-line survey we have been building since Cyc3. All targets have a CO(5-4) detection and 75% of the sample further has CO(2-1). With the proposed observations we will have up to 5 lines mapping both the cold and warm ISM in normal and starburst galaxies. With such data, we will (i) estimate Mgas with two or even three tracers ([CI],dust+CO(2-1)) and put on solid rock the calibration of [CI] as an Mgas proxy; (ii) map the CO excitation with the critical addition of CO(7-6) tracing the most star-forming gas (totally unexplored for normal high-z galaxies); (iii) derive gas density and far-UV radiation intensity by fitting the ensemble of [CI]+CO+IR emission with PDR modeling; (iv) directly estimate the [CI] excitation temperature from [CI](2-1)/[CI](1-0) and compare it with the dust temperature, a crucial test for the common assumption that dust emission is optically thin in starbursts, affecting the estimate of Mdust (and Mgas). | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2021-07-06T09:31:45.000 |
| 211 | 2022.1.00581.S | 6 | Investigating the impact of the most powerful outflows known | We propose high-angular resolution band-6 observations of the CO(7-6) line and continuum emission in two dusty-obscured quasars at z=2.4. These quasars are currently driving the fastest, most massive ionized outflows at galactic scales known so far with velocities up to 7000 km/s. Observations with a spatial resolution of ~850pc will enable us to map the dense molecular gas and dust in the quasar host galaxies and test whether the fast outflows really deplete gas and dust in the nuclear region within 2 kpc from the supermassive black hole (SMBH) as expected by recent cosmological simulations of galaxy formation. The CO(7-6) observations will also be used to quantify the impact of outflows on the gas kinematics and SMBH growth. Given the remarkable outflow properties evidence for feedback in action should be observed in these pilot quasars. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-06-26T22:24:28.000 |
| 212 | 2013.1.00120.S | 12 | Dense Gas and Chemistry in the Super Star Cluster Environment of NGC 5253 | Nearby starbursts are forming super star clusters (SSCs), which in many respects appear to be newborn globular clusters. The super star clusters are expected to profoundly influence gas in their immediate neighborhood. Under such hostile conditions, one cannot expect star formation (SF) to proceed in the same fashion as it does in the Galaxy today. It is vital to characterize how SF does occur since every galaxy --- including our own --- goes through an epoch of globular cluster formation. The goal of this project is to use ALMA's great increase in sensitivity to investigate the properties of the natal dense gas toward the extremely young super star cluster forming dwarf, NGC 5253. NGC 5253 hosts the nearest (D = 3.5 Mpc), newborn (<2 Myr old), massive SSC. We propose to map the dense gas tracers, HCN(1-0), HCO+(1-0), CS(2-1 & 5-4), the photon dominated region tracers C2H(1-0 & 3-2) and the shock tracers SiO (2-1 & 5-4) and HNCO(4_04-3_03 & 12_012 - 11_011) on 60 pc scales. The maps will be used to characterize the location, amount, density and chemical properties of the dense gas that form and are influenced by these massive clusters. | Galaxy chemistry, Dwarf/metal-poor galaxies | Galaxy evolution | 2016-04-06T14:35:44.000 |
| 213 | 2023.1.01268.S | 0 | Multiscale Magneto-Gravitational Configurations From Filaments to Hub | Hub-filament systems (HFS) are suggested as a key transition stage between interstellar filaments and protocluster/massive star formation. Magnetic fields are believed as one important factor in the formation of these systems. However, since the associated physical process in HFS occur in a wide range of physical scales, it is challenging to probe a complete picture of the multiscale magnetic fields within HFS. In this project, we propose band 6 ACA+12M-array continuum polarization observations toward a HFS NGC 2264 with existing JCMT POL-2 data. The three data set can probe the magnetic fields with a resolution of 0.1-pc (JCMT), 0.05-pc (ACA), and 1000-AU (12-m), corresponding to the filament, hub/core, envelope scale. Hence, the obtained data are essential to establish a complete picture of the multiscale magnetic field within an HFS. This will answer the exact role of magnetic fields in the evolution from interstellar filaments, to massive hub, to young stellar systems. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-01-20T01:15:57.000 |
| 214 | 2019.1.00756.S | 17 | Resolving the first extragalactic low-metallicity high-mass protostellar disk system with ALMA | We propose to observe the accretion disk associated with HH~1177: the first, and so far only, observed jet from an extragalactic high-mass young stellar object. We will observe the HH~1177 powering source in both dust continuum and line emission to quantify the dust mass and kinematic structure of the Keplerian toroidal structure around the accretion disk. By comparing HH 1177 (located in the Large Magellanic Cloud) to Milky Way counterparts as well as to our simulations of accreting, jet-launching massive young stars, these observations will allow an unprecedented analysis of the effect of low metallicities and low dust content on the formation of massive stars. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2021-09-21T00:00:00.000 |
| 215 | 2011.0.00142.S | 0 | Imaging the Birth Ring of the AU Mic Debris Disk | Observations at millimeter wavelengths are unique for imaging debris disks because the emission is dominated by grains of large size that are minimally affected by stellar radiation and winds, and therefore trace best the dust-producing parent planetesimals as well as features resulting from the gravitational perturbations by planets. Here we propose to use ALMA to image the millimeter emission (band 6, Extended configuration) from the edge-on debris disk around AU Mic, an M-type star located at 10 pc, to reveal its hypothetical "birth ring" of planetesimals and examine its relationship to the tiny grains the dominate scattered light images. AU Mic offers a unique combination of proximity, edge-on viewing geometry, and extensive multi-wavelength archival data (including optical intensity and polarization imaging from the Hubble Space Telescope that reveal arcsecond scale features) that make it an extremely compelling testing ground for the "birth ring" theory and the origin of debris disk substructure. If the theory explaining the scattered light surface brightness profile is correct, then the proposed observations will resolve a belt of millimeter emission with outer extent 30 to 40 AU (3 to 4 arcsec), marking the source of the debris. It is also possible that these observations could show clumps or asymmetries indicative of the influence of an unseen planet. | Debris disks | Disks and planet formation | 2013-10-04T20:31:00.000 |
| 216 | 2013.1.00226.S | 39 | A survey of deuterium chemistry in protoplanetary disks | Protoplanetary disks links protostars and Solar System bodies physically and chemically. Deuterium fractionation is one of the most common tools to probe how these different stages are connected. Deuterium fractionation in molecules can for example be used to infer the importance of cold chemistry for different volatiles in the Solar System, including the Earth's sea water. The utility of deuterium fractionation as a probe is currently limited, however, by few, and seemingly contradictory observational constraints on the deuterium chemistry in disks; the spatially resolved fractionation pattern seems radically different both between molecules and between the two most well-studied disks, TW Hya and hD 163296. We propose to carry out a modest (6 source) survey of deuterium fractionation in disks that span a range of stellar and disk characteristics to explore (1), the variability in deuterium-enrichments during planet formation, and (2), the link between this variability and disk structures, ages, and impinging radiation fields. This would provide the strongest constraints to date on how the deuterium chemistry evolves between the protostellar stage and the mature Solar System. | Low-mass star formation, Astrochemistry | ISM and star formation | 2015-12-17T00:00:00.000 |
| 217 | 2019.1.00397.S | 158 | [OIII] 88 Line Observations of Four Remarkably Luminous Galaxies at z ~ 9 - 10. | Recent ALMA observations have demonstrated that the [OIII] 88 micron line is particularly useful to identify galaxies in the reionization epoch even at redshift (z) beyond 9, most of which comes from our team (e.g. Inoue et al. 2016 Science, Hashimoto et al. 2018 Nature). Here we propose ALMA Band 7 observations of four remarkably luminous z ~ 9 - 10 candidates targeting the [OIII] 88 micron line. These four best candidates are carefully selected from all the available galaxy candidates taken from several surveys. Given their bright nature, these objects represent the most chemically evolved system when the Universe age was only ~ 500 Myr. We aim to identify their specroscopic redshift through [OIII]. Owing to the bright nature of the targets, our observations will also detect their dust continuum (rest-frame 90 micron) even in the case of non-detection of the line, which will be important constraints on dust production, growth and destruction mechanisms. Thus our ALMA observations will open the door for characterization of metal/dust enrichment in the heart of reionization era. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2021-02-06T14:25:39.000 |
| 218 | 2023.1.00202.S | 0 | A detailed map of the variation of density, temperature and photo-dissociated gas across the Carina Nebula | The physical connection between star formation activity and the availability of dense gas to feed that stellar formation at a given time is of critical importance for our understanding of how stars form. We propose to use ALMA Band 3 to perform high spatial resolution observations of the densest gas toward two different zones in our nearest extreme massive star formation, the Carina Nebula Complex (CNC). Our selected molecular line transitions which include N2H+, 13CO, C18O, C17O, CH3CN and CN, will provide valuable information about the range of gas densities traced by each of this tracers, the temperature and level of photo-dissociation of the material in two regions with extremely different exposure to massive stellar feedback. This proposal is part of an ALMA observational campaign aimed to investigate the connection between the cloud internal structure, physical properties of the gas and the ability of the CNC to form stars. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-05-06T20:10:18.000 |
| 219 | 2018.1.00332.S | 1 | Revealing the Jupiter shaping Vega's planetary system through ALMA astrometry | Extrasolar Jupiter analogs at a few AU gravitationally dominate the dynamics of planetary systems, influencing the outcome of planet formation. They are most common around massive A stars with planetesimal belts, where unfortunately the radial velocity (RV) technique is least sensitive. We here propose a multi-Cycle monitoring campaign of Vega to astrometrically detect the exo-Jupiter responsible for shaping the double-belt architecture of its planetary system. Astrometry is the only way to detect Jupiters at a few AU in the face-on Vega planetary system, and Vega is best suited for such an experiment with ALMA. With three short repetitions per Cycle, in 4 years we will be able to detect the stellar astrometric signature induced by any of the giant planets directly imaged in other planetary systems around massive stars with planetesimal belts. Through this project, we will demonstrate ALMA's unique capabilities for astrometric planet detection around the brightest, nearby massive stars avoided by Gaia. | Debris disks, Exo-planets | Disks and planet formation | 2021-07-08T14:26:31.000 |
| 220 | 2019.1.01437.S | 216 | An ALMA-TESS study of UV heating in protoplanetary disks | Here we propose a coordinated ALMA-TESS program to study the variability of temperature sensitive lines in an object that is known to have substantial changes in UV emission due to accretion variability: GM Aur. We propose for a total of 9 hrs to observe the 12CO, 13CO, and C18O lines daily over 18 days. We request that these ALMA data be coordinated with TESS observations that have been already scheduled. Using TESS we will be able to track changes in the accretion rate with a cadence of 30 min. The accretion rate in young stars, and particularly GM Aur, is known to be variable and linked to UV emission. UV photons should play an important role in heating the disk. If we detect variability in CO emission lines with ALMA that is coordinated with accretion variability seen with TESS, this would be the first direct link between UV emission and the heating of gas in a protoplanetary disk. | Disks around low-mass stars | Disks and planet formation | 2021-07-01T00:00:00.000 |
| 221 | 2022.1.00911.S | 32 | Resolving the emission of organic molecules in outer Galaxy star-forming regions | The outer Galaxy, i.e. the region of the Milky Way outside the Solar circle, was believed to be an environment not optimal for the formation of molecules and planetesimals because of the low metallicity. Now we are discovering that small, terrestrial planets are omnipresent in the Galaxy, and that molecules, including complex ones, are found in star-forming regions of the outer Galaxy too, although their formation and survival should be different from the inner or local Galaxy due to the very different environmental conditions. It is thus crucial to observe outer Galaxy star-forming regions to constrain models adapted for low(er) metallicity environments, and set the outer boundaries of the so-called "galactic habitable zone". We plan to map at high-angular resolution the abundance of the organic species formaldehyde (H2CO), methanol (CH3OH), and cyclopropenylidene (c-C3H2) towards WB89-670, a star-forming region located in the far-outer Galaxy, at Galactocentric distance of 23.4 kpc. The goal is to understand the relation between these molecules, all crucial for pre-biotic chemistry, at low metallicity, and in an enviroment with C/O ratio a factor 3 lower than Solar. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-01-11T14:16:35.000 |
| 222 | 2021.2.00159.S | 37 | Investigating molecular gas properties in AGNs with strong ionized outflows | AGN-driven outflows are one of the best tracers to study AGN feedback in action since they are thought to regulate star formation in host galaxies by removing, heating or disturbing molecular gas. Here we propose CO(J=2-1) and rest frame 1.3mm continuum observations of 15 local AGNs (z<0.2), which are characterized by strong ionized gas outflows based on [OIII] 5007 line. We performed sub-mm continuum observations using JCMT/SCUBA-2 and measured IR-based SFRs of these AGNs from SED fitting. With stand-alone ACA observations, we will 1) measure the total mass of molecular gas, 2) improve SFR measurements using 1.3mm continuum flux in SED fitting, and 3) search for potential targets of AGN-driven molecular gas outflows by detecting broad wing component in CO(J=2-1) line. We will compare molecular gas mass and star formation efficiency of the targets with normal star-forming galaxies and discuss implications to AGN feedback, especially the delayed AGN feedback scenario. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2023-09-09T10:18:52.000 |
| 223 | 2016.1.01541.S | 90 | Feeding the protoplanetary disk: resolving the 1000 au kinematics | This project aims to map the velocity field of the cold infalling gas in the CO freeze-out regions at radii larger than the Keplerian disk. Current ALMA sensitivity enable us to study both the kinematical and chemical structure at scales >1000 AU. The paths that the gas and dust take on their way to the disk are crucial in determining the survival fraction of the chemical complexity in the large-scale envelope. The cold gas tracers used are sensitive to both the density and temperature gradients present at large-radii. We propose to map L1527 and L1489 using DCO+, N2H+ and N2D+ in bands 3 and 4. The program is aimed to study the kinematics in the regions where CO is frozen out. Thus, infalling structure as determined in CO may not be the complete picture. A complete picture of the motion at these scales will enable us to beetter understand the reservoir of cold gas and dust that can survive on their way to the disk. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-01-30T18:00:39.000 |
| 224 | 2023.1.00449.S | 0 | External irradiation in T-Tauri star ISO-Oph2 | The thermal balance of the outer regions in protoplanetary discs, where the bulk of the mass is stored, includes heating from the interstellar radiation field. Its relevance depends on the UV luminosity of nearby stars and on the abundance of very small grains, or polycyclic aromatic hydrocarbons (PAHs). It is usually neglected in the evolution of T-Tauri stars. The disc of ISO-Oph2 is particularly interesting, as the morphology of the ALMA continuum is suggestive of edge-on external irradiation by HD147889 (B2IV,B3IV). Here we consider the hypothesis of external irradiation in ISO-Oph2, and propose a measurement of the dust temperature. A confirmation of external heating in this case-study, with external irradiation at an angle that is favourable to its identification, would suggest that the thermodynamics in the outer discs of T-Tauri stars may be dominated by external irradiation at any illumination angle. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 225 | 2017.1.01666.S | 13 | Mapping the Molecular Outflow of NGC1068 | In Cycle 3, we observed the central few parsecs of the active nucleus of NGC~1068 and discovered a high-velocity (+/- 400 km/s) outflow in the molecular tracers CO 6-5 (80~mas beam) and HCN 4-3 (150 mas beam). The observations essentially rule out the classic "donut" paradigm for the medium that obscures our sight-line to the broad line region. Rather, the geometry appears to be more of a bipolar outflow resembling the molecular outflows of protostars. However, the outflow is only marginally resolved, making it impossible to discern the dynamical nature of the outflow. We therefore propose to observe the outflow at the best angular resolution afforded by ALMA, 20~mas (1.4 pc), in the CO 2-1 and HCN 3-2 lines. The proposed observations will provide the best possible constraints on the kinematics of the outflow, and in addition will afford the best constraints on the conditions in the near-AGN molecular gas on parsec scales. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-12-18T19:36:23.000 |
| 226 | 2019.1.00837.S | 8 | Constraining the Vertical and Radial Structure of the Turbulence around DM Tau | Turbulence is a fundamental parameter in models of grain growth and planetary evolution and while observational constraints are challenging, our initial studies of the disks around TW Hya and HD 163296 have demonstrated the ability of ALMA to tightly constrain turbulence. Recently, using CO(2-1) data from our ALMA cycle 4 program, we have found significant non-zero turbulence in the disk around DM Tau. This is the first detection of turbulence within our sample, but our knowledge of its radial and vertical structure is limited by the fact that CO(2-1) is most sensitive to gas in the upper layers of the outer disk. We propose to build on our turbulence detection with observations of N2H+(3-2) (sensitive to cold gas near the midplane where CO is frozen out) and CO(6-5) (sensitive to warm gas higher in the disk and closer to the star than CO(2-1)). This combination of emission lines will provide an empirical measure of the vertical and radial structure of turbulence, as well as a more complete understanding of the physical source of the turbulence, the role of turbulence in planet formation, and the outward transport of angular momentum. | Disks around low-mass stars | Disks and planet formation | 2023-10-03T17:45:43.000 |
| 227 | 2021.1.00602.S | 146 | Probing the star formation process and dark matter halos of superthin galaxies | We here propose to map the molecular gas in a complete sample of nearby massive superthin galaxies. Superthin galaxies are spiral galaxies that exhibit extraordinarily large disk axial ratios (>10) and no discernible bulge component. The formation of such object in the hierarchical LamdaCDM context is not well understood, and these observations will shed light on two of the biggest ongoing controversies. Firstly, we will determine the efficiency of star formation in such systems. They are predicted to form stars very efficiently thanks to the low dynamical stability of their gas discs (caused by the razor thin nature of their stellar discs), but yet have somehow retained their gas and low surface brightness stellar discs for a Hubble time. Secondly, we will dynamically determine the shape of the dark matter halo profile in the inner parts of these objects, which are expected to be extremely dark matter dominated. In summary, a short investment of ALMA time will allow us to probe the impact of stellar structure on star formation, and reveal the dark matter halo properties of these enigmatic objects. | Spiral galaxies | Local Universe | 2023-01-27T22:02:42.000 |
| 228 | 2018.1.00215.S | 622 | The sequential star formation towards the IR bright rim of an HII bubble | Despite that optical and infrared (IR) surveys have found active formation of young stellar objects around extended IR bubbles, the details of how the impulse-driven molecular clouds form and how they subsequently fragment and form dense star-forming clumps/cores are not yet clear. IR bright bubble rim N2 is an ideal region for a pilot study on the star formation correlation with the feedback from a morphologically associated OB cluster. Our recent single-dish observations indicate chemical evolutionary sequence towards the dense molecular clumps along this expanding shell of the HII bubble. Aiming at improving our understanding of the star-forming scenario towards these clumps, we are proposing for (1) characterising the multi-scale physical structure and searching for the proof of dynamically evolutionary sequence, by resolving the clumps with the dense gas tracers and the continuum emission at 2 and 3 mm; (2) giving the constraints on the evolutionary status of each clump, by tracing the warm/cold gas and the outflow(s). Comparing with the "spontaneous" star-forming regions, we will test whether triggering or the gravity compress leads to the star formation towards N2. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-12-24T00:00:00.000 |
| 229 | 2018.1.00908.S | 30 | 1 kpc Imaging of z~6 Quasar Host Galaxies | Recent ALMA [CII] and dust imaging of a sample of z>6 quasar host galaxies at high spatial resolution (~0.25", ~2kpc at z~6) reveal a surprising range of morphologies and kinematics. The distribution of gas around these accreting ~10^9 M_sun black holes encodes critical information on the assembly history of these early massive structures that is otherwise inaccessible. Capitalizing on previous low-resolution ALMA observations we request 1 kpc resolution (~0.15") [CII] and dust continuum imaging of a [CII] flux-limited sample of z>6 quasars. This unparalleled dataset will differentiate between dispersion-dominated compact vs. rotation-dominated extended vs. tidally disturbed [CII] emission, and will pin-down the frequency of merging events in z>6 quasar hosts. They will also provide spatially resolved star formation and gas surface densities and address if the hosts form stars at the Eddington limit. Together with the derived dynamical masses of the hosts (needed to constrain the M_BH/M_dyn ratios) the observations will provide crucial constraints to simulations of the first massive galaxies in the Universe. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2020-12-31T18:43:03.000 |
| 230 | 2015.A.00025.S | 9 | Identifying the Host of the Fast Radio Burst 121102 | Fast radio bursts (FRBs), millisecond radio pulses of extragalactic origin, are an unresolved puzzle in astronomy, with more theoretical models than detected bursts so far. With VLA observations, we have just achieved the first interferometric localization of an FRB and identified the host radio counterpart, which is not detected in archival or survey observations at optical, infrared, or X-ray bands. We propose ALMA observations to identify the nature of the counterpart and discriminate between a starburst galaxy, an active galactic nucleus, or something else. A host identification will constrain the distance and energetics of FRBs and thus help identify the underlying engine. DDT observations will be close in time to our VLA detection and a rapid assessment will guide future observations. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-04-19T19:58:13.000 |
| 231 | 2013.1.01022.S | 0 | Mass Accretion onto the Super Massive Black Hole of M 87 | We put same abstract in the first page of Scientific Justification with larger font size and a figure. -------------------- Background: The rate of mass accretion onto Super Massive Black Holes (SMBHs) is an essential parameter for active galactic nuclei (AGNs). Goal of this Observation: With new ALMA polarization capabilities, we will derive the Faraday Rotation Measure (RM: which is a tracer of column density) towards M 87 with 10 times better accuracy compared to our SMA pre-study. M 87 is a representative radio loud AGN. Scientific Impact: With 10 times more accurate RM, we will determine the mass accretion rate for the first time, while our SMA pre-study only allowed us to set an upper limit. It will enable us to discriminate accretion flow models and give us a unique opportunity to investigate the energy source of the jet (e.g., accretion or black hole spin). Why ALMA cycle 2?: We need to investigate polarization properties in the vicinity of the beam center, but with high sensitivity (0.015 mJy/beam at Q and U) in band 3. Our sensitivity requirements can be only achieved with ALMA. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-01-11T00:00:00.000 |
| 232 | 2017.1.00737.S | 32 | Disks, winds, and tori -- towards a comprehensive view of the AGN environment with VLTI and ALMA | We explore the origin of dusty molecular outflows in AGN by combining data from the highest angular resolution IR and sub-mm facilities VLTI and ALMA. Using VLTI we recently showed that the "dusty torus" region is much more complex than models assume: Radiation pressure may drive a clumpy wind that forms a polar outflow. This outflow seems responsible for the bulk of the mid-IR emission seen on <10 pc scales of nearby Seyfert galaxies and may be the origin of kpc-scale molecular outflows invoked in AGN feedback. While this disk+wind picture emerged from detailed VLTI observations, it lacks an exploration of its physical implications: dense molecular gas orbits the black hole and dense clouds are ejected into the outflow. In this pilot study we will observe NGC 3783, the poster child of the pc-scale "dusty outflows", by mapping the kinematics of high-density tracer lines HCN(4-3), CO(3-2) & CO(4-3), CS(7-6), and HCO+(4-3). Do we see the dense rotational disk? Can we prove a significant outflow? And does the IR dust emission trace the high-density regions? These questions can only be solved directly with the unprecedented exploitation of maximal angular resolution of ALMA and VLTI. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-12-19T18:19:13.000 |
| 233 | 2017.1.01359.S | 72 | Unifying Stars and Gas in Quasar Hosts at z~3 and the Co-Evolution Picture | The physical mechanism of the black hole (BH)-host galaxy co-evolution is one of the most important questions in astrophysics. We propose to extend and complete observations of a unique sample of quasars at z~3, the peak epoch of the active galactic nucleus accretion history. Their host galaxies differ by ~1 dex in their stellar masses M* compared to the BH mass and show significantly different narrow-line region properties traced by their OIII luminosity. These quasars are drawn from 70 quasars whose hosts are studied with Subaru AO-assisted imaging. We detected stellar hosts for 4 and estimated upper limits for the other 3 targets proposed here. By extending our sample to much lower BH masses, these systems can serve as a testbed for the co-evolution mechanism. We will test whether a larger amount of gas is present in the more evolved hosts and hence the expected extreme CO luminosities that will allow spatially and dynamically resolved CO line observations similar to our Cycle 3/4 programs. Together with our M* estimates/limits, we will use the gas and dynamical mass estimates to trace their past and possible future evolution onto the established local BH-host scaling relations. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-02-13T18:14:17.000 |
| 234 | 2017.1.00114.S | 14 | Probing low-mass star formation in the CMZ in Sgr B2 Deep South | Star formation in the Galactic center is lower than expected given the high mass of dense gas in the central molecular zone (CMZ). The physical conditions required to drive star formation are therefore clearly different in the CMZ than in the local Galactic disk: overall gas temperature, pressure, and density are much higher. We propose a survey of the only known region of ongoing, widespread star formation in the CMZ, Sgr B2 Deep South (DS). Sgr B2 DS is part of the broader Sgr B2 cloud, but unlike the famous cluster-forming sources Sgr B2 M and N, DS has an extended filament containing hundreds of star-forming cores. We will measure the masses of pre- and protostellar cores down to 0.3 solar masses, deep enough to measure the turnover point of the core mass function. This measurement will provide the best sample for quantitative comparison between Galactic disk and CMZ star formation, thereby establishing an empirical foothold for extrapolation to more extreme conditions in other galaxies. | High-mass star formation, Low-mass star formation | ISM and star formation | 2020-01-22T23:13:28.000 |
| 235 | 2016.1.00065.S | 78 | Probing the dense gas with HCN(5-4) in four SPT lensed dusty star-forming galaxies at 2.5<z<4 | The prodigious star formation rates observed in dusty star-forming galaxies at high redshifts require the presence of significant amounts of dense (>10^5 cm^-3) molecular gas. It is not known, however, whether this is due to such systems simply having very large overall molecular gas masses, or whether in fact their dense gas mass fractions are unusually large. Here we therefore propose to observe the HCN(5-4) transition -- a bona fide tracer of the cold and dense gas associated with star forming cores -- towards five lensed DSFGs at z=2.5-4.0, selected from the South Pole Telescope (SPT) sample. The sources were selected so as to have existing observations (CO(2-1), CO(4-3), CO(7-6), [CI](1-0), [CI](2-1), [CII]). With these data, we will: 1) infer the relationship between dense gas and star formation, as traced by HCN(5-4) and IR luminosity, in extreme starburst at high redshifts. 2) compare HCN with other tracers ([CI], CO) to determine the density distribution of the gas; 3) check the concomitance between dense and diffuse gas in our targets; 4) search for additional dense gas tracers (HNC(5-4), CN(4-3), HCO+(5-4), CS(8-7)) in the same spectral windows. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-03-08T15:58:17.000 |
| 236 | 2019.1.01182.S | 192 | Surveying Triangulum with the ACA: A Key Perspective on Molecular Clouds at High Resolution | We propose ACA 7m observations of the inner disk of M33, completing a partially executed ACA project (2017.1.00901.s).By combining ACA-only observations with an in-hand map of the galaxy using the IRAM 30m telescope, we will achieve a high quality map with 7" = 25 pc linear resolution that observes CO(2-1). Our previous work demonstrates the success of the observing strategy and the scientific promise of executing this survey. These data will be combined with HST maps of clusters and dust extinction and VLA HI observations at the same resolution. These Band 6 observations offer two main opportunities: (1) simultaneous imaging of12CO along with 13CO(2-1) and C18O(2-1) and (2) high velocity resolution observations of molecular clouds. Combined with an excellent suite of ancillary data we will: (1) probe cloud evolution using CO line ratios, (2) identify the scales on which gas transitions from ordered (large scale) to random (small scale) motions and (3) localize the CO-dark gas implied by previous large-scale studies. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2021-03-12T16:29:36.000 |
| 237 | 2012.1.00326.S | 0 | ALMA counterpart identifications of VLA/Herschel-faint AzTEC sources; exploring the redshift distribution of SMGs beyond z=4 | Submillimeter-selected galaxies (SMGs) are thought to play an important role in the formation of giant ellipticals. Despite their huge infrared luminosities and star-formation rates (SFR), the true redshift distribution of SMGs remains a mystery. Recent studies have revealed ‘high-z’ tail, at z > 3, exploiting counterpart identification methods for SMGs with the deepest radio and mid-infrared (MIR) data. However, those SMGs with radio and MIR counterparts comprise only 60–70% of all detected SMGs. We can expect that the remaining 30-40% are located at z > 3 − 4 and that these SMGs are the progenitors of giant ellipticals discovered at z ~ 2. We propose ALMA Band-6 imaging of 30 promising high-z candidates, selected at 1100 μm in an AzTEC/ASTE confusion-limited survey of the Subaru/XMM-Newton Deep Field/Ultra-Deep Survey (SXDF/UDS) in order to pinpoint their positions accurately. The target galaxies do not have robust/tentative counterparts in deep VLA, MIPS and IRAC data, and they are also faint at Herschel wavelengths. Therefore, they are likely to be SMGs at z > 4, although other possibilities exist, including: (1) some of them result from the blending of multiple sources, and (2) they are rather lower-redshift (z ~ 2) sources with lower dust temperature ( ~ 20 K). Via the proposed observations we can determine accurate positions for SMGs, and explore their multiplicity. With accurate positions in hand, we can determine the photometric redshifts of these SMGs using the deep multi-wavelength data in SXDF and confirm how many SMGs are located at z>4. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2015-01-21T10:35:00.000 |
| 238 | 2016.1.01279.S | 68 | MAGNUM FEAR: Magnum Follow-up Exploiting ALMA Resolution. | AGN-driven outflows are believed to be signatures of feedback in action on the host galaxies of accreting BHs. Outflows are observed both in molecular and ionised gas but their acceleration mechanisms are still debated. There are indications that they represent two phases of the same outflowing medium, with molecular gas accounting for most of the mass, but their physical relation is almost completely unknown. We have recently started the MAGNUM project, a survey of nearby Seyferts aimed at a detailed study of the effects of AGN activity on their hosts. The high intrinsic spatial resolution (10-100 pc) combined with the VLT/MUSE field of view and spectral coverage allows to study outflow properties with unprecedented detail. We propose ALMA follow up observations in CO(2-1) to detect molecular outflows and to compare their physical properties with those of the ionized outflows, at the high intrinsic spatial resolution allowed by the closeness of the targets. This is the first study of this kind that will critically constrain the origin of outflows and the impact on host galaxies in low luminosity AGN and that will serve as a laboratory for higher luminosity but more distant AGN. | Outflows, jets, feedback | Active galaxies | 2018-03-13T17:49:47.000 |
| 239 | 2023.1.00412.S | 0 | The Serpens-Aquilla Disk and Multiplicity Survey | We propose a survey of 168 protostars in the Serpens-Aquila star-forming region at 0.09" (~40 au) resolution in Band 7. We will characterize the multiplicity frequency, companion separation distribution, protostellar dust disk masses, and dust disk radii for the largest sample of protostars (besides Orion) within 500 pc. The origin of disks and multiplicity are rooted in the earliest stages of star-formation, but only three sizeable regions have had their protostellar multiplicity and disks characterized (Perseus, Orion, and Ophiuchus). Previous surveys discovered a bimodal distribution of companion separations and it is important to determine if this is `universal'. Similarly, disks emerge early, yet it is unclear if the protostellar disk mass and size distributions are similar across all star-forming regions. This is important given that protostellar disks (as an ensemble) are found to be 5-10x more massive than Class II disks. This survey is essential to test whether or not protostellar disks and multiplicity have similar properties across distinct star-forming regions, implying similar physical processes. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2025-08-26T23:05:38.000 |
| 240 | 2016.1.01005.S | 14 | Characterising the putative dust trap in the pre-transitional disk of V1247 Ori | One of the major unsolved problems in the field of planet formation is the radial drift barrier, where dust grains acquire a very high inward drift velocity and drift into the star before they are able to grow into planets. One possible solution is dust trapping, where the dust particles get trapped in a pressure bump that might be triggered by planets or deadzones. Our ALMA Cycle3 40mas-resolution imaging of the pre-transitional disk of V1247 Ori revealed an inner ring and a sharply-confined crescent structure, constituting a prime-example for a dust trap. In the gap between the inner ring and crescent structure we detected in scattered light an intriguing sprial-arm structure that might be related to the accretion stream of the planet that is also triggering the dust trap. We propose ALMA follow-up observations at longer wavelengths (band 4) to reveal the expected dust grain composition differences between the crescent structure, the gap, and the inner disk. Detecting these opacity differences would provide the ultimate confirmation for the existence of dust traps and enable the detailed characterisation that is necessary to identify the triggering mechanism of the dust trap. | Disks around low-mass stars | Disks and planet formation | 2018-10-23T22:16:23.000 |
| 241 | 2011.0.00454.S | 0 | (Why) Is CenA a source of Ultra High Energy Cosmic Rays: Shock acceleration, jet and UHECR composition | Ultra High Energy Cosmic Rays (UHECRs) are protons or nuclei with energies in excess of 4x10^19 eV (a few Joules). The Pierre Auger Observatory has revolutionized astronomy with UHECRs: precise arrival directions and large samples of UHECRs (which suffer the least deflections in magnetic fields) finally allow studies of the source population(s). There is a statistically significant excess of UHECRs detected in the direction of the nearest radiogalaxy Cen A; this is not hugely surprising as radiogalaxies have long been suspected as the source of UHECRs. Many uncertainties remain including UHECR composition, their acceleration mechanisms, and the (multiple?) source populations. We propose to study the dynamics and physical conditions of one confirmed and five probable molecular clouds in the halo of Cen A (probable remnants of the accreted spiral galaxy) which shock and deflect the northern radio jet of CenA, and form an optimal breeding ground for UHECRs. Our immediate goals are (1) confirm the presence of molecular clouds; their high metallicities can originate seed heavy UHECRs; (2) ascertain the dynamics and masses of the clouds and thus constrain their origin and lifetimes; (3) from momentum transfer arguments constrain the jet composition (light or heavy); (4) determine the energetics of the shock fronts: are these sufficient to accelerate UHECRs? | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2013-02-14T14:40:00.000 |
| 242 | 2016.1.00798.S | 233 | SUPER-ALMA: gas fractions and depletion timescales in AGN hosts at z~2 | An unbiased study of the gas content of AGN host galaxies is fundamental to: 1) constrain the triggering mechanism of AGN activity; 2) quantify the impact that AGN outflows may have on the gas reservoir of the host. We propose to combine CO(3-2) ALMA observations with our on-going SINFONI/VLT Large Programme (SUPER, 280h) on an unbiased sample of AGN at z~2. While SINFONI allows to map ionised gas kinematics (e.g. [OIII]), the CO(3-2) observations will complete the picture, sampling the molecular gas phase of the interstellar medium. The combination of these ALMA observations with the properties of the AGN (Lbol, Eddington ratios, presence of outflows and their energetics) will allow us to make significant progress in understanding the physical origin of any difference in the gas content of AGN hosts compared to inactive galaxies. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2019-03-14T11:44:01.000 |
| 243 | 2021.2.00011.S | 189 | A Careful Calibration of New Molecular Feedback Tracers in the Early Universe | Recent studies with ALMA have led to a significant leap in our understanding of galaxy evolution in the early universe through the detection of clear signatures of feedback in massive starbursts at high redshift. The now most commonly employed tracer is the OH+ molecule, which now is detected in >20 galaxies at z=2-6. In the majority of cases, these studies show evidence for gas infall or outflows through red-/blueshifted lines and/or P-Cygni/inverse P-Cygni profiles. However, the current studies suffer from some limitations due to issues like line blending and mixing of different transitions, which may require different calibrations. We here propose to improve upon these biases by augmenting an existing study of 15 sources from the ACA to produce a sample with complete coverage of all three ground-state OH+ lines. Through simultaneous fitting of all transitions, we will be able to correct for any blending issues of individual transitions, to compare the optical depth tau_OH+ of all transitions, and to investigate the recently discovered scaling relation between tau_OH+ and the dust temperature - as is necessary to more reliably translate the measurements to feedback properties. | Starburst galaxies | Active galaxies | 2023-12-20T22:42:25.000 |
| 244 | 2018.1.00966.S | 174 | Tracing cosmic-ray ionization rates and fluxes in sub-mm galaxies out to z~6 | Interstellar chemistry is driven by fast ion-molecule reactions, and in molecular clouds the chemical reaction network is initiated primarily by the ionization of H and H2 by cosmic rays. This makes the cosmic-ray ionization rate an important parameter. Particles are accelerated in shocks associated with supernova remnants and stellar wind bubbles, so it is expected that the cosmic-ray ionization rate in a galaxy scales with its star formation rate. By observing OH+ and H2O+, molecules closely linked to ionization, and utilizing chemical models, we aim to constrain cosmic-ray ionization rates in a sample of sub-mm bright galaxies (SMGs), some of the most luminous objects in the Universe. This program extends our cycle 4 pilot study of 4 SMGs at z=2.3 to a sample of 12 SMGs from z=2 to z=6, enabling an investigation of the relationship between cosmic-ray ionization rate and star formation rate. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-12-17T21:13:54.000 |
| 245 | 2015.1.00925.S | 258 | Promoting Diversity: ISM Physics and Star Formation across Different Environments | Mapping molecular gas at individual cloud scales (~50 pc) over a large number of galaxies, sampling the diverse environments within them, is necessary to understand how the formation and disruption of GMCs, the efficiency of star formation, and the coupling of feedback to the ISM depend on local and global conditions, and how these processes affect the overall evolution of galaxies. We request 13.5 hours of ALMA main-array plus ACA+TP to produce deep CO(2-1) maps of nine nearby late-type sub-L* star-forming disk galaxies at ~1'' resolution. Late-type disks are sufficiently CO-bright to efficiently map molecular structures (in contrast to dwarf galaxies) and contain diverse dynamical, chemical, and stellar environments which differ from the standard conditions in high mass L* systems. We will explore the link between the multi-phase ISM, star formation, and feedback across a broad range of environments at cloud scale resolution for the first time, and will produce an exquisite legacy dataset for nearby galaxy studies from the southern hemisphere. | Spiral galaxies, Surveys of galaxies | Local Universe | 2017-11-01T23:18:01.000 |
| 246 | 2016.1.00057.S | 37 | Observing the inner wind of the circumstellar environmnent of EP Aqr. | The CO emission of the oxygen-rich AGB star EP Aqr shows a composite nature, with a broad feature superposed by a narrow central peak. Additionally, it has been shown with emission maps on offset positions, that the source of this peculiarity is extended. Such a dual constitution is a clear indication that the outflow of EP Aqr deviates from spherical symmetry. Four possible scenarios can generate CO lines with such an appearance: A dual wind scenario, a large face-on Keplerian disk, a small edge-on Keplerian disk or a face-on narrow spiral. We aim to investigate the inner wind of the dusty outflow of EP Arq in order to be able to differentiate between these scenarios. Observing the inner winds of an objects showing a clear deviation from spherical symmetry will provide answers to the prevailing local dynamics generating these structures, which in turn will shed light on the morphological 'missing link' between the spherical early-AGB phase and the very non-spherical planetary nebula-phase. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-03-17T11:48:31.000 |
| 247 | 2018.1.00072.S | 31 | The cyanide content of exocomets at the epoch of volatile delivery | ALMA's unique sensitivity has recently enabled the first compositional studies of exocometary belts during the 10-100 Myr epoch when volatile delivery events to inner, dry rocky planets are believed to take place. This has been enabled solely through serendipitous CO detections in studies focused on dust emission. In this proposal, we will begin the characterization of the full chemistry of exocomets through a search for CN gas in the belt around beta Pictoris. Based on careful modelling, CN 2-1 should be the strongest molecular line, after CO, in such belts. It traces the total cyanide (mainly HCN) abundance in cometary ice, and our observations are planned to detect CN even if the beta Pic belt is 3x poorer in HCN (compared to CO) than the HCN-poorest Solar System comet. Consequently, we will be able to conclusively determine whether the cyanide content of exocomets in the beta Pictoris system, where volatile delivery is likely ongoing, is similar or depleted compared to Solar System comets. Given the vital role of HCN for prebiotic chemistry, this measurement is crucial to begin understanding whether delivery events seeding life may be common across emerging planetary systems. | Debris disks, Solar system - Comets | Disks and planet formation | 2020-07-29T23:34:54.000 |
| 248 | 2024.1.00800.S | 0 | On the origin of old warm extreme debris disks: do cold outer dust belts play a role? | Extreme debris disks (EDDs) are rare systems with peculiarly large amounts of warm dust, commonly thought to be the natural byproduct of giant collisions that occur during the final accretion of rocky planets. However, this model explains the existence of the youngest EDDs only, the origin of older systems (>200 Myr, beyond the rocky planet formation era) is still mysterious. A possible alternative explanation for older EDDs is that their warm dust is largely produced by the erosion of icy bodies scattered from an outer planetesimal belt into the inner regions as a result of a dynamical instability. This model, however, requires the existence of an outer cold debris disk, for which we have no information in most known objects. To assess the viability of this scenario, here we propose to use ALMA to search for and constrain the properties of possible cold debris material around 8 relatively old Sun-like stars known to host EDDs. There are several indications that a dynamical instability of giant planets also played an important role in the evolution of the Solar System. Our proposed project has the potential to identify systems that are going through a similar process. | Debris disks | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 249 | 2015.1.00607.S | 1 | Precise Gas Dynamical Imaging of the Most Distant Unlensed Starburst | Cosmological simulations suggest that massive galaxies formed in the densest regions in the early universe, predicting the existence of massive protoclusters of intensely star-forming galaxies at high redshift. We have identified such a unique region within 1.1 billion years of the Big Bang, hosting an extreme starburst and 14 normal star-forming galaxies. This environment is a "smoking gun" for early massive galaxy formation through hierarchical buildup. Advancing upon our highly successful efforts related to this region in cycles 0-2, we here propose to image and model the morphology and dynamical structure of the gas and dust in the central starburst down to individual star-forming clumps on 250pc scales; an order of magnitude improvement upon any previous studies in the z>4 universe. Facilitating the new long baselines of ALMA, this unprecedented study will critically constrain the dynamical origin and distribution of the intense star formation activity, the gas mass fraction, as well as the sub-kpc scale star formation law at z>5. Targeting the most distant unlensed dusty starburst, this detailed investigation will be free of any uncertainties associated with lensing studies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2017-02-25T22:52:29.000 |
| 250 | 2023.1.00169.S | 0 | H2CO as thermometer for young embedded disks | Although evidence has been piling up that planet formations begins when the disk is still forming within its envelope, the physical conditions in these young disks are still poorly constrained. An important parameter is the disk temperature structure as this determines whether giant planets can form through gravitational instability, and sets the composition of the planet-forming material. Observations of C17O toward 5 embedded disks at 0.5" (70 au) resolution suggest that these younger disks are warmer than more evolved disks and have no CO frozen out in the inner 100 au. In addition, there are hints that the temperature already starts to decrease before the envelope has fully dissipated. To provide more detailed constraints on the temperature structure, we propose observations of multiple H2CO lines toward 10 embedded disks (Class 0, I and I/II) in Taurus and Ophiuchus at 0.25" (35 au) resolution. Observations of CH3CN, N2H+ and SO2 will provide complementary temperature measurements. This program will allow us to construct spatially resolved temperature maps, and will provide the first detailed characterization of the initial conditions for disk evolution and planet formation. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 251 | 2022.1.00154.S | 30 | The most compact disks in Lupus: the start of super-Earth formation? | Whereas ALMA has revealed many dust disks with gaps, the majority of dust disks is actually compact (<40 au in radius), but these disks have received little attention to date in ALMA studies and it is unclear if they have gaps. A recent demographic study suggests that there is an anticorrelation in the occurrence rate of compact disks as a function of stellar mass, which was also found in the occurrence rates of Super-Earths at <1 au. This can be understood if compact disks are drift-dominated, which enables Super-Earth formation. In contrast, in the larger disks with gaps and rings the drift has been halted by pressure bumps, due to presence of giant planets at wide orbits. It is currently unclear if such pressure bumps also exist in compact disks, due to planets formed in situ. We propose to observe all unresolved dust disks (<20 au radius) in the Lupus star forming region in 1.3mm continuum at 0.04" resolution, to look for disks with small cavities, to measure the full disk dust size distribution, and to test the Super-Earth formation scenario and feasibility of photoevaporative clearing. This will complete the census of resolved disk observations in Lupus. | Disks around low-mass stars | Disks and planet formation | 2025-02-06T15:09:30.000 |
| 252 | 2019.1.00493.S | 216 | Direct Mass Measurements of Pre-Main Sequence Stars in Upper Sco | Pre-main sequence evolutionary tracks are an essential tool for studying star formation, and are used in many important investigations such as measurements of the initial mass function, the ages of star forming regions, and the disk-mass/stellar-mass relationship. Despite our reliance on these models, there remain major discrepancies between evolutionary track models and the known masses of pre-main sequence stars, in part due to the limited number of sources with well measured masses to use as constraints. Recent work has shown, however, that Keplerian rotation in protoplanetary disks with precise Gaia distances can be used to directly measure the masses of pre-main sequence stars with high precision (to ~1-2%), thereby creating an opportunity to measure precise stellar masses for a large number of pre-main sequence stars. Here we propose to observe a sample of 25 pre-main sequence stars in the Upper Scorpius OB Association in CO (3-2) in order to map Keplerian rotation in their disks, and thus measure their stellar masses. These masses will provide crucial constraints on the pre-main sequence evolutionary tracks, which are so vital to our understanding of star formation. | Low-mass star formation | ISM and star formation | 2023-06-23T23:01:31.000 |
| 253 | 2017.1.00750.T | 195 | Direct sublimation vs. gas-phase synthesis: the missing link in mm/sub-mm cometary science | Comets contain ice, dust and debris left over from the formation of the Solar System. Having remained in a relatively quiescent state ever since, their compositions provide unique insights into the thermal and chemical properties of the protosolar disk and prior interstellar cloud. Detections of complex organic molecules in cometary comae are becoming routine using single-dish mm-wave observations, but the common assumption that these species originate in the cometary ice is largely untested. Our latest chemical/hydrodynamic coma models point to gas-phase chemistry as a possible origin for some of these species. We propose to use ALMA to map the distributions of HC3N, NH2CHO, CH3CN and other molecules (including known extended source species) in a bright target-of-opportunity comet, to reveal whether these species arise directly from the sublimation of cometary ice or whether they are instead synthesized as products of gas-phase chemistry in the coma. In case of only a faint comet in Cycle 5, we will focus on mapping the distributions of H2CO, HNC (and other abundant species) to elucidate the nature of their extended coma sources and compare to previous (limited) mapping results. | Solar system - Comets | Solar system | 2019-10-31T15:24:11.000 |
| 254 | 2019.1.01500.S | 0 | The interplay of magnetic fields with expanding HII regions and its effect on triggered star formation. | Feedback effects regulate the process of star formation, favoring the formation of new stars (triggered star formation) or inhibiting it. Among the different sources of feedback, the expansion of the HII regions around the newly formed massive stars is one of the predominant processes. It has been shown by theory and numerical works that HII regions should have a major impact on the magnetic field features and, in turn, that magnetic fields should have a strong impact on the expansion of the HII regions, and on the formation of new stars. In the present proposal, we want to observe 3 HII regions developing together in the W33-Main clump, at 2.4 kpc from the sun. At large scale, we want to determine the orientation of the magnetic field with respect to the expansion of the HII regions, as theory predicts they should be related. At small scale, we want to evaluate the effect of the expansion of HII regions and of the magnetic field features on the formation of second-generation stars. | High-mass star formation, HII regions | ISM and star formation | 2022-10-15T03:10:41.000 |
| 255 | 2016.1.00517.S | 2 | Hairs of the Circum-Event-Horizon Gas Streams? | We propose the full polarization, band 7 observations towards the Galactic supermassive black hole, Sgr A*. Our main goals are to quantify the time variations of the total intensity, polarization percentage, apparent/intrinsic polarization position angles, and the Faraday rotation measure, on timescales of from a few integration time to hourly timescales. We emphasize that the proposed observing frequencies are the highest possible for the full polarization ALMA observations, which will trace the relativistic accretion flow from the optically thin part of the synchrotron spectrum. Diagnosing the correlations between the time variations of the quantities we measure, will clarify fundamentional properties of the relativistic flows immediately surrouding the event horizon, such as whether some emission is coming from flares, and whether or not the magnetic field configuration is steady during the flares. The observations of rotation measure will constrain the present accretion rate of Sgr A*, and the time variability of the accretion rate. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2018-09-06T17:14:21.000 |
| 256 | 2016.1.00615.S | 24 | Probing Dense Gas Physics in the Most Extreme Southern Molecular Outflow | Distinguishing between Active Galactic Nucleus (AGN) and starburst activity in Ultra Luminous Infrared Galaxies (ULIRGs) is critical for understanding galaxy evolution. While observed high dense gas ratios (e.g. HCN/HCO+, HCN/CS) in AGN hosts are promising diagnostics, their physical interpretation is still unclear. We propose to clarify the origin of these diagnostics, using spatially resolved observations of the dense gas (HCN/HCO+/CS), fast shocks (SiO), and vibrationally excited HCN in IRAS20100-4156, a local ULIRG hosting the most powerful molecular outflow ALMA can see. This will allow us to (i) detect HCN enhancement in the outflows wings, and investigate a shock origin, (ii) detect chemical differentiation in the outflowing gas, (iii) test if HCO+ and HCN trace pre- and post-shocked gas, as suggested for Mrk231, and thus study the evolution of dense gas in the outflow. We will also constrain the physical conditions in the dusty nucleus using vibrational HCN lines, and the contribution of mid-IR pumping to HCN enhancement. This study will lead to a significantly improved understanding of how global dense gas properties relate to physical processes in the interstellar medium. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-01-28T08:09:54.000 |
| 257 | 2015.1.00182.S | 12 | The Vega debris disk: narrow ring or broad belt? | We propose to determine the distribution of mm grains (and, by implication, the parent planetesimals) in the Vega debris disk. Interferometric observations to date have not been able to detect the dust, and single-dish photometers reach somewhat contradictory conclusions: some indicating the presence of clumps, others not. Surprisingly, far-IR images show a much larger smooth structure, thought to be tracing small grains being blown out. But overall the results are inconclusive, which, for the eponymous Vega excess star, implies a big gap in our knowledge. Debris disks seem to be of two types, either a narrow ring (the more common structure, implying the presence of shepherding planets), or a broad belt (a more unusual type, suggesting no large planets). Taking existing Vega data seems to suggest (by inference) that Vega has a broad belt. But we don't really know. With ALMA data we can say for sure which is the case, and hence make major progress in understanding the dust dynamics and architecture of the first Vega excess star. | Debris disks | Disks and planet formation | 2018-03-24T15:31:27.000 |
| 258 | 2019.A.00015.S | 52 | Having a ``Rosetta Stone'' for galaxy formation studies in the early Universe | We propose observations of the [OIII] 88 micron emission line for an H-drop Lyman break galaxy with ALMA. The galaxy was found in the UltraVISTA near-infrared deep imaging data in the COSMOS field. We performed an H-dropout selection to find objects at z>13. After careful examination of non-detections in the deep optical to H-band images as well as a flat spectrum from K-band to Spitzer IRAC [3.6] and [4.5]-bands, only one candidate remains. The absolute magnitude of this object is as bright as -23.4 and the best photometric redshift is estimated at z=13.7. The number density of such a luminous object is actually consistent with the (no-)evolution of the bright-end in the UV luminosity function from z~10 recently reported. A successful detection of the [OIII] line from this object will yield a new redshift record. The proposed observations are required to be executed in Janurary or March to meet the JWST proposal deadline on May 1st. The earliest possible timing to observe a real z~14 galaxy with JWST must be beneficial to the broad astronomical community. This galaxy will be a ``Rosetta Stone'' for galaxy formation studies. #The exact object coordinate will be set in Phase 2. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-12-23T17:20:44.000 |
| 259 | 2022.1.00578.S | 10 | A detailed SZ study of a massive z=1.58 merging cluster | Cluster mergers play a fundamental role in the evolution of galaxy clusters. Obtaining a comprehensive understanding of these dramatic events will require extending our observational window to high z, when mergers have a profound impact on the evolution of the observational and physical properties of galaxy clusters. For this reason, we propose to obtain the first high-resolution observations of the Sunyaev-Zeldovich (SZ) effect in the direction of the galaxy cluster XDCP J0044.0-2033, among the most massive known merging systems ever observed at a redshift z>1.5. Through a joint SZ/X-ray analysis, we aim at performing a detailed reconstruction of the thermodynamic properties of the system, practically unexplored at this redshift and at this angular resolution. This will allow for gaining an unprecededent insights into the processes shaping galaxy clusters in the earliest phases of their formation. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2024-01-27T11:17:30.000 |
| 260 | 2019.1.01136.S | 130 | Resolving the rapid quenching of star formation in the local Universe | One key problem in galaxy evolution is how and why galaxies stop forming stars. However, the exact mechanisms that lead to the disruption of the gas supply and the timescales involved are still poorly understood. Post-starburst galaxies are an ideal laboratory to study the galaxy transition process as they have undergone a recent, rapid shutdown in star formation, and are expected to be devoid of cold gas. Surprisingly, many of these galaxies still host large reservoirs of molecular gas, which challenges our current picture of quenching. Recent studies of these galaxies suffered from an aperture bias - we know rapid quenching of star formation occured in some regions but we only have unresolved measurements of the molecular gas. We propose to map CO(1-0) emission at 2.5" resolution matched to optical integral field spectroscopic data from the MaNGA survey in 13 post-starburst galaxies. We will determine whether a low gas fraction in post-starburst regions is the cause of quenching, or if gas is forming stars inefficiently. Only the combination of ALMA and optical IFU observations can reveal what processes are responsible for stopping star formation in galaxies. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2021-04-08T20:16:01.000 |
| 261 | 2013.1.00902.S | 12 | Probing the complex organic reservoir in protoplanetary disks | The composition of ice mantles on dust grains in protoplanetary disks sets the final molecular composition of planetary atmospheres and objects such as comets. An open question is the origin of complex organic molecules in planetary systems, considered necessary for building prebiotic molecules. Methanol is the first 'rung' on the 'ladder' of molecular complexity and is formed within ice mantles on dust grains. In disks, it is released into the gas via desorption triggered by UV radiation. We propose to observe rotational line transitions of gas-phase methanol in a sample of nearby gas-rich protoplanetary disks. The detection of methanol will confirm, for the first time, the presence of a complex organic ice reservoir in a protoplanetary disk, significant because planetesimals begin to form within the ice reservoir in the disk midplane. The selected transitions are the best candidates available across all current ALMA observing bands. Our sources are those which have water vapour detections and/or show strong formaldehyde line emission. This proposal utilises the superior sensitivity of ALMA Cycle 2 capabilities which are absolutely necessary for detecting weak line emission. | Disks around low-mass stars, Solar system - Comets | Disks and planet formation | 2016-06-25T00:43:47.000 |
| 262 | 2023.1.00108.S | 0 | Testing the vortex hypothesis in a protoplanetary disk | The HD 34282 protoplanetary disk hosts an azimuthal asymmetric structure at ~100 au in mm continuum emission revealed by ALMA observations. Intriguingly, the structure roughly coincides with a one-arm spiral in near-infrared scattered light. Simulations have shown that both are signatures of a vortex. HD 34282 is thus a rare system with a vortex candidate revealed in both scattered light and in dust emission. We will test the vortex hypothesis for the structure by examining two theoretical predictions of vortices: 1) smaller dust traced at shorter wavelengths is less concentrated azimuthally than larger dust traced at longer wavelengths, and 2) dust at the center of a vortex can reach a maximum dust size one order of magnitude or more larger than that in the background ring. Specifically, we will carry out sensitive continuum observations with high resolutions at 4 bands, and constrain the dust properties in the disk via multi-wavelength spectral energy distribution modeling. We will also compare the azimuthal extent of the structure at multiple wavelengths. This program has the potential to provide the most definitive verification of a vortex in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2024-12-29T04:31:01.000 |
| 263 | 2015.1.00028.S | 16 | The role of infrared radiative pumping for molecular gas emission in AGNs | We propose to obtain HCN/HNC/HCO+ J=1-0 and J=8-7 line data of the ultraluminous infrared galaxy (ULIRG), IRAS 20551-4250, which contains a luminous obscured active galactic nucleus (AGN) and shows detectable vibrationally-excited (v2=1f) J=3-2 and/or J=4-3 emission lines of HCN and HNC in our ALMA Cycle 0 and 2 data, thanks to small molecular line widths. The estimated high excitation temperatures between vibrationally-excited (v2=1) and vibrational-ground (v=0) levels at J=4 and 3 for HCN and HNC meet the conditions that an infrared radiative pumping mechanism could play an important role. By extending to widely separated J-transitions, we will be able to quantitatively better understand how infrared radiative pumping affects to molecular line flux ratios, when compared to collisional excitation alone, in this unique ULIRG. ALMA's high-spatial-resolution (<1.0") is crucial to probe only AGN-affected molecular gas emission at galaxy nuclei. Our observations will provide invaluable information to interpret molecular line flux ratios in dust/gas-rich AGN-starburst composite ULIRGs from local to distant universe, whose ALMA observations will routinely be made in the near future. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2017-06-27T04:43:59.000 |
| 264 | 2016.1.00549.S | 21 | The Water Snowline in Solar Mass Stars | The location and evolution of the midplane water snowline in planet-forming disks is considered a key factor influencing the outcome of planetary system formation. Yet the location of the midplane snowline has not been determined outside of our solar system. We propose to detect and characterize the snowline (water condensation front) in protoplanetary disks around solar-mass stars. We will use the high sensitiviy of ALMA to measure the velocity profiles of water emission lines that originate in the deep water reservoir inside of the snowline. We will target disks with high mass accretion rates, which are predicted to have the largest snowline radii and therefore the greatest water emission line flux. Modeling of the velocity profiles will allow us to determine the outermost emission radius (due to freeze-out of water vapor) and hence the location of the snowline. | Disks around low-mass stars | Disks and planet formation | 2018-06-26T17:46:27.000 |
| 265 | 2011.0.00403.S | 0 | Mapping the Distribution of Warm Molecular Gas in Arp 220 | Recent Herschel observations of the nearby galaxies M82 and Arp 220 show unambiguously that the high-J rotational transitions of CO (> J = 5-4) trace very warm molecular gas with a kinetic temperature > 500K. This warm component of the molecular gas dominates the luminosity and the cooling. However, Herschel cannot spatially resolve the extent, structure, and kinematics of this warm molecular gas. We propose to map the distribution of warm molecular gas in Arp 220 with ALMA using the CO J = 6-5 line. This line falls in band 9, which can provide a spatial resolution of 0.2'' in the extended configuration, adequate to resolve the two nuclei of Arp 220, which are separated by 1'', and the dust emission, which has an extent of 1.2''. Our Herschel observations indicate that the emission from the warm molecular gas and dust is predominantly coming from only one of the nuclei. Our science goals are to determine (a) unambiguously if the dust at these wavelengths is really dominated by a single thermal component, (b) the extent of the warm molecular gas, (c) accurately the source size, which will tightly constrain the mass of the warm gas, and (d) the presence of structures on scales > 0.2''. Arp 220 is one of the most important templates for high-z SMGs. Therefore, fully characterizing the physical state of the gas and dust is extremely important for understanding the observations of high-z SMGs. Using the continuum mode, the line and the continuum can be mapped simultaneously. Identifying the source of the bulk of the warm gas and dust emission is possible with ALMA early science for the first time (and does not require the full ALMA array). | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2014-01-24T18:55:00.000 |
| 266 | 2018.1.01201.S | 81 | The origin of large-scale gas spirals around a T Tauri star | While gravitational instabilities may regulate angular momentum transport and facilitate the formation of companions in protostellar disks, it has commonly been thought that protoplanetary (Class II) disks have insufficient mass for gravitational instability to occur. In Cycle 4, we serendipitously discovered spiral arms in 12CO emission extending out ~1000 AU from the T Tauri star RU Lup. Although RU Lup is a Class II disk, its spiral arms, in conjunction with its non-Keplerian gas kinematics and large, irregular light curve variations observed over the past century, suggest some kinship with the younger, embedded FU Ori stars, which have large-scale CO structures and extreme magnitude variations that have been attributed to gravitational instability. To assess whether gravitational instability can also create the spiral arms in RU Lup, we request deep observations of 12CO, 13CO, and C18O to develop a more accurate picture of the emission morphology and to derive the gas mass of the disk. Confirmation of gravitational instability in a Class II disk for the first time would reshape our assumptions about the later stages of disk evolution. | Disks around low-mass stars | Disks and planet formation | 2020-02-21T20:57:48.000 |
| 267 | 2018.1.00103.S | 42 | Formation of Large Carbon-Based Molecules in the Red Rectangle | The Red Rectangle is a remarkable pre-planetary nebula. Centered on a binary system, it consists of a dust and molecule-rich equatorial disk, irradiated by strong UV photons, and a X-shaped axisymmetric structure, tracing the bipolar outflow and shaping the nebula in its characteristic rectangular shape. Besides its morphology, the Red Rectangle is best known for the richness of its spectra in the optical and IR. In particular, it displays bright polycyclic aromatic hydrocarbon (PAH) emission, and series of prominent emission bands from 5000 to 7000 Å with wavelengths and profiles that closely correspond to four Diffuse Interstellar Bands (DIBs). We here propose to probe the chemistry of the Red Rectangle by taking advantage of the sensitivity and spatial resolution of ALMA. The main goal is to obtain a census of the molecular complexity in this source by tracing the small-scale chemical variations from the central regions to the outflow. By comparing molecular variations in the Red Rectangle with the distribution of the PAHs and the DIBs, the observations will constrain the conditions in which the complex carbon-rich molecules that carry the DIBs and the PAHs are formed. | Post-AGB stars, Evolved stars - Chemistry | Stars and stellar evolution | 2021-05-11T19:32:04.000 |
| 268 | 2022.1.01213.S | 88 | The Pre-stellar Core Mass Function in a Weakly Magnetized Cloud | Star formation is a fundamental process for the cosmos, but with many open questions. There is no consensus on a general theory that can predict the stellar initial mass function (IMF), from given initial conditions of gas clouds. Development of such a theory requires testing by observations that span a range of environments, yet which are still able to resolve the individual units of star formation: self-gravitating gas cores. Here we propose to carry out an investigation of a protocluster gas clump Center Nest 1 (CN1) within the Vela C giant molecular cloud (d = 0.9 kpc) that appears to be weakly magnetized, since it shows a local maximum of sub-mm polarization angle dispersion. In particular, we aim to measure the core mass function (CMF) from sub-mm dust continuum observations and the pre-stellar core mass function (PSCMF), by utilizing N2H+ and its deuterated form N2D+. The results will be compared to similar studies that have already been performed in a strongly magnetized environment in Vela C. This is a resubmission of an ongoing Cycle 8 program. The targets have not yet been observed. We are resubmitting the proposal to complete the program. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2024-05-18T16:54:55.000 |
| 269 | 2016.1.01345.S | 50 | Investigating a Young, Extreme High-Mass Star-Forming Region | We have recently observed G23.33-0.30, an extremely energetic high-mass star-forming region, with the Green Bank Telescope. This source contains the brightest NH3(3,3) maser ever detected, probably generated by a powerful outflow, and the largest NH3 line widths detected outside of the Galactic Center. G23.33-0.30 coincides with an infrared dark cloud and CORNISH detects no HII region near its position. Given G23.33-0.30's large thermal line widths, bright NH3(3,3) maser, suspected high velocity outflows, and nondetected H II region, this likely indicates that G23.33-0.30 is an extremely massive young stellar object in a very energetic early evolutionary stage. High-mass stars pose the largest challenges, both observationally and theoretically, thus the study of this source will shed light on the formation of the most massive stars in the Galaxy. To study G23.33-0.30's core-scale kinematics and outflows, we request 2 hours in the C40-2 configuration at Band 6. | High-mass star formation | ISM and star formation | 2019-05-22T00:00:00.000 |
| 270 | 2015.1.01125.S | 18 | SMC B1 #1 is the New Perseus: The Relationship Between Av and CO at Low Metallicity | We propose to map the quiescent, low metallicity molecular cloud SMC B1 #1 in 12CO, 13CO and C18O (2-1) with ALMA Band 6 at 1" resolution (0.3 pc in the SMC). We will combine these CO observations with Av maps at matched 1" resolution from Hubble Space Telescope imaging. The 0.3 pc comparison between CO and Av will let us answer key questions about the effect of metallicity on the structure and physical properties of molecular gas. We will measure the Av where CO becomes bright, constraining models for ``CO-dark gas. In addition, we will compare the CO-Av relationship in SMC B1 #1 to (1) what is observed in Milky Way clouds at matched physical scales and (2) what is predicted by simulations of low metallicity cloud structure. With the combined power of ALMA and HST, SMC molecular clouds can be studied as if they were Perseus or Taurus, providing an unprecedented view of molecular gas under low metallicity conditions. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2017-08-04T17:19:02.000 |
| 271 | 2015.1.00405.S | 50 | Physical drivers of the H2/HI ratio in extremely gas-rich, star-forming galaxies | We propose to use ALMA to measure the molecular hydrogen content and kinematics of 5 unusually HI-rich galaxies at z~0.2. These are drawn from the HIGHz survey, which includes not only the highest-redshift detections of HI emission to date, but also some of the most HI massive disk galaxies known in the local Universe, with HI-to-stellar mass ratios up to 190%. Despite having huge HI reservoirs and low stellar surface densities, which might be suggestive of giant, inert disks below the threshold for star formation, HIGHz galaxies are forming stars at higher levels than a typical main-sequence galaxy of the same stellar mass. These systems seem to challenge the pressure model for star formation, but are missing the key information on their molecular gas content. With ALMA we will be able to quantify the partition of hydrogen between its atomic and molecular phases, hence gaining crucial insights into the physics that regulates the star formation in the very gas-rich regime that is thought to be more common in the high-redshift Universe. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2017-06-13T22:37:13.000 |
| 272 | 2012.1.01108.S | 0 | Evaporation process of circumstellar ices probed by embedded YSOs in the Large Magellanic Cloud | Infrared observations have suggested that the bulk of heavy elements reside in the ice mantle in a circumstellar environment of embedded young stellar objects (YSOs). Then, how does the protostar affect the properties of circumstellar ices? Although ices are an important reservoir of heavy elements and complex molecules, it is still open how molecules in the solid-phase return to the gas-phase. A key to understand gas-grain interaction is the evaporation of ice mantles. Shimonishi et al. (2010,2012) newly identified more than 20 embedded massive YSOs in the Large Magellanic Cloud by the near-infrared spectroscopy with AKARI satellite. The author discovered a strong anticorrelation between the column density of ices and the luminosities of massive YSOs based on the spectral analysis of ice bands. The study suggested the evaporation of circumstellar ices as a function of stellar infrared luminosities. We here propose to make ALMA band 7 observations of CH3OH (7-6) and HCO+ (4-3) emission lines. Methanol (CH3OH) is believed to be produced mainly by the solid-state reaction in the ice mantle. Thus the presence of methanol in the gas-phase indicates the evaporation of ices. On the other hand, high-velocity component of HCO+ line is often used to probe the outflow. Our infrared study of ices around LMC’s YSOs has suggested that YSO’s luminosity is a key observational factor that dominates the ice evaporation. We aim to investigate two possible mechanisms of the ice evaporation, stellar radiation and shocks, by investigating the evaporated gas-phase molecules and shock tracers. The proposed observations should put a strong constraint on the mechanisms that return solid species to the gas-phase. | Astrochemistry, Magellanic Clouds | ISM and star formation | 2015-03-20T15:16:41.000 |
| 273 | 2015.1.01232.S | 14 | Revealing the Shock-Interacting Molecular Gas toward the Magellanic Superbubble 30 Doradus C | Supernovae (SNe) have profound influence on the evolution of the ISM, high-energy emission, and efficient acceleration of relativistic particles via shock interaction with ambient interstellar gas. 30 Dor C is a unique remnant of multiple SNe so called superbubble in the Large Magellanic Cloud, which is known as a bright synchrotron X-ray and TeV gamma-ray emitter. Most recently, we found interacting molecular gas using the Mopra 22-m radio telescope in the 12CO J=1-0 emission line. We could not reveal the detailed structures and the physical conditions because of the poor spatial resolution incapable of resolving the expected clumps. We propose to observe the northwest of 30 Dor C where X-ray is the brightest containing young remnant of SN in the 12CO(J=1-0) line by ALMA in order to resolve the giant molecular cloud into clumps and determine their physical properties interacting with multiple shockwaves. ALMA's unprecedented sensitivity and spatial resolution will allow us to study in detail the CO gas interacting with the "extragalactic superbubble" for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2017-04-21T13:38:20.000 |
| 274 | 2021.1.00700.S | 35 | Survey of Chemical Compositions of Star-Forming Cores Embedded in 70 micron-Dark Infrared Dark Clouds | Chemical compositions around a protostar are known to be different between high-mass and low-mass star-forming cores. In particular, nitrogen(N)-bearing complex organic molecules (COMs) are known to be more abundant around high-mass protostars than around low-mass protostars. However, the origin of the difference is still controversial. To address this issue, we focus on the chemical composition around protostars in the early phases of high-mass star formation, where protostars are still growing up as low-mass or intermediate-mass ones. We propose to observe nine protostellar sources in the early stages of the high-mass star formation, which are recently found in 70 micron-dark infrared dark clouds, with an angular resolution of 0".12. We will compare the observational results with those of the other low-mass and more evolved high-mass star-forming cores and assess whether the N-bearing COMs are abundant in the early stages of the high-mass star formation. Based on the results, we will identify the key factors responsible for the different chemical compositions between high-mass and low-mass star-forming cores. | High-mass star formation, Astrochemistry | ISM and star formation | 2023-09-28T09:34:26.000 |
| 275 | 2024.1.00542.S | 0 | HII Regions and Galactic Chemical Evolution | The present-day chemical structure of the Milky Way disk constrains models of Galactic chemodynamical evolution. HII regions, the sites of recent massive star formation, are a bright tracer of Galactic metallicity structure. Galactic disks are expected to be well-mixed, but recent observations of HII regions in the Milky Way and other galaxies have revealed unexpected azimuthal variations in the metallicity structure of these galaxies. Several competing theories have been suggested to explain these observations, including recent enrichment by massive stars and streaming gas motions associated with spiral arms. We propose to observe isotopologues of CO and CN with the ALMA Compact Array (ACA) toward molecular gas associated with HII regions across the Galactic disk. We will use these data to derive 12C/13C isotopic ratios, which, when compared with the metallicities of the associated HII regions, will allow us to distinguish between the competing theories for the azimuthal metallicity structure. We will simultaneously derive 14N/15N and 16O/18O isotopic ratios, which will further constrain models of Galactic chemical evolution. | HII regions | ISM and star formation | 2025-10-25T16:44:38.000 |
| 276 | 2013.1.00222.T | 4 | Broadband transient jet emission from accreting black holes | In Galactic X-ray binaries, an enormous amount of energy is harnessed to produce powerful relativistic jets. The engine for jet production is a compact object surrounded by an accretion disk, but the production mechanism and many of the jet properties are subjects of debate. In order to constrain the physical mechanisms involved in jet production, we propose Target of Opportunity observations of black hole X-ray binaries in outburst with ALMA. We aim to catch the hard spectral state, corresponding to the unique period when their powerful compact jets are building up. Our objectives are to determine the contribution of the jets to total energetics of the system with ALMA and with already accepted quasi simultaneous observations in radio, optical-infrared, X-ray (Swift, Integral, Suzaku, NuSTAR) and up to very high energy (Fermi). ALMA is the only telescope able to bridge the gap between the radio and infrared frequency ranges with very limited observing time. | Black holes, Transients | Stars and stellar evolution | 2016-10-24T06:25:49.000 |
| 277 | 2015.1.01018.S | 1 | Magnetic Field Structure around a Protostar with Effective Magnetic Braking | We propose polarization observations at an angular resolution of 0.2" (~30 AU) toward the Class 0 protostar B335 to reveal the magnetic field structures in its protostellar envelope on a 100 AU scale. We have been studying the gas motions in B335 with our SMT, SMA, and ALMA observations, and have also computed non-ideal MHD models to explain the observed specific angular momentum profile from 0.1 pc to inner 100 AU in B335. Our results show that B335 has all signs of magnetic braking with its magnetic field aligned with its outflow, no Keplerian disk larger than 10 AU, and removal of angular momentum, as seen in MHD simulations. Therefore, it is a excellent target to study the relation between the magnetic field and gas kinematics. Our theoretical calculations suggest that the magnetic field in the flattened envelope on a 100 AU scale around B335 should show dominant poloidal components with only, if at all, minimum signs of being twisted. By linking the observed magnetic field structures and angular momentum profiles, we are able to measure the magnetic field strength in B335 and study the effectiveness of magnetic braking. | Low-mass star formation | ISM and star formation | 2019-11-21T11:36:50.000 |
| 278 | 2022.1.00204.S | 6 | Chemistry in Feedback Environments in the Early Universe | Feedback is thought to be one of the main processes regulating star formation in its peak phase throughout the history of the universe. We here propose to use the key oxygen hydrides, OH+, H2O+, and H3O+, to probe the molecular ion chemistry associated with outflowing and infalling gas vs. material found at the active sites of star formation in four z>2.5 starbursts. Based on state-of-the art chemical modeling, we will measure abundances and column densities, as is critical to calculate mass/momentum outflow/infall rates and the local physical conditions in the absorbing layers. We will also study variations in the gas density in gas flows vs. systemic gas components, molecular fractions, and fractional ionization. We will link these findings to the star formation rates and their surface densities to search for spatially-resolved correlations. These measurements will be key to understand the nature of the turbulent gas entailed in the large-scale outflows and infall associated with massive galaxies in the early universe in their peak starburst phase, and how they impact the resulting stellar population seen in their present-day counterparts at the end of the mass buildup process. | Starburst galaxies | Active galaxies | 2024-04-21T16:58:50.000 |
| 279 | 2015.1.00777.S | 35 | Witnessing the birth of a planetary nebula | The onset of photoionization, leading to the creation of a planetary nebula (PN) is a key moment that may determine the subsequent morphology and kinematics of the object. However, it is difficult to find a star exactly in this critical phase. IRAS 15103-5754 shows strong evidence that it is the youngest PN known: a) It is the first PN that shows water maser components tracing a high-velocity jet, which includes it in the small group of water fountain stars. b) Its maser components present a Hubble-like flow, indicating an explosive event. c) It is the first PN showing synchrotron emission. d) This non-thermal emission is being progressively suppressed by the growth of the photoionized region. We propose to observe several transitions of the CO molecule to study the mass-loss episodes of this source, as well as the effect of jets and the advance of the ionization front on the morphology, kinematics, and excitation conditions of the circumstellar envelope. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2017-10-20T03:16:29.000 |
| 280 | 2017.1.00508.S | 166 | Investigating ISM Physics at z~6 with Multiple FIR Lines of Newly-Discovered Luminous Galaxies | We propose submillimeter follow-up observations for [CII]158um, [NII]122um, and [OIII]88um emission in three remarkably luminous galaxies at zspec=6.033-6.206, which recently discovered in deep ~430 deg2 optical data of our Subaru/HSC survey. We measure the [OIII]88um/[NII]122um line ratio at z~6 for the first time, and constrain the ionization parameters. We also estimate the [CII]158um luminosity (L[CII]) by detecting [CII] emission, and investigate a L[CII]-Lya equivalent width anti-correlation for our target with the ionization parameter estimates. With these observations, we will explore the physical origin of the [CII] deficit, and discuss a new coherent picture of the ISM properties of high-z galaxies; intense radiation with a high ionization parameter ionizes CII and HI in the photo-dissociation region, decreasing the [CII] emissivity, and increasing the transmission of Lya. Our unique sample allows us to investigate the ISM by FIR emission lines very efficiently, and gives us valuable insights into the ionization state in high-z galaxies. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-05-23T13:31:40.000 |
| 281 | 2017.A.00012.S | 2 | First detection of FeO in the stellar wind of an AGB star | Metal oxides and hydroxides are known to be important precursors for dust formation in the stellar winds of cool stars. Several of them, such as CaO, CaOH, FeOH, FeO, MgO, and MgOH have been searched for since the eighties without success. In August 2015, we observed the AGB star R Dor in band 7. More than 200 lines were identified. On 17/10/2017, we realized that one of the unidentified lines can be attributed to FeO (v=0, Omega=4, J=11-10). If true, this would be the first detection of FeO in a stellar wind. However, a detection of a new species can only be firmly established if several spectroscopic fingerprints are detected. We request to observe 3 rotational transitions of FeO (in the Omega=4 ladder): J=10-9, J=11-10, and J=12-10. These lines have the highest predicted line flux. Since R Dor is variable, we wish (1) to re-observe the J=11-10 transition, (2) to observe 2 other rotational lines almost simultaneously with the J=11-10 line, and (3) these data to be obtained close to our Cycle 5 data (24/10/2017) which trace other important gaseous dust precursors. This DDT proposal can confirm (or refute) the FeO identification, a result important for next observing cycles. | Evolved stars - Chemistry | Stars and stellar evolution | 2018-07-10T03:54:28.000 |
| 282 | 2016.1.01510.S | 52 | Probing the host galaxies of QSOs in the early Universe | We propose ALMA observations of the host galaxies of 4 spectroscopically confirmed z > 6 quasars from VST ATLAS to probe the scale and star-formation levels of the associated host galaxies. By measuring the [C II] and dust continuum emission in these galaxies in the early Universe, these observations will provide invaluable data for studying the environment which facilitates the growth to high masses of SMBHs at such early times. Indeed, our sample from the VST ATLAS consists of some of the brightest known QSOs at this epoch and thus the most extreme in terms of SMBH growth in the early Universe. With these observations, we will constrain the FIR-AGN luminosity ratio, which will provide new insights into the relationship between SMBH growth and star-formation. These observations will form a basis for both a larger sample of the brightest z > 6 QSOs with the future addition of further confirmed VST ATLAS candidates, as well as a basis for future high fidelity JWST programs. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-01-04T15:52:24.000 |
| 283 | 2021.1.00401.S | 16 | Molecular precursors of the RNA-world in planet-forming regions | The most accepted scenario for the origin of life is the primordial RNA world, which considers that RNA molecules were likely responsible for the storage of genetic information and the catalysis of biochemical reactions in primitive cell, before the advent of proteins and DNA. Prebiotic experiments have shown that RNA nucleotides can be synthesized from relatively simple molecular precursors, most of which have been detected in the interstellar medium (ISM). To understand how these molecules are inherited by the newly formed planetary systems (with the potential of triggerring life in them), the chemical composition of protoplanetary disks needs to be fully characterized. We propose to detect for the first time one of the key molecular precursors of the RNA world, hydroxylamine (NH2OH), in a protoplanetary disk performing very sensitive ALMA observations towards V883 Ori. This is the best disk to successfully detect this prebiotic species due to the thermal sublimation of the molecular content from the dust grains induced by a recent accretion luminosity outburst. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-10-07T12:30:58.000 |
| 284 | 2017.1.00033.S | 189 | Caught in the act - the formation of a cluster core at z~4 | If high-z submm sources are the ancestors of present-day elliptical galaxies, we would expect to see clusters of high-z submm sources. We have used the wide-field H-ATLAS survey to look for these clusters, finding 15 candidates, including one with an estimated redshift of 4 that consists of 5 galaxies each with a star-formation rate of ~2500 solar masses per year. We propose to use ALMA in Band 3 to carry out a spectral survey of this system, which will show whether the galaxies are physically associated and determine the redshift of the system. The spectral survey will also produce a deep continuum image of the system, effectively 5-10 times deeper than the Herschel image, which should reveal many more sources and show whether these luminous sources are single objects. By combining the spectroscopy and the continuum image, we will estimate the system's mass and where it lies on the path from proto-cluster to virialised cluster, which is important for determining whether the virialisation process quenches the star formation. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-04-17T08:40:01.000 |
| 285 | 2012.1.01123.S | 2 | Atmospheric chemistry on Venus: Diurnal variation of chlorine species | Understanding the atmospheric chemistry on Venus is important to elucidate the atmospheric evolution of the terrestrial-like planets. CO2 cycle is one of the most important and fundamental processes in Venus atmosphere. It controls the stability of Venus atmosphere, which currently remains a puzzling issue on how to effectively reproduce CO2 from O and CO. It is theoretically predicted that ClOx species play a catalytic role in this process; however, there are no observational confirmations yet on such chlorine radical species in Venus. We propose simultaneous observations of HCl and ClO using the ALMA band-9 receiver. The primary goal of this proposal is to observe the spatial distribution and the characteristics of diurnal behavior of HCl in Venus mesosphere, and to detect day and night variation of ClO abundances with taking the advantage of limb viewing geometry that significantly improves the observation sensitivity to low concentration molecules. HCl is the reservoir of active chlorine, and determination of its accurate abundance is essential to understand the chlorine chemistry in Venus. Recent JCMT observations of the vertical profile of mesospheric HCl have brought a surprising finding that the HCl abundance drops quickly above 80 km whereas the photochemical model calculations predict a more vertically constant HCl profile [Sandor and Clancy, Icarus, 2012]. This implies that there might be more effective photochemical destruction of HCl than the model assumes, or there might be a strong downward flow to dynamically remove HCl from the upper atmosphere. A sensitive mapping of HCl distribution and observations of its diurnal variation will provide new and strong constraints on the chemical transport modeling of HCl, and thus improves the estimate of how much total chlorine exist in Venus. ClO is one of the most effective sources of active chlorine, and its distribution is considered to directly link to ClCOx which are possible key accelerator in the CO2 reproduction reaction. A firm detection of ClO is the first must-do step to establish a better picture of ClOx catalytic reactions. | Solar system - Planetary atmospheres | Solar system | 2017-07-09T00:00:00.000 |
| 286 | 2015.1.00315.S | 58 | The secret lives of BADGRS | We have discovered a very nearby population of extremely blue galaxies with Log M* = 7.5-9.5 Msun and high gas fractions (50-95%) that also have the highest specific dust masses of any local population. They have extended and clumpy starformation and H2/dust ratios over an order of magnitude lower than typical star forming spiral galaxies, depsite reasonably high metallicities (0.8Zsun). Their inferred molecular gas depletion times are ~250 Myr, overlapping with those in LIRGs and ULIRGs but at ×100 lower LIR. Instead, these sources represent a far more common phase of galaxy evolution; comprising more than half the galaxies discovered in the Herschel- ATLAS local volume sample. They are full of paradoxes - dusty but transparent, UV bright but with cold dust and high gas fraction but high enrichment. We will explore their dust properties, CO dark gas components, the effects of cosmic rays on CO, disk stability and conditions for H2 formation. Our ALMA observations will probe diffuse and dense gas tracers and dust emission on GMC scales (~70 pc) revealing the secrets of these gas rich and potentially unstable disks. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2017-12-07T00:00:00.000 |
| 287 | 2013.1.00781.S | 333 | Bright End of Number Counts Revealed by ALMA | We propose 1.1 mm (band 6) observations of 333 bright submillimeter/millimeter-bright galaxies (SMGs) in our AzTEC 1.1 mm source catalogs in three deep survey fields. In the previous observations of SMGs with single dish telescopes, it is highly possible that multiple sources were detected as a single SMG due to the coarse angular resolution (~15"-30"). In our proposed observations, we will obtain the constraints on number counts at bright end with high angular resolution observations (0.5") by separating multiple sources. We will reveal the fraction of multiplicity for SMGs detected in single dish surveys, and create true number counts by using a large sample of SMGs. Our AzTEC source catalog contains the largest number of 1 mm-selected sources to date, and is best suited for studying the bright end of dusty star-forming galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2016-12-02T09:43:12.000 |
| 288 | 2021.1.00364.S | 9 | Pilot study of para-D2H+ in a high-mass clump with ALMA | Chemistry is an extremely powerful tool to estimate the duration of the pre-stellar phase, which in turn is a key ingredient to disentangle among the disntict star-formation theories. The most reliable chemical clock available is the ortho-to-para ratio (OPR) of H2, which however is impossible to measure directly in the cold, prestellar gas. The results of our state-of-the art simulations show that the ortho-H2D+/para-D2H+ ratio is an excellent proxy of the H2 OPR. We hence propose to obtain ALMA observations of para-D2H+ in a high-mass, infrared-dark clump, for which archival data of ortho-H2D+ (ALMA Band 7) are available. The increased ALMA capabilities of cycle 9 make possible to perform this study, which will represent the first interferometric detection of para-D2H+, and the first detection of the molecule in a high-mass star-forming region. By comparing the observational results with MHD simulations, we will provide accurate and reliable estimates of the age of several prestellar cores embedded in an high-mass clump and of the elusive H2 OPR, key to constrain star formation models. | High-mass star formation | ISM and star formation | 2024-07-11T03:58:44.000 |
| 289 | 2018.1.01464.S | 9 | Mapping the ISM in absorption-selected galaxies at high resolution | A key priority of absorption-line research has been to identify and study the galaxies presumed to host the gas dissected in absorption. Despite decades of sustained effort, only a very small fraction of damped Ly-alpha systems (DLAs; defined by HI column densities representative of galactic discs) have been connected to visible galaxies. And, until recently, none have had observations of their molecular gas recorded in emission. In previous Cycles, we have made the first detections of the CO emission from six DLAs at redshifts z=0.1 to 0.8. These data imply remarkably large molecular gas masses (MH2~4x10^9 to 8x10^10) and high molecular gas fraction (f=0.3 to 0.9). The spatial resolution of these data is however very low (20kpc). Here, we request time to map the CO (4-3) emission from 3 of our most gas-rich DLA galaxies at ~kpc resolution to properly dissect the galaxies gas dynamics and study whether the bulk of the gas is in ordered disks or in extended haloes. Furthermore, the comparison between the flux in different CO transitions will allow us test whether the ISM conditions are comparable to that of MW-type galaxies, or whether the CO lines are closer to being thermalised. | Damped Lyman Alpha (DLA) systems | Cosmology | 2021-01-09T12:13:31.000 |
| 290 | 2012.1.00142.S | 7 | Dust structures in the beta Pictoris disk at high resolution | We propose to image the brightest debris disk - beta Pictoris - with ALMA in band 6. The primary aim is to study the distribution of mm-sized dust on scales from ~150AU down to ~7AU, near the planet beta Pic b. This will enable us to delineate the location of the colliding planetesimals - the ultimate cause of the debris cascade in such disks. We will compare this with the distribution of sub-micron grains seen in scattered light, the micron grains seen in the mid-IR and the location of the planet beta Pictoris b The results will be used to test models both of grain physics and of interactions of planets with debris disks. This will be applicable not only to beta Pic itself, but also to debris systems in general. The images will probe the mm-grain population of several intriguing structures, including the 100AU ring, the outer disk, inner clumps, as well as the warp or inclined disk. Simultaneously we will be performing a deep search for emission from the circumstellar CO and SiO in the disk, probing the origin of the gas and the nature of the parent planetesimals. | Debris disks | Disks and planet formation | 2015-02-10T14:13:09.000 |
| 291 | 2023.1.00687.S | 0 | Resolved, Wide Field Maps of Dense Gas Tracers in LMC Clouds | We request 35.6h of main array time to obtain sensitive (30mK) 12m+7m maps of the emission from Band 3 'dense gas tracers' at sub-pc+0.1-0.5km/s resolution across the 13CO-emitting extent of seven molecular clouds in the Large Magellanic Cloud. Our target clouds have existing ALMA maps of CO isotopologues and span a range of star formation activity. We will use the data to study the spatial organization and velocity field of the dense gas within each cloud, the distributions of intensity, linewidth and line profile shape parameters for each tracer, and their relationship to the physical properties of CO- and 13CO-emitting structures. The proposed maps will build a bridge between highly resolved Galactic work and kpc-scale results from more distant systems, a key to understanding the physics that drives extragalactic scaling laws relating `dense gas' and star formation. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2025-11-07T15:41:36.000 |
| 292 | 2023.1.00229.S | 0 | Constraining the gas content and excitation mechanism in the Spiderweb protocluster at z=2.2 | According to the hierarchical merging scenario, mass assembly strictly links to the build-up of large-scale structures. Therefore, constraining the gas content and excitation mechanism of intensely star forming galaxies in galaxy clusters in formation is essential for our understanding of star-formation at high redshift. Recent ATCA observations reported 46 CO(1-0) emitters in the Spiderweb protocluster at z~2.2. Our objective is to constrain the molecular content using CI lines, considering the diverse physical conditions in this dense environment. To achieve this, we propose the ALMA 12m array to observe CO(4-3), CO(7-6), [CI](1-0) and [CI](2-1) of 10 cluster members with both robust ATCA CO(1-0) and ALMA CO(3-2) detections. With the proposed observations, we aim the following: i) derive securely the molecular mass based on two [CI] lines; ii) constrain the gas excitation condition; iii) constrain the infrared luminosity; iv) explore the environmental effect by comparing to the field galaxies at similar redshift. These observations will enable us to constrain the gas content and excitation mode, thus understanding the formation of protoclusters. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-04-09T21:22:14.000 |
| 293 | 2023.1.01604.S | 0 | MIGHTEE-CO: Adding molecular gas to the resolved neutral hydrogen across the past billion years | The balance of neutral and molecular hydrogen, how the components evolve with redshift, and their dependence on galaxy properties, are open questions. The intrinsic faintness of neutral hydrogen (HI) has until recently been the limiting factor in measuring the full gas content of galaxies at cosmological redshifts. With the SKA precursor facility MeerKAT, resolved observations of HI at z=0.08, corresponding to one billion years of lookback time, are now possible. We propose to use the ACA for a pilot programme, to observe the molecular gas via the CO(2-1) emission line in a representative sample of galaxies with resolved HI observations from MeerKAT at 0.04 | Spiral galaxies, Surveys of galaxies | Local Universe | 2025-09-24T10:17:13.000 |
| 294 | 2016.1.00021.S | 17 | Resolving the molecular gas within 100 pc of M87's supermassive black hole | The proximity of M87 (3C 274), the archetypical giant elliptical radio galaxy at the centre of the Virgo galaxy cluster, presents a unique opportunity to investigate in detail the circumnuclear molecular gas revealed first by CO J=1-0 observations with the IRAM 30-m and more recently imaged for the first time with ALMA (this team's Cycle 1 data). The preliminary results from the ALMA data show that the molecular gas is unresolved and resides within 100~pc of the supermassive black hole (SMBH). Resolving the molecular gas for the first time is now possible with ALMA's long baseline capability. We were awarded time in Cycle 3 to do this, but unfortunately observation of the project was not completed and so we wish to resubmit this proposal for Cycle 4. With this Cycle 4 proposal we therefore wish to obtain 0.16'' (~12~pc) imaging of the CO J=1-0 line to unambiguously resolve the molecular gas structures for the first time, allowing us to investigate the nature and origin of molecular gas that resides within the 3.1'' sphere of influence (SOI) of the SMBH in unprecedented detail. | Galactic centres/nuclei | Active galaxies | 2018-10-10T19:03:10.000 |
| 295 | 2012.1.00219.S | 2 | Spectroscopy of a normal star forming galaxy at z=2 with 200 pc resolution: physical conditions in the cold ISM at high redshift | We propose spatially-resolved observations of the CO(3-2) and [CII] lines and 630 GHz continuum emission in the gravitationally lensed galaxy MACS J0451+0006 (J0451). J0451 is a representative L* star-forming galaxy at z=2.01 magnified by a factor of 49 ensuring that ALMA's resolution (0.6 arcseconds) will correspond to a physical scale of only 200 parsecs in the source plane. Our extensive observations with HST and ground-based laser-assisted adaptive optics have yielded precise physical properties (radius, stellar mass, star formation rate, far-IR luminosity, and metallicity) making it the ideal source for detailed ALMA observations. Via this proposal, which represents a natural extension of that approved for Cycle 0, we aim to characterize the physical conditions, spatial distribution, and kinematics of the cold ISM via resolved observations as well as to compare these with our existing optical and near infrared data. Our specific goals are to (1) determine the physical conditions of the cold ISM in a typical z=2 galaxy; (2) determine the mode of star formation (i.e. extended disk vs. compact central starburst) via the distribution and kinematics of the cold ISM; (3) test whether the ratio of [CII] to far-IR emission on 200 pc scales follows the same trend with star formation density as at z=0, and thus to determine its physical origin; (4) compare the spatial distribution and kinematics of the cold ISM (traced by CO and [CII]) with that of bright star-forming regions (traced by Halpha, UV, and far-IR emission) and hence measure the interaction between star formation and cold gas dynamics. As we argued in our Cycle 0 proposal, our observations will provide the first detailed study of the cold ISM in a typical L* high-redshift galaxy, and the first spatially-resolved data necessary to investigate carefully the mode of star formation. Such an investigation would not be possible without the boost in signal and resolution provided by gravitational lensing. An equivalent program targeting an unlensed source would require several days of integration even with the completed ALMA array. J0451 therefore presents an unique opportunity for ALMA to make dramatic progress in the study of the cold ISM in a typical high-redshift galaxy. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2015-07-08T19:27:11.000 |
| 296 | 2017.1.01249.S | 14 | Turbulence -- the missing link between AGN and star-formation quenching? | We will use ALMA in band 3 at 0.2'' resolution to study the CO(1-0) gas kinematics in 3C 326 N at z=0.1, a key target for our understanding of how AGN regulate star formation in their host galaxies. We will also observe CO(3-2) in band 7 to measure the gas excitation, CO-to-H2 conversion factor, and gas mass surface densities. Radiative AGN activity and star formation are so weak in this galaxy that we can witness directly how the mechanical energy of the radio jet is distributed in the gas and radiated away through line emission from shocked gas. If our basic understanding of AGN feedback is correct, then this energy injection should drive a turbulent cascade within the gas, which enhances the global and local turbulent velocities, and hinders molecular cloud collapse and star formation on small scales. With ALMA we will measure the turbulent line widths in the dominant mass tracer in 3C326 N to see directly if turbulence cascades down to scales of individual star-forming regions as commonly assumed by AGN feedback models and observers alike, an assumption which currently has no direct observational foundation. These observations will be accompanied by extensive hydro modelling. | Active Galactic Nuclei (AGN)/Quasars (QSO), Early-type galaxies | Active galaxies | 2019-02-23T14:46:06.000 |
| 297 | 2017.1.01081.S | 112 | Probing the Molecular Gas Dynamics of High-z Quasar Hosts on Sub-kpc Scales | Studying the triggering and fueling mechanisms of quasars at early epochs is essential to understand the co-evolution between supermassive black holes (BHs) and their hosts. Simulations suggest that high-z quasars are triggered by gas-rich mergers or cold-mode accretion in disk galaxies. We propose to investigate the prevalence of mergers versus disk galaxies among quasar hosts by mapping the molecular gas dynamics in eleven strongly-lensed quasars at 130 in BH mass and >150 in gas mass. With the proposed data, we will examine the dynamical properties of high-z quasars at spatial scales of 500pc (source plane). We will constrain their dynamical masses by fitting models to the source-plane reconstructed rotation profiles, and thus evaluate the redshift evolution of the BH-to-galaxy mass ratio. These observations will quadruple the current sample of quasars with sub-kpc scale CO imaging, and thus promise to revolutionize our understanding of the SMBH-host co-evolution. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2019-02-27T00:00:17.000 |
| 298 | 2016.1.01129.S | 3 | Turbulence and Wave Propagation in the Solar Internetwork | We propose observations with ALMA to better understand the processes of energy propagation and dissipation through the magnetized plasma of the solar atmosphere. In particular, we will use the millimeter observations to retrieve information on the temperature fluctuations associated with acoustic shocks, turbulent cascades, and wave propagation in the solar chromosphere. The observed emission measure fluctuations, which are coupled to the local temperature in the solar chromosphere, provide a new diagnostic tool to characterize thermal conditions that is less dependent on interpretation of spectral lines formed in dynamic, non-LTE conditions. This should help clear up a long-standing puzzle related to abnormally high phase speeds in the chromosphere and will also be used to characterize the temporal scales of temperature fluctuations in the turbulence generated by the impulsive energy release by an acoustic shock. The understanding of these mechanisms is an important step in identifying similar processes occurring in other magnetized, turbulent astrophysical plasmas. | The Sun, Evolved stars - Shaping/physical structure | Sun | 2018-08-15T00:00:00.000 |
| 299 | 2018.A.00049.S | 309 | ACA Observatory Project: SMC Band 3 mapping | The SMC is an ideal laboratory to study star formation and evolution in a low metallicity environment similar to the early Universe. During Cycle 5 an observatory legacy project was carried out with ACA 7m+TP aimed at mapping a large portion of ISM 12CO(1-0) and 12CO(2-1) in the SMC northern bar, including regions of peak activity (e.g. NGC 346) as well as more distributed activity and lower gas surface density. We propose to complement the existing dataset with relatively deep observations in the bottom of Band 3 to probe other emission mechanisms that occur in star-formation regions and in stellar ejecta, such as continuum free-free, H recombination lines and molecular lines (including SiO, HCN, HCO+, CS). | HII regions, Magellanic Clouds | ISM and star formation | 2019-09-23T00:00:00.000 |
| 300 | 2017.1.00010.S | 3 | Unveiling the Magnetic Field Structures of Super Star Cluster Forming Clump in NGC 5253 | We aim to investigate the role of magnetic fields in a super-star-cluster (SSC) form- ing clump that we have discovered in the starburst galaxy NGC5253, using polarization observations in Band 7 at 0.06 pc resolution. We also observe high resolution CO observations to resolve the SSC-forming clump, to investigate relation between magnetic field and structure of the clump. NGC 5253 hosts two SSCs with Halpha bipolar outflows in the starburst region. Our ALMA CO data has revealed that a compact molecular clump (HVCC; mass of 10^5 solar masses, radius of 4 pc) sits in the location of one of the SSCs. The HVCC shows a velocity gra- dient in the direction perpendicular to the outflows, which suggests a rotating clump with the rotation axis being in the same direction of outflow axis. We aim to unveil the polarization direction of the SSC-forming clump compared to the rotation/outflow axis, and to determine whether the SSC-forming clump is magnetic-dominant or rotation-dominant. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2019-04-26T17:50:01.000 |
| 301 | 2019.1.01730.S | 24 | Resolved CO Excitation across Nearby Galaxy Disks | We propose simultaneous observations of the rest-frame 345.795GHz CO (3-2) and 356.734GHz HCO+ (4-3) transitions within two selected PHANGS galaxies. We aim to investigate variations of the CO spectral energy distribution in dependence of readily available quantities such as stellar surface density, (molecular) gas surface density or ionization parameter. For both targets we already have a plethora of molecular spectra (CO, HCN, HCO+) on-hand. Inclusion of the proposed lines, will immediately allow us to perform novel radiative transfer models in order to constrain the density and temperature of the molecular gas. | Spiral galaxies | Local Universe | 2021-01-22T16:29:31.000 |
| 302 | 2016.1.00608.S | 17 | The nature and origin of the Solar system scale disk in the Helix Nebula | We aim at imaging the Solar system scale, dusty disk around the central star of the Helix nebula, the closest planetary nebula (PN, d=152 to 219pc). There are two scenarios for its origin: a Kuiper belt that survived the stellar post-main sequence (post-MS) evolution or a remnant post-Asymptotic Giant Branch (pAGB) disk that formed from material ejected by the star during that phase. We will measure the gas content and probe for large grains in the disk in order to distinguish between the two scenarios. The primordial Kuiper belt case: This will be the first Kuiper belt confirmed and imaged around a star that went through the post-MS evolution and critical, direct evidence that planetary systems survive this phase. We will observationally investigate the effects of this phase on planetary/planetesimal systems. The remnant post-AGB disk case: We will measure its gas and dust mass to test predictions of evolutionary time scales of such disks. We will investigate whether second-generation planet(esimal) formation is possible there. Our observations will impact our understanding of the evolution of post-MS stars and their disks and on the binary hypothesis of PN formation. | Debris disks, Exo-planets | Disks and planet formation | 2018-08-10T22:06:06.000 |
| 303 | 2019.1.00419.S | 13 | Mapping the 3D Kinematic Structure of Planet Formation | Substructures observed in both the NIR and mm continuum such as gaps, rings and spirals are highly suggestive of on-going planet-disk interactions. Although other mechanisms have been proposed to create these structures without the need for a planet, in the case of HD 163296 observations of the gas kinematics provide extremely strong evidence that (at least) three planetary companions are present (Pinte et al. 2018, Teague 2018, submitted). Using a recently developed technique to measure the 3D velocity structure from line emission, we have identified the characterisic flow structures associated with planet opened gaps, allowing for the transport of volatile rich gas to the planet forming midplane. We propose for high spatial resolution observations of the J=2-1 transitions of 13CO and C18O to, in concert with previously published 12CO observations, map the 3D gas velocity structure as a function of both radius and height in the disk. These maps will, for the first time, allow us to track the delivery of volatiles from the warm molecular layer towards the planet forming region, and provide a direct comparison for simulations of planet-disk interactions. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2022-07-14T21:53:13.000 |
| 304 | 2015.1.00586.S | 24 | Solving the mystery of star formation without cold gas | This proposal is designed to address a major issue in understanding the ISM properties of low-metallicity starburst galaxies: the lack of molecular gas despite active star formation. Indeed, the molecular gas reservoir is difficult to measure at low metallicity as CO is more prone to photodissociation by hard radiation fields than H2. With vigorous star formation, bright far-infrared lines (including [CII] from our Herschel survey), but little detected HI and CO, the low-metallicity starburst galaxy Haro11 stands as a clear outlier from the Schmidt-Kennicutt relation. Known as a local analogue of Lyman break galaxies, it serves as the template for high-redshift galaxies and it is the best case to study the gas-star formation cycle under such extreme conditions. We propose band 3, 6, and 7 observations of the CO lines to localize the cold, star-forming gas in Haro11 at 1" resolution, probe spatially the gas excitation and physical conditions (densities, filling factors, optical depth, etc.), and determine accurately its total molecular gas reservoir. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2017-08-03T15:27:07.000 |
| 305 | 2017.1.01722.S | 243 | Spectral scans for high CO transition lines in z>6.5 QSO candidates selected from PanSTARRS1 & WISE | In previous ALMA Cycles 3 and 4 we conducted a spectroscopic survey of promising z>6.5 quasar candidates selected by us from PanSTARRS1 3pi and WISE. To identify and measure the redshifts of the candidates we proposed and performed Band 3 spectral scans for redshifted CO emission expected from the quasars host galaxies. In these scans we looked for the redshifted CO(6-5) line in the lower receiver sideband, while the upper sideband simultaneously scanned for the redshifted CO(7-6) line. Using this method, we detected the CO(6-5) and CO(7-6) lines in two of our candidates, and CO(6-5) line in one candidate redshifted to z~7. We are now carrying out optical spectral observations of these candidates. These previous ALMA results prove that our method is very efficient in finding new quasars up to a redshift z~7. Since there is only one quasar known at z~7, ULAS J1120+0641, discovered in near-infrared, our observations would thus significantly contribute to quasar and galaxy formation studies. Here, we propose to continue the survey of high-redshift quasars candidates uniquely selected by us from PanSTARRS1 3pi and WISE. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-02-23T01:02:12.000 |
| 306 | 2021.1.01420.S | 22 | Initial environmental magnetic field and turbulent properties: does it matter to shape the outcome of star formation ? | Observations of magnetic fields, angular momentum, and disks in Class 0 protostars seem to point toward a scenario where the magnetic field plays a dynamical role during the protostellar collapse leading to the formation of stars and their protoplanetary disks. If this scenario is correct, the initial magnetic properties of the cores, inherited from the surrounding material, may have an important role shaping for example the size distribution of protostellar disks. It is crucial to test further this hypothesis by observing protostars sharing well-characterized environmental conditions. We resubmit here our highly-ranked ALMA Cycle 7 proposal, partially observed, to test wether the dynamical role of the magnetic field is linked to its initial topology, in a set of two protostars which share the same genetic heritage, the Taurus twins. Both protostars are embedded together in a rather simple environment, with similar large scale magnetic, and turbulent conditions: the comparison of the magnetic and kinematics structure as observed with ALMA in these two twin cores can be used efficiently to constrain the conditions necessary for magnetically-regulated collapse to develop. | Low-mass star formation | ISM and star formation | 2023-10-05T13:41:10.000 |
| 307 | 2023.1.01524.S | 0 | The Star Formation Quenching ACA Survey of the Local Universe | Star formation quenching is a key process that drive the galaxy evolution. This process might be due to a variety of phenomena (related to the presence of an Active Galactic Nucleus, internal dynamics, or the influence of the environment in which the galaxies live) that are virtually impossible to disentangle without a well resolved, and statistically significant sample of galaxies. Using ACA, we propose to conduct a ACA survey to image, with 12CO(2-1) line emission, 79 targets drawn from the CALIFA sample. All the galaxies are quenching (e.g. "green valley") systems and show specific patterns in which star-forming and retired regions within the galaxies are distributed (e.g. "quenching stages"). By combining ACA data, existing CARMA observations and CALIFA data, we will assemble an unbiased dataset to study the star formation quenching in the Local Universe. We will assess whether variations of star formation efficiencies or molecular gas-to-stellar mass fraction bring galaxies to quiescence. Together, we will use enormous amount of information provided by CALIFA to put stringent constrain on the various star formation quenching scenario proposed in the literature. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2025-06-24T14:34:31.000 |
| 308 | 2012.1.00962.S | 2 | Carbon [CII] on a z=6.027 Multiply-Image Lensed Galaxy Behind the CLASH cluster Abell 383 | A large number of galaxies have been discovered at z>6 using space- and ground-based facilities, the majority of which are very faint in the optical/IR and the detection of Lyman alpha emission to confirm their redshift has been a challenging task. A more complete study of these distant galaxies is needed, given their nature holds clues about the end of the epoch of reionization. ALMA offers new possibilities to study such galaxies via bright emission lines such as [CII]. Here we propose band 6 observations of [CII] in a multiply-imaged lensed LAE at z=6.027, for which high-magnification and detailed lens models enable a comprehensive study of its properties. Our goals are : (i) to use [CII] as a critical probe of the interstellar medium in a z=6 galaxy; (ii) to estimate how effective the line is as a coolant for the ISM, compared to other galaxy populations at similar redshifts based on L_CII/L_FIR ratios, (iii) to place constraints on the total amount of gas in this galaxy by comparing the dynamical mass from the [CII] line width with the stellar mass obtained from the optical data; (iv) to assess whether this metal-poor z=6 galaxy, demonstrates an enhancement of the [CII] emission compared to lower redshift, metal-rich star-forming galaxies; (v) to open up a new window to reveal the nature of these yet unexplored galaxy population, enabling studies of statistical samples and detailed studies with high-resolution observations. This proposal is a part of a large extragalactic Chilean key project with broad community support and national funding, in collaboration with the CLASH science team. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2016-04-22T00:00:00.000 |
| 309 | 2022.1.01473.S | 31 | Identifying the dominant heating source of the interstellar medium in the central 300 pc region of a quasar at z=6 | Observations of high-J CO lines have great potential for tracing X-ray heated gas around an AGN and identifying heavily obscured quasars even at z>6. However, since previous low-resolution observations of multiple CO lines in X-ray quasars suffer from an undesired contribution from an extended kpc-scale starburst of the host galaxies, it was difficult to conclude that X-ray emission is the dominant heating source in quasars. We propose 0.05"-resolution observations of the CO(6-5), CO(8-7), and dust continuum emissions in a luminous quasar at z=6.0, J2310+1855, for understanding the physical properties of the interstellar medium (gas and dust) in the central 300 region. J2310+1855 represents the best sample currently available for the purpose because the CO(13-12) line emission has been detected at the same spatial resolution. We use three diagnostic techniques to separate X-ray heating from other heating mechanisms (star formation, cosmic ray ionizsation, and shock). Once this approach is established, it will be possible to apply it to bright dusty sources that are not detected in X-ray to find heavily obscured quasars. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-07-19T13:05:52.000 |
| 310 | 2021.1.00607.S | 76 | The dense gas star-formation law in dusty star-forming galaxies at z~2-4 | Understanding the physical mechanisms triggering intense star formation in high-z dusty starburst galaxies requires probing the gas in a wide range of environments, including the densest cores of giant molecular clouds. These regions are the main sites of star formation but they remain little studied, especially at high-z, because they are opaque to the brightest, most common gas tracers. Here we propose to characterize the dense gas star-formation law in rapidly star-forming galaxies at z~2-4, by observing two mid-J transitions of HCO+, HCN, and HNC at 0.5-1.0" resolution in four of the brightest, strongly lensed galaxies in the Southern sub-mm sky. The brightness and exquisite ancillary follow-up make these galaxies ideally suited for measuring intrinsic dense-gas line fluxes from spatially-resolved observations. This will provide us with a unique opportunity (1) to determine whether or not high-z starbursts follow the dense gas star-formation law found in less extreme, low-z environments; (2) to measure the dense gas mass fractions and depletion times; and (3) to constrain the local ratios between dense and more ambient gas phases and compare with low-z galaxies. | Starburst galaxies, Gravitational lenses | Active galaxies | 2023-06-23T17:17:45.000 |
| 311 | 2016.1.00376.S | 376 | Surveying the chemical nature of protostars in OMC-2/3 | The chemical diversity of protostars is now well established: hot corinos are rich in saturated organic molecules, while warm-carbon-chain-chemistry (WCCC) protostars are overabundant in carbon-chain species. Did the Solar System experience a hot corino or a WCCC phase during its formation, or neither? To address this question we should target low-mass protostars belonging to massive star forming regions (SFRs), i.e. the kind of environment where the sun most likely formed. With this in mind, we carried out a single-dish survey of the chemical nature of 10 low-mass protostellar cores in the OMC-2/3 filament in Orion, the closest high-mass SFR. After observing lines from CH3OH and c-C3H2 to trace hot corino and WCCC chemistry, respectively, our results suggest hot corinos may dominate. In order to verify this, high-angular resolution observations with ALMA are crucial to disentangle the emission arising in the vicinity of the protostar from that of outflows and external UV-irradiated layers, as well as core multiplicity within each source. The proposed project will provide unprecedented clues regarding the chemical nature of protostars in a protosolar-like environment. | Astrochemistry | ISM and star formation | 2018-06-16T00:52:23.000 |
| 312 | 2013.1.00269.S | 16 | Sgr B2 - The Proving Ground for Star Formation Theories | Sgr B2, a high-mass molecular cloud in our Galaxy's Central Molecular Zone, is the most extreme site of ongoing star formation in the Local Group in terms of its gas content, temperature, and velocity dispersion. If any cloud in our galaxy is analogous to the typical cloud at the universal peak of star formation at z~2, this is it. We propose a 6'x6' mosaic in the 3mm window targeting gas thermometer lines, specifically CH3CN and its isotopologues. We will measure the velocity dispersion and temperature of the molecular gas on all scales (0.02 - 12 pc, 0.5" - 5') within the cloud, which will yield resolved measurements of the Mach number and the sonic scale of the gas. We will assess the relative importance of stellar feedback and turbulence on the star-forming gas, determining how extensive the feedback effects are within an ultradense environment. The observations will provide constraints on the inputs to star formation theories and will determine their applicability in extremely dense, turbulent, and hot regions. Sgr B2 will be used as a testing ground for star formation theories in an environment analogous to high-z starburst clouds in which they must be applied. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-06-07T02:44:17.000 |
| 313 | 2019.1.00590.S | 6 | Building the spatially resolved CO SLED of the most luminous QSO in the local Universe | We propose ALMA Band 3,9 and 10 observations to obtain the first measurement of the CO SLED resolved on 600 pc scales in the hyper-luminous QSO PDS 456 (z=0.185). With a bolometric luminosity of 10^47 erg/s, it can be regarded as a local analogue of the bright QSOs shining at z~2, the peak epoch of QSO luminosity density. Our target shows the most powerful, persistent, X-ray ultra-fast (0.25c) wind revealed so far, and a galaxy-wide molecular outflow able to remove gas more quickly than it is used to form stars. PDS 456 therefore represents a unique target to investigate the effects of AGN radiative output and feedback on the molecular gas properties on sub-kpc scales. We aim to build the spatially-resolved CO SLED of this hyper-luminous QSO by combining the proposed CO J=1-0,7-6,9-8 observations with our Cycle 4 CO(3-2) data which probe similar scales. Comparison of the matched-resolution CO transitions will reveal the distribution and kinematics of cold and warm molecular gas with unprecedented detail. The excitation mechanisms of the CO gas will be studied without the shortcomings (as gravitational lensing) typically affecting the hyper-luminous QSOs at higher-z studied so far. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-10-29T18:23:16.000 |
| 314 | 2013.1.01031.S | 4 | Tracing the reioniation epoch through millimeter spectroscopy | We propose to use ALMA to detect and map the [CII]158micron line in a small complete sample of the most distant galaxies observable from ALMA whose redshift was confirmed through the presence of the Lyman alpha emission line. These galaxies are distributed over the epoch of reionisation of the Universe. In Cycle 1 we obtained time for the first 3 galaxies: data are already available for two of these and one shows a clear detection of the [CII] line at z=7.109. We now ask to observe the remaining two targets. The detection of the [CII] line in these distant galaxies will allow us to address fundamental questions related to their physical nature and will test the recent evidence suggesting that the Universe was still partly neutral at z~7. In particular the goals of our observations are: 1) to determine the neutral hydrogen fraction in the IGM by comparing the redshift of the [CII] line with the Lyman alpha profile that is absorbed by the IGM; 2) to measure the star formation rate independently of the UV and Lyman alpha luminosities which are sensitive to dust; 3) to constrain the metallicity of these primeval galaxies though the possible detection of the FIR continuum. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2016-07-22T09:12:22.000 |
| 315 | 2023.1.01040.S | 0 | Circular Polarization Diagnostics in a Solar Active Region | This is a community proposal from over 20 co-authors to measure circular polarization in a solar active region in Band 3. This is the first cycle in which such observations are possible. Circular polarization is the key diagnostic for measurement of chromospheric magnetic fields with mm observations, and the purpose of these observations is to characterize the polarization properties of features in an active region showing both emerging magnetic flux and a sunspot. In particular, we will measure polarization in transient features in an emerging flux region, study the polarization structure of the chromosphere above a sunspot umbra, including umbral waves, and measure the height of polarization features above a sunspot at the limb. | The Sun | Sun | 2025-07-25T19:24:30.000 |
| 316 | 2019.1.01186.S | 7 | Dense Gas Tracers in Nascent SSCs in the Antennae | The onset of star formation in super star clusters (SSCs) is expected to have a strong impact on the molecular line emission from their natal clouds. Previous studies have shown that changes in the line ratios of dense gas tracers HCN and HCO+ have the potential to track the evolutionary progress of molecular clouds as they begin to form SSCs. To test this potentially valuable diagnostic trend, we need to see if it is replicated in a variety of environments. The overlap region of the merging Antennae galaxies has a significant population of young SSCs at various stages of evolution, including the only confirmed candidate proto-SSC that has not yet begun star formation. This makes the Antennae one of the most promising regions to probe the evolution of the dense gas at these very early stages of SSC formation. The observations proposed here will improve our understanding of the behavior of the dense gas, give insights into the mechanisms by which SSCs form, and calibrate an observational diagnostic tool for future young-SSC studies. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-11-24T10:06:46.000 |
| 317 | 2019.1.00003.S | 40 | Breaking Cosmic Dawn with ALMA | To study details of the epoch of reionization we need to unambiguously detect galaxies that are likely responsible for that process and study their star formation properties. This will be achieved by measuring [CII] line in a sample of z~7 galaxies, highly magnified due to gravitational lensing by clusters of galaxies, yet intrinsically ordinary and selected from our large Spitzer and HST campaigns. All galaxies have spectroscopic detections and measured stellar properties from Keck/HST/Spitzer. We will also compare [CII] and UV/optical emission with predictions from simulations made by our team, and investigate whether the relation between star formation rate and L[CII] differs from the local universe due to modified Kennicutt-Schmidt relation at z~7 or low metallicity. The proposed observations have sufficient resolution and depth due to gravitational lensing to test both scenarios. The velocity offset measurements of Lyman-alpha to the systemic velocity (measured via [CII]) will provide constraints on the properties of the neutral gas within galaxies. This proposal will make ALMA the premiere facility for studies of galaxy formation at the reionization era. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2022-04-21T14:33:59.000 |
| 318 | 2015.1.01580.S | 2 | The Fine Structure of an Extreme, Lensed Starburst Galaxy at z=5.7 | We propose to observe a full diagnostic suite of five far-IR fine structure lines in an extraordinary starburst galaxy at the end of cosmic reionization. Through the power of gravitational lensing, our observations will measure the metallicity, radiation field, density, kinematics, and AGN effects with effective resolution of a few hundred parsecs, which has only been possible to date in the nearest star-forming galaxies. SPT0346-52, at z=5.7, already has high-resolution maps of the dust continuum and low-J CO emission, as well as integrated measurements of mid-J CO, [CII], and full radio-to-IR SED coverage. These observations effectively complement Herschel studies of local ULIRGs, and extend the study of these lines to the first Gyr of cosmic history. The high sensitivity, high resolution studies made possible by ALMA will address several key questions about the first stages of galaxy evolution, including the production of heavy elements, stellar and AGN feedback mechanisms, the energetics of the ISM, and the dynamics of the first galaxies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-03-15T01:36:46.000 |
| 319 | 2019.1.01357.S | 20 | Constraining the H2 Surface Density Profile in IM Lup | Despite being central to the understanding of planet formation theories and protoplanetary disk evolution, the total disk gas mass and its radial surface density profile are poorly constrained. We have shown that CN emission, particularly the N=3-2 transition, offers a solution. Originating from the tenuous atmosphere, the transition is in non-LTE, and thus modelling the observed spectra offers a tight constraint on the H2 gas volume density without the need to assume any sort of rescaling values, as it required for other approaches using CO or HD. We propose for high angular resolution observations of CN N=3-2 in IM Lup, a disk which has been proposed to marginally gravitationally unstable owing to the stunning spiral ring structure observed in the mm continuum. Using our novel approach we will constrain the radial surface density profile of the disk and subsequently limits on the total gas mass, to a) test whether this system is gravitationally unstable and b) demonstrate the viability of a new method to constrain disk gas masses. | Disks around low-mass stars | Disks and planet formation | 2022-05-03T19:16:40.000 |
| 320 | 2017.A.00018.S | 18 | Studying the effects of variable UV heating on the outer disk | Here we propose to use ALMA to undertake the first variability study of UV sensitive lines in the millimeter in an object that is known to have substantial UV variability: GM Aur. We propose for a total of 4.7 hrs to observe the CN and HCN lines daily over nine days. We request that these data be coordinated with approved Chandra-HST-VLA observations to observe GM Aur on Jan 11 and 19; we have also secured simultaneous Spitzer data and ground-based high-resolution NIR spectra on Jan 11 and 19 along with ground-based high-resolution optical spectra on Jan 12 - 18. Specifically, using HST and ground-based optical spectra we will be able to track changes in the UV emisison of GM Aur over nine days. If we detect variability, this would be the first observed link between UV emission and the heating of gas in the outer disk. | Low-mass star formation | ISM and star formation | 2018-09-02T20:04:15.000 |
| 321 | 2018.1.01208.S | 11 | Definite Test of Magnetic Braking in B335 - Imaging Its 10 AU Disk | To observationally study the effects of magnetic field on gas motions in collapsing dense core, we propose to observe the Class 0 protostar B335 in 13CO (3-2) and C18O (3-2) with ALMA at 0.05" (~5 au) resolution to resolve the gas motions in the innermost 10 au region.We have measured the gas motions from 10,000 au to the inner 100 au in B335 with our SMT, SMA, and ALMA observations, and found signs of efficient magnetic braking, namely no Keplerian disk larger than 10 au and removal of angular momentum, as seen in MHD simulations. With the proposed observations, we will reveal the angular momentum transfer down to the inner 10 au region in B335 and measure the size of its Keplerian disk. With these measurements, we will provide the first observational constraint on the efficiency of magnetic braking. If magnetic braking in B335 is actually inefficient, we expect to see dominant rotation in the innermost 10 au region. If it is indeed efficient, we expect the angular momentum profile continuously decreases toward the center. | Low-mass star formation | ISM and star formation | 2020-12-10T17:45:33.000 |
| 322 | 2021.1.00349.S | 12 | Triggering Mechanisms of Quasars and Black Hole Fueling in the Eary Universe | Gas-rich galaxy mergers have long been suspected to trigger quasar activity and provide the fuel for their supermassive black holes (SMBHs). However, observational studies to date, which are predominantly focused on low-redshift quasars at z<2, remain inconclusive about the rate of ongoing mergers in quasar hosts. Making use of a newly discovered population of very young quasars present in the early universe, whose nuclear activity was triggered less than ten thousand years prior to the observations, we aim to address this long-standing debate from a new perspective. These young quasars represent excellent targets for this study, since whatever process triggered their nuclear activity so recently might still be observable today, thus enabling us to probe the very early phases of quasar activity and SMBH fueling. To this end we propose to obtain high-resolution (~0.2") ALMA observations of the luminous [CII] emission for three young quasars at z~6. These observations will allow us to identify any potential traces of an ongoing merger or interaction with a companion galaxy, or search for cold and clumpy gas inflows, which could provide the SMBH fuel in the absence of mergers. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2023-12-28T17:50:06.000 |
| 323 | 2015.A.00021.S | 30 | Sgr A* multi-wavelength monnitoring | The accretion flow onto the Galactic center supermassive black hole (Sgr A*) generates a fluctuating source of e.m. radiation that has been detected at all observable wavelength domains, including radio, submillimeter, near-infrared (NIR) and X-ray. The rapid fluctuations (< 10 min) likely originate in the innermost regions of the accretion flow. Despite many attempts to clarify the correlations between the light curves at different wavelengths through observations with ground-based facilities, there is still no conclusive understanding of the variability. Recently, new pointing models have allowed the Spitzer Telescope to observe Sgr A* for continuous 24-hr periods with a S/N similar to that of ground-based, AO-supported 8-m telescopes. We have successfully organized a major multi-wavelength campaign including simultaneous 24 hr observations with both the Spitzer and Chandra space telescopes in July supplemented with observations from ground-based observatories, including the SMA. With this DDT proposal, we seek to include ALMA for extending the time coverage in the sub-mm, which is a particularly important wavelength regime for constraining the physics of the emitting region. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-09-01T17:30:43.000 |
| 324 | 2023.1.01638.S | 0 | SZ view of the thermodynamic properties of a complete sample of distant, massive ICM-selected clusters | We propose deep Band 1 observationa of the Sunyaev Zeldovich (SZ) effect for a complete SZ-selected sample of massive and distant galaxy clusters. This sample at redshift 1.4 | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2025-10-16T13:24:42.000 |
| 325 | 2013.1.00568.S | 3 | Molecular Gas Dynamics of a Dual-AGN Cadidate - W2332-5056 | We propose to study the molecular gas dynamics within the central 20 kpc of a recently discovered super massive black hole binary candidate W2332-5056 at z=0.3447. A total 2.11 hour, single pointing ALMA observation in band 6, will allow us to probe CO(3-2) kinematics and distribution in the central host, but notably capture the dynamical actions within the central kpc. The observations will provide inimitable dynamical information to test the elusive and rare super-massive AGN binary hypothesis for this system. | Active Galactic Nuclei (AGN)/Quasars (QSO), Spiral galaxies | Active galaxies | 2016-09-23T14:38:25.000 |
| 326 | 2022.1.00746.S | 20 | Follow-up observations of mysterious [CI]-faint gas-rich galaxies | We propose mosaic observations of [CI](1-0) in gas-rich galaxies NGC 6052, NGC 7679, and ESO 467-G027 using both 7-m array and "Total Power Array". Previous 7-m array single point snapshots in Cycle-6 could not detect the [CI](1-0) emission in these galaxies while CO(1-0) emission was detected by single-dish telescopes. However, the reason for [CI](1-0) non-detection by ACA is not clear because two distinct explanations are possible, (1) there are CI-poor/CO-rich environments or (2) [CI](1-0) traces unusually extended gas components (i.e. large missing flux). Our new observations will be able to clearly distinguish these two scenarios. [CI](1-0) is often used to measure molecular gas mass (MH2) instead of CO(1-0), particularly in high-z galaxies. To improve the conversion methods from [CI](1-0) to MH2, it is necessary to understand the reason for the mysterious [CI](1-0) non-detection in the nearby Universe. In addition, this project may be able to show that [CI](1-0)/CO(1-0) ratios would be used to learn new parameters such as starburst age rather than just use it as an alternative mass tracer instead of CO(1-0). | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2024-06-12T20:25:17.000 |
| 327 | 2018.1.00827.S | 15 | Can polarization tell us anything about magnetic fields around young protostars? | Dust polarization is commonly used to infer magnetic fields, assuming that dust grains are aligned with the field lines. These polarization observations are the only way we have to study magnetic fields in regions close to protostars (since Zeeman observations have yet to be conducted at high resolution). Recent observations have shown that 2 other mechanisms, self-scattering and radiative alignment, can be the cause of polarized emission in disks. We originally conducted a Band 7 survey of 10 young protostars in the Perseus Molecular Cloud to test the influence of the magnetic field. Our data show highly significant polarization in all sources at the ~few % level. To disentangle the mechanisms responsible for the polarization signal, we propose a Band 3 follow-up survey of 6 sources. Using the same resolution as our Band 7 data, we will determine if we can use high-resolution polarization observations to probe magnetic fields in disks by observing at longer wavelengths where the dust is optically thin and scattering is expected to be much lower. | Disks around low-mass stars | Disks and planet formation | 2021-06-16T15:36:25.000 |
| 328 | 2017.1.01631.S | 13 | Probing the effects of a tidal encounter on the sub-structure of a protoplanetary disk | RW Aur is a T Tauri star that has very recently undergone a tidal encounter with star B, which is also hosting circumstellar material. This object provides the unique opportunity to explore the impact of a star-disk fly-by in perturbing and disrupting part of the protoplanetary disk orbiting a new born star. Whereas this event is extremely rare in low mass star forming regions, it is expected to occur more frequently in dense and massive young associations, which are however too far for disks to be explored at high spatial resolution. How these impulsive events affect the angular momentum evolution of disks, the accretion rate onto the star and ultimately the planet formation potential of protoplanetary disks is still an open question. In this context, the spectacular RW Aurigae system offers the opportunity of a rare insight into this question. With this proposal we aim to probe the effects of the tidal encounter within the circumprimary and circumsecondary disks, since such interaction is expected to trigger strong perturbations by warping and truncating the disks, and by triggering large spiral arms. | Disks around low-mass stars | Disks and planet formation | 2019-01-22T15:34:02.000 |
| 329 | 2013.1.00740.S | 1 | Unveiling Merger-driven Gas Physics in the Nucleus/Overlap Regions of Mid-stage IR-bright Merger VV114 | Numerical simulations have demonstrated the importance of galaxy mergers in triggering starbursts and fueling the AGN in the host galaxies. An observational test of gas response requires mapping both the diffuse and dense ISM in merging U/LIRGs at high resolution. We obtained ALMA cycle 0 HCN/HCO+/CO data toward the mid-stage merger VV114 in order to test this scenario. From this study, we found an unresolved component which may be surrounding an AGN, and ~10 dense gas clumps associated with extended starbursts. Furthermore, we used a radiative transfer model to characterize the physical conditions across the merging system. However, our data were limited in resolution and we could only derive the gross properties. In addition, our cycle 0 CO image was suffering from severe dynamic range issues, and only the highest peaks were mapped reliably. Therefore we propose 6.4 hours of ALMA Cycle 2 time to map the HCN, HCO+ and CO lines at the highest resolution offered through Cycle 2 (~ 48 pc). Our aims are to identify the dense clumps at GMC-scale, and to clearly differentiate the AGN and SB components using spatial and kinematical information along with radiative transfer models. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2016-11-12T17:48:24.000 |
| 330 | 2016.1.00472.S | 13 | Positioning SiO masers in OH 231.8+4.2. | In the past years, we performed mas-resolution maps of the SiO (7mm) and H2O (1.3cm) maser emissions toward OH231.8+4.2, a bipolar pre-planetary nebulae (pPN) surrounding a binary system. Important clues on the structure and kinematics of the close stellar surroundings of this bipolar pPN were found. H2O masers are found to be distributed in two areas along the symmetry axis of the nebulae oriented nearly north-south delineating a bipolar outflow, and their astrometric positions have been accurately measured. SiO masers, indicating the position of the Mira component of the binary system, form a structure perpendicular to the axis of the nebulae. The general picture of the source is satisfactory, except for the relative position of the two masers. Surprisingly, SiO masers, have been tentatively placed 250 mas away (370 AU) from the apparent center of the outflow. It is of crucial interest to confirm the relative position of SiO with respect to that of the H2O emission. This would give important clues on the origin of the post-AGB ejections and, in particular, on the role of the two components of the binary system in the formation and evolution of the bipolar outflows in this pPNe. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2018-10-18T22:16:02.000 |
| 331 | 2012.1.00474.S | 4 | Understanding nuclear streaming: stellar, atomic and molecular gas kinematics in the inner 100pc of nearby active galaxies | Previous imaging studies by our group and others revealed a correlation between the presence of dusty nuclear spirals (at scales of hundreds of parsecs) and nuclear activity in galaxies, suggesting that such structures trace the feeding flow to the nuclear supermassive black hole (SMBH). Our studies of the ionized gas and hot (2000 K) molecular gas kinematics using integral field units (IFU) in nearby active galaxies, have indeed revealed inflows with velocities of ~50 km/s along the dusty spirals. Nevertheless, the mass flow rates in these gas phases are usually small (10^-5 - 10^-3 solar masses per year) and interpreted to be only the ``hot skin" of a much larger gas reservoir and flow - which should be dominated by cold molecular gas (associated with the dusty spirals). ALMA is the ideal instrument to map both the spatial distribution and kinematics of this cold molecular gas in order to quantify the actual inflows at the same scale probed by the optical and near-IR observations. We thus propose ALMA observations in the CO(2-1) emission line of a sample of 5 nearby active galaxies selected for: (1) having dusty nuclear spirals; (2) their proximity, allowing to resolve tens of pc's at the galaxies (necessary to probe streaming motions); (3) having previous IFU observations (by our group) showing evidence for streaming motions along the nuclear spirals; (4) having previous single-dish CO detections, assuring the success of the ALMA observations. Our goal is to obtain the flux distribution and kinematics of the cold molecular gas within the inner kiloparsec of our sample, at improved spatial resolution and sensitivity relative to previous observations in order to map the molecular gas mass distribution and obtain the overall kinematics and in particular the mass flow rates along the nuclear spirals. | Galactic centres/nuclei | Active galaxies | 2015-09-02T19:44:56.000 |
| 332 | 2023.1.00494.S | 0 | Characterizing the Water D/H Ratio in Orion Protostars: Clustered vs. Isolated Protostars | The water D/H ratio is essential for tracing the origins of water from the interestellar medium to protostars and disks, to comets, and to the surfaces of rocky worlds. Tentative evidence suggests that the water D/H ratio inherited by a protostellar system can be influenced by its formation conditions, whether clustered or isolated. To definitively test whether environment affects the water D/H ratio, we propose to observe 10 low-mass protostars in the Orion molecular clouds, 5 located in highly clustered environments and 5 located in more isolated environments. The sample will more than double the number of low-mass protostars with water D/H ratios and it was chosen based on previously detected emission from complex organic molecules, which is strongly correlated with water emission. We will observe two HDO lines in Band 6 at 225 and 241 GHz, and we will observe the H218O line at 203 GHz in Band 5. We request an angular resolution of 0.15" (~60 au) such that the emission can marginally resolved and spatially associate it with the continuum. Overall the proposed observations will enable us to learn how environment shapes the D/H ratios of inherited molecules like water. | Low-mass star formation, Astrochemistry | ISM and star formation | 2025-08-06T02:51:51.000 |
| 333 | 2012.1.00875.T | 0 | Peak Flux and Frequency of GRB Afterglow | Gamma-Ray Bursts (GRBs) are among the most powerful explosions in the Universe. Understanding the diversity of the astrophysical entities that form GRBs is an ongoing study that represents one of the most pressing inquiries in modern astrophysics. We propose to determine the synchrotron peak frequency (vm) and the peak spectra flux density (F_(v,"max" )) using a monitoring observation (~30 days) at the 345 GHz band. The recent X-ray and optical based follow-up observations of afterglow are causing a reappraisal and expansion of the previous standard view on GRBs and the fireball model. To overcome this situation, the characterization of the synchrotron spectrum detecting with the peak frequency in lower frequency is the key. Specially, submm observations provide “clean” measurements of the source intensity and are unaffected by scintillation and extinction. Determining the shock peak in the sub-mm wavelength and comparing it with those in optical and X-ray wavelengths provides an unambiguous test of the fireball model. This would offer a direct measurement of the circumburst GRB density profile and confirm that the synchrotron emission is a primary contributor to afterglow emissions at lower frequencies. These characterizations are also essential for examining the required additional components to the standard external synchrotron shock model for X-ray and optical emissions. To realize this observation, the ALMA ToO will be coordinated with submm, ground-based optical telescopes, and X-ray observations. | Transients | Stars and stellar evolution | 2015-01-22T09:19:00.000 |
| 334 | 2021.1.01545.S | 27 | Characterizing the physical conditions of star-forming ISM at z=6 | Recent near-infrared spectroscopy studies of massive quiescent galaxies at z=4 suggest that they were formed by z>5 with a strong and short burst of star formation. Submillimeter bright galaxies (SMGs) at z=6 are the most likely progenitors of massive quiescent galaxies at z=4. This proposal requests 6 hours of ALMA time to characterize the physical conditions of the star-forming interstellar medium (ISM) in an extreme starburst galaxy at the reionization epoch. We aim to observe the [CII] 158um, [OI] 145 um, and [NII] 122 um far-infrared (FIR) fine-structure lines. Combining the measurement of the line fluxes with that of [OIII] 88 um and [NII] 205 um in ALMA archival data, we will be able to derive the physical properties of both ionized and PDR gas in the SMG at z=6: 1) gas density in ionized regions, 2) gas density in PDRs, 3) PDR fraction of [CII] emission, 4) ionized/PDR volume filling factor, 5) gas-phase metallicity, 6) strength of radiation field from the line ratios, and 7) dust temperature from dust continuum SEDs. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-02-09T18:15:48.000 |
| 335 | 2018.1.00294.S | 103 | Ionized Gas, Radiation Field, Masses, and Dust Temperature in Forming Massive Clusters in the NGC253 Starburst | Our ALMA observations in B7 at 0.1" resolution identified massive star clusters in the process of formation in the core of the NGC 253 starburst (Leroy et al. 2018). The characterization of these clusters is needed to understand the high-efficiency "starburst mode" of star formation, the life cycle of massive clusters, and the effects of massive-star feedback on star forming clouds. This proposal aims to: 1) directly measure the ionizing photon flux and synchrotron emission in these objects, which impact the stellar masses and ages of the clusters, and 2) constrain the dust optical depth and dramatically improve estimates for the temperature and gas mass of these sources. Our observations also yield a direct constraint on the hardness of the ionizing radiation field, and through it on the high mass end of the stellar IMF in these young clusters. In combination with ALMA data in hand, we will also study the excitation of the molecular gas in the starburst at 2 pc resolution, and the impact of massive stellar nucleosynthesis in the cluster-forming gas. These data are key to build a picture of the dominant star formation mechanism in starbursting systems at low and high redshift. | Starbursts, star formation | Active galaxies | 2022-07-09T17:47:21.000 |
| 336 | 2017.1.01638.S | 94 | Accretion-flow survey in nearby radio galaxies | We propose a molecular absorption line (CO, HCN, HCO+, CS, and SiO) survey in four nearby radio galaxies to quest circumnuclear disk (CND) and accretion stream inside the 100-pc vicinity of non-starburst AGNs. Our ALMA Cycle-2 observations toward the radio galaxy NGC 1052 revealed a ring-like rotating CND in CO emission and rich absorption lines of CO, HCN, HCO+, CS, SO, CN, and SiO towards the nucleus. Appearance of vib-excited HCN and HCO+ indicates that the molecular gas is heated by warm dust radiation. We also detected extremely redshifted SiO absorption features (500 - 1700 km/s w.r.t. the systemic velocity). The SiO can be sputtered from dust particles which is losing angular momentum via radiation drag. In this proposal, we aim to investigate how common are molecular absorption features in CND of radio galaxies, and then estimate column density, excitation temperature, and accretion rate. Thanks to bright continuum background radiation, absorption study toward radio galaxies brings better detectability of molecules than emission lines and enables isotopologues and vib-excited spectral analyses. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2019-10-05T13:55:51.000 |
| 337 | 2015.1.00690.S | 36 | Validating Disk-based Dynamical Masses with Young Binaries | A more robust knowledge of young star masses would be incredibly valuable in many aspects of star and planet formation. In principle, we can derive precise (uncertainties of ~a few %) dynamical masses from the rotation curves of molecular gas disks that orbit young stars. But in practice, that disk-based technique relies on a complex modeling process: its absolute accuracy is not clear. There is a straightforward way of validating this technique, which relies on observing the few systems where two independent dynamical mass estimates are available - spectroscopic binaries with circumbinary disks. By comparing constraints from ALMA observations of CO gas in these disks with those from radial velocity variations from the stars, we can validate the disk-based method for estimating stellar masses. Ultimately, the results of this approach could then be applied to any isolated (single) young star with confidence, vastly increasing the database of dynamical stellar masses. To that end, we propose to observe the 12CO/13CO/C18O J=2-1 lines from the three disks known to orbit young spectroscopic binaries (GW Ori, UZ Tau E, and DQ Tau) that do not yet have firm dynamical mass measurements. | Disks around low-mass stars | Disks and planet formation | 2018-04-11T21:52:57.000 |
| 338 | 2015.1.00357.S | 276 | Kinematics of Massive Star Cluster in Formation | We propose to study the kinematics of gas in a massive protocluster, G286.21+0.17, that is the target of an ongoing HST study of proper motion kinematics of young stellar objects. The unique comparisons that will be possible between ALMA-derived gas kinematics and HST-derived young stellar object (YSO) kinematics will help answer fundamental questions associated with massive star cluster formation, such as: "What is the nature of spatial and kinematic substructure in gas and YSOs and how do they compare?" "What is the level of turbulent velocity dispersion of gas in comparison to stellar motions, and the implications for global support of the protocluster and thus the timescale of star cluster formation?". The ALMA observations will identify populations of dense cores in different tracers, which can be compared in terms of their spatial, kinematic and core mass function properties, to similar approved Cycle 2 observations of cores in a massive IRDC, thus probing different evolutionary stages of the massive star cluster formation process. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-10-07T00:00:00.000 |
| 339 | 2011.0.00208.S | 0 | Feeding and feedback in two nearby Seyfert galaxies | We propose to map the morphology and kinematics of the cold dense gas in two nearby Seyfert nuclei at the unprecedented spatial resolution of 0.45"=22-24 pc. Up to now, our NUGA study of molecular gas in AGN circumnuclear regions has shown that embedded, kinematically decoupled bars are able to feed the nuclei; however, we have been hampered by insufficient spatial resolution and sensitivity to trace the gas inside a 100 pc radius. In two Seyfert galaxies known to have embedded bars, NGC 1433 and NGC 1566 (at distances of 10 and 11 Mpc), ALMA will enable us for the first time to examine the ultimate contenders of nuclear gas fueling, (nuclear bars, dynamical friction, and/or turbulent viscosity). We will also be able to probe feedback processes driven by the AGN (entrained molecular outflows, P-cygni profiles in CO(3-2), HCO+(4-3)). We will improve our resolution by a factor ~5 (going to higher frequency and more nearby objects), and sensitivity by a factor 2, with respect to our previous results on NUGA. Finally, our complete ancillary multiwavelength data set, including high-resolution HST images, will enable us to examine with unparalleled detail outflows in ionized gas, dust emission in the mid- and far-infrared, and dust obscuration around AGN. In total we ask for 5hours observing time, including calibrations. | Galactic centres/nuclei, Outflows, jets, feedback | Active galaxies | 2013-10-02T12:43:18.000 |
| 340 | 2017.1.01640.S | 69 | Probing Subsurface Water Ice Reservoirs on Ceres: From Winter to Summer | We propose to continue our NASA-funded Ceres thermal mapping campaign in ALMA Cycle 5 by observing Ceres with both C43-9 and ACA in Band 6 for 9 hours each. Our objectives are to: 1) Complete the seasonal thermal profile of Ceres surface with observations near perihelion; 2) Correlate ALMA thermal maps to major geological features; and 3) Search for HCN around Ceres. Abundant evidence suggests that shallow subsurface ice is present on Ceres, and thermal mapping has been proven as a powerful remote sensing tool to detect buried water ice. Measuring the seasonal thermal wave allows us to probe to an estimated depth of 0.5-1 m for Ceres where water ice has been suggested by Dawn mission, and is thus essential for our campaign. The proposed Cycle 5 observations will be near the perihelion when the surface temperature reaches the seasonal highest, and therefore contribute a critical point in probing the seasonal thermal wave. With C43-9, the proposed observations will provide 2x higher spatial resolution than our previous observations, allowing us for the first time to interpret the thermal units on Ceres in the context of geological features mapped by Dawn spacecraft. | Solar system - Planetary surfaces, Solar system - Asteroids | Solar system | 2018-11-08T15:47:50.000 |
| 341 | 2019.1.00702.S | 58 | The life of post-starburst galaxies at z~0.7: constraining the quenching mechanisms from stars and gas | In the last years, ALMA has started to probe the gas content in massive galaxies with low star-formation rates beyond the local universe. While the statistics are building up, the next step will be understanding the physical reasons that set the gas content in these galaxies. We propose to observed 6 massive post-starburst galaxies at z~0.7. The star-formation activities in these galaxies just shut down in the recent past, providing the best proxies to access the phsyical condition when the transition happened. All our targets have ultra-deep spectra, multi-wavelength photometry, and HST images for deriving accurate star-formation histories, stellar kinematics, morphologies, and star-formation rates. This is a rare sample for the joint study of stars, gas, and star-formation activities. We will derive the time evolution of gas content, the correlation between morphology and gas mass, and the relation between the stellar and gas kinematics during the key phase of galaxy evolution. These results will put stringent constraints on mechanisms that shut off the star-formation beyond the local universe. | Galaxy structure & evolution | Galaxy evolution | 2021-04-22T15:54:40.000 |
| 342 | 2023.1.00652.S | 0 | Unveiling the Mpc-scale structure of a maturing protocluster at z=3.61 | We propose ALMA CO(4-3) and [CI](1-0) observations in a protocluster field at z=3.61. This protocluster hosts a compact core that has a significantly high density of galaxies and a massive member in quenching, suggesting the structure is in maturing phase. Recently, five galaxies in this structure have been spectroscopically confirmed at z=3.5-3.61 by NOEMA CO(4-3) detections, unveiling its protocluster nature. Remarkably, a Mpc-scale structure was found around the protocluster core, as evidenced by an overdensity of submillimeter galaxies and ~100 candidate members with consistent photo-z. These strongly suggest this is a Mpc-scale protocluster at z=3.61 with a likely collapsed core. With the proposed observations we will (1) unambiguously reveal the large-scale structure by targeting 10 SMGs in a 3x3 Mpc^2 area, (2) derive molecular gas mass and SFEs via [CI](1-0) and identify if the most massive member is in quenching. The observations will also resolve the compact core, and allow us to (3) assess the dynamical state of the protocluster core by measuring the phase-space distribution and velocity dispersion. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2025-11-14T10:33:06.000 |
| 343 | 2022.1.00510.S | 400 | The COCOA survey: CO in Coma with the ACA | We propose to observe CO(2-1) in 142 galaxies in the Coma cluster, selected to have ongoing star formation according to 12 micron observations. The sample is representative, goes out to ~R200 (the radius at which the density is equal to the critical density of the local Universe, multiplied by 200) and spans a wide range of both stellar masses and star formation rates. The Coma cluster is by far the most massive cluster in the local universe. We aim to study the effects of such an extreme environment on the molecular gas, the direct fuel for star formation. Moreover, we aim to compare the molecular gas in Coma galaxies to that in Fornax and Virgo galaxies, and to identify the quenching mechanisms that dominate in different mass galaxy clusters. Ample ancillary data is available, such as Ha, 12 micron, FIR, and HI, allowing us to study scaling relations and ISM phase ratios, and compare these to other clusters as well as the field. Additionally, the Coma cluster is known to harbour several cases of extreme ram pressure stripping, allowing us to study the state of the molecular gas in such objects. | Galaxy groups and clusters | Cosmology | 2024-07-12T07:35:47.000 |
| 344 | 2013.1.00092.S | 27 | How do massive star forming galaxies at the peak of cosmic star formation shut down? | Throughout cosmic time, the bulk of field star-forming galaxies (SFGs), which form a fairly tight sequence in stellar mass versus star formation rate (hereafter, "main-sequence"),grow by gas accretion/minor mergers and in-situ star formation until their stellar mass exceeds the Schechter mass, logMS*~11, at which point they rapidly shut down and join the red sequence. Why is this so? We propose to measure CO-based molecular gas fractions and gas depletion time scales of a statistically significant sample of massive (M*≥MS) z~2 SFGs that are below the main sequence and thus should be in the process of transitioning to the red sequence. The proposed observations, along with our other data of SFGs at z~1-2 above and on the main sequence, will test for two main proposed INTERNAL quenching mechanisms. Rapidly dropping gas fractions below the main sequence would favor AGN feedback driving the shutdown. Rapidly increasing depletion time scales would favor morphological quenching, where the buildup of a massive bulge/spheroidal component acts to stabilize the galaxies against global gravitational instabilities,as a key player. | Galaxy structure & evolution | Galaxy evolution | 2015-08-28T23:55:17.000 |
| 345 | 2021.1.01356.S | 5 | Eccentric gas motion in the protoplanetary disk around MWC 758 | A massive planet in a protoplanetary disk could excite the disk to be eccentric, and the gas motion and dust distribution could have different amplitudes and phases of the eccentricity, depending on the dust-gas coupling and planet orbital eccentricity. ALMA continuum observations have revealed an eccentric dust ring in the protoplanetary disk around MWC 758, while the eccentricity of the gas motion in the MWC 758 disk has not yet been constrained. We have analyzed the ALMA archival 13CO data of MWC 758 and obtained a tentative detection of the gas eccentricity at a 2sigma level at the radius of the dust ring. Therefore, we propose to observe MWC 758 in CO isotopologue lines at high angular (0.1") and velocity (0.05 km/s) resolutions to measure the possible gas eccentricity. With our proposed observations, we expect to detect any gas eccentricity larger than 0.03 (if present) in the MWC 758 disk. Through the comparison of the amplitudes and phases of the gas and dust eccentricity, we will be able to constrain the gas-dust coupling (or the Stokes number) and planet orbital eccentricity in the MWC 758 disk. | Disks around low-mass stars | Disks and planet formation | 2022-12-02T08:08:09.000 |
| 346 | 2023.1.00588.S | 0 | Filling in the missing piece of the water trail: D2O observations in a protoplanetary disk | Water is a crucial ingredient for life as we know it on Earth. Furthermore, water enhances planet formation and it is the main carrier of oxygen, one of the most abundant elements. Still, the trail of water from clouds to planets is unclear. Water on Earth may be inherited from its parent molecular cloud, but it is also possible that water has been destroyed and reformed along the water trail from the cloud to the disk. Recently, observations of the HDO/H2O ratio in a young disk around an outbursting star have shown that water likely is inherited from the parent cloud. However, models have shown that the reprocessing of water in protostellar envelopes and disks can lead to a similar HDO/H2O ratio to that in the case of inheritance. Thus, we propose to use the most sensitive tool to distinguish these scenarios: D2O/HDO to HDO/H2O ratio. We target D2O in the same disk where HDO and H218O already have been detected at high signal to noise, filling the gap in D2O observations in a key stage evolution from clouds to planets. Therefore, we will observe D2O to observationally the complete water trail, especially the crucial step from cloud to disk. | Disks around low-mass stars | Disks and planet formation | 2025-08-05T11:51:25.000 |
| 347 | 2022.1.01655.S | 5 | Resolving the base of the jet associated with an O-type protostar | Protostellar jets/outflows are essential elements of the star formation process and provide significant clues about the underlying star formation. How they are launched and collimated is still under debate and the details of interactions between jets and outflows remain unclear. The origin of jets from more massive protostars has been investigated even less. High angular resolution observations reaching the base of the jet can provide the most relevant information to deduce its launching and collimating processes. The O-type protostar in G026+0.05 shows scaled-up versions of basically all the features found in the low-mass star formation regions. In this proposal, we request to obtain the first highest resolution ALMA data of the base of its collimated S-shape precessional jet. By combining previous ALMA and VLBA water maser proper motion results, the proposed observations will allow us to constrain the jet launching, collimating, and wind components in this unique target and will also enable us to compare the jet/outflow properties between low- and high-mass protostars and test the validity of the X- or disk-wind models in the regime of O-type protostars. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2024-08-22T06:10:01.000 |
| 348 | 2022.1.00224.S | 863 | The Home Straight - Completing the CO Redshifts of Herschel's Brightest SMGs | These observations are the final step towards finishing the redshift catalogue of 207 bright, high-redshift Herschel sources (S500 > 80 mJy, z_phot > 2). Extensive redshift searches have already robustly identified 77% of the redshifts, and using all knowledge up until now, we propose efficient ACA observations to find the redshifts for the remaining 48 galaxies using Bands 3, 4, and 5. Sample completion will enable efficient and unbiased spectroscopic follow-up across all sources, and provide a complete picture of cosmic star-formation seen by Herschel at the peak of cosmic evolution. These final observations of 48 galaxies require 124 hours, and fall in three separate categories: 1) we efficiently target lines to resolve redshift-degeneracies; 2) we observe fainter galaxies with deeper integrations; and 3) we cover the redshift desert for sources with deep integrations that did not reveal any line signatures. This project marks the completion of our study of the most intensely star-forming environments detected by Herschel, and will help trace rare populations (HyLIRGs, protoclusters, ...), enable a high-quality composite spectrum and will even allow for cosmological tests. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-02-01T06:28:24.000 |
| 349 | 2015.1.01112.S | 34 | Polarization and Protostars: Probing Magnetic Fields Across Disks | We propose a polarization survey of 32 embedded protostars in the Ophiuchus molecular cloud. We will observe our sources at resolutions of ~40-500 AU, which will sample well the polarization across their disks down to a sensitivity of 38 uJy per synthesized beam. Only a handful of protostellar disks have been observed in polarization at < 100 AU scales to date. This study is the first to survey magnetic fields in a comprehensive, homogenous sample of protostellar disks. With these data, we will identify the dominant magnetic field morphology (e.g., toroidal or poloidal) associated with the disks and compare these morphologies to the disk properties, testing our observations against theories. Moreover, our observations will also recover emission associated with the inner envelope. Thus, we will also compare and contrast the disk field morphologies with the envelope morphology. These observations will connect magnetic field morphologies in disks with star formation processes for the first time. | Low-mass star formation | ISM and star formation | 2018-11-03T04:31:47.000 |
| 350 | 2022.1.01324.S | 27 | The kpc-scale Dust Temperature, Star Formation and ISM at z=7.3 | REBELS-25 - the brightest known star-forming galaxy in the epoch of reionization - provides a truly unique laboratory of the early build-up of massive galaxies. Recent Cycle 8 ALMA observations have carefully mapped the spatially resolved dust continuum and [CII] emission in this z=7.306 starburst, revealing clumpy star formation, potential spiral structure and clear rotation in a galaxy only 700 Myr after the Big Bang. Through combined unresolved Band 4 and 9 observations and ~0.2" (~1 kpc) Band 8 observations, we aim to 1) simultaneously constrain the global dust temperature and emissivity in the galaxy; 2) construct spatially resolved maps of the dust temperature, infrared luminosity and obscured star formation, and; 3) utilize the [OIII] 88um line to reveal its resolved multi-phase ISM. These timely observations will provide insight into an array of key topics in early galaxy evolution, such as the spatial distribution of (hot) dust, the origin and nature of the high-redshift Schmidt-Kennicutt relation and the physical processes governing the escape of the ionizing photons driving reionization. | Starburst galaxies | Active galaxies | 2023-12-29T02:15:47.000 |
| 351 | 2019.1.01075.S | 10 | Resolving the [CII] distribution and kinematics of "normal" galaxies at the end of cosmic reionization (resubmission) | Substantial advances have been made in the recent years to understand the nature of the bulk population of galaxies at the end of the cosmic reionization era, at z=5-8, based on detection of the [CII] line emission. We are now in an excellent position to give one step further by resolving this emission, and understand the governing physical processes to form these galaxies. Here, we propose to complete our high resolution [CII] line observations (0.5-1.5 kpc scale) of a sample of 5 galaxies at z=5.5-7.0, which represent the bulk galaxy population in this epoch. The brightest of our objects was not completed in Cy6, thus leaving out the source were we could do the most detailed analysis. We aim to spatially resolve the [CII] line emission (0.1-0.3") and perform dynamical modeling. We have two primary goals, (i) to measure the morphology and distribution of the cool gas, compared to the star-forming and stellar components (i.e. mergers, disks, clumpy) and (ii) to perform dynamical modelling of the velocity field. This will lead to estimation of key parameters, including gas and dynamical masses, depletion timescales, and gas fractions and their relation to UV radiation fields. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2022-05-04T00:18:01.000 |
| 352 | 2017.1.01033.S | 42 | First mapping of B-fields in the closest vicinity of a proto-brown dwarf candidates | Magnetic fields (B-fields) are believed to play key role in low mass star formation, allowing the cores to gradually condense out of a magnetically subcritical background cloud, through ambipolar diffusion thus guiding the collapse and producing flattened cores and disks. But the importance of B-fields in the formation of brown-dwarfs (some brown dwarf candidates are identified with outflows and disk like structure) has not been explored. We wish to test these models by using ALMA's potential for the first time to zoom in the magnetic fields in the densest part of the cores containing embedded proto-brown dwarf candidates. By mapping the B-fields at high angular resolution, we will be able to correlate the rotation axes of the core (i.e outflow direction) and B-field orientation. Molecular line observations of these cores using ALMA have been proposed by Lee et al. which will give the kinematical information of the cores. Using the kinematics and our proposed polarization observations, we will estimate the B-field strength from Chandrasekhar-Fermi relation which will allow us to understand the energy budget of the cores. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-06-15T09:31:57.000 |
| 353 | 2017.1.01363.S | 29 | Revealing the Shock-interacting Molecular Gas toward the Magellanic Superbubble 30 Doradus C | Supernovae (SNe) have a profound influence on the evolution of the interstellar medium, high-energy radiation, and efficient acceleration of relativistic particles via shock interaction with ambient interstellar gas. 30 Dor C is one of the unique remnants of multiple SNe the so-called superbubble of the Large Magellanic Cloud, which is known as a bright synchrotron X-ray and TeV gamma-ray emitter. Recently, we revealed molecular gas interacting with 30 Dor C by using Mopra and ASTE in the 12CO(J=1-0) and 12CO (J=3-2) emission lines. However, we could not reveal the detailed structures and physical conditions of the CO clumps because of the poor spatial resolution of 5-10 pc. Most recently, we have obtained 12CO(J=1-0) data by using ALMA and found 2-4 pc scale CO structures in the northwest of 30 Dor C. We here propose to observe the southwest of 30 Dor C where there is also an association with giant molecular clouds. We will resolve the giant molecular cloud into clumps and determine their physical properties by ALMA observation with 12CO(J=1-0,3-2) and 13CO(J=3-2) at the resolution of 0.8-1.0 pc. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-12-09T00:00:00.000 |
| 354 | 2024.1.01553.S | 0 | Deciphering cold molecular gas dynamics in powerful radio galaxies: a comprehensive ALMA+MUSE study | This proposal seeks to unveil the intricate dynamics of cold molecular gas in 27 powerful radio galaxies (RGs) in the nearby universe (z<0.3) from the 3CR MURALES sample. The proposed sample complements existing ALMA archival and VLT/MUSE observations, providing a crucial component to enhance our understanding of AGN fueling mechanisms. We aim to use CO(2-1) observations to probe the molecular gas reservoirs, essential for AGN activity and jet-mediated feedback in their host galaxies. By quantifying cold gas masses, morphologies, and kinematics, we will investigate the role of gas inflows in AGN fueling processes across different radio morphologies and excitation states. We will correlate these findings with ionized gas and radio properties to determine if cold gas accretion is predominantly a feature of high excitation RGs rather than low excitation RGs, and assess the prevalence of molecular outflows in these powerful RGs. ALMA's unique sensitivity will offer a new lens on their cold gas dynamics, bridging the gap between molecular and ionized gas phases. The insights gained will provide a comprehensive picture of AGN feeding and feedback, key processes to galaxy evolution. | Active Galactic Nuclei (AGN)/Quasars (QSO), Early-type galaxies | Active galaxies | 2025-11-20T13:55:58.000 |
| 355 | 2018.1.00935.S | 126 | Characterizing the earliest stages of protostellar core collapse | We propose to complete ALMA observations of two highly centrally concentrated cores on the cusp of forming a low mass protostar or first hydrostatic core. Despite lacking infrared protostellar detections, ALMA Cycles 0 and 2 observations reveal compact (< 1", or 140 au), extremely dense continuum condensations embedded within elongated structures toward both cores. The proposed continuum observations in Bands 3, 4, and 7 will reveal the core structure at matched 0.6" resolution (80 au) to determine the dust emissivity, masses, and density profiles via radiative transfer modeling. We will simultaneously perform a suite of molecular line observations at 1" (140 au) resolution to i) measure infall, rotation, and collapse motions; ii) determine the deuterium fractionation of N2H+ across the cores to constrain the luminosity of any undetected, embedded source; and iii) confirm the tentative lack of low-velocity outflows. These proposed observations will provide, for the first time at ~100 au scales, comprehensive physical, kinematic, and chemical pictures of two rare cores caught at the earliest stages of star formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-08-16T02:27:52.000 |
| 356 | 2017.1.01184.S | 17 | Calibrating Chemical Tracers of Primordial Gas in Circumstellar Disks | The lifetime of primordial gas in circumstellar disks is a fundamental quantity required for understanding planet formation processes. The uncertainties involved in relating conventional gas tracers, including dust and CO, to the total disk mass increase significantly as the disk evolves. We propose a novel approach using nitrogen-bearing species, specifically N2H+, to track primordial H2 gas. The low levels of available nitrogen incorporated into solid solar-system bodies relative to carbon suggest that nitrogen will remain present in the gas over longer timescales. Elevated N2H+/CO ratios of two Upper Sco disks observed in ALMA Cycle 3 (2015.1.01199.S) support this hypothesis. Here we propose further investigation of the N2/CO ratio at different stages of disk evolution through observations of N2H+ and HCO+ in three mature disks and one transitional disk in Upper Sco (5-11 Myr old) and one debris disk (30 Myr old) with previous CO detections by ALMA. This will provide crucial data regarding the primordial gas content of these evolved systems. Affirmative results would lead to a future survey of a large number of disks to constrain the dissipation timescale of primordial gas. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2019-10-03T20:15:38.000 |
| 357 | 2019.1.00572.S | 48 | The launching mechanism of outflows | Molecular outflows are the most prominent signatures of ongoing star formation. Yet, how and where they are launched has remained a matter of debate since their discovery. Our team published the first resolved images of outflow launching towards TMC1A, demonstrating that the launching extends out to 25 au in the disk. Since then, we have observed the very young Class 0 source B335 and we find that, instead, gas is launched only at small radii. Tracing the wind launching down to the smallest spatial scales is important not only for understanding outflows in general, but, because outflows transport mass and angular momentum from the system, it is also essential for understanding disk evolution and, subsequently, planet formation. We propose to observe the three main isotopologues of CO(2-1), plus SiO(5-4), a number of SO/SO2 lines and dust continuum towards 5 carefully selected targets (IRAS15398, Lupus 3 MMS, L1527, Oph IRS 3, and L1489). These data will be combined with our data towards TMC1A and B335, plus available archival data for other sources for the purpose of constraining the launching mechanism across different stages of early star formation. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2022-11-24T19:17:15.000 |
| 358 | 2017.1.00288.S | 4 | Initial conditions for disk and planet formation in B335 | Disks are the birthplaces of planets, and understanding how disks form naturally inform us of the initial conditions for planet formation. Disks form when a rotating cloud core collapses under its own gravity, and they are a natural consequence of angular momentum conservation. However, when exactly they form, particularly in the form of Keplerian disks, is still an open question. Our primary goal is to observe one of the youngest disks, the one surrounding the deeply embedded object B335, to directly constrain the size of this growing disk and to distinguish between a rotationally supported Keplerian disk and a pseudo-disk by observing this source at a resolution of 0.02" (2 au) in a combination of gas and dust tracers. Simultaneous to disk formation, protostellar winds are launched from the disk, as we have recently demonstrated, and they carry away angular momentum from the forming system. How the wind launching affects the disk build-up (and vice versa) is a secondary goal of this proposal. In this manner, ALMA provides a comprehensive view of the initial conditions for planet formation at the very earliest stages of disk formation. | Low-mass star formation | ISM and star formation | 2019-05-22T14:28:45.000 |
| 359 | 2023.1.01012.S | 0 | Does Molecular Gas Survive Quenching Near Cosmic Noon? | Theoretical predictions of galaxy quenching predict that the absence of molecular gas (via e.g., depletion, removal, or heating) should precede the cessation of star formation. However, recent ALMA observations of young quiescent galaxies below z~0.7 have revealed that galaxies retain significant gas reservoirs (>10^10 Msun) after they quench; older quiescent systems are gas poor. The depletion time of ~10 Gyr is much longer than the ~200 Myr timescale on which gas reservoirs seem to vanish, implying that gas is removed in some other way. However, these low-z galaxies may be odd exceptions that shut off long after the bulk of massive galaxies quench. The few observations of CO in quiescent galaxies at z>1 have failed to detect significant H2 reservoirs. This contrast may reflect a difference in physical conditions, as all higher-z targets have older stellar populations. In this proposal we leverage a novel spectroscopic dataset to search for CO(2-1) emission in five young (<200 Myr old) quiescent galaxies at z~1.1 to quantify their molecular gas contents. This study provides a crucial test of the interplay between quenching mechanisms and molecular gas reservoirs near cosmic noon. | Surveys of galaxies, Early-type galaxies | Galaxy evolution | 2025-01-10T14:34:38.000 |
| 360 | 2022.1.00592.S | 17 | Nature of the mm-continuum signal from PDS70c | How do dust grains trickle through protoplanetary gaps and reach the circumplanetary-disks (CPDs) that regulate the formation of giant planets? What sort of grains are such CPDs composed of? The recent detection, thanks to deep ALMA observations, of compact 350GHz signal around an Halpha point source, i.e. PDS70c, may bring some clues towards these questions. However, although the mm-dust continuum is usually associated to dust emission, free-free emission can be dominant in the case of a compact body, such as a star or planet. The main goal of this proposal is to test whether the bulk of the signal seen in PDS70c corresponds to free-free emission or to dust emission. In the case of pure dust emission, we also aim to estimate the size of the dust grains comprising the CPD using its spectral index. The Band4 continuum will test for a free-free component, while the Band9 continuum will measure the mass of optically thin emission from small dust. A middle point in Band8 will be used to test for a concave spectrum, resulting from both free-free and dust emissions, and will allow accounting for dust optical depth if the free-free contribution is found to be negligible. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2025-02-19T14:21:23.000 |
| 361 | 2013.1.00397.S | 2 | Molecular Gas in the Nearest, Extremely Low-Metallicity, Star Forming Galaxy, Leo P | Leo P is the most extremely low metallicity (Z = 0.03 Zsun), low-mass (M_HI = 1x10^6 Msun) star forming galaxies in the nearby universe (D = 1.72 Mpc). The proximity of Leo P affords us the best opportunity to constrain recent star formation models in such an extremely low-metallicity environment in comparison to much more distant objects such as I Zw 18 (D = 18.2 Mpc). We propose to observe the 115 GHz CO (J=1-0) emission in Leo P with a single-pointing observation requiring 5.51 hours (including overhead) of ALMA time. These observations will help to constrain recent star formation models at low metallicity which suggest molecular gas may not be required to form stars. Regardless of a detection or a non-detection, this observation will put valuable constraints on the CO luminosity and its relationship to other star formation tracers such as L_Halpha, L_B, stellar mass, and total HI mass as well as provide important insight into the low metallicity star formation process prevalent in the early universe. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-02-25T18:19:21.000 |
| 362 | 2018.A.00061.S | 350 | ACA Mapping of the Star-Forming Northern Tip of the Large Magellanic Cloud Molecular Ridge | The Molecular Ridge is the most salient molecular feature in the Large Magellanic Cloud. It is mostly quiescent except for its norther region, which experiences progressively younger and more embedded star formation activity away from the 30 Doradus nebula. We propose to map a 10'x26' area encompassing all massive star formation in the area using only the ACA. This will allow us to study the broader environment of the star forming clouds, characterize the progression of star formation activity using YSOs and statistical techniques, and create a large catalog of molecular clouds with which to study the effects of feedback in the area. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2021-06-09T00:00:00.000 |
| 363 | 2012.1.01029.S | 5 | 50-pc resolution mapping of a unique strongly lensed z=2.3 sub-mm galaxy | We propose Band 9 and Band 7 observations in compact and extended configurations of the strongly gravitationally lensed z=2.32 star-forming galaxy SMMJ2135 (The "Cosmic Eyelash"). The magnification of this galaxy by a foreground cluster, combined with the high resolution of extended configuration ALMA observations will allow us to probe to high resolution (0.08") corresponding to ~50pc in the source plane of the galaxy. This will provide a factor of ~3x higher resolution than our previously obtained sub-mm maps. This physical scale is comparable to the charcteristic size of local GMCs. Complementary observations in the compact array will ensure that we recover all the flux and probe a large range of angular scales within the source. We will combine our rest-frame 140um and 260um observations with existing comparable resolution maps of CO(1-0), CO(6-5) and radio emission to measure the sub-mm morphology, the internal dust temperature structure, the star-formation efficiencies in GMCs and the spatially-resolved far-infrared - radio correlation within a high-redshift star-forming galaxy. Our science goals are: -To measure the sub-mm morphology of SMMJ2135 on 50-pc scales, determining the number, size, spatial distribution and rest-frame 140um luminosity of the star-forming regions on these scales. -Combine the 450um and 870um photometry for the star-forming regions to measure the luminosity and hence star formation rate for each clump. -Combine the star-formation rates of the clumps with estimates of their gas masses to test whether their star formation efficiencies are significantly higher than GMCs in the Milky Way. Furthermore, we will investigate the Kennicutt-Schmidt relation on 50-pc to ~kpc scales. -We will measure the spatially resolved far-infrared radio correlation. Although these results will be based on a single galaxy, SMMJ2135 is representative of the high-redshift, gas-rich, star-forming population. Moreover, these observations will provide a test of whether the scaling laws between gas and star formation developed at z=0 are applicable in the gas-rich, rapidly evolving ISM in high redshift galaxies. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-08-07T11:05:20.000 |
| 364 | 2012.1.00759.S | 0 | The formation of giant molecular associations at colliding region by an interaction of galaxies | We propose 12CO(J=1-0) and 12CO(3-2) observations of interacting galaxies in early stage NGC 4567/68 with ALMA. Galaxy interactions are of great importance on evolution of galaxies. Although one of most important features of interacting galaxies is an enhancement of star formation activity, the mechanism to activate star formation in interacting galaxies is still unknown. Since stars are made from molecular gas, it is crucial to know how molecular gas is affected by the interaction for understanding active star formation in interacting galaxies. Our aim is to investigate the formation mechanism of large and massive giant molecular associations (GMAs) which are suggested by recent observations and simulations and are precursors of starbursts. The target should be selected from interacting galaxies in ``early stage'' to understand the formation of GMAs in interacting galaxies because starbursts which consume such GMAs have already occurred in more advanced stage. NGC 4567/68 galaxy pair is one of most suitable pairs to achieve our purpose. This pair is interacting galaxies in the early stage of the interaction. Previous observational studies such as HI, CO and H alpha indicate the effective GMA formation in their overlapping region. Their distance of 16 Mpc is preferable to resolve GMAs with ALMA cycle 1. We observe total molecular gas tracer 12CO(J=1-0) and dense (10^4 cm^-3) gas tracer 12CO(J=3-2). CO(1-0) observations enable us to identify each GMAs and to derive the size, mass and formation rate of GMAs (mass fraction of GMAs in total gas mass), virial mass and star formation efficiency. CO(3-2) observations can reveal where dense gas is formed and a ratio of CO(3-2) to CO(1-0) shows the site of prospective star formation. Velocity information is useful to investigate the formation mechanism of GMAs. These are necessary to understand what the key to future active star formation is and physical processes of evolution of GMAs. CO(1-0) will be observed with 1 rectangular field of 135’’ x 175’’ to cover whole system. Observing region of CO(3-2) consists of 3 rectangular fields (discs of NGC 4567 and NGC 4568 and the overlapping region). To resolve GMAs, we need a spatial resolution of 2" (155 pc) and a velocity resolution of 5 km/s. We intend to detect GMAs whose mass of 1 x 10^6 Msun with 5 sigma reliability. Assuming a smallest CO(3-2) over CO(1-0) ratio of 0.2, estimated time for CO(1-0) is 3.01 hours and CO(3-2) is 3.51 hours including the ACA and TP and calibration. These observations cannot be performed without ALMA. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2015-07-18T12:19:05.000 |
| 365 | 2016.1.00261.S | 55 | Radio jet-gas interaction and star formation: Excitation and dense molecular gas | NGC 5128 (Centaurus A) is the most nearby powerful AGN, widely studied at all wavelengths. Molecular gas is found at a distance of ~15 kpc from the galaxy centre, associated to HI shells, via CO emission line detections that we recently revisited with APEX and ALMA. The molecular gas lies inside some FIR and UV bright star-forming filaments that are observed in the direction of the radio jet. The molecular depletion time in these regions that recently formed young stars is however very long (7 Gyr). We propose here to use ALMA to study the radio jet-gas interaction in the filaments via dense gas tracers. (i) We propose to map the CO(3-2) along the filaments with a resolution of 1.1"~18 pc in order to identify local variations of the gas excitation along the filaments and look for associations with the jet position or the FUV star forming clumps. (ii) We propose to observe the HCN and HCO+(1-0) into the unexpected brightest CO position found with APEX (at 1.5"~25 pc). Together with our cycle 3 CO(1-0) data, ALMA can now probe for the very first time the physical conditions (n,T) of the inefficient star forming reservoir of molecular gas in Cen A filaments. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-10-25T00:03:39.000 |
| 366 | 2013.1.00988.S | 35 | Understanding AGN feedback with gas chemistry in NGC 1266 | NGC1266 is an early-type galaxy in the southern sky that has recently been shown to be expelling its molecular gas through a large AGN-driven molecular outflow. In this proposal we aim to investigate the physical and chemical properties of the ISM in the central few hundred parsecs of this extraordinary galaxy. We propose to conduct an unbiased line-survey of the 3mm band, using chemical tracers in the ISM to investigate the mechanism driving the molecular gas from this galaxy, and thus more generally constrain how star-formation can be quenched by AGN feedback as galaxies move onto the red sequence. Our data will be the deepest and highest velocity resolution line survey ever conducted in an early-type galaxy, enabling us to explore in depth the astrochemistry in high-metallicity and alpha-element enhanced environments, as well as sheding light on the mechanisms responsible for AGN feedback. | Outflows, jets, feedback, Galaxy chemistry | Active galaxies | 2016-08-29T12:53:54.000 |
| 367 | 2023.1.00064.S | 0 | Submillimeter He+ and H recombination lines as a novel diagnostic tool of obscured energy sources | To identify energy sources of galaxies at sub/mm (least affected by dust extinction) can be an excellent way to uncover dust-obscured AGNs, which are elusive at optical. Although some molecular and atomic diagnostic line ratios have been proposed, their interpretations are not straightforward as the ratios depend on many factors (abundance, excitation, opacity). Here we propose to use He+-to-H recombination line (RL) ratio (He+51a and H32a in this work) as a simple and novel discriminator of AGN and starburst. These lines probe the energetic ionized regions around a heating source. Based on a firm physics, we argue that the He+-to-H line ratio simply reflects the "hardness" of the incident UV radiation field, which is critically different between AGNs and starbursts. We propose to test this diagnostic method in the nearby well-defined AGN, the Circinus galaxy. As the energetics of its circumnuclear region is dominated by the AGN, we can measure the line ratio characteristic to the AGN environment. The results will be compared with ratios in starburst systems (values will be available from other existing programs) to see if there is really a distinct difference in this line ratio. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-12-20T06:25:45.000 |
| 368 | 2018.1.00810.S | 92 | A new pathway to the formation of oxygenated amines in protoplanetary disks | Although often overlooked as a fundamental driver of nitrogen chemistry, nitric oxide (NO) is a highly reactive species leading to the formation of oxygenated amines, amides and ultimately amino acids. While NO is routinely observed in the interstellar medium, this species has not been found in protoplanetary disks (or comets). We therefore propose here to search for NO and two of its daughter molecules, nitrous oxide N2O and hydroxylamine NH2OH, in the protoplanetary disk surrounding the young Solar system analog TW Hya. The observations analyzed with a suite of elaborate disk physical-chemical models, will allow us to derive reliable abundance ratios (or to provide the most stringent upper limits in the ratios). This is an unavoidable step in characterizing the synthesis of prebiotic molecules (oxygenated amines and amides) in planet-forming environments. In addition, the proposed study will guide further development of very extended and hence uncertain N-chemical networks both in the gas phase and via grain-surface reactions. | Disks around low-mass stars | Disks and planet formation | 2020-07-26T10:31:57.000 |
| 369 | 2016.1.00768.S | 35 | Luminous, Dust-Enshrouded High-z Galaxies Selected by Gamma-Ray Bursts | Recent observations have demonstrated that a substantial fraction of GRBs originate from heavily dust-obscured and luminous galaxies at z>1, a population that until recently was not thought to produce GRBs in significant numbers. This discovery has important implications for the connection between GRBs and the overall star-formation rate, suggesting that GRBs can occur in massive and dusty galaxies under certain conditions. We propose to obtain ALMA continuum observations of the ULIRG hosts of six GRBs at z~2 to directly measure their obscured star formation rates, resolve the structure of the hosts in dust emission, and determine whether the bursts originate from compact super-starbursts or more classical modes of star formation. These observations will fill a critical gap in our knowledge of the GRB population, identifying the physical conditions necessary to form GRBs in the high-redshift universe and providing new insight on the nature of the GRB progenitor and its ability to probe conditions in the most dust-enshrouded galaxies. | Sub-mm Galaxies (SMG), Gamma Ray Bursts (GRB) | Galaxy evolution | 2017-12-12T17:50:43.000 |
| 370 | 2023.1.01066.S | 0 | Growing Brighest Cluster Galaxies: a statistical study of the molecular fuel at early times | We are undertaking a multi-faceted study of the in-situ stellar mass growth of Brightest Cluster Galaxies (BCGs) through cosmic time. These systems are the most massive galaxies at any epoch and form at the dense centres of galaxy clusters. Once thought to be outliers they are now recognized as sensitive probes of hierarchical structure formation proceses such as gas cooling, galaxy merging and energy feedback mechanisms. Coupling Spitzer-MIPS observations of the Spitzer Adapatation of the Red Sequence Cluster Survey (SpARCS) to the OzDES spectroscopic survey has produced the largest spectroscopic sample of BCGs beyond z > 0.3 to date. Here we propose to undertake the first statistical and systematic study of the molecular gas content of a large number (63 total, 33 in this proposal) of spectroscopically confirmed BCGs. We aim to control, for the first time, for the degenerate properties of star formation efficency and redshift. This unique study will elucidate the in-situ mass growth of BCGs and provide constraints for models which currently struggle to reproduce the star forming properties of BCGs at early times. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2025-03-30T15:07:29.000 |
| 371 | 2019.1.00760.T | 30 | Characterization of Short GRB Afterglows | We aim to identify the first mm/submm afterglow associated with short GRBs for characterizing of the explosion physics of short GRBs based on our experiences on long-GRBs follow-up using SMA and ALMA. As we already demonstrated with ALMA and SMA, afterglow follow-up in mm/submm band is crucial to characterize synchrotron radiation and to derive explosion parameters. With our initial studies with SMA and ALMA, we focus on nearby (z~0.3) short GRBs that forward shock radiation could be detected with ALMA. The short GRB science is timely, because it shares the common compact object merger model with the gravitational wave transient. Since off-axis viewing of short GRB jet can basically explain the low-luminosity of associated short GRB of the gravitational wave transient caused by NS-NS merger, characterization of explosion parameters of short GRB as on-axis of the same jet could be the fundamental template for understanding the overall explosion. | Gamma Ray Bursts (GRB) | Cosmology | 2022-09-22T00:00:00.000 |
| 372 | 2011.0.00277.S | 0 | The mystery of water vapor in IRC+10216 | One of the highlights of the first year of Herschel's science program was the discovery of water vapor in the warm inner envelope of the carbon-rich Asymptotic Giant Branch (AGB) star IRC+10216 (CW Leonis). The water abundance derived from Herschel observations of carbon-rich AGB stars are typically 3 to 4 orders of magnitude larger than the photospheric abundance expected under thermochemical equilibrium. This huge discrepancy had led to the suggestions of several possible origins for the water vapor. The relative strengths of the high-excitation water lines in the Herschel data indicates the presence of warm water vapor close to the star. Only two, still competing, theories are consistent with the existence of warm water vapor: (1) the photochemistry model within a clumpy outflow (Decin et al. 2010, Nature), and (2) non-equilibrium chemistry associated with pulsationally-driven shock waves (Cherchneff 2011, A&A). However, Herschel lacks the spatial resolution needed to probe the very innermost regions of the outflow where the two competing models predict different spatial profiles. Currently, only ALMA provides the astronomical community with high enough a sensitivity and spatial resolution to discriminate between the two alternative explanations. We propose to observe vibrationally-excited water in the nu2=1 1_10 - 1_01 transition at 658 GHz. Making the first image of water in the envelope of a carbon-rich giant will stunningly visualize the capabilities of ALMA and will show the impact of ALMA on our understanding of the physics and chemistry going on in evolved stars. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2014-02-11T12:14:00.000 |
| 373 | 2019.1.01509.S | 16 | The cold gas content of the giant Sunburst Arc and low-mass substructures in the lensing cluster PSZ1 G311.65-18.48 | We propose ALMA observations of the strongly magnified giant Sunburst arc at z=2.37, gravitationally lensed by the Planck cluster PSZ1G311.65-18.48. We will detect the CO(3-2) transition at rest-frame frequency 345.8 GHz, which will allow us to trace the molecular gas content of the system. The system presents various compact star-forming knots, one of which appears as multi-imaged in the HST F814W band. Its MUSE spectrum shows narrow nebular high-ionisation metal lines indicating the presence of young massive stars, its estimated mass and size are typical of a young, massive stellar cluster, and it is a Lyman continuum emitter. We suggest that ~3.45 hr of ALMA band 3 observations with 0.1" FWHM resolution will be enough to detect the CO transition and to trace the morphology of the cold gas distribution in the arc, assess the impact of stellar feedback and, through continuum detection, appreciate the gravitational effects of small-scale substructures of 10^8 Msun on the potential of the lensing cluster. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2022-04-20T21:28:33.000 |
| 374 | 2015.1.00865.S | 13 | First zoom on an extremely young brown dwarf | The formation of brown dwarfs (BDs) is a hot field of research because there are no clear-cut examples of deeply embedded BDs (or proto-BDs), yielding the question of whether they form as a scaled-down version of low-mass stars or through a more violent process such as ejection from fragmented disks or cores. Recently, Submillimeter Array observations revealed the existence of an object, IC348-SMM2E, whose properties are extremely similar to those of Class 0 young stellar objects, but whose mass will most likely remain substellar even after completing the accretion process. The object is driving a compact outflow and is associated with a rotating structure perpendicular to the outflow, but the outflow, the dust continuum, and the disk structure could not be properly resolved, in part due to a lack of sensitivity. We propose to perform ALMA observations towards IC348-SMM2E, with an angular resolution of 0.1'', which will allow us to study for the first time with unprecedented detail the dusty disk, its kinematics, as well as the outflow of a Class 0 proto-BD. This will provide crucial clues to disentangle the different formation scenarios of BDs. | Low-mass star formation | ISM and star formation | 2018-01-13T05:18:35.000 |
| 375 | 2019.1.00613.S | 10 | Dissecting molecular tori of Seyfert galaxies | The long-sought images obtained by ALMA of the 'many faces' of the >10pc-size molecular torus in the Seyfert 2 galaxy NGC1068 have revolutionized the canonical pc-scale torus paradigm of unified AGN theories. The NGC1068 torus is lopsided and shows a surprisingly complex kinematics. This proposal aims at imaging with unprecedented resolution the 10-to-40 pc size molecular tori recently identified in 7 nearby Seyferts, which are part of our ongoing ALMA survey (GATOS). We propose to map the CO(3-2) and the HCO+(4-3) lines and their underlying continuum emission in the circumnuclear disks (CND) of the 7 GATOS targets for which we already have images obtained at 0.1"(7-13pc) using now a spatial resolution of 0.02-0.03"(2-3pc). This project will expand by an order of magnitude the number of AGNs observed with a spatial resolution and sensitivity similar to those achieved in NGC1068. These observations will allow to build 3D morpho-kinematic models of the torus, disentangling Keplerian rotation from inflow and outflow motions, derive BH mass estimates, and map the torus-CND connections to establish the current feeding budget in a representative sample of nearby AGNs. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-10-14T19:18:17.000 |
| 376 | 2022.1.00963.S | 10 | Multi-band spectroscopic study of V1309 Sco | Red novae are known products of stellar mergers between non-compact stellar objects. Such interactions are an extreme form of binary interaction, and as such are an opportunity to examine the physics behind such catastrophic events, including the common envelope phase. Previous sub-mm observations with ALMA have revealed an abundance of molecular emission within the circumstellar environments of red nova remnants that traces gas ejected from the binary components during the merger event. We propose to use ALMA in bands 3, 6 and 7 to examine multiple molecular species in detail (e.g. SO2, CO, SO, SiO, HCO+, AlO) and analyse the specific physical properties of different molecular species in the circumstellar environment of the remnant. This will increase our understanding of the remnant's structure, including the properties of different gas components and the possibility of components of neutral and ionised molecular gas. The measurements of multiple transitions of each molecular species will aid us in constraining these physical properties and overall will help us understand the chemical and dynamical evolution of V1309 Sco, and of stellar mergers in general. | Evolved stars - Chemistry, Transients | Stars and stellar evolution | 2024-07-04T17:58:40.000 |
| 377 | 2021.1.00879.S | 16 | Detecting the Circumplanetary Disk around the Elias 24 Planet | To understand what impacts the diverse exoplanet population that is currently observed, we must study young planets in their nascent environment: protoplanetary disks. In the young Elias 24 disk, where ALMA images revealed a deep gap, direct imaging at 3.8microns detected a point-source exactly inside. Hydrodynamical simulations explain the observed gap by planet-disk interactions, while the point-source luminosity is compatible with a 0.5-5MJup planet, depending on the presence or lack of a circumplanetary disk (CPD). Here we propose to observe 0.84mm continuum emission - at exquisite sensitivity - from the Elias 24 system: to uncover CPD emission from inside the gap and study the possibly youngest protoplanet to date. Important constraints on CPD mass can be obtained with ALMA, e.g., quantifying the available material to form planetary satellites, and our ALMA simulations demonstrate that we will obtain 5 times better sensitivity to CPD emission than existing observations from DSHARP. To achieve the best contrast for CPD emission in the gap, we will characterize and remove the circumstellar disk emission, while performing the analysis in the uv-plane to avoid imaging artifacts. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2023-09-02T19:04:43.000 |
| 378 | 2022.A.00034.S | 6 | B3 observation of a super-deep field in HDF-S | The HDF-S field has many orbits of HST data as well as optical/NIR followup, but almost no coverage from ALMA. Observing a blank field inside HDF-S that goes deeper than any existing sub-mm observations in the more subscribed fields could motivate the community to apply in the future for observations in this range of hour angles (HDF-S is located at 22:32:56.22, -60:33:02.69), and will add value to existing optical and NIR observations. This RA is the least subscribed range in long-baseline configurations. Having a sub-mm flux measurement or even flux upper limit could help studies of galaxy number counts, spectral energy distribution fitting, or simply providing high redshift galaxy targets to followup which are located in a field not yet extensively observed at these frequencies, and having a lower observational pressure at the telescope. | Galaxy structure & evolution | Galaxy evolution | 2024-07-25T02:20:36.000 |
| 379 | 2011.0.00661.S | 0 | High density gas tracers in a lensed submillimeter galaxy discovered in the H-ATLAS survey | Submillimeter galaxies (SMGs) constitute a population of high-redshift and heavily dust-obscured galaxies undergoing a phase of intense star formation, accounting for a large part of the total energy emitted in the Universe at far-infrared wavelengths. This population spans the peak epoch of star formation in the Universe, and is believed to be evolutionary linked to quasars and present-day ellipticals. Most star formation takes place in dense cloud cores, traced by molecular species such as HCN, HNC, and HCO+, which have some of the brightest lines after CO. Estimating the dense gas properties in SMGs using these lines is therefore essential in understanding galaxy evolution and the history of obscured star formation in the Universe. To date, the detection of such lines at high redshift has been limited mostly to the brightest quasars. We propose deep ALMA observations of the (3-2) transitions of HCN, HNC, and HCO+ in the lensed SMG HATLAS J090740.0-004200, at z=1.5746. Because of its compact size, its redshift, and large luminosity enhanced by gravitational lensing, this target is ideally suited for detecting the proposed transitions with ALMA Cycle 0, and also benefits from extensive ancillary data. These 3 lines will provide us the necessary diagnostics to constrain the total amount of dense gas and its physical properties, estimate the age of the starburst, and look for indications of AGN activity. We aim to obtain the first multi-line diagnostic set for dense gas in a high redshift SMG, showcasing the potential of ALMA to break new ground in the study of high redshift obscured star formation. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2014-06-16T17:06:00.000 |
| 380 | 2011.0.00010.SV | 0 | Science verification observation of HD163296 | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Disks around low-mass stars, Astrochemistry | Disks and planet formation | 2016-06-24T14:02:07.000 |
| 381 | 2012.1.00413.S | 5 | Feeding the massive black hole in the dwarf starburst galaxy Henize 2-10 | In the modern universe, supermassive black holes lie at the heart of most, if not all, galaxies with bulges. However, the birth and growth of the first "seed" black holes back in the earlier universe is observationally unconstrained. Recently, we have discovered an accreting massive black hole in the bulgeless dwarf starburst galaxy Henize 2-10 using observations from the VLA, HST and Chandra. With ALMA, we now have the first opportunity to study the dense gas presumably feeding the growing black hole in Henize 2-10, a nearby galaxy much like those in the infant universe. We propose Band 6 observations of HCN(3-2) and HCO+(3-2) in the most extended array configuration, which will enable us to probe dense gas within ~10 pc of the nuclear black hole. Sensitive, high-spatial resolution observations, only obtainable with ALMA, are crucial to ensure a clean separation and detection of the AGN-related emission among the nearby, bright star-forming regions. Due to the excellent uv-coverage of ALMA, these observations will also be sensitive to relatively large spatial scales in the galaxy, allowing us to map out the detailed morphology and kinematics of dense gas for the first time in Henize 2-10. Given the existing evidence for a possible interaction in this galaxy, the proposed observations have the potential to reveal any large-scale gas inflows that may be funneling fuel towards the black hole. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-12-08T00:29:19.000 |
| 382 | 2016.1.00168.S | 54 | Filament fragmentation in the high-mass Star Forming region G327.3-0.6 | With this proposal, we would like to investigate the evolutionary status of the filamentary cloud hosting the prominent hot molecular core G327.3-0.6. It is known that this filament hosting this core also includes a high-mass cold core, as well as other lower mass cores. The hot core is remarkable in that it neither displays discernible outflow activity not an H{\sc ii} region. We would like in this proposal to determine the N_2D^+/N_2H^+ ratio, which is a well established indicator of the evolutionary state. The goal is to determine the ages of the filament and its embedded cores, which lends itself well to modeling, because of the lack of feedback mentioned above. Ancillary data will allow the determination of density and temperature (from H_2CO), the freeze-out of CO (from its isotopologues), and of course also the kinematics of the filament. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-07-14T16:28:46.000 |
| 383 | 2017.1.01682.S | 28 | Measuring dust segregation across the rings of HD163296 | Thanks to ALMA we are discovering a variety of small scale structures in an incresing number of protoplanetary disks, that were previously thought to have a smooth distribution of dust surface density. The exceptional brightness of the HD163296 system allowed us to observe both the dust and gas emission at a ~0.2arcsec resolution, revealing a three bright rings at 1.3mm wavelength, and a CO depletion compatible with the presence of neptune-like planets (Isella et al. 2016). Recently acquired observations at 3mm are showing us hints of differential dust segregation across the dust structures, but the current resolution is not sufficient for separating the spectral index measurements inside and outside such structures, and optical depth effects at 1mm do not allow us to trace the true surface density in the inner regions of the disk (<50 AU). We ask for Band 4 and Band 3 observations at a matched resolution in order to resolve the spectral index (and therefore the maximum grain size) across the rings seen at 1.3mm, and attenuate the optical depth effects in the inner disk. | Disks around high-mass stars | Disks and planet formation | 2019-02-21T18:42:04.000 |
| 384 | 2018.1.01656.S | 11 | Resolving the Accretion Disk with Photoionized Outflow in O-Star Formation | In the formation of O-type stars, the mass accretion process in the face of intense radiative feedback is a critical problem. Accretion through a disk is a potential solution to circumvent this feedback. However, accretion disks exposed to radiative feedback, i.e., associated with photoionized regions, are not found yet. We propose a high-resolution imaging observation at 0.045" toward one of the most massive protostars. Our primary goal is, for the first time, to resolve the disk associated with the photoionized outflow down to the disk scale of 100AU. Our radiative transfer model is utilized to solve the degeneracy of dust and free-free emission in the continuum, revealing the density and temperature profiles of the disk-outflow system and the properties of the central massive protostar. As a by-product of the high-resolution imaging, we can include molecular lines and hydrogen recombination lines which trace disk kinematics, i.e., rotating and infalling motions, and the launching mechanism of the ionized outflow. Our proposed high-resolution observation will answer the long-standing question of how massive stars form in the presence of radiative feedback. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2020-12-10T00:00:00.000 |
| 385 | 2022.1.00513.S | 48 | Are fibers confined by gas accretion? | Fibers are recognized as the fine substructure of most nearby filaments playing a pivotal role on the gas fragmentation process in low- and high-mass star-forming regions. Despite their widespread detection, the origin of these dense structures remains under debate. For the first time, this proposal aims to investigate the more diffuse gas around the dense fibers inside the Integral Shape Filament in Orion previously identified by ALMA. Combining HNC and HCN observations in Band 3 (12m array) and Band 6 (ACA+TP stand-alone) at similar resolutions, this novel program aims to investigate the physical properties of the more diffuse gas surrounding these fibers. We will combine multi-line observations of both (1-0) and (3-2) lines with radiative transfer calculations to characterize the density structure, thermal properties, and gas kinematics around these fibers down to resolutions of ~2000 AU. With critical implications for our current description of the gas evolution inside molecular clouds, these new Cycle 9 observations will provide fundamental constraints on the dynamical evolution, mass accretion rates, and pressure confinement of fibers during the star-formation process. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-06-02T20:12:10.000 |
| 386 | 2018.1.00045.S | 21 | Circumplanetary ring system surrounding a distant planet around a Solar-type star? | ALMA Cycle 4 Band 6 resolved observations of the eccentric debris disk surrounding the Solar-type star HD202628 reveal a very narrow circumstellar ring at mm wavelengths, and, intriguingly, reveal a bright source just interior to this narrow ring. The best scenario is that this source is the signature of a circumplanetary ring surrounding the belt-shaping perturber, which we primarily aimed to characterize through its gravitational signature on the debris disk. If it were to be the case, this circumplanetary ring system would be the first of its kind ever directly observed. As revealed by its absence in Herschel/PACS observations, and similarly to Saturn's rings, this cold circumplanetary ring system would lack grains smaller than ~1mm sizes. Whilst the probability that this source is a background object is low, we can only unambiguously rule out this scenario with a second epoch observation and so we propose to observe again this target in Band 6 to determine whether it is co-moving with the star and confirm whether we are actually directly observing a circumplanetary ring for the very first time. | Debris disks, Exo-planets | Disks and planet formation | 2020-02-09T00:13:56.000 |
| 387 | 2015.1.00441.S | 21 | Revealing the Chicken-and-Egg Problem of the Onset of the Equatorial Density Enhancement in the AGB Mass Loss | We propose to address the long-standing Chicken-and-Egg problem of the onset of the equatorial density enhancement in dusty stellar mass loss during the asymptotic giant branch (AGB) phase. Here the issue is whether the central torus is the consequence of intrinsic bipolar outflows carving out a cavity that defines the bipolar axis or the origin of bipolar outflows steered into the intrinsic biconical openings. We will confront the issue by resolving the velocity structure and the relative 12CO/13CO distribution around the central torus embedded in the circumstellar envelope (CSE) of two representative proto-planetary nebulae (PPNe). We will look into how the CO outflow velocity field differs in the two PPNe having different optical morphologies, especially with respect to the latitudinal dependence of the CO ourflows. We also aim at resolving the longitudinal motion to see if the central torus exhibit the Keplerian rotation. The 12C/13C abundance ratio distribution can indicate if the wind material is in motion or in a pause, hinting at the presence of flows. Based on these pieces of dynamical evidence we will determine the role of the central torus during the AGB mass loss. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2017-09-13T16:26:57.000 |
| 388 | 2017.1.00582.S | 124 | Phosphorous chemistry in the winds of R Dor and IK Tau | The role of phosphorus in interstellar and circumstellar gas and dust chemistry remains unclear. Phosphorus monoxide (PO) and phosphorus nitride (PN) have been observed in the circumstellar environment of the oxygen-rich AGB stars IK Tau, R Dor, TX Cam, and R Cas, and the red supergiant VY CMa. PN, CP, CCP, HCP, and PH3 have been observed towards some carbon-rich evolved stars. The derived high abundances for PO and PN in the oxygen-rich winds cannot be accounted for by current chemical models. Furthermore, from the models, PS and PH3 are expected to be among the major P-carriers but these molecules have not been detected yet in oxygen-rich evolved stars. We propose to observe PO, PN, PH3, and PS in the circumstellar environments of IK Tau and R Dor and aim at constraining their spatial distribution and relative importance. A sensitive search for these molecules using ALMA will help quantify the total P-budget of the outflows, and constrain the efficiency of gas-phase reactions involving P, the depletion of P onto dust, and the formation on dust-grain surfaces of P-bearing species. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2019-01-31T19:01:22.000 |
| 389 | 2019.1.01324.T | 63 | Constraining Jet Formation and Evolution with X-ray Binaries | Relativistic jets launched by accreting black holes can affect star formation, galaxy evolution and even the distribution of matter in the universe. Therefore, it is essential that we understand the process of accretion and the physics of these accretion-fed outflows. Black hole X-ray binaries (BHXBs) provide ideal laboratories for probing jet phenomena due to their rapid (day-week) evolution timescales. In particular, broad-band spectral measurements of jet emission in BHXBs during bright outburst periods allow us to constrain the physical conditions in the jet, which can then be coupled to the properties of the accretion flow, probing the mechanisms that govern how jets are launched and quenched. The mm/sub-mm regime bridges a crucial gap between radio and IR frequencies, as data in this regime are essential when performing detailed spectral modelling. We propose targeting the next outbursting BHXB with ALMA ToO observations, to accurately measure the evolving mm/sub-mm flux. Coupled with our exceptional multi-wavelength coverage, we will constrain the dynamic broad-band spectral energy distribution in BHXBs with unparalleled accuracy. | Black holes, Transients | Stars and stellar evolution | 2022-10-22T00:00:00.000 |
| 390 | 2019.1.01436.S | 10 | What is the Environment of the Highest Accreting Black Hole at z>6? | The earliest quasars known in the Universe might have a "seed" problem: Their supermassive black holes already grew to ~10^9 M_sun, for observed accretion luminosity around the Eddington limit. Growth from intermediate- or even low-mass black hole seeds with <1000 M_sun requires growth-timescales comparable to the age of the universe at z=6 to 7, putting stringent constraints on seed black hole formation models. In contrast to this, our systematic search for z>6 quasars based on Pan-STARRS1 newly discovered a remarkable quasar at z=6.34, PSO J083+11: it has a lower mass black hole, log(M_BH/M_sun) = 7.9, but an extreme specific accretion rate: L_bol/L_Edd = 14. With a sustained rate like this it would have grown from small seeds to its current mass in only 50-100 Myrs. So how can this quasar have such high accretion? We want to use ALMA to create an inital map of [C II] and dust to (1) derive mass and extent of the cold gas reservoir around PSO J083+11, (2) search for potentially associated companions. Our goal is to trace the environmental conditions required for such extreme black hole growth, and specifically the differences to all other, lower accretion, early quasars. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-01-09T10:11:58.000 |
| 391 | 2022.1.01158.S | 0 | Searching for a Neutral Circumstellar Disk Sandwiched by Ionized Gas in the Hyper-compact HII Region G24.78+0.08 | One of the key questions about massive star formation processes is how massive protostars gain their masses despite the strong ionizing feedback. Theoretical studies have suggested that mass accretion continues through the "neutral" disk sandwiched by ionized regions even under ionization feedback. However, such a neutral disk sandwiched by ionized regions has never been discovered so far. We propose observations of the continuum emission, the H30alpha recombination line, and several molecular lines (H2O, SiO, etc.) toward the hyper-compact (HC) HII region G24.78+0.08 with ALMA Band 6. The primary goals are (1) to obtain more precise kinematics of the H30alpha line so that we can confirm the ionized disk, and (2) to examine the presence of the neutral circumstellar disk using molecular lines. If discovered, this will be the first example of a neutral disk sandwiched by ionized regions, providing direct evidence of the theoretical prediction, i.e., mass accretion still continues at the HC HII region stage via the neutral circumstellar disk. | High-mass star formation | ISM and star formation | 2024-12-08T13:16:01.000 |
| 392 | 2022.1.01649.S | 12 | Water cycles: tracing D/H in an embedded protostellar disk | The D/H ratio of water vapor has long been used as a key fingerprint to trace the origin of Earth's water. However, the overall understanding of water D/H in the solar system is uncertain. The classical paradigm indicates that deuterium fractionation is temperature dependent, which predicts an overall radial gradient (low D/H close to the star and higher values at greater distances). This gradient may be imparted on forming solar system solids. However, recent work shows plausible mechanisms for local deuterium enhancement. A pilot study of the HOPS-370 protostar and its disk offers a simple opportunity to test this theory. This source has a kinematically isolated 100 au disk as inferred from ALMA observations, along with NOEMA detections of H218O, HDO, and CH3CN (priv. comm.). The latter molecule is an excellent probe of the temperature. We propose to use ALMA and resolve the disk with multiple beams inside the water snowline to search for radial gradients in the water D/H ratio. | Intermediate-mass star formation, Astrochemistry | ISM and star formation | 2024-06-22T22:31:52.000 |
| 393 | 2017.1.01371.S | 34 | Imaging the water snowline in low-mass protostellar cores | Water is not only essential for life as we know it, it also plays an important role in the formation of stars and planets. With Band 5, ALMA has a powerful new option to image water in protostellar sources. A long-standing question is whether their inner regions, hot cores, are 'wet' or 'dry', i.e. whether the gas-phase water abundance is 1e-4, as predicted from ice desorption, or orders of magnitude lower. We propose to address this question by observing H218O toward four protostars in Perseus, doubling the number of sources for which water has been imaged. In addition, these H218O images will reveal the location of the water snowline. Imaging H13CO+ will allow us to confirm the spatial anticorrelation between H218O and H13CO+ predicted by chemical models and observed for NGC1333 IRAS2A. If confirmed in a larger sample, this will establish H13CO+ as a good tracer for the water snowline in sources where water itself is difficult to image (e.g., planet forming disks). | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-10-18T01:26:07.000 |
| 394 | 2018.1.00473.S | 114 | Mapping CO emission in galaxies from the JINGLE survey | JINGLE is a new large program on the JCMT that is mapping 193 nearby spiral galaxies. The sample has been selected to have extensive ancillary data from the UV to the far-infrared as well as resolved integral-field optical spectroscopy. We propose to use the stand-alone ACA to make CO(2-1) maps of the 20 brightest JINGLE targets observed so far in CO(2-1) with the JCMT. These ACA maps will allow us to measure the angular extent and radial profile of the CO emission, which will produce a more accurate estimate of the total molecular gas mass as well as resolve its spatial distribution, kinematics, and gas-to-dust ratio. We will also investigate the resolved Kennicutt-Schmidt law and CO Tully-Fisher relation. These JINGLE galaxies are interesting targets for the ACA because they are more gas rich than other resolved nearby galaxy surveys and already have global CO, HI, and dust data available. | Spiral galaxies | Local Universe | 2020-08-24T14:42:19.000 |
| 395 | 2015.1.00121.S | 49 | Molecular Clouds and Star Formation: Inner Disk of M83 | We propose an arcsecond resolution imaging of molecular gas in the entire inner disk of M83 (30 square-kpc). We will study molecular gas and cloud properties, star formation, their interrelation as well as relation to gas dynamics. M83 is the nearest face-on grand-design spiral galaxy with a stellar bar. Our imaging area contains both of the spiral arms and the entire bar. We will resolve individual GMCs at 20 pc resolution and achieve 10-sigma mass sensitivity of 1e4 Msun for beam-size clouds. Statistical properties of the GMCs will be anlyzed as a function of gas dynamical environment (e.g., circumnuclear, on/off bar, bar-end, and on-/inter-arm). We will also quantify using HST data the association of GMCs to young star clusters and HII regions. Our central question is : How do galactic structures such as the bar and spiral arms affect the properties of GMCs and subsequent star formation? Our unprecedentedly detailed wide-area observations will allow a significant progress toward its answer. The data will also serve as a base for multi-wavelength studies of M83 by the community. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2017-08-03T08:24:44.000 |
| 396 | 2013.1.00462.S | 11 | Highly excited CO lines in quasars at z>6 | We have detected the CO(17-16) emission line in a quasar at z=6.4 through the PdBI. This is the most excited CO transition ever measured in such distant galaxies. The detection of such high-J CO (HJCO) line allows to put strong constraints on the properties of the molecular gas at high-z. Moreover, this discovery suggests that HJCO lines may provide a sensitive, unique tool to infer the presence of X-ray faint or obscured super massive black hole (SMBH) progenitors in galaxies at z>6, thus shedding light on a key problem in cosmic structure formation. To test this exciting hypothesis it is necessary to verify that HJCO lines are specific signatures of high-z quasars. We therefore propose to observe five HJCO lines in three z>6 quasars for which ALMA Cycle 0 observations are already available. The success of our experiment will strongly support the idea that AGN activity is always associated with HJCO lines. The new capabilities offered by ALMA in Cycle 2 allow to open a new pathway for the discovery of SMBH progenitors in only 4.3 hours of total observing time. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2016-07-13T16:53:30.000 |
| 397 | 2021.1.00367.S | 275 | ACA Mapping of the Largest Supergiant HII Region in the Nearby Universe: 30 Doradus | The 30 Doradus region is the most extreme example of a supermassive HII region in the nearby universe, powered by its central R136 super star cluster. Surrounded by a complex of molecular clouds experiencing the disrupting effects of photoionization, winds, and compression by hot gas, only a small region in the very central core has been imaged with ALMA. We propose to map a 15'x15' area encompassing all massive star formation in the area and most of the dusty environments, using the ACA with a high-enough sensitivity to produce high quality 13CO information. This will allow us to study the broader environment of the star forming clouds, constrain the time scales for star formation and cloud disruption in this environment, and study the effects of feedback on the molecular material. The area selected for mapping has excellent ancillary data from the Hubble Tarantula Treasury Program and velocity-resolved [CII] from SOFIA. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2022-12-28T16:13:23.000 |
| 398 | 2017.1.00842.V | 0 | Lifting the Curtain in M87: From Accretion to Jet Formation | Understanding the processes of mass accretion and jet-launching in supermassive black holes (SMBH) is one of the central quests in modern astrophysics. The radio galaxy M87 contains the nearest and largest active SMBH, offering the best opportunity for probing the site of mass accretion and jet launching near a SMBH. Here we propose polarization imaging of M87 at 86 GHz with 7 Rs resolution, to determine the strength and topology of the magnetic field, detect the accretion flow and discriminate between two major jet launching scenarios (Blandford & Payne (BP) or Blandford & Znajek (BZ)). In combination with near-in-time space-VLBI imaging at 22 GHz (RadioAstron) and planned 230 GHz VLBI imaging (EHT), we aim to determine the frequency dependence of the polarization vectors, which in turn will allow us to determine the intrinsic B-field, corrected for Faraday rotation effects. Additional science goals are (i) the determination of the slope of the jet collimation profile, and (ii) the magnetization of flow and jet. The accurate measurement of the collimation profile will allow us to prove/disprove the reality of electromagnetic jet launching in M87 and help to determine the BH spin. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2020-11-20T00:00:00.000 |
| 399 | 2013.1.00450.S | 3 | Exploring the mass-loss history and the dust content in circumstellar nebulae around three magellanic luminous blue variable stars | The post-main sequence evolution of massive stars is ruled by mass-loss, through mechanisms that are still poorly understood. We propose to study the mass-loss history and the dust production in massive stars through observations of luminous blue variable nebulae (LBVNe). The possibility that the LBV mass-loss mechanism is independent of metallicity makes these objects among the best candidates for dust production in high redshift galaxies and for the interstellar medium enrichment in the early Universe. Some galactic LBVNe have been observed in a large spectral domain, but a paucity of data exists in the lower-metallicity environment of Magellanic Clouds, mostly because the IR instruments available have not been suitable for similar studies. However, our previous study evidenced the presence of dust in three magellanic LBVNe. We propose to observe with ALMA such objects in order to provide for the first time images of their dust content. Mass-loss history and physical parameters will be compared with those of galactic LBVNe in order to recover any differences due to lower metallicity. This study we will open new scenarios for the early Universe comprehension. | Luminous Blue Variables (LBV) | Stars and stellar evolution | 2016-08-26T12:34:36.000 |
| 400 | 2024.1.00780.S | 0 | GQ Lup unveiled: Probing the Evolution of a Circumplanetary Disk | GQ Lup hosts a well-known accreting 10-30 MJ companion that interacts with the surrounding circumstellar disk. The companion has been confirmed to harbor a circumplanetary disk (CPD), offering a unique opportunity for comprehensive study across a wide range of wavelengths from the near- and mid-infrared with JWST to radio frequencies with ALMA. This proposal aims to provide the first empirical insights into the physical properties of a CPD by leveraging observations from NIRSpec, MIRI, and ALMA Band 7. These observations, coupled with radiative transfer models, will be sensitive to the geometry of the CPD, the properties of its grains and the presence of pebbles in optically thick or thin configurations. Moreover, GQ Lup presents a rare chance to investigate planet-disk interactions. Notably, GQ Lup B stands as the sole directly imaged companion with a documented orbit which is interacting with its parent disk at a separation substantial enough to resolve the kinematic perturbations it imparts on the surrounding gas. Through high-resolution observations of 12CO and 13CO, we aim to validate and refine our current modelling of planet disk interaction. | Exo-planets | Disks and planet formation | 2025-10-14T13:34:40.000 |
| 401 | 2015.1.00840.S | 0 | B-field maps vs jet rotation: the ultimate test of MHD angular momentum extraction | Protostellar jets launched magneto-centrifugally are believed to remove the excess angular momentum from the accretion disk of young stars. To test this theory observationally, we propose to examine the relationship between jet rotation signatures recently detected close to the star and the magnetic field configuration that can be mapped with ALMA. Class II systems emerged from their formation envelope are ideal for this study. Cycle 3 ALMA polarimetric capabilities allow us to map the dust polarization continuum, and finally the B-field geometry, in T Tauri disks at a spatial resolution appropriate to a meaningful model comparison. We propose to observe two targets, DG Tau and CW Tau, in band 7 with 0.15 arcsec resolution. These are the only systems in which both jet and disk rotation have been measured, and the continuum is bright enough to detect polarization properly. In both cases the rotation senses of disk and jet have been found to match. The results will be compared with magneto-centrifugal models which have predicted jet rotation at observd levels. This will constitute the most powerful test to date of jet launching as a solution to the angular momentum problem. | Outflows, jets and ionized winds | ISM and star formation | 2021-06-30T20:21:06.000 |
| 402 | 2017.1.01690.S | 39 | Using eclipses to determine the size of a neutron star jet | We have recently discovered a new gamma-ray loud low-mass X-ray binary, 3FGL J0427.9-6704. The X-ray and radio properties of this source suggest it is a transitional millisecond pulsar in the accreting state. Uniquely among members of this class, this source shows optical, X-ray, and gamma-ray eclipses, allowing precise measurements not available for non-eclipsing systems, such as the binary component masses and constraints on the emission geometry. Here we propose ALMA observations of two separate eclipses, taken at different frequencies, to determine whether the mm emission is eclipsed and for how long, thereby providing a unique probe of the size scale and launching radius of the jets from a neutron star. | Pulsars and neutron stars | Stars and stellar evolution | 2019-01-24T19:07:46.000 |
| 403 | 2018.1.00326.S | 26 | The Rosette protocluster: testing cluster formation theories | We propose ACA + TP Band 3 mosaic observations of the dense N2H+ gas in the Rosette protocluster. These data will sample physical scales down to ~0.08 pc at the distance of the Rosette (1.4 kpc). In combination with our recently accepted APOGEE2-S data measuring the young star radial velocities and our Herschel mass maps, we will use the dense gas spatial location and kinematics to test several radically different models for the formation and evolution of gas-dominated protoclusters: the "Slingshot", "cold collapse", gravity-dominated collapse, and the cluster merger scenario. We will identify both the successes and failure modes of these, providing essential constraints for theoretical investigations and numerical simulations of the formation and evolution of stellar protoclusters in the era of ALMA, APOGEE, and Gaia. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-10-23T20:45:31.000 |
| 404 | 2023.1.01084.S | 10 | Identifying targets for cross-checking blackhole mass measurements | The co-evolution of supermassive black holes (SMBHs) and their host galaxies is crucial to galaxy evolution. However, though fundamental to this co-evolution, scaling relations are built on a relatively small number (<200) of direct SMBH mass measurements and a variety of methods. In the ALMA era, a new method of probing the near-Keplerian rotation of CO discs around SMBHs shows great potential. To further cross-check the CO dynamics method with other methods, we propose standalone ACA observation of 22 galaxies with 18 hours in total to search for suitable targets for subsequent high-resolution follow-up. The sample is from a comprehensive compilation of SMBH masses from different methods and is required to exhibit regular dust features (in HST images) as an indication of regularly rotating CO discs, among other criteria. Based on success in the last cycle, we will analyse the morphology and kinematics of molecular gas, thus identifying promising targets for the next step. As a by-product, we will study molecular gas properties on kpc scales with ACA data, again paving the way to and selecting suitable targets for future cloud-scale studies. | Galactic centres/nuclei | Active galaxies | 2025-03-17T12:24:15.000 |
| 405 | 2022.1.00216.S | 49 | Blowing in the wind: An ALMA multiband study of dust in two protostellar winds | The aim of this proposal is to study the interface between protostellar disks and jets, and test the hypothesis that dust can be carried away at this interface via a wind. We have undertaken an extensive search of the ALMA Science Archive, and we found promising evidence for dust continuum extensions in a handful of sources, that we now wish to expand with consistent observations in terms of angular resolution (corresponding to 20 au) and multi-band coverage. Beyond the question of "is dust being launched into protostellar winds?" we seek to address how much dust can be launched into a wind, as compared to the mass of the disk; how far from the disk this dust can be observed; and the dust grain size distribution in the wind launching region. Not only do we aim to constrain if winds can remove dust grains from a disk, but quantify at what level winds affect early disk formation and evolution. The scenario probed here has important impacts on the mass, composition, and evolution of the disk, which is ultimately the reservoir for planet formation. ALMA is the only facility with sufficient angular resolution and multi-band coverage for this study of sub-mm-size dust grains. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2024-02-17T21:16:57.000 |
| 406 | 2018.1.01594.S | 52 | Intensity Mapping of High Redshift Molecular Gas at 3mm | Molecular gas is central to the formation of stars in galaxies, but at high redshift, it has been well-studied in only a handful of the most luminous systems. Recent surveys with ALMA have begun to probe the molecular gas of more "common" galaxies, although these surveys have remained limited in volume. We therefore propose to use the ACA to perform a 3mm intensity mapping study, over a survey area of 15 sq arcmin , with spectral coverage over vast majority of Band 3. With these data, we will be capable of probing the mean line emission (and molecular gas content of) galaxies at z=1-5. The proposed measurement will additionally leverage line intensity mapping efforts with both the ACA, VLA, and SMA, enabling cross-correlation between a multitude of line species. | Surveys of galaxies | Galaxy evolution | 2019-12-18T21:35:15.000 |
| 407 | 2018.1.00632.S | 6 | Does the magnetic field regulate the collapse in the massive core G31.41+0.31? | The most clear example up to date of an hourglass-shaped magnetic field morphology in the high-mass regime is that of the very massive (>100 Msun) and luminous (2e5 Lsun) hot molecular core G31.41+0.31. With this ALMA proposal we want to establish the role of magnetic fields in the collapse of each embedded (proto)star in G31.41+0.31 by observing in Band 3 and 6 the polarized dust continuum emission at an angular resolution of 0.08 arcsec. This will allow us to resolve the dust continuum emission, achieve a spatial resolution of about 600 au, and thus, trace the magnetic field down to circumstellar scales. Our main goals are: (i) to study the magnetic field morphology towards the embedded (proto)stars and check whether the self-similarity observed at core scales (1 and 0.20 arcsec resolution) still holds at 0.08 resolution; (ii) estimate the magnetic field strength (in the plane of the sky) and the mass-to-magnetic flux ratio, to determine whether magnetic fields provide enough support against gravitational collapse | High-mass star formation | ISM and star formation | 2020-12-26T17:23:00.000 |
| 408 | 2012.1.00395.S | 0 | Warm Deuteration of HCN in Orion-KL | High deuterium fractionation has been observed in different environments in the ISM, but its chemical pathways are not yet fully understood. In particular, deuteration of HCN in the Orion Molecular Cloud has been explained using both warm gas-phase chemical models and desorption from grain surfaces by different authors. Herschel/HIFI data in Orion KL show high-J lines arising from DCN, revealing the high density and temperatures at which this species is produced. On the other hand, DNC has only been marginally detected through lower J transitions at the IRAM 30m telescope. Recently, ALMA SV data in Orion has been released. Within the 214-246 GHz scan, the DCN and DNC J=3-2 transitions show different spatial distribution. Both the different observed D/H ratios and emission distributions indicate deuteration processes of these two isomers may be different. However in order to obtain the D/H variation within Orion-KL for each species and determine the main deuteration source component, we need the main species which transitions at Band 6 lie outside the SV spectral scan. Besides we would like to map the emission of one of the high-J lines observed by HIFI, only available to ALMA at high angular resolution in the Band 9 frequency range. Thus, we will probe the high density and temperature components where this species is present. The proposed observations will greatly improve the current chemical models by identifying the deuteration processes at work (grain desorption vs warm gas-phase), and will provide a better knowledge of the physical and chemical properties of Orion-KL source components. | Astrochemistry | ISM and star formation | 2015-03-17T19:15:52.000 |
| 409 | 2018.1.00181.S | 61 | Searching for Nitrogen bearing organic Formamide: Bridging the Disk composition with Comet 67P/Churyumov-Gerasimenko | Confirmation of the presence (or absence) of complex organic molecules (COMs) in protoplanetary disks is of ultimate astrobiological importance because it links the possibility of forming prebiotic molecules in the disk to their survival into the planets and other objects such as comets and asteroids. The ALMA era has shed light on COMs in disks with the detections of gas phase methyl cyanide, CH3CN, in MWC 480, and methanol, CH3OH, in TW Hya. Formamide, NH2CHO, is the next unique N/O/C bearing COM awaiting detection in disk. It has great pre-biotic potential due to its peptide link (-NH-c(=O)-]. Also, it is the most abundant COM with respect to water on the material of the comet 67P observed recently by the spacecraft Rosetta. We propose to deeply search for NH2CHO toward the nearby bright disk around the Herbig Ae star HD 163296. A detection will provide a clear understanding about the physical and chemical origin of NH2CHO in the comet 67P. Even in the case of a non-detection, the high sensitivity will provide stringent upper limits which inturn will put strong constraints on theories on chemical heritage of comet building material as well as traditional disk chemical model. | Disks around low-mass stars | Disks and planet formation | 2021-07-02T00:00:00.000 |
| 410 | 2015.1.00678.S | 107 | Survey of CO Snow Lines in Solar Nebula Analogues | Snow lines, or condensation fronts, of major volatiles in protoplanetary disks are proposed to regulate planet formation efficiencies as well as planet and planetesimal (comet) bulk compositions. Observational constraints on the location of major snow lines in disks are key to anchor models of planet formation, to constrain the orgins of chemical and physical structures in our Solar System and in exo-planetary systems. Recent Cycle 0 and 1 ALMA observations have demonstrated that high spectral and spatial observations of N2H+ emission enable direct imaging of the CO snow line location in protoplanetary disks. We propose to use this powerful chemical tool to survey the CO snow line radii in a sample of disks around Sun-like stars - Solar Nebula analogues, and probe the response of the CO snow line location to the stellar and disk characteristics (stellar age, incident radiation field, and cavity size), which should regulate the bulk elemental composition of planets and planetesimals formed in the disks. | Disks around low-mass stars | Disks and planet formation | 2017-12-29T16:15:46.000 |
| 411 | 2019.1.00087.S | 9 | Searching for the oasis in the planet-forming desert | Water is strongly connected to the emergence of life and the formation of planets. Yet, we still do not know how water is delivered to planet-forming disks. The total water abundance relative to hydrogen is expected to be close to 1e-4. However, observations of the warm and cold water reservoirs in mature protoplanetary disks indicate orders of magnitude lower values than the predicted abundance. Similarly, low water abundances have been derived toward a handful of embedded protostars. In order to quantify the water content during the formation of planet-forming disks, we propose to perform a systematic search for interstellar and circumstellar water in 16 low-mass protostars at 10 au resolution. We will explore a range of envelope masses, disk properties and luminosities. The optically thin H218O 203 GHz line in Band 5 has been shown to be effective in the search for water . With the proposed program we will determine whether the young embedded planet-forming disks are rich in water vapor (wet). The direct implication of dry planet-forming disks is that water is delivered to planetesimal-forming zones by large icy dust grains in the earliest stages of star formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2022-09-23T10:24:03.000 |
| 412 | 2022.1.00810.S | 29 | Spatially-resolved clump properties and gas turbulence in local analogues to high-z galaxies | It still remains unclear what drives strong star formation and large turbulences in high-z star-forming galaxies. To answer this question, one must study the detailed physical processes in high-z galaxies at small clump scales. However, it is extremely difficult to resolve clumps in high-z galaxies due to their large distances. We thus propose high-resolution (~0.1" or ~200pc) ALMA CO(1-0) observations in two analogues at z~0.1 that share many physical properties of high-z galaxies. An innovative analytic model of clump-clump collisions to quantitatively explain the observed clump properties and turbulence in high-z galaxies has been developed in our recent study. With our proposed observations and newly developed collision model, we aim to (1) link clump properties and gas turbulence to disc dynamics; (2) measure the SF law at clump scale and quantify the star formation efficiencies of individual clumps; (3) test our collision model in local analogues to high-z disc galaxies; and (4) test whether star formation is induced by clump-clump collisions. The proposed study here will greatly help with the interpretation of high-z observation data. | Galaxy structure & evolution | Galaxy evolution | 2024-07-12T09:51:24.000 |
| 413 | 2018.1.00101.S | 416 | The initial gas flow towards extremely young high-mass clumps | The initial conditions of high-mass star formation (HMSF) are still unclear. One of the key questions is how gas is fed from the parental high-mass clumps to the descendant cores. Small scale (<1pc) infall is barely reported towards extremely young (<10^4 yr) high-mass pre-/proto-stellar objects, due to the lack of candidates and the limit of sensitivity and spatial resolution of previous observations. We select a sample of 16 extremely cold, dense clumps (<1Lsun/Msun) in the southern hemisphere, which locate in 70 micron dark clouds, and have shown infall and shock signatures at 1 pc scale. Based on our previous observations, these sources are prime targets for initial conditions study of HMSF. We aim to investigate: (1) the physical structure of each clump by using H13CO+(1-0) and 3.4 mm continuum to trace the dense cores down to <0.1 pc; (2) the infall at <1pc scale along the line-of-sight and the along filament by using H13CO+/HCO+(1-0) pair, and characterise the averaged infall rates towards the internal high-/low-mass cores; (3) the shock origins by imaging SiO (2-1), and characterise the shock energy and outflow properties from extremely young high-mass protostellar objects. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2021-09-01T00:00:00.000 |
| 414 | 2023.A.00042.S | 0 | The close approach of Near-Earth Asteroid 2024 ON: a once-in-a-decade opportunity | On September 17, 2024, Near-Earth asteroid 2024 ON will approach the Earth at a distance of only 0.0068 AU, or just about 1 million kilometers. This is a rare opportunity to characterize a Potentially Hazardous Asteroid through a variety of techniques. A continuum detection with ALMA will produce the thermal data point needed to perform full thermophysical modeling of 2024 ON, allowing one to derive the thermal inertia on an asteroid smaller than 0.5 km. Observations should be performed between September 20-28. | Solar system - Asteroids | Solar system | 2025-04-02T19:11:00.000 |
| 415 | 2016.1.01146.S | 22 | Assessing Stability of Filamentary Accretion Flows around the Protocluster G14.114-0.574 | We propose to investigate the dynamical stability of filamentary accretion flows in the remarkable IRDC complexes, M17 SWex, where a delayed onset of massive star formation was reported in two hubs at the convergence of multiple filaments of parsec length. We plan to conduct a 54-pointing mosaic around one of the two hubs, G14.114-0.574, in the C40-2 configuration in Band 3. Although filamentary structures are ubiquitous in molecular clouds, basic observational constraints are needed to clarify the role of filaments in the mass assembling process. We have analyzed the delivered N2H+ (1-0) data of our Cycle 2 project and successfully derived the kinematics in the filaments. Yet the limited sensitivity and insufficient short spacing data render doubtful fitting results in many parts of the filaments and hinder further investigation of virial equilibrium, which requires reliable fitting for line width and multiple velocity sub-structures. Hence, we request sensitive 12-m array observations together with the ACA to recover short spacing flux. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-06-15T11:37:18.000 |
| 416 | 2017.1.00248.S | 18 | MOLECULAR CLOUDS AND STAR FORMATION IN BAR OF NGC1300 | This proposal challenges the long-standing problem in barred galaxies that is why star formation efficiency is much smaller in bar regions than spiral arm regions. Recent high resolution numerical simulations suggest that star formation is suppressed by high velocity cloud-cloud collisions in the bar regions. Cloud collision makes cloud cores, but the high velocity collision causes too short duration for the cores to grow large enough for massive star formation via gas accretion. We detected CO(1-0) emission towards bar and arm regions of the prototype strongly barred galaxy NGC 1300 for the first time with the Nobeyama 45-m telescope. The observed emission line profiles in the bar and arm are very similar to those of the high resolution simulations, supporting this new scenario. Now we need ALMA observations to test the new scenario by identifying individual molecular cloud and deriving relative velocity distribution of the clouds. We stress that the understanding of physical cause for star formation by cloud collision is also very important to unveil galaxy evolution and formation at high redshifts. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2019-04-14T10:01:11.000 |
| 417 | 2015.1.00019.S | 18 | Resolving the star-forming ISM at z~2-3 | In this resubmission of our highly-ranked and approved (but unobserved) Cycle 2 project, we propose resolved (0.4"), matched-resolution mapping of the CO, [CII], and underlying dust continuum in a carefully selected sample of z~2-3 galaxies from our Cycle 0 870um ALESS survey of >100 submillimeter galaxies. Our recently completed intensive spectroscopic follow-up campaign has enabled us to meticulously identify 4 SMGs with redshifts that allow us to observe both low-J CO and [CII] with ALMA. In addition to providing tight constraints on gas masses, SF efficiencies, kinematics, and PDR models, these observations will reveal the fundamental relationship between molecular gas and star formation (`Kennicutt-Schmidt law') on ~kpc scales. Critically, they will also allow us to test how well [CII] correlates with the cold molecular gas reservoir probed with CO. This is imperative, as [CII] will be the main line for studying the star-forming ISM at even higher-z. These detailed case studies, which were prohibitively expensive before ALMA, are an essential complement to larger statistical studies of individual tracers and integrated properties. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-01-12T05:00:51.000 |
| 418 | 2022.1.01762.S | 0 | Core-Connecting Streamers -- A General Feature? | B-field stabilized streamers, connecting to cores in high-mass star-forming regions, are a potentially general feature and a way to accrete material onto central objects. First observations in W51 e2 are supporting this scenario. We propose 0.1" resolution dust continuum polarization observations towards 2 more sources, G34 and W51 North, which hint in their 0.26" resolution detections the beginning of a network of streamers. With the proposed observations we will (1) search for a core-connecting network of streamers and analyze the stabilizing role of the B-field along streamers, and (2) search for the imprint of disks onto the B-field morphology. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-01-23T01:18:49.000 |
| 419 | 2021.1.00100.S | 10 | [CI] observation of the overlap region in the Antennae galaxies | Photon dominated regions (PDRs) are key regions in the study of the interstellar medium because they are the interfaces between molecular gas, where stars form, and the surrounding galactic medium. The Antennae galaxies provide a unique laboratory to study the PDR model that applies to an intense star forming environment which occurs over kpc scales. We propose the [CI] (1-0) observation of the overlap region of the Antennae galaxies using the 7m array of the ACA. The primary goal of this project is to investigate the spatial distribution and kinematics of [CI] and CO at a 300 pc scale and characterize the PDR model which is appropriate for an intense star forming region in the overlap region. An important application of the outcome of this project is the PDR modeling of high-redshift galaxies, whose characteristics of the PDR/ISM are now being intensively studied using ALMA. We will also derive the molecular gas mass from the [CI] intensity and compare to the same quantities derived from CO (1-0). This is the first attempt to reveal the distribution of [CI] emission in the overlap region, and a necessary step toward future high resolution observations. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2023-12-20T02:00:33.000 |
| 420 | 2015.1.01353.S | 47 | What is the origin of spiral arms in the disk of HD 142527? | In Cycle 0, we discovered CO spiral arms extending out to 500 au in the outer disk of HD 142527. Surprisingly these spirals are very faint in CO (3-2), but brighter in CO (2-1), with temperatures as low as 10 to 15 K. We propose to confirm such low temperatures in HD 142527, and put deep limits on the continuum so as to test for low dust-to-gas mass ratios, that may explain the detection of CO gas colder than the freeze-out temperature (18 K). The new measured dynamics of the gas in the spirals will allow us to put conclusive constraints on their origin. In particular, the new observations of the spirals will also be confronted to our novel hypothesis of spirals launched by the shadows cast by the inclined inner disk. | Disks around high-mass stars, Exo-planets | Disks and planet formation | 2018-01-07T14:48:46.000 |
| 421 | 2023.1.01101.S | 0 | ACA CO(1-0) mapping of Stephan's Quintet | Compact galaxy groups offer a unique opportunity to investigate the impact of galaxy harassment and interaction on gas dynamics and star formation (SF) in a dense environment. Stephans Quintet (SQ; 89 Mpc) is a well-known compact galaxy group and a natural laboratory to investigate the process of the removal of gas from galaxies and the triggering of SF in this gas because group members are HI deficit and many inter-galactic SF regions are observed. However, although multi-phase gas data (e.g., HI, warm H2, ionized gas, and hot plasma) are available, a CO map across the entire group is currently lacking. Thus, we propose high accuracy ACA (7m+TP) CO(1-0) mapping across the entire group to completely characterize the spatial distribution and velocity structures of molecular gas in the SQ. Making maps of SF efficiency (SFE) and the ratios of various gas phases, we will reveal the impact of galaxy interaction on the SFE in the member galaxies, the relationship among the HI, molecular gas, and SF in the tidal tail, and the molecular gas formation process and required physical conditions of the gas to induce SF in collisional shock front. | Galaxy groups and clusters | Cosmology | 3000-01-01T00:00:00.000 |
| 422 | 2011.0.00004.E | 0 | Vela Pulsar J0835-4510 | ALMA engineering data release. | 2018-07-10T12:50:54.000 | ||
| 423 | 2023.1.00133.S | 0 | Probing the physical conditions of dust-obscured galactic nuclei at high redshifts with the H2O Jupper=4 lines | The progenitors of today's early-type massive galaxies are thought to be luminous dusty galaxies at high redshifts. The goal of this proposal is to further our understanding of this evolution by observing the H2O 422-413 and 423-330 lines at 1208 and 448 GHz in high-z lensed ULIRGs and HyLIRGs to 1) reveal whether and how the nuclear regions of this high-z population resemble their local ULIRG counterparts; 2) model the H2O lines together with the far-IR continuum to better understand the structure of the ISM and the SED. These J=4 lines are radiatively excited and probe the nuclear regions where the dust is optically thick even in the far-infrared, enabling the estimation of the dust optical depths, IR luminosities, effective sizes, structure, and luminosities and gas mass surface densities of the nuclear regions. Our sample includes the brightest high-z Dusty Star Forming Galaxies (DSFGs) at Cosmic noon observable with ALMA in both H2O Jupper=4 lines (3 ULIRGs, 3 HyLIRGs, and 1 QSO), all well studied in low-lying H2O lines, CO, continuum, and lensing. | Galaxy structure & evolution | Galaxy evolution | 2025-04-01T20:20:37.000 |
| 424 | 2024.1.00826.S | 0 | Of Dust and Dots: ALMA's View of the Brightest of JWST's Little Red Dots | One of the most surprising early JWST findings is a high abundance of Little Red Dots - very red and compact 3 | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 3000-01-01T00:00:00.000 |
| 425 | 2024.1.00844.S | 0 | CO Excitation Across the Local Galaxy Population | Here, we ask for the remaining 12m+7m+TP time to complete a partially executed Cycle-9 program: Extragalactic surveys increasingly use CO(2-1) to trace molecular gas. However, this relies on converting to the fundamental CO(1-0) line, and many studies assume average CO(2-1)/CO(1-0) line ratios (R21). Recent studies have found significant variation in R21 both across and within galaxies. This has implications for interpreting star formation scaling relations and characterizing molecular gas. Previous R21 studies were limited to poorer resolution and calibration uncertainties, preventing deriving firm quantitative conclusions. Here, we propose new CO(1-0) observations to construct the first well-resolved, well-calibrated, and sensitive survey of R21 across a representative sample of 17 nearby galaxies. We will use public multiwavelength data to relate R21 variations to local conditions, galactic structure, and molecular cloud properties. ALMA observations are crucial due to their high resolution (~3 arcsec) and calibration stability. These observations will have significant implications for key scaling relations and can be used to anchor large past and future CO(2-1) surveys. | Surveys of galaxies | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 426 | 2016.1.01308.S | 61 | Do Hyper-Luminous Dusty Quasars at z=2.5 Live in Massive Gas-Rich Disks? | Newly discovered hyper-luminous, dusty broad-line quasars are likely progenitors of the most massive black-holes today. They are seen during assembly at z~2.5, as they are fuelling their enormous black-holes from giant gas reservoirs. We detected 4/4 of these quasars in CO(3-2) in Cycle 3. Two have gas emission extending to 20 kpc and are ideal for resolved imaging. Dynamical modeling hints at the presence of a massive gas-rich disk in one quasar although the internal dynamics of the disk are unconstrained. In the other system, we detected CO(3-2) in two mm-bright galaxies within 200 kpc of the quasar, signifying that it sits in a massive over-density. In this proposal we will carry out a comprehensive investigation of the dust, gas and ISM properties in these 2 unique quasars to discriminate between disk and merger origins for the assembly of the largest supermassive black holes. Our goals are: (i) high-resolution imaging of the CO(3-2) emission for full dynamical modeling of the quasar hosts (ii) CO(7-6) and [CI] detections in Band 6 to constrain the excitation conditions in the ISM and (iii) dust continuum detections in Band 6 to better constrain the dust SED and dust mass. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-05-27T19:06:28.000 |
| 427 | 2017.1.01557.S | 54 | Elucidating the origin of small high-velocity compact clouds in the central 10 pc of our Galaxy | The central molecular zone of our Galaxy harbors a number of high-velocity compact clouds (HVCCs), which are a peculiar population of spatially compact (d < 10 pc) molecular clouds with extremely broad velocity widths (dV > 50 km/s). We have recently discovered two small (d ~1 pc) HVCCs (sHVCCs) in HCN J=4-3 and J=3-2 maps obtained with the JCMT. Both of these sHVCCs have similar physical properties, emanating from larger dense clouds in the position-velocity spaces. One has a faint counterpart in a Paschen-alpha image. In order to uncover the nature and the origin of these sHVCCs, we propose high-resolution observations in HCN J=4-3 and H26 alpha lines. The possible origin of the sHVCCs is (1) outflow from a deeply embedded massive protostar, (2) supernova explosion in the recent past, (3) cloud-cloud collision, or (4) high-velocity plunge of an invisible massive compact object into a molecular cloud. The ALMA images enable us to discriminate which process has formed the sHVCCs. This project should contribute to our understanding of these anomalous objects which could belong to a previously unrecognized population. | Galactic centres/nuclei | Active galaxies | 2019-05-17T03:34:36.000 |
| 428 | 2018.1.00219.S | 107 | Stellar feedback and gas scaling relations in nearby metal-poor dwarf starbursts | Feedback from accreting black holes and from massive stars and supernovae has acquired a fundamental role for our understanding of galaxy evolution. Recent simulations suggest that stellar feedback governs gas scaling relations, but there are currently few observational constraints for the low-mass metal-poor galaxies most vulnerable to feedback, because of their small potential well. We propose ALMA maps in 12CO(1-0) of three nearby, metal-poor dwarf starbursts, with HI maps and well-defined star-formation histories. These galaxies harbor super-star clusters, and well-documented outflows in neutral, ionized, and hot gas; we are missing the cool molecular component. Molecular gas is important for understanding feedback as it represents the reservoir for star formation. With the CO morphology and kinematics, we will be able to quantify the effects of stellar feedback on the gas scaling relations as predicted by recent simulations. By comparing gas stability to collapse against metallicity-weighted gas column densities, we can distinguish between conflicting model predictions as to the mechanisms driving the conversion of gas to stars in metal-poor galaxies. | Dwarf/metal-poor galaxies | Local Universe | 2020-02-14T20:41:48.000 |
| 429 | 2016.1.01209.S | 21 | HSC DSP Lens | Double source plane gravitational lenses are rare alignments of a massive galaxy with two background sources at distinct redshifts. The two source planes provide constraints on cosmology and galaxy structure beyond that of typical lenses by breaking degeneracies between parameters that vary with source redshift. These systems are valuable, but only a handful are known. We have discovered the first such lens in the Hyper Suprime-Cam survey and have spectroscopically confirmed both source redshifts. Furthermore, one image of the most distant source is split into a pair of images by an undetected mass component, suggesting the presence of a satellite galaxy. In order to better understand this system, we need an accurate lens model, accounting for the effects of both the main lens galaxy and the intermediate source. ALMA's high resolution will identify multiple star-forming regions in the outer source, allowing us to use its surface brightness distribution as constraints on our model and also constrain the substructure responsible for the splitting of the brightest image of the background source. With ALMA, we will take full advantage of the wealth of information from this system. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2018-12-06T06:09:15.000 |
| 430 | 2012.1.00953.S | 1 | ALMA Observations of the z=8.23 Host Galaxy of GRB 090423: Obscured Star Formation at the Dawn of Time | The potential of gamma-ray bursts as powerful probes of the high redshift universe has now been demonstrated with the discovery of bursts at z~8-9. The redshifts are highly secure thanks to the extreme brightness of the near-infrared afterglows (~1000 times brighter than galaxies at the same redshift) and their intrinsically featureless spectra, which provide a clear detection of the Lyman-alpha break. Here we propose ALMA band 6 observations of the host galaxy of GRB090423 at z=8.23, one of the two highest redshift spectroscopically-confirmed objects in the universe. This is an excellent target for early ALMA observations of the most distant galaxies since unlike the growing number of z~8 candidate galaxies from Hubble, its redshift is secure. We previously searched for the host with Hubble (10 orbits) and Spitzer (72 hours) but it was not detected. The proposed ALMA observations will reach an effective depth of 10 times better than Hubble and Spitzer, and will reveal the host if it has a luminosity of ~2e11 L_sun (similar to some other GRB hosts with mm-band detections). A detection will be a spectacular demonstration of ALMA's ability to reach the most distant galaxies, during the epoch of cosmic re-ionization. Even a non-detection will place better constraints on the nature of the galaxy than available from Hubble and Spitzer data, a testament to ALMA's power. | Gamma Ray Bursts (GRB) | Cosmology | 2015-04-16T19:00:44.000 |
| 431 | 2011.0.00008.SV | 0 | Science verification observation of Centaurus A | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Galactic centres/nuclei, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-06-24T14:02:07.000 |
| 432 | 2013.1.01029.S | 16 | Filleting the Filament: Quiescent and active gas in a high-contrast IRDC | Herschel gave us a plethora of filamentary structures based on column density maps. For assessing the dynamics of star formation therein we need to investigate the gas motions. We conducted a Herschel study towards 45 high-mass star-forming clumps. A striking object is the filamentary IRDC 316.72+0.07, attaining high peak column densities (>10^23 cm^-2) and low dust temperatures (<14 K). The Herschel data show more chaotic column column density structures in parts of this IRDC. The ALMA observations are guided by our previous single-dish molecular line mapping. We plan to mosaic the IRDC with ALMA at 3 mm. We want to probe the quiescent gas with N2H+, and the more active turbulent gas with HCO+/H13CO+. Objectives: 1) Trace the distribution and kinematics of quiescent gas. Are there hints for coherent velocity structures, with gas gradually decoupling from the turbulent gas and proceeding with gravitational collapse? 2) Understanding the dynamics of the active dense gas. Is there infall of inter-clump material onto the dense filament on larger scales? The kinematics of the gas on scales of 4" will then be compared to numerical simulations of filament formation and converging flows. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-01-18T00:00:00.000 |
| 433 | 2021.1.00199.S | 35 | Systematically Measuring CO Emission of Double-Barred Galaxies | We propose to initiate a systematic and reliable study on molecular gas in double-barred galaxies. The inner bar in double-barred galaxies is one of the mechanisms to drive gas inflow to fuel active galactic nuclei. However, it is still unclear whether and how much gas is needed to maintain a long-lived inner bar. Previous studies were unable to provide reliable results due to the difficulty to identify true double-barred galaxies and inadequate sensitivity and spatial resolution to measure the gas mass in the entire galaxy as well as in the inner bar region. To remedy this situation, we propose to obtain the CO line emission of seven double-barred galaxies which have been confirmed to have a unique feature called sigma-hollows. This feature identifies them as true double-barred galaxies. Using these ALMA observations, we will be able to provide reliable constraints of the gas mass on theories to shed light on the formation of double-barred galaxies. Our data will also provide important information for future studies to investigate the gas properties in double-barred galaxies, such as the gas inflow rate and the gas viscosity, which require higher spatial and velocity resolution. | Surveys of galaxies | Galaxy evolution | 2024-03-22T23:34:58.000 |
| 434 | 2023.1.01246.S | 0 | The cold chemistry of protostellar hot corinos | The emergence of complex organic molecules in the interstellar medium is a fundamental puzzle of astrochemistry. Observations of these species toward prestellar cores and large-scale protostellar envelopes demonstrate that many of these species are formed in such cold regions. In particular, observed differences between different types of organics toward prestellar cores highlight the importance of the conditions and dynamical evolution in the natal environments for the ensuing chemistry. We propose a program to link between the large-scale, cold (10-20 K), chemistry of protostellar envelopes to that in the small-scale, warm (> 100 K), gas close to emerging protostars. This will be done through ACA mosaicing observations of a sample of six known hot corino sources covering low-excitation transitions of fundamental complex organics tracing the cold envelope gas. By comparing the relative abundances and physical conditions in the cold gas to the inventories of the complex organics in the hot corinos, we will address to what degree the natal conditions play a role in setting the organic inventories that may be inherited by emerging planetary systems. | Low-mass star formation, Astrochemistry | ISM and star formation | 2025-11-08T11:14:39.000 |
| 435 | 2016.1.00817.S | 40 | Hot on the Trail of Millimeter Emission from the Coolest Stars | Certain ultracool dwarfs (stars and brown dwarfs with spectral types M7 and later) display surprisingly high levels of magnetic activity. Since recent results imply that magnetism in this regime is much more "planetary" than "stellar" in nature, studies of these objects can shed light on the magnetospheric physics of massive extrasolar planets, which are currently not directly accessible. While ultracool magnetism has primarly been diagnosed at centimeter wavelengths thus far, we have recently used ALMA to achieve the first two detections of millimeter emission from (disk-free) ultracool dwarfs, opening a new window in this field: short synchrotron lifetimes at these wavelengths offer the chance to better understand how these cool objects can accelerate electrons to relativistic speeds. We have identified two additional probable mm emitters and propose to attempt to detect them with ALMA, completing the census of such objects known at this time. Detections will double the number of mm-emitting ultracool dwarfs; upper limits would imply new high-frequency behavior compared to our first two detections. | Main sequence stars, Brown dwarfs | Stars and stellar evolution | 2018-06-27T21:40:00.000 |
| 436 | 2015.1.00466.S | 72 | The mm-Wave Interferometric Survey of Dark Object Masses (WISDOM): Increasing the number of supermassive black hole mass measurements with molecular gas using ALMA | Black holes are considered to play an important role in the galaxy evolution process, leading to various known correlations between the mass of the supermassive black hole (SMBH) and host galaxy properties. The correlations, however, are based on a relatively small number of measurements and a handful of methods with some limitations on sample selection. Our recent work on NGC4526 with CARMA and on NGC1097 with ALMA Cycle 0 has shown the SMBH mass estimation by tracing the rotation of molecular gas disks in the galaxy centre with high angular resolution. This new method expects the number and variety of accurate SMBH masses to increase in the ALMA era. ALMA Cycle 3 enables one to measure SMBH mass in some nearby galaxies by utilizing extended array configuration. We propose to observe 5 galaxies accross the Hubble sequence: NGC0524 (SA0), NGC4501 (SAb), NGC5064 (SAa), NGC6753 (SAb), and NGC6958 (cD), all of which are expected to show the SMBH-driven kinematics at relatively large apparent radius. The data will allow us to weigh SMBHs using molecular gas at various types of galaxies, and to cross check our method for NGC0524, which has its SMBH mass measured with stellar kinematics. | Galactic centres/nuclei | Active galaxies | 2017-02-24T13:48:29.000 |
| 437 | 2015.1.00633.S | 48 | Debris Disk Structure Disentangled | We propose observations of a coherent sample of three edge-on disks that have all been spatially resolved at submm wavelengths and have asymmetric structures observed in scattered light. These disks share two common properties. The first is a well-defined ring of planetesimals, and the second is wings of diffuse dust, which probably come from dynamical interaction either within the disk or between the disk and interstellar medium. Our proposed observations will perform three critical functions: first, unambiguously identify the stable planetesimal belts in three edge-on disks by tracing the location of large (mm-sized) grains out to large radii and determine if these belts are circular or eccentric and therefore perturbed; second, unambiguously determine if non-planetary interaction in the form of interstellar medium ablation is occuring by looking for large grains out of the midplane, and third, measure the grain emission in the same regions as scattered light is observed thereby providing grain albedos. | Debris disks | Disks and planet formation | 2017-09-06T00:00:00.000 |
| 438 | 2017.1.00628.S | 20 | Confirming a Disc Around the Geminga Pulsar | Planets and asteroids can survive post-main-sequence stellar evolution, as around some white dwarfs - however, a massive star that becomes a supernova should destroy any planetary system. It has been proposed that a second generation of planets can form from a circum-neutron star material, but no analogues to cool proto-planetary discs around young stars have been discovered. We now have a candidate signal towards the nearby mid-aged Geminga pulsar, with submillimetre emission characteristic of dust particles, and comprising at least a few Earth masses. This is an unusual system where low speed and local density allow interstellar material to penetrate into the pulsar wind nebula. We propose for ALMA time to image the dust-source geometry, and search for gas inflow, and so test this new pulsar-planet formation hypothesis. [This is a re-submission of approved programme 2016.1.00557.S, as the ALMA configurations are not matched to our goals in the remainder of Cycle 4. Our discovery data have now been submitted for publication, as recommended in the 2016 feedback.] | Disks around low-mass stars | Disks and planet formation | 2019-01-29T11:20:46.000 |
| 439 | 2017.1.01552.S | 33 | Zooming in to massive star birth | Extra uv coverage during an antenna configuration transition in our ALMA Cycle 3 observation of protocluster G286.21+0.17 has given us a glimpse into small substructures of its most massive core (~65Msun). In particular, the core is revealed to be dominated by a likely high-mass multiple system, which is surrounded by some weak condensations. Here we propose to use the most extended configuration to study the substructures in this core to answer fundamental questions associated with massive star formation, such as: What is the multiplicity and protostellar density around massive protostars in this core? Is this consistent with predictions of core accretion or competitive accretion models? Are the kinematic structures of circumstellar disks in a massive binary or multiple system similar to those around equivalent low-mass counterparts? | High-mass star formation | ISM and star formation | 2019-02-27T22:31:22.000 |
| 440 | 2019.2.00234.S | 33 | The remarkable 268 GHz line of water: a new tracer of the inner wind of evolved stars? | We have detected a highly excited water emission line at 268.149 GHz in the v2=2 vibrational state from multiple oxygen-rich evolved stars in the sample of the ATOMIUM Large Program in Cycle 6. The upper energy level of this line is above 6000 K, well above most of the other commonly detected (sub)millimeter H2O transitions. Preliminary images from long-baseline observations of June/July 2019 indicate that the 268 GHz line arises from the inner wind close to the star. Since this line appears to be widespread among the observed targets, it has the potential to probe the physical conditions and kinematics of the densest gas within the dust formation zone of O-rich stars that is not accessible to other tracers at lower energy levels. High-spatial resolution images suggest this line exhibits maser action, but this is difficult to confirm with the low velocity resolution of 1.3 km/s of the main-array data. Hence, we propose to follow up on the discovery of this widespread H2O line with the ACA at a much better velocity resolution (0.14 km/s) to spectrally resolve its line profiles in the strongest sources. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2022-09-21T21:50:57.000 |
| 441 | 2019.1.00661.S | 9 | Detection of [CII] in Serenity-18 | We recently discovered Serenity-18, a z~6 main-sequence star-forming galaxy with a molecular gas mass of M(H2) = 5e9 MSun, as traced by our ALMA observations of CO(6-5). This is the first detection of dense molecular gas from a z~6 main sequence star forming galaxy. Furthermore, a X-SHOOTER/VLT spectrum of a nearby background quasar allowed us to detect a metal poor ([Fe/H] = -3.08, [Si/H] = -2.86) DLA located at a spatial separation of 40 kpc from Serenity-18: this is likely a gas clump/filament which is feeding the galaxy's growth. The galaxy/DLA system we discovered is one of the few direct observational evidences of the assembly of a typical main sequence galaxy at the edge of the reionisation epoch. We therefore propose ALMA observations to detect the [CII] emission line towards Serenity-18. This measurement is necessary to characterise the properties of the ISM and investigate the environment in the proximity of the target. In particular, we will calibrate the [CII]-CO relation in view of future ALMA observations of galaxies at cosmic dawn, providing constraints to theoretical predictions for the dense ISM of primordial galaxies. | Damped Lyman Alpha (DLA) systems | Cosmology | 2022-06-21T08:34:23.000 |
| 442 | 2022.1.00485.S | 25 | Weighing the Elias 2-27 protoplanetary disk: a crucial test for a new mass measurement technique | The gas mass of protoplanetary disks is a key ingredient for our understanding of planet formation. However, measuring gas masses is difficult. The most reliable measurements are either unavailable for the foreseeable future (HD far-IR lines) or limited to the most massive disks (disk self-gravity). The most readily available gas masses come from CO, but disks have been shown to have a two order of magnitude uncertainty in their CO abundance, even after including the effects of (isotope-selective) photodissocation and freeze-out. N2H+, a chemical tracer of CO-poor gas, was recently shown to observationally measure the CO-to-H2 ratio and gas disk mass when combined with CO isotopologue lines. We propose to observe N2H+ 3-2 in Elias 2-27, so far the only disk with a dynamically measured gas mass, to measure its gas mass and CO-to-H2 from N2H+ and archival C18O data. Comparing this gas mass to the fully independent dynamical gas mass of Elias 2-27 will provide a crucial calibration test of the N2H+/C18O gas mass measurement technique. If it passes the test, we will have a robust and wildly applicable method of measuring gas masses for hundreds of nearby planet-forming disks. | Disks around low-mass stars | Disks and planet formation | 2024-02-07T22:13:34.000 |
| 443 | 2018.1.01454.T | 185 | Gamma-ray Burst Physics with ALMA: Direct Implications for the Explosions and Progenitors | Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, and thus serve as unique laboratories for high-energy astrophysics and compact-object formation, as well as premier probes of the high-redshift universe. Observations of GRB "afterglows" provide critical insight into the energy scale and local environment of the bursts, thereby elucidating the explosion mechanism and nature of the progenitors. However, the existing extensive optical/X-ray afterglow data alone are degenerate with respect to these GRB properties. Millimeter and centimeter observations are critical for breaking these degeneracies, but pre-ALMA GRB follow-up has yielded a mm-band detection rate of <5%. We have begun to remedy the dearth of mm-band detections through our Cycle 4 ALMA pilot programs, which were successful in detecting and characterizing mm emission from GRB 161219B. Following on this success, we now propose a mm-band survey comprising ALMA ToO observations of 5 GRBs to begin to address key unsolved questions. We will support these ALMA data with JVLA observations (30 hours), extensive optical follow-up (Gemini, Magellan, MMT, Keck), and X-ray monitoring (Swift, Chandra, XMM). | Gamma Ray Bursts (GRB) | Cosmology | 2021-06-30T00:00:00.000 |
| 444 | 2019.1.00411.S | 188 | Small-Scale Clustering of CO emitters around Quasars at z~4 | Luminous quasars (QSOs) at z~4 are the most strongly clustered population known at this epoch, and should thus reside in massive dark matter halos surrounded by large overdensities of galaxies. In order to quantify overdensities of optical galaxies around QSOs, we recently conducted a survey for Lyman alpha emitters (LAEs) in the environs of 17 QSOs at z~4 and measured the QSO-LAE cross-correlation function. We detected an LAE overdensity of 1.4 in QSO fields and found that LAEs are significantly clustered around the QSO. However, our measurements fall short of the predicted overdensities by a factor of 2.1. This discrepancy could be explained by the presence of excess dust in galaxies near QSOs, which make them invisible in the optical. Here we propose to use ALMA to explore this possibility and quantify the overdensities of CO(4-3) emitters in the environments of our 17 QSOs, by measuring the QSO-CO emitter cross-correlation function at small (< 1 Mpc) scales. The proposed dataset represents the final piece to clearly characterize high-z QSO environments, ultimately allowing us to trace simultaneously the clustering of both optical and dusty galaxy populations around QSOs. | Lyman Alpha Emitters/Blobs (LAE/LAB), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2021-01-30T19:31:34.000 |
| 445 | 2015.1.00664.S | 39 | Physical mechanisms of bulge formation in galaxies at z=2 | Massive quiescent galaxies are extremely compact at z=2 while the majority of star-forming galaxies have more extended stellar disks. Theoretically, ~40% of massive star-forming galaxies are expected to form a dense compact core through dissipative processes such as violent disk instabilities or mergers (wet compaction). We propose 1.1 mm observations of 20 massive log(M*)>10.6 rotation-dominated star-forming galaxies at z = 2.0-2.6, whose kinematic properties (including the spin parameter) and stellar structure are well-characterized by the KMOS3D/CANDELS/3D-HST surveys. High (0.2arcsec) and low (1.5arcsec) spatial resolution 1.1 mm mapping will allow us to characterize the true spatial distribution of the star formation activity and identify unambiguously the presence of compact (Re~1 kpc) starbursts in the galaxy centers. By investigating whether the star-forming targets with low spin parameter more likely exhibit a central starburst compared to the mass- and star formation-matched control sample with high spin parameter, we will directly test the hypothesis that wet compaction plays a crucial role in bulge formation at the peak epoch of galaxy formation. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2017-10-20T07:52:09.000 |
| 446 | 2012.1.00647.S | 6 | Probing Formation of Keplerian Disks around Protostars | We propose to use ALMA to directly image Keplerian disks forming around protostars in their innermost envelopes. Keplerian disks have been found around pre-main-sequence stars and have been intensively studied because they are most probable sites of planet formation. According to the classical picture of star formation, Keplerian disks are naturally formed as a by-product of star formation. There has been, however, no firm detection of Keplerian disks around protostars up to date, mainly because it was difficult for us to clearly distinguish Kepler motions from other motions such as rotation having a constant angular momentum. We have been using the submillimeter array (SMA) to study the disk formation around protostars. Together with our newly implemented approach to analyze rotation motions in envelopes around protostars., we find that rotation-law of infalling envelopes around protostars may change at the innermost envelopes, which may suggest Keplerian disk formation there. However, the sensitivity of the SMA was not high enough to directly image disks forming around these protostars. We will take advantage of unprecedented sensitivity of ALMA, which is extremely better than SMA and other mm-interferometer, to directly image Keplerian disks forming around protostars. Observational results will be also carefully compared with theoretical calculations of the disk formation around protostars to understand the details of the disk formation mechanism. A similar proposal submitted in the Cycle 0 was approved, although the observations have not been executed yet. In this proposal, we update the targets based on our latest SMA observations, and plan observations at even higher angular resolution and sensitivity as compared with the observations in Cycle 0.In addition to this proposal, another ALMA Cycle 1 proposal to study the disk formation and evolution around more evolved protostars is submitted by Yen et al. These two proposals are complementary to each other. | Low-mass star formation | ISM and star formation | 2015-10-21T18:02:09.000 |
| 447 | 2015.A.00026.S | 2 | On or Off? Resolving the surprising submm emission from a record-breaking "quiescent" galaxy at z=3.717 | How and when galaxies stop forming stars remains a key unresolved question in astronomy. Quiescent galaxies in the early Universe, observed shortly after quenching, can provide valuable clues as to which mechanisms are involved but are notoriously hard to identify securely. Using Keck/MOSFIRE, we have detected Balmer absorption lines in the stellar continuum spectrum of a z=3.717 galaxy, implying it must have formed its 10^11 Msun of stars in ~300 Myr at z~5-6 before quenching abruptly, only 0.5 Gyr before being observed. Surprisingly, ALMA also detects strong 870um continuum emission toward this galaxy, suggesting it may still be forming stars at ~200 Msun/yr! To settle this puzzling contradiction, we propose a short program to observe the [CII] line in Band 8 to determine if the sub-mm emission is physically associated with the quiescent galaxy: if so, this system would provide an unprecedented view of the link between SMGs and their quiescent descendents; if not, this would confirm this galaxy as the most distant quenched object known to date. Owing to the record-breaking distance of this old galaxy, ALMA is by far the most efficient tool to answer this question. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2017-08-16T09:08:45.000 |
| 448 | 2016.1.00104.S | 64 | Double-ring debris disks at 10s of au: probing how far out planets can form | The census of exoplanets only shows a few with 10s of AUseparations. On the other hand, observations of debris disks have shown that planetesimals can form at large separations, but it is not yet clear how far planets can form. Debris disks provide a unique tool as they can reveal the presence of planets at tens of AU. HD92945 and HD107146 are uniquely placed to pursue this question because they have broad disks with double rings at 10s of AU that suggest the presence of planets at large separation. However, 3 different scenarios can explain this and differ in where the planets formed: 1) a planet formed in situ opens a gap in a broad disk by direct scattering and resonance overlap; 2) a planet that formed closer in and migrated outwards traps planetesimals in resonances; 3) an eccentric planet formed closer in, but was scattered out then opens a gap through secular interactions with the disk. These scenarios predict significant differences in the disks' high resolution structure that are detectable by ALMA. We propose to observe these systems at a resolution of 0.6" to disentangle the origin of the double rings and planet formation history at large separations in these systems. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2018-04-16T00:00:00.000 |
| 449 | 2021.1.01487.S | 112 | What are the best conditions for shielded debris disks? | Many main-sequence stars are surrounded by debris disks, similar to the asteroid/Kuiper belts in our Solar System. A recent discovery is that massive debris disks may harbor a substantial amount of CO gas, a novel aspect in disk evolution. Half of the gaseous debris disks contain an unexpectedly high amount of CO, requiring an efficient shielding from the UV field. So far shielded CO disks were mainly found around young A1-A7-type stars at relatively large stellocentric radii. Here we propose a systematic exploration of the parameter space, by searching for CO in dust-rich debris disks around F1-A8 and A0-type stars, and also observing systems with more compact disks. Using our proposed ALMA Band 6 observations of a carefully compiled target list (including new debris disk discoveries) we will search for CO, characterize the geometry and mass of the gas disk, and look for correlation with environment parameters. Our project will determine for the first time the physical conditions where shielded debris disks could exist, and use a population synthesis model of the results to outline the evolution of gaseous debris disks. | Debris disks | Disks and planet formation | 2023-09-01T09:40:00.000 |
| 450 | 2015.1.01108.S | 24 | A molecular disk wind from DG Tau B ? | We propose a sensitive band 6 study at 0.2$'' resolution in 12CO(2-1) of the remarkable conical molecular flow originating from the low luminosity Class I source DG Tau B. Consistent transverse velocity asymetries have been recently detected across the flow with the SMA. DG Tau B is currently the closest at d=140 pc and most convinving case for flow rotation. The inferred rotation velocities of 1 km/s pose theoretical challenges to the three most likely models for the origin of the CO rotation flow flow (swept-up gas from the parent rotating core, photo-evaporated or centrifugal MHD disk wind) but each of these scenarii The proposed ALMA observations will reveal the innermost morphology and dynamics of the outflow on scales allowing to directly probe the connection with the accretion disk. These observations will allow to definitely test the rotation interpretation, put stringent constraints on the launching point of the flow and investigate angular momemtum distribution in the early stages of star formation. | Outflows, jets and ionized winds | ISM and star formation | 2017-07-29T12:13:04.000 |
| 451 | 2022.1.01790.S | 0 | Exploration of the innermost region of the nearest Narrow line Seyfert 1 galaxy 1H 0323+342 | The discovery of gamma-ray emission by the Fermi satellite from radio-loud Seyfert 1 galaxies (NLSy1s) has attracted a great deal of interest among the highly-energy astrophysical community. This suggests the emergence of a new class of AGN with relativistic jets. In recent studies, NLSy1s have been considered candidates for galaxies with super-Eddington accretion flows. Theoretical studies of super-Eddington accretion flows suggest that the nearby BH is filled with dense gas. However, observational verification of central cores of NLSy1s, a candidate of AGN with super-Eddington accretion flows, has not yet progressed. Revealing the nature of the central core of NLSy1s will not only allow comparison with theoretical suggestions but will also lead to a unified understanding of AGN in comparison with other AGN with different accretion disks. This proposal will examine the Faraday Rotation Measure of NLSy1s 1H 0323+342 in Band 6, which directly traces electron density and magnetic field. 1H 0323+342 is known as the nearest NLSy1s (z =0.063) and is one of few NLSy1s where the host galaxy is spatially resolved and the best target that allows us to probe the innermost region of the jet. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-03-18T15:33:54.000 |
| 452 | 2017.1.00098.S | 13 | The Dust Disk in the O-Type Protostar G17.64+0.16 | At the very highest resolution available to ALMA (20mas) we will image the continuum emission to find the elongated structure representing the dust disk around G17.64+0.16. We imaged this O-star along with 5 others (>10^5Lo) in Cycle 2. The plethora of complementary observations, including multi-baselines IR interferometry indicate a disk around the central 20Mo O-star with radius >80au, while our Cycle 2 data constrain the radius to <150au. It powers a wide angle outflow and has a weak, but molecule rich, line spectrum. In recent protostellar models, G17 is in a late phase, contracting from a swollen configuration with lower surface temperatures that held off the HII ionising phase and facilitated the powering of magnetically collimated jets to a main-sequence configuration with a radiative stellar envelope now driving the wide angle wind, destroying the surroundings and beginning to ionise the disk surface. Only one other source has being caught in this relatively shorted lived transition phase. G17 is therefore a second important piece in this picture of massive star formation. To support this picture it must have formed from a disk, with ALMA at 20mas we will now confirm this. | Disks around high-mass stars | Disks and planet formation | 2019-02-22T03:43:05.000 |
| 453 | 2018.1.00543.S | 18 | Simultaneous AGN and star formation driven feedback in action on a massive, typical galaxy at z~2 | Powerful outflows driven by AGN and star formation activity play a key role in transforming star-forming galaxies above the Schechter mass into passive systems. Understanding this process is essential at z~2, when the cosmic star formation density and frequency of outflow activity in galaxies peaked. Yet, our knowledge of feedback in typical, massive star-forming galaxies at z~2 is incomplete given the little knowledge we have of molecular outflows. To improve upon this situation we propose to study the molecular outflow in GS30274, a typical massive galaxy at z~2. Our high resolution Ha data reveal that this galaxy has two distinct modes of outflow acting simultaneously: (1) a nuclear AGN-driven outflow, and (2) an extended outflow most likely powered by massive star forming clumps. Our proposed ALMA observations represent a unique opportunity to simultaneously investigate, on the same spatial scales, the characteristics of both ionized and molecular phases of outflows driven by AGN and star forming activity. These observations will provide a direct test of feedback-driven quenching in normal, massive galaxies in the component that carries most of the mass - the molecular gas. | Galaxy structure & evolution | Galaxy evolution | 2021-01-04T23:52:51.000 |
| 454 | 2015.1.00591.S | 138 | Molecular Gas Structures in Elliptical Galaxies | We propose CO(1-0) mapping observations of 7 nearby elliptical galaxies. The galaxies were selected for their proximity, and for evidence of the presence of molecular gas in their central regions. With spatial resolutions of ~0.5-1", we will be able to resolve local structures within the molecular gas at scales comparable to those of large galactic giant molecular clouds. Furthermore, we intend to carry out a detailed study of the local and large scale dynamics of any molecular gas present in these objects. The data obtained in these observations will be used to study in unprecedented detail the mechanisms of star formation/inhibition in elliptical galaxies, origin of the molecular gas in these objects, and try to detect organized local molecular structures in them (GMCs, spiral arms, wisps, etc). These properties will be compared with those of lenticulars and spirals in the literature. ALMA Cycle 3 is ideally suited for these observations, providing both the required sensitivity and high-quality imaging for this project. | Early-type galaxies | Galaxy evolution | 2017-12-15T00:00:00.000 |
| 455 | 2016.1.00156.S | 1 | Wave Heating in Solar Prominences | The mechanism responsible for heating the solar corona is one of the most fundamental problems in solar physics and astrophysics in general. Recent observations by the Hinode and IRIS satellites have revealed that the solar atmosphere is filled with small-scale oscillations caused by waves that can carry sufficient energy to heat the corona. However, it is unclear whether waves actually contribute to coronal heating, because of the difficulty in measuring the temperatures of chromospheric features in the corona. ALMA is the first instrument that can directly measure the temperature of the highly-resolved chromosphere. We propose observations of prominences above the solar limb for several hours jointly with ALMA and IRIS. By comparing a temperature map by ALMA with the spatial distribution of waves along fine structures of prominences observed by IRIS, we can directly investigate the temperature variation associated with the presence of waves. The relationship between temperature changes and wave properties will provide critical information about the mechanism of wave dissipation and thus tightly constrain wave-heating models. | The Sun | Sun | 2018-07-11T06:35:36.000 |
| 456 | 2017.1.00991.V | 0 | Imaging a unique massive binary BH candidate in OJ287 with the EHT+ALMA | We propose 1 mm EHT+ALMA observations of the BL Lac object OJ287, one of the best candidates for hosting a binary SMBH and to study jet formation in magnetically dominated AGN. The improvement in the north-south resolution and sensitivity provided by ALMA and the comparison with quasi-simultaneous, resolution-matched 3 mm GMVA+ALMA and 1.3 cm space-VLBI RadioAstron images will allow us to perform Faraday rotation synthesis and opacity analysis approaching linear scales of 26 Rs. Comparison with a similar campaign performed in spring 2017 will allow us, for the first time, to study the time evolution of the innermost jet structure, magnetic field strength and 3D structure, accretion flow, and non-thermal particle population at scales not probed before in an AGN jet. This information will be used to test jet formation models and the uniqueness of the binary SMBH interpretation by comparing to general relativistic magnetohydrodynamic simulations of tilted accretion disks that might provide a competing model to OJ287. The proposed EHT+ALMA observations promise for the first time to directly reveal the nature of such elusive binary systems. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-02-27T16:44:02.000 |
| 457 | 2015.1.00220.S | 11 | Ubiquitous nuclear molecular outflows in massive z~2 star-forming galaxies? | This proposal aims to investigate the role of nuclear driven outflows in quenching star formation above the Schechter mass (log M*>10.9) by detecting high velocity molecular outflows in some of the same massive SFGs that exhibit prominent nuclear ionized outflows. The first goal is to spatially resolve a molecular outflow we recently discovered with ALMA in the massive star forming galaxy (SFG) zC400528 at z=2.39 (Cycle 2, 2013.1.0092S: P.I. Genzel), to compare the extent of the molecular outflow with that of the ionized H-alpha outflow at comparable spatial resolutions, and to determine the molecular outflow velocities and outflow and momentum rates. We also request time to search for nuclear molecular outflows at lower spatial resolution in 2 additional sources - those with the strongest H-alpha nuclear broad components from our IFU surveys with the ESO VLT. These ALMA Band 3 CO 3-2 observations will provide direct evidence of feedback-driven quenching in normal, massive main-sequence galaxies in the component that carries most of the mass - the cold molecular gas. | Galaxy structure & evolution | Galaxy evolution | 2018-02-17T17:07:07.000 |
| 458 | 2019.1.00946.S | 60 | A Pilot Survey Towards the First Direct Black Hole Mass Measurements at z~5 | Currently, all measurements of supermassive black hole (SMBH) masses at high redshift are based on indirect scaling relation using broad emission line spectroscopy of luminous quasars. The combination of high spatial resolution and superb sensitivity of ALMA makes it possible to directly resolve the gas kinematics within the spheres of influence of the most massive BHs at cosmological distances. The brightest ISM line in galaxies at high redshift is [CII], feasible with ALMA at z>4. In this ALMA program, we propose to carry out a short-exposure snapshot survey of [CII] emissions in nine ultraluminous quasars at z=4.5-5.4, all with minimal BH mass >5x10^9 M_sun and the expected gravitational radius of 0.04"-0.3". We will image these systems at 0.3" resolution to map the galactic scale gas kinematics and to identify objects with strong and narrow nuclear [CII] emission. We will select objects most suitable for future high resolution ALMA observations to fully resolve the BH sphere of influence which would result in the first direct gas dynamics measurements of SBMH masses in the early universe. These data will also be used to study BH feedback in the most luminous early quasars. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-01-16T16:18:24.000 |
| 459 | 2013.1.00162.S | 1 | Confusion-free Mapping of the Node within the Cosmic Web at z=3.1 | We propose mosaicing observations of 1.1mm continuum emission with ALMA band 6. The target region is the central 2'x3' core of the SSA22 protocluster at z=3.1. We select this area since it seems to be the densest region at z=3 and a site where assembly of galaxies and massive black holes is accelerated. The reason is as follows: (i) the "node" of the three-dimensional filamentary structure traced by Lya emitters (LAEs) at z=3.06-3.12. (ii) the existence of several SMGs, QSO, and LABs at z=3.09 Furthermore, the 2'x 3' region contains significant overdensities (2x to more than 12x) of active and star-forming galaxies such as Lyman break galaxies (LBGs) and distant red galaxies (DRGs). We have two main goals: (1) to reveal obscured star-formation and clarify the environmental dependence on galaxy formation, via number counts and the census of 1-mm properties (far-IR luminosity, SFR and SSFR) of major galaxy populations. (2) to resolve the close environment around the SMGs and probe the smaller(>=100 kpc) cosmic web traced out by dusty star-forming galaxies. The proposed study will allow us to explore how environment did affect the formation and evolution of galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2016-09-18T00:00:00.000 |
| 460 | 2021.1.01041.S | 80 | High-resolution radio continuum observations of the knots in W50 - A PeVatron accelerator driven by SS 433's jets | Our proposed ALMA observations will provide the highest-resolution radio continuum view of the innermost X-ray knots in the eastern and western jets powered by the Galactic microquasar SS 433 and recently identified by HAWC as a Galactic PeVatron accelerator. ALMA will, for the first time, resolve and characterize properties of the knots likely associated with termination of the inner jet. Our primary goals are: (1) detect and confirm the existence of the knots in the radio band, (2) determine the spectral index to probe the acceleration mechanism, and (3) conduct morphological studies, including measurements of the angular size of the knots, compared with the X-ray features. This investigation, uniquely suited for ALMA, will allow testing theoretical models and advance understanding of the particle acceleration and knot formation processes. | Black holes | Stars and stellar evolution | 2023-04-28T08:01:40.000 |
| 461 | 2017.1.01077.S | 138 | Bulge Asymmetries and Dynamical Evolution (BAaDE) III | A radio survey of red giant SiO sources in the inner Galaxy and Bulge is not hindered by extinction. Extremely accurate stellar velocities (<1 km/s) and positions are obtained with minimal observing time (<1 min) per source. Our aim to detect over 20,000 SiO maser sources yields data comparable to optical surveys with the additional strength of a much more thorough coverage of the highly obscured inner Galaxy. The large sample can reveal dynamical structures, minority populations and their velocity structure to be compared with kinematic structures seen in molecular gas, complex orbit structure in the bar, or stellar streams resulting from recently infallen systems. Modeling of the bar and bulge dynamics will be done using this new kinematic information in the inner Galaxy region. Our survey yields bright SiO masers suitable for follow-up Galactic orbit and parallax determination using VLBI. We observed 19,000 sources with the VLA at 43 GHz (0 | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-03-01T03:32:31.000 |
| 462 | 2015.1.01308.S | 10 | From Dark to Light: Star Clusters in Formation | We propose to study the disk and envelope properties of YSOs in the dense star forming environments of Serpens Main and Serpens South -two young clusters, one with an age of 100,000-200,000 years and the other around 2 million years. We will survey 51 known and suspected YSOs in Serpens Main and 44 in Serpens South with 0.6" resolution in the continuum at 220 GHZ and the DCO+ J=3-2 line. We have chosen a combination of resolution and spatial frequency coverage which will allow us to measure the disk mass (inside 250 AU) and envelope mass (inside 4000 AU) in these sources. Even with 2 minute integrations per source, we can improve on previous studies of these regions by nearly a factor of 100 in mass sensitivity and a factor of 9 in resolution. The results will reveal how much circumstellar mass and its distribution varies with age and YSO luminosity. The requested observations are deep enough that we hope to detect circumstellar mass associated with significantly sub-solar luminosity objects, allowing identifications of new YSOs in the cluster. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-10-09T05:55:06.000 |
| 463 | 2019.1.01634.L | 974 | REBELS: An ALMA Large Program to Discover the Most Luminous [CII]+[OIII] Galaxies in the Reionization Epoch | REBELS will construct the first large statistical samples of high-luminosity [CII]+[OIII]-emitting galaxies in the reionization epoch. REBELS will identify these bright galaxies by systematically targeting the 40 UV-brightest galaxies found over 7 deg^2 and pursuing spectral scans (using band-6/5 [CII] searches at z<8.5 and band-7 [OIII] searches at z>8.5 for maximal efficiency). Already, on the basis of our 1+11-hour pilot programs, five of the seven most luminous [CII]-emitting galaxies known at z~7 have been identified. From the ~25-30 high-luminosity [CII]+[OIII]-emitting galaxies discovered with REBELS (from z~9.5 to 6.5), we will (1) map out the bright end of the z>6.5 [CII]+IR luminosity functions and their evolution, (2) break the high-z spectroscopic redshift record for line-emitters, and (3) create statistical samples of high-mass galaxies needed to characterize dust and stellar mass growth in the early universe while gaining a view of their kinematic structure. Compellingly, REBELS will provide the community with the bright, [CII]+[OIII]-emitting galaxies urgently required for efficient scientific discovery at z>6 with ALMA and JWST. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2021-06-05T00:00:00.000 |
| 464 | 2017.1.01260.S | 129 | Revealing the missing link between normal and starburst galaxies at z~0.15 -- a follow-up to SEPIA detected galaxies | We propose to measure the intensity of the CO(2-1) lines on 11 H-ATLAS galaxies (z~0.1, 5 merging system and 6 isolated galaxies) by ALMA band-5 to probe the kinemetry and the star formation efficiency of the local starburst galaxies, which are located above the star-forming main sequence (sSFR > 5 main sequence sSFR). The requested 0.7'' spatial resolution will allow us to (1) directly identify the merger components and merger stage in the 5 merger systems and characterize the CO Tully-Fisher relation in the 6 isolated galaxies; (2) directly explore the compactness of the gas distribution and CO-to-optical radius ratio with different star formation mode. Our previous ALMA observations in cycles 1, 2, 3 have targetted a sample of 67 star-forming main sequence galaxies at the same epoch. The targets we are proposing will yield a star formation complete sample at redshift 0.1, permitting us to study the whole picture of the star formation efficiency across a wide range of IR luminosity. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2019-09-04T05:11:31.000 |
| 465 | 2018.1.00684.S | 17 | Measuring Velocity Structure of MHD Wind from a Protoplanetary Disk with High Mass Accretion Rate | We propose to observe line transitions of CN and 13CO with high velocity resolution and high sensitivity to measure velocity structure of the MHD wind from a protoplanetary disk, making use of the PDR species (CN) line as a disk wind tracer and the 13CO line as a tracer of Keplerian rotation. The target object, the RU Lup disk, is almost face-on and active with a mass accretion rate of ~1e-7 M_sun/yr, an order of magnitude larger than that of the TW Hya disk from which we couldn't find a significant signature of disk wind in our previous observations. Recent MHD simulations suggest that angular momentum transfer and mass accretion in the disk surface will be induced by magnetized disk wind. The new global MHD simulations together with the detailed chemical model and radiative transfer calculations show that the difference in the maps of intensity weighted velocity dispersion between the CN and 13CO lines will give us clear evidence of the disk wind from the active disk. Our observations of radial wind velocity profile will be useful to reveal the wind mass loss rate, which is essential to understand gas dispersal from the disk and then planet formation processes. | Disks around low-mass stars | Disks and planet formation | 2020-07-26T09:59:47.000 |
| 466 | 2017.1.00301.S | 158 | Measuring black hole masses in early-type galaxies with ALMA | Molecular gas dynamics can potentially provide the most precise determinations of the masses of black holes in the centers of early-type galaxies (ETGs), for those ETGs that host circumnuclear disks of cold gas in regular circular rotation. In Cycles 2/3 we began a program to map the gas kinematics in nearby ETGs hosting central dust disks, observing CO(2-1) with angular resolution comparable to the black hole radius of influence. The majority of these targets exhibit regular gas rotation on subarcsecond scales suitable for dynamical modeling. For Cycle 5, we propose to complete our survey of the nearest and best targets accessible to ALMA having estimated black hole radii of influence >=0.15 arcsec. Using the new ALMA data, we will carry out dynamical modeling to determine black hole masses. In cases where high-velocity rotation is detected from gas within the black hole sphere of influence, we will propose higher-resolution observations in a future cycle to map the central gas kinematics in detail, providing high-precision measurements of black hole mass with minimal susceptibility to systematic errors, as demonstrated with our Cycle 3 observations of NGC 1332. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2019-03-06T18:13:38.000 |
| 467 | 2021.1.00273.S | 45 | AGB spiral-shell patterns in post-AGB sources | Theoretical models predict that circumstellar spiral/shell patterns of asymptotic giant branch (AGB) envelopes can be formed in binary systems. Recent interferometric observations have shown that these patterns reveal key parameters of the binary properties and mass-loss histories. It is now timely to investigate such patterns remaining in the outer parts of young post-AGB sources with BOTH spiral-shells and bipolar lobes, which are essential for understanding the shape transition from AGB to planetary nebula (PN) phases. We propose to use ALMA to obtain CO J=2-1 mosaics of two iconic objects: CRL 2688 (pre-PN) and NGC 7027 (PN) with high sensitivity and resolution. Molecular line observation will provide velocity information, not present in scattered light images, thus help in reconstructing the patterns. Our goal is to resolve the shell-like patterns in the extended halos around these post-AGB objects, in order to 1) characterize the orbital parameters of the central binary from the properties of recurrent patterns, 2) investigate the origin of the coexistence of geometrically distinct structures, and 3) study the fast-slow wind interaction. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2023-04-18T12:09:42.000 |
| 468 | 2017.1.00270.S | 46 | Dust vs. CO: Do both trace molecular gas emission in high-redshift galaxies? | The molecular gas content and distribution is arguably one of the most fundamental properties of any galaxy, in particular with respect to its stellar mass and star formation. The community currently mainly uses two approaches to derive molecular gas properties in high-z galaxies: through measuring (1) the CO luminosity and (2) the dust continuum emission. However, in the few cases where both sets of observations exist, the current low-resolution imaging indicates that the dust continuum has substantially smaller scale lengths compared to low-J CO emission. If that was a general property of high redshift galaxies, this would have far-reaching consequences for determining molecular gas masses and morphologies from centrally concentrated dust emission. Using early results from the ASPECS large program, we propose matched-resolution (0.5") imaging of well-characterized CO/dust-detected main sequence galaxies in the UDF to measure the dust/CO/optical scale-lengths at a resolution of a few kpc. We will thus assess whether both methodologies (dust vs. CO) can be used interchangeably to quantify the molecular gas distribution in high-z main sequence galaxies. | Galaxy structure & evolution | Galaxy evolution | 2019-02-23T21:46:49.000 |
| 469 | 2016.1.00534.S | 11 | Molecular gas excitation in z=0.7 main sequence galaxies | CO observations of main-sequence (MS) galaxies at high-z have shown that their star formation efficiency is lower than in case of merger driven SMGs, more consistent with the star formation efficiency in local spiral galaxies. The picture that emerges is that SMGs form stars more rapidly because their gas clouds are more compressed so they churn more quickly through their gas reservoirs than MS galaxies. This difference in the physical conditions of the gas can be traced using the CO and CI line ratios. In cycle 3 we have been granted observing time to probe the gas excitation in three z=0.7 MS galaxies. Our data shows that the excitation in these galaxies is even lower than expected from studies of MS galaxies at z=1.5-2.5. In addition our data reveal lower dust emission than expected from standard gas to dust mass scaling relations which suggests that metallicity effects may become important. So far our approved CO76/CI21 line and rest-frame 350 micron continuum observations from cycle 3 have not been observed. We here re-apply for these critical observations to consolidate the low dust emission and to complete the observation of CO and CI in our z=0.7 sample. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2018-03-15T10:51:41.000 |
| 470 | 2017.1.00509.S | 18 | Origin of the Doubly-Flared Disk Structure around the Class 0 Protostar L1527 | In our recent high-angular resolution (~0.2") observation at 0.87 mm using ALMA, we have found a very interesting feature of the infant disk around the Class 0 solar-type protostar L1527. We have resolved the vertical structure of the edge-on disk, and have revealed its 'doubly flared' structure. A radial dependence of the disk thickness is found to have an inflection point at 70 au. Possible origins of this structure are threefold: 1) Stractual and temperature changes in at the disk edge due to the materials accreting from the envelope. 2) A change in dust sizes due to coagulation (grain growth) in the dense and cold mid-plane. 3) A sudden increase of the dust opacity at 0.87 mm expected at the disk edge. In order to disentangle these possibilities, we here propose a very sensitive continuum observation at 3 mm band. With this program, we will be able to make a substantial step toward understandings of disk formation as well as dust evolution in an infant disk around the Class 0 protostar. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-01-04T23:10:33.000 |
| 471 | 2018.1.00113.S | 46 | Molecular tori in Seyfert galaxies | Unified theories of AGN assume that a molecular torus of a few pc-size obscures the BLR around the SMBH in Type 2 nuclei. ALMA detected a 10pc-diameter torus of ~10^5Msun in the Seyfert 2 galaxy NGC1068 using observations of the 6-5 line of CO (García-Burillo+16). New observations have revealed a stratified layered structure of the molecular torus, which extends over spatial scales ~30pc in the low(er) density tracers (2-1 and 3-2 lines of CO). The kinematics of the torus are distorted by strong non-circular motions. A key question is whether these perturbed and surprisingly 'big' tori are the norm in Seyferts and if their properties may change as a function of the AGN luminosity, the degree of obscuration and the Eddington ratio. We propose to map the CO(3-2) and HCO+(4-3) lines and their underlying continuum with a resolution of 0.1"(~7-13pc) in the circumnuclear disks of 10 Seyferts selected from a ultra-hard X-ray sample. With these observations we will detect and isolate molecular tori and have a sharp image of their connection to the hosts. This sample expands the range of AGN luminosities and Eddington ratios covered by other ALMA surveys of Seyferts like NUGA. | Active Galactic Nuclei (AGN)/Quasars (QSO), Spiral galaxies | Active galaxies | 2020-08-06T06:33:41.000 |
| 472 | 2017.1.01727.S | 14 | Exploring the molecular gas in the host of one of the nearest tidal disruption events | PGC 043234 is a post-starburst galaxy which recently hosted ASASSN-14li, one of the nearest and best studied tidal disruption event (TDE). PGC 043234 seems to be the remnant of a merger and has a negligible star formation, as expected for galaxies in this class. Here we propose to observe CO 1-0 to investigate its molecular gas distribution and compare it with other post starburst galaxies which have not hosted TDEs in the past. Our final aim is to gain an insight into the conditins favouring TDEs. | Outflows, jets, feedback, Early-type galaxies | Active galaxies | 2019-04-02T15:40:01.000 |
| 473 | 2015.1.00054.S | 49 | Measuring the superwind radius of OH26.5+0.6 : a recent dramatic increase in the mass loss | Toward the end of the AGB phase, the mass-loss rate dramatically increases. This short-lived stage of intense mass loss (the so-called superwind) represents a crucial phase of stellar evolution but unfortunately remains poorly understood. The extreme OH/IR star OH26.5+0.6, the prototype object for intermediate-mass stars at the tip of the AGB, shows a bright compact, IR envelope ~ 0.4", but a faint extended CO J=1-0 envelope. This is interpreted as the star has increased its mass-loss rate by a factor of ~ 100 (a superwind) in the recent past. ALMA offers for the first time the great opportunity of resolving the superwind in AGB stars. We propose to observe the star using the CO 3-2 where most of the radiation originates in the superwind. We will also study the isotopic ratios of 16O/17O/18O and 12C/13C as a function of radius in order to establish when the star underwent hot-bottom burning. From these observations, we will be able to pin down the time scale of the onset of the superwind, as well as the change in the nucleosynthesis of the two winds. This will advance our understanding of the last stages of stellar evolution of intermediate-mass stars. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-01-12T11:20:08.000 |
| 474 | 2024.1.00555.S | 0 | Galaxy over/under-densities around IGM transmission at z=5.7: a robust constraint on reionization | The timing of reionization holds crucial implications for the formation and evolution of the earliest galaxies. Recent observations based on quasar spectra have challenged the conventional understanding that reionization concludes by z>=6. One of the remaining challenges in this model, however, is understanding the observed large-scale scatter in IGM Lya opacity at z<6. Ongoing reionization in the forms of remaining neutral hydrogen islands and/or fluctuations in the ionizing UV background below z=6 would naturally explain this scatter; however, the anti-correlation between IGM opacity and density predicted by these models is not observed. Specifically, the most transmissive lines of sight have been found to be underdense in Lya-emitting galaxies (LAEs), contrary to expectations. To address this tension, we propose to search for [CII] 158micron emitters in the most transmissive regions of the IGM at z=5.7. We aim to determine whether cosmic underdensities traced by LAEs surrounding extreme transmissive sightlines are real or a selection effect related to Lya emission. If confirmed, the results would have important implications for our understanding of how reionization ends. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy groups and clusters | Active galaxies | 3000-01-01T00:00:00.000 |
| 475 | 2016.1.00268.S | 59 | Probing Inward Motion of Magnetized Gas in Massive Star Forming Region W51e2/e8: From 0.5 pc to 1500 AU | The formation of stars involves a close interplay between turbulence, magnetic fields and gravity. In essence, how the dynamical collapse of gas from clouds to cores is regulated, and in particular, at which scales the collapse may be magnetically regulated and at which scales gravity takes over, are open questions. To better understand the interplay between magnetic fields and collapse dynamics, we request ALMA observations to probe the inward motions of the magnetized gas from large (0.5 pc) to small (1500 AU) scales in the massive star-forming regions W51e2/e8, where there are several high-mass star-forming cores with well measured B-field morphologies from large to small scales. We aim at establishing a comprehensive picture of the inward motions towards W51 e2/e8 from large to small scales in order to 1) determine the collapse pattern and mass accretion rates from large to small scales, 2) determine if the spatial distribution of infall speed is consistent with free-fall, 3) determine the correlation between B, v and g from cloud to core-scales, and 4) distinguish between the ``turbulent core'' and ``competitive accretion'' models of massive star formation. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-02-13T22:15:45.000 |
| 476 | 2015.1.00497.S | 74 | The ALMA Fornax Cluster Survey (AlFoCS) | We propose to map the molecular reservoirs of a complete sample of dust and atomic gas detected galaxies in the Fornax cluster, the nearest representative of the groups and poor clusters in which most galaxies in the universe reside. Combined with our teams complimentary Herschel/ATCA/MeerKAT data we will construct the first complete census of the cool interstellar medium in this cluster. These ALMA data will allow us to understand the effect environment has on molecular gas, through ram-pressure, strangulation & harassment. We will probe the ISM in cluster dwarf galaxies, shed light on the physical cause of the gas disk truncation and morphological transformation, and provide a local baseline for galaxy scaling relations. This project will also have strong legacy value, as this will be the only cluster with homogenous data across wavebands, mapping its galaxy population (from dwarfs to massive galaxies) in exquisite detail. This will directly lead to a greater understanding of the environmental processes quenching and morphologically transforming galaxies in dense environments. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2017-03-09T13:04:18.000 |
| 477 | 2015.1.00821.S | 24 | Probing the Physics Behind Enhanced Star Formation in the Early Universe | We propose a survey of [CII] 158 micron emission from eight normal star-forming galaxies with spectroscopically confirmed redshifts of z=5.8 to 7.6. This emission line provides a unique tracer of the dynamical mass in these galaxies, which can constrain the total amount of gas present. We will use these observations to answer the question of whether an increase in the typical gas mass fractions with increasing redshift is the dominant physical cause behind an observed increase in the stellar-mass to halo-mass ratio at z > 5. These observations will also have tremendous legacy value, as they will probe the evolution of the ratio between [CII] and far-infrared luminosity to the highest redshifts. Finally, by observing the luminosity of this line at such high redshifts, we will pave the way for the future use of ALMA as a redshift machine, as [CII] represents the best chance for spectroscopic redshifts in the epoch of reionization, where Lyman alpha has become diffifult to observe. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2017-09-07T15:21:33.000 |
| 478 | 2021.1.01159.S | 6 | Witnessing the Assembly of a Massive Rotating Disk Galaxy In the Epoch of Reionization | Understanding the nature of galaxies at the end of cosmic reionization is one of the most important quests of galaxy evolution studies today and our comprehension of the galaxy assembly process during this epoch is scarce. We propose to obtain ultra-sensitive, high-resolution three dimensional [CII] imaging of a typical massive star-forming galaxy at z=6.81, which is likely undergoing gas accretion. Recent sensitive ALMA high-resolution observations of [CII] emission revealed a clear spatially resolved velocity gradient and a Sersic n=1 radial profile, which are clear signatures of a rotating disk. However, the HST rest-frame UV and ALMA [CII] images unveiled faint objects in its environment, hinting that the galaxy is undergoing accretion of nearby satellites. The proposed ALMA observations will allow us to (1) provide a sensitive probe of the morphology of this system, including companions, clumps, infall or outflowing structures, and (2) to characterize the dynamical state of the galaxy though velocity field modeling. This project will epitomize the most detailed study of cold accretion during the Epoch of Reionization. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-06-07T14:26:29.000 |
| 479 | 2018.1.00286.S | 216 | Powering sources and Lya escaping fractions of Lyman alpha Blobs in the SSA22 field | "Lyman alpha blobs" (LABs) are spatially extended Lya nebulae seen at high redshift. The origin of Lya emission is unclear. We have observed 35 LABs in the SSA22 field with JCMT and ALMA, and revealed that 11 out of 18 big LABs are detected at submm wavelengths, but none of the 17 smaller ones. We propose deep ALMA observations towards 24 submm-undetected LABs at band 7. Our science goals are the following. First, it is mandatory to observe the small LABs to find out whether SMGs are common in all LABs and to find out that whether there is a uniform powering source for all LABs or whether the sample is more diverse. Secondly, deep ALMA observations will reveal in some cases that internal powering may not be the only mechanism powering the extended Lyman alpha emission. Thirdly, the escape fractions of Lya photons of the submm-detected LABs are significantly lower than those from the Lyman alpha Emitters in other studies. Thus, it is important to determine the Lya escape fractions of the submm-undetected LABs, the majority of the sample, enabling us to investigate the possible connection between the low Lya escape fractions and the physically extended Lya emission in some LABs. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-04-08T00:00:00.000 |
| 480 | 2012.1.00853.S | 4 | Characterizing the volcanic contribution in Io's atmosphere | Jupiter's moon Io possesses a tenuous SO2-dominated atmosphere that feeds the plasma torus in orbit around Jupiter, hence requiring a continuous replenishment mechanism. While the primary origin of the gas is volcanic, it is unclear whether the bulk atmosphere is directly supplied by the volcanic plumes, or if it is mainly sustained by sublimation of SO2 frosts. The volcanic gas composition itself, that depends on the magma composition and the volcanic conduit conditions, is not known. The purpose of this proposal is to bring new constraints on the contribution of volcanism to Io's atmosphere. A chemical search for expected yet undetected volcanic species such as SiO, KCl, S2O and CO is proposed, with an unprecedented sensitivity, aiming at constraing the ionian volcanic regimes. Maps of the main atmospheric species (SO2, SO and NaCl) will be obtained with the best resolution ever achieved at this wavelength (0.3"), in order to correlate the gas distribution with potential sources (volcanic centers, frost patches), as well as to verify the presence of SO2 in cold, polar regions where sublimation is neglectable. In addition, a map of the wind-field will be obtained by measuring Doppler-shifts on the strongest SO2 lines. This will allow to verify if the wind circulation follows a day-to-night pattern, that would be expected in the case of a sublimation sustained atmosphere, or if the circulation is zonal, as was observed by our team on IRAM observations of much lesser quality. | Solar system - Planetary atmospheres | Solar system | 2016-10-13T20:36:48.000 |
| 481 | 2019.1.01666.S | 44 | Efficiency of Star Formation in a Spectacular Molecular-rich Ram Pressure Stripped Tail | The Norma cluster galaxy ESO137-001 is one of the strongest examples of ongoing ram pressure stripping (RPS). Its spectacular 80 kpc multi-phase, multi-component tail has the richest observational coverage among any known RPS galaxies, including HST, VLT MUSE, Chandra, Spitzer and Herschel imaging. Surprisingly, active star formation (SF) is taking place in the hostile environment of the tail. Following our successful Cycle 3 observations that revealed a rich distribution of molecular gas throughout the tail, we propose to observe at a sub-100 pc resolution four areas over the most interesting regions of the tail where the CO emission has various degrees of correlation with Halpha, X-rays and SF. With CO and dense gas tracers HCN and HCO+, we will identify locations of the densest gas component and study how the harsh environment of the RPS tail affects the dense gas and under what conditions and with what efficiency the stripped molecular clumps may form new stars. | Galaxy groups and clusters, Giant Molecular Clouds (GMC) properties | Cosmology | 2021-07-02T00:23:23.000 |
| 482 | 2018.1.00998.S | 21 | Resolving the molecular gas reservoir in a distant interacting radio galaxy | It is now well established that the evolution of supermassive black holes must be inextricably tied to that of their host galaxies. However, we do not yet fully understand the complex gas accretion mechanisms that drive both galactic and supermassive black hole growth. There is insufficient evidence from direct observation of the accreting gas, at epochs spanning much of the history of the Universe. We are using the Australian SKA Pathfinder and ALMA to determine the kinematics of atomic and molecular gas in radio galaxies out to z = 1. Here, we will use the longest baselines of ALMA to spatially resolve CO(2-1) absorption towards the active galactic nucleus of a distant (z = 0.44) radio galaxy, PKS1740-517, recently triggered through tidal interaction with a companion galaxy. We will determine if the CO(2-1) absorption (previously detected using ALMA) is seen against one or both source components, allowing us to establish a kinematical model for molecular gas in the host galaxy. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2020-10-25T08:29:17.000 |
| 483 | 2018.1.00614.S | 76 | Are Large Grains Trapped in Disk Rings? | Radial and/or azimuthal substructures of dust and gas in disks are frequently seen in ALMA images. Dust particles drift towards higher gas pressure and are trapped in pressure maxima, which can be created at the outer edge of the planet orbit or a dead zone. Recent gas and dust observations in a few bright disks show evidence of particle trapping, but remain ambiguous because of high optical depths of continuum emission at the observed wavelengths. Based on our Cycle 4 Band 6 (1.3 mm) disk survey, we propose 3 mm continuum observations for three disks with optically thin rings at a spatial resolution of 0.1 arcsec. By comparing the emission morphology at two optically thin wavelengths (1.3 mm vs. 3 mm) with similar resolution, we will test if dust trapping is the cause for the observed structures. These observations will also be combined with NIR scattered light data, which traces the distribution of small dust grains, to further constrain the origin of dust traps. Combining multi-wavelength observations is the key to fathom the nature of gap-like structures and would vastly accelerate our understanding of the theory of planet formation and disc-planet interaction. | Disks around low-mass stars | Disks and planet formation | 2020-10-17T00:00:00.000 |
| 484 | 2022.1.01034.S | 20 | Detection of Extragalactic Millimeter-Wavelength Transient Sources with SPT-3G | Experiments designed to survey the cosmic microwave background provide a unique opportunity to study the time-variable sky at millimeter wavelengths. The first results from the SPT-3G transient detection pipeline have yielded two long-duration transient (LDT) events with timescales of 2-3 weeks each and flare amplitudes of 4x and 15x their quiescent fluxes. These transients appear to be associated with WISE galaxies at photometric redshifts of z = 0.37/0.68 and z = 0.97. Current observational evidence would be compatible with low-luminosity jet-dominated AGN flares or tidal disruption events, though the extreme flare variability and lack of radio detection makes them peculiar. In this proposal, we are asking for ALMA Band 3 measurements in order to establish accurate positions for the two LDTs. The increased resolution afforded by ALMA will disambiguate which WISE sources are associated with the SPT-3G transient sources, and lay the groundwork for future followup. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-01-10T18:02:31.000 |
| 485 | 2018.1.01264.S | 42 | How did molecular gas end up tens of kiloparsecs away from a massive, recently-quenched z~0.6 galaxy? | A galaxy from our Cycle 5 ALMA survey of massive z~0.6 post-starburst galaxies shows dramatic extended CO(2-1) emission around a galaxy that likely hosts an active galactic nucleus (AGN). The extended CO emission, which spans up to ~80kpc away from the central galaxy, has an incredibly narrow linewidth and represents >50\% of the total CO luminosity of the system. This emission is particularly curious given that star formation in the primary galaxy shut off ~.5-1 Gyr ago-- plenty of time to photodissociate isolated CO. This emission is difficult to interpret with our current data, but could be the result of AGN-driven outflows or a gas-rich merger. Here we propose deep low-resolution CO(2-1) observations to map large-scale and low surface brightness structures, and determine the gas morphology and total gas content of the galaxy. We also propose CO(4-3) observations to understand the physical state of the molecular gas. These observations will help us explain the enigmatic molecular gas distribution in and around this galaxy, and will provide clues as to the mechanisms that quenched star formation in this massive z~0.6 post-starburst galaxy. | Galaxy structure & evolution | Galaxy evolution | 2020-07-24T22:35:16.000 |
| 486 | 2013.1.00916.S | 2 | Can star formation happen without cold molecular gas? | This proposal is designed to assess the role of the cold molecular gas in the star formation process at very low metallicity. It has been recently suggested that star formation could happen in atomic clouds in quasi-pristine environments. To test this scenario, we need a proper quantification of the molecular gas content of a very low metallicity object. SBS0335-052 is the perfect candidate for such experiment. It is the lowest metallicity dwarf galaxy (1/30 solar) of the southern sky, with active and extremely compact star formation (<0.1'', 30pc) that only ALMA can detect. We propose to observe the CO(2-1) line at 230 GHz in band 6 to detect and locate CO in SBS0335-052. This will allow us to measure the molecular gas mass traced by CO, and, with Herschel PDR lines, assess the amount of CO-dark gas, which is expected high at low metallicities. We will relate those measurements to the super star cluster properties (e.g. star formation rate). This project represents an important and necessary step to very low metallicities to put constraints on the Xco factor and to verify the current predictions from numerical simulations. | Spiral galaxies, Dwarf/metal-poor galaxies | Local Universe | 2016-11-16T03:40:42.000 |
| 487 | 2017.1.00277.S | 60 | WISDOM: supermassive black hole mass measurements for nearby spiral galaxies using molecular gas | Black holes are considered to play an important role in the galaxy evolution process, leading to various known correlations between the mass of the supermassive black hole (SMBH) and host galaxy properties (e.g., M-sigma relation, where sigma is the central velocity dispersion of stars). The correlations, however, are based on a relatively small number of measurements and a handful of methods with some limitations on sample selection. Recent works on dynamical SMBH mass measurements using molecular gas kinematics, including our published works and preliminary results, open a possiblity to increase the number and variety of galaxies with their SMBH masses measured with great accuracy. ALMA Cycle 5 enables one to measure SMBH mass in a number of nearby galaxies by utilizing extended array configuration. We propose to observe 7 spiral galaxies distributing in the M-sigma plane yet to be explored with our method. The data will allow us to weigh SMBHs using molecular gas across the M-sigma relation, and will add some late-type galaxies to balance the currently biased sample. | Galactic centres/nuclei | Active galaxies | 2019-02-03T08:07:04.000 |
| 488 | 2016.2.00033.S | 17 | Millimeter line variability in IRC +10216 with ALMA Compact Array. | The pulsation process is the key to understanding AGB wind launching but is difficult to observe. Recently, line variability was found at mm wavelengths and part of which could be due to the pulsation dynamics in the inner circumstellar envelope. This offers the possibility to trace the elusive dynamical processes with monitoring at mm wavelengths. We performed a systematic single dish monitoring of several millimeter lines toward the archetypal carbon star IRC +10216. Regular line intensity and line shape variations were found. Although we found phase shifts in the line variability pattens, they are not well understood. Our Cycle-4 ACA monitoring project is already running to confirm these mm variability features and a Cycle-5 project has also been proposed to extend the monitoring and upgrade it to a higher cadence of once a month to better investigate their dynamical origin. Hereby we propose to improve the running Cycle-4 project by upgrading it also to a higher monitoring cadence of once a month. This will make up the lost epoch and improve the science output of the entire monitoring project. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-10-09T07:31:37.000 |
| 489 | 2013.1.01391.S | 44 | NGC 6357: A Laboratory for Testing Modes of Star Formation | The majority of our observational knowledge of the star formation process is derived from studies of nearby low-mass regions, yet the majority of the energy and momentum involved in star formation is connected to massive stars. This imbalance in our understanding is a result of the relative inaccessibility of massive star-forming regions to high-spatial resolution observations. Further progress in this area requires investigation into both the substructure of star-forming clouds (at the scales of prestellar cores) and the environmental medium in which these cores form and evolve. We propose to undertake a comprehensive investigation of the dense molecular ISM in the massive star-forming region NGC 6357 with ALMA. We will map three regions in varying environmental conditions in 3.3 mm continuum and the dense gas tracers HCN, HCO+, N2H+, and several of their isotopologues at 0.1 km/s resolution. We will investigate the interconnected structure of the ISM from ~5000 AU scales up to our mosaic size of ~5 pc, model our results to attempt to discriminate between various modes of star formation, and extrapolate to other galaxies. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 490 | 2023.1.00942.S | 0 | The most obscured AGN revealed by the 448 GHz water transition | To explain the Cosmic X-ray Background, an undetected population of deeply obscured AGN (NH >> 1e25 cm-2), missing even in ultra hard-X ray surveys, is invoked. We aim to use the H2O 448GHz transition to reveal these elusive AGN. In deeply dust-obscured AGN, all the accretion disk UV/optical emission is reprocessed by dust into infrared (IR) radiation. The surface luminosity densities (Sigma(L_IR)) easily exceed that of a maximal starburst in these nuclei. Only under these conditions, H2O molecules are efficiently pumped by IR radiation and produce intense H2O 448GHz emission. Despite H2O 448GHz is relatively bright, its potential as buried AGN tracer at high-z is still mostly unexplored, mainly due to the lack of local data. Hence, we propose to observe H2O 448GHz, and simultaneously CO(4-3) and sub-mm continuum, in a representative sample of 16 (11 new+5 archive) local U/LIRGs. U/LIRGs have the most compact and dusty nuclei locally, so they are candidates to host elusive obscured AGN. With these data, we will derive nuclear sizes and Sigma(L_IR) to reveal hidden AGN. We will also calibrate the key H2O 448GHz vs Sigma(L_IR) relation needed to identify buried AGN at high-z. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2025-06-12T16:29:32.000 |
| 491 | 2021.2.00140.S | 338 | What is the origin of rotational motions in dense cores? | Rotation of star-forming dense cores plays essential roles in star and planet formation. Its origin is, however, not fully understood yet. Nevertheless, recent theoretical simulations suggest that a small velocity fluctuation within filamentary clouds could turns out to be rotation in dense cores formed in the filamentary clouds through their self-gravitational fragmentation. In order to follow up this tantalizing suggestion, we propose to carry out ACA+TP observations of 30 pre-stellar dense cores homogeneously selected in the B211/B213 single filamentary cloud of the Taurus star forming region. The 30 pre-stellar cores cover the central density of 10^4-10^6 cm^-3 representing various evolutionary stages, which allows us to investigate how the kinematics within cores evolves. The observations will be made in C18O, N2D+, and SO lines in Band 6 at 7" resolution, which is high enough to spatially resolve each pre-stellar core. The obtained results, which can be directly compared with theoretical simulations, enable us to observationally investigate first time how turbulent motions in filamentary clouds evolve into rotational motions in cores during the core formation and evolution. | Low-mass star formation | ISM and star formation | 2023-12-28T20:15:36.000 |
| 492 | 2023.1.01424.S | 0 | Chemical Diagnostics of Star Formation in the Bar-end of NGC 2903 | How do the dynamics of molecular clouds under the gravitational potential of a galaxy affect star formation? This is a longstanding issue in the star formation study of nearby galaxies. A barred spiral galaxy, which reveals a characteristic gas motion in the bar, is an excellent target to tackle this issue. In the nearby barred galaxy NGC 2903, molecular clouds show weak star formation activities at the bar-ends, which are connection points of the bar and the spiral arms, while some other barred galaxies have active star formation there. The difference can be attributed to gas dynamics or the evolutionary stage of molecular clouds. In order to explore these possibilities, we propose multi-molecular-line observation including shock, PDR, and dense gas tracers with ALMA in the 3 mm band at a resolution of 70 pc. By using chemical compositions of molecular clouds as diagnostics tools, we will assess the environment of molecular clouds such as shock, PDR, and fraction of dense gas. This observation will provide us with an important clue to understanding the effect of gas dynamics and shock on the star formation processes in barred galaxies. | Starbursts, star formation | Active galaxies | 3000-01-01T00:00:00.000 |
| 493 | 2015.1.00001.CAL | 0 | Grid Monitoring Cycle 3 (test) | 3000-01-01T00:00:00.000 | |||
| 494 | 2023.1.00486.S | 0 | 404 Error: Magnetic Fields in Disks Cannot be Found. Line Polarization of Beta Pic May Fix our Broken Links | Magnetic fields are crucial for the accretion of mass from the protostellar disk onto the star, yet they have not been clearly detected in any disk so far. Polarimetric observations and theoretical modeling indicate that it is extremely difficult if not impossible to measure the magnetic field morphology in circumstellar disks via Zeeman or (sub)millimeter continuum polarization observations. One unexplored and promising way to measure the magnetic field morphology in the plane of the sky is via line polarization (the Goldreich-Kylafis (GK) effect), which suggests that line polarization is perpendicular or parallel to the magnetic field direction. However, polarization will not be detected if the lines are thermalized, and lines are thermalized in most circumstellar disks. We propose to observe CO(2-1) line polarization toward the debris disk Beta Pic, which is very bright in CO, and the line is not thermalized. These observations will be the first detection of the magnetic field in the plane of a disk, thus fixing our links between observations and disk magnetic fields. | Debris disks, Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 495 | 2021.1.01588.S | 59 | A snowline origin for the substructures in the Class I disk GY 91? | The omnipresence of gaps and rings in Class II disks indicate that wide-orbit giant planet formation proceeds readily. Planet formation models suggest that the growth of giant planets at tens of au within timescales of a few million years requires high concentrations of dust, prompting the question of whether the substructures observed in Class II disks are preceded by an earlier generation of substructures. Gaps and rings have been discovered in several Class I disks, but it is not yet clear whether they also trace planet-disk interactions or represesent the hypothesized ``first-generation'' substructures. However, the gaps in the Class I disk GY 91 fall close to the expected locations of the CO and N2 snowlines as predicted by radiative transfer modeling. To investigate whether these snowlines may be responsible for forming GY 91's substructures, we propose to use chemical imaging of 13C18O and N2H+ to constrain the locations of the CO and N2 snowlines. Establishing such a connection will provide insight into what processes enable the apparently fast growth timescales of giant protoplanets. | Disks around low-mass stars | Disks and planet formation | 2023-03-15T09:35:11.000 |
| 496 | 2016.2.00195.S | 18 | Direct measurements of pattern speed of bar | We propose CO(1-0) observations of nearby barred spiral galaxies whose bar is aligned in the direction of the major axis of the galaxy. Since molecular gas is expected to flow along the offset ridge in the bar as shown in many simulations, we can measure the pattern speed of the bar directly in these galaxies. Recent studies of the pattern speed of the bar indicate that late-type spirals have slow bar, while early-type spirals have fast bar. It may imply the difference of the degree of the central concetration of dark matter or dynamical age of bar, since theoretical studies predict that bars slow down by the dynamical friction of the dark matter halo. On the other hand, other studies reported that the late-type spirals have fast bar. These inconsistent results would be caused by difference of measurement methods of bar pattern speed used in their studies. With the pattern speeds of bar derived from this observation, we will confirm whether there is a difference of bar type (fast bar or slow bar) depending on the morphological type by using our original method. | Spiral galaxies | Local Universe | 2018-10-25T07:38:14.000 |
| 497 | 2013.1.01383.S | 1 | Star formation in extreme environments: ram-pressure stripped gas in the "cosmic skidmark'' | We propose 2.86 hour ALMA Band 3 line and continuum mapping of a z=0.18 ram-pressure stripping candidate and the surrounding 20,000kpc$^{2}$ to investigate environmentally-driven galaxy evolution and star formation within extreme environments. This target, caught in the act of galaxy transformation as it accretes onto a group, shows evidence of an extended, gaseous plume extending over 55kpc from the galaxy core. High-resolution VLT-IFU data show [OII], [OIII] and H$\beta$ emission indicative of star formation throughout the plume, whilst deep g-band optical data reveals a complex structure of gaseous knots. Through simultaneous CO (1-0), CN (1-0) and SiO(3-2) line-emission mapping of this field, {\bf ALMA will reveal the location and properties of molecular cold gas reservoirs within this enigmatic system}. Continuum measurements will yield estimates of the [FIR] luminosity in order to characterise the dust within the tail. ALMA will provide a detailed outlook into the fate of a galaxy's cold gas supply when it interacts with the Intra-Cluster Medium (ICM). | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2016-04-21T20:35:32.000 |
| 498 | 2019.1.01190.S | 119 | Mapping the Ionizing Photon Rates from Luminous Starburst Galaxies in the local Universe | Thermal (free-free) radio continuum emission, which dominates microwave bands between 30 - 100 GHz (~90% at 33 GHz), is unbiased by dust and directly related to the ionizing photon production from newly-formed massive stars. Here we propose for 12.7 hours (8.5 on-source) of Band-3 continuum observations of 12 luminous starburst galaxies in the Great Observatories All-Sky LIRG Survey (GOALS) at matched-resolution (~2") to our 3 - 33 GHz VLA survey. With complete 3 - 100 GHz imaging we will accurately separate the synchrotron, thermal dust, and free-free emission components at 90 GHz, yielding some of the most precise measurements to date of the ionizing photon rates from extragalactic star-forming regions in starburst galaxies. These observations will be complemented by our MUSTANG-2 90 GHz campaign with the GBT to map 29 late-type galaxies in the Star Formation in Radio Survey (SFRS) with analogous 3 - 33 GHz imaging. Crucially, ALMA observations of the GOALS sample specifically target local, massive galaxies that are not contained in the SFRS, and whose resolved extra-nuclear SF regions have on average an order of magnitude higher SFR than those found in nearby normal galaxies. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2021-04-21T21:31:32.000 |
| 499 | 2023.1.00335.S | 0 | What drives the mini starburst in Sgr B2? | Sgr B2, a dense molecular cloud in the central molecular zone (CMZ) with a mass of 10^5 Msun, harbors one of the rare starbursts in the Milky Way. With an IR luminosity of 10^7 Lsun, numerous HII regions, H2O and CH3OH maser clusters, this cloud is forming a massive young cluster of more than 10^4 Msun of stars. Such an efficient star formation is remarkable especially given that the CMZ under produces stars by a factor of 10 more than in the Galactic disk. Why do the majority of the CMZ clouds under produce stars, while Sgr B2 fuels a mini starburst, despite the similar reservoir of dense gas and turbulence? The answer may lie in the magnetic field -- a weak field in Sgr B2 facilitates the starburst. This proposal is to map the magnetic field through dust polarization to test this hypothesis and pinpoints the role of magnetic fields in starburst. The outcome of the study will offer important clues to address the dichotomy of star formation in the CMZ. | High-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 500 | 2017.1.00987.S | 3 | Verifying locations of the scattering-induced polarization from a protoplanetary disk | We propose to perform polarization observation of the protoplanetary disk around HD 142527 with Band 4 to constrain the grain size at each position of the lopsided disk. HD 142527 has shown the polarized emission at submillimeter wavelengths from everywhere of the disk. The self-scattering of thermal dust emission plays a role at north region, but the other region can be interpreted as the dust alignment with toroidal magnetic fields as well. To investigate if the polarized emission from the other region is due to the scattering or alignment, we will investigate the wavelength dependence with this observation with Band 4. If the polarization fraction is completely different from Band 7, it would confirm that the self-scattering is the dominant mechanism in the whole disk. If not, we obtain the evidence of the toroidal magnetic fields. | Disks around low-mass stars | Disks and planet formation | 2019-02-20T14:20:39.000 |
| 501 | 2024.1.00711.S | 0 | A search for warm carbon-chain chemistry in the Integral-Shaped Filament | Protostars are rich and diverse in organic chemistry: some are overabundant in saturated organic molecules (hot corinos), while others are overabundant in carbon chains (WCCC objects). Did the Solar System experience a hot corino or a WCCC phase during its formation, or both? Recent searches for hot corinos in the Orion Integral-Shaped Filament (ISF), i.e. the nearest analog of the Solar System's natal environment, indicate a low detection fraction (~35%). In order to have a complete characterisation of the chemical nature of protostars, one should also firmly evaluate the presence of WCCC objects, which requires multi-line observations on 1000-3000 au scales at low frequencies, where carbon chains emit most strongly. This proposal aims to use bands 1 and 3 of ALMA to map the emission of several carbon chains/hydrocarbons in 25 protostellar cores along the ISF, to identify the number of WCCC objects present and characterise them. To our knowledge, this is the first systematic interferometric search of solar-mass WCCC objects in an analog of our Solar System's birthplace, a needed step to obtain the full picture of the chemical nature of protostars in this kind of environment. | Low-mass star formation, Astrochemistry | ISM and star formation | 2025-11-02T22:47:05.000 |
| 502 | 2016.1.00560.S | 20 | Resolving the turbulent ambipolar diffusion scale in molecular clouds with ALMA | We aim to use ALMA to probe the turbulent power spectrum and resolve its energy dissipation scale in the M17 molecular cloud. This length scale is typically on the order of several mpc and is due to turbulent ambipolar diffusion, i.e., the spatial wavelength range where the motions of ion and neutral species decouple from each other. Importantly, this ambipolar diffusion scale is a measure of the magnetic field strength in the plane of the sky. In a previous study, Li & Houde (2008) determined a dissipation length scale of approximately 0.2" (~2 mpc) for M17 using single-dish maps of a pair of coexistent ion and neutral molecules, HCN and HCO+, and comparing the velocity dispersions stemming from their corresponding J=4-3 spectral lines. We propose to revisit the region in this source where we found the lowest levels of turbulence (narrowest spectral line-widths) at the single-dish angular resolution of Li & Houde (2008). We aim to use the power of ALMA to cover a range of spatial scales spanning almost two decades of the turbulent power spectrum, from 10" down to near the predicted energy dissipation length scale (i.e., 0.4"). | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-07-28T19:14:45.000 |
| 503 | 2015.1.00568.S | 87 | Resolved Dust in the Hottest and Coldest SMGs: What does dust temperature really tell us? | Locally, nearly all extreme starbursts are triggered by major galaxy mergers, but recent work suggests that at high-z, their high star formation rates are instead fueled by either steady gas inflow or minor mergers. Also recently, new infrared observatories like Herschel and SCUBA-2 have dramatically increased the number and diversity of known high-z extreme starbursts, demonstrating that they dominate cosmic star formation at 1 | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2017-07-14T20:34:32.000 |
| 504 | 2022.1.01562.S | 207 | Dust in galaxies at z=8-11 | Over the past decade, it has become increasingly evident that a significant amount of dust is present in galaxies during the reionization epoch, defying our theoretical expectations. Here we propose dust continuum observations for every bright (H=24.5-26.5AB, N=23) Lyman Break Galaxy (LBG) candidate at z=8-11 with approved spectroscopic JWST GO1 observations. With Band 7 measurements at ~88um rest-frame, we will efficiently complete the first census of the emergence of dust and obscured star-forming activity at z=8-11 in all 23 targets, which are inaccessible to JWST. Based on recent ALMA studies at z~6-9, we also expect to serendipitously detect the [OIII]88um line from ~30% of the targets by carefully choosing each frequency setup. These observations are highly timely and complementary to the JWST program, and they will allow us to constrain the process of dust formation and destruction in the early universe. | Lyman Break Galaxies (LBG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2024-03-01T21:56:23.000 |
| 505 | 2015.1.01324.S | 12 | Star formation: in and around galaxy clusters | We propose to measure the intensity of the CO(3-2) line as well as its associated continuum in 18 main sequence star-forming spiral galaxies in and around a medium mass galaxy cluster at intermediate redshift. CL1411.1-1148 is a unique analog to the progenitor of clusters in the local universe, with well identified large scale structures up to very large cluster-centric distance. From this observations, H2 masses will be estimated in galaxies distributed over the full range of local densities, 2 to 30 gal/Mpc2: from low density, to filaments, to groups and cluster. Our goal is to address fundamental questions relating to the growth of galaxies and cosmic structures: how do galaxies evolve in the cosmic web, which processes quenches star formation, where do they take place, on which time scales. Our dataset will provide the first ever glimpse as to how gas is affected by cosmic structures when galaxy transformation was in full swing. | Galaxy groups and clusters | Cosmology | 2017-08-05T16:43:07.000 |
| 506 | 2019.1.00796.S | 31 | Mapping CO Emission in eta Carinae During Periastron Passage with ALMA | In Cycle 6 we were awarded Director's time to observe 12CO and 13CO 2-1, 12CO 1-0, and H30-alpha in the Homunculus nebula of the LBV eta Carinae, just before the central massive binary enters periastron. This occurs every 5.54 years, and is accompanied by a sharp reduction of the ionizing radiation field as the hotter companion is enveloped in the dense wind of the more massive primary star. Our goal is to provide a detailed physical description of the shielding structures associated the kinematic components of CO during the ionization high state, complemented by parallel space and ground-based observations. In Cycle 7 we propose to re-observe low-J CO while the X-ray/UV light curve is at minimum in early 2020, and again ~3 months later during recovery to maximum fluences, following the time evolution of the plasma with the onset of disturbances in the X-ray and UV radiation field. This is a rare opportunity to explore gas that reflects CNO-process abundances in a UV-dominated molecular chemistry, and elucidate on the CO formation pathway, rewarding us also with insight into eta Car's role in a broader paradigm for pre-SN LBV activity related to stellar mergers. | Evolved stars - Shaping/physical structure, Luminous Blue Variables (LBV) | Stars and stellar evolution | 2022-10-13T19:10:57.000 |
| 507 | 2015.1.00908.S | 59 | Thackeray's Globules | Thackeray's globules in IC 2944 are perhaps the most famous of the many small groups of compact cloud fragments commonly found in HII regions. Our SEST mm-wavelength observations of this complex reveal large velocity differences of order 20 km/s among the globules, indicating that the globules are short-lived and are being accelerated, compressed, and perhaps destroyed by radiation fields and winds from the cluster of OB stars in IC 2944. These processes are likely fast, precluding the formation of stars, consistent with the absence of any signs of star formation. We propose to observe the main globule and its entourage of small fragments and splinters with ALMA in (13)CO, C(18)O,and CS to study their column and volume density structure, radial velocities, and line-widths. High resolution ALMA observations, supported by detailed modeling with a newly developed code, will for the first time allow us to distinguish between competing scenarios for the evolution of dense neutral clouds immersed in the EUV+FUV radiation field of a cluster of massive stars. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-06-14T19:05:51.000 |
| 508 | 2013.1.00661.S | 5 | Measuring the mass in the nebula around Eta Carinae | Eta Carinae is the most important of the unstable luminous blue variables (LBVs), and its 19th century Great Eruption is the prototype for eruptive mass ejections that dominate the evolution of very massive stars. Eta Car is unique as the only LBV that has both a detailed photometric record of its eruption and a spatially resolved nebula created by that event for which we can measure the mass directly. Moreover, light echoes from Eta Car's eruption now allow us to reconstruct a spectroscopic time series of the eruption, showing absorption from newly formed molecules. The dust and molecules that formed have now cooled, and the products can be observed directly with ALMA. Previous single-dish submm observations find a nebular mass of 40 solar masses, but the angular resolution of ALMA is required to determine how much of this mass resides in the nebula ejected in the 19th century. Our primary goal in this proposal is to spatially resolve the dust and free-free emission in multiple bands and to definitively measure the total dust mass. The molecular lines will map the 3D kinematics of the nebula and constrain the basic physical conditions and chemistry in the molecular shell. | Transients | Stars and stellar evolution | 2016-10-29T08:12:54.000 |
| 509 | 2021.1.01328.S | 405 | Testing to ~100pc the co-spatiality of intense star formation and supermassive black hole growth at z ~ 2 | The growth of supermassive black holes and the formation of stars both peak at z~2, processes that must be linked to preserve the relation between black hole and stellar mass in galaxy bulges. But how is this link formed and maintained? Locally, there is little relation between the rate of black hole accretion and the global star formation (SF) in a galaxy, implying at most a very indirect link at the current epoch. We will pinpoint the location of the sites of intense SF and active galactic nuclei (AGN) at z~2, observing galaxies selected from the COSMOS 3 GHz VLA survey to have radio emission >5x more luminous than the level associated with their SF. The large excess ensures that the radio emission is AGN-dominated; ALMA at 870 micron traces virtually pure SF. The sub-arcsec, high S/N VLA and ALMA images will localize the AGN in relation to the intense SF regions with ~100 pc precision. Early results on three galaxies show the AGN and SF to be cospatial, consistent with concurrent, in-situ coevolution at z~2. We propose to localize the intense SF in 55 AGNs to test this scenario definitively, and further resolve the morphology of SF (nucleated vs. extended) in these AGN hosts. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-09-07T15:28:02.000 |
| 510 | 2022.1.01564.S | 25 | Resolved gas kinematics of highly star-forming protocluster galaxies | We propose a study of the gas kinematics of two highly star-forming protocluster galaxies at z~2.6 to reveal the mechanisms that fuel their star-formation activity, and lead to the build up of their massive stellar and gas reservoirs. The selected targets are situated in an overdense Planck-selected protocluster for which low-resolution sub-mm and CO observations are available, and JWST/NIRCam multi-band imaging observations will be obtained. The available data indicate that these sources have massive and extended reservoirs of gas at low excitation producing more than 1000 Msun/yr. It is also plausible that they are affected by multiplicity or strong gravitational lensing. We request ALMA CO and continuum observations at high spatial resolution of these protocluster galaxies to determine, through a morphological and kinematical analysis of their molecular gas reservoir, the physical mechanisms behind their prodigious star-forming activity. This program will increase the limited number of protocluster galaxies at z~2-3 with known gas kinematics, and hence the possibility of investigating the link between local cluster galaxies and their predecessors at higher redshifts. | Starbursts, star formation | Active galaxies | 2024-09-29T13:49:38.000 |
| 511 | 2015.1.01012.S | 20 | Disentangling the molecular gas content in gas-rich galaxies at z ~ 0.15 | In this proposal we search for "local" analogues of high-z galaxies. From our previous experiments, we have identified a handful of gas-rich galaxies, f_gas=MH2/(MH2+Mstar)>0.3 at z~0.1-0.2, which could be perfect laboratories to understand the star-forming physics seen in gas rich galaxies at z>1. One of the most striking differences between the nearby and the high-z star-formation activity is the presence of giant molecular clumps in gas-rich disk-galaxies which can be as 100-1000x more massive than those seen locally. Is it therefore imperative to understand (from more nearby objects) the dynamical processes that give birth to those high-z gas-rich and highly turbulent disks -- dominated by high surface brightness and velocity dispersions. As a follow-up campaign, in this proposal, we target three bright f_gas>0.3 galaxies to resolve at 0.6" resolution (~kpc-scale rest-frame) the structure and the dynamics of these recently discovered galaxies at z~0.1-0.2. At the exquisite signal-to-noise provided by their nearby nature, we can put thight constraints on the internal properties of these galaxies, including Larson's relations for the different molecular gas regions. | Galaxy structure & evolution | Galaxy evolution | 2017-12-09T13:50:03.000 |
| 512 | 2023.1.01152.S | 0 | Radial Distributions of Sufur-Bearing Species in Disk Forming Regions | Sulfur-bearing species (S-species) are now spotlighted in astrochemistry and astrophysics. First, S-species such as H2CS and OCS are found to trace the protostellar and protoplanetary disks around Solar-type protostars. Second, they are detected in the Solar System comet, suggesting a possible link between the interstellar and planetary chemistry. Although chemical differentiation of S-species is recognized in disk-forming regions, it is not understood in terms of chemical processes. This is because the distributions of S-species, including H2S the major reservoir of S-atoms specifically, in disk-forming regions are still obscure. To overcome this situation, we here propose to delineate the radial distributions of fundamental S-species in Band 5 at a high-angular resolution toward five young protostellar sources: IRAS 16293-2422, Serpens SMM 1/4, B335, and Elias 29. We also evaluate the temperature distribution in disk-forming regions by using the multiple lines of H2CS. The result will constitute a valuable template for studies on sulfur chemistry in protostellar sources. | Low-mass star formation, Astrochemistry | ISM and star formation | 2025-07-24T12:58:53.000 |
| 513 | 2018.1.00981.S | 15 | Evolutionarily Young Filamentary Region of NGC 6334 | The filamentary nature of the interstellar medium and molecular clouds fuels questions about the mass assembly of molecular clumps and dense cores within these non-spherical structures. We will investigate the northeast section of the NGC 6334 filament, which is an evolutionarily young filamentary region according to our recently-delivered ACA data. We have found that the NH2D and SiO emission in NGC 6334 are mainly distributed in the northeast section, which suggests that the filamentary structures in this section have recently formed. This new ALMA 12m array + ACA spectral line mosaic with significantly-improved angular resolution and sensitivity will resolve the filamentary structures at the early stage of evolution. The new observations will address questions of how mass is accreting onto dense cores within the young filaments and whether the SiO emission is generated by outflows or shocks from converging flows. We will also be able to investigate the dense cores, protostars, and turbulence across this young filamentary region. | High-mass star formation | ISM and star formation | 2020-12-23T16:13:42.000 |
| 514 | 2016.2.00048.S | 21 | Cold atomic halo around the massive Spiderweb Galaxy: lighting up the hidden molecular Universe with the ACA | Our view on the molecular Universe may be severely biased. As we will explain, technical limitations have prevented us from efficiently recovering all of the cold gas in circum- and inter-galactic environments. Using low-surface-brightness mm techniques, we discovered a giant halo of cold molecular gas that surrounds the massive Spiderweb Galaxy in a proto-cluster at z=2.2. An estimated 10^11 solar masses of molecular gas is detected in CO(1-0) across ~70 kpc, where it fuels in-situ star formation within the intra-cluster medium. ALMA cycle-3 data revealed the presence of widespread atomic [CI], but the surface-brightness sensitivity of these cycle-3 data is insufficient to compare the [CI] with the CO and Ly-alpha across the full extent of the halo. We propose ACA observations of [CI] to image -for the first time- atomic gas across the >100 kpc halo environment of a massive high-z galaxy. We will use this to derive the true mass and chemistry of the cold intra-cluster gas, and study its nature and origin. This project will shed light on the early formation stages of the most massive galaxies, and will open an exciting new window on the molecular Universe for ALMA to explore. | Lyman Alpha Emitters/Blobs (LAE/LAB), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2018-11-09T18:46:34.000 |
| 515 | 2021.1.00374.S | 60 | Understanding the Physical Origin of [CII] Deficit in Early Star-Forming Galaxies | The ionising output of early star-forming galaxies is key to understanding their role in cosmic reionisation. A detailed survey of a large sample of z=3 Lyman alpha emitters (LAEs) whose intense [OIII] 5007A emission indicates they are useful analogues of galaxies in the reionisation era at z>6. A now completed deep HST F336W imaging campaign finds a surprisingly high fraction show prominent Lyman continuum leakage with escape fractions ranging from 13 to 60%. Photoionisation models indicate such high escape fractions may arise from star-forming regions that are density- (rather than radiation-) bound, consistent also with the high [OIII] to [OII] line ratios. Such star-forming regions may also explain the puzzling ``[CII] 158um deficit'' seen in several high redshift galaxies given that line partly originates from photo-dissociation regions. We request time to complete a study of [CII] emission to confirm a tentative correlation seen between our individually-measured escape fractions and the strength of [CII] consistent with the density-bound hypothesis. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2023-04-15T10:27:48.000 |
| 516 | 2016.1.00166.S | 0 | Measuring the Chromospheric Thermal Structure in Active Regions on the Sun | A sunspot is a relatively big area on the solar surface (i.e., the photosphere), which appears darker than the surrounding quiet sun. The darkest area in the center of a sunspot is called umbra, while the less dark, filamentary belt around it is called penumbra. The darkening of sunspots is due to strongly enhanced magnetic fields, which inhibit convection and, thus, the heat transfer from below, resulting in a lower temperature of the sunspot than the quiet sun. An area covering a group of sunspots and other magnetically active elements of the photosphere is called Active Region. Here we propose to measure with high spatial resolution the temperature distribution in the chromosphere in an Active Region. This thermal structure is central to all of the chromospheric physics including all possible dynamic phenomena. However, it is currently very poorly constrained by limited low-resolution observations only, which, in addition, appear to strongly disagree with available chromospheric models. The proposal will directly address the puzzling discrepancy between the models and available data and will lead to highly advanced understanding of the chromospheric thermal structure. | The Sun | Sun | 2018-08-29T06:06:37.000 |
| 517 | 2015.1.01489.S | 11 | Outflows and Dissipation in a distant QSO and SMG pair: Where does the energy go? | The source BRI 1202-0725 is a well studied group of galaxies consisting of an interacting pair of a QSO and a SMG, and a pair of Lyman-alpha emitters at z~4.7. The QSO and SMG, despite having intense star formation and a powerful QSO do not appear to be driving significant outflows in the dense molecular gas. It may be that their outflow is in the diffuse molecular gas, something not yet probed. However, if they are not driving outflows, then were does the energy injected into their ISM go? To investigate this puzzle, we take advantage of this unique configuration of galaxies to 1) constrain robustly their outflow rates in the diffuse molecular gas using the HF J=1-0 absorption line; and 2) if they don't have outflows, estimate their turbulent dissipation rates using the H2O 220-211 line which should be bright compared to other molecular gas tracers. HF J=1-0 is an excellent tracer of diffuse molecular gas, even gas with relative low extinctions (Av<0.5 magnitudes). WIth the wealth of CO, CI, [CII] lines that have been observed will allow us to constrain the excitation of H2O and use it as a tracer of turbulent dissipation. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-07-23T00:30:55.000 |
| 518 | 2015.1.00977.S | 21 | Understanding the Formation of Globular Clusters | In Cycle 0 observations, we identified an extraordinary molecular cloud with the properties required to form a globular cluster (including size and mass). The lack of associated thermal radio emission indicates that star formation has not yet altered the environment, and places this cloud at a very early stage of evolution. Given the extremely short lifetime expected for this phase of cluster evolution (< 1Myr), we expect clouds such as this to be exceptionally rare, which is reflected by the fact that this is the only such cloud identified in the ALMA Antennae data set. Thus, we have the opportunity to determine the physical conditions in a proto-globular cluster molecular cloud -- before these conditions have been disrupted by star formation -- for the first time. With this proposal we seek to determine the resolved physical conditions in this cloud, constraining possible formation mechanisms. We propose ~0.1" (=10 pc, 5x better than the Cycle 0 observations) imaging of this singular molecular cloud in 12CO(2-1), 12CO(3-2), 13CO(2-1) to determine its basic physical properties including mass, size, linewidth, and temperature. | High-mass star formation | ISM and star formation | 2018-04-22T04:25:17.000 |
| 519 | 2017.1.01522.S | 19 | Searching for magnetic dust and missing iron around L2 Puppis | Magnetic dust simultaneously offers solutions to long-standing issues, and also a potential problem. It would answer a fundamental problem of Galactic chemistry: where is the iron in the interstellar medium? It may also be responsible for the excess dust emission seen at <=200 GHz. It is expected to show a characteristic polarisation behavior in the sub-mm is expected. However, this very signature would present a problematic foreground for observing primordial B-modes from the cosmic microwave background (CMB). We propose to use ALMAs band 3 and 6 polarisation capabilities to observe the stellar ejecta of L 2 Pup, the second nearest AGB star, to look for evidence of magnetic dust. | Post-AGB stars | Stars and stellar evolution | 2019-04-04T15:54:01.000 |
| 520 | 2023.1.01229.S | 0 | First star-forming galaxy as plausible electro-magnetic counterpart of Neutrino events | We propose to perform a spectral scan for the plausible electromagnetic (EM) wave counterpart of the newly discovered IceCube event, IceCube-210922A. The source is discovered as a bright submillimeter object without temporal variability, and its broadband SED implies a dusty star-forming galaxy, which is one of the expected major contributors of astrophysical neutrinos. The intensive follow-ups for the IceCube-210922A field did not find any other EM candidates and indicated that the bright submillimeter object is the more plausible EM counterpart. The primary goal is the redshift estimation of the submillimeter source. This observation also allows estimating essential physical parameters (star formation rate and molecular gas mas) to discuss the neutrino flux. The timely characterization of the EM counterpart is critical to enhancing multi-messenger astronomy in the era of its dawn. Especially, the first EM counterpart associated with the non-transient type breaks new ground. The initial demonstration would become the new framework for identifying EM counterparts, and new intensive searches could also be managed for newly discovered events and previously detected neutrino events. | Starbursts, star formation | Active galaxies | 2025-08-02T21:38:26.000 |
| 521 | 2018.1.01188.S | 170 | A Comprehensive Study of Quasar Host Galaxy and Cosmic Reionization with a Large Statistical Quasar Sample at z>6.5 | The detection of intergalactic medium (IGM) damping wing absorption profiles in the spectra of only two z>7 quasar suggests that we are witnessing the epoch of reionization (EoR). Recently, our group have doubled the number of known quasars at z>6.5, establishing the first statistical sample of EoR quasars. The quasar luminosity function measured from this sample indicates the decline of quasar number density accelerated at z>6.5, strongly suggesting a new phase of quasar evolution close to the epoch of the earliest supermassive black hole (SMBH) formation. Here, we propose to observe a complete quasar sample (twelve quasars total, the majority are unpublished) at EoR to detect the [CII] and continuum emission in their host galaxies. The ALMA observations will measure star formation rate and constrain dynamical mass, enabling the first statistical study of the coevolution of SMBHs and host galaxies during EoR. We will identify [CII] companions and search for the signatures of galaxy merger and AGN feedback. Furthermore, the precise [CII] redshift measurements will be crucial in modeling IGM absorption and in identifying young quasars using proximity zone measurement at EoR. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2020-01-19T01:41:44.000 |
| 522 | 2015.1.00418.S | 0 | Probing Accretion Flows from Filaments to Massive Star-Forming Cores | We propose to investigate filamentary accretion flows in the remarkable IRDC complexes, M17 SWex, where a delayed onset of massive star formation has been reported. Such delay may be explained by a longer accretion time for high-mass end of protostar mass function. Indeed, the dense clumps in this IRDC are found to be at the convergence of multiple filaments of parsec length and display the morphology of hub-filament systems. These hubs are likely nurturing massive protostars and accrete mass through their connecting filaments. We plan to 1) determine the mass accretion rate through filaments to hubs by observing the inflow motions along filaments with N2H+ (1-0); 2) assess the fragmentation in the filaments by identifying dense cores with the continuum and N2H+ emissions; 3) estimate mass accretion onto filaments from the surroudnings by analyzing the self-absorption feature in the HNC (1-0) spectra; 4) search for hot molecular cores with CH3CN lines. We will conduct a mosaic of 97 pointings in the C36-1 configuration in Band 3 to cover two hubs and their associated filaments | High-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 523 | 2021.2.00176.S | 189 | SPT0303-59: The most extreme protocluster candidate from the SPT sample | In the local universe about half of all galaxies live in clusters and galaxy over-densities. But in the past decade most observational efforts to investigate galaxy evolution have focused on the evolution of field galaxies through cosmic time. Studies of the evolution of clustered environments have been proven to be much more challenging due to difficulties to find high redshift protocluster (PC) candidates in significant numbers. With the advent of blind mm/submm surveys with Herschel and the South Pole Telescope, covering 1/16th of the sky, the situation has improved significantly and the number of published PC candidates at high redshift is finally ramping up. In this proposal we focus on a a spectacular over-density of dusty, highly star-forming galaxies discovered by APEX/LABOCA in a field initially selected from the South Pole Telescope survey. If confirmed as a coherent structure, it would be the most actively star forming PC discovered in the entire SPT survey. It is unlikely that many other of these systems can be found in the entire sky. So far only a photometric redshift is available for this source, which we aim to change with this proposal. | Galaxy Clusters | Cosmology | 2023-09-20T16:00:06.000 |
| 524 | 2017.1.00240.S | 4 | Protostellar Multiplicity in Isolation | Multiple star systems are a common outcome of star formation. While the multiplicity frequency and separation distribution are well-characterized for field stars, theoretical studies predict that the majority of multiple systems form very early in the protostellar phase and undergo significant and rapid dynamical evolution. Thus knowledge of the intrinsic multiplicity fraction and separation distribution before modification via dynamical evolution requires studying the youngest objects: protostars still embedded in and accreting from their parent cores. Recent surveys have made great progress in characterizing protostellar multiplicity in clustered environments but have left unanswered a key question: does the formation of multiple systems depend on environment? Here we propose to finish a partially completed ALMA band 6 survey to measure the multiplicity fraction and separation distribution in truly isolated protostellar cores to confirm tantalizing but statistically unconfirmed results suggesting that multiplicity strongly depends on environment. | Low-mass star formation | ISM and star formation | 2019-03-07T18:29:19.000 |
| 525 | 2018.1.01687.S | 212 | Resolving the complete outflow density and kinematics structures by observing [CI] (1-0) | We take the advantage of the newly available, ACA stand-alone observational capability at Band 8 to propose high sensitivity, high signal-to-noise ratio(S/N) observations of the [CI]3P1-3P0 emission line in the local molecular outflows. We aim to explore the capability of the [CI](1-0) line to trace the outflow mass and compare it with the more commonly employed CO line gas tracers. Our survey will address the doubts raised from earlier outflow analysis by CO due to advantages of [CI](1-0), i.e., optically thin, simpler energy-level system, and low self-absorption. Our analysis will leave a rich legacy for future ALMA research beyond its justificataion on [CI](1-0) as a molecular outflow tracer. [CI](1-0) is a potential magnetic field tracer with the maximum polarization more than 20%. The survey of [CI](1-0) intensity in the outflow near FUV radiation helps to source selection for future atomic polarization measurement on interstellar magnetic field. | Outflows, jets and ionized winds | ISM and star formation | 2020-09-12T21:16:50.000 |
| 526 | 2018.1.00252.S | 32 | Dissecting the monolithic molecular core G31.41+0.31 | In a previous ALMA project we imaged the massive core G31.41+0.31 at 1.3mm with 0.2" resolution. The results provide us with contradictory evidence: on the one hand, (i) the core looks very homogeneous and appears to undergo solid-body rotation; on the other hand, (ii) we find evidence of rotation+infall that speeds up towards the core center, while the presence of two embedded massive stars suggests that fragmentation has already occurred. We believe that the apparent contradiction between (i) and (ii) can be due to large continuum opacity at 1.3mm and insufficient angular resolution. Therefore, to establish whether the core is indeed as monolithic as it appears, or is undergoing global fragmentation, we propose to extend the continuum imaging to 3mm, at the maximum possible resolution at this band (0.08"). At 3mm the dust opacity is up to 4 times lower and it should be easier to reveal fragmentation on scales of ~0.2", comparable both to the Jeans length and the separation of the two embedded massive stars. | High-mass star formation | ISM and star formation | 2020-11-09T16:24:06.000 |
| 527 | 2013.1.00061.S | 14 | Investigating the water deuteration in a young protostellar system | The evolution of water from its formation in the molecular cloud until its incorporation in the protoplanetary disk and then comets and asteroids is still unclear. Measuring the water D/H ratio is particularly helpful to answer this question. We propose to carry out multi-line observations of the water isotopologues (HDO, H2-18O and D2O) at high spatial resolution (0.3arcsec, 35 AU diameter) towards the inner regions of the well-known Class 0 protobinary IRAS16293-2422, which is now possible thanks to the enhanced capabilities of ALMA cycle 2. Through the study of the kinematics and the determination of the HDO/H2O and D2O/H2O ratios with radius from the protostars, we can determine if the water present at the Class 0 stage was preserved or reprocessed until its incorporation in disks and primitive icy bodies. The data will also allow us to determine the mechanisms that control the water vapor abundance in the warm inner regions of Class 0 protostars. | Low-mass star formation, Astrochemistry | ISM and star formation | 2015-11-13T15:23:35.000 |
| 528 | 2022.1.00055.S | 280 | SERENADE: Systematic Exploration at Reionization Epoch using Nebula And Dust Emission | ALMA has played a distinct role in z>~6 galaxy studies through its unique probe of FIR diagnostic emission lines such as [OIII]88um and [CII]158um, as well as dust continuum. The line ratio of [OIII]/[CII] is particularly informative because it reflects physical conditions of the ISM due to their different ionization potentials. Previous studies report redshift evolution of the [OIII]/[CII] ratio from z~0 to z>6 and its tentative correlations with galaxy properties, but these results are based on only less than 10 galaxies. Here we propose to conduct the first systematic program observing [OIII] and [CII] lines of 20 spectroscopically-confirmed galaxies at z~6, where Lya is visible and easily accessible from ground-based optical instruments, and both [OIII] and [CII] can be observed with ALMA. We will 1) measure [OIII]/[CII] ratios and its correlations with various galaxy properties (e.g., SFR, bolometric luminosity, Lya equivalent width) to study ISM physics and the escape of ionizing photons at the epoch of reionization, and 2) estimate dust temperatures using multi-band continuum observations to understand nature of some high redshift galaxies with very high dust temperatures. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-12-27T02:13:00.000 |
| 529 | 2013.1.00359.S | 3 | What lies outside super-Earth planetary systems? | We propose to image the debris disk of the nearby (8.5pc) main sequence G5V star 61Vir in band 7 at 1.08” resolution to determine the disk structure at a resolution ~5 times better than previous observations. This system hosts at least 2 super-Earth planets within 0.5AU, a configuration which is common (around ~50% nearby stars), but the origin of which defies explanation. We recently showed this system has a debris disk with peak brightness at 30-100AU, and that bright disks such as this are more frequently found around super-Earth systems (Wyatt et al. 2012). Little is known about what lies in the empty region 0.5-30AU which must hold clues to the origin and nature of systems with super-Earth planets. We will image the debris disk and use radial and azimuthal structures within its planetesimal belts to set constraints on planets at >0.5AU, not only their current masses and orbits, but also their dynamical history. In this way we will assess different models for the formation of super-Earth planetary systems. The proximity and sub-mm brightness of 61Vir makes it uniquely placed to test such models, and the premier laboratory for understanding the ubiquitous class of super-Earths. | Debris disks | Disks and planet formation | 2016-06-23T18:36:48.000 |
| 530 | 2013.1.00897.S | 2 | Constraining the agents of change - the impact of clumpy winds on massive stellar evolution | There is considerable evidence for structure (clumping) in the radiatively driven stellar winds of hot stars. The existence of clumping has important consequences for mass-loss rate determinations. Mass-loss rates that are not corrected for clumping provide incorrect inputs for stellar and galactic evolution models. ALMA observations are ideally suited to study the effect of clumping in the critical (intermediate) regions of the wind. We propose to measure the 3 mm continuum fluxes of a sample of OB stars in the strategically important massive stellar cluster Westerlund 1, for which we already have optical, near-IR and radio measurements. The ALMA observations will substantially increase the observational material, allowing us to uniquely constrain clumping gradients and thus advance our understanding of wind clumping and its relation to stellar and wind parameters. The quantitative information derived in this project will ultimately allow is to correct massive star mass-loss rates for clumping and put considerable constraints on the theoretical models, which is vital to our understanding of the hydrodynamics of these winds. | Main sequence stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2016-11-16T00:21:51.000 |
| 531 | 2023.1.00295.S | 0 | The earliest stages of interstellar organic chemistry: a first survey of CH3CN in diffuse clouds | The headstream of interstellar organic chemistry needs to be pushed forward from dark clouds-only environments into diffuse clouds-included ones. Diffuse clouds have similar chemical composition to dark clouds, which harbor a lot of large organic molecules. For example, the abundance ratios of c-C3H2, l-C3H2, CCH, and CH in diffuse clouds are comparable with those in dark clouds. This suggests that a diffuse cloud is the source of interstellar organic chemistry at its earliest stages. Probing the accurate abundances of the large organic molecule CH3CN in diffuse clouds is necessary to understand their role in the early stages of organic chemistry. We plan to detect absorption lines of the J = 5-4 and 6-5 rotational transitions of CH3CN in diffuse clouds toward the Galactic-Center black hole Sagittarius A* having a strong continuum emission. This molecule has a physical advantage "hot axis effect," which leads to strong absorption lines of rotational transitions from J=K levels in diffuse clouds. By taking into account this important effect, our measurements will provide accurate abundances of CH3CN in diffuse clouds. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-01-22T15:53:30.000 |
| 532 | 2023.1.00259.S | 0 | Clumps of Molecular Gas in the Turbulent, Gas-Rich DYNAMO Galaxies | Normal, main-sequence galaxies at cosmic noon have morphologies dominated by massive star forming clumps. These clumps are potentially linked to the morphological transformation of these galaxies, if they are long-lived, bound structures. Yet, aside from a handful of extreme systems, it is difficult to acquire high-resolution observations to characterize the molecular gas content and depletion times of clumps. We will address this with ALMA CO(3-2) mapping at 0.2'' (~280 pc) in 5 nearby DYNAMO galaxies, whose properties are very similar to those of main-sequence galaxies at z ~ 1-3. On a sample of 80 clumps we will: study the gas fraction, depletion times, and kinematics of individual clumps to determine if (1) clumps of star formation and stellar mass correspond to those of molecular gas, and (2) determine if they are bound (and thus long-lived) through their virial parameter. These observations will allow us to provide valuable insight into currently outstanding questions that are crucial for deriving models of galaxy evolution. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2025-07-20T14:01:11.000 |
| 533 | 2019.1.01447.S | 29 | Diffuse cold atomic gas in Seyfert galaxies: to reveal multi-phase nature of AGN obscuration | Recent high resolution observations of both dense molecular and diffuse atomic gas in the Circinus galaxy showed consistent physical/dynamical properties to what expected in the multi-phase fountain torus model, which may explain the physical origin of AGN tori. As an international collaboration of AGN researchers (GATOS), we here propose high resolution (0.1" ~ 10 pc) [CI](1-0) observations toward 2 nearby Seyfert galaxies to test the fountain model in a wider parameter space. Importantly, we already have the same resolution CO(3-2) data of these objects, allowing us to study the multi-phase nature of the tori straightforwardly. With this short time program, we will investigate the density structure of the tori, as well as the existence of atomic outflows (a key process to maintain the fountain torus structure): our dedicated simulations will be useful for these purposes. We can also study the intriguing dependence of the torus's geometrical structure on an Eddington ratio, which was suggested by recent hard X-ray surveys. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2022-07-12T20:42:28.000 |
| 534 | 2022.1.00111.S | 6 | Mass-loss and the evolution of the most massive stars in the Galaxy | Massive stars impact on fields as diverse as galactic evolution, core-collapse SNe and the birth of black holes and neutron stars; the latter particularly relevant with the dawn of gravitational wave astronomy. However, we lack a complete understanding of their evolution: for a star of given mass we cannot yet predict how it will die, nor the nature of the resulting relativistic remnant. This is the result of the lack of a theoretical framework for quantifying mass-loss, with evolutionary codes relying on empirical constraints which, at worst, are uncertain at the order of magnitude level. Consequently, we propose to observe the Arches cluster, which contains very large numbers of very massive (>60 Msun) stars for which we may obtain mass-loss rates via simultaneous quantitative analysis of extant VLT spectroscopy, HST photometry and critically, ALMA mm-continuum observations. This will provide a unique insight into the dependance of mass-loss on properties such as stellar mass and luminosity for the most massive stars that nature permits; essential input physics for stellar evolutionary models as well as spectral and population synthesis codes. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-07-03T19:09:25.000 |
| 535 | 2021.2.00123.S | 22 | A CO emission follow-up survey of the DINGO Pilot survey: the evolution of molecular gas over the past 3 Gyrs | The differing evolutions of the cosmic densities of gas and star formation post the cosmic noon (z<2) is a subject of intense ongoing research. Recent comparative measurements of the cosmic densities of SFR, stars, atomic hydrogen (HI) and molecular hydrogen (H_2) suggest that it is necessary over the past Gyrs for (i) the HI reservoirs of galaxies to replenish through infall, and (ii) HI to convert to H_2 at the centres of galaxies, in a fine balancing act as the molecular gas depletion timescale does not change with redshift, while HI density is higher than H_2 density at all redshifts. To disentangle this process we need to measure the H_2-to-HI content in the same set of galaxies in bins of stellar mass, SFR, and environment, and at different redshifts. DINGO is an ongoing survey of HI upto z=0.43 in the GAMA survey regions, which is making it possible for the first time to undertake such a study. We propose a pilot survey to observe the CO(1-0) line emission using standalone ACA from galaxies within the central 1 deg. x 1 deg. area observed in the DINGO pilot survey, in two redshift ranges covering upto z=0.26 (past 3 Gyrs), and use stacking to reach our science objectives. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2023-01-31T09:54:58.000 |
| 536 | 2022.1.00500.S | 19 | The onset of contraction in a magnetized prestellar core | Prestellar cores are ideal objects to study the onset of gravitational contraction. In this process, magnetic fields represent an additional source of support against the gravitational pull and, for this reason, diffusive mechanisms such as ambipolar diffusion are invoked to allow for core collapse. Preliminary observations of dense gas tracers in the highly magnetized FeSt 1-457 prestellar core show hints of velocity drift between ions and neutral molecular species. This object has a centrally peaked dust distribution and evolved prestellar chemistry (bright deuterated lines). With this proposal, we aim to resolve the dust structure and the gas kinematics at the core center. The dust maps will reveal if any fragmentation and/or dust streamers are detected at the core center, while the spectral line data, N2D+ and DCN, will trace the dense gas kinematics. If the neutral gas is decoupled from the ions and magnetic field lines, this effect will be enhanced in interferometric maps since gravity is stronger in the core center. The observations will be compared against the predictions of non-ideal MHD simulations and comprehensive deuterium chemistry models. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2024-05-29T20:25:49.000 |
| 537 | 2017.1.01644.S | 71 | Searching for Kuiper-Belt analogues around the closest M-dwarf planetary systems | Debris disks are the result of planetary formation and are expected to be present in mature planetary systems in the form of left-over material reservoirs, as in the case of the Solar System. This has been confirmed for the early stages of planet formation, in very young stars, and for later stages in AFGK spectral-type stars. However, very few examples of detection around old M dwarfs exist, very little is known on their occurrence and even less on any correlation with the planets their stars host. Our recent ACA observations detect dust around our closest neighbour, Proxima Centauri, host of the habitable planet Proxima b. We request ACA observing time in band 6 to build on this first achievement and detect these disks on four of the closest, best known planetary-system-hosting M dwarfs. If successful with this proposal, we will shed light on issues like the star-planet system architecture, the occurence of these disks around old M dwarfs, correlations with their planets, and even provide a new way, through the measuring of the disk inclination angle, of obtaining the absolute mass for planets that, having been detected by the Doppler technique, have only minimum mass estimates. | Debris disks, Exo-planets | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 538 | 2013.A.00007.T | 0 | Measuring the Distance to Pluto | Pluto's distance maps directly into the arrival time for the New Horizons spacecraft flyby of Pluto. The accuracy to Pluto is now 6300 km (3-sigma), but 4200 km (300-sec arrival uncertainty) is needed for the on-board instruments to be sequenced properly. The trajectory correction maneuver (TCM), 21 days before flyby, requires accurate ground measurements of Pluto in order to obtain the 300-sec window. Three recent observations of ALMA demonstrate the importance of these data. To complete the ALMA parallax measurements, we propose observations in July and October 2014. With the ~1 km ALMA array that is available, the accuracy should decrease to 3 mas (rms). With ground optical observations, the final TCM should have the accuracy to place the spacecraft within the necessary arrival window. The ALMA experiment did not obtain time through a cycle-1 proposal or a DDT proposal, but was considered as a valid astrometric test project under CSV. It is now appropriate to submit the remainder of the parallax observation as a DDT observation so it can be archived as a scientific experiment with the data publicly available as soon as possible. | Solar system - Comets | Solar system | 2016-08-10T19:03:31.000 |
| 539 | 2019.1.01337.S | 62 | Identifying Dust Settling in the Early Stages of Disks | The timescale for dust settling to occur and how it evolves remains highly debated. Uncertain constraints in dust settling hinders progress for understanding planet formation and disk evolution. This is largely due to the lack of observations that can resolve the dust scale heights in the early stages. Our previous VANDAM Orion ALMA survey discovered an unprecedented number of Class 0/I edge-on disks. We propose follow up observations of 0.02" resolution towards six edge-on sources in order to resolve the vertical height of the disks. In combination with existing data on Class II disks, the measurements of dust heights will constrain when dust settling may happen. If dust settling does not occur in the early stages, then planet formation must be limited mostly to the Class II phase or later. If dust settling does occur, then planets may develop even in the earliest phases of disks. | Disks around low-mass stars | Disks and planet formation | 2022-11-30T15:19:48.000 |
| 540 | 2015.1.01600.S | 130 | ALMA Survey of Gas Evolution in Herbig Ae Population | Giant planets are more frequently found around stars more massive than the Sun. And yet, our current knowledge of planet formation around intermediate-mass stars is built upon mid- and near-IR surveys, probing the distribution (or lack) of material in the terrestrial planet formation zone. Observations probing the outer disc regions where giant planets are thought to form, are heterogeneous, biased towards the brightest discs, they mainly probe the dust and some probe the gas in the disc surface. Our proposal aims to constrain the largest missing piece of the puzzle - the gas in the disc midplane. Our proposed CO isotope observations are designed to systematically compare the midplane gas densities in the unfrozen disc midplanes (up to 100 AU) in a large sample of intermediate mass Herbig Ae stars covering the full range of observed disc properties. We will look for correlations between the gas density in the giant planet formation zone and a variety of tracers of both the inner and the outer disc, to be used as a beacon for the development of gas dispersal theory in these stars. | Disks around high-mass stars | Disks and planet formation | 2017-07-14T14:07:43.000 |
| 541 | 2023.1.01573.S | 0 | SiO in the direction of filamentary structure in the diffuse ISM | The formation of molecular gas in the diffuse ISM is the first step of molecular cloud formation. Recent work has suggested that shocks play a crucial role in this process. We propose a survey to observe the shock tracer SiO in absorption toward 7 background sources behind a diffuse cloud complex with prominent filamentary structure, roughly doubling the sample of diffuse sightlines observed in SiO. We will measure SiO abundances (X_SiO) and linewidths close to the atomic-to-molecular transition to test for the role of shocks in the formation of diffuse molecular gas. SiO linewidths will constrain shock velocities and shock origins. These measurements will also provide useful statistical tests of whether the incidence and abundance of SiO are higher in the direction of filaments, assessing recent claims that X_SiO measured in quiescent environments depends on the history of the gas and that SiO may not be produced uniquely in shocks. Measurements of X_SiO in diffuse environments will also constrain the quiescent SiO abundance, which will update decades-old values and help test the reliability of X_SiO as a shock diagnostic in denser environments. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-08-05T22:19:55.000 |
| 542 | 2019.1.01491.S | 10 | Constraining the nitrogen abundance in a bright z=7 galaxy | The origin of nitrogen is an issue under debate even in the local Universe. Although much less information is available in the z>2 Universe, an enhanced N/O abundance at a sub-solar metallicity has been inferred at z~2, suggesting an unexpected high efficiency in the nitrogen enrichment. Here we propose an exploration program to open a new window on the nitrogen enrichment history in the earliest possible Universe. The target galaxy is a very bright z=7.1 Lyman break galaxy (LBG) from which we have detected the [OIII] 88 micron line, the [CII] 158 micron line and the dust continuum. We will observe the [NII] 122 micron line of this galaxy. If the galaxy has an enhanced N/O ratio as found in z~2 LBGs, we can detect the [NII] line at a 6-sigma significance. Therefore, we can prove the enhanced N/O ratio at the epoch 700 Myr after the Big Bang. Since [OIII] and [CII] information is already in hand, the [NII] data will allow us to break degeneracy between the ionization parameter and the elemental abundance with a detailed photoionization modeling. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2021-03-13T11:43:12.000 |
| 543 | 2023.1.00740.S | 0 | Exploring New 183 GHz Megamasers in Seyfert 2 Galaxies | The exquisite sensitivity of ALMA in Band 5 has invigorated interest in identifying and studying new extragalactic water vapor megamasers at 183 GHz. The recent study by Pesce et al. (2023) demonstrates that 183 GHz megamasers can be commonly detected in galaxies already known to host 22 GHz megamaser disks. In this proposal, we seek to discover new megamaser galaxies - i.e. not previously detected at 22 GHz - by their 183 GHz emission. We have selected a set of 38 Sy 2 galaxies best suited for this initial study based on their distance, location on the sky, and visual magnitude. The discovery of new 183 GHz megamasers from this proposal will provide an immediate estimate of the ubiquity of this promising maser transition, identify new galaxies for supermassive black hole (SMBH) mass measurements using ALMA, and motivate the development of future VLBI facilities for Band 5 observations. ALMA will thereby pioneer the use of the 183 GHz line as a new tool to investigate the physical conditions and geometries of accretion disks, probe SMBHs in active galaxies, and improve future geometric measurements of the Hubble Constant based on the megamaser method. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2025-07-19T23:30:10.000 |
| 544 | 2018.1.01647.S | 26 | Origin of Striking Difference of Spectral Line Richness in Intermediate-Mass Binary | 'How are the binary systems formed?" is a fundamental question of star formation studies to be adressed. Recently, we have found a striking difference in molecular line richness between two intermediate protostars NGC 2264 CMM3A and CMM3B, consisting a binary system. CMM3A is rich in complex organic molecules, indicating a sign of a hot core, while CMM3B is deficient in these molecules. This difference would originate from (1) different masses, (2) different evolutionary stages, and/or (3) different opacity of dust continuum emission of the two protostars. To assess these possibilities, we here propose molecular-line and continuum observations toward CMM3 at an angular resolution observation of 0.08" (60 au). By making use of a kinematic model of infalling-rotating envelope, we will evaluate protostellar masses to test the possibility (1). We will investigate the spectral indicies, rotation temperatures, and chemical compositions of these two sources to assess the possibility (2) and (3). The closer look at the physical/chemical structure of CMM3A/B will give a new insight of the binary formation process. | Intermediate-mass star formation, Astrochemistry | ISM and star formation | 2021-01-26T03:23:22.000 |
| 545 | 2018.1.00200.S | 3 | The Magnetic Field of VLA 1623 | We propose Band 6 polarization observations of the Class 0 system VLA 1623 at 0.6 arcsec resolution to capture the magnetic field morphology in the inner envelope of this source. Higher resolution Band 6 and Band 7 polarization observations of this source identify azimuthal dust polarization toward the large (180 au) Keplerian disk around VLA 1623-A. This azimuthal polarization is inconsistent with a toroidal magnetic field, which is expected for a rotating system. Instead, the observations appear conistent with a static, hourglass-shaped magnetic field morphology. The proposed lower-resolution observations are necessary to trace the magnetic field structure on scales beyond the Keplerian disk, where the effects of rotation are negligible. With these observations, we will characterize the magnetic field morphology of this system and determine whether or not the field has become decoupled from the gas due to non-ideal MHD processes. These observations are a first step in understanding the role of magnetic fields in protostellar systems. | Low-mass star formation | ISM and star formation | 2020-10-30T19:59:20.000 |
| 546 | 2017.1.01632.S | 32 | Gravity vs B-field in massive-star forming clouds: Who is in the driving seat? | The details of what physical processes (between turbulence, gravity, or magnetic field) regulates the mass transfer from the large scales of clouds and filaments onto the small scales of clumps and cores is still highly debated. The origin of such a debate resides in our (past) inability to track the magnetic (B) field properties over such a large range of scales and densities that are involved in the star formation process. Here, we propose to use ALMA to map, on a few thousand AU scale, the B-field morphology and gas velocity field towards the massive-star forming infrared dark cloud G34. Combined with our large-scale study of the region, these new observations will provide, for the first time, a complete picture of energy balance in a massive-star forming cloud. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-06-06T18:00:02.000 |
| 547 | 2019.1.00532.S | 7 | Accretion kinematics in the warped cavity of DoAr44 | Warps have often been invoked to explain disk properties, but well characterized examples are important for warp physics and their role in disk evolution. Optical/IR images of transition disks (TDs) have revealed deep decrements in the rings of HAeBes HD142527 and HD100453, that can be interpreted as shadowing from sharply tilted inner disks. We have recently reported similar dips in SPHERE+IRDIS differential polarized imaging (DPI) of TTauri DoAr44. In this case the shape of the decrements can be approximately accounted for with an inner disk tilt of ~30+-5deg. ALMA observations at 30mas in 12CO(3-2) and HCO+(4-3) will test this geometry with the observation of the warped and potentially infalling gas kinematics. The Band7 continuum will also measure the location and depth of the expected temperature drop in the shadowed dust, and hence constrain the mass of the outer disk via a novel method, based on a comparison with the expected cooling timescale. | Disks around low-mass stars | Disks and planet formation | 2022-06-08T00:00:00.000 |
| 548 | 2019.1.00516.S | 2 | Heating Models of the Quiet-Sun Solar Chromosphere | We request single-pointing ALMA observations of a quiet Sun region at Bands 3 and 6 in order to test heating mechanisms for the solar chromosphere, and to further constrain state-of-the-art numerical models. We have simulated the expected behavior of ALMA quiet-Sun images using the Bifrost code, which shows (magneto-)acoustic waves propagating upwards from the photosphere and forming shocks in the middle chromosphere. Such shocks would dissipate energy in these layers, thus providing a heating mechanism. We request Band 3 and 6 observations at the highest available spatial resolution to both look for the oscillations themselves, and to look for transient bright features indicative of shocks. The simulations also predict the temperature range that ALMA should observe, differing greatly at Bands 3 and 6. Comparison of the observations with the simulations will both test chromospheric heating models and help to identify physics currently missing from the simulations. | The Sun | Sun | 2021-08-14T00:00:00.000 |
| 549 | 2019.1.00738.S | 14 | Resolving dust substructures in mm-faint protoplanetary disks | ALMA surveys at high angular resolution show that substructures in the continuum intensity profile of bright and large protoplanetary disks seem to be ubiquitous. However, it is still not clear whether this is the case for the large majority of protoplanetary disks, which possess very compact (<15 AU) continuum emission at mm wavelengths. Observations that resolve these small disks and assess the amount of substructure in their dust content are still lacking. This is due two main reasons: an implicit bias in the selection criterion used in the present high angular resolution surveys, which targeted very bright objects, and the fact that resolving substructures in mm-faint objects is challenging due to their compact radial extent. We propose to image 5 mm-faint disks in the well studied Lupus star forming region at the maximum angular resolution that ALMA can provide today (16 mas, 1.2 AU in radius in Lupus) to characterise the level of substructures in compact sources, which represent well the bulk of the protoplanetary disk population. | Disks around low-mass stars | Disks and planet formation | 2022-11-04T00:00:00.000 |
| 550 | 2022.1.01307.S | 33 | Looking for Diffuse Gas in Tidal Dwarf Galaxies | One of ALMA's main goals is to uncover the physics of star formation - a key process in astrophysics which is still poorly understood. Recent studies of the molecular medium in nearby galaxies demonstrate that the molecular gas can exist in both a compact and a diffuse phase, which are believed to have different properties regarding star formation efficiency (SFE = SFR/MH2). In this context, we aim to use molecular gas observations to study the structure of the molecular medium and the behaviour of the SFE in a sample of tidal dwarf galaxies (TDGs). TDGs are newborn galaxies at z=0 that are forming within collisional debris, so they offer the unique opportunity to study the conversion from atomic gas, to diffuse molecular gas, to giant molecular clouds during the early phases of a galaxy's lifetime. We propose to do CO(1-0) observations using ACA + TP in a sample of three TDGs that already possess single-dish and 12m array CO detections. These observations will allow us to analyse the diffuse molecular gas fraction (f_dif) of the sample and put into a wider context the results obtained for the TDG J1023+1952, where a very high f_dif (80%-90%) was found. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-04-04T18:54:20.000 |
| 551 | 2013.1.01034.S | 6 | Tracing the Origins of Nitrogen Bearing Organics Toward Orion KL | A comprehensive analysis of a broadband 1.2 THz wide spectral survey of the Orion Kleinmann-Low nebula (Orion KL) has shown that nitrogen bearing complex organics trace systematically hotter gas than O-bearing organics toward this source. The origin of this O/N dichotomy remains a mystery. If complex molecules originate from grain surfaces, N-bearing species may be more difficult to remove from grain surfaces than O-bearing organics. Theoretical studies, however, have shown that hot (T=300 K) gas phase chemistry can produce high abundances of N-bearing organics while suppressing the formation of O-bearing complex molecules. We propose here to map, in exquisite detail, the temperature structure and D/H ratio of the complex N-bearing organic methyl cyanide (CH3CN) toward the Orion KL hot core. If gas phase formation routes are significant at high temperatures, we will observe a decreasing gradient in the D/H ratio of CH3CN with increasing kinetic temperature. The proposed observations will shed light on the origin of all complex N-bearing organics in the interstellar medium. | High-mass star formation, Astrochemistry | ISM and star formation | 2016-03-23T15:59:12.000 |
| 552 | 2018.1.00775.S | 8 | The remarkable molecular jet from IRAS 04166 | The molecular outflow from IRAS 04166 stands out among the outflows from the youngest protostars. It presents a remarkably symmetric geometry consisting of a pair of jets and two opposed conical shells. These properties make it an ideal laboratory to confront outflow models that favor jets and wide-angle winds. In Cycle 1 we mapped the velocity structure of two peaks of the IRAS 04166 jet. We found that the gas in the peaks is expanding laterally away from the jet axis, as predicted for internal shocks in a pulsating jet. In this proposal we aim to map the inner part of the jet, which contains five more pairs of shocks. With these new observations, we will reconstruct the complete history of the expanding shocks and investigate the origin of the jet pulsation. We will also estimate the amount of momentum transferred sideways from the jet to the outflow shells, which is a potential mechanism by which a collimated jet can drive a broader molecular outflow. This proposal is an updated version of proposal 2017.1.00014.S, which was rated C but has not been observed. We have taken in account the comments from the review panel. | Outflows, jets and ionized winds | ISM and star formation | 2022-10-25T03:08:36.000 |
| 553 | 2023.1.01253.S | 6 | A sharp view of the giant molecular clouds in a remarkable redshift 2.58 spiral galaxy | During cosmic noon, z~1-3, main sequence (MS) galaxies build up a large fraction of their stellar mass. Characterised by large gas fractions, their disks appear highly unstable and turbulent, leading to the formation of massive UV-bright stellar clumps. The combination of deep HST observations, complemented now with JWST, of strongly lensed clumpy galaxies have allowed to resolve these giant structures into tens of parsec star clusters with stellar masses between 10^6-10^8 Msun. To determine the nature of the giant molecular clouds (GMCs) where the UV clumps form, CO observations at sub-hundred parsecs are required. We propose high-sensitivity (gas mass>=10^7Msun) and resolution (0.08"~35pc) ALMA observations to resolve the CO(4-3) emission in a remarkable lensed clumpy galaxy at z=2.58, showing a spiral morphology and hosting 40 UV clumps. We aim to detect the GMCs leading to the formation of these numerous UV clumps and determine their mass, density, turbulence, pressure, star formation efficiency. Together with GMC studies previously performed in 2 MS galaxies at z=1, we will probe the evolution of GMC properties in different and rapidly evolving ISM conditions over cosmic time. | Galaxy structure & evolution | Galaxy evolution | 2024-10-20T19:45:56.000 |
| 554 | 2017.1.00985.V | 0 | Understanding jet formation and testing the binary SMBH system in OJ287 | We propose 3 mm GMVA+ALMA observations of the BL Lac object OJ287, one of the best candidates for hosting a binary SMBH and to study jet formation in magnetically dominated AGN. The improvement in the north-south resolution and sensitivity provided by ALMA, and the comparison with quasi-simultaneous, resolution-matched 1.3 cm RadioAstron and 1 mm EHT+ALMA images will allow us to perform Faraday rotation synthesis and opacity analysis with an angular resolution of 30-40 microarseconds, a ~10-fold improvement with respect to previous studies. Comparison with a similar campaign performed in spring 2017 will allow us, for the first time, to study the magnetic field, Faraday screen, accretion rate, jet ridge line, and particle energy distribution evolution at scales not probed before in a blazar jet. This will be used to test the applicability of magnetically driven jet formation models and to test the binary SMBH scenario by comparing predictions from different models. This is the 3 mm VLBI proposal part, which will complement approved 22 GHz space VLBI observations and in parallel proposed 230 GHz EHT observations in March/April 2018. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2020-11-20T00:00:00.000 |
| 555 | 2013.1.00764.S | 32 | Probing Accretion Flow Dynamics of Sgr A* on Scales from 1 to 1000 Schwarzschild Radii with ALMA Polarimetry | Sagittarius~A* is the nearest supermassive black hole and presents an exceptional opportunity for detailed examination of accretion physics. The polarimetric capabilities of ALMA are poised to transform our understanding of Sgr A* by uncovering variations associated with the accretion environment and dynamics. Whereas previous efforts have constrained variability in rotation measure over a timescale of years, ALMA has the potential to uncover changes in both the intrinsic polarization and the subsequent Faraday rotation on timescales of minutes. With the impending impact of the G2 gas cloud, the potential information from both short and long timescale variations is especially rich, and can enable dynamical tomography of the accretion flow. Finally, a single long pointing with ALMA can resolve the polarimetric signature of intra-hour variations seen at submillimeter wavelengths, suggestive of quasi-periodic orbits and associated with dynamical activity of the accretion flow on event-horizon scales. These signatures can probe the relative contributions of coherent and turbulent magnetic structures in the innermost accretion flow. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-06-23T18:48:19.000 |
| 556 | 2013.1.01151.S | 25 | Tracing the Chemical Evolution of Active Galaxies | To trace the chemical evolution of galaxies, a detailed knowledge of abundance patterns is fundamental. Isotope ratios play a key role in such studies and are, almost exclusively, a domain of radio and (sub-)mm astronomy. So far, the extragalactic space beyond the Magellanic Clouds is almost unexplored. What ratios can be found, when observing objects beyond the Local Group, which drastically differ from those in the Miliky Way and the LMC? Is the Galaxy typical for its class or are its isotopic properties exceptional? And what does this imply for its evolutionary track? Such questions can only be tackled when using the extreme sensitivity of ALMA. Here we propose to measure carbon (and oxygeni) isotope ratios in three outstanding star forming galaxies beyond the Local Group. | Spiral galaxies, Merging and interacting galaxies | Local Universe | 2016-03-05T19:02:17.000 |
| 557 | 2021.1.01142.S | 108 | The cold molecular medium across Enormous Ly-alpha Nebulae: studying clustered galaxy formation with ALMA+ACA | Massive galaxies at high-z are known to co-evolve with their circum-galactic medium (CGM), typically detected in Ly-alpha. However, a direct link between this CGM and the stellar growth of massive galaxies remains ambiguous, as we have yet to identify gas-phase that can fuel widespread star-formation, namely cold molecular gas at 10-100 K. We propose to use ALMA plus ACA to study the cold molecular medium on large scales across 5 Enormous Ly-alpha Nebulae at z~2. Contrary to conventional samples of Ly-alpha nebulae, which are typically detected around massive radio galaxies or type-I QSOs, our sample consists of nebulae surrounding densely clustered galaxies. We will simultaneously observe the low-density gas tracer CI 3P0-3P1 and the high-density tracer CO(4-3), to obtain the mass, extent, composition and physical properties of the multi-phase CGM. In addition, we will perform a commensal continuum search for the Sunyaev-Zeldovich Effect from the cluster or from winds that may enrich the CGM. Studying the multi-phase CGM with sensitive surface-brightness ALMA+ACA observations opens an exciting new window for investigating the early formation of massive galaxies and clusters. | Lyman Alpha Emitters/Blobs (LAE/LAB), Galaxy Clusters | Galaxy evolution | 2022-12-17T20:59:11.000 |
| 558 | 2018.1.01879.S | 4 | Advanced determination of the Sun's temperature stratification | The Suns chromosphere, which is effectively probed with ALMA, is a spatially intermittent and highly dynamic phenomenon. In-depth studies of the chromosphere's dynamic nature could be helped by a detailed quantitative knowledge of the average properties of the chromospheric plasma, which would serve as a reference. The average temperature stratification of the solar atmosphere and the resulting centre-to-limb variation at various wavelengths have been determined before but often neglected spatial variations on small spatial (and temporal) scales that can have an important impact on the derived average properties. Likewise, the average formation heights of key diagnostics (like the mm continua) should revised in order to ensure meaningful interpretation of solar observations. We propose mosaic observations of the Sun in Band 3 and 6. The aim is to construct more precise reference models of the Sun and corresponding continuum formation heights for Band 3 and 6 with the help of a novel ALMA data inversion code. | The Sun | Sun | 2020-10-29T07:36:48.000 |
| 559 | 2017.1.01361.S | 14 | A systematic exploration of the hybrid disk phenomenon around young A-type main-sequence stars | Based on ALMA observations, our group recently defined a new class of circumstellar disks. "Hybrid disks" encircle 10-50 Myr old A-type stars, their tenuous dust content resembles debris disks, while their massive gas component is leftover protoplanetary material. So far only four hybrid disks are confirmed, but there are several candidate systems where the lack of information on whether 12CO is optically thick or thin introduces a factor of 100x uncertainty in the gas mass determination. Here we propose to observe 13CO and C18O isotopologues in four hybrid disk candidates with ALMA, in order to decide whether they are hybrid disks or pure secondary disks. We will (1) measure the dust and gas mass of the disks; (2) determine the morphology of dust and gas; (3) identify the origin of gas; and (4) characterize the new class of hybrid disks. The proposed targets will complete a volume-limited sample of massive debris disks around young A-type stars. Our observations have the potential to double the known hybrid disk population, enabling us to establish the incidence of hybrid disks more precisely than ever, which may have consequences on the general disk evolution paradigm. | Debris disks | Disks and planet formation | 2019-09-26T16:53:33.000 |
| 560 | 2021.1.01208.T | 5 | Probing Relativistic Jets through Sub-mm Timing Observations of X-ray Binaries | Black hole X-ray binaries (BHXBs) are accreting objects that launch powerful relativistic jets. These binary systems evolve through bright outbursts on rapid timescales of days to months, and in turn allow for real-time probes of jet phenomena. In recent years, time-domain observations studying correlated multi-wavelength fast variability in BHXBs has been shown to be a powerful tool that allows us to address key open questions in black hole jet physics. We propose 11.2 hrs of Band 6 ALMA ToO observations (8 x [1-hr on source + 25 min overheads/calibration]) to obtain high time resolution, sub-mm observations of the next bright out-bursting BHXB. These ALMA data will be combined with simultaneous multi-wavelength data (radio, mm, infrared, optical, far-UV, and X-ray) to carry out a comprehensive multi-band spectral timing study. With these data, we will measure jet speed, geometry, and energetics, gain an understanding of how the jet is powered by the accretion flow and its relationship to accretion disc winds, as well as, for the first time, perform these studies as a function of accretion rate during an outburst. | Black holes, Transients | Stars and stellar evolution | 2023-10-03T10:46:24.000 |
| 561 | 2021.1.00783.S | 14 | The Molecular Wind of NGC4945 | We propose to observe the molecular wind of the very nearby starburst/Seyfert 2 galaxy NGC4945. The wind is clearly detected in archival CO (3-2) observations, but these lack the extent or velocity coverage to probe the whole structure. Our proposed deep mosaic in CO (2-1) will improve over an order of magnitude in surface brightness sensitivity and cover the whole ionized outflow cones, allowing us to determine the full extent, mass, and mass outflow rate of the cool outflow. Resolving the molecular wind and tracking its full extent and acceleration is crucial to constrain the poorly understood physics of superwinds, but is only possible in the closest winds, and NGC4945 is one of only a handful of such galaxies. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-06-07T11:21:50.000 |
| 562 | 2019.2.00133.S | 14 | Kinematic mapping of the filamentary high-mass star formation scenario | Leveraging our ALMA-IMF large program observations (at ~1" / ~2000 AU resolution) of the center of the G353.41 proto-cluster, here we propose complementary ACA observations of the larger (3.5 pc x 1.8 pc) quiescent filament environment of G353. These observations will therefore complement and complete the ALMA-IMF science, specifically by probing two radically different star formation (SF) environments: the mass reservoir in the quiescent filament, and the cluster that is forming on the end of the filament. The filament-to-clump-scale kinematics, which is missing in the ALMA-IMF observations, will be revealed by our band 3 observations of N2H+, HC3N, CH3CCH, and HNC. These observations therefore set the ALMA-IMF context by directly probing the relation of the protocluster to the larger scale filamentary mass reservoir, and measuring multi-scale kinematics on filament-to-core scales. We thus expect to gain insights onto how mass assembly of dense cores proceeds in the filamentary struture by comparing the observations with the two competing high-mass SF models, i.e., filament-fed versus core-fed accretion models. | High-mass star formation | ISM and star formation | 2022-10-22T16:06:18.000 |
| 563 | 2013.1.01057.S | 29 | Band 3/4 spectral scan in the central filament of merging LIRG VV114 | Investigating local merger-driven starbursts is important to understand physical processes involved in the formation and evolution of galaxies. Our cycle 0 observations toward mid-stage merger VV114 revealed that the merger-induced filamentary structure (including the AGN, starbursts, and shock-induced overlap) shows the chemical differences at each region for the first time, while our detected lines could not fully explain driven physics of such molecular diversity. We thus propose 8.3 hours observations of mid-stage IR-bright merger VV114 through well-studied 84 - 111 and 127 - 154 GHz to provide comprehensive picture of chemical diversity among AGN, starburst, and shocked regions in the dense gas filament simultaneously. Using band 3 and 4, we can detect 33 molecular lines and classify them three chemical types (AGN-dominated, SB-dominated, and shock-dominated) by mapping them with 1".0 resolution enough to resolve specific regions. Moreover, we will constrain the temperatures and column densities of given molecules easily by rotation diagram, and compare their chemical/physical conditions with other extragalactic molecular line survey to explain driven chemistry of VV114. | Merging and interacting galaxies, Galaxy chemistry | Galaxy evolution | 2016-08-25T02:54:15.000 |
| 564 | 2023.1.00391.S | 0 | Validating [CII]-SFR Relation in a z=8.22 Galaxy Group | From the local Universe to the Epoch of Reionization, [CII] 158um line luminosity has been found to broadly trace the star-formation rate (SFR) of galaxies. However, our understanding of [CII] becomes much more uncertain at higher redshifts. Specifically, at z>8, [CII] line was only robustly detected in a few lensed galaxies because of the difficulty in redshift confirmation before the JWST. We propose a Band-5 single-pointing [CII] observation of a three-galaxy group at z=8.22, aiming to double the number of [CII] detections at z>8 with the most efficient ALMA setup. These galaxies were selected with deep JWST/NIRCam imaging, and their redshifts have been confirmed with [OIII] 5007-line spectroscopy. We will obtain the first [CII] detection from unlensed galaxies at z>8, validating the [CII]-SFR relation in a galaxy overdensity at unprecedentedly high redshifts. This proposal will also detect or place strong constraints on [CII]-traced outflow, dust-obscured star formation and the necessity of very top-heavy IMF from luminous z>8 galaxies, characterizing the physics behind star formation, dust production and feedback during the first 600 Myr of the cosmic history. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2025-09-24T17:00:35.000 |
| 565 | 2018.1.01652.T | 38 | The properties of compact-object mergers detected by LIGO and VIRGO | With the discovery of the binary neutron star merger gravitational-wave (GW) source GW170817, and its electromagnetic counterpart, the era of GW+EM multi-messenger astronomy has truly begun. The combined power of the LIGO and the VIRGO GW detectors led to a rapid localisation in the range of several dozen square degrees, combined with the distance information as a third dimension. This allowed the discovery of a kilonova (KN) associated with the merger event, and thereby a precise localisation and distance measurement. While the optical emission traces the radioactive merger ejecta powering the KN, emission in the radio domain traces relativistic ejecta associated with the accompanying gamma-ray burst (GRB). We propose to follow up compact-object mergers with ALMA. Our goals are to 1) determine the range of electromagnetic properties seen in compact-object mergers, 2) establish how properties of the electromagnetic counterparts depend on the system parameters and viewing angle, which can also be important to break degeneracies in the GW analysis, 3) measure the structure of jets to demonstrate how mergers create short GRBs, and 4) study the environment of the GW source. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2020-12-31T11:40:32.000 |
| 566 | 2013.1.00786.S | 7 | Using [CI] to determine the distribution and heating mechnanism of H2 in a z=4.8 star-forming disk | In cycle 0, we identified a large, 8 kpc rotating [CII] disk in a strongly star-forming galaxy at z=4.8, ALESS73.1. Its [CII] emission extends well beyond the host galaxy, but the gas it traces (atomic or molecular) is unknown. Here we propose matched-resolution imaging of the [CI] (1-0) and (2-1) lines (and simultaneous high-J 12CO and 13CO) to: a) test a new method to determine the full extent and mass of its H_2 gas disk, its velocity field, and enclosed dynamical mass, b) look for potentially serious biases of the very luminous [CII] line in tracing the H_2 gas in galaxies, and c) determine if FUV photons from its starburst can maintain the thermal state of the dense H2 gas The answer to the latter directly impacts on the initial conditions of star-formation and whether they can be dramatically reset in such disks Thanks to its fortuitous redshift, allowing both [CI] lines, [CII] and high-J CO lines to be observed with ALMA, its unlensed and isolated nature, ALESS73.1 is the ideal target for this complete and spatially resolved study of the molecular and atomic ISM tracers. This [CI]-based H2-tracing method can be applied throughout 0 | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-11-12T10:22:32.000 |
| 567 | 2022.1.01015.S | 34 | Different fragementation modes of the Nessie filament towards massive clumps | Filamentary molecular clouds are ubiquitous in the interstellar medium. Massive filaments seen throughout the Galaxy typically host one or more massive clumps, which eventually will form stars. However, their role in accumulating mass in the sites of active star formation is presently poorly known. Fragmentation, the process of forming a series of dense clumps, is commonly seen along filaments, but the physical conditions defining the fragmentation pattern remain unknown. We select five regions with identified partially massive, star-forming clumps within the massive Nessie filamentary cloud to address this issue. We propose to observe the spine of these linear structures and the surrounding medium with the ACA to map their velocity field, looking for ordered mass flows along and across the filament. The large-scale environments of the regions represent two typical scenarios for star-forming filaments, quiescent and shocked. Characterising these conditions and studying the resulting gas motions will help to reveal the physical processes important in the early phases of star formation. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2024-10-25T20:44:57.000 |
| 568 | 2018.1.00461.S | 21 | Determining the Dynamical Origin of the Disk Structure Around HD 53143 | HD 53143 offers a unique opportunity to study the architecture of a planetary system. Much like how the Solar System's complex distribution of asteroids, comets, and KBOs informs our dynamical history, the structure of debris around HD 53143 appears complex and informative. This star hosts a bright inner disk and a faint outer disk and is oriented face-on, making it simple to identify disk structures. The outer disk is home to two intriguing ``clumps" of dust that have unknown dynamical origins and are possibly due to an unseen planet. The HD 53143 debris disk is the only face-on disk with signs of a planet-induced resonant dust structure observed in scattered light. We propose to observe the inner and outer disks of HD 53143 with ALMA to measure the spatial distribution of mm-sized grains, which are a proxy for the parent planetesimals. These observations will reveal the dynamical architecture of the system, allowing us to determine the origin of the asymmetric clumps and constrain the composition of the dust grains. Our proposed ALMA observations will allow us to differentiate between three possible dynamical scenarios that could explain the presence of the observed clumps. | Debris disks, Exo-planets | Disks and planet formation | 2020-08-09T22:11:22.000 |
| 569 | 2013.1.00020.S | 31 | Hydrides as diagnostic tools for the z=0.89 absorption toward PKS 1830-211 | The z=0.89 molecular absorber toward the quasar PKS 1830-211 is the best known source for obtaining very detailed information on the physical and chemical state of the molecular gas in the disk of a galaxy with a look-back time of more than half the age of the Universe. In ALMA Cycle 0, we observed strong absorption lines of most common interstellar molecules, revealing the absorption along the two lines of sight with unprecedented detail. Now, we propose to focus on hydrides, the key molecules at the root of the interstellar gas-phase chemistry, and use them as diagnostics of the physico-chemical gas properties. We will investigate the nature of the absorbing gas, the cosmic ray ionization state of hydrogen, the local turbulence, the hydride chemistry, and the cosmological enrichment of the interstellar medium. | Spiral galaxies, Galaxy chemistry | Local Universe | 2016-07-06T16:42:08.000 |
| 570 | 2016.1.01456.S | 21 | Dynamical Masses of a Taurus Low Mass Star and Brown Dwarf | With ALMA observations combining high spatial and spectral resolution, we propose to observe an exceptional binary system in Taurus with two gas disks that we detected and resolved with Cycle 1 data. The binary pair is composed of a very low mass primary with a mass near the stellar limit and a faint substellar companion with a mass that may be as low as 10Mjup. These mass estimates are derived from comparison of photometry and evolutionary models, and there is a critical need to obtain empirical calibration of the evolutionary models with dynamical mass estimates. By mapping the kinematics of the two disks with ALMA, we propose to measure the masses of each component of the system and provide a benchmark calibration of the evolutionary tracks at a much lower mass than was possible previously. The mass estimate from the Keplerian motion of the companion disk will determine whether the object is genuinely planetary in mass or is an obscured more massive object. In addition to the spectral line maps, these observations yield a sensitive continuum map, from which we will compare the gas and dust disk radii and investigate the possibility of the dust disk having a sharp outer edge. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2018-08-20T17:28:14.000 |
| 571 | 2017.1.00338.S | 24 | Resolving the controversy of the stellar IMF in SNELLS-1 using molecular gas dynamics | The stellar initial mass function (IMF) appears to be universal across the range of environments we are able to probe within our own Galaxy. In the early universe, and in other extragalactic environments, however, evidence for the non-universality of the stellar IMF is mounting, especially for the most massive early-type galaxies. Despite various converging lines of evidence for this variation, significant uncertainties and unresolved problems remain. We propose here a focused investigation of SNELLS-1, a nearby ETG which is strongly lensing a background star-forming object at z=1. This lens is part of a small sample of objects that should have a heavy IMFs according to the trends reported in the literature, but where the lensing mass is entirely inconsistent with this. With a short ALMA CO(2-1) observation we can accurately determine the mass profile of this object dynamically. Using these measurements we will determine the IMF normalisation through a highly-robust indepenent method, resolving this controversy and determining if the previous analyses were too simplistic, or if our understanding of what drives systematic variations in the IMF need to be revisited. | Early-type galaxies | Galaxy evolution | 2019-10-15T12:13:09.000 |
| 572 | 2017.1.01257.S | 26 | Unveiling Properties of the Cold Gas Disk/Torus within the Central 1 kpc of NGC 1275 | NGC1275 is a giant elliptical galaxy at the center of the Perseus cluster, which is the brightest X-ray cluster of galaxies. Contrary to other elliptical galaxies in a similar system such as M87, NGC1275 reserves a large amount of cold gas within ~1 kpc and reveals an existence of the warm H2 circumnuclear disk (CND) on the inner 50 pc. Thus, NGC1275 is the best target to study the cold gas properties in the CND, which provides a better understanding of gas accretion from the ICM to the SMBH. However, there is a missing link in the mass accretion between the outer kpc and the inner 50 pc scales because of the lack of mm observations to trace cold molecular species and dust with a high-angular resolution. Here we propose to observe the cold gas of NGC1275 at ~50 pc < R < 1 kpc using the CO(2-1) and HCO+(3-2) lines as well as the dust continuum emission with ~0.1" (or ~35 pc) beam. With this observation, we aim to uncover i) clumpy and filamentary structures in the accretion flow, ii) connection between the CND and large scale molecular filaments, iii) thickness of the CND, and iv) the location of the Fe-K\alpha lines, which is recently detected with the Hitomi satellite. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy groups and clusters | Active galaxies | 2019-03-20T00:00:00.000 |
| 573 | 2017.1.01066.T | 2 | THE EFFECTS OF BURST ACCRETION ON PHYSICAL AND CHEMICAL PROPERTIES OF PROTOPLANETARY DISKS | FU Orionis Objects (FUors) represent the burst phase of the episodic accretion process through protostellar disks, which is considered as the formation mechanism of low mass stars. Therefore, FUors provide an opportunity to study the dynamical evolution of disk structure during outburst. In addition, newly bursting FUors are excellent targets for the study of fresh sublimates, offering a unique and direct probe of the ice composition in the pre-burst (i.e. quiescent) phase. Therefore, in order to study the burst-accretion process and the effect of enhanced heating on disk composition and structure, we propose a ToO observation for a FUor newly confirmed by one of a variety of transient surveys such as Palomar Transient Factory, ASAS-SN, and our JCMT/SCUBA2 survey for sub-mm variability. (The co-Is, Gregory Herczeg and Doug Johnstone are leading the JCMT large program on transient YSOs.) Our proposed observations include lines of CH3OH, 13CH3OH, C17O, H13CO+, HDCO, HDO, CCH, SiO, SO, SO2, and various organic molecules at band 7 with a velocity resolution of 0.2 km/s and a spatial resolution of ~0.15". | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-03-08T17:48:07.000 |
| 574 | 2021.1.01047.S | 29 | Formation of VLM stars and BD in Lambda Orionis Star Forming Region (LOSFR). ACA view of LDN1589 | Several projects have been conducted to search for pre- and proto-BDs in the Lambda Orionis Star Forming Region (LOSFR) to study key aspects of stellar and substellar formation. One of its dark clouds, B30, has been observed from optical to radio and their substellar objects have been studied. ALMA Band 7 data allowed to detect 3 pre-BDs candidates. Based on this, we focus on the present proposal on one of the youngest dark clouds of the LOSFR, LND1589, for which we have archival data from the optical to the mid-infrared, and submm data taken at 870um using APEX/LABOCA. We propose ACA Band 6 observations (along with an on-going APEX/ArTeMiS project) to: i) obtain spectral index information on sources detected in multiple projects to study grain growth and estimate their masses, ii) improve the selection function to identify candidates to be followed up with the 12m array, iii) build complete SEDs and estimate their Lbol and Tbol to derive their evolutionary stage, iv) model the radial profiles of the cores and compare them with those of low-mass stars, v) build a larger poll of pre/proto-substellar objects to put strong constraints on their proposed formation mechanisms. | Low-mass star formation | ISM and star formation | 2023-02-03T08:52:03.000 |
| 575 | 2019.1.00271.S | 11 | A very low-mass prestellar core in Taurus: investigation of brown dwarf formation | The formation scenario of brown dwarfs is still under debate. The difficulty in understanding the formation of brown dwarfs is related to the fact that there are no observational examples to investigate the initial conditions of brown dwarf formation. Our systematic survey of nearby low-mass star-forming regions using the ACA stand-alone mode in 1.2 mm continuum has identified a centrally concentrated starless condensation, MC5-N. The total mass is ~0.2-0.4 Mo, which is an order of magnitude smaller than typical prestellar cores. The ACA observation also revealed the possible substructures with the size scale of a few hundreds of au. In this observation, we will investigate whther the centaral density is high enough to gravitatinally collapse or not. In addtion, to this we will discuss the formation mechanism of very-low mass prestellar core by identifying the substructure/fragments for the first time. We propose ~1" (~140 au) scale observations toward MC5-N in Taurus. The dust continuum and molecular lines (e.g., N2H+, CO, and its isotopes) observations will constrain the formation mechanism of brown dwarf and its prestellar core. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2021-07-24T08:01:33.000 |
| 576 | 2022.1.01651.S | 18 | Highest Dynamic Range Spatiokinematic Mapping of an Infrared Dark Cloud | Infrared Dark Clouds (IRDCs) are the likely precursors of most star formation in our Galaxy and are thus crucial objects to characterize and understand. In particular, the relative importance of turbulence, magnetic fields and internal/external feedback remain poorly known. Here we propose ALMA 3mm observations of 13CO and C18O of a large ~10 field that will be combined with GBT-Argus data to yield the highest ever spatial dynamic range (~8 pc to 0.007 pc) ppv-cube of an IRDC (G38.95-00.47) to probe its molecular gas structure and kinematics. Kinematic methods of inferring B-field properties will be tested, including via comparison with ancillary SOFIA-HAWC+ polarimetric imaging data. We will also observe 12CO emission to trace protostellar outflows and study their influence on driving turbulence in the IRDC. Dedicated numerical simulations of molecular clouds will be developed and tested against the derived datasets, which will also be released to the community for general benchmarking of molecular cloud and star formation physics. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-04-15T20:30:33.000 |
| 577 | 2015.1.01352.S | 8 | Origin of the Relativistic Jet Power | Background: Understanding of the formation, acceleration and collimation mechanism of the relativistic jet is one of the long-standing issues for modern astrophysics. Goal of this Observation: With new ALMA capability of long baseline, we would like to resolve the core of M 87 into the core-jet structure at shorter millimeter wavelength for the first time and derive pure SED for the jet. Scientific Impact: We will plan to derive break frequency due to the synchrotron cooling, and estimate the magnetic field strength without assumption of the equipartition condition. Then, we plan to estimate the magnetic power at the jet base in order to test magnetized jet paradigm. Why ALMA Cycle 3?: Following our successful cycle-0 observations of ALMA, we would like to push forwards our SED analysis to the higher angular resolution and suppress the contaminations. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-01-14T20:56:55.000 |
| 578 | 2017.1.00065.S | 5 | CO-Dark Molecular Gas in the Extended Ultraviolet Disk of M83 Revealed by Dust Continuum Observations | The extended ultraviolet (XUV) disks that are present in 10% of nearby galaxies offer the opportunity to study the interstellar medium and star formation in extreme conditions with low average gas density and surprisingly abundant star formation. However, our progress in understanding these XUV disks has been halted by the difficulty of detecting molecular gas via CO emission. In particular, no highly significant (>5sigma) CO was detected in an ALMA map of the XUV disk of M83 (a field with LMC-like metallicity) when we expected to detect 20-30 molecular clouds with >17sigma. We hypothesize that CO is weaker than expected because the molecular clouds are dominated by CO-dark molecular hydrogen, due to the strong local FUV radiation field or the small size of the star forming clumps (and not due to metallicity). We propose Band 7 dust continuum observations of part of the same field that was observed in CO. With these data, we will discover the first dust concentrations associated with CO-dark molecular clouds in XUV disks. We will test whether the number and mass of the molecular clouds agree with our predictions and we will derive the CO-to-H2 conversion factor for the region. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2020-08-14T20:10:59.000 |
| 579 | 2016.1.00726.S | 18 | Characterizing the Physical Conditions of the Interstellar Medium in a Galaxy Triplet at z = 2.1 using [CI] | We propose atomic carbon [CI] (2-1) and [CI] (1-0) observations of a galaxy triplet at z=2.1, spectroscopically confirmed with HST/grism spectra and imaging. The system consists of 2 massive galaxies separated by only 5 kpc and hosting an X-ray AGN, with a starbursting dwarf companion 33 kpc away. These galaxies have 1-2 orders of magnitudes higher SFR surface densities than BzK galaxies like in local ULIRGs, but lurk right below the Herschel detection limit and have lower SFR than SMGs. The proposed observations will yield molecular gas temperature, density and mass measurements for 3 individual galaxies in 1 pointing within 5.6 h of Band 4 & 6 observations. Our aim is to bridge the gap in our understanding of the molecular gas excitation between the well-studied BzK galaxies, QSOs and SMGs, and infer the interstellar medium (ISM) evolution over the course of the galaxy interaction in this early cosmic epoch. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2018-08-04T08:44:08.000 |
| 580 | 2023.1.00835.S | 0 | Ultradeep [CII] observations of rotating gas disks at z=4.5 | The importance of dark matter (DM) in high-z galaxies is debated with key implications for cosmological models of galaxy formation. Rotation curves (RCs) are a prime tool to study DM in galaxies but must be traced out to large radii where DM dominates over baryons. [CII] observations in individual galaxies at z=4-5 revealed the existence of rotating gas disks and allowed measuring their inner baryon-dominated RCs (R<3-4 kpc), while stacking [CII] experiments discovered diffuse [CII] emission extending out to 15 kpc in diameter. We propose ultradeep [CII] observations at 1.5 kpc resolution in two galaxies at z=4.5 that have (1) rotating gas disks, (2) evidence for extended [CII] emission, and (3) incoming JWST imaging. Our goals are to (1) study the gas kinematics in the outer regions to disentangle rotation from possible inflows or outflows, (2) trace extended RCs to unambiguously probe the DM halos, (3) measure the gas velocity dispersion at large radii and study disk stability. Our pilot ultradeep ALMA observations can open the only possible window to trace extended RCs at z>4, which will be otherwise inaccessible even for future facilities like SKA in HI and the ELT in H-alpha. | Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 581 | 2018.1.00816.S | 35 | Massive molecular gas flows encasing radio bubbles in the Phoenix cluster | Powerful radio jets launched by a central supermassive black hole pump a substantial amount of energy into their host galaxies and cluster environment. This feedback from the central AGN is thought to suppress gas cooling and star formation at late times to regulate the growth of massive galaxies and cooling of their surrounding hot atmospheres. The Phoenix cluster at z=0.596 hosts an extreme example of this common mechanism in galaxy evolution. Our ALMA Cycle 2 observations of the central galaxy revealed 10 billion solar mass filaments of molecular gas, each 10-20 kpc long and drawn up around the peripheries of the inner radio bubbles inflated by the jet. Smooth velocity gradients and narrow line widths along each filament show that these are massive, ordered molecular gas flows around each bubble. We now propose observations of a higher order CO transition to study the excitation of the gas flows and distinguish two outflow scenarios and at higher spatial resolution to resolve the circumnuclear structure and discover the fate of the filaments. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2021-07-06T12:35:45.000 |
| 582 | 2015.1.00966.S | 9 | A Complete ALMA Portrait of Dust and Gas in Fomalhaut's Kuiper Belt | Among debris disks and exoplanetary systems, Fomalhaut stands out as a rare example where an exoplanet potentially crosses through the system's Kuiper Belt. Fomalhaut therefore represents a unique opportunity to directly observe an epoch of evolution that could correspond to the LHB in our solar system. Fomalhaut is also one of the closest exoplanetary systems, and its dust structures can be mapped in unprecedented detail. ALMA is ideally suited to create such a map because over the large Fomalhaut field it can identify substructure with repeatable fidelity over decade timescales. We propose creating a detailed portrait of the entire outer dust belt in Band 6 at 1.6" (12 AU) resolution that will test for substructure hinted by HST optical imaging. Moreover, the observations will test a new theory of grain collisional dynamics that predicts the belt's apocenter should have excess millimeter emission. Finally, the ALMA data will provide an unparalleled probe for CO in the outer belt. This portrait of the system in Cycle 3 will serve as an essential baseline for comparison to observations decades in the future so that we may witness the evolution of the system in real time. | Debris disks, Exo-planets | Disks and planet formation | 2017-05-11T21:13:08.000 |
| 583 | 2013.1.01119.S | 4 | Unveiling the nature of the reddest submillimeter sources in lensing cluster fields | We propose to unveil the nature of very red submm sources discovered in four out of 10 Herschel Lensing Survey (HLS) clusters followed up at 870microns with LABOCA. Undetected in the Herschel bands, these sources may be the first dusty galaxies with moderate intrinsic luminosities (LFIR<10^12 Lsol) detected at very high redshifts (z>5) or low luminosity cold dusty galaxies with Td<25K. Measuring their luminosities and redshifts will put important constraints on the density of normal dusty star forming galaxies beyond z=4 and on the fraction of dusty star formation occuring in cold galaxies at lower redshift. Mapping these sources at 1.1mm with ALMA to a sensitivity of 0.1mJy will allow us to detect them with S/N>10 as well as any other lensed galaxy with an intrinsic LFIR>10^11Lsol up to z=10, and enable us to unambiguously identify their counterparts, estimate their redshift, and constrain their FIR luminosity and dust temperature. The core of massive galaxy clusters are the site of many astrophysical processes, and the data would further serve a number of ancillary purposes that we discuss in the text. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2016-07-31T10:13:29.000 |
| 584 | 2021.1.00935.S | 6 | The z=7 SPT0311 protocluster: cluster membership and dynamics from line observations | From the SPT 2500deg^2 survey, SPT0311-58 has been identified as a candidate z=7 protocluster. The protocluster core exhibits spatially extended LABOCA contours, that resolve into multiple sources with initial ALMA followup. There is a large overdensity of LABOCA sources with red Herschel-SPIRE colours in the surrounding field, two of which have been identified by ALMA as belonging to the structure. The proposal leverages extensive results and archival datasets, ongoing HST programs, and approved JWST programs on SPT0311-58, which clearly appears to represent an active and rapidly forming cluster core. This proposal is a key part of efforts to collect the required observations to uncover the extended protocluster properties of SPT0311, demonstrating that it traces the formation of a very massive structure in the early Universe. We propose to ALMA for followup of all red satellites, including those that extend the central structure of the core region. Our survey will provide an important baseline for models of the earliest massive galaxy cluster formation. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2022-12-12T02:04:07.000 |
| 585 | 2012.1.00498.S | 9 | The Effect of Extreme Environment on Protoplanetary Disks in Orion | Protoplanetary disks, or "proplyds" are the sites where new Solar systems are born. While most disk studies to date have focused on regions like Taurus and Ophiuchus for their proximity, stars rarely form in such isolated environments. In fact, there is clear evidence that our own Sun formed near a clustered OB association like Orion. To understand how planets form it is imperative that we study disk properties in regions representative of their origins. For this reason, we propose to survey the protoplanetary disks ("proplyds") around 295 young stars in Orion in order to study fundamental disk properties in a massive star forming region. ALMA is uniquely capable of imaging dust and gas emission from the Orion proplyds with its combination of high frequency, sensitivity, resolution and spatial filtering properties. We will measure the masses and survival timescales of these disks, study their molecular gas emission and spatially resolve the dust emission of the largest disks in Orion in order to determine their surface density profiles. The results of such observations will provide a detailed view into how the clustered environment and UV radiation affect disk properties and evolution, and ultimately, allow us to assess the potential to form Solar system analogs in a massive star forming region. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2016-08-25T00:32:29.000 |
| 586 | 2021.1.00133.S | 54 | Resolving the effects of environment on molecular gas in Abell 370 | We propose Band 5 observations to investigate the effect of environment on molecular gas over cosmic time by mapping the kiloparsec scale distribution and kinematics of CO(2-1) in eight spectroscopically confirmed members of the galaxy cluster Abell 370 (z=0.375). Combined with existing HST and upcoming JWST observations, these data will provide an unmatched view of the physics of star formation in galaxy clusters during the epoch in which the cosmic star formation rate declined. Our key science goals all require deep, resolved maps of cluster galaxies' molecular gas content which do not currently exist. With these data, we will directly address the question: how do galaxies form stars in different environments over cosmic time? We achieve all this with efficient observations requiring just ~30 hours of main array time in total. | Galaxy groups and clusters | Cosmology | 2023-09-29T20:44:05.000 |
| 587 | 2017.1.01527.S | 90 | Searching for feedback with 3D multi-phase interstellar medium study in z~2 quasar host galaxies | Luminous quasars are a thousand times more prevalent at z=2 than present day. This rapid period of super-massive black hole accretion coincides with the peak period of galaxy growth. Yet the effects of quasar activity on their host galaxies are still poorly constrained by observations. We are conducting a distant quasar host galaxy survey using integral field spectroscopy (IFS) and adaptive optics (AO) at the W. M. Keck Observatory. The advent of near-infrared IFS with AO allows studying morphology and dynamics of the ionized gas in quasar host galaxies. For cycle 5 we are proposing to observe the cold molecular gas reservoir of five z = 1.5 - 2.3 quasar host galaxies through CO J=3-2 or J=4-3 emission redshifted into band 4. Our sample contains quasars that have rich multi-wavelength data sets and have shown evidence of powerful extended ionized outflows. These outflows coincide with regions of low star formation. Critical high-resolution ALMA observations will allow us to investigate if molecular gas is absent in these outflow regions. Together with the lack of detected star formation, this will suggest for quenching of star formation due to negative quasar feedback. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-01-31T19:34:07.000 |
| 588 | 2017.A.00044.S | 45 | High-resolution map of H2O and H2O2 during the Martian global dust storm: Key for the habitability on Mars | The most striking phenomenon on Mars is a planet-encircling storm, "global dust storm". Once it starts, the floating dust covers the whole atmosphere for more than several weeks. Recent studies suggest that global dust storms effectively transport water vapor from the near-surface to the middle atmosphere and increase the escape rate of atmospheric water loss. The confirmation of such an atmospheric escape process is important to understand the evolution of Martian atmosphere. Currently, a very strong dust storm is developing on Mars for the first time after the previous one in 2007, and is highly expected to expand globally. This is a rare opportunity to observe drastic changes in the Martian atmosphere under such a strong dust storm. We propose high-resolution imaging of water vapor to investigate the impact of dust storm on the atmospheric state. Moreover, it is predicted that the amount of H2O2 could increase due to triboelectric field under dust storm. This may be responsible for scavenging organic material on Mars because H2O2 is a strong oxidizer. This proposal confirms or disproves such a dust storm-induced enhancement of H2O2. | Solar system - Planetary atmospheres, Solar system - Planetary surfaces | Solar system | 3000-01-01T00:00:00.000 |
| 589 | 2016.1.01284.S | 133 | Characterizing the size distribution of the youngest protostellar disks | While large circumstellar disks are observed around young stars, only a handful of large (r>100AU) candidate protostellar disks have been detected around the youngest (Class 0) protostars so far. Our recent results with the IRAM-PdBI CALYPSO survey established the paucity of young large disks, showing that >75% of Class 0 protostars have no resolved disks at radii r=60 AU, and therefore challenging the classical paradigm of disk formation as a natural result of angular momentum conservation. We propose to observe the 10 low-mass Class 0 protostars from the CALYPSO sample where no resolved disks are detected in our PdBI data (disk radii < 60 au) and that can be observed from ALMA (Dec<40°), carrying out high S/N continuum observations to perform the visibility modeling needed to probe disks down to ~10 au radii at the distances of our sources. The ALMA observations will reveal the density distribution in protostellar envelopes at radii 10-500 au. While larger disks are characterized from our PdBI observations, the ALMA spatial resolution will allow to probe the low-end of the protostellar disk size distribution, where we have shown >75% of the Class 0 protostars seem to stand. | Low-mass star formation | ISM and star formation | 2018-01-18T19:14:25.000 |
| 590 | 2024.1.00386.S | 0 | Probing host galaxy dynamical mass of the most luminous quasars at cosmic noon | To address the fundamental, yet unsolved, issue of supermassive black hole (BH) growth and its link to galaxy evolution, it is crucial to measure accurately the mass of both the central BH and the host galaxy. The combination of the on-going upgrade of the VLTI/GRAVITY interferometer, GRAVITY+, and the capabilities of ALMA provide a unique opportunity to make decisive progress. While GRAVITY+ will enable accurate measurements of BH masses from the size of the broad-line region out to beyond the cosmic noon epoch, ALMA can measure the dynamical mass of the host via submillimeter molecular gas line kinematics -- the only viable method for the most luminous distant quasars. Moreover, while host masses have been well determined for sizable samples of local and z>~6 quasars, few have been obtained at z~2. We propose to observe CO(3-2) line emission with ALMA to weigh the host galaxies of a unique sample of southern luminous quasars at z~2.3 for which GRAVITY+ will obtain accurate BH mass, and to bridge the existing censuses of host masses at lower and higher redshifts. This project will complete the survey begun in Cycle 10 to characterise host galaxies of the GRAVITY+ quasar sample. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-11-20T09:55:20.000 |
| 591 | 2023.1.01033.S | 0 | Mapping out the Changing Dust Properties of High-redshift Galaxies | ALMA has by now firmly established the importance and ubiquity of dust at high redshift (z > 5). However, our understanding of the physical properties of the earliest dust in galaxies remains severely limited by the scarcity of multi-band follow-up, and the few existing multi-band studies focusing solely on observations near the peak of the dust SED. Crucially, this leaves the dust emissivity index (beta) fully unconstrained, preventing any insight into the composition and size distribution of high-z dust grains, as well as introducing major systematic uncertainties in our knowledge of dust temperatures (+/- 30 K), masses and luminosities (> 0.5 dex). We here propose for Band 4 + 9 observations of 5 normal star-forming galaxies at 5 < z < 7.5 with existing multi-band ALMA data in order to 1) robustly measure dust emissivity indices in the first Gyr of cosmic time, and 2) accurately constrain dust temperatures and masses of high-z galaxies free from systematic uncertainties. With these observations, we will elucidate if galaxy dust properties evolve across cosmic time, and shed new light on the rate and efficiency of dust build-up in the early Universe. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2025-11-08T19:53:47.000 |
| 592 | 2023.1.00482.S | 0 | Chemical Keys to PPN Evolution: The Unique Case of V510 Pup | In recent years, the widespread role of binary influence in driving the physical evolution of post-asympotic giant branch stars has become clear. V510 Pup (IRAS 08005-2356) is one of a small group of proto-planetary nebulae that show early signs of the high-velocity bipolar winds typical to planetary nebulae, and its precessing jet is confirmed to originate from a companion on a 7 yr orbit. It is also chemically peculiar, exhibiting spectroscopic signatures indicative of both oxygen- and carbon-rich chemistry. Recent ACA data show that these chemical components trace distinct velocity structures, but since the molecular lines have not been spatially resolved, the chemistry cannot yet be tied in with evolutionary history of the source. We propose ALMA observations of V510 Pup to map the detailed physical and chemical structure of its outflow. The results will include a full characterization of major geometrical structures, spatial disentanglement of the reservoirs of C- and O-rich material, molecular abundances, and constraints on the dust distribution. This case study will thus offer crucial insights into binary-shaping and chemical evolution of rapidly evolving post-AGB stars. | Post-AGB stars, Evolved stars - Chemistry | Stars and stellar evolution | 2024-12-22T22:16:55.000 |
| 593 | 2013.1.01359.S | 9 | Probing The Star Burst Phase of Quasar Host Galaxies | Understanding the physical mechanisms and connection between supermassive black hole growth and galaxy formation and evolution remains elusive. In particular, observational properties of host galaxies of distant luminous quasars has remained challenging due to the high contrast needed to separate the bright quasar from the faint, resolved galaxy. We are proposing to observe two carefully selected quasars at a unique stage in their evolution where the host galaxy is undergoing a burst of star formation. In the submm regime we gain the necessary level of contrast to see the light from the host since the energy output from the host galaxy is far greater than due to AGN. Due to high angular resolution of ALMA we will be able to spatially resolve the host galaxy and study several key properties, including molecular gas distributions and masses, dynamical properties from resolved kinematics maps, and host galaxy morphologies. Our ALMA observations will be supplemented with adaptive optics assisted near-IR integral field spectroscopy observations, combining the two will give us a better understanding of the relationship between star formation and AGN activity at these early epochs. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-10-06T23:33:04.000 |
| 594 | 2019.1.01016.T | 110 | Radio Polarlimetry of GRB Afterglows | Gamma-ray Bursts (GRBs) are highly energetic explosions in the universe, and are currently being exploited as probes of first-generation stars and gravitational wave transients. Although the energetics of GRBs are fundamental physical parameters that reveal their progenitor systems, the total energies have been estimated so far without considering non-energized, cool electrons at the relativistic collisionless shock that do not emit observable radiation, while the existence of such cool electrons is well studied for supernova remnants and solar winds. As we demonstrated by making the first radio polarization measurement with our previous programs, linear polarizations in Band3 are essential for discovering these non-energized electrons, because the Faraday depolarization caused by the non-energized electrons suppress the linear polarization degree at a frequency of 100-1000 GHz. In this program, we intend to conduct linear polarlimetry at the millimeter wavelength together with simultaneous ACA photometry. The intensive studies of non-energized electron in a number of afterglows will make a revolutionary change in the GRB progenitors. | Gamma Ray Bursts (GRB) | Cosmology | 2021-04-15T22:07:46.000 |
| 595 | 2015.1.00897.S | 84 | Cold gas halos at z~2: evolution of massive galaxies within a molecular IGM | Giant Ly-alpha halos of warm gas have long been known to surround powerful high-z radio galaxies. We recently discovered large reservoirs of cold molecular CO(1-0) gas located beyond the radio lobes in the 100+ kpc-scale environment of three massive radio galaxies at z~2. These CO reservoirs are as luminous as those found in submm galaxies, but they lack any far-infrared counterpart in deep Spitzer imaging. These results suggest that large amounts of widespread and possibly diffuse molecular IGM may be spread throughout the halo environments of massive high-z galaxies. If so, it may provide observational evidence for predicted key processes that drive their early evolution, such as cooling flows, cold accretion, or jet-triggered star-formation. We propose to target our three CO-rich sources with ALMA to trace the full extent of the molecular IGM on >100 kpc scales and investigate its nature. We will use ALMA and ACA in their most compact configurations to maximize our sensitivity for detecting low surface brightness CO emission. This novel use of ALMA may ultimately give us new insights into the gas physics in the halo environments outside massive galaxies in the Early Universe. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-03-03T12:40:57.000 |
| 596 | 2017.1.01562.S | 53 | Water emission from the T Tauri star DG Tau: disk or outflow ? | The quest for the water reservoir in protoplanetary disks is crucial to understand the origin of oceans on terrestrial planets. We detected with Herschel/HIFI the fundamental lines of ortho- and para-H2O at 557 GHz and 1113 GHz towards a young T Tauri star, DG Tau. Both lines show a double-peaked profile consistent with emission from the warm disk surface out to ~90 AU. Surprisingly, the emission is ~20 times brighter than in the other T Tauri disk detected so far in these lines (TW Hya). However, the interpretation is limited by the low angular resolution of Herschel (beam ~19"-38") which does not allow to rule out possible contamination from a molecular outflow. We propose to obtain observations of DG Tau with ALMA in the H218O line at 203.4 GHz at ~0.3"-1.8". This will allow us to detect water emission down to a sensitivity of 0.5 mJy and to recover the line profile, hence to understand if the emission originates from the disk (compact emission showing double-peaked profile with ~14 km/s peak separation) or from the outflow (possibly extended emission showing high-velocity blue-/red-shifted wings) and to quantify the amount of water in the disk/outflow. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-12-17T18:09:19.000 |
| 597 | 2016.1.01125.S | 44 | Cluster formation within filamentary molecular clouds | Recent Galactic Plane surveys have revealed that filamentary structures are ubiquitous across the Galaxy. These filaments harbour overdensities that correspond to the location of future star formation. Single dish data have have provided insight into the understanding of the global properties of filaments, however, there are still many aspects of filament formation and evolution that are still not clear yet, such as: What are the physical mechanism that leads to the fragmentation of filaments and the formation of clumps and cores within them?, or Are flows within filaments responsible for the grow of their clumps? To answer these questions requires high resolution studies of the internal structure of filaments. Here we propose to study the small scale structure within a filamentary molecular cloud in an early stage of evolution. These observations will allow us to determine the fragmentation mechanism at their small scale. We also aim to determine the presence of fibres, or subfilaments, and to measure velocity gradient within the filament that can be associated with the mass grow of the cores embedded within the filament. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-10-15T00:00:00.000 |
| 598 | 2015.1.01341.S | 13 | The physical properties of extraplanar molecular gas in a galaxy under strong ram pressure | We propose to image two regions of NGC 4522 in 12CO (1-0), (2-1) and 13CO (1-0), (2-1). NGC 4522 is a Virgo spiral undergoing active HI stripping due to the ICM wind, and it is one of the few cases with clear evidence for stripped molecular gas some of which coincide with the extraplanar Halpha patches. Using multi-line diagnostics, we will probe the temperature and density distributions of molecular gas in two regions, one around the center of the galaxy, and one centered on the peak of the extraplanar CO. By studying molecular gas properties, we aim to study the stripping conditions for dense molecular gas and the star formation activities associated with the molecular gas inside and outside the disk. The kinematics of the molecular gas will also allow us to trace the stripping history. Our proposed ALMA data are expected to provide the most direct answer how one galaxy passively evolves due to ram pressure stripping in the cluster environment. In order to keep decent spatial and spectral resolutions while achieving enough sensitivity, we request 17.17 hours of observing time with the ALMA 12m array. | Spiral galaxies, Galaxy groups and clusters | Local Universe | 2017-12-06T09:25:09.000 |
| 599 | 2018.1.00947.S | 13 | Disk around a nearby resolved planet | We propose to search for the presence of cold debris disks surrounding the young 11^{+9}_{-2} Mjup planet of the VHS J125601.92-125723.9 substellar system. The planet is separated by 8" (128 AU at 16 pc) from the primary binary brown dwarf, which, together with its brightness, makes it an ideal target for an insightful characterization. The age of the system is well constrained in the interval 150-300 Myr. The proposed ALMA observations at 345 GHz (0.869 mm) will allow us to detect the thermal emission of cold dust (>15 K) contained in an unresolved disk around the planet with a disk-to-central-body mass ratio similar to that of Saturn. This finding will represent a break-through result and will open a new window for the study of planet--satellite systems. For its proximity and young age, VHS J125601.92-125723.9 is an exceptional substellar trio that will provide significant insight into the formation, evolution, and architecture of planetary systems. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2020-03-14T09:54:32.000 |
| 600 | 2015.1.00385.S | 2 | ALMA Explorations of Nuclear Regions of Nearby LIRGs: Warm Molecular Gas Distribution Down to GMC Scales | We propose ALMA mapping in Band-9 at 0.12"/beam of the CO(6-5) line emission and the 450 um dust continuum in the nuclei of 3 luminous IR galaxies (LIRGs), to complete our Cycle-2 program (Category-B priority) to characterize the nuclear dense molecular gas distributions in a set of 4 LIRGs at resolutions < 50 pc, characteristic size of GMCs. These targets were carefully chosen to represent the diversity of LIRGs, including 2 starbursts and 2 AGNs and representing two most common nuclear configurations: two taregts with a compact nuclear core of < 1" (< 300 pc) and two with a circumnuclear disk of 2" to 2.5" (500 to 1000 pc) in diameter. For the latter two, we also request a coarser array configuration to recover the structures associated with their nuclear disk. The ALMA results are crucial in determining physical gas/dust conditions in different nuclear configurations, spatial correlation between CO(6-5) and Pa-alpha emissions, the role AGN plays in gas heating and feedback, and if nuclear dense molecular gas remains in discrete GMCs or is compressed into spatially continuous molecular gas over scales much larger than 50 pc. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2017-09-01T17:30:43.000 |
| 601 | 2016.1.00132.S | 34 | A hidden reservoir of diffuse molecular gas in the galactic bar and bulge | A recently-delivered ALMA study of CF+ chemistry in the inner galaxy serendipitously detected strong molecular absorption from HCO+, HCN and HNC at -190 km/s and -150 km/s in the direction l = -2.13°, b = -1.00°, from gas at galactocentric radii 340 500 pc in the galactic bar/bulge, well outside the central molecular zone (CMZ). Corresponding CO emission is weak or absent, lending support to earlier suggestions that a substantial unobserved reservoir of diffuse molecular gas may exist in the bar/bulge outside the CMZ. To see whether the diffuse molecular gas is widely distributed, we propose to extend the search for absorption to the four suitably bright compact sources that are known within a few degrees of the galactic center, outside the CMZ. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-01-07T14:48:46.000 |
| 602 | 2021.1.00456.S | 41 | Mapping Molecular Irradiation Tracers in the Extreme Bipolar Planetary Nebula NGC 6302 | Planetary nebulae (PNe) offer our last and arguably best look at the products of intermediate-mass stellar nucleosynthesis, just before that material is incorporated into the ISM. Though best known as photogenic optical emission line sources, a subset of PNe with pinched-waist, bipolar structures retain significant masses of cold, dense molecular gas and dust that is irradiated from within by UV and soft X-rays from exceedingly hot, rapidly evolving central stars. Such extremes of physical conditions within individual, readily resolvable objects with well-defined molecular gas irradiation geometries make PNe fertile ground for dramatically improving our understanding of photon-dominated regions and X-ray-dominated regions, such as are found in a diverse array of astrophysical environments. We propose an ALMA molecular line mapping survey of NGC 6302, the archetype of the class of extreme bi-lobed/pinched-waist, molecule-rich, high-excitation PNe, that will provide unique new insight into the role of high-energy irradiation in driving molecular gas heating and composition. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR), HII regions | ISM and star formation | 2024-02-09T19:57:40.000 |
| 603 | 2022.1.01694.S | 24 | The newly discovered G337.92 hot core: a chemical twin of Sagittarius B2(N)? | The star-forming region Sgr B2(N) is commonly seen as a key search site for new complex organic molecules (COMs). Recent analysis focusing on other star-forming regions with high degree of complexity in their chemical composition, arises questions: how widespread are these COMs? Is the molecular composition of Sgr B2(N) unique? Is there a unified view on the origin of COMs ? The recent discovery of the G337.92 hot core, which shows stricking similarities with Sgr B2(N), will allow a great step forward to address these questions. In chemically rich sources, the firm identification of (new) molecules often requires a detailed analysis of the emission lines of weakly-emitting complex molecules. We propose to use ALMA in Cycle 8 to perform a deep, unbiased imaging line survey of G337.92 at 3mm. The requested high sensitivity combined with the large frequency coverage, should allow the detection of several COMs already identified toward Sgr B2(N) but not yet in G337.92. Comparing observed abundance ratios will allow us to confirm (or not) the resemblance of the two sources and to constrain the chemical/physical processes that lead to this resemblance. | High-mass star formation, Astrochemistry | ISM and star formation | 2024-04-18T19:49:56.000 |
| 604 | 2016.1.00254.S | 63 | Nuclear cold molecular gas, star formation, and the dusty torus of nearby Seyfert galaxies | The nuclear regions of AGN contain large amounts of molecular gas and dust with many AGN showing nuclear star formation (SF). While the mid-IR emitting torus is compact (<10pc), in many Seyferts the nuclear cold and warm molecular gas is extended over a few hundred pc. We propose to obtain ALMA Band 6 observations of the CO(2-1) line covering the nuclear/circumnuclear regions of 3 well-studied nearby Seyferts. We selected them as perfect candidates to fullfill our goals. These Seyferts present nuclear (<70pc) and circumnuclear (a few hundred pc) SF and have well-characterized sizes of the mid-IR emitting torus. We chose a 0.13-0.14" resolution as the best compromise to resolve both physical scales. The goals are: 1) to test whether the SF regions are at the outer radius of the torus or further out by resolving the morphology of the cold molecular gas, 2) to compare the gas mass to that of the torus by isolating the CO(2-1) emission at the AGN location, 3) to distinguish inflowing and outflowing gas masses and rates by careful modelling of the CO(2-1) kinematics, and 4) to understand the connection between the torus and the surrounding cold dust by using the continuum observations. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-02-23T17:51:39.000 |
| 605 | 2017.1.01119.S | 45 | Carbon fractionation at redshift z=0.89 | Isotopic ratios are powerful probes of the nucleosynthesis history of a galaxy, and the spectroscopic study of absorption lines toward bright background continuum sources provides a powerful technique to investigate them. Such absorption studies require a foreground galaxy in the line of sight to e.g. a quasar, and the most famous such system is the molecular absorber at z=0.89 towards PKS 1830-211. A range of isotopic ratios have been measured in this galaxy, and they are found to differ significantly from ratios in the Milky Way. However, potential fractionation has not been taken into account. Models show some molecules are more vulnerable to fractionation, such as CO, HCN, and HNC. Other molecules, such as CN and HCO+, are expected to reflect the true isotopic ratio. In order to study the 12C/13C fractionation in the molecular absorber at z=0.89, we will target the carbon-bearing molecules HCN, HNC, HCO+ and CN, and their 13C isotopologues. We will constrain the level of fractionation in the gas and derive the true 12C/13C isotopic ratio. This will also allow us to use previously measured double ratios to extract the isotopic ratios 14N/15N and 16O/18O. | Gravitational lenses | Cosmology | 2019-10-16T11:36:28.000 |
| 606 | 2018.1.01284.S | 1034 | A 350 GHz ACA Survey of Orion Protostars | We will observe 330 protostars in the Orion A & B molecular clouds with the ACA in Band 6. The primary goal of this observation is to meaure the 870 micron continuum from the infalling envelopes surrounding the protostars. With a 4" (1600 AU) resolution and the ability to detect structures out to scales of 20" (8000 AU), the ACA can isolate the envelopes from the surrounding dense molecular gas and obtain more robust measurements of the masses of the envelopes than can be measured using single dish telescopes from the ground or space. Combined with the 1.6-870 single SEDs constructed from 2MASS, Spitzer, Herschel and APEX data, these data will be used to probe how the envelopes deplete with time, and how this depletion regulates infall and accretion. Furthermore, using the diverse environmental conditions found in the Orion molecular clouds, we will examine the influence of the birth environments on the envelope masses and infall rates. These data will complement an ALMA 12 meter survey of the same protostars with an identical correlator set up which detected and resolved diskss with 0.08" resolution, providing the ability to observe the co-evolution of disks and envelopes. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2019-10-29T13:45:07.000 |
| 607 | 2017.1.00862.S | 46 | Alumina dust production in Mira stars | A common form of dust is alumina (Al2O3) which is produced by O-rich AGB stars, red supergiants, novae, and supernovae. Alumina forms from very refractory molecules (AlO and AlOH) and is the first solid that can form in the hot gas near the photosphere. Owing to its refractory properties, Al2O3 provides condensation cores for dust nucleation at lower temperatures. Although most M-type AGB stars chiefly produce silicates, some less evolved AGB stars produce as much alumina as silicates, and there are also stars that produce alumina almost exclusively. We propose observations that will spatially resolve emission of gas-phase precursors of alumina dust in two well-known Miras: R Leo, representing Al2O3-rich stars; and GX Mon, which produces both alumina and silicate dust. In our earlier work, we studied in detail o Ceti, which forms predominantly silicates. The three stars (R Leo, GX Mon, & o Ceti) constitute a sequence that will allow us to study systematic differences in alumina production in these mineralogically different objects. Our main aim is to investigate the efficiency of alumina dust condensation on the AGB and its role in forming silicates. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2018-12-07T18:18:33.000 |
| 608 | 2015.1.01525.S | 9 | Orbital Evolution of Proto-Binary Systems - Footprints in Protostellar Outflows | We propose to observe the molecular jets/outflows driven by a potential proto-binary system, IRAS 16253-2429, through CO (6-5). Protostellar outflow can be used to indirectly probes the dynamics of the driving sources. The collimated precessing H2 jet suggests IRAS 16253-2429 is a close binary system. We have derived the orbital velocity and period of IRAS 16253 from our SMA CO (2-1) outflow observations in which the position velocity diagram shows a sinusoidal variation. However, protobinaries can shrink or expand (migration) as the system evolves, which is crucial for binary formation. Our models suggest that the migration is observable through the outflow but high quality data is required. Our SMA CO (2-1) observations suffer from the contamination of cloud emission at low velocity range. In addition, our IRAM 30m CO (2-1) map shows that CO (2-1) is more likely to trace the outflow cavity instead of collimated H2 jet, while APEX CO (6-5) map well match it. Therefore, we propose to derive the orbital dynamics of IRAS 16253 through the jet with CO (6-5). Our proposed observation will provide an opportunity to measure the orbital evolution of binary at an early evolutionary stage. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-09-06T12:58:36.000 |
| 609 | 2019.1.01792.S | 2766 | Low Mass Protostellar Outflows: An Efficient Legacy Survey | Bipolar molecular outflows may be the dominant factor determining the initial mass function by extracting angular momentum and then dispersing the parent dense gas core. To date we have no complete census of nearby protostellar outflows, since it requires ALMA sensitivity and resolution. We will survey all embedded protostars of Chamaeleon, Ophiuchus, Aquila, Cor Aus, and Serpens from Dunham et al 2015. We will map 125 sources covering the full class 0 and I and the early class II Young Stellar Objects. We will use a single Band 6 spectral correlator setup to observe CO and other lines tracing the molecular outflow material, jet, envelope and disk gas on spatial scales of 150 to 2000 au with 1" angular resolution. In addition, we will obtain sensitive 7.5 GHz Band 6 continuum images with 0.1" angular resolution to determine YSO multiplicity and measure associated protoplanetary disks. These proposal will increase by a factor of 15 the early work done by Arce & Sargent (2006) to measure variation of outflow opening angle with age, and be the first complete census of nearby bipolar outflows with ALMA. These reference data will have a strong Legacy value. | Outflows, jets and ionized winds | ISM and star formation | 2021-02-23T21:12:05.000 |
| 610 | 2015.1.00331.S | 2 | A Tale of Two Cores: Stellar Birth in the Young L1451 Region | We have discovered a new dense core in the Perseus Molecular Cloud with CARMA. This core, which we call L1451-west, has structure and kinematics that closely match the L1451-mm first hydrostatic core (FHSC) candidate, while appearing to be younger than L1451-mm. These two sources are only 0.8 pc apart in the Perseus L1451 complex. The FHSC stage of star formation is predicted by theoretical models, but has never been definitely observed. There are only a few existing FHSC candidates, so the potential to add another source to list cannot be passed up. We propose ALMA observations of 1.3 mm continuum to search for compact continuum emission within L1451-west, and of 12CO(2-1) to search for a molecular outflow, both of which will help determine if this is a FHSC candidate, a starless core, or a low-luminosity protostar. We also propose for N2D+(3-2) and C18O(2-1) observations to study the structure and kinematics of cold, dense gas from this source at much higher angular resolution and sensitivity than our previous CARMA observations. These observations only require 0.8 hour of 12-m time, and have the potential to add a new candidate the small list of existing FHSC candidates. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-02-22T20:17:05.000 |
| 611 | 2021.1.00018.S | 512 | Exploiting a snapshot survey of the 3,083 reddest Herschel sources to reveal distant protoclusters | ALMA recently made a heavy investment of time in continuum observations of 3,083 ultrared DSFGs, all with S500>S350>S250, all imaged to sub-mJy noise levels at 1.2mm with ~arcsecond angular resolution. These data provide accurate positions, significantly improve the reliability of photometric redshifts, and reveal numerous candidate protocluster cores. They put us on the verge of a genuine breakthrough in the selection of distant protoclusters of ultrared, dusty, star-forming galaxies. Here, we propose to carry out 3-mm spectral scans for 12 of the reddest objects with multiplicities of >=3, to determine unambiguous redshifts and confirm protocluster membership. This survey will dramatically increase the number of extreme protocluster cores at z>4, allowing us to explore the most extreme star-formation events at cosmic dawn, testing models of galaxy evolution and structure formation to their limits. | Starburst galaxies | Active galaxies | 2023-01-14T00:35:58.000 |
| 612 | 2013.1.00025.S | 6 | The Origin of Debris Rings: Planets or Gas? | Imaged in scattered light, the bright dust rings around the 10Myr old stars HD 181327 and HR 4796A appear unusually narrow, with steep radial brightness profiles compared to other disks and theoretical expectations. The origin of these rings is unknown; they may be true debris disks where dust is created in collisions between large planetesimals, but may be a product of dust-gas interaction. Both disks also show departures from symmetry that may indicate the dynamical influence of planets, but could alternatively arise from dust-gas interaction. These scenarios have observable differences, which can only be tested with ALMA. We propose to use ALMA for 3.7h to image these two sub-mm bright rings to i) compare their radial extent to the scattered light emission to distinguish between collisional debris and gas-driven ring scenarios, ii) conclude whether the rings are truncated by planets, iii) use observed asymmetries to draw conclusions about the possible dynamical influence of planets, and iv) detect CO gas that may point to a gas-driven scenario. These results will shed light on the status of planet formation at 10Myr, shortly after dispersal of the gaseous protoplanetary disk. | Debris disks, Exo-planets | Disks and planet formation | 2016-10-13T08:55:30.000 |
| 613 | 2021.1.00693.S | 48 | Formation of complex organics around protostars in isolated cores | ALMA has since its beginning shown its great potential for astrochemical studies with many interesting discoveries of complex organic, and prebiotic, molecules toward low- and high-mass stars. However, significant questions concerning the formation of these species still remain, for example how important are the physical conditions in the environment of the protostars on the outcome in terms of their chemistry. So-far the complex chemistry has mainly been studied toward sources associated with relatively dense and clustered environments. However, recently ALMA has also revealed the presence of similar complex chemistries toward protostars located in isolated cores. This proposal will address whether the early physical evolution of protostars in such cores reflect in their chemistry. It will systematically measure the abundances of the molecules forming the basis for the first level of complex organic chemistry. These measurements will be interpreted in the context of laboratory experiments and detailed models and provide a new perspective on the link between the birth of individual protostars and the chemistry of their eventual protoplanetary disks. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-09-09T13:10:50.000 |
| 614 | 2023.1.01177.S | 0 | Atomic carbon in the circumnuclear disks and outflows of nearby AGN probed by CI (2-1) observations | AGN feedback is a fundamental process in galaxy evolution. The interstellar medium in AGN consists of multi-phase gas concentrated in a circumnuclear disk exposed to intense radiation and jets. One especially important constituent is atomic carbon (CI), whose abundance is expected to be enhanced relative to CO in AGN environments. To investigate the CI/CO abundance and gas physical conditions, we propose the first observations of CI (2-1) toward two nearby Seyfert 2 galaxies that exhibit different luminosities and feedback processes: (1) the AGN-dominated NGC 613 with nuclear jets and supressed star formation, and (2) the starburst-dominated NGC 1808 with high star formation activity in the dusty nucleus. Both galaxies exhibit molecular gas outflows from the central regions. The galaxies already have archival CI (1-0) and multi-line (J=1-0, 2-1, 3-2) CO data taken by ALMA at a resolution of ~30-50 pc. Using the newly acquired CI (2-1) and CO (7-6) data, together with the archival data, we will perform a non-LTE analysis to determine the CI/CO relative abundance and gas physical conditions at unprecedented accuracy. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-09-23T17:06:12.000 |
| 615 | 2011.0.00510.S | 0 | Probing the Molecular Outflows of the Coldest Known Object in the Universe: The Boomerang Nebula | The Boomerang Nebula is the coldest known object in the Universe. Single dish CO J=1-0 observations show that the high-speed outflow in this object has cooled to a temperature significantly below the temperature of the cosmic background radiation. We propose to map this ultra-cold nebula to determine the origin of these extreme conditions. The Boomerang is an key member of the class of Pre-Planetary Nebulae, objects which represent a short-lived transitional phase between the AGB and Planetary Nebula evolutionary stages. Its hourglass shape as seen in optical images of dust scattered light is in sharp contrast to the roughly round shape seen in a low angular resolution (45 arcec) CO map. The Boomerang's prodigious mass-loss rate (0.001 solar masses/year) and low-luminosity (300 Lsun) lack an explanation in terms of current paradigms for dusty mass-loss and standard evolutionary theory of intermediate-mass stars. High angular resolution mapping of the molecular gas distribution in the Boomerang will help resolve the apparent discrepancy between the molecular and optical morphology, and enable us to probe the fundamental physical properties of its ultra-cold outflow. | Post-AGB stars, Outflows, jets and ionized winds | Stars and stellar evolution | 2013-01-09T23:45:00.000 |
| 616 | 2019.2.00032.S | 324 | Capitalising on an ALMA snapshot survey of the 3,083 reddest Herschel sources | we propose to carry out band 5-7-8 continuum observations of the most exciting 16 potential z>4 proto-clusters, selected from an extraordinary ALMA band-6 snapshot survey of 3,083 ultrared dusty, starbursts, comprising all sources with S500 > S350 > S250 in the widest Herschel survey. The sample includes dropouts and 5% have colours redder than any known starburst. ALMA made it possible to carry out such observations, to 0.5 mJy/beam r.m.s. and with 1-arcsec resolution, well below the single-dish confusion limit, for 30x more ultrared galaxies than have been observed until now with ALMA, SMA, SCUBA-2 and LABOCA. Of the 3,083 sources, 11, 2 and 1% have two, three and more than three robust band-6 counterparts: a treasure trove of potential z>4 proto-clusters, structures whose very existence is a puzzle, and which represent a strong challenge to models of galaxy formation. With improved SEDs we can reject galaxy groups that are due to line-of-sight confusion and can isolate and focus thereafter on the genuinely exciting z>4 proto-clusters, where the SEDs of the individual galaxies are commensurate with the very highest redshifts, and with each other. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2021-04-17T07:23:28.000 |
| 617 | 2015.1.00294.S | 15 | Dense, Warm Molecular Gas and Star Formation in CO Luminous QSO Hosts | Our CO(1-0) survey of z < 0.3 UV-excess PG QSO hosts has shown that at least 38% reside in CO-rich host galaxies. We propose 0.1"-0.2" resolution ALMA Band 7 observations of CO(3-2) emission from four PG QSO hosts previously detected in CO(1-0). This sample has been selected to be nearby (z < 0.2), have a declination < 15 degrees, and to have CO(3-2) redshifted to a frequency with good atmospheric transmission. The CO(3-2) line is an ideal diagnostic line for star formation; it traces the dense, warm molecular gas component associated with high mass star-forming regions in galaxies. With these data, we will (a) measure the compactness of the CO(3-2) emission and its distribution relative to stellar light, (b) determine if the radio emission from these QSOs is co-spatial with the CO(3-2), and thus associated with star formation, and (c) make use of the CO(3-2)-IR luminosities relation of starburst galaxies to estimate the host star formation rates. This survey turns the focus of our extensive QSO work over the past few decades directly to diagnosing their starburst properties. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-01-11T02:21:13.000 |
| 618 | 2022.1.00972.S | 50 | Tracing CO-dark gas in ULIRG outflows using [CI] | Local ultra-luminous infrared galaxies (ULIRGs) host massive molecular outflows which have the potential to affect star-formation (SF) through AGN and SF feedback. To quantify feedback effects, it is necessary to accurately measure the molecular (H2) outflow mass. Molecular outflows are usually traced by low-J CO emission lines, but it is known that a fraction of H2 is not traced by CO (CO-dark gas). An alternative tracer of H2 is the [CI] 3P_1 - 3P_0 atomic carbon line. Recent studies have found an enhancement of the [CI]/CO(1-0) line ratio in the outflow regions compared to the disk. This could indicate that CO is depleted in the outflow and thus, CO-based outflow masses may be underestimated by a factor as large as 4-5. We plan to map the [CI] emission in a representative sample of 7 ULIRGs with molecular outflow detections, for which ALMA CO(2-1) archival observations are available at 0.3-0.6" resolution. We will measure the [CI]/CO ratio in the outflow and disk, and quantify the CO-dark molecular mass. This will help to reduce the uncertainties in the the molecular outflow masses and to assess the impact that molecular outflows can have on the galaxy SF. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2023-10-26T11:46:38.000 |
| 619 | 2023.1.00413.S | 0 | ISM and Kinematic Properties of Unlensed Extreme Starburst Galaxies at z~6 with SFR=1000-3000 Msun/yr | We request spectral imaging of three newly-identified unlensed galaxies at z_spec=5.8433-6.1702 with star formation rates of 1000-3000 Msun/yr and the IR luminosities of ~10^13 Lsun, comparable to ULIRGs/HyLIRGs in the local universe. Such extreme starburst galaxies are found at low and intermediate redshifts, but are rare at high redshifts especially z>~6, with only a few sources identified previously via gravitational lensing. ALMA Cycle 9 observations for the three galaxies show clear detections of [CII]158um, [OIII]88um, and dust continuum emission in multiple bands with a medium spatial resolution of 0.6". Here we propose to obtain 1) key diagnostic emission lines providing the estimates of physical quantities such as densities of neutral and ionized gas, ionization parameter, and molecular gas mass, and 2) higher resolution [CII] images to explore dynamics and stability of the ISM, without the uncertainty of the lensing model. This proposal will be the first study of unlensed extreme starburst galaxies at z>~6 with detailed multiple lines/high-resolution observations, and is crucial to understand the formation of these remarkable galaxies 1 Gyr after the Big Bang. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-07-11T13:47:46.000 |
| 620 | 2016.1.01417.S | 17 | Resolving feedback in a hyper-luminous AGN/starburst merger at z~2 | The Dragonfly Galaxy is one of the most IR-luminous radio galaxies in the high-redshift Universe. We recently concluded an ALMA pilot-project of this object, which revealed that this is a rare triple merger system, with possibly massive (10^10 Msun), bi-conical molecular gas outflows that arise from the merging, pre-coalescent nuclei. With one nucleus hosting a radio-loud AGN and the other most likely dominated by a starburst, this system has all the properties to study the different aspects of feedback on the evolution of massive high-z galaxies. We propose to follow up our 6-min pilot-project and image the molecular CO(6-5) gas within the putative outflows, trace its distribution/kinematics along the radio jet, and image the dust morphology of the presumed discs of the central nuclei. This will allow us to unambiguously confirm the presence of feedback-driven outflows, investigate their physical properties, and study their role in the evolution of this enigmatic object. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-10-06T15:36:53.000 |
| 621 | 2012.1.00635.S | 9 | The G2 Gas Cloud Encounter with Sagittarius A*: Accretion Structure on Scales of 3000 to 1 Schwarzschild Radii | Sgr A* in the Galactic Center is by now the best constrained supermassive black hole candidate. Its radio spectrum peaks at submm-waves and its size as measured with VLBI experiments shrinks with increasing frequency, exhibiting a clear size-frequency relation. The millimeter-wave emission comes from less than four Schwarzschild radii (R_S) and will allow imaging of the event horizon with mmVLBI in the future. The predicted close encounter of the G2 gas cloud in mid-2013 will provide an unprecedented opportunity to study accretion processes on scales from a few thousand to a few R_S and explore the accretion-jet coupling that may take place in Sgr A*. First discovered through NIR astrometric imaging, G2 contains at least 3 M_Earth of dusty, ionized gas that is undergoing tidal disruption and will reach periastron of 3100 R_S. The millimeter flux density will rise as gas reaches a few R_S, which could be as short as the free fall time of a few months or as long as the viscous time of years to decades. Increased accretion rates could lead to an order of magnitude increase in the flux density, which will be indicative of a new accretion-jet state that can be imaged with VLBI. The G2 encounter represents a low mass, large impact parameter analog to stellar tidal disruption events, which have recently been show to produce coupled accretion and outflow events. We request 10 epochs of band 6 and 7 flux monitoring to search for evidence of increased accretion onto Sgr A*. This proposal is part of a multi-wavelength campaign to study the G2 encounter; we have approved multi-epoch Chandra X-ray time to observe Sgr A* in 2013. Finally, the integrated data set coupled with our Cycle 0 data will provide the best-ever multi-frequency map of the gas streamers (Sgr A West) in the Galactic Center and probe for new compact structures. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2020-10-22T00:00:00.000 |
| 622 | 2017.1.00935.S | 26 | Using ALMA to Answer Why Galaxies Stop Making Stars | We have identified a unique sample of post-starburst galaxies in transition between late- and early-types. Such galaxies are ideal laboratories for studying how the interstellar medium evolves from star-forming to quiescent. Our work has revealed that CO-traced molecular gas remains after the starburst has ended. These galaxies lie offset from the Kennicutt-Schmidt relation, with SFRs much lower than expected for their CO luminosities. Why have these galaxies stopped forming stars? ALMA has revealed an answer: post-starburst galaxies lack dense gas reservoirs, as traced by HCN (1--0). However, the HCN/CO ratios span a range of >5x when compared to other post-starbursts in the literature, and thus may be sensitive to variations within the post-starburst sample. Additionally, it is not clear how the unusually low HCN/CO ratios of some post-starbursts might evolve to those of normal early type galaxies. In this proposal, we wish to examine the dense gas properties of two additional post-starburst galaxies, doubling our sample of quiescent post-starbursts, to determine the dense gas properties over a wider range of CO luminosities, post-burst ages, and recent starburst properties. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2019-11-15T10:32:20.000 |
| 623 | 2011.0.00097.S | 0 | Evolution of the ISM Contents of Massive Galaxies z = 2.2 to 0.3 | The interstellar medium in galaxies, specifically it's mass, is one of the major determinants of the galaxy characteristics (e.g., star formation rate and stellar population), yet the evolution of the ISM contents of galaxies over cosmic time is only loosely constrained by observations. We propose measurements of the dust continuum at 345 Ghz (Band 7) for 120 mass-selected galaxies from the COSMOS survey in three redshift bins from z = 2.2 to 0.3 to track this evolution -- a technique entirely independent of the uncertainties plaguing CO measurements, much quicker and probably more robust. | Galaxy structure & evolution, Surveys of galaxies | Galaxy evolution | 2013-06-11T14:27:00.000 |
| 624 | 2013.1.00877.S | 10 | Tracing Shock Chemistry in Luminous IR Galaxies: Spatially Resolved Shocks in Enhanced H2 Emitters | Local luminous infrared galaxies are dust-enshrouded, molecular gas-rich, intense starbursts that are usually inspired by major mergers. LIRGs thus provide an ideal place for an in depth look at the affects of mergers on the interstellar medium (ISM), specifically feedback from merger-driven star formation in the form of shocks. We select a sample of LIRGs that have a so-far unexplained excess of warm molecular hydrogen as revealed by Spitzer mid-IR spectroscopy. The IR data suffer from poor spatial and spectral resolution while optical observations have difficulty probing the dense and dusty ISM. ALMA provides the best tool for uncovering shocks in these dusty starbursts and for probing the shock chemistry to determine the extent, power, and dynamics of the shocked molecular gas. We propose to map these excess H2 emitters with dense molecular gas tracers CO and HCO+ to look for evidence of shocks/outflows and to determine the scale of their contribution to heating the ISM. We will also map the shock tracers SiO and methanol (CH3OH) to diagnose the strenghth, speed, and kinematics of any observed shocks and ultimately to determine the source of the shock. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2016-09-09T23:25:44.000 |
| 625 | 2024.1.00137.T | 0 | Revealing the Primitive Origins of Cometary Ices | The deuterium-to-hydrogen (D/H) and 15N/14N fractions in cometary ices are extremely sensitive to molecular formation conditions, and provide powerful diagnostics of the thermal and radiative history of volatiles and organic matter the protosolar disk midplane. The HDO/H2O ratio also reveals the possible contribution of comets to the Earth's water budget, but the distribution of D/H ratios in the comet population is still not well characterized. We propose to study isotopic ratios in H2O, HCN, CH3OH and H2CO in a target-of-opportunity (ToO) comet, to obtain new constraints on the origins and evolutionary history of cometary matter, and to provide a more complete understanding of the relative contributions of the various Solar System water reservoirs (e.g., comets vs. meteorites) to Earth's oceans. In a sufficiently bright comet (such as the upcoming A3/Tsuchinshan-ATLAS), we will obtain the first remote observation of D2O to test whether Oort cloud water ice originated primarily in the interstellar medium, or from more processed disk material. | Solar system - Comets | Solar system | 3000-01-01T00:00:00.000 |
| 626 | 2011.0.00014.SV | 0 | Science verification observation of Mira | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Evolved stars - Shaping/physical structure, Evolved stars - Chemistry | Stars and stellar evolution | 2016-06-24T14:02:07.000 |
| 627 | 2023.1.00970.S | 0 | Probing Deeper into the Multi-Phase ISM in SDP.11 at z ~ 1.8: Gas Physics on Sub-kpc Scales Using Gravitational Lensing | We propose to finish a detailed study of the ionized, atomic, and molecular gas in SDP.11, a gravitationally lensed, high-z, Ultra-Luminous Infrared Galaxy (ULIRG) analog, at z=1.783. The combination of this fortuitous lensing configuration and redshift allow us to map the [CI] 609 um, [CI] 370 um, CO(4-3), CO(7-6), and [NII] 122 um lines with ALMA, at sub-kiloparsec resolution, and the CO(1-0) line at kiloparsec resolution. This program was previously accepted, and the [CI] 370 µm and CO(7-6) lines were observed and strongly detected, before the observations timed out. These observations, combined with existing ALMA [CII] observations, ionized gas lines from Herschel, and multi-band radio free-free emission data, will allow us to estimate the ambient stellar UV radiation field strength, PDR gas densities, molecular gas density, temperature and mass, dust mass and temperature, and absolute [N/H] abundances, at sub-kiloparsec resolution across the source. By probing the gas physics of SDP.11 in all phases of the ISM - ionized, atomic, and molecular - we will learn more about the ways in which massive galaxies rapidly produced their stars at cosmic noon. | Starburst galaxies, Gravitational lenses | Active galaxies | 2025-07-29T23:03:51.000 |
| 628 | 2017.1.00212.S | 0 | Dust in the disk and wind launching region of TMC1A | In this proposal we aim to unambigiously detect dust in an outflow for the first time. Dusty MHD disk winds have long been suggested, but have never been directly observed. We recently presented a study of the Class I object TMC1A, where we report the first resolved images ever of an outflow launching region (Bjerkeli et al., 2016). These observations demonstrate that the gas in the outflow from TMC1A is launched from the disk surface out to radii of 20 au from the central protostar. Interesting features are, however, also detected in the dust continuum towards the disk. The goal of this project is to further characterize the dust in the disk and to unambiguously detect dust in continuum in the outflow cavity walls close to the protostar. We will use ALMA in its largest configuration, with 16 km baselines, to attain the highest possible spatial resolution. This study will put strong constraints on both the dust content of outflows and subsequently the initial conditions for planet formation. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-12-22T18:08:02.000 |
| 629 | 2013.1.00749.S | 21 | Dynamical Properties of Dusty Star-Forming Galaxies in the Peak Epoch of Star Formation | Dusty star-forming galaxies (DSFGs) at high redshift are thought to be dominantly highly dissipative mergers of gas-rich galaxies that represent extreme, short-lived starbursts. This picture is supported by studies of gas dynamics, but unfortunately, the resolution of these past studies remained limited to 3-4 kpc even for the best handful of cases (with only a single exception), which is barely adequate to resolve the galaxies. Using the advanced capabilities of ALMA in cycle-2 (in particular band 8 and the longest baselines) and the magnifying effect provided by gravitational lensing, we here propose to study the [CII] gas dynamics in a large, carefully-selected sample of 14 Herschel-selected DSFGs covering the peak epoch of galaxy formation down to 100-500pc resolution. Based on uv plane lens modeling and dynamical models, we will investigate the occurence rate of major mergers vs. disks in our sample, measure dynamical masses, and constrain the physical properties of individual gas clumps down to physical scales that will only become accessible with full ALMA in unlensed galaxies at these distances. This comprehensive investigation thus will remain unrivaled for years to come. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2016-10-24T21:57:01.000 |
| 630 | 2013.1.01230.S | 0 | Winds, dust, and gas in three of Planck's Dusty GEMS: Boosting ALMA's capabilities with the most powerful gravitational telescopes in the sky | The brightest, most strongly gravitationally lensed galaxies on the FIR/sub-mm sky provide unprecedented insight into the fine spatial details of the most vigorously star-forming galaxies in the early Universe. The Planck all-sky survey, complete down to 600 mJy (~5x10^13 L_s at z=2.5) and in combination with Herschel/SPIRE photometry, has enabled us to identify the brightest gravitationally lensed high-redshift galaxies on the sky, at spectroscopic redshifts z=2.2-3.6. As part of our comprehensive multi-wavelength follow-up of these extraordinary sources, we wish to use the ALMA 12-m-array to map the [CII] in the 3 sources observable from Chajnator, and to search for OH119, an excellent absorption-line probe of molecular outflows in G244.8, potentially the single brightest high-z lensed galaxy on the FIR sky. [CII] will provide us with the total UV heating budget and provide a base for a plethora of line diagnostics, including gas densities and radiation fields, when combined with various mm lines. Velocity gradients and line profiles will constrain gas turbulence and rotation, and may indicate a merger or winds. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-08-14T11:41:20.000 |
| 631 | 2022.1.00974.S | 1521 | Massive Star Forming Cores with Class II Methanol Masers | There are growing evidences suggesting that luminosity bursts occur in massive star forming regions (MSFRs). Compelling evidences also hint that Class II methanol maser flares are associated with such bursts. While single dish monitoring of methanol masers provides an efficient access to the flaring events, interferometric observations at submillimeter are required to localize the burst source in crowded MSRFs and to gauge the magnitude/fraction of the temperature and luminosity variability. Reference images from the pre-burst phase are strongly desired for thec comparison with follow-up observations triggered by maser flares. To assess the frequency and degree of the submillimeter continuum variability and constrain the nature of accretion bursts in MSFRs, it is imperative to monitor a statistically significant sample in a systematical manner. We propose submillimeter continuum observations of 169 MSFRs associated methanol masers using the ACA in Band 7. The simultaneous molecular line investigation will provide its own legacy value in charactering the physical properties of this unique sample. | High-mass star formation | ISM and star formation | 2024-07-25T19:07:28.000 |
| 632 | 2019.2.00246.S | 40 | The impact of accreting black-holes on the molecular gas excitation in dusty star forming galaxies | Molecular gas, normally observed at high-redshifts via high-J CO (J>=4) transitions, plays a fundamental role in galaxy and black-hole evolution. While a characterisation of the CO spectral line energy distributions (SLEDs) is critical for interpreting such high-J CO measurements, no systematic studies of the CO SLEDs exist at high-z, that characterise the impact of AGN on the interstellar medium. As the most complete sub-mm survey to-date, the ALESS survey of sub-mm galaxies (SMGs) offers an ideal laboratory to carry out such a study, carefully characterising any AGN contribution. Based on exquisite ancillary data, we propose to build a library of CO SLEDS (1 | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-08-20T00:00:00.000 |
| 633 | 2019.1.01085.T | 130 | Imaging the Sites of Dust Production in a Classical Nova | It is a well-established but continuing puzzle that dust forms efficiently in the warm, ionized, expanding ejecta of stellar outflows and explosions. Novae, which form dust on predictable timescales of weeks to months, are the best laboratories for a more general understanding of this phenomenon. Here we propose to use ALMA to monitor and then image a nova in the process of dust formation. This will allow a test of the hypothesis, motivated by multi-wavelength evidence for internal shocks in novae, that dust forms at radiative shock fronts internal to the ejecta. The ALMA image will allow a clear discrimination between this model and one in which dust forms in isotropic clumps, with direct implications for dust formation in other energetic outflows. | White dwarfs, Transients | Stars and stellar evolution | 2022-08-06T00:00:00.000 |
| 634 | 2017.1.00202.S | 76 | The extent of (by far) the most extreme starbursts in the early Universe | Interferometric follow-up of the reddest dusty starburst discovered in the widest far-IR Herschel survey led to the discovery of the most extreme proto-cluster of submm galaxies (SMGs) in the early Universe: the Great Red Hope (GRH). Its redshift (z = 4.002) was determined via CO, [CI] and water line detections in a mm spectral scan, and two or more of these lines are seen from at least six bright SMG components. The total star-formation rate (SFR) of the proto-cluster is then SFR~8000Mo/yr (!!). Additionally, a wide LABOCA map revealed that GRH is part of an even larger overdensity of bright SMGs. Here we aim at confirming if the six closest SMGs to GRH belong to the same structure, meaning that the SFR of the proto-cluster would be an impressive 13000Mo/year (!!). We will also estimate the total baryonic mass of the dusty components of the proto-cluster and their gas depletion time to explore their evolution. Will GRH evolve into a massive cluster of galaxies at z~3, already dominated by massive red-and-dead galaxies? Our unique proto-cluster represents an ideal system to confront our understanding of cluster galaxy evolution derived from theory and computational modelling. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2019-07-31T11:24:45.000 |
| 635 | 2016.1.00961.S | 22 | The CO Snow Line and Temperature Structure of the HL Tau Disk | We propose to search for the CO snow line in the spectacularly structured disk around HL Tau. Snow lines and the midplane temperature structure they trace are an integral component of planet formation. Neither has been previously probed in a disk as young and active as the one around HL Tau. This has limited our ability to interpret the observed ring system in the HL Tau disk in the context of planet formation models. We propose to search for N2H+, a robust probe of CO freeze-out (Qi et al. 2013), in this system. If detected at sufficient SNR, the ALMA data will provide strong constraints on the CO snow line location of the HL Tau disk and also pin down the disk temperature structure, which will have profound implications on the condensation of volatiles in this very young object. | Disks around low-mass stars | Disks and planet formation | 2017-12-15T16:36:00.000 |
| 636 | 2012.1.00239.S | 1 | Probing a mass distribution of the central 1000AU toward a dense core very close to a moment of the first protostellar core phase in Taurus | A mass distribution around the collapse center of dense cores within ~1000 AU, where most of the stellar mass is included, is a key to understand the physics of protostar formation. This central area has not been investigated because the current existing interferometers are not sensitive to the corresponding spatial frequencies. In this proposal, we will carry out ALMA observations toward a dense core very close to a moment of the first protostellar core phase in Taurus, MC27 or L1521F, in dust continuum at 250GHz and 345GHz. The inclusion of the ACA 7m array is essential for the science because the 12m+7m array will enable us to recover a size scale of ~15”, which can connect the single dish scale of ~10” to interferometry scale of ~1”. This observation will reveal for the first time the inner most mass distribution that should regulate the dynamical evolution and the fragments of the surrounding dense cores to the protostar. | Low-mass star formation | ISM and star formation | 2021-03-12T00:00:00.000 |
| 637 | 2015.1.00614.S | 6 | Accretion dynamics in the warped disk of HD142527 | Detailed optical/IR observations of HD~142527, along with molecular line data, have revealed stellocentric accretion through an inner warp, tilted at 70deg with respect to the outer disk. Accurate knowledge of the warp hydrodynamics would guide research on the physics of accretion in protoplanetary disks, and may explain the large central cavity in HD142527. Abrupt warps, and associated disk tearing, are a recent theoretical discovery and this would be the very first observation of the phenomenon in nature. The warp in HD142527, where molecular line and spectral diagnostics constrain physical conditions, allows new tests of hydrodynamics, as well as a measure of the disk viscosity alpha. In Cycle3 we can observe the warp dynamics, and detect material linking the two disk orientations. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2018-10-17T00:00:00.000 |
| 638 | 2017.A.00025.S | 0 | Where do the spirals come from? A multi-wavelength, high-resolution study of the HD 135344B transition disk | In Cycle 4 and 5, we obtained Band 3/4 observations at 0.05" and 0.07" resolution of HD135344B, a transition disk showing spiral arms at near-IR and asymmetric structures in the mm. HD135344B is an ideal candidate to look for the still missing connection between the scattered light and mm-dust structures and the above data provide the right resolution at optically thin wavelengths for this study. Both observations were however obtained with the extended configuration only: the larger spatial scales are missing, and the resolved flux densities are unreliable. We request DDT to obtain the missing short baseline observations. The requested observations and the high resolution ones will allow us to constrain the dust properties inside the asymmetry. We aim to calculate the dust mass of the crescent to see whether it is massive enough to launch spiral arms, to constrain the maximum grain size throughout the disk, to test if dust growth and planet formation are potentially occurring and to measure the azimuthal shift of the dust asymmetry at different wavelengths, predicted by hydrodynamical simulations. Ultimately, the data will constrain the presence of young planetesimals in the disk | Disks around low-mass stars | Disks and planet formation | 2018-07-22T15:34:02.000 |
| 639 | 2016.1.00772.S | 58 | Deep CO Mapping of NGC 55: Extra-planar Molecular Gas in Spiral Galaxies | Extra-planar layers in spiral galaxies are the interface between the IGM and star-forming disk and are essential for understanding disk-halo flows. They have been studied extensively for all ISM phases with the exception of molecular gas. All other ISM components show extended extra-planar material, most connected to star formation. It remains to be seen if this is true for the molecular component. Recent observations have found evidence for extra-planar molecular layers in face-on or moderately-inclined galaxies. These studies, however, were completed for face-on or moderately-inclined galaxies, and thus unable to fully-constrain their heights. Ideally, extra-planar layers are observed edge-on. Such observations have been performed for two galaxies - NGC 891 and NGC 4565, and they show strikingly different results. Thus, extra-planar molecular gas varies between galaxies and must be observed in a larger sample. We start with NGC 55, the nearest well-studied edge-on galaxy and thus the ideal template for studies of galaxy evolution and star formation. Using the unique power of the ACA, we will map the vertical extent of CO (1-0), a strong tracer of molecular gas. | Spiral galaxies | Local Universe | 2018-04-26T04:59:20.000 |
| 640 | 2015.1.01576.S | 139 | Probing Episodic Accretion in Very Low Luminosity Objects | We propose to observe N2H+ (1-0) and C18O (1-0) toward eight Very Low Luminosity Objects (VeLLOs). Our goal is to probe episodic accretion which is used to answer the long-standing Luminosity problem (Kenyon et al. 1990). Episodic accretion models consider that a protostar is at a quiescent accretion status for most of time and accretion bursts occasionally occur to deliver material onto the central star. The accretion luminosity of a protostar undergoing episodic accretion process will vary through an accretion burst. It is difficult to detect a significant variation of luminosity since the timescale for an accretion burst is very short. However, the luminosity variation can be found in the chemical vestige. The N2H+ depleted hole toward a source center can be caused by an increase of luminosity and it can preserves for a long time after the accretion luminosity decay. Therefore, studying N2H+ depletion provides us an opportunity to identify a protostar which has experienced an accretion burst, and explore evidences of episodic accretion process. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-08-02T00:00:00.000 |
| 641 | 2018.1.01236.S | 95 | Resolving the Super Star Clusters in the Nuclear Starburst of NGC 4945 | We propose to observe the nuclear starburst region of the very nearby (d=3.8 Mpc) galaxy NGC 4945 to confirm the existence and measure the properties of a set of ~20 candidate super star clusters suggested by previous ALMA imaging. If confirmed, this will only be the second galaxy with a large population of well-characterized, forming young super star clusters (after NGC 253), and only the fifth external galaxy with any resolved proto-super star cluster. We propose a combination of Band 7 and Band 3 observations that will allow us to estimate the dynamical mass, gas mass, dust opacity, and associated stellar content of the young clusters. These observations will give us a snapshot of super star cluster formation, allowing us to test current cluster-formation models, estimate the timescales for cluster formation, evaluate the likely impact of different types of feedback, and assess how much of the star formation in the NGC~4945 burst occurs in a clustered mode. | Starbursts, star formation, Galactic centres/nuclei | Active galaxies | 2019-10-30T01:44:02.000 |
| 642 | 2017.1.00884.S | 41 | Where the large grains are in transition disks? | Transition disks (TDs) are circumstellar disks with inner dust cavities and reveal an intermediate step of disk evolution. The recent gas and dust observations of TDs have given major support to particle trapping as the cause of the seen structures, such as rings and asymmetries. However, ambiguities remain because of the optical thickness of the emission inside the observed structures at short wavelengths. We propose continuum observations of three transition disks at ~100 GHz (3mm) at a spatial resolution of 0.1arc, in a regime in which the emission is optically thin. Such observations will determine whether or not large grains are concentrated inside the observed sub-structures, and will bring important insights of where the first cradles of young planets are located in protoplanetary disks. These observations will be combined with archival data tracing the distribution of the micron, mm- and cm-sized particles at different wavelengths, to provide critical constraints on the origin of pressure traps. | Disks around low-mass stars | Disks and planet formation | 2019-03-19T00:00:00.000 |
| 643 | 2015.1.01043.S | 14 | Exploring the star formation activity and kinematics of a GRB host at z=4.6 | Gamma Ray Bursts (GRBs) are very useful tools to identify and explore the most distant star-forming galaxies in the universe. GRBs also have great potential as tracers of the star formation history of the universe, however, this requires a detailed understanding of the properties of their galaxy hosts. At z>4, our knowledge of the GRB host population is very limited. This is why we propose to image at 2.6 kpc resolution the [CII] 158 micron emission from the GRB host 090205 at z = 4.6. This galaxy has a UV-based, extinction corrected SFR of ~30 Msun/yr and a metallicity among the highest measured in the high-z GRB host population (Z > 0.3 Zsun). Our [CII] observations will provide information on key aspects of the GRB host: (1) cooling of the gas and star formation activity as traced by the [CII] transition, (2) photoelectric heating efficiency of the gas as traced by the L_[CII]/L_FIR ratio, and (3) kinematics of the neutral gas and dynamical mass of the host. As the number of GRB detections continue to increase, this set of ALMA [CII] 158 micron observations can lead the way to many future spectroscopic studies on GRB hosts at z > 2. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2017-09-13T16:55:23.000 |
| 644 | 2023.1.01067.S | 0 | Searching for Complex Organic Molecules in Orion Cold Cores | Interstellar complex organic molecules (COMs) are thought to be formed on warm grains (>30 K) and desorbed at high-enough temperature (>100 K). The detections of COMs in starless cores such as L1544 challenge the existing chemical model. Many chemical models were put forward to explain this but are mostly not well constrained by sufficient observations. Previous observations were mainly carried out with single-dish telescopes and biased to individual famous cold cores. We propose ALMA Band 3 observations towards 5 extremely dense prestellar cores with the 12-m Array, aiming to detect transitions of COMs, such as CH3OH, CH3OCH3, and NH2CHO. With these data and previous ACA data of 16 cold cores, we will for the first time systematically study the spatial distribution and segregation of COMs in cold cores and their connections to the core evolutionary statuses. These informations are essential to constrain the chemical models of COMs. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2025-04-01T19:12:11.000 |
| 645 | 2019.1.00292.S | 6 | 3D Positions, Velocities, and Accelerations of SiO Masers in the Inner Parsec | We propose to measure precise positions and velocities of circumstellar SiO masers close to the Galactic central black hole (Sgr A*). Position and velocity tracking of masers within 1 pc of Sgr A* will provide 3D positions, velocities, and accelerations, enabling precise mass measurements at various radii. One can therefore probe the stellar mass distribution in the inner parsec, provide a reference frame for near-IR observations of stars directly orbiting Sgr A*, and enable multiple direct probes of the black hole metric. 3D tracking of stars close to Sgr A* can test the equivalence principle, the ''no-hair'' theorem of black holes, and frame-dragging, but only if stellar scattering is not too large, which the proposed observations can address by measuring the stellar potential at many radii. The proposed observations will be combined with extant VLA and ALMA observations and will yield errors on position of ~2 milliarcseconds, on Doppler shifts of ~8 m/s, and on accelerations of ~5 m/s/yr. A 2020 epoch is required to measure independent ALMA proper motions and reconcile observed offsets from VLA astrometry. We require only 16 minutes of on-source integration (52 minutes total). | Galactic centres/nuclei | Active galaxies | 2023-04-08T14:47:01.000 |
| 646 | 2015.1.01572.S | 82 | AGN Feedback and its Role in Galaxy Evolution: gas and stellar kinematics of radio-loud early-type galaxies | Galaxy formation theories struggle to explain the quenching of star formation and the formation of sub-structures in early-type galaxies (ETG). The solutions to both problems may well be connected: molecular gas can feed active galactic nuclei and generate feedback, while also leading to new decoupled stellar components. We have already obtained VLT/VIMOS integral-field unit spectroscopy and 12CO(2-1) line observations with APEX for a complete volume-limited (z<0.03) sample of 10 southern radio galaxies. Here, we request follow-up CO(2-1) imaging of the 9 objects rich in molecular gas. Our targets differ from ETGs studied previously at similar spatial resolution (100-300 pc), being significantly more massive and harbouring active jets. We will thus be able to isolate the role played by jets (likely the dominant feedback mode in local ETGs) in the overall formation and evolution of ETGs. ALMA is essential and ideal for the proposed mapping and, using Atlas3D as a radio-quiet control sample, our sample is appropriately sized for a first study aiming to identify and contrast trends. | Outflows, jets, feedback, Early-type galaxies | Active galaxies | 2017-07-20T14:56:25.000 |
| 647 | 2023.1.00962.V | 0 | Probing Relativistic Jets through mm-VLBI of X-ray Binaries | One of the key open questions in high energy astrophysics is understanding how black holes act as powerful cosmic engines, gravitationally capturing material and expelling matter in the form of relativistic jets. Stellar-mass black holes in Galactic X-ray binaries are ideal test-beds for jet phenomena, as they vary over rapid timescales, providing a real-time view of the accretion-jet coupling in black holes. Radio-VLBI has resolved jets down to milli-arcsec scales (~10^8 R_g at kpc distances). However, the mm/sub-mm wavebands, probing emission much closer to the black hole (~10^6 R_g), have yet to be thoroughly explored. Recently, two X-ray binaries were observed with the GMVA, achieving detections on only few baselines. Here we propose a modified experiment, adding the ALMA station and changing the target list, both of which will help to mitigate the sensitivity limitations of the earlier study. With these data, we will create high angular resolution images to measure jet morphology, size-scales, speed, geometry, and energetics. These pioneering GMVA+ALMA observations will also pave the way towards a coordinated multi-wavelength campaign with the Event Horizon Telescope array. | Black holes | Stars and stellar evolution | 3000-01-01T00:00:00.000 |
| 648 | 2013.1.01037.S | 3 | Are there non-fragmenting massive dense cores? | The fragmentation of massive dense cores is a crucial process at the origin of stellar cluster formation. However, observational work with pre-ALMA interferometers has revealed a clear inefficiency in the fragmentation process, compared to what is expected if it was controlled by gravity. In particular, there are clear examples of cores which intriguingly show no fragmentation at all down to 1000 AU. Although the magnetic field and radiative feedback may play a crucial role to explain these non-fragmenting cores, there is still the possibility that a hidden population of very low-mass fragments is missed by the observations due to poor sensitivity and dynamic range of pre-ALMA instrumentation. In this proposal we plan to observe two cores showing very low fragmentation levels, and two cores showing high fragmentation levels. ALMA will improve the sensitivity by a factor of 20, and the dynamic range by more than one order of magnitude, providing key information about the true nature of non-fragmenting massive dense cores. If a low-mass population of fragments is discovered in these cores, the current theoretical and numerical work on fragmentation of clouds should be revised. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2016-11-01T11:45:09.000 |
| 649 | 2015.1.00994.S | 73 | Weighing the Galactic Bulge Planetary Nebulae | To resolve the question of the origin of dual chemistry in GBPNE, we propose to measure the 12C/13C and 16O/18O ratios using the HCN and H2O molecules and their isotopologues to determine the progenitor mass for a sample of 5 Galactic Bulge planetary nebulae (GBPNe); if we confirm them to be high mass objects, this will indicate that recent star formation event took place in the Galactic Bulge, with implications for our understanding of the evolution and enrichment of the Bulge. | Evolved stars - Shaping/physical structure, Evolved stars - Chemistry | Stars and stellar evolution | 2017-07-25T16:36:06.000 |
| 650 | 2022.A.00023.S | 5 | Submm Maser in NGC 1052 | ALMA has just detected the 321-GHz water maser emission in the radio galaxy NGC 1052. This is the first discovery of sub-mm maser in a radio-loud active galactic nucleus and the most luminous 321-GHz maser ever known. In order to clarify the spatial distribution of the maser components, we propose a DDT observation with the C-10 configuration that offers a 0".013 resolution corresponding to 1.15 pc. With high SNR > 20, the array yields position accuracy of 0.1 pc with respect to the unresolved continuum core. Our aims are (1) concrete evidence for non-thermal emission with the brightness temperature > 2000 K, (2) location of the masers with respect to the unresolved continuum core with a sub-pc accuracy, and (3) velocity gradient of the masers to assess dynamics near the central supermassive black hole. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-02-17T03:01:38.000 |
| 651 | 2021.1.00970.S | 132 | Circumnuclear Holes around Supermassive Black Holes | Galaxies and supermassive black holes (SMBHs) are likely co-evolving, and the most accepted paradigm is an evolutionary process that involves self-regulating feedback from active galactic nuclei (AGN). Recent high-resolution observations of nearby galaxies are revealing ~10-100 pc CO holes at their circumnuclear regions in 20 % of the galaxy, independent of their current nuclear activity. The origin of these circumnuclear holes are unknown, but their radii typically corresponds to the SMBH potential, suggesting that the SMBHs are the cause. If these holes are developed without powerful AGN, the SMBHs must be creating these holes through heating or dynamical effects. This suggests secular effects can impede accretion of gas, making it harder for AGN accretion to occur. To unravel the cause of these circumnuclear holes, we propose to observe the HCN(1-0), CO(1-0) and CO(6-5) lines in three galaxies with known CO(2-1) holes, to probe the presence of gas and analyse the physical state of the SMBH surroundings. The results will help to clarify the origin of circumnuclear holes, and thus will reveal direct evidence of their feedback even without a luminous AGN. | Galactic centres/nuclei | Active galaxies | 2022-10-08T23:55:17.000 |
| 652 | 2018.1.01759.S | 48 | Understanding the spinning dust emission from NGC 2023 | Anomalous microwave emission (AME) is a dust-correlated radio emission with a spectrum peaking around 20-60 GHz. It is thought to originate from small dust grains spinning at GHz frequencies. It has been observed in different Galactic environments but the carriers of this emission mechanism remain unidentified. Until now, most of the observations of AME have been performed at moderate angular resolution (> arcmin) which do not allow for a clear identification of the AME emitters. We have detected for the first time AME at high (~3 arcsec) angular resolution using the VLA at 27.5 GHz in the reflection nebula NGC 2023. These observations show a strong morphological correlation with PAH emission at 8um. We propose ALMA + ACA Band 4 observations in order to map the thermal dust emission from the cloud at similar angular scales as our VLA data. With these observations we will be able to confirm that the emission seen by the VLA does not correspond to thermal dust. Moreover, we will be able to make detailed morphological comparison between both data sets and additional IR templates in order to identify which are the carriers of the AME. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2020-02-27T00:02:52.000 |
| 653 | 2021.1.01498.S | 85 | Co-spatial gas feeding of SMBHs and remnant SF regions in "IR-pure AGNs'' | FIR radiation of galaxies is typically dominated by thermal emission of star-formation (SF) dust. However, utilizing Swift/BAT AGN Spectroscopic Survey we found 12 galaxies where the IR radiation is almost fully contributed by AGN even in FIR band (hereafter "IR-pure AGNs"). All of the IR-pure AGNs locate under local SF main sequence, suggesting the final phase of gas consumption and AGN life for this system. More interestingly, the depletion time of molecular gas by remnant SF is found to be tightly associated with lifetime of AGNs, impling that gas feeding of remnant SF and SMBH could be co-spatial, i.e., molecular gas distribution is compact with the SF region concentrated in the vicinity of SMBH. Therefore, the IR-pure AGNs are good candidates of galaxies with gas feeding both SF and SMBH, which could reflect a stage in co-evolution of SMBHs and host galaxies when SF is quenched in galaxy scale but remains in the vicinity of SMBH. In order to directly determine the compact gaseous structure and reveal the co-spatial gas feeding of SMBHs and circumnuclear SF remnants, it is crucial to trace the molecular gas in the IR-pure AGNs with spatially resolved observations using ALMA. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-09-30T07:38:36.000 |
| 654 | 2013.A.00021.S | 14 | Clarifying a Detection of the [CII]Line from a z=7.215 Lyα Emitting Galaxy | Probing ISM, dust, dynamics of galaxies to earlier Universe across epoch of reionization (EoR) at z>6 can reveal how galaxies formed and reionization progressed. [CII] is strongest ISM line in galaxies and traces star formation rate (SFR). Various z~0–6 galaxies follow a clear SFR–[CII] luminosity L(CII) correlation, but recent ALMA observations have failed to detect [CII] from z~6.5–7 EoR galaxies possibly due to insufficient depths. Their L(CII) limits are marginally consistent with the SFR–L(CII) correlation or lower. If lower, EoR galaxies have different ISM state than z<6 galaxies, implying drastic galaxy evolution across EoR. We observed a galaxy at even earlier epoch z=7.215 in Cycle 2 and found a 3σ signal consistent with [CII] line. If it is indeed [CII], it marginally follows the SFR–L(CII) correlation. If not, the lower L(CII) supports rapid galaxy evolution across EoR. To clarify this, we request 3h of DDT to deepen our data. The galaxy is also currently undetected in dust continuum. Deeper data will detect it or push the system to the realm of extremely dust-poor galaxies. Moreover, deeper data allow us to constrain dynamics of the galaxy and reionization state at z>7. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2016-09-24T14:30:34.000 |
| 655 | 2021.2.00090.S | 33 | Large dust particles in the peculiar comet C/2017 K2 | The Oort cloud comet C/2017 K2 (hereafter K2) is remarkable for developing a coma at a record heliocentric distance of 35 au. The detection of K2 beyond the orbit of Uranus offers an unprecedented opportunity for us to examine the evolution of a pristine comet arriving into the inner Solar system from near-interstellar temperatures. The well-preserved dust and ice in this pristine comet holds valuable information about the physical processes during the formation of the Solar system. Our goal is to map the thermal emissions from large dust particles over four ALMA bands, 3, 4, 6 and 7 to yield strong constraints on the millimeter-sized grains, which dominate the coma mass of K2, via dust modeling. We will also study the heliocentric variations of the gaseous speices of K2 in 3 ALMA bands. The superb sensitivity of ALMA provides the only way to study the large particles of this peculiar comet. This study will shed light on our understanding of the formation of the protoplanetary disk of our Sun and possible disk processes for planet formation around other stars. | Exo-planets, Solar system - Comets | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 656 | 2013.1.00664.S | 2 | From Hydrocarbons to Dust in Protoplanetary Nebulae | We propose to observe two carbon-rich protoplanetary nebulae (PPNe), CRL 618 and CRL 2688, to investigate the physical and chemical conditions that lead to complex hydrocarbon chemistry in the circumstellar environment of evolved stars after the AGB phase. Polyacetylenes and cyanopolyynes have been detected with ISO in both sources. However benzene, the first aromatic ring, is only seen in CRL 618. Only CRL 2688 shows emission from dust grains rich in aliphatics. For both molecules and grains, UV-processing was invoked as a key process in driving the chemical evolution. We want to explore the emission of vibrationally excited HCCCN in both sources, CCH, HCN, CN and CO to constraint the physical and chemical conditions. In addition towards CRL 618, HCO+ and a recombination line of Hydrogen will be observed to better characterize the photodissociation region (PDR) at the interface between the HII region and the torus. Only ALMA can addressed this project since PPNe have complex morphologies and the most active chemistry is expected to occur in the densest part at scales of 0.2 to ~1". We will obtain unique data to investigate carbonaceous grain formation and evolution. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2016-09-23T23:36:45.000 |
| 657 | 2017.1.00955.S | 278 | A search for hot corinos in COM-rich embedded low-mass protostars | Low-mass protostars are analogs to the Solar Nebula and therefore offer a unique opportunity to understand the chemical evolution leading up to the formation of our own planetary system, which is of great interest in the study of origins of life. We previously conducted a survey of Class 0/I protostars with the IRAM 30m telescope and detected complex organic molecules (COMs) in the envelope of about 50% of the sources. We propose to perform follow-up observations on 8 of these sources to test whether such large-scale organic chemistry is correlated with the presence of COMs on small scales, i.e. hot corino chemistry. By targeting methyl cyanide, methanol, and other COMs with transitions spanning excitation temperatures up to 100K, we will determine rotational temperatures and probe for hot central emission. Observations with two 12m configurations and the 7m ACA will resolve the inner envelope at sub-arcsecond resolution while maintaining sensitivity to extended envelope emission. Ultimately, this will aid our understanding of how complex organic chemistry develops in solar-type protostars, which is crucial to evaluating the chemical habitability of other planetary systems. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-12-06T17:53:55.000 |
| 658 | 2012.1.00426.S | 4 | A First Measurement of the [NII] 205um/[CII] 158um Ratio at z=1 | We propose to use ALMA band 9 to observe the [NII] 205 um transition in 5 galaxies at z=1.2 from which we have detected emission in the [CII] 158 um fine-structure line. The [CII] transition is emitted by molecular gas ionized and heated by stellar UV radiation, and in the ALMA era promises to be the single most important high redshift star formation tracer. The [NII] 205 um line is a sensitive tracer of ionized gas, and complements the [CII] line as a star formation diagnostic. We will use the [NII] 205 um line to measure the fraction of the molecular ISM in these galaxies that has been ionized by stellar radiation, and use this to determine the intensity and spatial scale of the starburst. We will also use the [NII] line, compared with the continuum emission, to trace the hardness of the UV field, thereby determining the spectral type of the most massive stars or inferring the presence of an AGN. Finally, we will use the [NII]/[CII] ratio to determine how much of the measured [CII] arises from ionized gas rather than PDRs. This measurement will shed light on the anomalous [CII]/CO ratios measured in some of our sample galaxies, and will be an essential reference for future ALMA high-z [CII] studies. The current version of the OT calculates this program will require 2.5 hours of onsource time, and a total time of 6.5 hours. However, due to known bugs in the calculation of calibration measurements for band 9 this total time is likely an overestimate, and will be reduced after the next OT update. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2015-07-09T20:44:30.000 |
| 659 | 2013.1.01307.S | 5 | Beyond megamaser disks: understanding AGN central engines | Extragalactic water masers in AGN central engines (so-called megamasers) probe either the AGN accretion disk at radii < 1 pc from the supermassive black hole, or the AGN jet -- ISM interaction, or in some targets both. They tend to be found in Compton-thick Seyfert 2 objects, and, because they can be mapped with milli-arcsecond resolution using radio VLBI at 22 GHz, they have proven to be very useful tools for determining the structures in the central parsecs of their host galaxies. In this proposal, we request to observe two megamaser galaxies with the goal of exploring the AGN Unified Model. In addition, we aim to determine if we can utilise a new mass determination method for measuring the super-massive black hole masses in these galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-08-20T12:09:13.000 |
| 660 | 2022.1.01735.S | 0 | The puzzle of the methanol maser rings - What are the physical processes behind observed methanol maser regions? | Direct studies of high-mass star-forming regions are difficult due to their large distances, high densities of their birth clouds, and rapid evolution. It is still not clear if high-mass star formation is a scaled-up version of low-mass star formation (accretion via an ordered disk with a connected jet/outflow system). Class II methanol masers are a useful tool to study processes close to the forming star as their bright and compact emission allows their detection on mas scales. However, it is unclear if the maser emission is tracing the accretion disk or the footprint of the jet/outflow system. Methanol maser rings have recently been detected in several high-mass star-forming regions. These rings suggest a connection with the accretion disk but the proper motion studies indicate expansion. We chose five targets for high-spatial resolution follow-up observations to resolve the dust and gas at similar spatial scales as the rings to understand which star formation features are being traced by the rings and the methanol masers in general. We aim for measurements of inner and outer radii of the discs around the high-mass protostars and registration of where the outflows begin. | High-mass star formation | ISM and star formation | 2024-12-28T12:48:46.000 |
| 661 | 2013.1.00879.S | 25 | Ongoing or Suppressed Disk Formation at the Early Stage of Star Formation | We propose ALMA observations toward four Class 0 protostellar sources selected from our SMA sample. Our SMA results show that these Class 0 sources exhibit little envelope rotation at 1000 AU scale, and the inferred radii of Keplerian disks in these sources are <10 AU, suggesting that they are at the early stage of formation of large-scale Keplerian disks. Therefore, these are excellent targets to study how large-scale Keplerian disks seen around T Tauri stars are formed. With the proposed observations, we aim to reveal the radial profiles of rotational velocities and hence the angular momentum transfer from the outer envelopes at hundreds of AU scale to the inner 10 AU disk-forming regions in these Class 0 sources. We have calculated theoretical radial profiles of rotational motion including the effect of magnetic field. We will compare the observed and theoretical rotational profiles, and discuss that the growth of Keplerian disks from 10 AU to 100 AU scales at the early stage of star formation is ongoing, as expected in the conventional picture of star formation, or is suppressed, as predicted in several MHD simulations by magnetic braking. | Low-mass star formation | ISM and star formation | 2016-08-03T19:12:58.000 |
| 662 | 2019.1.00402.S | 1 | Resolving ionized accretion flow toward most massive O-type stars | Massive protostars must accrete 40 to 60 Msun to become O stars, but they begin core hydrogen burning well before reaching their final masses. At a stage equivalent of an early to mid O star, the surface temperature is high enough to create a significant HII region around the star. This poses a challenging puzzle: How does accretion proceed through the pressure differential between the cold molecular and hot ionized gas? Our previous ALMA obervations produced the first spatially resolved imaging of accretion flows in ionized gas toward a dense protostar cluster G10.6-0.4. The goal of this proposal is to further resolve the accretion and investigate how the flow redistributes among individual O stars in the G10.6 cluster. The outcome of the project promises a significant step forward in understanding the formation of early O stars in the Milky Way and has implications to the formation of stars at the top of the IMF in the universe. | High-mass star formation | ISM and star formation | 2023-09-21T17:47:12.000 |
| 663 | 2024.1.01179.S | 0 | A Complete View of Low Metallicity Star Forming Complexes in the Local Group Dwarf NGC 6822 | We request 0.9 (2 pc) resolution 12 CO(2-1) and 2.5 (6 pc) resolution [CI] 609 um observations of three star-forming complexes in the very nearby, low-metallicity dwarf galaxy, NGC 6822. Combined with best-in-class multiwavelength observations of gas and dust that are available for this galaxy, the proposed observations will complete our picture of the physical and chemical structure of low-metallicity star-forming complexes. These CO observations are significantly deeper and provide coverage at large angular scales than previous observations, allow us to map out CO-dark gas. We will directly trace the CO-dark gas using [CI] observations over the same fields-of-view, and archival [CII] maps. We will use these data to make direct comparisons with models of molecular clouds at ~1/3 solar metallicty. Finally, a comparison with JWST PAH and small dust grain observations over the same fields of view will be used to test the viability of using PAHs to trace CO-dark molecular gas. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 664 | 2013.1.00803.S | 9 | Probing the Embedded Disk of the Giant Elliptical NGC 5128 (Centaurus A) | Many large elliptical galaxies contain embedded disks of dust and gas, remnants of a merger with a smaller gas-rich galaxy. The physical properties of such disks, and the resulting initial conditions for star formation are very different from those in disk galaxies and starburst galaxies. We will study these in detail by modelling the molecular gas in the embedded dusty gas disk ('dark band') of the only nearby giant elliptical, NGC 5128 (host of the radio source Centaurus A). We will apply PDR and radiative transfer models to the optically think 12CO and the optically thin 13CO and C18O J=1-0 and 2-1 transitions in maps of 18 pc resolution over the inner several kpc of the galaxy. From the maps we will deduce the mass and temperature, for individual clumps and as a function of radius, of the gas in the extended disk, and investigate the relation of the dense molecular gas conditions to the enhanced star formation in the disk. | Early-type galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2016-09-29T07:49:18.000 |
| 665 | 2017.1.01099.S | 14 | Witnessing the onset of environmental quenching in the most distant X-ray cluster at z = 2.51 | We propose CO(3-2) observations of ~15 member galaxies (with 3 pointings) of an X-ray-detected, starbursting galaxy cluster at z=2.51. Our previous observations of this cluster core have unveiled a surprisingly low gas content for its star-forming (SF) members, despite that most of them are located on the SF main sequence. Signatures of a cluster-radius dependence of the gas fraction are also observed, which, if confirmed, could represent one of the first evidence of environmental quenching of massive galaxies at z > 2. However, current analysis is severely limited by small number statistics at larger cluster-centric radii and the fact that nearly all the CO-detected galaxies so far are limited to the most massive ones. Our proposed observation will extend previous CO observations to much larger radius and lower stellar masses (~10^10 Msun), enabling the most comprehensive census of gas content of cluster galaxies at z > 2. This will push forward our understanding of the role of environment in the early formation of cluster galaxies. | Galaxy Clusters | Cosmology | 2019-05-14T16:42:31.000 |
| 666 | 2013.1.00039.S | 5 | A fine structure line survey to determine the metallicities of the earliest galaxies | With a modest ALMA survey of the four bright far-IR fine-structure lines ([NII] 122 and 205 micron, [OI] 146 micron, and [CII] 158 micron) we will characterize the gas in ionized and photo dissociated regions in a set of four star forming galaxies at z>4. We will establish the density of the ionized and photo-dissociated gas regions, characterize the intensity of the far-UV radiation, and constrain the numbers of Lyman continuum photons. This will provide new insight into the first chapters of galaxy evolution by determining star formation rates, the spatial extent of star formation, and nitrogen to carbon abundance ratios which will give the first unambiguous indications of metallicity in galactic ionized regions within ~1.5 Gyr of the birth of the Universe. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2016-03-16T13:17:57.000 |
| 667 | 2019.1.00156.S | 29 | CO spectroscopy for remarkably luminous Lyman break galaxies at z=6.030-6.203 | We propose Band 3 observations for three remarkably luminous spectroscopically confirmed star-forming galaxies (SFGs) at z=6.030-6.203, whose [CII] and dust continuum emission have been detected in our recent ALMA observations. This proposal aims at detecting their CO(6-5) emission and characterizing the properties of molecular gas components in SFGs at high redshifts, which has been poorly investigated in previous studies. We have two science goals: 1) Detecting CO emission lines from normal SFGs beyond redshift 6 for the first time and 2) Examining the redshift dependence of the gas depletion time in SFGs up to this high redshift. Even an extreme case of no CO detection is interesting, because such a result would suggest that invalidities of the empirical relation and/or the theoretical models, which need to be tested for high-z sources. This ALMA program will be a precursor study of our systematic survey for investigating the molecular gas properties of normal SFGs at high redshifts via CO emission line spectroscopy, which will be complementary to other studies targeting nebular fine-structure lines from high-z SFGs. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2021-03-03T15:54:37.000 |
| 668 | 2017.1.01439.S | 200 | IBISCO-south: mapping feeding and feedback in an unbiased sample of local AGN | We have recently undertaken a survey of molecular gas in an unbiased sample of AGN, drawn from the INTEGRAL IBIS hard X-ray AGN catalog to have z<0.05,Lbol>10^43 erg/s, and measured black hole masses. IBISCO survey @IRAM/30m is delivering H2 masses, their correlations with AGN properties (Lbol, MBH, Eddington ratio, obscuration), and host galaxy properties (stellar mass, colors, SFR). We propose to extend the single-dish investigation by mapping at 50-100 pc resolution the CO(2-1) emission in all the IBISCO galaxies with CO(2-1) detection, and visible from ALMA. We aim at a) mapping the kinematics of the molecular gas in the inner kpc around the AGN, identify molecular disks or circumnuclear disks, derive the dynamical masses; and b) detecting and mapping non circular motions, including molecular outflows and inflows, and their interaction with the molecular disks. We will use the broad, asymmetric and high velocity CO line profiles to identify outflowing molecular gas, and derive outflow velocity, mass, mass and energy rates. We will build scaling relations between molecular outflow properties and AGN and host galaxy properties (black hole mass, Lbol, Eddington ratio, SFR). | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-10-09T05:16:27.000 |
| 669 | 2013.1.00922.S | 5 | The interplay between a submillimetre galaxy and the circumgalactic medium at z=3 | Lyman-alpha Blob 1 (LAB1) in the SSA22 field is the archetypal and best-studied system of its class: a 100kpc scale emission line nebula at z~3. LAB1 epitomizes many of the key features of our current model of galaxy formation: the extended Ly-a nebula is host to two Lyman Break Galaxies and, at its centre, a SCUBA-2 850um-detected submillimetre galaxy (SMG). Our best model of LAB1 that combines morphological, kinematic and polarization observations suggests that the central galaxy is driving a cold, clumpy outflow off which Ly-a photons, leaking from the central SMG, are scattering. LAB1 is therefore a unique laboratory for studying the interplay between luminous high-z galaxies and their circumgalactic medium, the physics of which is a key part of all galaxy formation models, since this is the environment where gravitational cooling and feedback are in concert. We propose a simple experiment with ALMA to further our understanding of LAB1 by (a) pinpointing the location of the SMG relative to the surrounding Ly-a and (b) determining its systemic redshift allowing us to relate the source to the velocity structure of the extended gaseous halo. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2016-07-31T10:13:29.000 |
| 670 | 2016.1.00859.S | 81 | Opacity Variability in Neptune's Troposphere | We request time (~2h) to view Neptune in the millimeter. Spatially resolved millimeter maps of Neptune reveal brightness temperature variations in Neptune's troposphere (1-5 bar). These variations are mostly due to latitudinal variations in opacity. Previous millimeter maps of Neptune were unable to resolve the source of these variations, e.g. CH4, H2S, or ortho/para H2. ALMA provides the resolution, sensitivity, and wavelength coverage needed to constrain the source of opacity variations. Unraveling what contributes to the brightness variability is crucial for understanding Neptune's atmospheric circulation pattern. | Solar system - Planetary atmospheres | Solar system | 2018-01-27T03:36:03.000 |
| 671 | 2015.1.00896.S | 2 | The mass of the black hole in NGC 1332 | In Cycle 2 we began a program to identify optimal targets for measurement of the masses of supermassive black holes in early-type galaxies by mapping the kinematics of circumnuclear molecular disks. Our recently obtained Cycle 2 observations of NGC 1332, at 0.3" resolution, clearly demonstrate that its disk is in near-perfect circular rotation, and we detect high-velocity emission (up to +-500 km/s) from rotating gas within the black hole's dynamical radius of influence. However, the Cycle 2 data are not sufficient to determine the black hole mass accurately, due to the degeneracy between the black hole and the spatially extended stellar mass distribution. Here, we propose to obtain new CO(2-1) observations at 0.04" resolution which will resolve the black hole's dynamical sphere of influence exquisitely well, enabling us to determine the black hole mass accurately via dynamical modeling of the disk rotation. The proposed observations will represent a spectacular showcase for ALMA's revolutionary high-resolution capabilities, and the new data will have the potential to provide the most accurate mass measurement ever obtained for a very high-mass (~10^9 solar mass) black hole. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2017-01-04T18:16:11.000 |
| 672 | 2016.1.00382.S | 13 | Imaging Vibrationally-Excited Molecules in Galaxy Nuclei | We propose very high resolution (5-11 pc = 26-64 mas) imaging of three compact obscured nuclei of infrared luminous galaxies in emission lines from vibrationally excited molecules. These lines are unique probe of the innermost warm regions of the luminous obscured nuclei because their excitation is due to infrared radiation and their upper energy levels are as high as ~300-1000 K. We will first find out whether or not the vib-lines are from a single unresolved source (as expected for AGN). Together with high-resolution continuum images to be simultaneously obtained, we are further going to reveal the structure of the nuclei (e.g., disk or torus), measure the temperature and luminosity distribution within each nucleus, and obtain nuclear gas kinematics, dynamical masses, and mass to luminosity ratios. These information will be used to constrain the dominant energy sources in the nuclei (e.g., L/M of an AGN can be 10 times higher than the maximum for a starburst). Evolution of the energy sources will also be constrained (e.g., L/M of a starburst rapidly declines with age), and our data are sensitive to any outflow and inflow related to fueling and quenching of the nuclei. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-11-16T23:50:49.000 |
| 673 | 2016.1.00565.S | 93 | Characterizing the Gas Surface Density and CO Abundance Strucutre in Disks with Known Gas Masses | In this era of high resolution spectrocopic observations there is an emerging picture of substantial reprocessing of volatile elements in protoplanetary disks. Unraveling this story of volatile reprocessing, and its implications for the composition of forming planets, requires a solid understanding of the inital atomic reserviors, such as CO for carbon. However, determing if CO has been reprocessed requires knowledge of the total disk gas mass. We prospose to observe 13CO 6-5, C180 6-5, 13CO 3-2, and C18O 3-2 in DM Tau and GM Aur, the only two systems besides TW Hya whose total disk mass is well constrained by unresolved observations of HD, an excellent tracer of H2. Using these data we will derive a radial temperature profile and constrain the total gas surface density profile. We will then use the same observations to map the CO abundance in these systems, allowing us to quantify and identify spatial variations in the extent of CO reprocessing. Our group's previous analysis of similar observations in TW Hya directly resolve the surface CO snowline and constrain the CO freeze-out temperature to <21 K. | Disks around low-mass stars | Disks and planet formation | 2017-12-15T20:25:34.000 |
| 674 | 2022.1.01742.S | 6 | First limb sounding of Titans atmosphere with ALMA | ALMA observations of Titan at an angular resolution of ~0.2" have provided new remarkable results on the spatial/vertical distribution of minor species and winds in Titan's atmosphere from 200 to 1000 km altitude, including the first ever measurement of winds in the thermosphere. They point out the need for even higher spatial resolution with a beam actually resolving Titan's ~1300 km-thick atmosphere. The goal of this proposal is to map selected Titan's molecular species (HCN, HNC, HC3N) in band 7 at an angular resolution of 0.06 arcsec, corresponding to 450 km linear on Titan's disk, and 1/3 of Titan's atmospheric extent. These first limb sounding measurements from the ground, which will be performed in configuration C7 will allow a direct investigation of: (i) the vertical and spatial distribution of HCN, HC3N and HNC, (ii) the wind vertical profile, particularly above 500 km, (iii) the temperature field over 200-1200 km These high angular resolution observations will be key to characterize Titan's climatic system, especially in the 500-1000 km region, pooly sampled by Cassini, but key for couplings between the stratosphere and thermosphere. | Solar system - Planetary atmospheres | Solar system | 2024-08-08T20:40:12.000 |
| 675 | 2019.1.00320.S | 19 | Emission mechanism of the gamma-ray binary PSR B1259-63/LS 2883 | We propose the observations of the gamma-ray binary PSR B1259-63/LS 2883 consisting of a 48-ms radio pulsar and a Be star with a circumstellar disk. We aim to reveal the interaction between the two stars and the emission mechanism of the binary. In our ALMA Cycle 5 observations, we detected the binary in the millimeter/Submillimeter wavelengths for the first time. At that time, the pulsar had just crossed the disk and the binary was bright because of the pulsar-disk interaction. By comparing the previous observations with this one in Cycle 7 during a quiescent period of the binary, we can study the variability of the synchrotron and disk emissions. The observation will clarify the destruction of the circumstellar disk around the Be star by the passage of the pulsar and the subsequent disk recovery. We will discuss the contribution of the photons radiated from the disk to the gamma-ray emission through inverse Compton scattering. We can also estimate the power of the pulsar wind and the density of the disk. | Disks around high-mass stars | Disks and planet formation | 2021-03-27T08:02:22.000 |
| 676 | 2013.1.00191.S | 11 | Blowin' in the Wind: the Properties of the Starburst-driven Wind in NGC 253 | Using ALMA observations in cycle 0 we have imaged the starburst-driven molecular outflow in the nearby starburst galaxy NGC 253 (Bolatto et al. 2013a). These observations demonstrated that the molecular outflow carries enough mass to substantially shorten the current star formation episode in this galaxy. It is unclear whether the gas can escape the galaxy, or only reach into the halo to be later recycled. To escape, the molecular gas needs to be accelerated, possibly through mixing with the faster ionized wind. This study will measure the extent of the CO emission away from the starburst, and the distribution of velocities in the molecular wind. It will also measure the acceleration, and provide further insight into the physical entrainment and mass-loading mechanisms of the outflow. Finally, the observations proposed here will allow us to refine substantially our estimate of the mass-outflow rate. Together, they will shed unprecedented insights in the fundamental properties of the nearest starburst galaxy accessible with ALMA. | Starbursts, star formation | Active galaxies | 2016-03-11T15:56:07.000 |
| 677 | 2015.1.00338.S | 26 | To launch or not: A study of magnetic fields in post-AGB objects with and without massive outflows | The study of magnetic fields in evolved stars is crucial for understanding the extreme departures from spherical symmetry that occur in the late stages of stellar evolution. Indeed the field's ability to launch and collimate the bipolar jets believed to be involved in the shaping of the envelopes of post-AGB (pAGB) objects is a matter of intense debate. But the observational study of magnetic fields so far is very limited. We therefore propose to use ALMA and its new full continuum polarization capability to study magnetic fields through observations of linear polarization of dust grain emission, in two well-studied pAGB objects. These are OH231.8+4.2 and the Red Rectangle, with the former showing a massive outflow and the latter a very weak one. The high-resolution ALMA data will allow us to detect and map the field at small scales and test the outflow-launching mechanism in each object. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-10-24T01:45:33.000 |
| 678 | 2016.1.00125.S | 56 | Primordial Multiplicity at Massive Star Birth | ALMA now has the ability to see fine details around massive protostars. Observing continuum & lines at 1.3mm, we aim to detect substructure, especially multiplicity, disk & outflow features, in 8 massive protostellar cores at scales down to ~60 AU. This sample is part of a larger MIR/FIR survey with SOFIA. Radiative transfer models are being utilized to test geometries of dust structures, especially outflow cavities, via this IR emission. We are observing the 8 sources with ALMA in Cycle 3 from 10" to 0.14" scales, i.e., to ~300AU. Observations proposed here will be combined with those from Cycle 3 to give the highest spatial dynamic range possible. We also observed all 8 sources with HST in the last year. One goal is to detect jet/outflow knots at ~0.15" resolution. These may show high proper motions of ~0.14"/yr, so it is desirable for high angular resolution ALMA observations, which may also detect these features, to be executed as soon as possible to minimize proper motion drift. Overall, the results of this project will provide powerful tests of massive star formation theories, as these make widely varying predictions on the degree of primordial multiplicity & substructure. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2020-01-11T15:16:37.000 |
| 679 | 2022.1.01326.S | 5 | The Size and Albedo of New Horizons Large TNO Targets (556416) 2014 OE394 and 2014 OJ394 | Trans-Neptunian objects (TNOs) preserve some of the solar system's most primordial material and, via their shapes, sizes, and albedos, contain information about the processes that built the planetesimals. As TNOs from different dynamical populations, cold classical (CC) TNOs and those from the scattered disk (SDOs) have experienced very different thermal and collisional histories. NASA's New Horizons (NH) spacecraft has observed many TNOs at high Sun-TNO-observer (solar phase) angles. We propose to observe two NH TNOs with ALMA, one CC TNO, 2014 OE394, and one SDO, 2014 OJ394, to determine their sizes and geometric albedos. When combined with 'high phase' NH observations, ALMA enables measurement of their Bond albedos and evaluation of the thermal energy budget of their surface. Because the trans-Neptunian region is a relic of the Sun's protoplanetary disk, the ALMA observations proposed here provide access to the fundamental physical properties of individual components of the Sun's circumstellar disk. This synergistic combination of NH and ALMA observations enhances the return from the NH mission and ALMA by delivering science results that neither facility can provide alone. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2024-10-31T14:32:57.000 |
| 680 | 2013.1.00468.S | 0 | Detecting the second generation protoplanetary disk around NNSer | The recent frequent detection of giant planets around detached post-common envelope binaries (PCEBs) may significantly influence our understanding of planet formation. These circumbinary planets have likely formed from the expelled material following the common envelope evolution of the host binary system. Such a second generation scenario, if confirmed, could provide crucial constraints on planet formation theories. An ideal test-bed for the hypothesis of second generation planet formation is the PCEB NNSer with its two circumbinary giant planets. The common envelope evolution of NNSer occurred only a million years ago thus any second generation protoplanetary disk will still be detectable with ALMA. We therefore here request 1.16 hrs in band-6 to ultimately test the second generation planet formation scenario. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2016-04-15T21:33:44.000 |
| 681 | 2013.1.00534.S | 3 | Is the Central Engine of Markarian 590 Running Out of Fuel? | Sometime during the last few years the broad permitted emission lines in the optical spectrum of Mrk 590 have completely disappeared! This goes firmly against our current understanding of active galaxies in the framework where the presence of broad lines depends on source orientation only. Studying extreme behavior such as this often provides the most profound insight and understanding of the physics of active galaxies. It is therefore pertinent that the reason for this unusual behavior be investigated. One plausible explanation is that the central engine is running out of fuel causing the accretion and, hence, the broad line emission to cease. We ask to obtain deep observations of the warm gas in the central regions of Mrk 590 to measure the mass, distribution, and kinematics of the central gas. The aim is to establish if indeed the center is void of gas or whether Mrk 590 may be experiencing cyclic accretion such that the nuclear activity may be revived in the near future. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2015-08-05T14:11:39.000 |
| 682 | 2016.2.00079.S | 30 | Where is Deuterium Enrichment in Infrared Dark Clouds? | We propose to investigate the deuterium enrichment in cold dense infrared dark cloud (IRDC) cores by imaging the distribution of the important deuterated molecular ions H2D+ in the two young, infrared-quiet prestellar cores, G305.7994-0.2445 and G305.3666+0.2130. The great sensitivity of the 7-m array enables us to probe the emission distribution across the desired spatial scales from 3.8" to 19", comparable to the Jeans length of the IRDC and the core sizes, respectively. Due to its weak emission, H2D+ has never been imaged with existent millimeter arrays. Our study will provide the first set of interferometric images of H2D+ to better assess the discrepancies between current observational results and theoretical predictions such as lack of correlation in emission peaks among deuterated molecular ions and large difference in line widths. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2018-11-13T06:41:07.000 |
| 683 | 2016.1.00051.S | 72 | AGN feedback and molecular line flux ratios in dust/gas-rich ultraluminous infrared galaxies | Although scrutinizing deeply buried AGNs in merging dust/gas-rich ultraluminous infrared galaxies (ULIRGs) is very important to understand how supermassive black holes grow in mass in the early universe, it has been hampered by large dust extinction. Molecular line flux ratios in the (almost) dust-extinction-free (sub)millimeter wavelength range can be a powerful tool for this purpose, because an AGN and a starburst have different energy generation mechanisms and so feedback to the surrounding molecular gas can be different. Based on pre-ALMA and our ALMA Cycles 0 and 2 observations, it is argued that enhanced HCN emission is a good AGN indicator. However, its effectiveness is not fully verified yet, because some exceptions exist. We propose ALMA observations of nearby ULIRGs with isotopologues of HCN, HCO+, and HNC to estimate flux attenuation of HCN, HCO+, and HNC by line opacity. Our ultimate goal is to establish the most solid energy diagnostic method of dusty ULIRGs, based on line-opacity-corrected intrinsic molecular flux ratios. ALMA's high spatial resolution, high sensitivity, and stable spectral baseline are crucial for the success of this experiment. | Galactic centres/nuclei, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-01-05T08:45:54.000 |
| 684 | 2015.1.00116.S | 3 | ALMA study of extremely buried active galactic nuclei identified by the Swift/BAT all sky surveys | We propose to use ALMA to obtain 1" resolution (110 - 160 pc) images of CO(2-1) and 1.2mm dust continuum of two "New-type" AGNs, ESO005-G004 and NGC 7172. The Swift/BAT all sky survey and subsequent X-ray follow up result in a discovery of a new class of AGNs, i.e., heavily buried AGNs that exhibit very small fractions of scattered soft X-ray (only < 0.5%). Their SMBHs would be embedded by geometrically thick tori with very small opening angles. A possible key mechamism to form and sustain such a thick structure is a circumnuclear starburst. Our primary goal is to measure the molecular gas mass (Mgas) and dynamical mass (Mdyn) in the central r < 60 - 80 pc region. We assess the gravitational instability of molecular gas by Mgas/Mdyn ratio, which can be related to the Toomre's Q value. This also allows us to assess the ratio of rotation velocity and velocity dispersion V_rot/v_sigma, which is a measure of the disk thickness. In addition, we will be able to map the distribution of dust continuum and probably dense molecular gas traced by CS(5-4), which put further support for the nuclear starbursts associated with the heavily obscured AGNs. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-11-21T08:21:43.000 |
| 685 | 2021.1.01365.S | 29 | An ALMA Detailed Polarization Survey of Magnetic Fields within Filaments in a Magnetized Giant Molecular Cloud | Polarization surveys of molecular clouds indicate that cloud-scale magnetic fields influence the formation of filaments and dense cores. However, the role of magnetic fields within filaments and cores is still largely unknown because of the difficulty of making large polarization maps with interferometers, and because single-dish polarimeters are sensitive to both low- and high-density dust along the same sightline. Here we propose a comprehensive study of the two highest column density regions within the Vela C giant molecular cloud. We will make the first ALMA Band 6 polarization mosaic maps of magnetic fields within filaments and directly link our observations to (a) cloud-scale magnetic fields measured by an extremely sensitive balloon-borne polarimeter, and (b) filament scale magnetic fields traced by APEX at 870 microns and SOFIA/HAWC+ at 79/214 microns. Our proposed observations will trace the magnetic field from 0.006pc to 50pc. By measuring the orientation of the field direction relative to cloud structure on different size scales, we will determine the dynamical importance of the magnetic field in different density regimes and feedback environments within Vela C. | Intermediate-mass star formation | ISM and star formation | 2023-10-21T19:38:55.000 |
| 686 | 2017.1.00029.S | 0 | An ISM Rosetta Stone for the Early Universe | The ALMA observations of the z=3.04 Herschel galaxy SDP 81 revealed a collapsing disk containing a galaxy-building starburst. However, the ALMA high-J CO observations were only sensitive to hot dense gas and also missed the more than third of molecular gas that is CO-dark. To obtain a full picture of the ISM in high-redshift galaxies, it is essential to observe lines that sample all phases of the ISM. In the redshift range 4 | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-01-02T14:54:22.000 |
| 687 | 2016.1.00571.S | 125 | Demographics of Grain Growth in the Lupus Protoplanetary Disks | Millimeter multi-wavelength observations of protoplanetary disks allow us to probe the level of grain growth in protoplanetary disks by measuring the spectral index of the continuum emission. Extensive surveys of the Taurus and Ophiuchus star forming region have not shown evidence of the evolution of grains with age: all disks seem to host a population of large grains. The few measurements available for the Lupus star forming region show tantalizing evidence for a different picture, which need to be confirmed. We propose to build on our ALMA Cycle 2 and VLT/XShooter extensive surveys of the Lupus population of protoplanetary disks and conclusively prove (or disprove) the possible evidence for a different grain population in Lupus. Our simulations show that by observing with ALMA the continuum emission at 3mm of 36 Lupus disks (already observed in ALMA Band 7) we will have a sample of measurements large enough to conclusively settle the issue. | Disks around low-mass stars | Disks and planet formation | 2017-11-21T20:14:04.000 |
| 688 | 2013.1.00546.S | 14 | The Explosive Orion OMC1 Outflow | The explosive Orion OMC1 outflow in the nearest site of active massive star formation (D~414 pc) may have been triggered by the dynamic ejection of massive stars ~500 years ago. The proposed 1" resolution ALMA J=CO 2-1 mosaic will measure the mass and momentum of gas in near-IR shock-excited fingers protruding form the explosion site. 1.3 mm continuum and molecules will be used to search for dense high-velocity (>100 km/s) clumps expected at the [FeII]-bright fingertips, to measure the masses of dozens of proto-planetary disks in the foreground Orion Nebula and embedded protostars in OMC1, and to trace the 1.2 mm dust and free-free continuum in the field. The goals are: * Search for dust and measure radial velocities and masses of clumps in the fingertips. * Measure the mass, momentum, and structure of the gas along the H2 wakes. * Determine the masses of the circumstellar disks surrounding in dozens of YSOs. * Probe the relation between the ~500 year old OMC1 outflow and the 10" long, 200 year old flow from source I. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2016-02-25T15:16:30.000 |
| 689 | 2017.1.01163.S | 250 | ALESS CO: A CO survey of spectroscopically-confirmed, ALMA-identified SMGs | The high-redshift galaxies selected at submillimeter wavelengths (SMGs) are amongst the most dusty and active systems in the Universe, with star-formation rates exceeding a few hundred solar masses per year. The fuelling and triggering of their extreme star-formation rates is not well understood, with conflicting models and few observational constraints. Here, we propose a survey of the gas in SMGs, by observing CO in 19 ALMA-identified SMGs with secure rest-frame UV/optical spectroscopic redshifts from the ALESS survey. These observations directly trace the star-formation fuel and will ~double the number of SMGs with high-quality sub-arcsec resolution CO maps. We will use the data to measure the mass and spatial extent of the gas reservoirs in SMGs, properly placing them on the Kennicutt-Schmidt relation. We will also determine whether the prolific star-formation rates are merger-triggered, by measuring the gas dynamics and identifying whether the blends in single-dish surveys are physical associations. Finally, we will use the data to measure the bright-end of the CO luminosity function at high-redshift, which differs by factors of ~10 in different galaxy evolution models. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2019-02-26T14:50:12.000 |
| 690 | 2016.1.00215.S | 32 | Determination of the 12C/13C isotopic ratio in the nearby starburst galaxy NGC 253 | The knowledge of 12C/13C isotopic ratio and its spatial variation are important because 12CO and 13CO are the most and the second most abundant molecules and their line ratio provides important information to constrain physical state of molecular gas. In our galaxy, there is a systematic gradient in the 12C/13C ratio across in our galaxy; from 24 at the center to 70 at 12 kpc, whereas reported 12C/13C ratios in external galaxy centers are higher values of > 40. In order to understand the discrepancy of the central 12C/13C ratio between our galaxy and external galaxies, we propose the optically-thin 12CN(N=1-0) and 13CN(N=1-0) emission observations toward the disk of the gar-rich starburst galaxy NGC 253. If there exists a radial gradient in the 12C/13C ratio within the disk of NGC 253, the 12CN(N=1-0)/13CN(N=1-0) increases from the center to the bar, and the spiral arm. In contrast, if the exists no radial gradient in the 12C/13C isotopic ratio, 12CN(N=1-0)/13CN(N=1-0) shows a constant value of ~50 regardless of the position in NGC 253. We will obtain a new insight a new insight of the 12C/13C isotopic ratio in external galaxies, and will expand such a study to other galaxies. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2018-03-09T23:17:02.000 |
| 691 | 2019.1.00393.S | 26 | Physical Conditions of the Young HL Tau disk | Growing numbers of observations suggest that the first steps of planet formation may be well underway when the disk is still surrounded by an infalling envelope. The fundamental physical conditions inside young embedded disks are still highly uncertain, especially on the gas mass distribution and thermal structure. The HL Tau disk is one of the youngest disk candidates for planet formation. We have carried out pathfinder observations of C18O/C17O/13C18O (2-1) lines (2" resolution) towards the HL Tau disk and determined that 13C18O is the only optically thin tracer of the disk. Here we propose ALMA to spatially resolve the 13C18O/C17O (3-2) lines of the HL Tau disk at 0.3" resolution to trace its gas mass distribution and the radial temperature structure. These observations will provide crucial data that can constrain physical conditions inside the best-studied early disk and demonstrate whether physical conditions in early disks are significantly different from those in Class II systems. | Disks around low-mass stars | Disks and planet formation | 2021-04-21T21:49:24.000 |
| 692 | 2019.2.00169.S | 60 | Molecular gas in HI eXtreme galaxies | We propose to observe the molecular gas content (CO (1-0) line emission) of 6 of the most atomic hydrogen (HI) rich galaxies in the Southern Hemisphere (HIX galaxies). Previous analyses of these galaxies showed that they tend to reside in high-spin halos and are thus able to maintain and support large and extended HI discs. As they have larger HI discs compared to their stellar masses but form stars at an average rate typical for their stellar masses, they appear very inefficient at forming stars. However, the step between HI and star formation is the formation of molecular gas. In order to understand whether these galaxies are inefficient at forming molecular gas from HI, or they are inefficient at forming stars from molecular gas, it is vital to obtain spatially resolved observations of their molecular gas content. Combining the proposed observations with the available HI, UV and IR data, we will be able to compare the atomic gas column density to the molecular gas column density to the local star formation activity and thus understand how increased halo spins affect the gas-star formation cycle. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-04-27T16:17:36.000 |
| 693 | 2019.1.00183.V | 0 | Imaging Jet and Magnetic Field near the Spinning SMBH in M87 | Understanding the jet formation in supermassive black holes (SMBH) is one of the central quests in modern astrophysics. The radio galaxy M87 contains the nearest and largest active SMBH, offering the best opportunity to probe the site of jet launching and propagation near a SMBH. We propose an ultra-deep full-polarization observation of M87 with GMVA+ALMA at 3mm, in order to image the global jet and magnetic field structure around the SMBH on ~7-150 Schwarzschild radii scales in conjunction with Event Horizon Telescope (EHT) observations at 230GHz in Spring 2020. We aim to: (i) distinguish between high/low magnetization jet launching models, (ii) constrain the BH spin using the transverse jet brightness profile, and (iii) find firm evidence for magnetic jet launching in M87 through measurement of the B-field helicity. Combination of previous GMVA+ALMA Cycle 5 and new Cycle 7 data will robustly identify persistent features in the jet against temporal variability. Therefore, the proposed GMVA+ALMA imaging will decisively associate the horizon-scale structures seen by the EHT to the larger-scale jet, completing our understanding of how jets are connected to the central object. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-07-11T16:04:06.000 |
| 694 | 2012.1.00317.S | 58 | Gauging Deeply Hidden Nuclei of Arp 220 | [This project asks for ~120 min of on-source time on Arp 220. See Tech. Justification.] We propose high-precision measurements of putative Compton-thick AGN/starbursts in the nearest ultraluminous infrared galaxy Arp 220. We will use the new 1 km baseline to measure the ~0.1" sizes and ~100 K surface brightness temperatures of the twin nuclei at their dust photospheres. We will then obtain the bolometric luminosity generated within the ~50 pc submm-thick core of each nucleus using the Stefan-Boltzmann law. The dynamical masses of the nuclei will also be measured using Doppler velocities of molecular lines from around the nuclei. The luminosity-to-mass ratios and luminosity densities measured this way will constrain the nature of the luminous nuclei because these parameters have lower upper limits for starburst than for AGN. In addition, the highest-ever resolution in the submillimeter observations toward the merger is expected to reveal non-trivial shape, structure, gas motion including outflows, and extreme ISM properties of the nuclei. Our observations will make initial steps of comprehensive ALMA studies on merger-induced evolution of galaxies and their activities. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2017-01-22T16:30:55.000 |
| 695 | 2012.1.00394.S | 13 | Revealing the Evolutionary Status of Candidate First Cores | In the low-mass star formation process, the first hydrostatic core is a short-lived object in hydrostatic equilibrium between thermal and gravitational pressure. It forms out of a dense molecular cloud core when the initial collapse transitions from isothermal to adiabatic. This phase lasts until the temperature rises to 2000 K and molecular hydrogen dissociates. First cores were predicted theoretically over 40 years ago but have not yet been conclusively identified by observations. Recently, several promising candidates have been suggested, but none are well-characterized enough to reveal their true evolutionary status. We propose to obtain ALMA band 3 observations of a suite of dense gas tracers toward all 5 recently identified first core candidates in order to study their physical properties, density structure, kinematics, and chemical structure, and ultimately to reveal the true evolutionary status of these intriguing new objects. | Low-mass star formation | ISM and star formation | 2015-05-06T00:00:00.000 |
| 696 | 2016.1.00478.S | 42 | Size matters: resolving the rest-frame far-infrared-emitting region of submillimetre galaxies in the COSMOS field | Recent ALMA studies suggest that the dust-emitting sizes of submillimetre galaxies (SMGs) are ~2-4 times smaller than their radio sizes. This is surprising because both the dust and radio emissions are thought to reflect the spatial extent of active star formation. However, the aforementioned studies are based on different samples that lack the source-by-source (sub)mm and radio imaging data. To further test the possible dust-radio size discrepancy among SMGs, we propose to use ALMA to perform 870 micron/0.2" resolution imaging of a unique sample of 41 SMGs in COSMOS that are drawn from our Cycle-2 1.3 mm continuum survey. This is paramount to i) derive the FIR sizes of our SMGs that already have radio sizes from the deep, VLA-COSMOS 3 GHz data at 0.75" resolution; ii) study the multiplicity of SMGs in S/N-limited samples on <1" scales, which is crucial for accurate source count determinations constraining galaxy formation models; and iii) identify merging systems and thereby test the Taffy-system hypothesis as an explanation for the dust-radio size discrepancy. Overall, the proposed study will significantly push our understanding of SMGs and their role in massive galaxy evolution. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-11-22T19:27:09.000 |
| 697 | 2017.1.01671.S | 25 | Molecular outflow in the center of NGC 613 | We propose to observe the central region of the nearby galaxy NGC 613 (17.5 Mpc) in CO(1-0) with 0.1" (8.5 pc) resolution. Through an ALMA cycle 2 program, we found that the gas in the circum nuclear disk (CND) is mainly heated by the jets. We also found signs of a molecular outflow along the jets with the CO(3-2) observations. Although the distribution and dynamics of the outflow are likely explained by a jet-driven model, the bulk feature of the outflow is still unclear. The proposed CO(1-0) observation will reveal the bulk of the outflow and the relation between the jets and the outflowing and inflowing gas. The angular resolution of 0.1" will allow us to resolve the CND. From the dynamics of the CND, we shall estimate the gas speed inflowing to the center and dynamical mass of the inner region of the CND. We reveal whether or not the outflow is interacting with the CND and derive the outflow molecular mass and outflow rate. Based on the physical conditions of molecular gas we have already derived, we will reproduce the dynamics of the outflowing gas and the CND with 3D relativistic hydrodynamical simulations of jets propagating into a clumpy disk. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-01-04T23:10:33.000 |
| 698 | 2016.1.01520.S | 40 | Spiral Structure and Clump Kinematics in the Gravitationally Unstable Disk Around L1448 IRS3B | ALMA Cycle 2 observations toward the triple protostar system L1448 IRS3B have yielded a tantalizing discovery of a fragmenting circumbinary disk with spiral structure. This source shows direct observational evidence for disk fragmentation actively taking place and our analysis indicates that the disk itself is still marginally unstable. The previous observations, however, did not resolve the inner circumbinary disk, nor the origin point of the detected spiral structure. Furthermore, the current C18O and 13CO observations are unable to characterize the kinematics of the widely separated (200 AU) protostellar clump, relative to the circumbinary disk. Thus, to better understand the origins of the spiral structure and clump kinematics, we propose ALMA continuum observations at 870 micron and 0.11" resolution, while simultaneously probing gas kinematics with the rarified C17O isotopologue and the high-density tracers H13CO+ and H13CN. | Low-mass star formation | ISM and star formation | 2018-01-14T00:24:40.000 |
| 699 | 2012.1.00631.S | 3 | Non-Axisymmetry in the Gapped Protoplanetary Disk around HD 142527 | The protoplanetary disk around HD 142527 is one of the best and unique sites to investigate disk-planet interaction as well as disk clearing mechanism in ALMA Early Science. As has been uncovered by our previous studies in near-infrared and submillimeter, (1) the disk has a large gap extending to about 1 arcsec from the star, and (2) it shows a strong non-axisymmetry including the eccentric gap, arm-like structures, and density enhancement in the northern area. We therefore propose the high-angular-resolution (0.2", 30 AU) observations for HD 142527 of optically thin 13CO(3-2), C18O(3-2) lines and dust continuum using the most extended antenna configuration in Band 7. Our primary focus is to probe any asymmetry/inhomogeneity in density/velocity structure inside and outside of the gap, while keeping the high sensitivity to detect gas and dust depleted by a factor of about 50 in the gap relative to the outer disk. The proposed observations can reveal the detailed disk structure both in gas and dust in submillimeter for the first time, which will be valuable to understand the dynamical interaction with a possible planet in the eccentric gap. | Disks around low-mass stars | Disks and planet formation | 2016-10-29T21:27:06.000 |
| 700 | 2017.1.00986.S | 18 | Constraining Ultracool Dwarf Radio Emission Mechanisms and Implications for the TRAPPIST-1 Planetary System | We propose to observe the M star TRAPPIST-1 with ALMA in Band 3 to constrain the millimeter emission mechanism and to investigate the stars effect on the its planetary system through, e.g., the acceleration of energetic particles, which can have a substantial effect on planetary atmospheres and habitability. The immediate objectives of this work are to (1) determine TRAPPIST-1s flux density at 97.5 GHz, which will be used to measure the stellar radio emission mechanism at high frequencies; (2) constrain the magnetic field strength and electron energy densities in the stars upper atmosphere; (3) explore the poorly understood millimeter wavelength flux spectrum of ultracool M stars; and, (4) characterize the strength of radio flares in the system should one occur during the observations. We expect this system to be a high value target for JWST and future observations characterizing the habitability, so observing its behavior at multiple wavelengths is of particular interest to understanding the star and its surrounding environment. | Exo-planets | Disks and planet formation | 2019-03-23T14:59:27.000 |
| 701 | 2015.1.00022.S | 13 | High spatial resolution imaging of the inner envelope of R Sculptoris | We propose to observe the detailed structure of the spiral shape detected in Cycle 0 observations in CO line emission around the carbon AGB star R Scl. A succesfull Cycle 1 proposal (carried over to Cycle 2) was aimed at observing the circumstellar emission from R Scl at high angular resolution in CO emission in band 7. The proposal combines the most extended main-array configuration for high spatial resolution with a compact main array configuration, ACA and total power observations. The data will describe the detailed inner circumstellar morphology by measuring deviations from a perfect spiral, resolving the binary system, and accurately measuring the contrast between the winding and inter-winding regions, relying on the high angular-resolution observations. The Cycle 1 low-resolution data confirm the Cycle 0 findings. However, the extended configuration has not yet been observed. Missing the high-resolution data will limit the value of the delivered Cycle 1 observations. We therefore resubmit the observations for the extended configuration (a total observing time of approx. 1 hour). In case the data is still completed in Cycle 2, we will withdraw the Cycle 3 proposal. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2018-02-03T22:24:20.000 |
| 702 | 2015.1.00530.S | 164 | An ALMA-MUSE Survey of Extended Radio Galaxy Haloes | Recent VLT/MUSE observations of the extended (>100 kpc) gaseous haloes surrounding high-redshift radio galaxies have revealed a very complex structure of ionized and neutral gas. A comparison with our snapshot ALMA Cycle 1 + 2 dust continuum imaging shows that the star-formation in these haloes can be offset by as much as 80 kpc from the central AGN. We here propose matched resolution ALMA [CI](1-0) imaging of a sample of seven radio galaxies at 2.9 | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-05-12T23:22:57.000 |
| 703 | 2016.1.00635.S | 34 | ALMA Resolves An Extra-Planar Molecular Outflow | Outflows resulting from stellar feedback play a key role in shaping the evolution of galaxies. While the nuclear starburst-driven outflows found in galaxies like M82 and NGC 253 are spectacular examples of outflows, disk-wide outflows may be responsible for moving large amounts of gas into the halos of typical galaxies. The best such example of latter type of system is NGC 5775. This galaxy has a disk-wide outflow with low resolution molecular gas detections at high latitudes. We propose to use ALMA Bands 3 and 7 to obtain the first high resolution maps of the molecular gas traced by 12CO(1-0) and 12CO(3-2) in NGC 5775. Our high resolution ALMA CO observations will allow us to quantify the extent, kinematics, and energy of the molecular gas in an outflow-driven extensions far from the nucleus and compare these quantities to those found in other key components of the interstellar medium including ionized gas, cosmic rays, magnetic fields, and neutral hydrogen (HI). These measurements will allow us to test the hypothesis that disk-wide outflows are important for the shaping the evolution of galaxies in the best such example of this type of system. | Spiral galaxies, Outflows, jets, feedback | Local Universe | 2018-02-28T04:26:27.000 |
| 704 | 2023.1.00675.S | 0 | Magnetic fields and triggered star formation in the photoionization fronts of the Pillars of Creation | We propose to make the first interferometric measurements of the magnetic field geometry in the star-forming regions at the tips of the "Pillars of Creation" photoionized columns. We request 3.0 hours of ACA array time to observe the dense cores in the tips of the two brightest columns in Band 7 full polarization. The Pillars, famously imaged by the Hubble Space Telescope, are a potential site of ongoing triggered star formation. Recent JCMT observations show that the magnetic field of the Pillars runs along their length, but cannot resolve the field geometry in the pillar tips, where the interaction with the ionization front driven by the nearby NGC6611 cluster is taking place. The interaction between magnetic fields and feedback effects may play a key role in regulating star formation, making it necessary to map such interactions on the scales of individual cores evolving under intense stellar feedback. Observing the dense cores in the tips of the Pillars in ACA full polarization will allow us to investigate the interaction of magnetic fields with ionization fronts, and to investigate the role of magnetic fields in the triggered star formation paradigm. | High-mass star formation, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 3000-01-01T00:00:00.000 |
| 705 | 2019.1.01804.S | 402 | A GEMS CO follow-up survey of IC 1459 group and NGC 4636 group | Galaxy groups are the place where many galaxies feel the impact of the surroundings for the first time before joining bigger structures. GEMS is a panchromatic survey of 60 selected nearby galaxy groups to study environmental effects on galaxy evolution in the group environment, using a broad range of wavelengths from radio, optical, ultraviolet and X-ray. One missing dataset is the cold molecular gas, which plays a pivotal role in understanding the details of change of star formation activity in the group environment. Therefore, we propose to obtain high-resolution CO (1-0) images of the GEMS sample, starting with 18 galaxies in IC 1459 and 22 galaxies in NGC 4636, using the ACA. We selected all the targets that have been detected in the GEMS-HI survey, making the sample of 40 in total. Using the high-resolution CO data, we will probe the morphological and kinematical characteristics of the molecular gas as well as the resolved Kennicutt-Schmidt law in the group environment. We will also compare the properties of our sample between the two groups as well as with those of cluster members. To image 40 GEMS galaxies in 12CO (1-0), we request 37 hours of the ACA time in total. | Merging and interacting galaxies, Galaxy groups and clusters | Galaxy evolution | 2021-01-29T21:52:14.000 |
| 706 | 2012.1.00333.S | 0 | Outflows of metal-poor evolved stars in the globular cluster 47 Tuc | How do metal-poor, oxygen-rich evolved stars lose mass, and how much mass do they lose? The major missing clues to answering these questions are the gaseous mass-loss rates and expansion velocities of their winds. We can obtain these by spectrally resolving the CO (2-1) and (3-2) lines of four well-studied evolved stars in the globular cluster 47 Tucanae. Combining these observations with known stellar and wind parameters, derived from optical spectroscopy and infrared dust observations, we can directly yield the outflow velocity and total mass-loss rate of each star. With this information, we can begin to unravel the processes that control and drive mass loss from these stars. We can also explore how stellar luminosity and the strength of stellar pulsation affect conditions in low-metallicity stellar winds. The lack of existing data on the subject means these observations can have a direct and profound impact on models of stellar evolution, galactic ecology, and chemical enrichment in metal-poor systems, including the early Universe. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-03-18T00:00:00.000 |
| 707 | 2013.1.00940.S | 5 | Interstellar rust -- confirmation of the first iron molecule in the ISM | The very high sensitivity of ALMA makes it possible to detect species which have very small column densities, and are utterly out of reach of other instruments. Of particular importance are molecules containing refractory species (mostly metals in the common-usage sense of the word), which normally are locked up in grains. While ubiquitous in circumstellar envelopes, molecules containing refractory species (notably Si) are only detected in the ISM when grains are destroyed, either by shocks or energetic photons. The only species that has tentatively been detected beyond silicon is FeO, of which one line was found in absorption toward SgrB2(M). Here, we would like to confirm this detection by looking for higher excitation lines, and lines of a rare isototopologue. Should this be successful, this would open the road to a whole new line of research of investigating the physics of dust processing in shocks by determining the abundances of iron, magnesium etc. bearing molecules. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-12-23T16:50:48.000 |
| 708 | 2022.1.00072.S | 10 | Active Nuclei tori and outflows traced by CI | In recent years ALMA has revealed the presence of molecular tori of typical 10pc-scale radius in nearby Active Galactic Nuclei (AGN). These molecular tori are kinematically decoupled from their galaxy disk, and are often accompanied by molecular outflows, triggered by the AGN. The tori are clumpy and may be tilted, warped and turbulent. Both tori and outflows could produce the obscuration required in type 2 AGN, but currently it is impossible to disentangle them near the AGN. To increase the spatial resolution, and follow the AGN fueling/feedback further in, other tracers must be probed. The CO molecules are progressively destroyed to the benefit of atomic carbon CI, in the X-ray dominated region close to the AGN. We propose to map in CI at higher resolution (0.05''=4, 2, 14 pc) than before the gas and dust emission in three nearby AGN, which have high X-ray luminosity. Our goal is to better trace the morphology and kinematics of the torus, quantify the fueling and feedback processes. We will determine the origin of molecular outflows, better traced in CI, and confront the observations to models. The higher resolution will also permit a more precise and accurate black hole mass. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-07-31T00:00:00.000 |
| 709 | 2018.1.01561.S | 37 | Multi-frequency Observation of a Forming Massive Binary | Binarity is considered to be one of the essential features to understand massive star formation. Little is known about the inital status of massive binaries during their formation while they are still highly embedded and accreting. We propose ALMA Band 3, 8 and 10 continuum and hydrogen recombination line (HRL) observations with high angular resolution (0.03-0.05 arcsec, i.e. 50-80 au) toward IRAS 07299-1651, which is a massive protobinary system with a separation of 180 au discovered by our previous ALMA band 6 observation. However, the band 6 observation is not sufficient to accurately estimate the mass and other properties of the system, due to the fact that both free-free emission from the ionized gas and dust emission from the molecular gas contribute to the continuum emission. The proposed observations, after combining with our previous Band 6 data, will provide a full coverage of the SED and HRLs from ~0.3 mm to ~3 mm, allowing us to estimate the properties of the ionized gas and dusty molecular gas, to further constrain the properties of the massive protobinary and its surrounding gas, including their circumbinary disk and individual circumstellar disks. | High-mass star formation, HII regions | ISM and star formation | 2020-11-17T00:00:00.000 |
| 710 | 2011.0.00320.S | 0 | Dispersal of protoplanetary disks: study of suspected gas-poor dusty-rich sources | Understanding how protoplanetary disk dissipates is an essential step towards the comprehension of the planetary system formation process. Young pre-main sequence stars surrounded by gas poor, but dusty rich disks may hold one of the clues towards this step. We propose here to accurately constrain the CO column density and temperature distribution in three objects which are suspected to be in such a phase: BP Tau, CQ Tau and MWC 758. Accurate CO column density measurements, obtained by a combination of multi-line 12CO study and sensitive 13CO J=3-2 observations, will prove the low CO content of these disks. Temperature measurements should unambiguously confirm their suspected warm nature, and dismiss depletion on dust grain as the cause of low CO abundance. | Disks around low-mass stars | Disks and planet formation | 2014-05-10T18:15:00.000 |
| 711 | 2015.A.00022.T | 30 | Measuring the Luminosity of an ALMA Detected Accretion Event in the Massive Protostellar Cluster NGC6334I | Our Cycle 2 observations of NGC6334I at 3 and 1.3~mm have revealed that one member of this massive protocluster, MM1C, has increased its dust emission by a factor of >4 compared to earlier observations with the SMA at 0.87~mm and the VLA at 7 mm. This increase suggests an episodic accretion event in which the luminosity has increased by a factor of >140. It is critical to observe it again as soon as feasible in order to constrain the variability timescale and luminosity. We choose Band 7 because it is the only wavelength for which we have a pre-burst detection (SMA, 0.87 mm), and dust is the dominant emission mechanism for this source (non-detection at 7 mm). For an accurate measurement, we need sufficient angular resolution (<0.2'') to resolve MM1C from the other cluster members and match our existing 1.3~mm ALMA data. Fortuitously this is attainable by the current and remaining configurations of Cycle 3. To our knowledge this is the best observational evidence of episodic accretion in a high mass protostar to date; the verification of such a large, rapid ( | High-mass star formation | ISM and star formation | 2017-03-01T17:30:43.000 |
| 712 | 2016.1.00994.S | 113 | Validating the L850-MH2 calibration with Herschel-ATLAS galaxies up to z~0.4 | Disentangling the physical processes contributing to the decline in the cosmic star formation rate requires the measurement of the interstellar gas content of galaxies out to high redshift, but CO line observations are difficult and time-consuming. The development of a calibration between the dust continuum luminosity at 350 GHz (lambda = 850um) and the molecular gas content provides a more efficient method to infer the gas mass of high redshift galaxies, yet current measurements of the Lv850/MH2 ratio rely on small samples of star-forming galaxies. How this ratio varies with other galaxy properties remains unknown. We thus propose to use 6.7 hrs of ALMA Band-6 and Band-7 to observe the dust continuum at 350 GHz to an rms of 0.2 mJy/beam, simultaneously tracing the CO(J=3-2) line emission at 346 GHz, for 49 galaxies selected from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). With this large sample, we aim to (i) confirm the Lv850/MH2 ratio found in previous studies, (ii) identify any physical properties affecting the shape or scatter in the calibration, and (iii) provide to the community a robust calibration for applying to higher redshift observations. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2018-04-17T18:13:08.000 |
| 713 | 2013.1.00252.S | 4 | The massive, fast-bipolar outflow of the extreme AGB star OH231.8+4.2 | One striking aspect of the late evolution of Sun-like stars is the sudden change in morphology of the circumstellar gas from the asymptotic giant branch (AGB) to the planetary nebula (PN) phase. On the AGB, the stellar mass loss is roughly spherically symmetric, but this rapidly evolves into prominent non-spherical morphologies in the proto-PN phase. There is a small class of objects that show well developed PPN-like morphologies but have AGB central stars. The prototype of this small class of objects is OH231. We propose to map with unprecedented spatial resolution (0.24") and sensitivity its bipolar molecular outflow, where the effects of the recent collision between jets and the dense AGB wind are notable. We request a 5-point mosaic of the 12CO J=3-2 (and, simultaneously, 13CO J=3-2 and CS J=7-6) emission, and one single-pointed map of the CS J=6-5 line. We aim to constrain the mass and temperature stratification and the velocity field along and across the lobes. CO transitions are the best tracers of the bulk of the envelope (predominatly cold, 10-40K). The CS J=6-5 line selectively traces warm (~200K) gas discovered by us from low (~8"-40") angular-resolution observations. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2018-05-01T00:00:00.000 |
| 714 | 2023.1.01720.S | 0 | The molecular ring orbiting Sgr A*: a small promising site of star formation | There is significant observational evidence pointing to probable star formation occurring in the understudied region called the NE Arm of the Galactic Circumnuclear Ring (CNR). This region has received little attention before but is now of interest due to multiple observations of molecular lines that trace star formation, including a submm continuum source. The radiation and tidal effects of the central supermassive black hole have minimal effects here, and there are observed molecular densities above the Roche-limit, suggesting star formation in the region. We intend to conduct a joint VLA/ALMA project to observe high frequency continuum, SiO, 13CO, and methanol emission towards the NE Arm. With the VLA we will search for ultra-compact HII regions in the high frequency Q-band continuum and methanol emission tracing outflows, while our ALMA observations will search for compact dust continuum sources in addition to jets traced by SiO and 13CO. These observations have not been conducted previously for the region, and the discovery of hot cores or ultra-compact HII regions would provide definitive proof of star formation in the NE Arm. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-08-01T21:38:46.000 |
| 715 | 2017.1.00571.S | 70 | Toward the Baryon Census of z~0.3 Galaxy Groups | Galaxy halos appear to be missing approximately 60% of their baryons, most probably hiding in the circumgalactic medium (CGM), a diffuse component within the dark matter halo that extends far beyond the inner regions of galaxies. A powerful tool to study the CGM is offered by absorption lines seen in the spectra of background quasars. To establish the connection of the CGM gas probed to the underlying galaxy, it is essential to complement the absorption spectroscopy with imaging of the galaxies. A powerful technique is 3D spectroscopy. Using VLT/MUSE, we have successfully detected multiple galaxies associated with N(HI) absorbers. Thanks to ALMA cycle 4 observations, we are able to measure the H2 masses, velocity fields and star formation efficiencies of four CO(1-0) sources in one of these fields. Capitalising on this powerful synergy of MUSE and ALMA, we propose to target the remaining absorbers. We request band 6 observations to observe the CO(3-2) molecular gas in galaxies identified with MUSE at z~0.3. These structures are ideal to relate the neutral atomic gas, molecular gas and stars in the same galaxy groups resulting in a full baryon census of complex galaxy structures. | Damped Lyman Alpha (DLA) systems | Cosmology | 2019-07-23T17:06:29.000 |
| 716 | 2016.1.00878.S | 1 | Who Stirs the Pot? Resolving the Vertical Thickness of Debris Disks | The dusty debris disks around main sequence stars are hallmarks of substantial reservoirs of large planetesimals. Edge-on debris disks present a unique opportunity to characterize the dynamics of the collisional cascade, since the vertical scale height encodes the velocity dispersion and allows us to measure the total mass of any perturbing bodies "stirring" the planetesimal belt. Millimeter wavelengths are uniquely suited for revealing the dynamical state of debris disks, since the large grains are not subject to the excitatory effects of stellar radiation that puff up the vertical scale height at optical and infrared wavelengths. Here we propose to complement our recent high-resolution Band 6 observations that spatially resolved the scale height of the AU Mic disk for the first time by making the same measurement at Band 9. Resolving the vertical structure at two widely separated frequencies will allow us to constrain both the grain size distribution and the velocity dispersion as a function of particle size. For the first time, we will be able to distinguish the strengths of the bodies in the collisional cascade. | Debris disks | Disks and planet formation | 2018-05-26T18:05:55.000 |
| 717 | 2017.1.00725.S | 17 | Resolving the Radio Core of Eta Carinae | Eta Carinae is an LBV star forming part of a high mass binary system. The objective of this project is to map the region that emits at submillimeter wavelengths, in the continuum and in the H30 alpha recombination line, using band 6. The region was observed with ALMA in Cycle 0 but was not resolved, even at the highest frequency (630 GHz, resolution 0.45x0.32 arc sec). The integrated continuum spectrum (between 100 and 630 GHz) is characteristic of a compact HII region that becomes optically thin around 250 GHz and H and He recombination lines showed signatures of departure from local thermodynamic equilibrium. From these observations and assuming a spherical expanding shell with constant electron density and temperature, we were able to determine univocally the radius, shell width, density, temperature, and expansion velocity. The radius of the shell is about 0.2 arc sec, and its width a tenth of this value, which makes it possible to resolve with ALMA in its extended Cycle 4 configuration. Depending of the image of the ionized emitting matter, its origin can be attributed to an LBV ejection episode or to the concentration of shocked matter produced in the wind-wind collision. | HII regions | ISM and star formation | 2020-06-26T16:27:32.000 |
| 718 | 2016.A.00021.T | 33 | A forming-planet in the debris disk of HD95086? | This DDT ALMA proposal aims to reveal the nature of a new millimeter bright compact object located within the debris disk of HD95086. This new object was revealed by Cycle 2 ALMA observations. This 1.3 mm continuum source could likely be a young major planet that is just forming in the outskirts of its debris disk or maybe a background submillimeter galaxy. To elucidate its nature, we request more high sensitivity, high angular resolution ALMA observations at different wavelengths. If the new ALMA observations validate the possibility of having a forming-planet in HD95086, the discovery could be a breakthrough in the area of planet formation. We emphasize that given the very low declination of HD95086 ($\sim$ -70$^\circ$) and the tremendous sensitivity of ALMA and spatial resolution, this project cannot be done with any other (sub)millimeter observatory. | Exo-planets | Disks and planet formation | 2017-11-05T19:26:00.000 |
| 719 | 2023.1.00874.S | 0 | The most comprehensive survey of dense gas in high-z galaxies | We request 25 hours of ALMA Band 1 observations to conduct the largest-ever survey of dense gas tracers (HCN, HCO+, HNC) in high-z dusty star-forming galaxies (DSFGs). While high-z galaxies have been extensively studied in molecular gas (via CO and [CII]) and obscured star formation (dust continuum), the link between these two - their dense gas (>10^4 cm-3), typically traced by HCN, HCO+ and HNC - is almost completely unexplored. Recent studies suggest that high-z DSFGs are surprisingly lacking in dense gas while having significantly elevated star-forming efficiencies. However, these claims are based on a handful of galaxies, most of which are non-detections. To understand the star-forming processes in DSFGs, it is necessary to move to larger samples and robust detections. We propose deep observations of the Jupp=2 transitions of HCN, HCO+ and HNC in ten strongly lensed galaxies from the SPT sample. By measuring the dense-gas content in the largest-ever sample of high-z galaxies to an unprecedented depth, this project will gather more data than all the previous dense-gas studies combined, providing the first clear view of dense gas in high-redshift galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2025-03-20T10:23:17.000 |
| 720 | 2018.1.00747.S | 6 | Understanding high-redshift star-formation on 100-pc scales | Dusty, star-forming galaxies (DSFGs) are a main contributor to the SF activity at z=2-4. However, the processes behind their intense SFR and properties of their ISM remain poorly understood due to the lack of multi-tracer, high-resolution studies. A strongly-lensed z~3 galaxy SDP.81 is the best-studied representative of the DSFG population. With >40 hours of ALMA high-resolution imaging, SDP.81 provides a unique view of high-z molecular gas and dust on 100-pc scales. However, to properly constrain the ISM conditions, matched-resolution observations of low-J CO transitions need to be added to the extant data. We request 5 h of Band 3 time to complete our partially-executed Cycle 4 observations of the CO (3-2) line in SDP.81. The CO (3-2) is a key tracer of the cold molecular gas that fuels the star-formation. With our previous reconstructions of the CO (5-4)/(8-7)/(10-9) lines and Bands 4/6/7 continuum, and the recently obtained [CII] data, this project will provide the first maps of the CO ladder in a z>2 star-forming galaxy at 100-pc scales, creating a high legacy value dataset. SDP.81 will then be able to serve as a unique testbed for the models of high-z star-formation. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2022-10-19T22:24:05.000 |
| 721 | 2018.1.00883.S | 23 | Unveiling Absorption-Selected Galaxies with ALMA: an Insight View of the Baryon Cycle at z~2 | The baryon cycle - the cycling of gas into and out of galaxies through the circumgalactic medium (CGM)- plays a fundamental role in galaxy evolution, but has few empirical constraints. The diffuse CGM gas is currently best detected in absorption towards bright background QSOs, but historically the difficulty of selecting foreground galaxies close to a QSO sightline using UV/optical imaging has limited observational progress. ALMA promises to revolutionise this field by enabling the selection of galaxies via their CO rotational lines, free from the biases that limit optical selection. Here we propose to use ALMA to target a single QSO sightline in the Hubble Deep Field South. We aim to link two known z~2 strong absorption systems in the sightline to nearby galaxies. By combining our CO emission observations, the absorption systems, and deep multiband imaging, we will constrain models of the gas cycle in purely absorption selected galaxies and test predictions of current models of galaxy formation. | Lyman Break Galaxies (LBG), Damped Lyman Alpha (DLA) systems | Galaxy evolution | 2020-07-02T18:24:24.000 |
| 722 | 2018.1.00934.S | 909 | The temperature-multiplicity relation with ALMA | Multiple protostellar systems are the most common form of star formation. Simulations suggest that heated gas hinders fragmentation, with only cold gas fragmenting. Once a protostar forms, the gas is quickly heated and further fragmentation is suppressed. Thus gas temperature has a direct impact on multiplicity. A recent survey of 12 Perseus embedded protostellar systems including single and multiple protostars, probed the cloud core gas temperature (~7000 AU) and found no correlation between gas temperature and multiplicity. However, the temperature structure can vary considerably on envelope scales (1000 AU). We therefore propose to observe the same sample of 12 embedded protostellar systems using the stand-alone ACA mode in Bands 6 and 7, targeting DCO+, H2CO and c-C3H2. These molecules trace cold, warm and UV-irradiated gas, respectively, and will produce gas temperature maps. We aim to determine if multiplicity is directly related to gas temperature on envelope scales, and its connection to the gas temperature on cloud core scales. We can determine whether the gas is warm (40K) or cold (<20K) at envelope scales, answering the relation of multiple star formation and temperature | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-12-06T02:48:54.000 |
| 723 | 2015.A.00012.S | 3 | Resolving the accretion structures around the very young protostars B1b-N and B1b-S | We have obtained ALMA long baselines observations towards the very young protostars B1b-N and B1b-S, reaching an angular resolution of 0.05" (12AU at the source distance of 250pc). Both sources are clearly resolved with dense structures of 0.5" - 1" diameter around, smoothly connected with the surrounding envelope. The more evolved source B1b-S shows a more extended structure and a sharper contrast, while the FHSC candidate B1b-N is more compact but has a shallower flux radial distribution, with a shoulder at r ~0.4". This structure is strikingly similar to predictions of MHD simulations, and could trace the emergence of a young disk. In the current ALMA data, a large fraction of the submillimeter flux (~ 1 Jy for each source) is detected at low surface brightness level (0.1 - 1 mJy/beam). Because of the lack of intermediate baselines (50 - 300 m), we do not know the spatial distribution of this semi-extended emission, which traces how the YSOs are fed by the collapsing core. This limits the analysis of the detected structures at radii between 0.5" and 5", and the comparison with MHD simulations. We therefore request additional observations to fill this hole in the UV plane. | Low-mass star formation | ISM and star formation | 2017-02-12T14:08:45.000 |
| 724 | 2022.1.01219.S | 70 | A Spectral Search for Axionic Dark Matter | The axion is a promising dark matter candidate that can also solve the strong CP problem (the lack of a neutron electric dipole). Axions can be converted into photons in the presence of a strong magnetic field, and laboratory experiments to detect axions are underway. But laboratory experiments are limited by magnetic field strength, dark matter flux, and search bandwidth (which equates to axion mass range). Axions can be converted into photons in the magnetospheres of neutron stars, so a spectral line search toward pulsars can detect dark matter axions. The Galactic Center magnetar Sgr J1745-2900 offers the perfect setting for such a search: it has a strong magnetic field and should see the highest possible dark matter flux. We therefore propose to conduct a spectral line search toward this magnetar in Bands 3 and 4. The search will either detect the dark matter particle, solving a decades-long puzzle and revising the Standard Model of particle physics, or it will produce new constraints on the axion-photon coupling parameter, probing theoretical predictions. These observations will be superior to laboratory experiments and require a ralatively minor telescope time investment. | Galactic centres/nuclei | Active galaxies | 2024-05-19T16:40:17.000 |
| 725 | 2018.1.00035.L | 898 | ALMA Lensing Cluster Survey | We propose an extensive survey of 33 clusters to a depth of 0.08 mJy (1.2 mm, 1 sigma). This will be accomplished with a 15-GHz-wide spectral scan, to enlarge the survey volume of line emitting galaxies. The sample comes from the best-studied clusters blessed with HST treasury programs, i.e., CLASH, HFF, and RELICS. We will map the high-magnification regions of these clusters with a total coverage of 88 arcmin^2. The proposed survey is the logical next step after ongoing ALMA-HFF and cluster programs, based on successful ALMA detections of faint continuum sources and line emitter candidates in lensing clusters. In conjunction with the rich ACS/WFC3/IRAC data, we will determine the nature of faint submm galaxies and line emitters. Through the redshift distribution, SFR, stellar and ISM masses of sources that only ALMA can locate and study, we will probe the origin of the extragalactic background light, measure the [CII] luminosity functions near the Epoch of Reionization, and constrain the evolution of the molecular gas mass density up to the peak epoch of cosmic star formation. We will also discover rare highly lensed objects for future follow-up with ALMA. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2020-01-31T09:38:10.000 |
| 726 | 2021.1.00857.S | 69 | Using [OI]63um as a new tracer for the densest gas in lensed dusty star-forming galaxies from the SPT survey | The [OI]63µm line is one of the three brightest fine structure lines in galaxies (together with [CII]158µm and [OIII]88µm), and the only one probing very dense (10^6 cm^-3) neutral gas. Therefore, in a dusty ISM, studying [OI]63µm is the only way to uncover components which may not be associated with standard HII regions or PDRs, such as XDR in AGN or unusually dense, compact star-forming regions, which are suspected to be present in IR-luminous galaxies at high redshift. Despite its brightness and importance, the [OI]63µm line has been virtually unexplored in high-z galaxies, because its rest wavelength requires both sensitive high-frequency receivers and samples of very high z targets. We here propose to exploit the unique combination of ALMA bands 9 and 10, and the sample of distant strongly lensed dusty star-forming galaxies from the SPT survey. Our sample contains 20 objects at z=4.2--5.8 where [OI]63µm is observable with ALMA bands 9 and 10. We already have lensing models and [CII] data for 14 out of 20 sources, and here also request ACA [CII] data for the remaining 6. The [OI]/[CII] ratio will be the ultimate dense gas diagnostic in our sample. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2022-10-05T19:12:25.000 |
| 727 | 2019.1.00189.S | 18 | Unveiling the planetary architecture around the Solar analogue HD107146 | We propose to observe HD107146's debris disc in band 7 to study in detail the radial structure of its disc that extends from 40 to 140au. Previous observations by our group showed that this 100au wide disc has a gap at 80au, which hints at the presence of one or multiple planets formed at tens of AU. Because the gap is 50au wide and has a relative depth of ~0.5, we concluded that it can only be explained by planets if there are multiple low mass planets (<30Mearth) or a single low mass planet migrating through a planetesimal disc. We request new observations with 5au resolution to disentangle these two scenarios. In addition, these new observations will reveal the origin of the inner emission that we found at 15au from the star, which could be due to an inner asteroid belt that is asymmetric. New ALMA observations at the requested sensitivity and resolution will provide unique constraints on planet formation at tens of au around this Solar analogue and definitely confirm that the inner emission belongs to the system, placing tight constraints on the architecture of the outer and inner regions of this system. | Debris disks, Exo-planets | Disks and planet formation | 2022-10-26T09:42:08.000 |
| 728 | 2016.1.01604.S | 468 | A spatially resolved Kennicutt-Schmidt relation for a mass-complete sample of star-forming galaxies at z~1.5 | A relation between the production rate of stars and their neutral hydrogen fuel is in the spotlight of galaxy evolution research. Particularly, the relation between neutral gas and star formation rate surface densities is of interest, given its connection to local free-fall time. Probes of this relation at high redshift -- which critically extent the luminosity span of local galaxy samples -- are observationally expensive if based on CO emission as a tracer for molecular gas. The resulting samples are often not representative for all galaxy populations. While molecular gas probes from CO rely on insecure mass-conversion they are often spatially unresolved, hence relying on (possibly) biased size determination at shorter wavelengths to obtain surface densities. We propose to overcome those biases via spatially resolved monochromatic band-7 observations of 60 mass-selected star forming galaxies in the COSMOS field. Critically, their star forming sizes have been constrained from recently obtained sub-arcsecond resolution VLA imaging. This unique sample will allow ALMA to accurately constrain the Kennicutt-Schmidt relation close to the peak of the cosmic star formation rate density. | Galaxy structure & evolution | Galaxy evolution | 2018-12-18T15:09:29.000 |
| 729 | 2019.1.01636.S | 9 | The Origin of [C II] and [N II] Emission in High-z Dusty Starbursts | Far-IR [C II] 158 micron line and the [N II] 122 & 205 micron lines are important ISM cooling transitions that are becoming popular probes for studying high redshift galaxies as a result of the advent of ALMA high frequency performance (Bands 8, 9, & 10). While they are commonly used as tracers of cold gas and SFR, they both arise in relative low density ionized gas in our Galaxy and nearby galaxies and are subject o complications due to variations in radiation field, metallicity, ionization, and gas accretion/ejection. The physical properties gas emitting these FIR lines are even less well understood. We propose to a high resolution, deep imaging study of 3 strongly lensed dusty star forming galaxies at z=2-3 with the requisite spatial information and probe the physical and kinematic properies of the gas emitting the bulk of the [C II] and [N II] lines. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2021-01-30T20:46:28.000 |
| 730 | 2024.1.01154.S | 0 | CO(1-0) mapping toward the Antennae tidal tails | Exploring star formation in extreme environments is crucial for understanding whether star formation processes are universal or unique across the universe. Tidal tails, with their significantly different SFEs (i.e. the Kennicutt-Schmidt relation) compared to nearby disk galaxies, make ideal targets. Despite evidence suggesting widespread molecular gas, its distribution within these tails is still poorly understood. We propose to perform ACA CO(1-0) mapping of the typical tidal tails in the Antennae galaxies (22 Mpc) at a resolution of 1.2 kpc. The Antennae tidal tail is an ideal target because it is the closest tidal tail where CO has been detected and SFE is remarkably lower than that in nearby disk galaxies. This project will be the first observation to map the distribution of molecular gas in a tidal tail at kpc-scale resolution. By comparing the distribution and velocity structure of molecular gas with HI and SFR tracers, we aim to illuminate the origins of molecular gas in the tail whether through in situ formation from HI or stripping from the parent galaxies and how these processes differ from those observed in nearby disk galaxies. | Merging and interacting galaxies | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 731 | 2022.1.00946.S | 0 | Constraining the grain sizes in the young Class 0 protostar IRAS16293-2422B using polarization | The properties of the disks around Class 0 protostars, which represent the initial conditions of planet formation, have only recently begun to be probed in detail with high-resolution millimeter interferometry. Presently, many of their basic properties, including dust grain sizes remain unknown. Scattering of dust thermal emission by large grains (e.g., self-scattering) has been proposed to be the dominant effect producing linearly polarized light at wavelengths on the order of the grain size. The wavelength and grain size dependency of this mechanism turn it into a natural tool to constrain grain sizes. One interesting case study is the very young Class 0 protostar IRAS16293-2422B, which has been claimed to produce polarization by self-scattering at 1.3 mm. However, that data lacked the angular resolution to break the degeneracy between self-scattering or magnetic alignment. We aim to increase this resolution by a factor of 5 (0.05") and attempt to find whether the polarization in the disk of IRAS16293B is consistent with self-scattering or not. If self-scattering is responsible for producing the polarized light, this implies grains have grown large fast in this ~10 kyr old disk. | Low-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 732 | 2017.1.01678.S | 21 | Out of the shadows, into the light. A full examination of the disk around HD 100453 | Comparison of our ALMA observations of HD 100453 at 1.3 mm with NIR high contrast images of the same disk yields surprising insights. We detect emission at the stellar position which may come from gap-crossing accretion streams or a compact inner disk, as has been predicted from the shadows it casts on the outer disk. However, the ALMA counterpart of these shadows shows an increase in emission rather than a decrease as would be expected from a shadowed, lower temperature, disk region. The continuum emission in the outer disk shows most contrast at the location of the two spiral arms, and the 9 mm ATCA map shows a vortex-like structure under the northern spiral. Lastly, the companion at 1.05 separation is embedded in the disk as traced by CO gas, which rules out co-planar motion and puts into question whether these object are bound in orbit. This comparison evokes many questions that we propose to answer with a thorough investigation of the disk. Are the dark lanes on the outer disk really shadows? And if they are, what provokes the misalignment of the inner disk? If the stellar companion doesn't drive the spirals, what does? And is there a dust trap hidden in the outer disk? | Disks around high-mass stars | Disks and planet formation | 2019-01-22T15:34:02.000 |
| 733 | 2018.1.00649.S | 25 | Revealing the source of CI enhancement in the oxygen-rich AGB star omi Cet | To better trace the enrichment of the interstellar medium by outflows of evolved stars, it is critical to understand the chemical networks active in them. Large parts of the circumstellar envelopes (CSEs) are dominated by incident UV photons, which can efficiently photodissociate molecular gas, releasing atomic species. The best-known source of UV radiation is the interstellar radiation field (ISRF). Additionally, recent GALEX observations mark the presence of an internal source of UV emission in 180 AGB stars. This additional UV flux could drastically change the chemistry in the CSEs, but is not yet considered in chemical models. Observations of UV-photodissociation products, such as CI, can probe the effect of an internal UV source. We have recently detected CI emission towards Mira A, a UV-bright evolved star, but could not constrain its location from the single-dish observations. We propose high-angular-resolution observations with ALMA to differentiate between the roles of the ISRF, and the internal source of UV radiation, which could be the hot binary companion or a shock-heated chromosphere of Mira A itself, in the photodissociation of the circumstellar molecular gas. | Evolved stars - Chemistry | Stars and stellar evolution | 2019-12-18T14:08:56.000 |
| 734 | 2013.1.00250.S | 270 | A Redshift Survey of ALMA SMGs at z>4 from ALESS | We propose to search for the redshifted [C II]157.7um emission in a sample of 21 ALMA-identified SMGs in the Extended Chandra Deep Field South from the ALESS survey. These SMGs have photometric redshifts of z>4 and all are "red-peakers" with SPIRE 500/350>1 colours. We will use two band 7 spectral scans, f=335-365GHz and f=280-310GHz to cover the redshift range z=4.23-4.7 and z-5.16-5.82 respectively. Our primary science goals are to: i) search for the [CII] emission in order to measure spectroscopic redshifts for these SMGs and so measure their bolometric luminosities and hence the contribution of z>4 SMGs to the comoving star formation density at this epoch ii) derive the bright end of the CII luminosity function at z=4 and test how this compares to z=0 and z=2. iii) measure the ratio of CII/FIR in a well selected sample of high-z ULIRGs to test whether the "CII" deficit is ubiquitous at high-redshift. iv) search for signs of extended CII emission in the observations to place constraints on the dynamical masses which can be compared to gas and stellar mass estimates. The total time request for this program is 5.17 hours. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-11-10T07:19:10.000 |
| 735 | 2023.1.01295.S | 0 | What is the effect of luminous QSOs on molecular gas in and around galaxies? | Recent zoom-in cosmological simulations showed the importance of dust emission in launching AGN driven outflows and influencing the molecular gas supply. We propose new deep high-resolution band-6 observations and low-resolution band-4 observations of CO(7-6), CO(4-3), [CI](2-1) and [CI](1-0) and continuum emission of extremely dust-obscured quasars at z~2.3. These quasars have already been established from previous low-resolution band 6 ALMA observations as being extremely gas-rich and have massive ionised outflows of up to 6000 km/s (VLT/X-SHOOTER). With the new high resolution (2 kpc) ALMA band 6 observations we will be able to model the kinematics of the CO(7-6) and [CI](2-1) emission in order to constraint the effect of outflows on molecular gas kinematics. Furthermore, the new band-4 resolution will allow us to constrain the physical properties of the molecular gas in and around these extreme quasar host galaxies. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-06-15T00:19:13.000 |
| 736 | 2019.1.00329.S | 5 | The most extreme stellar feedback seen at GMC/A scales: ULIRGs at 45 mas | Star-formation (SF) and AGN feedback are key actors in the evolution of galaxies. Negative feedback regulates the growth of the stellar mass and massive black-holes in the bulges of galaxies. Its most evident signature is the universal presence of massive outflows in active galaxies. In this proposal, we aim to study the stellar feedback (which is thought to be dominant class of feedback for most galaxies) in a sample of 6 (5 new+1 archive) SF-dominated ULIRGs (ie the strongest local starbursts hosting massive outflows). For the first time, we will spatially resolve the relevant scale of the giant molecular cloud associations (GMC/A) and giant HII regions where feedback occurs. We propose new ~65 pc high-spatial resolution CO(2-1) observations of 5 of the brightest SF-dominated ULIRG systems. Our main goals are: (1) resolve the molecular clumps in the ULIRG disks and compare them to those found, at similar scales, in lower SF surface densities objects to identify the feedback effects; and (2) establish the outflow sub-structure and locate clumps where SF could be present (ie positive feedback). This is a resubmission of the partially observed Cycle-6 project 2018.1.00486.S. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2022-10-11T22:07:30.000 |
| 737 | 2015.1.01406.S | 17 | Anomalously faint [CII]from a merger at z=7.60 | We have recently shown A1689-zD1, a star-forming galaxy lensed by the foreground cluster Abell 1689, to be the most distant dust-emitter known using Cycle 0 and 1 ALMA imaging. We determined its redshift to be z = 7.5 from very deep near-infrared continuum spectroscopy of the Lyman break. The source is faint compared to other dust emitters so far found at high redshift, being a magnitude fainter than L at this redshift. Our Cycle 2 observation of the source with ALMA to characterise the dust mass and infrared star-formation rate and detect the [CII]158m line, has resolved the galaxy into two components and shown that the line is an order of magnitude fainter than expected for such a galaxy. We request here higher resolution and deeper observations to confirm the emission line, determine the velocities of the two components and resolve the dust emission of this UV bright dwarf galaxy to a level of detail comparable to the HST imaging. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2017-12-26T18:54:04.000 |
| 738 | 2018.1.01804.S | 91 | Are supersonic linewidths in massive star formation regions intrinsically subsonic? | Our high resolution ALMA observations of the massive Orion molecular cloud (OMC) show that most of the dense gas traced by N2H+ are subsonic. This finding indicates that more massive star forming clouds such as OMC may be intrinsically no different from the nearby Taurus cloud in its non-thermal linewidths, and that unresolved systematic motions within the telescope beam increase the linewidths. Should this be true, it would fundamentally revise the current picture of high-mass star formation. We choose a nearby, massive star formation region NGC6334, to test whether massive clouds have the subsonic linewidth as in OMC2/3. We propose to obtain high fidelity mosaic images in 3mm dust continuum and N2H+, HNC, CH3CN, HC3N lines of two massive areas in the NGC6334. One is the massive infrared dark cloud G350 located in the south of NGC6334. For comparison, we also choose a massive, active star formation clump NGC6334 I(n). The proposed study will (1) provide a high spectral and spatial resolution to resolve the non-thermal linewidth in this high-mass star formation, (2) investigate the influence of the feedback on the star-forming activities through the selected spectral lines. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-09-09T23:31:19.000 |
| 739 | 2019.1.00403.S | 38 | Unveiling obscured activities within a z=2.84 protocluster core | We propose a 6x5 continuum mapping toward a z=2.84 protocluster core down to rms=0.1mJy at 1.3mm. We recently mapped out >100 cMpc-scale structures of 3490 Lyman-alpha emitters (LAEs) around a hyperluminous QSO, HS1549+1919 at z=2.84 with Subaru/Hyper Suprime-Cam. We found that the QSO and a protocluster is located at the intersection of large scale filamentary structures of LAEs and the core region consists of 10 giant Lya blobs (LABs) and 5 AGNs. Our recent SCUBA2 observations of the core region showed that the number count of 850um sources is 6 times higher than in blank fields, suggesting accelerated galaxy formation in the protocluster core. The proposed ALMA program will test if such intense star-formation preferentially occurred in the core by comparing the number count with that in blank fields down to 0.5mJy (SFR>150Msun/yr, S/N>5). We will also investigate the connection between ALMA sources and LABs/AGNs to understand how massive galaxies co-evolve with the circumgalactic medium and supermassive black holes in the protocluster core where an enormous amount of gas could be accreting from the surrounding cosmic web. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-04-29T00:22:06.000 |
| 740 | 2018.1.01344.S | 397 | CON-quest: Finding the most obscured galaxy nuclei | Studying the accretion and growth of supermassive black holes (SMBHs) and their surrounding stellar components is essential for our understanding of galaxy evolution. Interacting Luminous and ultraluminous infrared galaxies U/LIRGs are usually strongly linked to nuclear growth since they funnel massive amounts of gas and dust to their nuclei. To study the most embedded activity, we must probe behind the curtains of dust with a line that is uniquely tracing extreme nuclear conditions. In particular, compact, luminous and extremely opaque (N(H2)>1e24 cm-2) Compact Obscured Nuclei (CONs) are extreme regions of exceptional nuclear growth. We propose a survey of the 1mm transition of vibrationally excited HCN (HCN-VIB) in a volume-limited sample of ULIRGs and LIRGs. We will investigate if CONs are uniquely formed in on-going interactions/mergers. Or if they can also be linked to more secular evolution as indicated by the surprising discovery of CONs in ISM-poor disk galaxies. The simultaneous observations of the ground state HCN and HCO+ lines will be used to chart the structure and dynamics of the central gas disk, and to search for dense outflows with extremely high sensitivity. | Outflows, jets, feedback | Active galaxies | 2019-12-17T22:11:39.000 |
| 741 | 2013.1.00700.S | 62 | The atomic to molecular phase transition in the Magellanic Stream | We propose to measure the molecular fraction of the Magellanic Stream, the closest example of a gaseous accretion stream, to constrain the formation rate of molecular hydrogen in low-metallicity environments and resolve microphysical gas properties leading to star formation. Recent studies show that the Stream contains rich atomic hydrogen structure with highly patchy and weakly-excited molecular gas, suggesting that absorption-line spectroscopy will provide the best observational constraints on its molecular abundance. We propose to search for absorption lines from HCO+, HCN, HNC and CCH in the direction of 14 radio continuum sources known to be bright at 100 GHz. We require high sensitivity (optical depth<<1), and ALMA, even in its current phase, is the only instrument that can accomplish this. The detection of dense gas tracers like HCO+ in the Stream would imply the existence of a significant cool-gas reservoir and would have huge implications for the mass and evolution of the Magellanic System, as well as provide important clues about molecular content and star formation in the first galaxies in the Universe. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2016-11-11T20:14:58.000 |
| 742 | 2021.1.00319.S | 122 | Characterization of water emission around low-mass protostellar systems | Water is strongly connected to the emergence of life and the formation of planets. Yet, we still do not know how it is delivered to planet-forming disks. Previous observations of water vapor toward protostellar systems indicate that its abundance is much lower than expected contrary to ice observations. The low abundance can be caused by early planet formation or other physical properties of the source. We propose to perform a systematic search for warm water vapor emission toward 24 low-mass protostars in various star-forming regions. By exploring a range of physical parameters such as envelope mass and luminosities, we can address the critical parameter that influences the low water vapor abundance. The optically thin H218O 203 GHz line in Band 5 and the HDO lines in Band 6 will be observed to quantify the warm water abundance and to measure the D/H ratio of the planet-forming materials. With this program, we can investigate whether or not water is delivered to planetesimal-forming zones early on, strongly indicating a fast planet formation process. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-08-19T03:05:04.000 |
| 743 | 2017.1.01704.S | 140 | A systematic survey of dense gas kinematics and filamentary flows in massive quiescent clumps | We have performed a systematic Band 6 survey of massive quiescent clumps in ALMA Cycle 3, revealing (1) sub-structure that is consistent with thermal Jeans fragmentation at the clump scale, (2) a lack of high-mass cores with core masses between 0.5-15 solar masses, and (3) pervasive hitherto undetected low-mass star formation. The clumps are massive, dense, cold, and have low virial parameter, but contain no observed high-mass protostellar objects (> 8 Msun). These observational facts are consistent with clumps that initially fragment at the thermal scale whereby high-mass stars form through "competitively accreting" gas from originally low-to-intermediate mass protostars. We propose to test this view, by observing with ALMA, for the first time, spatially and spectroscopically resolved kinematics of filamentary flows feeding low-to-intermediate mass protostars in massive quiescent clumps--from the clump scale down to the sites of protostellar accretion--and determine whether those rates are sufficient to form high-mass stars. We show how this can be done with detailed spectral line fitting of velocity coherent filaments and the comparison to cores detected in 1.3 mm continuum. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-11-14T19:31:21.000 |
| 744 | 2023.1.01415.S | 0 | Molecular gas in High-redshift HI-Selected Galaxies | The outstanding spectral capability of the ALMA correlator has inspired a novel experiment to resolve the fundamental processes driving galaxy formation at z~2. CO images of HI-selected galaxies tagged by DLAs allow one to discover and characterize the galaxies, and dissect the HI reservoirs that fuel their evolution. The current sample of 6 CO-detected HI-selected galaxies at z~2 suggests that the HI reservoirs extend from ~5-50 kpc, exhibit large metal enrichment, and have kinematics tracking the CO emission kinematics: the highest-metallicity DLAs are linked with the highest molecular gas masses. We propose to double the present CO sample, targeting 18 DLAs at z~2, 9 with high metallicity and 9 with low metallicity, and with 2-3 DLAs on each QSO sightline observed simultaneously. The CO data will yield the molecular gas mass of the HI-selected galaxies, and the impact parameters. The absorption data give the HI surface density, metallicity, and kinematics of the gas around the galaxy. With the absorption data, the ALMA CO observations will offer quantitative constraints on the properties of the `disk-halo interface', the reservoir that mediates the growth of z~2 galaxies. | Damped Lyman Alpha (DLA) systems | Cosmology | 2025-01-18T05:59:08.000 |
| 745 | 2017.1.00357.S | 70 | Is the Dust in OMC 2/3 Anomalous? | Previous studies of the OMC 2/3 star-forming filament give conflicting values for the dust emissivity index, beta. One study finds beta < 1 across the filament on 0.02-0.1 pc scales, indicative of protoplanetary-like dust on core scales. The other study finds beta ~ 1.7 across the filament on > 0.08 pc scales, indicative of micron-sized dust typical of molecular clouds. To properly convert thermal dust emission into mass in OMC 2/3, we need to measure the true value of this fundamental quantity. We propose to map the OMC 2/3 filament in Bands 4 and 5 with the ACA to characterize the SED slope where beta appears most discrepant. We will use these data to find the true shape of the SED on 0.02 pc scales, which is comparable to the first study. These results will determine whether or not the beta discrepancy is caused by (1) a flattened dust emissivity at long wavelengths, which is predicted by experimentation but has never been observed or (2) differences in spatial resolution between the two previous single-dish studies. Both results have profound implications on our understanding of dust evolution in molecular clouds. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-09-21T00:00:00.000 |
| 746 | 2013.1.00047.S | 4 | Accretion in the Mira binary system | We propose to make the first direct observations of the capture of molecular gas and the formation of an accretion disk in a binary system, using the nearby double star Mira. Mira is a well-known, mass-losing giant with strong circumstellar CO emission. It is orbited by a white dwarf companion at a separation of 0.5". The companion gravitationally captures the mass-loss of the primary and forms an accretion disk. We propose to measure the accretion stream onto the companion in the CO (3-2) line and the spectrum of the accretion disk in the continuum. These observations will provide crucial information on key aspects of stellar evolution that have never been observed before, and particularly will be used to test competing models of capture in detached binaries. ALMA makes this uniquely possible in a system where the components can be resolved. Keywords: Evolved stars - Shaping/physical structure, Asymptotic Giant Branch (AGB) stars. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2015-07-11T18:59:32.000 |
| 747 | 2016.1.00773.S | 35 | THE MM SPECTRUM OF QUIESCENT BLACK HOLE X-RAY BINARIES | The nature of the emission from the faintest stellar-mass black holes in the ALMA frequency domain is unknown. Radio and mid-IR data allow for different interpretations: (i) a flat spectrum, partially self-absorbed jet that emits all the way from GHz up to mid-IR frequencies, or (ii) a steep-spectrum, optically thin jet at GHz frequencies, plus thermal emission from a cold circumbinary disk at mid-IR frequencies. The former scenario implies that the total power output from quiescent black holes is dominated by the jet, as opposed to the accretion flow. Although this is often assumed to be the case, simply by analogy with higher luminosity systems, no observational confirmation exists. The proposed observations of the nearby quiescent black hole X-ray binary A0620-00 are designed to solve this controversy. | Black holes | Stars and stellar evolution | 2018-02-15T21:50:44.000 |
| 748 | 2016.1.01173.S | 27 | An attempt to resolve the entangled filaments and dense cores in the high-mass star formation of N159 | Our ALMA cycle1 observations toward N159, one of the most active star forming regions in the LMC, have revealed various signatures of on-going massive star formation. We have discovered young molecular outflows toward two high-luminosity YSOs, and this is the first discovery of molecular outflows in external galaxies. We have also found an indication of filamentary cloud-cloud collision which triggered high-mass star formation; a high-mass YSO with the outflow and another high-mass star with a compact HII region are formed at the intersection of two/three filaments. Here, we propose ALMA observations toward brightest 4 high-mass YSOs in N159 region at an very high angular resolution of 0.28"(0.07pc) in order to acquire deeper insights into the O star formation and their feedback on the natal gas by spatially resolving the structure. These observations will allow us to disentangle more complicated filamentary distribution including N159W-N, and to reveal significant details of the dense cores in this most active star formation in the Local Group. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2018-09-05T17:00:17.000 |
| 749 | 2021.1.00104.S | 63 | Precise dust emission measurements in high-z main sequence galaxies in the UDF | The ASPECS ALMA Large Program obtained the deepest 1.2-mm map of the foremost extragalactic deep field, the Hubble Ultradeep Field (UDF), and detected dust emission in a unique sample of main sequence star-forming galaxies at 11 main sequence galaxies. | Galaxy structure & evolution | Galaxy evolution | 2023-10-05T08:40:17.000 |
| 750 | 2016.A.00008.T | 60 | Monitoring the first ever detected accretion burst from a massive (proto)star: How accretion turns into ejection | This is a resubmission of a recent ALMA proposal for DDT, motivated by new JVLA data that not only confirm the increase of the source continuum flux at radio wavelengths, but clearly demonstrate that the free-free emission is expected to dominate the emission at 3mm and 2mm. Our goal is to study the evolution of the free-free continuum emission tracing jet ejection from the first ever detected accretion burst from a massive young stellar object (S255 NIRS3). We stress that this is not just a peculiar source, but key to understand how early-type stars form: the presence of accretion bursts is discriminant to decide whether such stars form through disk-mediated accretion like solar-type stars, or other mechanisms are required. By combining the monitoring at 3mm and 2mm with that ongoing with the JVLA from 5GHz to 44GHz, we have the unique chance to determine how the accretion burst affects the outflow process. For this purpose, we will determine fundamental quantities like expansion speed and mass loss rate. Moreover, we will compute the ratio between accretion rate (obtained from our IR observations) and mass loss rate, a crucial parameter for star formation models. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2017-07-28T07:35:06.000 |
| 751 | 2019.1.01847.S | 10 | Characterizing the properties of cold, inter-arm GMCs in M31 | We have newly identified a population of cold, compact (<54 pc) clouds in the inter-arm regions in M31, utilizing the very-deep SCUBA2 imaging. This is the first time such cold inter-arm GMCs been seen in dust emission in spiral galaxies. Their derived masses are slightly less than but comparable to on-arm GMCs in M31 and MK, but they have obviously lower dust temperatures that is closer to Plank Galactic cores, implying they are quite different GMC populations. These inter-arm GMCs may form locally, or formed on arms but fragment and migrate into off-arm regions. We propose to use ALMA to observe 850 $\mu$m continuum and CO 3-2 at band 7, and HCN/HCO+ 1-0 at band 3, towards a sample of newly identified cold inter-arm GMCs in M31, to resolve their structures, check the variation of their properties (including size, mass, velocity gradience, dense gas fraction) along different positions across a spiral arm, to distinguish GMC formation models, to test the scenario that if they can formed on arm but drift out, and to check whether they have potential to trigger massive star formation between arms. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-12-12T16:28:12.000 |
| 752 | 2023.1.01326.S | 0 | A 500 pc view of a lensed star-forming galaxy at z~2: investigating giant molecular clouds and feedback in action | The energy released by the end results of stellar evolution plays a key role in the evolution of the host galaxies, generating feedback with profound effects on the surrounding interstellar medium and even reaching beyond into the circumgalactic medium. While the connection between gas, star formation and feedback has been studied in detail in nearby starbursts, spatially resolved studies in high-z galaxies that compare feedback and metrics of star formation efficiency are currently missing. Here we propose to spatially resolve CO(4-3) and sub-mm continuum on ~500 pc scales to measure the star formation and gas in a strongly lensed, star-forming galaxy at z=2, during the peak of cosmic star formation activity in the Universe. While such measurements have been made before, the key to our program is doing so on galaxy with a spatially resolved map of outflows already measured via Keck KCWI. The direct comparison of outflow strength to the depletion time on sub-kpc scales indicates the role that outflows play in regulating star formation in galaxies, and measures the role of local star formation in driving the baryon cycle in galaxies. | Galaxy structure & evolution | Galaxy evolution | 2025-07-02T10:39:36.000 |
| 753 | 2023.1.01262.S | 0 | Resolving molecular gas in a z=2.467 DSFG with spiral and bar revealed by JWST | Dusty star-forming galaxies (DSFGs) are amongst the most massive and active star-forming galaxies in the cosmic noon. Theoretical studies have proposed various formation mechanisms of DSFGs including mergers and secular disks fed by gas accretion. We propose 0.15" resolution CO(4-3)/[CI](1-0) observation of J0107a, a bright (~8 mJy at 888 um) DSFG at z=2.467 that appears to be an extreme case of the latter scenario. With stellar mass ~1E11 Msun, molecular gas mass ~(1-4)E11 Msun and star formation rate (SFR) of ~500 Msun/yr, J0107a does not have gas-rich companion. The JWST and ALMA continuum images of J0107a show a grand-design m=2 barred spiral with dusty star formation in the ~10 kpc bar. We will resolve the gas distribution and velocity field to investigate whether there is in-situ bar formation and the effect of bar in a DSFG with very high SFR and gas fraction that has neither been considered by simulations nor observed in real galaxies. We will also search for gas inflow. The observation will help understand how the high SFR is triggered in DSFG, and may demonstrate that it can be triggered by bar and/or cold stream in a secular disk. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-01-09T00:47:55.000 |
| 754 | 2019.1.01359.S | 12 | Exploring the earliest phase of disk formation: the IRAS 15398-3359 case | The disk structure around the protostar in its early evolutional stage is an interesting target of star-formation studies. Although it is theoretically predicted that the first hydrostatic core is transformed to the Keplerian disk, we need to examine this very beginning stage of disk formation by observations. IRAS 15398-3359 is an ideal target for this purpose, which is a very low-mass protostar accompanying the Keplerian disk, as revealed by our recent ALMA observation. Discovery of this source provides us with the first observational evidence of co-evolution between the disk and the protostar. Thus, it is very important and urgent to study this source at a higher angular resolution and a higher sensitivity. In general, the first core is pressure-supported and the disk is centrifugally supported. Hence, we will study the rotation motion of the disk precisely, and carefully examine the contribution of the first core. In addition, we will inspect the stability of the disk by accurately evaluating the Toomre-Q parameter and discuss the possibility of the future accretion burst of this source. The results will present a new and important picture of the infant disk. | Low-mass star formation | ISM and star formation | 2022-08-25T19:31:20.000 |
| 755 | 2021.1.01052.S | 6 | Confirming a close quasar pair or a gravitationally lensed quasar at z=5.66 | We propose ALMA imaging of the sub-mm continuum and the [C II] line of J2037-4537, a newly discovered apparent quasar pair at z=5.66. J2037-4537 consists of two close quasar images at exactly the same redshift, which are either a physical quasar pair or lensed images of the same quasar. In the former case, J2037-4537 will be the highest redshift quasar pair, which will place strong constraints on AGN evolution models, and will enable follow-up studies including the triggering mechanism of AGN, the small-scale structures of IGM, and the search for a protocluster. In the latter case, J2037-4537 will be only the second lensed quasar known at z>5 and will be an excellent case study for the high-z SMBH population. It is difficult to distinguish the two scenarios in optical/near-IR wavelengths. We propose ALMA imaging for this system which will be the definitive test of the two scenarios. Pair and lensing hypotheses predict distinctively different continuum and [CII] morphology as well as [CII] kinematics of the two components. The proposed observation will also further probe physical properties (SFR, gas kinematics, etc.) of this unique pair/lens system. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-07-27T15:14:29.000 |
| 756 | 2022.1.00432.S | 581 | ANGELS: A New high-z submm Galaxy Efficient Line Survey in bands 3 through 8 | The Herschel Space Observatory mapped more than 1000 sqr. deg. and detected more than half a million sources. Recent redshift searches are enabling full spectroscopic follow up; however, exploiting this with ALMA is challenging, as the large overheads favour deep studies of individual sources. Here, we propose an alternative to targeted single-spectral line surveys. Based on our successful pilot observations, we aim to observe all 88 southern Herschel sources at 1.5 < z < 4.6 using ALMA as efficiently as possible to observe 370 lines. These observations will trace a multitude of lines sensitive to different phases of the ISM, including CO, [CI], and H2O, as well as fine-structure lines ([CII] and [NII]) together with the dust continuum at high resolution, revealing the nature of sources at high fidelity. We can reach this goal within 31.5 hours by observing sources in groups through quick snapshots in a single tuning set-up across Bands 3, 4, 5, 6, 7, and 8. Not only does this survey represent the largest characterization of a single sample of high-z galaxies, but this project will also provide a stacked spectrum spanning the entire rest-frame submm regime (0.1 to 1mm). | Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-05-19T21:34:45.000 |
| 757 | 2021.1.01414.S | 25 | Catch me if you can: time-variable ionization of DQ Tau disk traced via H13CO+ | T Tauri stars are active at many different wavelengths, including X-rays. The result of this activity is a variable ionization of the disk's molecular layers, but how this variability affects the disk is not yet clear. By observing a molecule like H13CO+, which is sensitive to gas-phase ion chemistry in the disk, we can gain a new window on the variable ionization in disks. Such observations require a unique model system, where the ionizing flux increases predictably. Here, we propose observations of H13CO+ spanning 8 nights of the eccentric, compact binary DQ Tau (P=15.8 days). This source is unique for its highly predictable brightening in X-ray and UV wavelengths near periastron. It has a disk representative of other (single) T Tauri stars. By combining our observations with a physical-chemical model tailored to the DQ Tau system and its activity, we will perform the first systematic study of how ionization in a protoplanetary disk, and its impact on gas-phase chemistry, change as a function of time in response to stellar activity. | Disks around low-mass stars | Disks and planet formation | 2022-12-18T01:35:37.000 |
| 758 | 2012.1.00411.S | 0 | The origin of cometary matter: nitriles and isotopes in comet C/2011 L4 (PanSTARRS) | Comets provide a record of the chemistry of the primitive solar nebula, and thereby important clues on the early evolution of the Solar Nebula. Isotopic ratios are important diagnostics because isotopic fractionation is very sensitive to chemical and physical conditions. This proposal is aimed at exploring the diversity of the DCN/HCN and HC14N/HC15N ratios in comets to understand deuterium and 15N enrichments in primitive Solar System objects. The target will be the exceptionnaly bright comet C/2011 L4 (PanSTARRS). We will also measure the C32S/C34S and C32S/C33S ratios with unprecedented sensitivity and search for CH3NC and HC2NC, never observed in comets before. Other molecules will be observed to characterize the composition of the comet, study the coma morphology and map the gas temperature distribution. | Solar system - Comets | Solar system | 2022-02-22T17:00:49.000 |
| 759 | 2015.1.00468.S | 14 | Probing stellar feedback in an extreme low-metallicity starburst | Feedback from accreting black holes and from massive stars and supernovae has become a cornerstone for understanding galaxy evolution. Recent theoretical work has shown that dust is an important aspect of stellar feedback because of the interaction of photons with dust grains. However, in the early universe, when galaxies were very metal poor, there are no observational constraints for stellar feedback, even though dust is known to play a role in primordial star formation. Here we propose to remedy this by following up on our Cycle 0 observations of an extremely low-metallicity starburst, SBS0335-052, at 1/30 solar oxygen abundance. We propose to map this galaxy in the Band 9 continuum at 0.2 arcsec resolution to compare dust morphology at a resolution of 55 pc with the distribution of the young massive Super Star Clusters. We will determine the contribution of free-free to the observed emission using high-frequency radio observations at the same resolution. Our proposed observations will provide for the first time constraints of feedback models in an extremely metal-poor interstellar medium, and better establish the metallicity dependence of dust content and column density. | Dwarf/metal-poor galaxies | Local Universe | 2019-10-02T05:46:27.000 |
| 760 | 2015.1.01487.S | 46 | Investigation of Molecular Clouds Traced by CI | We propose to observe NGC613 in CI, 13CO and C18O(1-0) with ALMA to investigate molecular cloud evolution with a spatial resolution of ~20pc. It has been considered that a dominant CI emitting region is the photo-dissociation region (PDR). However some observations of Galactic sources revealed that CI exists also deep within molecular clouds where UV radiation is attenuated. CI may also trace an early phase of molecular cloud formation from diffuse atomic clouds. The nuclear ring of NGC613 is the best targets for this study because the age gradient of stars along the ring is found from near-infrared observations. Using the age gradient and the kinematics of the molecular clouds along the ring, we can evaluate the time evolution of molecular clouds. Formation of molecular clouds from diffuse atomic clouds is supported in case that CI is enhanced in the upstream side of CO peaks or dense gas regions. The high CI-to-CO ratio in the downstream region of association of CI with massive stars means that CI is produced in PDR. Observations with high resolution toward the nuclear ring of NGC613 will clarify usefulness of CI as a molecular gas tracer and time evolution of molecular clouds. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy chemistry | Active galaxies | 2017-08-31T13:22:38.000 |
| 761 | 2024.1.01252.S | 0 | Diffuse or Dense: Probing the Physical State of Massive Gas Reservoirs in z~0.7 Quenched Galaxies | ALMA CO(2-1) observations of high-redshift (z~0.7) post-starburst galaxies indicate that the suppression of star formation does not require the complete removal of the cold molecular gas. Current quenching models cannot explain the observed large gas contents nor the state of the molecular gas in these objects. However, the CO(2-1) data alone do not offer enough insight as to why these galaxies are such inefficient star-formers. We propose to target 9 gas-rich PSBs at this epoch with deep CO(5-4) observations to understand their gas conditions. Measuring the CO excitation will allow us to distinguish between dense star-forming and more diffuse molecular gas as the line ratio is sensitive to gas temperature and density. Simultaneously, we will provide an independent check on the apparently-large gas reservoirs by detecting the submm dust continuum at high significance. The results of this program will be crucial to determine why the ample gas in these recently-quenched systems is not forming stars. | Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 762 | 2019.2.00134.S | 133 | An ACA Survey of Dense Gas in Nearby Galaxies | We propose to use the 7m+TP ACA to map high critical density 3mm lines (HCN, HCO+ and CS) across 12 nearby star-forming disk galaxies. Combined with our previous efforts, this will yield the first large (25 galaxies) sample of dense gas maps that samples local galaxy population. Our proposed targets overlap PHANGS-ALMA, and we already have detailed knowledge on the detailed gas kinematics, molecular cloud properties, star formation rate, disk structure, and dynamical environment masks for each target. We will combine the new density-sensitive spectroscopy with these in-hand data to test: (1) Do molecular cloud properties set the star formation efficiency of dense gas and the gas density distribution? (2) Is dense gas stabilized by large-scale dynamical effects in the inner parts of galaxies? And (3) is gas density driven mainly by pressure or do dynamical effects also play a large role? Given the critical need for high surface brightness sensitivity and full flux recovery, surveying density-sensitive lines in nearby galaxies represents an ideal ACA-only program. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2021-04-16T14:16:07.000 |
| 763 | 2022.1.00098.S | 20 | Microphysics and astrophysics at play in an assembling massive galaxy at cosmic dawn | Understanding how the first massive black holes and galaxies grew <1 Gyr after the Big Bang is an open question of modern astronomy. The quasar PJ308-21 at z=6.2342 is the poster child of such rapid growth. The central ~1e9 Msun black hole is accreting at its Eddington limit, embedded in a galaxy with a gaseous reservoir of ~1e11 Msun that forms ~200 new stars every year. A companion galaxy is tidally stripped by, and on the verge to merge with the host galaxy of the quasar. This exceptional laboratory of galaxy evolution has been targeted with HST, Chandra, ALMA, VLT, and will soon be studied in detail with JWST. We propose to complete this rich dataset with a sensitive search for [OIII] 88um, [NII] 122um and [NII] 205um. These three lines, together with the [CII] 158um map in hand, and the forthcoming JWST data, will unveil a suite of properties of the ionized ISM: electron density, temperature, pressure, metallicity, hardness and origin of the photoionizing flux, etc. Such a wealth of information on the microphysics of the gas is new for the distant Universe, and will open a new window on our understanding of the astrophysics of galaxy assembly and growth at cosmic dawn. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-09-15T16:33:22.000 |
| 764 | 2017.1.00604.S | 22 | Resolving the kinematic structure of a [CII] emitter 800 million years after the Big Bang | We propose deep, high angular resolution band 6 observations of [CII]158mum in a normal star-forming galaxy at z~7. This galaxy was recently spectroscopically confirmed through [CII] (at low angular resolution) and it is currently the brightest known [CII] emitter in the Epoch of Reionization. With our observations we will derive the kinematics of a galaxy in a very early stage of galaxy formation and we will test if this distant system is forming its stars in a well-ordered, gas rich disk or if the source is dominated by turbulent gas motion. We will furthermore investigate the morphology of the gas and dust and determine the offsets and spatial extend of these ISM components with respect to the stars that are visible in the rest-frame UV. | Galaxy structure & evolution | Galaxy evolution | 2019-10-10T17:53:14.000 |
| 765 | 2015.1.00137.S | 382 | Evolution of ISM, Star Formation and Starbursts | We propose to extend our extremely successful program of measuring interstellar (ISM) masses in high-z galaxies at the peak of cosmic star formation and active galactic nuclei (AGN). Our technique uses optically thin dust emission as a proxy for the ISM gas mass -- calibrated using Planck observations of the Milky Way, nearby galaxies and SMGs at z ~ 2. The sensitivity and resolution of ALMA make the technique very quick and reliable (avoiding issues of CO conversion factors). In Cycle 2, we found very large increases in the ISM masses as one goes above the main sequence and at higher z. Confirmation of this important result requires observations of a larger and IR-complete sample. We propose 368 galaxies in the redshift ranges z = 1-2, 2-3 and 3-5 (43% with spectroscopic redshifts). All have good detections with Herschel, providing a reliable accounting of the dust-obscured star formation and AGN. These extensive samples will be used to map the evolution of ISM mass as a function of redshift, galactic stellar mass, and star formation rate relative to the main sequence. 59 of the galaxies have X-ray AGN to be compared with non-AGN samples. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2017-04-04T19:14:38.000 |
| 766 | 2019.1.00673.S | 22 | The highest resolution imaging of the Sunyaev-Zel'dovich effect at z~1 | We propose Band 3 observations of the Sunyaev-Zel'dovich effect (SZE) toward a distant galaxy cluster RCS J2319.8+0038. As the most massive object in a supercluster at z=0.90, RCS J2319.8+0038 has been detected at high significance in both an SZE survey by the Atacama Cosmology Telescope (ACT) and an optical survey by Hyper Suprime-Cam (HSC). The ACT data suggest a significant positional offset of the SZE signal from the X-ray peak measured by Chandra, whereas the HSC data point to complex distribution of member galaxies. We aim at i) revealing the dynamical status of RCS J2319.8+0038 by measuring the offset accurately and detecting (if present) shocks, ii) mapping the projected gas pressure and reconstructing the inner pressure profile, and iii) measuring the temperature profile in conjunction with the existing X-ray data. This will be among the first such measurements at z~1 and can only be accomplished by deep ALMA observations. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2021-03-12T17:32:51.000 |
| 767 | 2019.1.00807.S | 180 | ACA Monitoring of Event Horizon Telescope (EHT) targets during the April 2020 EHT Campaign | The Event Horizon Telescope (EHT) Collaboration (EHTC) is requesting observations of several sources in Cycle 7, with the aim of resolving black hole shadows and jet launching regions in AGN. These are expected to be observed over a 2-week window in April 2020, using several ~5-15 hr observing runs, triggered based on weather and telescope readiness, i.e. individual sources will be observed over several days with unpredictable gaps in daily coverage. Here we propose daily ACA monitoring of four key EHTC-proposed sources: SgrA*, M87, 3C279, and OJ287 - during the EHT campaign. The primary goals of this proposal are to obtain: (a) better than 10% absolute flux calibration (per daily epoch) for all sources in the EHT observing runs (via bootstrapping); (b) constrain the origin of variability (e.g., proper motions vs relative brightening of individual components, or hot-spot orbits in Sgr A*) seen in EHT images on individual days; (c) a better comparison with the multi-wavelength (cm to X-ray) campaign. Overall, these observations will lead to a significantly better, and perhaps crucial, understanding of the physical mechanisms leading to variability on event horizon scales. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2022-05-07T17:40:26.000 |
| 768 | 2022.1.00012.S | 36 | ALMA-JWST Joint Efforts on Calibrating Gas-Phase Metallicities of Star-Forming Galaxies in the Reionization Era | The gas-phase metallicities of high redshift galaxies are valuable probes of early galaxy assembly and chemical enrichment. However, traditional strong line methods rely on calibrations which have been shown to evolve with redshift due to the changing ionization properties of the interstellar medium. While some progress has been made on redshift-dependent calibrations at z~2 using temperature-sensitive auroral lines (e.g. [O III]4363), this approach is impractical beyond z~6. We propose to obtain direct-method metallicities for 3 galaxies at z_spec=6.0-7.2 by observing the [OIII]52um emission line. Our targets are already detected in [OIII]88um and have approved JWST observations targeting the key rest-optical lines, including [OIII]5007. The addition of [OIII]52um will provide electron temperatures, densities, and ~0.1 dex precision metallicities for the first time at such redshifts. ALMA measurements of [OIII]52um are the only feasible route for enabling a robust metallicity and chemical evolution analysis of these targets, which will serve as the crucial calibrating anchor for more extensive JWST and ALMA studies in the reionization era. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2024-04-26T16:32:18.000 |
| 769 | 2015.1.00819.S | 20 | The evolution of small solids in protoplanetary disks: a 3mm ALMA survey in Upper Sco | We propose to observe 24 disks in the Upper Sco star forming region at about 3 mm with ALMA in Cycle 3. By combining these observations with the detections obtained for these disks at 0.89 mm, we will measure for the first time the mm-spectral index of disks towards the end of their lifetime, i.e. ~ 5 - 10 Myr. These observations will tell us whether trapping of mm/cm-sized particles, observed in the outer regions of younger disks, occurs also at the end of the disk lifetime, or whether radial drift of these solids takes over a few Myr after the disk birth. This is crucial for our understanding of the formation of planetesimals, and therefore of planets, since it is in these dust traps that planetesimals are expected to form. | Disks around low-mass stars | Disks and planet formation | 2017-04-14T16:55:30.000 |
| 770 | 2017.1.01248.S | 437 | Formation process to glycine's precursors, CH2NH and CH3NH2 | We propose to conduct observations of CH3NH2, CH2NH, and CH3OH to investigate the formation process to glycine. While CH2NH and CH3NH2 are suggested as possible glycine precursors, their formation processes are also not well established. According to our chemical modeling, CH3NH2 was formed via successive hydrogenation to HCN on grains, while CH2NH was formed in the gas phase reactions. It would be essential to investigate if these suggested formation processes agree with actual observations. CH3OH, whose formation process is well known as hydrogenation process to CO would be a key molecule. Since both of CH3OH and CH3NH2 showed their peak abundances just after the birth of a star, "CH3OH/CH3NH2" would show small time dependence. On the other hand, our modeling results predicted that "CH2NH/CH3NH2" would strongly change along with the evolution of star by almost a factor of 1000. Therefore, we propose to give the evidence for predicted formation processes by obtaining accurate "CH2NH/CH3NH" and "CH3OH/CH3NH2". We have selected best four sources from our past survey of CH2NH. We will be able to reach our science goals with 7.2 hour of total ALMA time | Astrochemistry | ISM and star formation | 2019-05-28T06:32:39.000 |
| 771 | 2018.1.01639.S | 158 | Highly deuterated starless cores with low CO freeze out: a chemical puzzle | Deuterated molecules, in particular N2D+, are excellent tracers of cold, dense gas, and thus they are ideal tools to study the initial conditions in the process of star formation. The deuterium fraction is known to decrease outside of the CO depletion zone in dense cores. Recent observations have revealed the presence of dense cores with high deuterium fractions and low CO-depletion factors which contradicts chemical models of dense cores. One way to reconcile theory with observations is to have small or clumpy cores. We propose to observe the N2D+(3-2), N2H+(3-2) and C18O(2-1) transitions and dust continuum emission towards eight highly deuterated starless cores which show low CO freeze out, in L1688, in Ophiuchus. We will measure the deuterium fraction, the CO depletion factor and dense gas distribution, traced by the N2D+ and N2H+ (3-2) transitions, on 5" scales. We expect the dense gas to be concentrated in small (~5-10") CO depletion zones not detected with prior single dish measurements. Alternatively, extended N2D+ emission in CO rich gas would testify to peculiar environmental conditions in these cores, such as low cosmic ray ionization rates or atypical dust grain sizes. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-01-20T17:55:32.000 |
| 772 | 2015.1.00612.S | 6 | Observations of the [Cii]Emission Line in Hot, Dust-Obscured Galaxies | The WISE mission has recently identified a rare population of high-redshift, hyper-luminous infrared galaxies, all with bolometric luminosities above 10^13 L_Sun, and many exceeding 10^14 L_Sun. Characterized by their extremely red mid-IR colors and very hot dust temperatures, these hot, dust obscured galaxies (Hot DOGs) likely probe a key stage in the galaxy evolution paradigm. The bulk of the IR emission in Hot DOGs is powered by AGN activity, outshining possible fainter cold emission associated to star formation. The only way to study the ISM properties of the host galaxy in these objects, as well as the effects of the AGN on it, are through kpc-scale imaging of the dust and gas at sub-mm wavelengths. We propose here to use ALMA to obtain deep, high-resolution observations of the 157.7um [CII] emission line and of the FIR continuum in a small sample of carefully selected Hot DOGs to constrain the physical properties of the their dust and gas components and gain insights into their star-formation properties. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2017-11-08T18:29:54.000 |
| 773 | 2022.1.00764.S | 0 | Formation Of Sub-Structure In Luminous Sub-millimeter galaxies (FOSSILS) | The brightest dusty star-forming galaxies are the most probable ancestors of the massive galaxies that dominate the central potential of clusters we see today. Mergers or large-scale gas inflow in isolated disks are possible scenarios explaining the observed large star formation rate, but the exact triggering mechanism is unclear, mainly due to insufficient high-resolution samples to draw a general conclusion. Here we propose to observe 30 unlensed submillimeter bright galaxies at 0.06" resolution in Band 7 to address this problem. For the first time, a total of 40 statistically significant samples of 300-400 pc resolution images will allow us to analyze the spatial distribution of the extended dust and star formation statistically. We will parameterize the galaxy structure and search for major/minor companions in the ALMA and multi-wavelength data, complemented by a detailed comparison with hydrodynamical simulations. With only a modest ALMA time investment, increasing the sample by 4x, this project will provide a significant impact on the field by offering a robust physical process for the assembly of massive galaxies in the early universe. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2024-11-24T19:05:21.000 |
| 774 | 2018.1.00680.S | 37 | The highest resolution imaging of the Sunyaev-Zel'dovich effect at z>1 | We propose Band 3 observations of the Sunyaev-Zel'dovich effect (SZE) toward a newly discovered galaxy cluster, HSC J0947-0119 at z=1.18. This system is the richest and the most massive galaxy cluster detected so far at z>1 by both Hyper Suprime-Cam (HSC) and the Atacama Cosmology Telescope (ACT). Signatures of an on-going merger are indicated by the HSC data, whereas strong SZE signal is warranted by the high significance ACT data. With the proposed 4 arcsec angular resolution, we aim at revealing an early evolutionary stage of HSC J0947-0119 by mapping the projected gas pressure, reconstructing directly the inner pressure profile, and detecting (if present) shock-heated gas. This will be the first such measurement at z>1 and can only be accomplished by deep ALMA observations. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE) | Cosmology | 2020-02-21T00:43:47.000 |
| 775 | 2016.1.01114.V | 0 | Imaging the candidate binary SMBH in OJ287 | We propose 1 mm EHT+ALMA observations of the BL Lac object OJ287, one of the best candidates for hosting a binary SMBH and to study jet formation in magnetically dominated AGN. The improvement in the north-south resolution and sensitivity provided by ALMA and the comparison with quasi-simultaneous, resolution-matched 3 mm GMVA+ALMA and 1.3 cm space VLBI RadioAstron images will allow us to perform Faraday rotation synthesis and opacity analysis approaching linear scales of 26 Rs. This would allow determination of the spectral energy distribution in the jet and the three dimensional structure of the magnetic field to test the binary SMBH scenario and to test magnetically driven jet formation models. In particular we plan to i) search for a secondary VLBI core/jet to confirm the binary SMBH model; ii) determine the spectral properties of the central region; iii) determine the orientation and strength of the magnetic field, and the location of jet transition from Poynting-flux to kinetic energy-dominance; iv) resolve the Faraday screen of the accretion flow around the SMBH and the inner jet, and derive the mass accretion rate; v) discriminate between BBH model and rotation jet-model. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-10-20T14:57:15.000 |
| 776 | 2015.1.01454.S | 262 | The Structure of Massive Protostellar Cores | We propose to characterize the 1.3 mm dust continuum structure of 8 massive protostellar cores over a wide range of scales from ~0.14" to ~12", i.e., ~300AU to 24,000AU at typical distance of 2kpc. The results will be compared against sophisticated radiative transfer models of Core Accretion, which are already constrained by our SOFIA-FORCAST MIR to FIR observations of these same sources. In particular, we will examine to what extent simple, symmetric core models can remain valid when confronted with these new ALMA observations. Our spectral set-up also includes a suite of lines to potentially probe dense gas in core or disk and outflows. In a companion proposal, we seek to observe these same sources with same spectral set-up at resolutions of up to 0.035", and these data would be combined with the observations proposed here to yield images that probe a very large range of scales in massive protostellar cores. Even the results of this project on its own will provide stringent new tests of massive star formation theories. However, in combination with the long baseline companion observations, it will enable truly revolutionary vistas of massive star formation. | High-mass star formation | ISM and star formation | 2017-07-14T20:34:32.000 |
| 777 | 2019.1.01074.S | 70 | The quest for substructures in the early stages of protoplanetary disks | Disks in the early stages (Class 0 and I) of low-mass star formation are the precursors of well-studied more evolved protoplanetary disks (Class II). The latter show clear evidence of substructures, which could be induced by planet formation, as well as evidence of grain growth. A fundamental question is how early these processes begin and therefore, when and on what timescales planetesimal formation starts. We propose to image five bright sources in the dust continuum at band 3 and 6 at spatial resolutions of 8 au and 6 au, respectively. These sources cover evolutionary stages from the Class 0 to I phase, and have been observed at short/intermediate baselines by the FAUST large program. Our observations will determine: (1) prevalence and properties of early substructures; (2) spatial variations of the dust continuum spectral index, which is related to the optical depth and dust grain size distribution; (3) the radial profile of the disk emission which, by comparison with models, will help constrain the dust temperature for both disk and envelope, further improving FAUST determinations of the chemical composition that will be inherited by more evolved protoplanetary disks. | Low-mass star formation | ISM and star formation | 2022-09-09T21:14:32.000 |
| 778 | 2024.1.00681.S | 0 | Dynamically determining the origin of gas in debris discs | ALMA observations over the last 10 years have imaged debris discs at unprecedented sensitivity and revealed that many young discs contain vast amounts of CO gas, whose origin is still debated. ALMA and JWST observations of the archetypal gas-rich disc, HD21997, showed an extreme spatial segregation of dust of different sizes. While the large dust distribution seen by ALMA is concentrated between 60 and 120 au, the small grains seen by JWST peak at 150 au. This extreme segregation could be explained by gas drag acting on the small grains making them migrate outwards. We propose high-resolution dust and gas observations of HD21997 to understand the gas-dust interactions. By resolving the distribution of large grains we will quantify the observed outward migration of small grains. The CO observations will constrain the distribution and kinematics of gas to ultimately produce a detailed dust migration model to compare against our multiwavelength dust observations. Our program will constrain dynamically the amount and origin of gas present in this gas-rich debris disc through dust migration models, to truly understand the influence of gas on these newly born planetary systems. | Debris disks | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 779 | 2013.1.00049.S | 2 | An Unprecedented ALMA View of the Massive Molecular Outflow in NGC 6240 | The massive molecular outflows recently discovered in several nearby active and/or starburst galaxies can significantly affect the evolution of the galaxy, by quenching the star formation in short time-scales. We propose sensitive [CI]3P1-3P0, 13CO(1-0) and CS(2-1) imaging and spectroscopy of the local AGN-host LIRG NGC 6240. Our goal is to detect at high significance and spatially resolve the faint and broad (FWZI of 1400 km/s) component of these emission lines (superimposed onto the narrower and brighter core coming from the star forming gas disk), which traces a massive and extended molecular outflow . With this proposal we aim to exploit the new ALMA Cycle 2 capabilities to make a significant step forward in our investigation, by studying in unprecedented detail the physics of the NGC 6240 molecular outflow, to examine whether the outflow is strong enough to entrain also high-density gas (the primary SF fuel), and at the same time to exploit the new Band 8 to test an innovative method for exploring molecular outflows using the [CI](1-0) transition, which will be of great legacy value for future, high redshift (z>2) studies with ALMA. | Outflows, jets, feedback | Active galaxies | 2016-08-07T00:00:00.000 |
| 780 | 2023.1.00714.S | 0 | Gas dynamics reveals the mechanisms that trigger the most luminous starbursts in high-redshift protoclusters | The discovery of exceptionally starbursting cores (total SFR>=3000-5000 Msun/yr) of galaxy protoclusters in a phase of rapid assembly at z~2-4 has recently defied our understanding of how massive galaxies form in extreme overdensities. Strong starbursts in protoclusters might be triggered via the steady accretion of cold gas streams (predicted by simulations) or by classical mergers and interactions. Spatially unresolved observations have so far provided conflicting results. Here we propose to discriminate between these two scenarios in a quintessential starbursting protocluster (SFR~7000 Msun/yr over ~100 kpc) at z=2.41 by highly resolving the molecular gas emission in 2 HyLIRG+3 ULIRG members in one pointing. Armed with 0.12" resolution maps of [CI](1-0)+CO(4-3), we will accurately determine their dynamical state via 3D modeling and explore sub-galactic ISM conditions from the line ratio map. The existence of dynamically cold disks (V/sigma~10) would support efficient accretion of co-planar and co-rotating streams even in massive halos; alternatively, non-circular motions in the position-velocity diagrams would strongly support to the merger scenario. | Galaxy groups and clusters, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Cosmology | 2025-01-11T20:50:57.000 |
| 781 | 2017.1.01392.S | 3 | Testing magnetic braking in the young B335 protostar | The absence of detected rotational motions in the B335 protostar, as well as our first ALMA detection of polarization at scales ~500 AU in the envelope, suggest an efficient magnetic braking at work in this very young protostar. Our ALMA Cycle 2 data, delivered in November 2016, shows an intriguing polarized emission map, which could either suggest (i) at least two different grain alignment mechanisms at work in B335 to produce the observed polarization pattern, or (ii) insufficient spatial coverage of our Cycle 2 data, suffering from larger filtering effect than expected. In order to interpret the polarization emission obtained in B335, and utimately use it to characterize the topology of magnetic fields in this young protostar, we propose to obtain continuum polarization maps of B335 with ALMA in Band 6 (to complement our Cycle 2 data) and Band 3 (to reach the larger envelope scales up to 10" from the central protostar). The resulting ALMA polarization map will have enough spatial coverage to probe all scales where magnetic braking might be playing a role to slow down the rotation and prevent the formation of a large disk in B335. | Low-mass star formation | ISM and star formation | 2019-06-28T09:59:03.000 |
| 782 | 2021.1.01082.S | 20 | High-redshift CIV hosts: revealing a new class of early galaxies with ALMA | While it is commonly believed that early star-forming galaxies were the core driver of cosmic reionisation, only bright examples at z>5.5 can be spectroscopically observed to measure their ionising capability. This is a major hurdle given that UV-faint systems are likely the dominant source of ionising photons. Metal absorbers found in the spectra of background QSOs offer a new approach. A major step has been the detection of [CII] emission in similar absorbers at z~4 which are undetected in deep UV images due to dust obscuration. We propose to extend this method to z~6 to analyse the similarly UV-faint host galaxies of strong CIV absorbers. The presence of large amounts of triply-ionised carbon at z>5.7 requires physical mechanisms distinct from later times. If the CIV hosts are faint in [CII], we will derive a direct constraint on their above-average ionising power, a key unknown in reionisation. If they are bright, they would correspond to high-z sub-mm galaxies: highly star-forming, but UV-obscured. In either case, a deep search for [CII] emission with ALMA will reveal a new class of galaxies unique to the z>5 Universe, with far-reaching consequences for early galaxy evolution. | Damped Lyman Alpha (DLA) systems, Galaxy structure & evolution | Cosmology | 2023-12-20T18:20:11.000 |
| 783 | 2022.1.00131.S | 1630 | Outflows in Class 0/I Protostars with ALMA: A multi-scale approach | This proposal aims for a comprehensive, homogenous study of 19 nearby (<200 pc) protostars driving known outflows, leveraging the carefully curated Class 0/I sample from the eDisk Large Program. Optimizing ALMA's mapping capabilities and spectral setup, we propose to observe in Bands 3 and 6, targeting 18 molecules that probe (1) outflow morphologies and kinematics; (2) photochemistry; and (3) complex organic chemistry. The scientific goals include studying outflow rotation, orientation on large- to small-scales, and the outflow-disk relation. We will complement ACA maps with higher-resolution single pointing observations to link the larger scale structures to the outflow characteristics near the launching point of well-characterized disks. These extensive observations contribute to an unprecedented catalog of outflow maps for a representative sample of nearby protostars. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2024-02-13T17:05:26.000 |
| 784 | 2018.1.00915.S | 6 | Dark Matter Substructure and Intermediate-Mass Black Holes in Gravitational Lens B1422+231 | Quadruply-lensed high-redshift quasars may show lensed-image flux ratio anomalies that deviate from the expected cusp relation. Causes include lens model substructure, propagation effects, and subsidiary effects. B1422+231 exhibits flux ratio anomalies from radio to X-ray bands but lacks key data in the millimeter (mm) band. We propose here to observe B1422+231 at high angular resolution and high sensitivity using ALMA. This will measure accurately any flux density ratio anomaly. The image data will also allow a search for dark matter substructure down to less than a million solar masses in the foreground galaxy halo using existing MCMC methods. Additionally, if a dark matter substructure is unable to explain the observations fully, the probability of a population of intermediate-mass black holes ranging from ten to less than a million solar masses will be explored. These observations will therefore provide valuable constraints on the cusp relation and lensed image structure of this important source at mm-wavelengths and allow an important exploration of the mass function of compact perturbers to the smooth lensing model of this system. | Gravitational lenses | Cosmology | 2021-01-22T03:54:33.000 |
| 785 | 2021.1.01320.S | 90 | Opening an Era of CGM-scale Study of the Most Massive Halos at z>6 with ALMA | We systematically analyzed the [CII]158um data for N~40 quasars at z>6 including the ALMA public archive and found five quasars likely with remarkably extended [CII] morphology up to r~10-30 kpc based on both visibility and image-based analyses. The 30-kpc scale generally exceeds the maximum recoverable scale of previous ALMA observations, which might have beem missed in previous ALMA observations. Here we propose deep [CII] follow-up for these five quasars with compact+extended configurations. In conjunction with the data taken in previous cycles, the combined data will achieve moderate resolution (~0."4-0."5 or ~3kpc) as well as recover the total flux potentially extended up to the ~30-kpc CGM scale, which is tested by mock observations with CASA simobs. We will 1) test the existence of the ~30-kpc scale structure, 2) study the detailed morphology of the CGM-scale [CII] gas, and 3) constrain the dark matter assembly of luminous quasars at z>6 by examining the potential fall-off in the rotation curve up to ~7-8 x effective radius of the host galaxy. Our proposed observations will open an unprecedented CGM-scale view of the most massive halos at z>6 with ALMA for the first time. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-06-09T11:17:04.000 |
| 786 | 2016.1.00191.S | 1922 | Characterizing the hot molecular core phase | Despite recent advances in the characterization of the early stages of intermediate/high-mass star-forming regions, many questions remain still open. In particular, questions regarding the earliest phase known to date in the formation of a massive star: the hot molecular core (HMC) - characterized by high temperatures (>100 K) and a rich chemistry. Must all the (high-mass) protostars undergo the HMC stage? Are the HMCs specifically associated with dominant star formation phenomena (infall, outflow, ionized gas)? Which is the lifetime of HMCs (there are notable discrepancies between the number of known HMCs and the number predicted by theoretical and chemical models)? Current surveys of dense gas tracers toward large samples of massive young stellar objects have not followed a statistically reliable strategy to search for HMCs. We propose to carry out sensitive observations of high-energy spectral lines, to probe the presence of HMCs towards a large sample of star forming regions. By observing reliable hot core tracers we aim: (1) to detect and classify HMCs, and estimate their lifetimes; (2) to determine the relation of HMCs with infall, outflow and ionized gas. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2018-04-08T16:39:21.000 |
| 787 | 2015.1.01104.S | 40 | Exploring the pulsar spectra in the sub-mm with ALMA | Studying pulsar spectra is key to understand the physics of the emission processes in their magnetospheres and the behaviour of relativistic particles and radiation under extreme magnetic field conditions.The harvest of pulsar detections in gamma-rays by Fermi (~160) has triggered follow-up multi-wavelength observations,mainly in the X rays and in the optical,and made extensive studies of the pulsar spectra possible for the first time.To set the complete picture,however, expanding the observations to other wavelengths is crucial.Indeed, only a handful of pulsars are detected all the way from the gamma-rays to the radio, owing to the lack of sensitive observations at low-energies.In particular,no pulsar has been observed so far in the sub-mm, a crucial wavelength range to investigate the transition between coherent and incoherent radiation emission processes, occurring between high radio frequencies and the infrared.We propose to use ALMA to search for sub-mm emission from the Vela pulsar,a well-known gamma,X-ray,and optical pulsar.Being one of the very few detected in both the near and mid-IR,Vela is an obvious candidate to be the first pulsar ever detected in the sub-mm with ALMA. | Pulsars and neutron stars | Stars and stellar evolution | 2017-07-07T15:39:57.000 |
| 788 | 2023.1.00887.S | 0 | The mm Fundamental Plane of Black Hole Accretion of Stellar Mass Black Holes: Persistent Transients | A "mm fundamental plane of black hole (BH) accretion" has recently been discovered, analogous to the radio one. Its scatter is however much smaller (0.4 dex), nearly as small as that of the BH mass - stellar velocity dispersion relation. Surprisingly, it is also obeyed by all galaxies with an active galactic nucleus (AGN), with both high and low accretion rates, and is well explained by advection-dominated accretion flow (ADAF) models but not by classic geometrically-thin accretion disc models. This new mm fundamental plane thus provides both the most accurate proxy (i.e. indirect estimate) of BH mass and crucial new insights into BH accretion physics. However, it is as yet unknown whether stellar-mass BHs in accreting systems also follow this plane. This proposal therefore aims to i) ascertain whether stellar-mass BHs also follow the mm fundamental plane of BH accretion, by observing all known (and accessible) quasi-persistent transients (4 X-ray binaries), and ii) establish whether ADAF models also explain the mm fundamental plane of BH accretion of stellar-mass BHs, as they appear to do for AGN of all accretion rates. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-12-27T20:32:09.000 |
| 789 | 2012.1.00368.S | 2 | Revealing the Density and Kinematic Structure in the Serpens Active Star Formation Region | We propose to unveil the morphology, kinematics, and density structure of the dense molecular gas in a 0.19 x 0.15 pc (1.5' x 1.2') region of active star formation in the Serpens Molecular Cloud with 800 AU (1.7") resolution. This dense gas is intimately associated with current and future star formation in this cloud. Its distribution directly impacts current theories for clustered star formation and the role of turbulence, and provides insight into how star formation carves the parent core. The proposed ALMA observations of the CS 7-6 and 5-4 lines and H2CO 5,1,5-4,1,4 and 3,1,2-2,1,1 lines probe the physical density and distribution of the high density (n > 10^5 cm^3) molecular gas. Observations of C34S 5-4 provide a check on the CS 5-4 opacity, and the HCN 4-3 line will be used in combination with CARMA HCN 1-0 data as an additional high density probe. A wide spectral window in Band 6 and Band 7 will provide 1300 and 900 micron continuum maps, respectively. Combining ALMA molecular and continuum maps with Herschel images of dust distribution and heating, and Spitzer data on young stellar populations, we will assemble a detailed picture of the young stars and the structure of dense gas that will challenge current theories of star formation. The 12-m and ACA imaging are required to obtain images with full recovery of flux. The images will be used for clump finding analysis, velocity and spatial distribution analysis, comparison to turbulent star formation models, and physical density mapping. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-01-15T22:03:43.000 |
| 790 | 2021.1.00099.S | 189 | ALMA Carbon Monoxide Supernova (ACOS) survey: testing the single-star and binary models of type Ic supernovae | The conditions necessary to form progenitors of given types of supernovae (SNe) are poorly understood. We propose to test the single-star and binary models of the most extreme SNe of type Ic using the fact that these models predict different progenitor masses, which in turn imply different progenitor lifetimes and therefore different states of the parent molecular clouds at the time of explosion. If the single-star model is correct, then most of type Ic SNe should be associated with their parent molecular clouds, and the distribution of molecular hydrogen surface density at their positions should be shifted towards higher values compared with those at the positions of type II SNe. On the other hand, if the binary model for type Ic SNe is correct, then their progenitor masses (and lifetimes) are similar to those of type II SNe, and the distributions of molecular hydrogen column surface density of their sightlines should be similar. The knowledge of the model (single-star vs. binary) of type Ic SNe is necessary to study their role in metal enrichment and feedback on star formation. | Supernovae (SN) ejecta | Stars and stellar evolution | 2023-05-10T15:06:08.000 |
| 791 | 2013.1.00973.S | 3 | Spatially resolved H3O+ maser emission in starburst galaxies | We have clearly detected emissions from H3O+ in the nuclei of satrburst NGC253, NGC4945 and ULIRG ARP 220. We observed two transitions for H3O+ for all the galaxies survey using APEX telescope. Transition at 364 GHz is observed with an intensity way above that predicted by LTE or non-LTE excitation based on the intensity measured in the 307 GHz line. The H3O+ molecule can be used as a tracer of the ionization rate of dense circumnuclear gas in galaxies. Either in the molecular disk surrounding the nuclear black hole or in galactic jets molecular excitation can result in megamasers emission with large luminosities. We aim to probe the origin of this new potentially megamaser line. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2016-12-31T00:00:00.000 |
| 792 | 2017.A.00053.S | 56 | ALMA ACA Band-8 observatory project: Mapping fine structure lines of neutral atomic carbon in local bright galaxies | The fine structure lines of neutral atomic carbon have been proposed to be robust tracers of the molecular gas, offering a new way for us to probe the molecular gas mass in extragalactic environments, especially for high-redshift galaxies, whose CO(1-0) lines are very difficult to access. Here we propose an ALMA Band-8 ACA observatory project mapping the 492GHz [CI](1-0) transition in a group of infrared bright nearby galaxies, who are located within the 22:00h-01:30h LST range. The goal is to study the spatial distribution of the atomic carbon gas, compared with the existing images of other gas tracers such as CO(1-0), to test the proposed scenario. The kinematical information from the proposed data will also allow us to understand the dynamical properties, and possibly revealing detailed structures. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2019-03-05T00:00:00.000 |
| 793 | 2018.A.00023.S | 5 | Confirming Phosphine in the Atmosphere of Venus | We have detected phosphine (PH3) gas in the atmosphere of Venus, through a JCMT observation of the 1-0 absorption line at 267 GHz. This is highly significant as PH3 only occurs in nature as a biosignature gas on Earth. The abundance of a few parts-per-billion is consistent with the hypothesis of an aerial biosphere in the cloud decks of Venus, of microbes that evolved upwards to escape the runaway greenhouse effect. We show that non-biological production routes are predicted to have very low yields for Venus, and so PH3 is a very distinctive biomarker. We are proposing (**in confidence**) to independently confirm the JCMT detection, and to map out the distribution of PH3 to test against biological and alternative models. The project can not wait for Cycle 7, as in the pre-announced configuration schedule, a suitable short-baseline configuration does not occur when Venus is suitably illuminated. We thus propose for DDT (category 2/3) in the first half of March 2019, using C43-1. The outcome will be either a compelling candidate biomarker that can be followed up by in-situ sampling missions to Venus, or a remarkable discovery of very unusual planetary geochemistry/photochemistry. | Solar system - Planetary atmospheres | Solar system | 2020-11-15T00:00:00.000 |
| 794 | 2013.1.00247.S | 12 | AGN Feedback in Action: The Molecular Outflow in the Nearest Active Galactic Nucleus | Galactic winds/outflows are poorly understood although they are essential to feedback processes that quench star formation and limit the total mass of large galaxies in today's universe. Thus, insufficient understanding of feedback associated with them, in particular of the molecular phase, is one of the greatest shortcomings in our knowledge of galaxy evolution. Outflows associated with galactic winds are fueled by both starbursts and AGN, and the ways in which the two winds differ is unknown and can only be gleaned through observations of both. Modeled after previous successful ALMA observations of a starburst driven wind, with 1.2 hours of ALMA time on source we will observe the AGN driven wind within the central 1.5' of Circinus, the nearest Seyfert galaxy. We will assess the morphology and kinematics of the molecular wind, and estimate the molecular outflow rate. | Outflows, jets, feedback | Active galaxies | 2016-04-28T00:00:00.000 |
| 795 | 2016.1.01265.S | 9 | Are star-forming clumps coupled to the ISM in dense galaxies? | It has been proposed that star-forming clumps in high-redshift normal galaxies are created from Toomre fragmentation in dense rotating disks. At great distances, however, this is difficult to measure, due to low signal-to-noise ratios and poor physical resolution. Here, we propose to take advantage of a local sample of dense star-forming galaxies which appear to follow local scaling relations between gas and star formation (as opposed to infrared-bright objects) in order to understand the formation of gas clumps with surface densities that exceed 1000 Msun/kpc2. Is Toomre fragmentation enough to explain the observed properties, or is star formation efficiency strongly enhanced in these regions? We will compare gas masses and surface densities in different clumps and the underlying ISM in order to infer whether clumps with higher efficiencies are effectively decoupled from their surroundings. | Starbursts, star formation | Active galaxies | 2019-03-01T18:58:04.000 |
| 796 | 2015.1.01535.S | 35 | Revealing a new population of UC-HII regions with maser RRLs | The physical processes leading to formation of high mass stars is one of the most discussed issues in Astrophysics. This poorly known field has experienced some progress thanks to the detection of some circumstellar disks around massive stars supporting formation via monolithic collapse. The circumstellar disk with best known kinematics is that found toward the UC-HII region of MWC349A. The centroid map obtained of its RRL emission has turned out to be the best tool to study the geometry, physical characteristics and kinematics of its ionized disk and wind at small spatial scales. We intend to carry out a pilot survey of high-angular resolution by using ALMA to study the kinematics of ionized disks and winds in UC-HII regions with, potentially, RRL maser emission. However, their expected LTE intensities are enough strong to detect the Hnalpha RRLs with high signal-to-noise ratios by using ALMA and, therefore, to obtain their centroid maps with uncertainties of about a few milliarcseconds. The ALMA data would provide insight into the physical mechanisms of launching and shaping ionized winds with the ultimate goal of understanding monolithic massive star formation. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2018-06-15T00:29:28.000 |
| 797 | 2016.1.01172.S | 73 | Local Insights into the Most Extreme Star Formation at High Redshift | We have identified five exceptional z~0.08-0.15 Lyman break analogue galaxies which appear to exceed the star formation surface density in typical high redshift galaxies by more than order of magnitude. These are relatively bright, but were selected to mirror galaxies in the distant Universe in mass, star formation rate and metallicity. Such intense starbursts could yield insights into the physical processes and conditions in some of the most distant starbursts currently observable and into the star-formation driven winds which drive reionization and metal enrichment of the IGM. Here we request spectrally and spatially resolved imaging in the CO(1-0) transition in order to evaluate the size, dynamical mass, merger status and possible gas masses in these systems. We will interpret these in the context of our existing optical and near-IR spectroscopy, radio data and multiwavelength spectral energy distribution information. We will use these to accurately derive their star formation rate density, and determine whether the sources show multiple components or disturbed morphology, facillitating direct comparison with populations of Lyman break galaxies at z>5. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2018-11-25T00:43:05.000 |
| 798 | 2018.1.01852.S | 79 | Resolving the molecular and atomic gas content of galaxies beyond the local Universe | We propose to image the molecular gas and dust in 14 galaxies between 0.11 | Surveys of galaxies | Galaxy evolution | 2020-07-29T11:12:24.000 |
| 799 | 2012.1.00812.S | 5 | Shock dissipation in the Antennae merger: from Super Giant Molecular Clouds to pre-Cluster Clouds | We propose to map shock excited molecular gas in the overlap region of the Antennae merger, at sub-arcsecond resolution. The observations target lines of SiO, HNCO and CH3OH in bands 3 and 6. These unprecedented data on molecules known to be shock tracers will probe the dissipation of the gas turbulent kinetic energy in different density environments. This project follows up the detection of shock powered (rather than fluorescence) H2 near-IR line emission from super giant molecular clouds and two luminous compact molecular clouds not associated with any known SSC.The proposed ALMA observations will provide the combination of spectral and spatial resolutionrequired to test our interpretation of the H2 observations. The detection of SiO, HNCO and CH3OH emission will be unambiguous evidence of energy dissipation in shocks driven by the mergers dynamics. The observations give acces to the sizes and dissipation timescale necessaty to test our putative identification of the compact H2 sources as progenitors of SSCs. This proposal is part of coordinated team effort linking observations to state-of-the-art modelling of interstellar chemistry in MHD shocks and numerical simulations of formation of stellar clusters in turbulent clouds. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-10-31T08:05:16.000 |
| 800 | 2022.1.00225.S | 30 | The Origins of Protostellar Multiplicity: Searching for Massive, Gravitationally Unstable Disks | An ALMA survey of 328 Orion protostars at 0.12" resolution has resolved Class 0 and I protostellar disk candidates that are massive enough to be gravitationally unstable. However, the current data do not have the resolution to detect substructure indicative of gravitational instability (GI), nor are those data able to provide constraints on the protostar masses. We propose to observe 5 protostellar disks from that survey to search for signatures of GI at 0.03" resolution (12 au), a factor of 4 improvement. These disks are among the most massive and most extended in the entire Orion sample. With these data, we aim to determine the feasibility of close multiple systems forming via disk fragmentation by assessing the stability of the proposed disks. To assess the disk stability and the feasibility of angular momentum transport via GI, we will also measure the masses of the protostars using C18O and 13CO molecular lines. Disks showing signs of gravitational instability i.e., clumps and spiral arms driven by self-gravity without fully formed companions have eluded observation thus far, and these are the 5 most promising disks in Orion to search for such features. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2024-07-10T12:21:25.000 |
| 801 | 2016.1.00875.S | 151 | Formation, State, and Structure of all Major CMZ Clouds | Studies of molecular clouds in the Central Molecular Zone (CMZ) of the Milky Way allow exploration of star formation under extreme conditions. This will help to refine star formation theory, but it also informs our understanding of starbursts and the centers of galaxies. Our Galactic Center Molecular Cloud Survey (GCMS) just used the SMA to observe, for the first time, all major CMZ clouds at interferometer resolution. This gives a first --- but limited --- overview of the properties of dense substructure in CMZ clouds. In a pilot study of the cloud G0.253+0.016 (the "Brick") we have now shown that ALMA teaches important additional lessons about the density structure (from dust continuum), temperature structure (from H2CO), kinematics (from SiO tracing shocks), and the densest and coldest gas (from DCN) of the clouds. These data provide extensive constraints on the structure, state, and formation of CMZ clouds. The observations requested here will constitute the most comprehensive survey of CMZ molecular clouds yet. This economic project (4 hours of main array time) will greatly help to lead CMZ research towards work on more representative cloud samples. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-05-14T00:00:00.000 |
| 802 | 2019.1.00343.S | 9 | Unveiling the dust properties of z>8 galaxies | Determining when the first galaxies emerged from darkness in the early Universe is one of the outstanding quests of cosmology. However, until the launch of JWST, it is not possible to directly observe sources beyond a redshift z~11. A possible indirect method to determine the extent of star-formation prior to this observational horizon is to measure the dust content of the most distant known sources. Since dust at early times reflects the nucleosynthetic product of massive stars which exploded as Type SNe, it provides a valuable estimate of the star formation prior to the epoch of observation. Unfortunately, the inferred dust mass depends strongly on the dust temperature, a property poorly constrained or not at all at z>6. We propose to obtain deep ALMA band 8 observations for two well-studied spectroscopically-confirmed z~8.3 galaxies with a single-band dust detection, in order to determine more reliable dust temperatures and hence better estimates of star formation history at yet earlier times. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-10-25T17:29:01.000 |
| 803 | 2021.1.00207.S | 80 | H-drop galaxies: ``Rosetta Stones'' at z>12 for galaxy formation studies | We propose observations of the [OIII]88um emission lines for secure candidates of luminous Lyman break galaxies at z>12. These galaxies were found in an H-band dropout selection to search for unprecedentedly high-z objects at z>12 in the 2.3 deg2 near-infrared deep imaging data in the COSMOS and UDS fields. After careful examination of non-detections in the deep optical to H-band images as well as the flat spectrum from K-band to Spitzer IRAC [3.6] and [4.5]-bands, only two candidates remain. The absolute magnitudes of these objects are typically -23.4 and the photometric redshifts are estimated to be z>12. An ALMA DDT program targeting one of the candidates shows a tentative [OIII]88um emission line at z=13.27, but deeper observations are needed to confirm the redshift. A successful detection of the [OIII]88um from at least one object among them will yield the new redshift record far from the current ones at z=9.11 and z=10.96. These z>12 galaxies are luminous enough to be followed-up with ALMA and JWST and will be ``Rosetta Stones'' for galaxy formation studies, once their redshifts are determined. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-05-06T17:11:23.000 |
| 804 | 2022.1.01792.S | 42 | AGN feedback in action: molecular gas in the host of remarkable outflowing unobscured QSO | The connection between Active Galactic Nuclei (AGN) and their hosts is an essential piece of galaxy evolution models. Major galaxy mergers are thought to bring large amounts of gas to the central regions, triggering quasar activity. This can result in powerful outflows that clear the circum-nuclear region, making the quasar pass from an obscured to an unobscured phase while possibly affecting the whole host galaxy. A population of typeI (unboscured) high-z quasars with multi-phase outflows has been recently discovered based on optical detection of proximate H2 absorption and leakage of Lya emission. At the same time, mm-observations of these quasars reveals large molecular reservoirs in CO emission with wide kinematics (300-1000 km/s). These quasars are Rosetta stones to study early quasar feedback where favourable orientation reveals the nucleus almost unobscured as outflows have pierced through the circum-nuclear region. We propose high angular resolution observations of CO3-2, CO5-4 and CO7-6 to fully understand the nature of such systems (host, outflow and companion galaxies) through exquisite information on the molecular gas (distribution, kinematics and excitation) and dust. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-10-04T17:24:16.000 |
| 805 | 2013.1.00828.S | 7 | Circumnuclear Disks and Black Hole Masses in Nearby Radio Galaxies | It has long been anticipated that ALMA will provide new measurements of central black hole (BH) masses in active galaxies, and we are now at the threshold of an exciting new era in which these measurements are just becoming feasible. The goal of this proposal is to examine the molecular gas distribution and kinematics in two nearby radio galaxies, NGC 4261 and NGC 4374 (M84). Both galaxies are already known to harbor rotating circumnuclear gas disks on 100 pc scales, and the black hole masses in these galaxies have previously been measured via HST observations of the ionized gas kinematics of the disks. However, the interpretation of ionized gas kinematics is complicated by the large turbulent velocity dispersion observed in the ionized component, while the cold molecular gas is likely to be more quiescent and a better tracer of the central mass distribution. We will use ALMA observations of CO(2-1) at subarcsecond resolution to determine the spatial and kinematic structure of the disks, to examine the relationship between the molecular and ionized gas kinematics, and to carry out dynamical modeling of the disks to derive new constraints on the BH masses. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2016-11-01T05:42:00.000 |
| 806 | 2016.1.00423.S | 2 | Towards solving the Sun's chromospheric/coronal heating problem | How are the outer layers of the Sun heated to temperatures in excess of a million kelvin? This so-called coronal heating problem is a fundamental long-standing question central to contemporary solar physics with direct implications for all stars that exhibit a corona. Over the years, many mechanisms have been proposed that could transport the energy required to explain the observed temperatures from the solar interior into the outer layers. The complicated dynamic and intermittent nature of the solar atmosphere makes it challenging to identify the most important mechanisms and to quantify their heating contributions. This task requires very accurate observations at high spatial, temporal and spectral resolution, which give rich information on the thermal, kinetic and magnetic state of the solar atmosphere. So far, obtaining the required data sets was impeded by the limitations of the few accessible diagnostics. ALMA is now offering unprecedented diagnostic tools that will eventually produce the needed measurements. The proposed high-cadence observations of Quiet Sun and Active Region targets will be used as an integral part of an ERC-funded project (PI: S. Wedemeyer). | The Sun | Sun | 2018-07-06T21:47:05.000 |
| 807 | 2018.1.01831.S | 58 | Atomic Carbon - The UV story of heating and cooling in low-mass protostars | Stars are born in a dramatically dynamic environment, where accretion heats the envelope and outflows interact with the surrounding gas in shocks. Herschel observations highlighted that irradiated shocks are common in low-mass protostars, emphasizing the role of UV radiation in the heating and cooling balance of young protostars. With ACA standalone Band 8 observations we aim to observe atomic carbon -- an excellent UV field tracer -- in the Serpens SMM1 protostar system, known to have a rich far-IR spectrum and expected to host a powerful UV field. With the resolution of the ACA, we can identify the origin of the carbon emission and use it to trace the UV generated in the physical components in the system, such as the outflow cavity, internal working surfaces of the molecular jet or the accretion shock near the protostar. We will test how the UV field measured with [C I] compare with the one inferred from far-IR lines. | Outflows, jets and ionized winds | ISM and star formation | 2020-08-31T09:28:10.000 |
| 808 | 2015.1.01114.S | 45 | Chemical Variation in a Barred Spiral Galaxy NGC 3627 | An astrochemical approach is now becoming a standard method to study environmental conditions not only in Galactic sources but also in external galaxies. A potential application of the astrochemical approach is studies of star-formation feedback to molecular clouds. Since a chemical composition is sensitive to current and past environmental conditions which cannot readily be studied by conventional observations with the CO lines, it can be used to highlight the regions affected by star-formation feedback. In this program, we will test this idea in the barred spiral galaxy NGC3627 with the high spatial resolution (~80 pc) of ALMA. NGC3627 has a vigorous H II regions at the bar end, and is an ideal target to explore the chemical composition influenced by the star-formation feedback. By comparing the chemical compositions of the bar end with those in the spiral arm and the bar, we will be able to establish the star-formation feedback effect on chemical compositions. The result will be a fundamental base for astrochemical diagnostics of external galaxies. | Galaxy chemistry | Galaxy evolution | 2017-07-07T20:06:23.000 |
| 809 | 2013.1.00658.S | 10 | Hunting for gaps in HEABE disks | Gaps in disks are a signpost of disk dispersion and planet formation, but finding disk gaps is challenging. Spectral Energy Distribution (SED) studies do not provide unequivocal evidence for gaps, especially in disks around higher mass Herbig AeBe stars. Recently it has been shown that many of these Herbig stars classified as flaring are in fact disks with developing or fully cleared large gaps. We propose to image three flaring HAEBE disks for which strong indirect evidence of such gaps exists. Our proposal will increase the number of Herbig disks with proven gaps by 3 and deliver constraints on the evolution planet-forming potential of these disks. | Disks around high-mass stars | Disks and planet formation | 2016-11-03T05:56:43.000 |
| 810 | 2016.1.01089.S | 0 | Mapping Magnetic Fields in the NGC 1333 IRAS 4A Jets: Are Protostellar Jets Driven by Magnetic Fields? | Magnetic fields are believed to play a fundamental role in the magneto-centrifugal mechanism of protostellar jet formation. Despite the central prediction of the theory that the magnetic fields in jet are predominantly toroidal, the toroidal fields in jet have rarely been detected before. The magnetic fields in low-mass protostellar jets can only be detected via molecular line polarization. We have carried out SMA CO (3-2) polarization observations in NGC 1333 IRAS 4A. The SMA CO (3-2) polarization map reveals helical magnetic fields in the outflows, which are likely the fields produced by the jet-envelope interaction. Here we propose follow-up ALMA CO (2-1) and SiO (5-4) polarization observations to map the magnetic fields in the jets of NGC 1333 IRAS 4A. The proposed observations offer a chance to reveal the geometry and strength of the magnetic fields in the jets. Since jets are more likely driven directly by the accretion disk than the outflows, this project would provide the first direct test of the magneto-centrifugal mechanism. In addition to the line polarization, we will use C18O (2-1) to search for a Keplerian disk in NGC 1333 IRAS 4A down to a radius of 70 AU. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-01-05T14:48:45.000 |
| 811 | 2018.1.01822.S | 37 | Molecular Gas in a Blue Compact Dwarf Galaxy | The main goal of this proposal is to map the blue compact dwarf galaxy UM 465 in 12CO(1-0), 12CO(3-2), and dust continuum at 870 microns. Understanding the star-forming, molecular gas in blue compact dwarf (BCD) galaxies remains one of the leading challenges in the field of star formation. Key unresolved questions include: How do the environments of these galaxies influence the properties of their giant molecular clouds (GMCs), the sites of all observed star formation? Does the relatively low CO luminosity of dwarfs suggest that they have a higher molecular star formation efficiency? Or is CO emission not the best tracer of molecular gas in metal-poor systems, where reduced dust shielding may result in significant reservoirs of dark" molecular gas not traced by CO? By mapping UM 465 in CO and dust continuum, the main hypotheses we aim to test are: (1) The physical properties of GMCs in BCDs, such as size, mass, and velocity dispersion|are very different from the properties of local GMCs in the Milky Way. (2) Dust continuum emission is an overall more effective tracer of molecular gas in BCDs | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2020-08-07T03:58:55.000 |
| 812 | 2019.1.00244.S | 150 | Constraining the Assembly of Massive Galaxy Clusters with Extreme Starbursts | Recent discoveries of z>2 protoclusters that are abnormally rich with dusty star-forming galaxies (DSFGs; SFRs>100Msun/yr) represent progenitors of galaxy clusters that are undergoing an extreme phase of active star formation. How unusual are DSFG-rich protoclusters? These environments are ideal laboratories to study the early phase of cluster formation and how galaxies in clusters build their mass: whether it be stochastic and correlated over very large physical scales ~15 Mpc (comoving), or largely locally-driven and simply accelerated with respect to galaxies in the field. Here we propose to obtain spatially resolved CO(3-2) and CO(4-3) maps (with 0.3 resolution) for a total 15 DSFGs in three well-known protocluster environments at 2.1 | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2022-10-28T23:26:52.000 |
| 813 | 2021.2.00006.S | 36 | High-frequecy radio observations of IXPE targets | Multiwavalength polarization, and in particular X-ray polarization, can be an important probe of the magnetic field geometry, acceleration physics, and high-energy emission processes of blazar jets. The Imaging X-ray Polarimetry Explorer (IXPE) will soon (December 2021) open a new window to the Universe through high-energy polarization. Here we propose high-frequency monitoring of IXPE blazar targets. The proposed observations will supplement our planned multiwavelength campaign in radio, optical, X-rays, and gamma-rays. Measurement of the mm-optical-UV-X-ray continuum spectra of blazars in conjunction with X-ray polarization will provide the data needed to determine, for the first time, the mechanism and location of the X-ray emission, as well as test particle acceleration models in blazar jets. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-05-10T11:49:33.000 |
| 814 | 2021.1.00736.S | 30 | Blowing in the Wind: Temporal Variability of Titan's High-Altitude Circulation System | ALMA observations of Titan in 2016 and 2017 revealed the presence of a surprisingly fast, strongly time-variable zonal wind/jet encircling the equator at high (thermospheric) altitudes. This unexpected discovery presents a major challenge for our understanding of how momentum is transported throughout the atmospheres of terrestrial-like planets. Here we propose multi-epoch, high resolution Doppler wind measurements of HNC, HC3N, CH3CN and C2H5CN in Titan's mid-to-upper atmosphere, to provide maps of the wind velocity field in four dimensions (latitude, longitude, altitude and time). This data will allow us to (1) determine the intrinsic cadence (and magnitude) of temporal variability in Titan's zonal winds, (2) investigate the origin, evolution, and stability of the newly-discovered thermospheric jet, and (3) by comparison with new and state-of-the art climate models, determine the detailed mechanisms responsible for high-altitude energy and momentum transport, and their impact on the observed wind speeds. This work will to pave the way towards a new understanding of seasonal variations in the dynamics of rapidly rotating, terrestrial-like planetary atmospheres. | Solar system - Planetary atmospheres | Solar system | 2024-07-25T18:48:15.000 |
| 815 | 2024.1.00876.S | 0 | Heart of Darkness: The Deepest Intrinsic ALMA+JWST Glimpse of the Early Universe | We propose to observe the highly magnified galaxy cluster AS1063 with deep Band 6 ALMA observations (1sigma=22uJy) complemented by the deepest JWST photometry to date (33-35 mag at 1-5um), 2-4 mag deeper than existing field observations. This will enable us to probe the faintest rest-frame optical and dustiest sources in the epoch of Reionization. Covering the 2'x2' cluster center with continuous 30GHz spectral scans, our project aims to detect 40 lensed ALMA continuum sources (x2 the number in typical field observations) all with ultradeep JWST imaging, and ~6,000 dusty lensed NIRCam sources from z=1-9. We will analyze faint dust emission, assess the contribution of the faintest and most dust-obscured sources to cosmic SFR density, detect cold dust in little red dots, and define the faint-end of the [CII]-SFR relation down to ~1Msun/yr at z=6. We will waive the 1-year proprietary period and plan to release reduced continuum maps and line cubes in early 2025, concurrent with JWST data release. This combination of gravitational lensing, deep ALMA, and deep JWST observations will offer unparalleled insight into the dust properties of the faintest galaxies in the early Universe. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 816 | 2016.1.01573.S | 17 | Abell 2533 - The bullet from a smoking gun? | We request a single Band 3 observation of CO(1-0) in a core of remarkable cluster of galaxies, Abell 2533. Our recent VLT MUSE observations of this cluster identify a long (40kpc), almost linear filament of optical line emission that passes across the centre of the brightest cluster galaxy. We outline several possible explanations for this morphology (merger with a cluster member, AGN-drived outflow and gas cooling from intracluster gas `sloshing' around the cluster core) that from the MUSE data alone are all plausible. With the addition of an observation of the cold molecular gas we are confident that we can disentangle these three alternative explanations. Our strong suspicion is that the gas cooling is the most likely given recent ALMA observations of less extreme clusters but the evidence is only circumstantial without the CO data. Whichever explanation is found to be most plausible the implications of the result will be significant and be far reaching. | Merging and interacting galaxies, Galaxy groups and clusters | Galaxy evolution | 2018-04-28T03:07:08.000 |
| 817 | 2016.1.00877.S | 25 | RW Aurigae: Probing the Aftermath of an Eccentric Star-Disk Fly-By | We propose observations of RW Aur, a young binary system thought to recently have gone through a close encounter of the two stars, which stripped away part of the primary's disk, resulting in a large tidal tail. We will test the fly-by model (which our group has extensively modeled) by measuring the structure of the tail, determining if it forms a kinematically coherent structure with the primary's disk, and searching for predicted asymmetries in the primary disk, which will be spatially resolved for the first time. In addition, we may be able to detect the secondary's disk (which may have been disrupted by the putative encounter), and we will search for other interesting chemistry and spatial structure that may appear in these observations, which will be much more sensitive than previous mapping of this system. | Disks around low-mass stars | Disks and planet formation | 2018-03-17T00:45:43.000 |
| 818 | 2013.1.00976.S | 3 | The first millimeter detection of an ultracool dwarf | Although ultracool dwarfs (UCDs; very low mass stars and brown dwarfs, >M7) are fully convective and so cannot sustain a solar-type dynamo, they are now known to be magnetically active. While radio observations have proven to be uniquely rich probes of UCD magnetism, a fundamental question — what is the radio emission mechanism? — is not satisfactorily answered. We have recently obtained multi-band (1.4–43 GHz) VLA observations of the benchmark radio-active UCD NLTT 33370 AB, confirming the unusual nature of its emission, most notably its extremely flat spectrum and variability. We propose to study a complete rotation of this object in full polarization with ALMA’s band 3. The data will clarify the emission mechanism via its polarized spectrum, yield the first millimeter detection of a UCD, and characterize this object’s variability at previously-inaccessible wavelengths. These results will diagnose the magnetic field strength and other physical conditions at the emission site, and potentially set the stage for spatial resolution of the binary at higher frequencies. | Main sequence stars, Brown dwarfs | Stars and stellar evolution | 2018-02-17T00:00:00.000 |
| 819 | 2023.1.00908.S | 0 | Testing grain alignment of carbonaceous envelope of an AGB star IRC+10216 | A quantitative understanding of interstellar grain alignment is finally within reach, which will allow reliable probes of magnetic fields and grain characteristics. In Radiative Alignment Torque (RAT) theory, grains are spun-up by radiation. For paramagnetic grains this induces a magnetization, causing alignment with the magnetic field. RAT theory also explains that carbonaceous grains are unaligned because carbon solids are diamagnetic, which, while spun up by the radiation, are not magnetized and dont sense the magnetic field. In the ISM the dust components are however mixed, complicating testing these predictions. We will probe the dependence of grain alignment on the dust mineralogy using ALMA polarimetry of the chemically well characterized, "pure", circumstellar envelopes of a C-rich AGB star IRC+10216. This is a reproposal of an accepted, but unexecuted, Cy 9 program. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 3000-01-01T00:00:00.000 |
| 820 | 2019.1.00037.S | 4 | Magnetic Fields or Grain Growth: Polarized Emission from a Young, Edge-on Protostellar Disk | Protostellar disks are likely threaded by poloidal magnetic fields, since flux is dragged inward as the disks form by the collapse of their parent molecular cloud cores. The fields if strong enough are the key to the disks' evolution and jet launching. However, direct evidence for magnetic fields has been lacking. With ALMA, we may have detected poloidal fields in the young edge-on disks of two nearby protostars, HH 212 and HH 111, via polarized thermal dust emission. We now propose polarization observations at two longer wavelengths, to determine whether the polarization is due to magnetic fields, or instead comes from scattering of the dust's own thermal emission. Since mapping the polarization is time-consuming, we will first target only the HH 212 disk, observing at 225 GHz in Band 6 at 0.05" resolution and 105 GHz in Band 3 at 0.06" resolution. Detecting a poloidal field would give the first solid foundation for current models of disk evolution and jet launching. Finding that the polarization instead comes from self-scattering would cast doubt on the magnetic models, and provide fresh information on grain growth during the early stages of planet formation. | Outflows, jets and ionized winds | ISM and star formation | 2023-01-17T08:50:14.000 |
| 821 | 2022.1.01360.S | 0 | Circumplanetary Disk Emission from the Accreting Protoplanet Candidate AB Aur b | Giant planets build their mass by accreting material from circumplanetary disks. This epoch of planet growth is challenging to study with direct imaging because of the small angular resolution and high contrasts required. Moreover, compact disk features can mimic accreting planets by scattering emission from the host star, which can greatly complicate the interpretation of point sources. Recently a protoplanet candidate was imaged inside the transition disk of the young Herbig Ae/Be star AB Aurigae. We propose to test whether AB Aur b is an accreting planet or a scattered light disk feature by searching for dust emission from a circumplanetary disk with deep, high-resolution ALMA Band 7 continuum and CO line observations. This rich dataset will also be used to search for other planets in the system, assess dynamical evolution of disk substructures, and probe the physical properties of any detected circumplanetary disks. If confirmed, AB Aur b would explain many substructures in the AB Aur disk and would represent only the second direct detection of a circumplanetary disk within a transition disk after PDS 70 c. | Exo-planets | Disks and planet formation | 2025-01-10T14:04:16.000 |
| 822 | 2021.1.00421.S | 292 | The impact of accreting black-holes on the star-forming ISM | A current challenge in the study of the ISM at high redshift is the lack of reliable molecular gas tracers. Studies based on CO rely on the observations of excited states (CO, J>5), which are difficult to interpret due to our poor understanding of the CO spectral line energy distributions (SLEDs) in the early Universe - particularly at high excitation CO states, and for galaxies hosting AGN. We propose to complete our Cycle 7 program, and build a library of CO SLEDS (38 transitions for all of them, exploring a parameter space in excitation not covered to-date. We will link the impact of AGN on the properties of the ISM (excitation, temperature and density), test theoretical models for star forming galaxies, and calibrate CO line ratios at high-z. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2024-03-12T00:00:00.000 |
| 823 | 2019.1.01400.S | 143 | A Quest for the Formation Mechanism of Molecular Filaments | It is a longstanding question how molecular filaments are formed. Recent numerical simulations proposed that the formation of molecular filament requires multiple episodes of supersonic compression such as supernova shocks or stellar winds. W28 is the most famous supernova remnant associated with shocked molecular clouds. Most recently, we revealed many filamentary structures of molecular clouds in the northeastern edge of W28. However, we could not resolve the filaments with sufficient spatial resolution. Moreover, we could not derive physical properties of the filaments due to luck of optically thin data such as 13CO line emission. Here, we propose 13CO(J=2-1) observations toward the molecular filaments associated with W28 using the ALMA stand alone ACA mode with an angular resolution of ~5.7 arcsec (~0.05 pc resolution at the distance of W28). ALMA's unprecedented sensitivity and spatial resolution will allow us to study the 0.1 pc-scale molecular filaments interacting with SNR's shocks for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-06-23T19:36:57.000 |
| 824 | 2017.1.00112.S | 55 | Do z~2 quasar-driven outflows really suppress star formation? | Despite two decades of model predictions that the most luminous AGN (i.e., quasars) can have a significant impact upon the star formation in their host galaxies, the observational results that directly confirm these claims are limited and are usually very speculative. However, ``direct" evidence for star formation suppression have been presented using IFU data for three z~2 quasars. In all three objects, these data show an anti-correlation between high velocity ionised outflows and the unobscured star formation, as traced by [O III] and narrow H-alpha emission respectively. However, our recent work combining high-resolution ALMA continuum emission, tracing obscured star formation, with tracers of unobscured star formation (such as H-alpha) has highlighted the dangers of interpretations on the total star formation in the absence of obscured star formation constraints. Here we propose an observational test to the often-cited claims of star-formation suppression, by obtaining deep 870um ~0.3" resolution continuum maps to trace the obscured star formation in these three quasars. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-09-10T15:10:45.000 |
| 825 | 2012.A.00040.S | 0 | The assembly of a primeval galaxy 740 Myr after the Big Bang revealed by ALMA v3 | In Cycle 1 we have detected (at 7.2sigma) the [CII]158um line in a star forming galaxy (LBG) at z=7.1, well within the reionization epoch. This is the most distant far-IR detection obtained so far and, in contrast to other high-z [CII] detections, in a galaxy with modest star formation rate (SFR ~ 9 Msun/yr), representative of the population at this epoch, likely responsible for the reionization of the universe. The [CII] line is extremely narrow, FWHM~8km/s, although resolved on three independent ALMA channels. The [CII] emission is also spatially offset, by 3 kpc (~0.5"), relative to the Lya+UV emission. These properties ([CII] narrowness and offset) are in very nice agreement with the expectations of models of primeval galaxies. Indeed, models were predicting that primeval galaxies are completely ionized, while low mass clumps of neutral cold gas orbiting and accreting onto the main galaxy, that should be detectable as [CII] narrow emission. This is the first direct observational confirmation of models of primeval galaxies. The result has been submitted to Nature. Although both editor and referees are enthusiastic, one of the three referees has asked us to increase the significance of the detection through a DDT proposal. Hence we hereby ask to repeat the same observation, to reach a total significance of the [CII] detection (together with our previous observations) of 10sigma, which would secure the publication on Nature and make this one of the most spectacular results of ALMA. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2014-12-09T14:39:56.000 |
| 826 | 2015.1.00168.S | 48 | Volatiles in protoplanetary disks - Tracers of thermochemistry, and transport? | Here we propose to carry out a 0.4-0.5 arcsecond imaging survey of the HCN 4-3 and CO 3-2 lines in a carefully selected suite of protoplanetary disks with intense, well characterized near- through mid-infrared molecular emission from water vapor, organics, and carbon monoxide. Combined with detailed radiative transfer models, the full data sets will accurately constrain the molecular abundance gradients and volatile elemental ratios throughout the disks. The locations of the frost lines and the abundance jumps across them should provide our first detailed glimpses into the underlying transport dynamics of gas and solids, and only ALMA can provide the necessary angular resolution and sensitivity needed to connect the short- and long-wavelength probes of the gas in the inner and outer disk. Efficient correlator settings in Band 7 enable isotopologues of CO and HCN to be imaged at the same time as the parent species, along with several other important tracers of disk chemistry. This program modestly expands upon observations presently scheduled as Priority C filler in Cycle 2, and any such AOTs acquired in CY2015 will reduce the time required for this program accordingly. | Disks around low-mass stars | Disks and planet formation | 2017-10-12T00:15:11.000 |
| 827 | 2017.1.00829.S | 19 | Channelling Phosphorus into Planets: Towards Habitability | Phosphorus is one of the 'CHNOPS' elements needed for life (as we know it) to function. As part of a project tracing P from its sources in supernovae to its entry into planets, we propose to make the first search for P-bearing molecules in a proto-planetary disc. We will search for PO, PN, CP and PH3 which are already identified in cloud cores and stellar envelopes. Our prototype disc is Oph IRS 46, which is already known to contain organic molecules and astrophysical ices, and where the active stellar host can promote release of frozen-out phosphorus into the disc gas. The ALMA data will be sensitive down to the mass of phosphorus estimated in Jupiter and Saturn. Hence we wil be able to explore whether an analogue to the proto-solar nebula has the potential to form phosphorus-rich planets. | Disks around low-mass stars | Disks and planet formation | 2019-10-19T21:54:28.000 |
| 828 | 2019.1.00685.S | 5133 | On the origin of the dense gas star formation law in Galactic high-mass star forming clumps | In pioneering works (Gao & Solomon 2004; Wu et al. 2005), people found that the far-infrared luminosities in starburst galaxies and/or Galactic massive clumps followed a very tight, linear correlation with the luminosities of dense gas tracers like HCN (i.e., the dense gas star formation law). However, the origin of this correlation is far from well understood. Here we propose to use ALMA to systematically investigate the spatial distribution of various dense gas tracers in 146 proto-clusters in order to understand the origin of the dense gas star formation law. We aim to: (1) study how core formation efficiency (CFE) in proto-clusters changes with clump-averaged conditions and Galactocentric distances. (2) investigate the spatial distributions of various dense gas tracers to see how much of the total line luminosities of clumps come from dense cores, how much from unbound structures and how much from sub-thermal emission in very low density regions. (3) investigate how globally collapse and stellar feedback influence CFE and the distributions of dense gas in proto-clusters. | High-mass star formation, HII regions | ISM and star formation | 2021-03-17T13:03:30.000 |
| 829 | 2023.1.00837.S | 0 | Hidden in plain sight: dynamical mass estimates for a newly-discovered red monster at zspec~5.6 in the GOODS-S field | A surprising result of early JWST observations was the discovery of several extremely massive galaxies up to z~8 challenging the standard LCDM model. However, the lack of spectroscopic redshifts and inherent uncertainties of SED fitting sparked a debate about a possible overestimation of stellar masses. The only way to resolve this tension is dynamical masses. Here, we propose to do exactly this for an even more extreme galaxy at zspec=5.58 discovered in deep JWST images and spectra. It is extremely red and massive - almost Milky Way mass already at 1Gyr after the Big Bang - and has a very extended dust distribution (ALMA 1.1mm size ~6 kpc). This monster was hiding in plain sight in the GOODS-S field. Despite 30 years of observations, it was only now revealed thanks to ALMA and JWST. We propose partially resolved [CII]158um emission line observations: the most efficient approach to obtain its dynamical mass, total star formation rate, and gas distribution. This is the only way to test its overly massive nature within LCDM, study the formation of such extended dust (and/or gas) distributions, and understand the formation of extreme sources in the first 1Gyr of the Universe. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2025-01-22T18:40:16.000 |
| 830 | 2016.A.00014.S | 33 | Completing the Picture of Titan's Time-Variable Atmospheric Chemistry on Cassini's Last Flyby | Titan's atmosphere is host to a complex organic chemistry and high-altitude circulation system with strong seasonal variability. During the last two years, a dramatic decrease in the abundances of short-lived trace gases (such as HC3N) has been observed over Titan's north pole by the Cassini CIRS infrared spectrometer. The speed of this seasonal change has only become apparent in the latest observations (after the Cycle 4 deadline). Such rapid chemical variations provide a unique opportunity to observe the complex interplay between atmospheric chemistry and dynamics in a carbon-rich (reducing) atmosphere, which may be used as a template for other primitive planetary atmospheres, including exoplanets. We propose to measure these atmospheric phenomena using a combination of contemporaneous, spatially-resolved observations with ALMA and Cassini. Combined with CIRS hydrocarbon observations, ALMA observations of HCN, HNC, HC3N, CH3CN, C2H3CN and C2H5CN (plus CO) will probe the atmospheric chemical loss and diffusion rates, to test theories for the production of Titan's complex organics and haze. Our proposed DDT observations will be timed to coincide with the May 2017 Cassini flyby. | Solar system - Planetary atmospheres | Solar system | 2018-05-23T00:00:00.000 |
| 831 | 2017.1.00753.S | 21 | Revisiting the star formation efficiency of low-metallicity starburst galaxy NGC5253 | With its supermassive star clusters, high star formation (SF) efficiency and low metallicity, NGC5253 is the best local laboratory to study star formation conditions at high redshift. The offset of the Kennicutt-Schmidt law may be indicative of a non-standard mode of star formation, but this inference critically depends on the determination of the star-forming gas reservoir, which is currently incomplete due to very opaque clouds (AV=50mag) and the absence of CO-dark gas tracers. We propose to observe [CI]1-0, 13CO(2-1), 12CO(1-0) and C18O(2-1) lines with ALMA in 7h at high spatial resolution (0.25" or 4pc) to recover the total molecular gas content. We will be able to reanalyse the SF efficiency, and conclude whether the high SF efficiency can be explained by the presence of a large CO-dark gas reservoir or requires a non-standard mode of star formation. Based on high-resolution line diagnostics from archival databases, we will construct a multi-phase ISM model and constrain filling factors for the various ISM phases. The quantification of the CO-dark gas fraction and the calibration of various line diagnostics will be crucial for high redshift studies of star-forming galaxies. | Starbursts, star formation | Active galaxies | 2019-04-19T17:02:45.000 |
| 832 | 2018.1.01585.S | 196 | Revealing the spatial distribution of CH3OH toward Class I protostellar envelopes | In low-mass star formation, the infalling envelope contribuites to the growing central star and to the formation of the disk. This envelope provides an efficient shielding from interstellar UV radiation and, thus, the perfect conditions for the formation of complex species, that later on can be delivered to the disk and future planetesimals. Methanol (CH3OH) is the simplest organic molecule and a crucial path for the formation of more complex species. CH3OH is readily observed toward Class 0 envelopes, where non-thermal mechanisms enhance its abundance in the gas phase at low temperatures (< 80 K). However, it is surprisingly absent toward Class I sources, where it is observed at large spatial scales (~ 4000 AU) but not on disk sclaes (~ 200 AU). The main goal of this proposal is to map the spatial distribution of CH3OH in a sample of Class I sources, probing material from the envelope to outer-disk scales. These observations will explore the contribution of the envelope to the formation and evolution of the star/disk system and the physical conditions for the formation of more complex species. | Low-mass star formation | ISM and star formation | 2020-10-17T19:07:37.000 |
| 833 | 2021.1.00535.S | 45 | High resolution observations of deuterated hydrocarbons in protoplanetary disks | Deuterium enrichment is a common phenomenon seen in Solar System material. Because deuterium enrichment is caused by exchange reactions in low temperature environments, it has been inferred that at least some Solar System material could originate from the interstellar medium such as molecular clouds. Deuterium enrichment is expected in the cold outer region of protoplanetary disks as well. Since protoplanetary disks are the birthplaces of planetary bodies, e.g., planets and comets, it is important to investigate deuterium chemistry in disks to understand the origin and thermal history of molecules that are eventually incorporated intoplanetary bodies. The deuterium chemistry in protoplanetary disks is, however, still not fully understood. In this proposal, we will observe the deuterated hydrocarbons C2D and c-C3HD toward three protoplanetary disks. We will resolve the radial distribution of these molecules and molecular D/H ratios as a function of temperature. This allows us to investigate the contribution from multiple pathways to the deuterium enrichment in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2023-07-23T06:09:08.000 |
| 834 | 2016.1.00074.S | 48 | Do branched molecules dominate in the ISM? | ALMA has had a transformational effect on the search for complex organic molecules (COMs) in star-forming regions, pushing the limits of observable chemical complexity. Our recent detection of a branched alkyl molecule in the interstellar medium (ISM) with ALMA has opened a new domain in the structures available to the chemistry of star-forming regions, beyond simple chains. Our astrochemical model was recently expanded to include branched isomers, and indicates that branched molecules may be dominant in star-forming regions where the chemistry is of sufficient complexity. We propose to perform a direct observational test of this hypothesis, in order to determine both the degree and the manner in which chemical complexity evolves during star formation. We propose to search for n-butyl cyanide and its three branched isomers toward Sgr B2(N), the most fruitful target for new detections of COMs in the ISM. The discovery of biologically-relevant molecules in the ISM is of high scientific impact. The combination of our established and productive methodologies with ALMA's unique spectral sensitivity is an ideal match to delve into the newly-discovered chemistry of branched COMs. | Astrochemistry | ISM and star formation | 2018-12-09T00:00:00.000 |
| 835 | 2015.1.01246.S | 16 | Understanding Complex Organic Molecule Formation in Solar-system Precursors | The detection of complex organic molecules (COMs) toward cold sources (T<10 K) such as Solar-system precursors, or pre-stellar cores, has challenged our understanding of the formation processes of complex organics in the ISM. Recent modelling on COM chemistry at low temperatures (T<10 K) however predict that the formation of COMs strongly depends on dust extinction, with its maximum production being found at Av~3-4 mag. The discovery of a low-density and COM-rich shell toward the L1544 pre-stellar core at distances ~50"-60" away from the core's centre (at 8000 AU), offers a unique opportunity to test current theories of COM formation since it coincides with a region with low extinction (Av~3-4 mag). We propose to use ALMA in Band 3 to image the emission from several large COMs such as methyl formate and dimethyl ether, which have recently been detected toward this low-extinction shell. These images not only will establish the spatial distribution, extent and abundance for every COM, but will allow us to pin-point the formation/destruction processes of these species constraining models of COM formation. | Astrochemistry | ISM and star formation | 2017-08-10T21:29:09.000 |
| 836 | 2012.1.00060.S | 3 | Testing Schmidt's Conjecture in NGC 300: Bridging the Gap between Galactic and Extragalactic Star Formation | Understanding the physical factors that control the conversion of interstellar gas into stars is of fundamental importance for both developing a predictive physical theory of star formation and understanding the evolution of galaxies from the earliest epochs of cosmic history to the present time. An important aspect of this question is the study of empirical relations that connect the star formation rate in a given region to local properties of the interstellar medium. An important example is the Schmidt-Kennicutt (KS) law for galaxies that relates the surface densities of the star formation rate and the surface densities of interstellar gas in a non-linear fashion. However, it is also known that there is a linear correlation between the total SFR in galaxies and the mass of dense molecular gas as traced by the high excitation HCN molecule. Contrary to the KS relation, this scaling relation suggests that the total SFR depends simply on the total amount of dense molecular gas in a star forming system. Recently, we have begun to test these scaling relations in the Galactic neighborhood where star formation rates can be much better constrained. We found that for local clouds the total SFR scales most directly, and linearly, with the total mass of high extinction (and dense) molecular gas. Furthermore, we found this linear scaling law between SFR and dense gas to extend and extrapolate directly and smoothly to external galaxies. Moreover, our observations also demonstrate that a KS type relation does not exist for molecular clouds in the Galactic neighborhood. This is a direct consequence of a well known scaling law between the mass and size of molecular clouds, Larson's third law. Overall, our results indicate that a linear scaling law, in which the total amount of dense gas controls the SFR, is the fundamental physical relation that connects star formation across the vast scales from individual GMCs to entire galaxies. Critical testing of these ideas require resolved observations of GMCs in external galaxies. Here we propose to use ALMA to evaluate star formation scaling laws in a nearby galaxy where we can obtain resolved observations of individual GMCs. This allows us to obtain observations of a larger sample of GMCs than is accessible in the Galactic neighborhood. An extensive APEX survey of HII regions in the nearby galaxy NGC 300 has provided us with a sample of 36 star-forming regions with CO(2-1) detections and 42 upper limits. We are currently working on obtaining star formation rates for these regions from multi-wavelength ancillary data including our Herschel observations. We propose to use ALMA's unequalled capabilities to obtain snapshot observations of 40 selected regions in CO(2-1) in order to make resolved measurements of cloud structure to obtain sizes and virial masses. As a pilot project, we also propose to observe the brightest subsample in HCN(1-0) as a dense-gas tracer. Our proposed ALMA CO observations will enable us to to test Larson's scaling laws in an external galaxy and to evaluate which formulation of the Schmidt law is the most meaningful and appropriate to apply to spiral galaxies, and in doing so refine Schmidt's original conjecture of a scaling relation between the rate of star formation and gas density. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2015-08-13T00:00:00.000 |
| 837 | 2012.1.00641.S | 3 | Revealing Internal Structure of Molecular Clouds in the LMC at Various Evolutionary Stages | We propose 12CO J=1-0 mosaic observations of five molecular clouds in the Large Magellanic Cloud (LMC) at a spatial resolution directly relevant to star formation (~1 pc). The ALMA Cycle 1 with the capability of ACA permits resolved studies of molecular gas in the external galaxy for the first time. The present observations provide the high fidelity, high spatial resolution images of the sample of five clouds, which covers a wide range of evolutionary stages based on their associations to recent star formation. We characterize the spatial structure of the gas (e.g., clumpiness), which was found to be tightly related to the evolution of the gas in the Milky Way (MW) in our recent studies, using the new tools we developed. We then examine the difference of the structure of the gas among the clouds (i.e., evolutionary stages and local environments) and between the LMC and the MW. The study will give us the clue to understand the properties of interstellar medium and its influence to star formation in the galaxy where the environment is very different from the MW. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2015-07-11T22:22:18.000 |
| 838 | 2023.1.00468.S | 0 | An ALMA Survey of Lensed SMGs in Three Massive Cluster Fields Observed by JWST | Gravitational lensing by massive galaxy clusters is a powerful tool to probe faint and high-redshift sources at all wavelengths. We propose an ALMA band 7 survey of a uniformly selected sample of 80 intrinsically faint submm galaxies (SMGs) detected by SCUBA-2 within the JWST and HST footprints of 3 massive cluster fields. Using public lens models, the median intrinsic 850um flux of our sample is ~1 mJy, corresponding to SFR~100 Msun/yr. This target sample bridges the SFR gap between rare dusty SMGs and more common UV-selected galaxies, which are essentially disjoint among current samples of bright SMGs. ALMA observations are required to pin down optical/NIR counterparts and deblended fluxes for these faint SMGs, thereby unlocking the rich UV-to-radio multiwavelength data of these cluster fields to tightly constrain the properties of the ALMA-detected sources. The submm flux regime of our large sample will allow us to analyze robustly the properties of this faint SMG population for the first time and to examine the transition (e.g., the critical SFR) below which UV-selected (and corrected) galaxies alone can potentially account for all the star formation as a function of redshift. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-05-16T22:49:33.000 |
| 839 | 2018.A.00051.S | 62 | Mapping Zeeman sensitive moleculaes in the Orion Filament with the ACA | Magnetic fields have been recognized to be of increading dynamical importance in molecular clouds, particularly in star forming regions. However, the only way to measure the magnetic field strength is through the Zeeman effect, which is challenging given the large sensitivity required. Thus, a first step is to find the strongest compact spots of emission from Zeeman sensitive molecules. Here we propose to map the SO and CN Zeeman sensitive molecules, along with continuum, with the ACA in selected regions of the Orion Filament. | Intermediate-mass star formation | ISM and star formation | 2019-09-23T00:00:00.000 |
| 840 | 2022.1.00873.V | 0 | First EHT+ALMA observation of the Cygnus A jet base on 100 Schwarzschild radii scale | Elucidating the jet launching mechanism in active galactic nuclei (AGNs) is one of the most challenging questions in astrophysics. While the jet base of M87, the nearby low-power Fanaroff-Riley I (FR I) jet, has been intensively explored by the Event Horizon Telescope (EHT) over the years, little is known about the detailed jet base structures of the high-power (FR II) jets. Our ultimate scientific goal is to identify the differences between the launching mechanisms of low-power and high-power jets in AGNs. Here we propose a first EHT+ALMA (Band 6) deep imaging observation of the Cygnus A known as the closest (z=0.056) high-power FR II jet. Previous GMVA observations of the Cygnus A jet base have revealed an excessively wide jet base width. The origin of the excess, however, is not yet fully understood. This proposal aims to obtain the first EHT+ALMA image of the Cygnus A jet base on 100 Schwarzschild radii scale to distinguish whether the excess emission comes from the surrounding wind or the accretion disk. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 841 | 2016.1.00784.S | 33 | Tracking the Origin of Dust and Molecular Gas in an Extreme Feedback-Induced BCG Starburst | We propose to acquire spatially resolved imaging with ALMA of the dust and molecular gas in the brightest cluster galaxy (BCG) of the galaxy cluster MACS1931.8-2635, observing CO(1-0) to a depth of 0.18 mJy in band 3 and the dust continuum to 0.08 mJy in band 8. These ALMA observations will, for the first time, map the cold gas and dust at 0.6" (3 kpc) scales, comparable to the size scales of the UV-bright star forming knots and dust lane width in this system. We will also measure the velocity structure of the CO(1-0) tracer at 40 km/s resolution. With these data, we will determine the sources, and distribution mechanisms, of dust in cooled gas in this BCG, characterize the nature of molecular gas flows detected in this system, and constrain the role of dust as a catalyst for star formation and intra-cluster medium cooling. By combining these unique ALMA observations with deep observations from HST, Spitzer, Herschel, Chandra, and archival MUSE IFU data, we will complete a comprehensive study of the multi-phase medium in MACS1931 that will answer unsolved questions about the origin of dust in cool core BCGs and the role of gas physics in AGN-regulated feedback and star formation. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2018-04-07T20:36:19.000 |
| 842 | 2011.0.00808.S | 0 | Probing the vertical structure of Saturn's storm with ALMA | Saturn's usually slowly evolutive seasonal cycle has been disrupted in December 2010 between 20°N and 50°N by the outbreak of an unexpected huge storm system. First Cassini/CIRS and ground-based observations have shown that temperatures, winds and chemistry have been rapidly affected by the storm in the stratosphere. For instance, a temperature increase of 50K over 60° in longitude has been measured by Cassini/CIRS in May 2011. We propose to take advantage of this rare opportunity to use ALMA’s imaging capability during Cycle 0 in band 6 to probe the vertical structure of this unique storm and derive constraints on its formation processes. We will map the CO (2-1) emission to measure the temperature between 0.1 and 10 mbar in the stratosphere and to check for any disturbance in the CO vertical profile. Such disturbance would be due to the injection of massive amounts of tropospheric CO into the stratosphere by the storm. In addition, we propose to try to detect H2S for the first time in the storm, as this species could as well have been transported from the deep troposphere to the stratosphere by the storm. Its observation would provide us with an indirect probe of Saturn's internal sulfur abundance and of the composition of the planetesimals that formed the planet's core. | Solar system - Planetary atmospheres | Solar system | 2013-04-23T12:26:29.000 |
| 843 | 2022.1.01565.S | 27 | Characterizing the sulfur family in low-mass protostars | Sulfur-bearing molecules are commonly observed in both gas and ice near young protostars. Somewhere along the journey from diffuse cloud to protostar, the volatile sulfur budget is depleted by several orders of magnitude. A major uncertainty in this missing sulfur problem is where the sulfur-bearing molecules are being released from the grains and/or formed in high-temperature gas. Here, we propose 0.3-0.6" (50-100 AU radius) Band 6 observations of the main sulfur-bearing species (H2S, H2CS, CS, OCS, SO, SO2, and isotopologues) in a dozen Class 0 and I protostars. The combination of the requested spatial and spectral resolution will allow for disentangling the different physical components (e.g., disk+inner envelope, outflow). By observing optically thin isotopologues, the abundances in each component will be measured, giving a complete inventory of the gaseous sulfur-bearing molecues. These results will be combined with approved JWST/MIRI and NIRSpec programs containing information on the ice abundances and gas-phase atomic sulfur for the same sources. This will allow for the first time to accurately determine the amount of sulfur locked up in unobservable refractory formats. | Low-mass star formation, Astrochemistry | ISM and star formation | 2024-03-10T15:20:54.000 |
| 844 | 2021.1.01432.S | 6 | Studying a spiral to understand AGN feedback in bulges: Can radio jets regulate star formation in galaxies? | Most cosmological simulations postulate today that AGN feedback can lower the star-formation rates in galaxies. This claim has not yet been observationally confirmed, however, in parts, because the low star-formation rates in early-type radio galaxies may also be caused by the structural properties of the bulges. We will observe CO(1-0) and CO(3-2) at 0.4'' beam size in the nearby massive spiral galaxy J2345-0449 at z=0.08, which is the only spiral known with bright radio jets. This opens up a unique opportunity to study the link between radio jets and star formation in a galaxy which has the same structural properties, gas, and stellar mass surface densities as the main populations of star-forming galaxies, a critical test to show whether jets can impact star formation in galaxies. Shallow cycle-7 data show the presence of a 24-kpc large molecular ring which is intercepted by the radio jet, and provide encouraging first evidence of a global lowering of star formation efficiency in this gas. We will now address remaining key questions regarding the true gas mass surface densities, role of outflows and turbulence for star formation, and relationship of rotating vs. perturbed gas. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2023-06-17T02:29:55.000 |
| 845 | 2018.1.00273.S | 38 | Fragmentation & Ambipolar Diffusion in a Filamentary Cloud | Our recent SMA obervations (Li et al. 2010) found that anisotropic turbulence induced by magnetic fields (B-fields) can produce filamentary structures getting aligned with the B-fields in molecular clouds. Furthing this finding, we plan to address the scale relations between fragmentation, turbulence dissipation, and ambipolar diffusion in this kind of filamentary clouds. We propose to observe the filament NGC2024B, an example of filamentary cloud aligned with B-fields, with HCO+ and HCN (3-2) and dust continuum in the same ALMA band 6 at a high resolution of 0.5". A total of 15.6h is requiered for the combined C-43 and ACA configurations. We aim to dicipher three critical aspects of filament fragmentation: whether the fragmentation happens along the B-field in NGC2024B? Whether turbulence-driven ambipolar diusion (AD) results in different fragmentations between ions and neutrals below the AD scale? And how is the fragmentation related to turbulence and B-fields, through turbulence dissipation and ambipolar diffusion? | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-12-21T20:52:33.000 |
| 846 | 2016.1.01530.S | 34 | Detachment of the Torus from the Central Star in a Bipolar Pre-Planetary Nebula | Expanding tori are important in shaping bipolar and multipolar PPNe. Recent studies suggest that different tori induce different driving source. In addition, jet-driven outflow or bullet-driven outflow will change the kinematics of the torus in different ways. A jet-driven model suggests a constant mass-loss rate of the torus with a constant velocity. A velocity linearly increases with distance may suggest an explosive event which produce bullet-driven outflows. Therefore, the study of the torus allows us to examine which model works in the bipolar or multipolar PPNe. We propose to observe a bipolar PPN IRAS 17150-3224 in CO J=3-2, HCN and 345 GHz continuum in Band 7 with a resolution of 0".1. According to our SMA observation in CO J=2-1, the kinematical ages of the torus and the outflow are older than that of most bipolar PPNe. It means a larger expanding distance from the central star, and thus easy for us to resolve the torus. The total observing time is 1.74 hrs (12-m and ACA). The S/N of the CO J=3-2 line of the peak emission is more than 10, with the requested RMS of 6 mJy. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-10-14T20:29:19.000 |
| 847 | 2018.1.00663.S | 12 | Revealing GMCs in a new superbright lensed z=2.04 Submillimeter Galaxy | We propose to characterize GMCs, via ALMA multi-line observations (CO, HCN, [CII]) at 100pc scale, in an ultrabright lensed submillimeter galaxy at z=2.04. This new source has a similar SED from optical-mid/IR to submm/radio, but significantly higher fluxes, than the well-known lensed SMG SMMJ 2135, the Cosmic Eyelash (z=2.3). It was identified as a result of our full-sky correlation of the Planck compact source catalogue with WISE. Rest-frame UV spectroscopy of this lensed galaxy obtained with the 10.4m GTC shows the typical spectrum of a starburst galaxy at z=2.04. NOEMA DDT observations confirmed unambigiously its SMG-nature via a low-resolution CO(3-2) detection at very high significance, I_CO(3-2)=52.2+-0.9 Jy km/s - factor 4 brighter than the Cosmic Eyelash - resulting in the brightest CO detection ever of an SMG! The morpohology and size of the molecuar gas reservoir is completely unclear. Its unseen apparent CO brightness offers the opportunity to get new insights in the star-formation processes of galaxies at the peak of the cosmic star-formation density and establish the Cosmic Eyebrow as new reference source at z=2 for galaxy evolution. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-03-03T00:00:00.000 |
| 848 | 2022.1.01216.S | 22 | Dust traps in LkCa 15? | Dust trap by pressure bumps is the most promising scenario to avoid the fast radial migration of dust toward the central star. Observational evidences of dust traps have been found around class II disks, however these signatures have been less studied around transition disk, which are expected to effectively trap dust grains in the rings out of their inner cavity. In this proposal we plan to study the band 3 dust continuum emission of the transition disk around LkCa15 at an angular resolution of 55 mas, similar to archive data at higher frequencies. The proposed observation is fundamental to constrain the disk dust properties such as grain size, dust density, and temperature, because it is expected to trace optically thin emission, necessary to correctly infer the opacity spectral index. We expect to find evidence of very high dust grains (> some cm) around the brigth rings of LkCa15 if the dust trap mechanism is effective, and possibly very small grains (< 100 microns) in the gaps and the inner cavity of the disk. The goals that we plan to reach will help us to best understand if transition disk are a good scenario for dust growth and possibly the formation of pebbles. | Disks around low-mass stars | Disks and planet formation | 2024-02-23T22:57:08.000 |
| 849 | 2015.1.01520.S | 28 | Star formation and gas mixing in a multi-phase tail of the nearest jellyfish galaxy | Based on our recent discovery of abundant molecular gas in the tail of the ram pressure stripped galaxy ESO137-001, we propose to map CO(2-1) emission in the whole spectacular double-structure X-ray and star-forming tail with ALMA. ESO137-001 is the best known example of ram pressure stripping in action, where star formation in the disk is quenched but new stars form in the tail. The proposed observations will bring unprecedented understanding on how multiphase ISM responds to strong ram pressure and how it mixes with the surrounding hot intra-cluster medium. We will examine the efficiency of star formation in the extreme environment and from complementary CO(3-2) pointings we will learn about physical conditions in the tail. From comparison with existing observations with Chandra, HST and VLT/MUSE we will search for correlation of gas phases. In combination with gas kinematics and dynamical modeling we will study origin of molecular gas in ram pressure stripped gas tails. Until now, molecular gas has not been mapped in the tail of any ram pressure stripped galaxy. | Spiral galaxies, Galaxy groups and clusters | Local Universe | 2017-05-11T21:23:28.000 |
| 850 | 2023.1.00177.S | 10 | High-resolution Mapping of Cold Molecular Gas in the Turbulent IGM of Stephan's Quintet | Stephans Quintet contains a highly turbulent multi-phase IGM, partly caused by a giant shock wave driven into preexisting gas by a high-speed intruder galaxy. JWST/MIRI observations, and a previous limited ALMA study, have revealed dramatic filaments of warm post-shocked gas mixed with cold molecular clumps, all of which is embedded in million-degree gas detected by Chandra. We propose to fully map the cold molecular gas in CO (2-1) over the entire inner Stephans Quintet at the same spatial resolution as MIRI/JWST to allow us to build a comprehensive picture of the interaction and possible mixing of gas phases as kinetic energy is dissipated behind the fast shock. This includes exploring, a) whether cold clouds shattered by the flow of hot gas behind the shock, can explain the existence of so much warm gas in the group, b) where and under what molecular conditions, stars can form from the turbulent gas, and c) determine whether the mysterious spider-leg filaments seen by JWST surrounding NGC 7319, are somehow kinematically associated with an known AGN outflow. When combined with existing spectacular JWST observations the ALMA observations will be a great Legacy value. | Merging and interacting galaxies, Galaxy groups and clusters | Galaxy evolution | 2025-10-18T15:56:55.000 |
| 851 | 2018.1.00986.S | 88 | MAGNUM FEAR: mind the gap | We propose ACA + TP observations of CO(2-1) of four nearby active galaxies for which we already obtained 12m observations in semi-extended configuration in Cycle 4. Although extended (>30), diffused ionised outflows have been detected through optical nebular line observations with MUSE, clear evidences of outflowing molecular gas are, at best, marginal at large scales and mainly restricted to the nuclear regions. The proposed observations will allow us to definitely test whether cold molecular outflows are mostly diffused and extended on scales of several kpc or simply absent, providing important constraints on the origin and formation of cold molecular outflows. A complete coverage of the uv plane by combining the proposed ACA + TP observations with the current 12m datasets will allow us to assess whether the lack of extended CO emission is associated with the instrumental response or not. We will then be able to fully investigate the morphology and kinematics of the molecular outflows in these galaxies and compare their properties with those of the fast ionised gas. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-11-12T21:51:36.000 |
| 852 | 2022.1.01525.S | 0 | Ice-cold gas in a frying cloud? The temperature of the N2H+ emitting dense gas near the NGC3603 starburst cluster | Feedback from massive stars on dense, star forming gas may significantly affect the resulting stellar population. Higher temperatures may allow for more massive cores to form before they proceed to collapse. As part of a larger effort to search for dense gas temperature variations due to feedback and any resulting differences in fragmentation we here propose to measure the temperature of an allegedly very cold gas component traced by APEX N2H+ observations in several dense clumps nearby the NGC3603 galactic young starburst cluster. H2CO measurements indicate temperatures as high as 50K for the clumps, too warm for N2H+ to survive. The detection of N2H+ in these seemingly warm cores may imply that there is an even colder component, shielded from the feedback, The proposed N2H+ temperature measurements will show whether the N2H+ emission arises in warm, dense gas heated by the cluster (as has been found in Orion by Teng & Hirano 2020), or whether indeed COLD dense gas may still exist in clumps subject to strong external heating. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-11-23T16:15:02.000 |
| 853 | 2018.1.00557.S | 88 | An Astrometric Search for Planets Orbiting in the Alpha Centauri System | We propose a pilot study consisting of a series of high signal-to-noise (SNR) observations of the nearby stellar binary alpha Cen A and B to make precise measurements of their relative orbit. In addition to probing the limits of ALMA's differential astrometric precision, these measurements will improve our knowledge of the orbit of the alpha Cen AB system by factors of two to five in just a few years and will form the start of a search for exoplanets in this system. | Exo-planets | Disks and planet formation | 2020-12-11T20:14:44.000 |
| 854 | 2017.1.01003.S | 132 | Recovering Extended Structures in Merger Remnants | Contrary to the classical scenario of galaxy merger in which an elliptical galaxy forms due to a major merger, recent studies argued that some fraction of the merger would reemerge as a disk galaxy by forming an extended gaseous disk. In order to check this scenario, we conducted a CO (1-0) survey on local merger remnants with the Cycle 0 ALMA 12m-array and found a high occurrence rate of molecular gas disks with various sizes. However, the ALMA data were taken using the 12m-array alone and they were clearly suffering from the missing flux problem, up to 57% in the worst case. Correctly quantifying the true size of the molecular disk and assessing its relation to the stellar size is the key to unambiguously define the type of galaxy the merger will evolve into. We thus propose follow-up CO (1-0) observations with ACA towards 14 merger remnants to accurately measure the extent and amount of molecular gas, by combining new ACA data with the Cycle 0 12m-array data. This study will allow us to accurately evaluate the frequency of the occurrence of extended gas disks in post-mergers, and offer stronger support to the scenario that merging events are the crossroads of galaxy evolution. | Merging and interacting galaxies | Galaxy evolution | 2019-12-27T00:00:00.000 |
| 855 | 2023.1.00193.S | 0 | [CII] 158um emission line and dust observation of the most distant known overdensity of galaxies at z=7.88 | Galaxy over-density in the epoch of reionization would be one of the most important objects in the extragalactic study as they may enhance early massive galaxy growth. Further, previous studies suggest that galaxy over-density may create bubbles of ionized hydrogen and largely contribute to cosmic reionization. Fully characterizing the physical conditions of galaxy over-densities at high redshift will allow us to study how massive galaxies formed as well as how they contribute to cosmic reionization. During the JWST Cycle-1, observations spectroscopically confirmed the highest-redshift, densest galaxy over-density known to date at z=7.88 that has five galaxies in a 3"x3" (~11kpc x 11kpc) region. Here, we propose to exploit this unique opportunity to build a strong synergy with one of the richest JWST data: (i) to obtain ISM properties by detecting [CII] 158um lines from at least three member galaxies ; (ii) to perform deep searches of dust-obscured star formation. In particular, confirmation of dust would suggest enhanced dust enrichment histories in over-dense environments and would require revisions of our view about how over-densities contribute to forming ionized bubbles. | Lyman Break Galaxies (LBG), Galaxy Clusters | Galaxy evolution | 2025-06-18T16:03:38.000 |
| 856 | 2018.1.00888.S | 32 | Constraining the mass of the fastest molecular outflow in the local universe | Feedback from active galactic nuclei (AGN) and/or nuclear starbursts in the form of molecular outflows is frequently invoked in galaxy evolution to explain the observed black-hole - bulge property correlations, but despite many observations of massive molecular outflows, their energetics are still poorly constrained. The unknown chemistry and column density of the outflowing molecular gas dominate the uncertainty in the outflow mass (via the CO luminosity to H2 conversion factor), and thus the energetics and origin of the outflow. We propose simultaneous high-resolution (0.2'') observations of 12CO(3-2) and its optically thin isotopologues in IRAS 20100-4156, an IR-luminous galaxy hosting the most energetic molecular outflow nearby, as a way to obtain the outflow column density, trace the entirety of the outflowing gas, and thus obtain its true mass and energetics. Such observations are crucial to test theoretical models for how outflow energy/momenta couple to the AGN/starburst luminosity. Our proposed observations also offer the opportunity to study the nucleosynthesis history and test the role of the nuclear starburst in launching the observed outflow. | Outflows, jets, feedback | Active galaxies | 2020-06-19T15:30:17.000 |
| 857 | 2023.1.01564.S | 0 | Connecting the molecular gas properties with the kinematic status of protocluster galaxies at z=1.5 | The cosmic noon marks not only a key transitional epoch for galaxies, but a period when protoclusters experience major albeit rapid changes, setting the (pre-)conditions for environmental effects. Recent works reported that galaxies in young assembling protoclusters display higher gas fractions than the coeval field. The reason for this unexpected finding is still unknown, with enhanced cold gas accretion or frequent galaxy-galaxy interactions as the two most likely scenarios. However, the small size and heterogeneous nature of these studies prevent us from obtaining an unambiguous view of the dominating mass growth driver in early dense environments. For these reasons, we aim at connecting the molecular gas properties with the degree of kinematic support (a proxy for galaxy interactions) of the hosts in a young clumpy protocluster at z=1.5. We propose new ALMA observations of CO(1-0) for galaxies with available and robust H-alpha velocity fields from KMOS/VLT. By combining the ionized gas kinematics with the new cold gas reservoir constraints we will disentangle these two scenarios and shed light into the accelerated evolution of massive star-forming galaxies in protoclusters. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2025-08-20T11:47:10.000 |
| 858 | 2019.1.00732.S | 2 | Unique Constraints on the Origin of Carbon in Terrestrial Worlds | We propose to search for evidence of carbon grain destruction in the inner regions of the young protostar NGC 1333 IRAS 2A. The motivation is based on the fact that half of the C in the ISM is found in refractory C-rich grains. These grains are seen in comets (Halley, 67P), but the Earth has four orders of magnitude less C than carried by interstellar carbon grains. Primitive meteorites, which otherwise directly trace solar abundances, are also missing this carbon. Carbon carried by ISM grains must have been in the gas within the inner solar system prior to the main phase of planetary assembly. We have isolated ~350~K as the sublimation temperature of interstellar refractory carbon and propose to search for evidence of carbon grain destruction in IRAS 2A. Our observations will be obtained with 0.07" resolution (16au) to resolve gas with T > 350 K which extends to 40au in diameter. We will observe species (H13CN, and hydrocarbons) that are predicted to be signatures of this effect and search for chemical transitions in very hot gas. If such a mechanism is isolated, this would have profound implications for the origin of carbon in all terrestrial worlds. | Low-mass star formation, Astrochemistry | ISM and star formation | 2022-10-26T22:22:02.000 |
| 859 | 2024.1.00315.S | 0 | ALMA Observations of Cepheid Envelopes: Refining the Period-Luminosity Relation in the JWST Era | Cepheid variables provide a crucial step in the cosmic distance ladder from the Milky Way Galaxy to the distant Universe. The James Webb Space Telescope is now observing extragalactic Cepheids to refine the distance scale. However, the circumstellar envelopes (CSEs) of Cepheids could affect the Period-Luminosity (PL) relation and potentially bias the distance scale. We propose to observe the emission of the gaseous CSE of 6 bright Cepheids at 211 and 275 GHz with the 12 m ALMA array. The objective is first to provide a physical model of the gaseous CSE. This will be used to apply synthetic filters from the NIRCam/JWST to quantify the CSE impact on the PL relation. Our final objective is to provide a grid of photometric corrections in the JWST bands to correct for the CSE effect on PL relation used in the extragalactic distance scale. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2025-10-11T13:29:08.000 |
| 860 | 2018.1.00339.S | 126 | Structure and dynamics in Lupus starless cores | The structure and dynamics of starless cores is key to determining their current status and ultimate fate. We propose an ACA-only project to image at 4arcsec resolution a sample of the brightest starless cores found in Lupus. This project is unique in that we already have ALMA 12m data which shows no compact young stellar object is present; yet the single-dish fluxes are relatively high. With the intermediate resolution of the Morita ACA, we will image where this 'missing' flux lies, deriving the density structure of these cores on a few 100 to few 1000au scale. Simultaneously, we will measure the gas dynamics on this size scale, looking at infall and turbulent motions and multiple structure in the cloud cores. Taken together we will compare with simple smooth Bonner-Ebert spheres, and determine whether there is evidence of dynamical and structural evolution towards the first stages of a YSO. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-07-09T12:55:54.000 |
| 861 | 2017.1.01616.S | 90 | Superluminous Supernova Host galaxies in CO - Assessing Molecular Gas in Nascent Starbursts | Super-luminous supernovae (SLSNe) are mysterious explosions that challenge our understanding of stellar evolution. During the last years, our team has carried out a systematic survey of their host galaxies. We have discovered important differences between the environments of SLSNe of different types, and we revealed that H-poor SLSNe show a preference for young starburst dwarfs, similar to extreme emission-line galaxies. In contrast to other starburst samples, SLSNe pinpoint galaxies just a few million years after the beginning of the starburst. We propose an explorational programme to recover CO emission of 3 H-poor and 3 H-rich SLSN host galaxies to assess their molecular content. We will constrain the physical properties of the molecular gas and combine these measurements with our UV-to-near-IR photometry and spectroscopy to put the molecular gas in context of the stellar component. These findings will provide a new perspective on the conditions of the molecular gas during an elusive and extreme phase in galaxy evolution that are more akin to that observed in high-z starbursts. The observations will be a pivot for future observations at higher frequencies and of other objects. | Starburst galaxies | Active galaxies | 2019-03-28T17:44:23.000 |
| 862 | 2021.2.00177.S | 460 | 'Shaping' the outflows of massive protostars | We propose ACA Band 6 observations to map the molecular outflows from 47 massive protostars. The targets are chosen from the SOFIA Massive Star Formation (SOMA) project. The sample include sources with different evolutionary stages and environmental conditions, such as MIR sources in IRDCs, Hyper-compact, Ultra-compact HII regions, and Clustered regions. With a single pointing on each source, ALMA can complete this survey with relatively high resolution and sensitivity within 8 hours. With the proposed observation, we aim to 1) map the slower swept-up outflow on the core scale, estimate their masses and opening angle, and combining with properties of the cores and protostars constrained in IR observations and radiative transfer modeling, to estimate the strength of outflow feedback and investigate the dependence of outflow properties on the evolutionary stage and environments of massive star formation. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2023-06-15T09:48:35.000 |
| 863 | 2015.1.00894.S | 30 | First spatially-resolved imaging of a massively star-forming, cooling-flow galaxy cluster core using the Sunyaev-Zel'dovich effect | We propose to resolve, for the first time, the core of a massively star-forming, cooling-flow galaxy cluster using the thermal Sunyaev-Zel'dovich effect (SZE). Our target, SPT-CL J2344-4243 at z=0.596 (the Phoenix cluster), is so far the only galaxy cluster that hosts rapid gas cooling and star bursts in the central core. Not only its X-ray luminosity but also its peak SZE intensity is expected to be the largest among all galaxy clusters known to date. Only ALMA can resolve the compact core of this cluster and explore its dynamical state via the SZE. Our observation will open new directions in exploitation of the physics of galaxy clusters and serve as a pathfinder for more comprehensive SZE studies to be done with full ALMA. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2017-09-08T13:06:38.000 |
| 864 | 2023.1.00434.S | 0 | A Survey of Radio-Loud Quasars Host Galaxies at Cosmic Dawn | Radio-jets are thought to play a key role in shaping the host galaxy/black hole co-evolution in AGN, via the so called radio-mode feedback. However, little is currently known about this process at the highest redshift, where feedback is invoked to be crucial in early massive galaxy evolution, mainly due to the limited number of radio-loud QSOs previously known at z>5. In the last couple of years, such sample has more than doubled, amounting now to >60 sources. Here, we aim to detect the [CII] emission line and underlying far-infrared continuum in the host galaxies of 27 radio-loud QSOs at z>5. We will study their physical properties, i.e. gas/dust content, star formation rates, [CII] morphology, and compare them with those of the available large radio-quiet QSOs sample, to highlight any feedback role from the jets. Furthermore, we will assess whether high-z radio-loud QSOs are ubiquitously found in the first protoclusters, as suggested by both theoretical and observational studies. This systematic survey of the dust and [CII] emission in radio-loud QSOs at z>5 will enable the first new statistical investigation of the role of radio jets in galaxy evolution at Cosmic Dawn. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-01-09T23:42:11.000 |
| 865 | 2012.1.00307.S | 15 | Resolved, direct imaging of the obscured star forming regions in SMGs | Submillimeter-luminous galaxies (SMGs) are extremophiles in the spectrum of high-z star forming galaxies, with star formation rates higher than almost all other objects in the known Universe. Yet despite their enormous luminosities, a number of factors conspire (faintness/dust-obscuration in the optical, limiting resolution of longer wavelength telescopes) which leave few clues as to the actual distribution of the star formation, or what is triggering their massive bursts. With ALMA in Cycle 1, the situation is fundamentally changed. The resolution/sensitivity is now such that one can resolve the obscured star forming regions in SMGs in the rest-frame far-infrared (FIR) - the most direct tracer of star formation in dusty starburst galaxies - at resolutions comparable to what Herschel has achieved in nearby galaxies (~1 kpc). To this end, we propose 870 micron (Band 7) imaging of a statistically-significant sample of 15 SMGs employing ALMA's most extended configuration. The proposed targets were carefully selected from our ALMA Cycle 0 compact array (1.4") survey of >100 SMGs, the largest, most homogenous, and highest-sensitivity sample of interferometrically observed SMGs to date, and they all have deep existing or forthcoming HST/WFC3 imaging. We will spatially-resolve the obscured star forming regions in these ALMA-confirmed SMGs on scales down to 0.16" (equivalent to ~1.3 kpc at the median redshift of z~2.5), directly addressing two of the biggest observational unknowns regarding the SMG population: (1) How is the star formation distributed? and (2) What are the star formation rate densities of the starbursts? This proposal will provide the observational foundation necessary to discriminate between the various models which have been put forward to explain the extreme star formation rates of SMGs, including major mergers, isolated disks undergoing secular bursts/cosmological gas accretion, or some combination thereof. Requiring just 4 hours, this project is possible for the first time with ALMA in Cycle 1, and it will produce significant scientific results in an area that, until now, existed firmly in the realm of theory. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-10-13T20:36:48.000 |
| 866 | 2022.1.00817.S | 20 | Further high resolution observations of two binaries AGB stars: R Aqr and omi Cet | Binary stars including an AGB star hold the clues for understanding important phenomena in stellar evolution, such as common envelope events, the formation of SN Ia, and the origin of aspherical pPNe/PNe. Hydrodynamical codes, simulating the companion's influence on the primary's mass loss, are mature. However, we still lack information on the orbital parameters of systems where these hydro-models can be thoughtfully tested. The two best cases where this can be pursued are R Aqr, a close symbiotic system, and omi Cet, the closest resolved binary AGB star. We propose new 12m C-10 observations in bands 6 and 7 to obtain the relative positions of the two stars for epoch ~2023.7 in R Aqr and omi Cet systems. We plan to self-calibrate the data with SiO masers to obtain optimum image fidelity in the continuum. In the case of R Aqr, the observation of RRLs and HCO+ will help in locating the secondary and provide information on its velocity. This will be crucial for the determination of the orbital parameters, but also the masses of the stars and the distance to the systems. In the case of omi Cet, the new data will help in testing the presence of a third star in the system. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-09-13T14:55:10.000 |
| 867 | 2022.1.01572.S | 70 | Calibrating [CI] as a molecular gas tracer in high-z star-forming galaxies. | Charting the evolution of the cold gas content of high-z galaxies is paramount to our understanding of galaxy evolution. There have been many efforts in the last decade to find and calibrate molecular gas mass tracers alternative to the hard-to-observe CO(10) at high-z. The [CI] (1-0) and (2-1) lines are a potentially promising alternative, since they have a similar critical density to CO(1-0) and their luminosity traces gas mass well in local galaxies. However, this correlation remains poorly probed at high-z due to the low number of sources detected simultaneously in CO(1-0) and [CI](1-0)+(2-1) lines. This is set to change with recent JVLA observations targeting CO(1-0) in an unprecedented sample of 30 unlensed sources at z=25, 25 of which also have [CI](10) observations from previous ALMA cycles. We request 15h to observe [CI](2-1) and CO(7-6) in 19 sources from this sample, which will allow us to obtain a unique calibration of molecular gas mass and luminosity-mass conversion factors for [CI] in high-z SMGs. | Starbursts, star formation | Active galaxies | 2025-01-17T13:36:32.000 |
| 868 | 2015.1.01355.S | 24 | Cold gas in the most distant cluster galaxies: completing the ALMA picture of CL J1449+0856 at z=2 | In ALMA Cycle 1 we proposed to observe 850um continuum and CO[3-2] line emission in CLJ1449+0856 at z=2, the most distant spectroscopically confirmed X-ray detected cluster known thus far. 850um data were delivered in December 2014, reaching 0.4mJy (5sigma), thus SFR>40Msun/yr and M_stars >2e+10Msun at z=2. We detect six sources at F_850>0.5mJy over a 0.12 sq.arcmin area, a 10x overdensity with respect to blank field expectations. The second and central part of our Cycle 1 program, probing molecular gas in these sources, has not been carried out yet, and will be terminated at the end of Cycle 2. To complete our project, and taking advantage of our improved knowledge on CLJ1449+0856 and on CO SLEDs since Cycle 1, we propose to observe the CO[4-3] line at z=2 in two band 4 pointings, to unambiguously identify 850um sources belonging to the cluster, and measure SFRs and sSFRs, gas masses, gas fractions, star formation efficiencies, and depletion times of SF cluster galaxies. By comparison with field galaxies at similar mass and redshift, this study will provide a first picture of environmental effects on obscured star formation and gas reservoirs in early cluster environments. | Galaxy Clusters | Cosmology | 2017-08-05T17:44:35.000 |
| 869 | 2015.1.00467.S | 28 | Tracing the physical conditions of a jet-driven molecular outflow | Our Cycle 1 CO(2-1) ALMA observations of the massive AGN-driven outflow of molecular gas in the Seyfert 2 galaxy IC5063 have revealed one of the most detailed kinematical views of the impact of an AGN jet ploughing through its surrounding ISM. As a result of our modelling of the kinematics, we have been able to identify several zones in the gas distribution, each corresponding to a different phase in the jet-ISM interaction. Here we propose to use several tracers (12CO 3-2 and 1-0 and 13CO 3-2) to characterise the physical conditions of these components. The proposed observations will allow to derive key parameters (density, temperature, excitation, heating) and will provide new insights in the physics of a jet-ISM interaction. Given the high level of detail observable in IC5053, these data will provide a template for studies of other objects. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-06-23T15:22:02.000 |
| 870 | 2016.1.00329.S | 63 | Testing the cold ISM removal mechanism in passive galaxies | One of the key issues lacking in our understanding of cosmic dust is how galaxies are getting rid of it. It is tricky to track dust removal, because usually dust is constantly replenished by consecutive generations of stars. In order to overcome this we selected dusty passive galaxies, which still have detectable dust content, but exhibit a low current supernova dust production (and destruction) rate due to the long time since the last major star formation event. Therefore any decline of dust content as a function of their age can be attributed to dust removal. We found that their dust and gas content declines rapidly at ages > 2 Gyr, allowing us to constrain the timescale of the ISM removal in these galaxies. However, an important aspect of the nature of this mechanism needs to be tested: is the removal of the ISM due to outflows or do we detect the effect of heating of gas, which destroys dust and molecular gas? Distinguishing this would allow us to understand how passive galaxies are getting rid of the ISM, and we plan to achieve this via high-resolution CO(1-0) observations to look for signatures of outflows. | Outflows, jets, feedback, Early-type galaxies | Active galaxies | 2018-02-11T09:09:49.000 |
| 871 | 2018.1.01538.S | 78 | Testing the gravitationally stability toward the innermost accretion system in high mass star-formation | We propose the follow-up observations towards the nearly face-on accretion system around a high mass young stellar object G353.273+0.641. We have successfully obtained the first bird's-eye view of the innermost accretion system by 50 mas resolution at band 4. We detected highly inhomogeneous and clumpy surface density structures, suggesting the gravitationally unstable nature of the accretion disk. In this proposal, we will test a gravitational stability of the system by multi-band follow-up observations at band 6 and 7. We will determine (1) 2D distribution of the spectral index, (2) radial temperature profile, (3) any local variation of dust opacity index. Combining these information, we will estimate a surface density distribution and Toomre Q parameters by pixel-by-pixel. This gives the first quantitative analysis on the highly self-gravitating disk in high mass star-formation. We also observe several CH3OH lines at band 7, in order to study a outer molecular envelope that showed infalling motion with angular momentum conservation in cycle 4 data. We will determine better kinematic parameters including an infall rate onto the disk by using higher spectral-resolution data. | High-mass star formation | ISM and star formation | 2020-11-14T00:00:00.000 |
| 872 | 2019.1.01206.S | 10 | Unveiling the nature of an unusually large gaseous transit in a debris disk | Debris disks can be seen as the left-overs of the star formation process and the possible nurseries of rocky planets. They were commonly understood as gas depleted but recent gas detections, including our own, challenge this concept. Second generation gas can be produced by collisions of icy bodies or star grazing exocomets and its effect on the dust particles may affect planet formation. We have detected an unusually large CaII absorption in the debris disk HD37306 using high-resolution spectra. We interpret this event as an exocometary transit. These gas absorptions can only be observed if the outgassing event is crossing the line of sight of the star. This method severily limits our chances of further detections and only allows us to partially trace the gas in the system, unlike ALMA observations in emission. As CO is prone to photo-dissociate and thus has a relatively short lifetime, by detecting CO we would confirm that outgassing processes are currently occurring in the disk. We aim to detect CO in Band 8 to confirm the nature of the gas, estimate the gas content and, possibly, be able to resolve this faint debris disk for the first time to directly constrain its orientation. | Debris disks | Disks and planet formation | 2021-07-03T22:30:05.000 |
| 873 | 2021.1.00668.S | 66 | The golden ratio: OIII-to-CII ratio census in SFR-selected sample | We propose to observe the OIII emission line of thirteen galaxies and eight nearby quasars (21 in total) at z > 6 using ALMA. These galaxies are detected in [CII] 158um, and are thus -- unlike any other z > 4 sample -- SFR-selected. This selection makes this sample ideal for the proposed observations of [OIII]. These observations will probe the [OIII] to [CII] luminosity ratio in a SFR-selected sample beyond z > 6, and double the number of sources with line detections of both [CII] and [OIII]. The [OIII] line traces the electron density, metallicity and intensity of the ionizing radiation field, and combined with the selection criterion, this will allow us to test all current hypotheses for this high [OIII]/[CII] ratio. Moreover, we will detect the dust continuum (only four galaxies are detected in continuum at 158um), which can be used for more-accurate obscured SFR and dust mass estimates, and finally, our sensitive observations will reveal the [OIII] emission and above-mentioned properties from the eight nearby quasars at high fidelity. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2023-06-14T06:04:51.000 |
| 874 | 2013.1.01380.S | 3 | Testing magnetic braking in the Class 0 B335 | The absence of detected rotational motions in B335, as well as our recent SMA detection of polarized dust continuum emission suggest an efficient magnetic braking at work in this very young protostar. As a first step towards characterizing magnetic braking at work in protostellar envelopes and assess its effect on re-distributing the envelope angular momentum outwards, we propose to carry out a detailed continuum polarization map of B335 with ALMA in Band 6. The resulting ALMA polarization map will also have enough signal-to-noise to be compared in details with outcomes of MHD simulations. Thanks to detailed information on both the magnetic fields spatial distribution and the envelope kinematics probed by SMA high angular resolution observations, we will be able to put strong constraints on the role of magnetic braking to drive angular momentum transport, and regulate the accretion rate, disk formation in B335. | Low-mass star formation | ISM and star formation | 2017-11-21T00:00:00.000 |
| 875 | 2022.1.01237.S | 9 | Are fibres present in the giant molecular filament G214.5-1.8 | The dense ISM is predominately structured into filaments which act as intermediate steps in the star formation process, connecting molecular cloud scales to the core scale. However, there remains numerous uncertainties in how massive filaments fragment into cores and remain long-lived. One theory in the literature is that such massive filaments are actually composed of numerous smaller, more stable filaments called fibres, the densest of which harbour cores and form stars. This scenario would imply that fibres are universal structures which allows one to unify low-mass star formation and high-mass star formation by connecting a filament's line-mass to the surface density of fibres and thus star formation surface density. This prediction requires thorough testing across line-mass scales. This project proposes to do just that by observing the giant molecular filament G214.5 using N2H+(1-0). Current work shows G214.5 to be highly narrow, sub-virial, quiescent and has an unexplored line mass (~280 Msun/pc), making it an ideal target to test the universality of fibres. It is only with ALMA's high-angular resolution that this can be achieved. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-10-25T13:48:54.000 |
| 876 | 2011.0.00206.S | 0 | Dust continum and [C II] line emission from quasar host galaxies at z~6 | Huge amounts of far-infrared (FIR)-emitting warm dust and molecular gas have been discovered in the host galaxies of ~30% of the quasars at z~6, indicating the presence of massive star formation coeval with rapid supermassive black hole (SMBH) accretion close to the end of cosmic reionization. We propose for ALMA Band 6/7 observations of the dust continuum and the [C II] 158 micron fine structure line emission toward five FIR and CO luminous quasars at z~6. The FIR dust continuum and [C II] line are the strongest probes of star forming activity in these quasar-starburst systems at the highest redshift. The cycle 0 phase of ALMA in the extended configuration has the required sensitivity, frequency coverage, and spatial resolution (~0''.6 or 3.5 kpc at z~6) to allow a systematic study of these signatures of star formation in a large sample of FIR and CO luminous z~6 quasars. Our goals are to investigate the general properties (star formation rate, average surface density, and size) of the nuclear star formation traced by the dust continuum and [C II] line emission in these earliest quasar host galaxies and study the distributions and physical properties of the dust and atomic gas components. The sub-arcsec spatial resolution will also allow us to search for possible companion starburst sources close to the optical quasar. These are the keys to probe the coeval formation of the first SMBH and massive galaxies at the earliest epoch. | High-z Active Galactic Nuclei (AGN), Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2013-06-25T16:06:00.000 |
| 877 | 2017.1.00049.S | 38 | Supernova fall-back disks around neutron stars | Supernova fall-back disks have been suggested to play in important role in the formation of different classes of neutron stars. They could, for example, the irregular pulsations of rotating radio transients. They have also been suggested as the sites for in sity planet formation after the very first exoplanets where surprisingly detected around the millisecond pulsar B1257+12. An in situ formation would require a dust disk in which the dust particles coagulate to large grains and planetesimals, eventually forming rocky planets. The cool SN fall-back disks with large dust grains are expected to radiate predominantly in the (sub-)millimetre regime. However, various searches for such disks have so far not provided any results. While impossible with other ground-based instruments, ALMA will finally convincingly prove or rule out the existence of a cool dust disk around nearby pulsars. We have chosen the best candidate pulsars to host a disk. These include the planet pulsar B1257+12, the solitary pulsar B0656+14 which has a peculiar excess in the visual bands, and the young nearby Vela and Geminga pulsars. | Supernovae (SN) ejecta, Pulsars and neutron stars | Stars and stellar evolution | 2019-01-31T23:02:30.000 |
| 878 | 2017.1.01053.S | 708 | SMORES: Shocked Molecular Outflows across a Range of Environments Survey | Prior observations of molecular outflows have revealed that not only do these harsh, energetic environments contain a surprising array of complex molecules, but they also show highly-localized spatio-chemical differentiation. Because the velocities of these jets are relatively well-constrained, it is possible to associate distance within the outflow with temporal evolution of chemistry. As well, the collimated nature of the outflows provides a relatively compact region in which comparisons can be made between outflow, shocked walls, and background ambient gas in a variety of density and temperature conditions as the chemistry evolves. Here, we propose to conduct a broad, unbiased Band 7 spectral line survey with the ACA of seven southern outflows of widely-varying ages, velocities, and chemical conditions to elucidate the underlying links between physical conditions, outflow properties, and chemical evolution in these important pre-stellar environment. | Outflows, jets and ionized winds, Astrochemistry | ISM and star formation | 2019-03-06T20:53:56.000 |
| 879 | 2018.1.01222.S | 33 | Measuring the Mean Molecular Weight of Gas in Debris Disks | Understanding the molecular makeup of the gas in debris disks is one way of determining whether its origin is primordial (in which case it should be dominated by H2) or second-generation like the dust (in which case the H2 content should be very low), both of which have important implications for our understanding of the origin and evolution of planetary systems. So far, CO is the only molecule that has been detected in debris disks, despite a few sensitive searches for other tracers. Here we propose to determine the mean molecular weight of the gas in the debris disk around 49 Ceti, thereby determining its origin, using only measurements of CO molecular emission. Our method relies on two separate measurements that will break the degeneracy between the currently unknown H2 number density and kinetic temperature: we must (1) spatially resolve the vertical structure of the molecular gas disk, and (2) measure the excitation temperature via an optically thin line ratio. By combining these measurements, we can determine the mean molecular weight to a precision of 25%, thereby distinguishing a primarily H2 composition from a more cometary mix of gases. | Debris disks | Disks and planet formation | 2020-09-21T18:50:11.000 |
| 880 | 2023.1.01265.S | 0 | Deep [OI] observation toward a luminous quasar at z = 6: seek for dense outflows missed by [CII] | Active Galactic Nucleus (AGN)-driven massive outflows have been claimed to be a key physical process to quench star formation and to drive the co-evolution of black holes and galaxies. However, previous ALMA observations did not find clear evidence of [CII] outflows in z > 6 luminous quasars, which should be the most vigorous site of AGN feedback. Considering the cases of nearby AGNs, here we speculate that the non-detection of [CII] outflows would be due to high gas density of the outflows. To test this possibility, we propose deep (55 uJy/beam) [OI] 145um line observations (critical density is ~30 times higher than [CII]) toward the z=6 luminous quasar J2054-0005. There is no evidence of [CII] outflow in this quasar but we do find a fast molecular outflow in OH absorption. Hence this quasar is an ideal laboratory to test our hypothesis. We will seek for dense neutral outflows in [OI]. By also using [CII] data, we can constrain the ISM properties by performing PDR modeling. With the proposed resolution, we will constrain the size of the outflow, and key physical properties (outflow rate, kinetic energy, etc), which are critical to understand the nature of the AGN feedback. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2025-05-15T07:04:37.000 |
| 881 | 2018.1.00794.S | 19 | A high-mass young star mimicking a red-giant? | Stellar structure has long predicted that the seed of a forming high-mass star would be a luminous lower mass object in a bloated state. Testing this hypothesis is extremely challenging, because such seeds would be highly embedded. If the outflow inclination angle is favourable to the observer, the photospheric light flashes through the cavity. We have discovered one such object, an enigmatic near-infrared bright variable star (K=2.9mag, J-K=2.4) with H-alpha emission and a spectral energy distribution of a massive YSO. It is located at the peak of a massive star-forming clump (traced by ATLASGAL), and a 6.7GHz methanol maser (indicating massive outflow) is located 6" from the star. New echelle zYJHK spectra of this star surprisingly represents a MIII type red-giant. New VLA continuum data at 0.5" resolution do not show any free-free emission. We want to search for outflow and/or accretion signatures around this star using ALMA, finding which will lead to the discovery of the first bloated massive protostar. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2020-08-07T22:04:37.000 |
| 882 | 2016.1.00504.S | 52 | Molecular shocks in the nucelar region of NGC 4038 (Antennae galaxies) | Numerical simulations of galaxy mergers have predicted the ubiquitous presence of gas inflows into the nuclear region. The inflowing gas could collide with gas component associated with the nuclear region, causing molecular shocks, and the gas density increases rapidly. From our previous observations with ALMA, we find a signature of gas inflow and molecular shocks in the nuclear region of NGC 4038. We suggest that the molecular shocks may be caused by collisions between the inflowing gas and the central massive molecular complex. The main purpose of this proposal is to quantify the density of molecular gas in the shock region. We thus propose to image the nuclear region of NGC 4038 in the three dense/shocked gas at 50 pc scale. We will compare the density of molecular gas in the shock regions with the other regions to confirm, observationally, the scenario that the density of molecular gas increases in the shock region created by merger-induced gas inflows. Furthermore, we found that the distributions of CH3OH and HNCO are slightly different in the nuclear region of NGC 4038. We also aim to investigate the origin of the different distributions of these two shock tracers. | Spiral galaxies | Local Universe | 2018-03-30T14:02:34.000 |
| 883 | 2015.1.00016.S | 13 | A search for extragalactic argonium, ArH+, a probe of the very atomic diffuse interstellar medium | The J = 1 - 0 transitions of 36ArH+ and 38ArH+ near 617.5 and 616.6 GHz were detected in absorption toward the Galactic Center source Sgr B2 with the Herschel Space Observatory. The former was also seen toward several prominent galactic continuum sources. Model calculations suggest that the cation samples in these observations exclusively the very atomic, diffuse ISM with a molecular fraction of about 10-3 or less. We propose to search for ArH+ toward PKS 1830-211 and B 0218+357 at z = 0.89 and 0.68, respectively, in order to gain more insight into the role of this cation as a probe of the very atomic, diffuse ISM and to determine 36Ar/38Ar ratios in the earlier Universe. | Astrochemistry | ISM and star formation | 2017-12-24T03:50:49.000 |
| 884 | 2019.1.01216.S | 153 | ALMA Mapping of the Most Distant Galaxy Proto-Cluster Anchored by A Luminous Quasar at z=6.63 | Simulations predict that luminous high-redshift quasars reside in the most massive halos and are tracers of overdensities, or proto-clusters. However, there has been no previous spectroscopic confirmation of porto-clusters associated with z>6 quasars. We recently discovered a candidate proto-cluster surrounding a z=6.63 quasar, traced by fifteen bright submm galaxies (SMGs) over a region of 4'x6'. With a single ALMA pointing centered on the quasar, we confirmed three galaxies at the quasar redshift by detecting [CII] lines, further suggesting this system is likely to be a proto-cluster. We propose to firmly confirm it as a proto-cluster by detecting [CII] of these SMGs with multiple ALMA pointings. Once confirmed, it will be the most distant proto-cluster yet known, and the first proto-cluster associated with a z>6 quasar. The ALMA observations will also map the star formation, measure the mass of the proto-cluster. In addition, we will perform high resolution [CII] observations and detect CO(7-6) and [CI] lines to measure the gas mass, the gas depletion time, and to constrain the excitation model of quasar host, enabling detailed studies of the assembly of this massive galaxy. | High-z Active Galactic Nuclei (AGN), Galaxy Clusters | Active galaxies | 2022-09-01T18:39:29.000 |
| 885 | 2011.0.00467.S | 0 | Dense Gas and Starburst/AGN Activities in the Late-stage IR-Bright Merger VV114 | Numerical simulations have demonstrated the importance of galaxy collisions and mergers in triggering massive bursts of star formation in the host galaxies. Recent high resolution simulations that include an improved treatment of the multi-phase ISM have shown that star formation not only increases as the galaxies first collide, but it also persists at a higher rate throughout the merger process, peaking at the final coalescence. An observational test of gas response requires mapping both the diffuse and dense gas tracers in merging U/LIRGs at high spatial resolution. Here, we propose Cycle 0 ALMA observations to obtain 0.5-1.6" (200-640 pc) resolution maps of a gas-rich late stage merger VV114 in HCN(4-3), HCO+(4-3), 12CO(3-2), 13CO(3-2), 12CO(1-0) and 13CO(1-0) lines. The relative proximity, -17 deg declination, and the rich array of multi-wavelength (HST/Spitzer/Chandra/VLA) complementary data make VV114 a particularly good target for the Cycle 0 ALMA investigation. By analyzing the new ALMA data with 5 times higher angular resolution and 10 times improved sensitivity over the existing data, we aim to map the distribution and kinematics of dense molecular gas and the dense gas mass fraction and interpret the dense gas properties and their relation to star formation and AGN activities in the context of the merger-induced response of the ISM in the progenitor disks. These new observations will allow us to characterize the gas properties of this galaxy pair that is known to harbor an AGN and have extended starbursts across the galaxy pair, likely evolving to a ULIRG in the future. | Merging and interacting galaxies, Inter-Stellar Medium (ISM)/Molecular clouds | Galaxy evolution | 2013-12-05T01:04:00.000 |
| 886 | 2021.1.01458.V | 0 | Resolving the gamma-ray emission region and the jet collimation profile in TeV blazar Mrk 501 | This is a resubmission of our approved programs in Cycle 5, 6, and 7 as part of the EHT at Band 6. Since the source flux has been slightly below 500 mJy, the observations were not performed. Here we aim to get the project finally observed in Cycle 8 with the newly introduced ALMA passive-phasing from a nearby bright quasar. Extremely relativistic jets emanating from the TeV gamma-ray blazars are one of the presumable candidate sites for the origin of the high energy photons' emitting region. By resolving the compact upstream end of the jet (so-called radio core) in Mrk 501, which is one of the closest and the representative TeV blazars, we will unveil the innermost jet structure and obtain the precise size and flux of the radio core. The core size will be measured with the highest resolution of the EHT operating at 230 GHz, which is comparable to the predicted size of the gamma-ray emitting region. By combining those observations with requested GMVA+ALMA and multi-frequency VLBI & high-energy observations, the origin of the gamma-ray emitting region will be revealed, and the powering source of the jet and its location will be identified. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-09-10T05:44:28.000 |
| 887 | 2021.2.00174.S | 0 | A first determination of HC14N/HC15N on Neptune: filling a nitrogen isotopic ratio gap in the middle of our solar system | We propose to observe Neptune's HC15N(J=4-3) emission line along with HCN(J=4-3) and H13CN(J=4-3 simultaneously for the first determination of 14N/15N isotopic ratio in Neptune's atmosphere to constrain the formation and evolution scenario and/or the origin of the stratospheric volatiles. In our solar system, measured 14N/15N values can be grouped as Sun/Jupiter (~440) and comet (~150) group. Since Neptune is located in the middle of Jupiter and the outer solar system, a new measurement of its nitrogen isotopic ratio value will not only fill the gap in our knowledge on the radial variations of isotopic ratio slope but also to constrain the formation process scenario and/or the origin of the stratospheric volatiles. | Solar system - Planetary atmospheres | Solar system | 2025-05-30T13:59:17.000 |
| 888 | 2013.1.00165.S | 12 | The metamorphoses of Fe and the elusive FeO | The non-detection of FeO in the interstellar medium remains a long standing enigma. Both Fe and O have high cosmic abundances, and FeO has been expected to form in diverse environments such as the atmospheres of M-stars, photon-dominated regions and shocks. Until today, there has been only a single case claiming the detection of FeO. With this proposal we aim to focus efforts for detecting FeO in regions of dense, shocked gas within the envelope of the embedded protostar HH 212. These regions show high concentrations of oxygen-bearing molecules together with hot (T = 1300K) Fe in the gas phase, which represents an ideal environment to ignite the oxidization reactions leading to FeO. The proposed observations will reach 15 times higher sensitivity than previous surveys. Given the favorable conditions for the formation of FeO in the proposed targets and the high sensitivities reached, we are confident that FeO will be firmly detected for the first time. However, possible non-detection at the proposed sensitivity levels will be of equal scientific importance, as it will suggest very different chemical paths for the transformations of Fe than expected. | Outflows, jets and ionized winds | ISM and star formation | 2016-05-04T12:34:44.000 |
| 889 | 2013.1.00096.S | 6 | The Lowest Metallicity Molecular Clouds | The structure of star-forming clouds at low metallicity is predicted to be different from that at high metallicity. As the metallicity drops, the cold and dense, CO-emitting part of a cloud where stars form shrinks relative to the warm photo-dissociation region (PDR) around it. The H_2 part can become much more extensive than the CO, and the HI layer around all of this can be more extensive still. We propose to obtain 12CO(1-0) maps of 3 metal-poor dwarf galaxies that span a range of metallicity down to 5% of solar. For these regions we also have Herschel maps of the PDRs and VLA maps of HI at high spatial and velocity resolution that show the cloud and its relation to the rest of the galaxy. The sequence of molecular clouds at decreasing metallicity will show us the changing cloud structures and allow us to calibrate the CO fractional mass. We will also address the question of what effect the shifting boundary between HI, PDR, and CO has on the star formation rate per molecule. These data will test star formation models that include the formation of H_2 and will improve our understanding of star formation in the metal-poor early universe. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2016-03-03T13:13:59.000 |
| 890 | 2019.1.00260.S | 201 | How is star formation regulated in merging galaxies? | Although it is well-established that galaxy mergers can enhance galactic star formation rates (SFRs), the details of this process remain poorly understood. For example, are central starbursts driven by higher gas surface densities, or by higher star formation efficiencies? Can extended star formation be triggered by tidal/compressive effects? Does outer disk star formation suppression occur due to removal of the gas reservoir? Answering these questions requires a statistically significant sample of mergers tracing a range of interaction stages, for which spatially resolved SFRs and gas maps can be combined. We propose to study the "evolution" of molecular gas and SFR in nearby mergers selected from the SDSS MaNGA integral field spectroscopy survey. We have identified a unique sample along the merger sequence: first passage, apocenter, coalescence, and post-coalescence. By combining the kpc-scale MaNGA SFR maps with ALMA CO maps taken on the same scale, we will constrain the mechanism of merger-triggered star formation and the possibility of merger-driven galaxy evolution, e.g. the growth of supermassive black holes and the transformation from star-forming into early-type galaxies. | Merging and interacting galaxies | Galaxy evolution | 2021-03-05T19:52:52.000 |
| 891 | 2013.1.00254.S | 0 | A Comprehensive View of Magnetic Fields around Young Protostar NGC 1333 IRAS 4A | The hourglass morphology of NGC 1333 IRAS 4A's magnetic field structure has been seen as the textbook example for low-mass star formation under the influence of magnetic field. We have obtained SMA dust polarization data with all available array configurations. ALMA now offers unprecedented high sensitivity at high angular resolutions and high image fidelity that, with the observations we request, we will be able to (1) obtain the most comprehensive view of magnetic field structure around a low-mass proto-binary and trace the variation of the field morphology at the Class 0 stage within ~ 30-1300 AU scale range, (2) reliably test the theoretical models, and (3) probe the turbulence power spectrum and its energy dissipation scale in the envelop. | Low-mass star formation | ISM and star formation | 2017-03-08T20:22:47.000 |
| 892 | 2016.1.01217.S | 32 | Large spatial scale interaction of gas phase Si-C molecules and dust grains | Si-C bearing molecules (SiC, Si2C, and SiC2) are related to the dust formation processes in the envelopes of C-rich stars since grains are mainly composed of silicon carbide and also carbonaceous material. These molecules are efficiently formed in gas phase, close to the stellar photosphere as a consequence of different chemical processes. Then, in the dust formation region (5-20R*), they are likely to condense onto grains due to their highly refractory nature. Beyond this region, the abundances of Si-C bearing molecules are expected to decrease until they are eventually re-formed in the outer shells of the circumstellar envelope owing to the interaction between the gas and the interstellar UV field. Motivated by our recent discoveries about Si-C bearing molecules toward IRC+10216, we propose to observe several lines of Si2C, SiC, and SiC2, in order to map the regions where these molecules emit. The proposed observations will allow us to study their radial abundance profiles as well as the chemical processes that form them at intermediate and large spatial scales, as well as the time-dependent chemical evolution of Si-C bonds carriers along the circumstellar envelope of IRC+10216. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2018-05-25T11:59:05.000 |
| 893 | 2022.1.00548.S | 5 | Neptune's High-Altitude Wind Chill from ALMA | We know much less about the atmosphere of Neptune, and the other ice giant planet Uranus, compared to other planets like Earth and Jupiter. Processes such as convection can generate storms that can affect a planet's upper atmosphere; a region that is also strongly influenced by its seasons, which last 40 years on Neptune. Therefore, studying the motion and structure of a planet's upper atmosphere investigates the relative strength of effects operating over various timescales and across large distances between different planetary region. We propose to study the dynamics of Neptune's stratosphere, where the competition between seasonal effects and processes such as convection can affect different large-scale circulation patterns present in the atmospheres of Earth, Jupiter, and even exoplanets. The ice giants are considered an analogue for a large fraction of exoplanets discovered and ALMA's spectral and spatial resolution make it well-suited to study Neptune. The 2022 Planetary Science Decadal Survey top priority science questions Q6 & Q7 ``studying the evolution, climate, structure, and dynamics of giant planet atmospheres" [4] are focus points of our proposal. | Solar system - Planetary atmospheres | Solar system | 2024-07-20T19:24:12.000 |
| 894 | 2023.1.00227.S | 9 | Physics of low-metallicity molecular clouds with ALMA | Star formation (SF) in dwarf galaxies occurs at the brink of the dynamical balance between gravity, turbulence, pressure and cooling. To probe SF physics in this metal-poor low-pressure regime, we propose a CO(2-1) pilot study at 3pc resolution of 4 nearby dwarf galaxies within 5 Mpc and having CO(3-2) detections with APEX. Only with this resolution is it possible to retrieve the tiny CO-emitting clouds preponderant at low metallicity. All targets are far-infrared (dust) emitters, and have a vast range of ancillary data to trace atomic gas, dust extinction, and young stellar populations. The ~2,100 clouds we expect to detect across the sample give statistical leverage to address: (1) the cloud dynamical state and lifecycles; (2) the effects of stellar feedback; and (3) with ACA+TP, the dependence of the conversion of CO luminosity to H2 mass, alphaCO, on CO surface brightness and spatial scale. Our proposed observations will be the first systematic study of the regulating mechanisms at low metallicity and will test emerging theories of SF as a dynamical balancing act. | Dwarf/metal-poor galaxies | Local Universe | 2025-05-02T19:09:38.000 |
| 895 | 2022.1.00760.S | 17 | A kinematical study of a circumbinary transition disk | The majority of exoplanets discovered today orbit single star systems, with so far ~5% detected around binary or multiple systems. These planetary systems display a great diversity with planets orbiting either one or two of the stars. As more than 50% of stars reside in multiple systems, it is fundamental to understand how planets form in them and what drives the diversity of the population discovered so far. To address these questions, it is essential to study the dynamical interplay between multiple systems, their circumstellar disks, and the protoplanets forming therein. Yet, our observational constraints on planet forming disks in multiple systems are still limited and sparse, making it critical to study additional systems. We propose here to observe the transitional disk around the multiple stellar system of HD 34700 at high angular and spectral resolution, to identify kinematical signatures of proposed warps and companions inside its large cavity, to study its asymmetric dust continuum emission, and to investigate its prominent spiral structure that has been observed in scattered light. | Disks around high-mass stars | Disks and planet formation | 2024-07-24T20:52:15.000 |
| 896 | 2015.1.00377.S | 1 | Dynamics and chemistry of a newly formed protostellar disk | One of the key questions for ALMA is how circumstellar disks form around low-mass protostars and how their physics and chemistry evolve until the planet-forming stages. In previous Cycle 1 observations of the dense core L483 we have detected what appears to be one of the smallest 60 AU Keplerian disks around a deeply embedded 0.3 M_sun protostar. At the same time the observations show the presence of complex organic molecules within 50 AU of the protostar. We here propose to utilise the high angular resolution and surface brightness sensitivity of ALMA to follow-up these detections: we will image the inner 10 AU (radius) from the protostar to confirm the Keplerian nature of the disk and constrain its angular momentum distribution. Furthermore the observations will map the distribution of the complex organic molecules to address whether these are present in the infalling envelope, the disk itself or perhaps the interface between the two. These observations will address two coupled questions about low-mass star formation: what is the origin of complex organic molecules around low-mass protostars and when are rotationally supported disks formed around such sources? | Low-mass star formation, Astrochemistry | ISM and star formation | 2017-11-30T22:25:44.000 |
| 897 | 2016.1.00463.S | 1456 | The nature of the brightest submm galaxies | Recent submm interferometric studies with ALMA and SMA of bright submm sources from single-dish bolometer surveys have hinted that about 60% of the brightest sources (850um fluxes > 8mJy) actually represent blends of ~2-4 fainter SMGs. Corrected for this blending, the interferometric counts of SMGs show a sharp drop above S870~8mJy which implies a fundamental limit to the maximum star-formation rate in galaxies. Moreover, the level of blending observed is inconsistent with the faint SMGs being simply line-of-sight projections, instead a significant fraction of these SMGs must be physically associated with the brightest SMGs. However, the current ALMA/SMA studies comprise just ~40 submm sources and so we propose ALMA Band 7 continuum snapshots of 160 brightest (>8mJy) sources from a new SCUBA-2 survey of the 2-sq. deg COSMOS field. These observations of a statistically significant sample will allow us to better define the knee in the counts to understand its physical significance for galaxy formation, as well as reliably determine the excess of the secondary SMGs (>1mJy) and test the physical association of these faint SMGs with the brighter SMGs. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-05-28T20:09:27.000 |
| 898 | 2013.1.00346.S | 1 | The first extragalactic, extreme, low-metallicity tests of the core mass function and molecular cloud structure | The stellar initial mass function (IMF) may be predetermined by the mass distribution of 0.1--0.5pc dense cores in a cloud. Does the IMF result from a universal core mass function (CMF)? Milky Way molecular clouds follow correlations between size, linewidth, and mass; at ~30pc resolution, clouds follow the same relations in reduced metallicity dwarf galaxies, i.e. conditions similar to the era of galaxy formation. Is molecular cloud substructure universal? Scales of ~0.1pc are critical to address either of these questions: 0.1pc is the sonic scale at which gravity is expected to dominate turbulent motions in a cloud. Probably not coincidentally, it is also the characteristic scale related to the turnover in the dense core mass function. This scale is now reachable outside of the Milky Way with ALMA. 30 Doradus provides an ideal setting in which to test molecular cloud properties in an extreme setting. Our Cycle 0 observations of 30 Doradus analyzed >100 solar mass, 0.5pc clumps. We can now build on that with an informed study of solar mass, 0.1pc cores. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-01-05T21:27:05.000 |
| 899 | 2022.1.01302.S | 133 | The Fellowship of the Rings: Completing the Sample | ALMA has discovered many protoplanetary disks with ring-like structures indicative of forming giant planets. Many of these rings are detected in larger disks, but how common these sub structures are remains unknown because not all disks have been imaged at the sufficient spatial resolution. If such structures are caused by pressure bumps that stops dust from drifting inward, all large disks are likely to have rings detectable with ALMA. We propose to observe 24 protoplanetary disks at a spatial resolution of 0.12" to complete a uniform survey of extended disks (>30 au) in Taurus, Lupus, Chamaeleon, and Ophiuchus. On top of discovering new ringed disks, we will use this homogenous catalogue to characterize the prevalence of disk rings and characterize the distribution of gap width, depths, and locations to put empirical constraints on the mechanisms halting radial drift, and link this distribution with exoplanet population statistics. | Disks around low-mass stars | Disks and planet formation | 2024-06-16T07:27:37.000 |
| 900 | 2024.1.00373.S | 0 | Tracing the core mass growth in filaments | Filamentary clouds often contain parsec-scale dense clumps that become the fertile ground of massive star and cluster formation. These filaments are considered as the connecting networks which funnel materials from cloud and/or clump scales down to their embedded dense cores. However, it is still lacking direct observational evidence that the masses of embedded dense cores have been significantly increased by the filaments via funnelling material over multiple scales. Therefore, we propose ALMA band 3 continuum and lines observations of 20 filaments that encompass protocluster-forming clumps across various evolutionary phases, in order to investigate the mass growth processes of embedded dense cores in the filamentary environments. This program will provide a statistical study of the global dynamical picture of filament and their embedded core evolutions, which promise to unveil how the filamentary network promotes star formation over the time at multiple scales in massive star-forming regions. | High-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 901 | 2013.1.00469.S | 8 | The Warm Molecular Gas of VV 114 | We propose to observe the luminous infrared galaxy VV 114 in 12CO J=4-3 and J=6-5 to study the distribution of the warm molecular gas. VV 114 has been observed in 12CO J=6-5 with the Submillimeter Array; however, only one out of the three distinct regions of molecular gas concentrations was detected. Our goal is to detect all three regions and to constrain the physical conditions of the warm molecular gas. We also propose to observe 13CO J=1-0 and J=2-1 to detect all three regions and to do a radiative tranfer analysis across the entire galaxy to look for variations in the 12CO-to-13CO abundance ratio. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2016-09-01T02:14:53.000 |
| 902 | 2018.1.01038.S | 199 | Hunting For Companionship: Constraining the Close Binary Formation Mechanism in Orion Protostars | A significant fraction of all main-sequence star are found in binary/multiple systems, and this high fraction of multiplicity must manifest itself during the star formation process. Using ALMA in Cycle 3, we surveyed 331 protostars in the Orion molecular clouds at 0.08" (30 AU) resolution at 0.87mm and we have obtained complementary data with the VLA at 9mm toward the 102 youngest, Class 0 protostars. From this complete sample, we have identified 40 close multiple systems with companion protostars separated by < 500 AU, in addition to more widely separated companions. Close companion protostars are thought to form either directly at these < 500 AU scales via disk fragmentation, or they form on ~1000 AU scales via turbulent fragmentation and migrate. With this sample of 40 close multiples, we aim to determine the dominant mechanism for the formation of close companion stars by searching for Keplerian circum-multiple disks and aligned outflows toward these systems. This survey of a complete sample of close protostellar multiples in the most populous nearby star forming region will provide a definitive answer to the question of how most close multiple systems form. | Low-mass star formation | ISM and star formation | 2020-06-29T04:55:35.000 |
| 903 | 2015.1.00847.S | 10 | Locate hot water vapor in protoplanetary disks | Previously water vapor has been detected in protoplanetary disks in the infrared. However, the exact size of the water-emitting region in these disks is only inferred from modeling. Here we propose to determine the location of water vapor by spectral line observations, in which the double-peaked line profile due to Keplerian orbital motion will be spectrally resolved. The velocity span directly gives the radius of the emitting region with a simple application of Newton's law. Furthermore, the water line emission can be used to constrain the water column density. With the location and column density of water constrained, a concrete picture of the origin and distribution of water vapor will emerge. We select 2 targets that have been detected with strong infrared water emission, with intermediate inclination angles so that the Doppler shift due to Keplerian orbital motion are observable. This study will test the feasibility of using ALMA to study water in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2017-09-29T21:59:06.000 |
| 904 | 2018.1.00162.S | 306 | ALCHEMI II: Filling the Band 5 gap | The ALMA Large Program ALCHEMI is aiming at an unbiased spectral scan of the nuclear region of the nearby starburst galaxy NGC 253, at 1'' resolution. At the time of writing this proposal, nearly all the ACA data of band 4, 6, and 7 have been delivered and processed by our team. The preliminary line identification and modeling already reveals a somehow surprising molecular richness even at the low resolution of the ACA. To significantly increase the legacy value of this Large Program and more importantly to guarantee robust line identification and physical conditions modeling, we propose to fill in the 40 GHz Band 5 frequency gap. In fact, as justified here, Band 5 contains intermediate to high energy transitions which are key for accurately model the excitation of linear molecules. Thus, we propose to add band 5 to the originally proposed spectral scan, which will provide full coverage from ALMA Bands 3 to 7. | Galaxy chemistry, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2020-09-10T17:31:47.000 |
| 905 | 2018.1.00126.S | 156 | Confirmation of a sample of pre- and proto-substellar objects in Lupus molecular clouds | The nearby southern molecular clouds Lupus I and III are ideal laboratories for studying the formation processes of sub-stellar objects. Our group (the SOLA consortium) has identified a set of pre- and proto-substellar candidates using ALMA Cycle 3 data at 1.3 mm. We propose observations in Band 7 and Band 3 in continuum and spectral lines in an attempt to confirm the real nature of these candidates as pre- and proto-brown dwarfs and clarify their apparent association with the Lupus clouds. The proposed observations will allow us to measure accurately the mass of the dust envelopes and dust disks surrounding these objects, to assess their dynamical state (e.g. transient versus self-gravitating condensations), and reveal the presence of large dust particle (millimetre to centimetre sizes). ALMA observations of this sample have the potential for the first time to provide a general picture of how substellar objects form and evolve, from pre-brown dwarf cores to proto-brown dwarfs. This proposal will provide an important insight on the formation of brown dwarfs. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-08-13T14:59:23.000 |
| 906 | 2017.1.01230.S | 0 | Exploring the ISM of the Brightest SMG During Peak Epoch of Star-formation with ALMA | We propose ALMA spectral line observations of an extremely bright sub-millimeter galaxy at z=2.553 identified from Herschel/SPIRE wide are maps (HERS1). With an observed far-infrared luminosity of 1.7x10^14, HERS1 is one of the brightest and most massive lensed SMGs ever found and is beleived to be the progenitors of the most massive elliptical galaxies found locally. With the proposed observations and with the help of gravitational lensing we would be able to probe ~200 pc physical scales of the ISM and to investigate molecular and atomic gas kinematics and spatial extension. In particular we aim to constrain the ISM temperature and gas density from our [CI] line ratio analysis combined with molecular transition line emissions from that of CO. This combined with our VLT/SINFONI observations of hot ionized gas would shed light on star-formation mechanisms at the brightest end of the luminosity function during peak epoch of star-formation. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-11-22T20:40:19.000 |
| 907 | 2019.1.00130.S | 62 | A decisive answer on the carbon isotopic ratio in galaxies with ALMA | The 12C/13C isotopic ratio is a good tracer of the chemical evolution of the ISM. Within the Galaxy we observe a gradient with galactocentric distance caused by the different ages of stellar population at various radii. However, after more decades of measurements, this ratio is still poorly constrained in the extragalactic ISM. Though observations point towards a high 12C/13C ratio in local starbursts and even higher ones at high-z, they may be biased both by limited sensitivity and the opacity of the more abundant isotopologues used as recently shown by our ALMA imaging project towards NGC 253. ALMA, for the first time, and making use of optically thin tracers, can finally provide the answer to this question. Here we provide a direct measurement of the carbon isotopic ratio based on C18O/13C18O. We note that the 12C/13C ratio is commonly used to derive other atomic ratios (such as O, N, and S) and therefore precise measurements of the carbon isotopic ratio are needed and finally at grasp with ALMA. The selected sources with complementary CN/13CN data will also allow us to understand the validity of using such ratio (based on brighter lines) in the extragalactic ISM. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2021-03-17T19:10:59.000 |
| 908 | 2011.0.00465.S | 0 | Warm gas in the HD142527 planet-forming disk | The gas-rich disk around HD~142527 highlights a large gap, from 10 to ~140AU, suggestive of gaseous giant planet formation. We have recently imaged a substellar object inside the dust gap, orbiting at 30~AU. The radius of the gap's outer edge varies by a factor of 2, in a morphology reminiscent of eccentric orbits. Is HD~142527b responsible for clearing the gap, as expected from core-accretion? Is gas accretion still going-on? Another feature of HD~142527 is evidence for azimuthal variations in the chemical abundances. This azimuthal structure is probably linked to the same process that shaped the gap. What is the physical state and the relative distribution of the gas and dust that are affected by the gap-clearing process? HD~142527b is a chance to observe planet formation, or its most recent wake. The gas reservoir to build it, at orbits of up to 100AU, still holds 0.1~Msun and a range of neutral and molecular phases. In particular the regions abutting the gap are expected to be warm, and best separated from the colder regions in CO(6-5). Our preliminary detection with CHAMP+ ensures signal. We propose to obtain resolved observations of HD~142527 in ALMA band 6, 7 and 9 of the dust continua and CO and HCO+ ladders. This dataset will image the imprint of the companion accretion onto the gaseous bulk mass of the disk. We will produce limits on the mass of gas interior to the gap, and constrain the physical conditions that occur in planet formation. | Disks around high-mass stars | Disks and planet formation | 2013-07-06T18:47:00.000 |
| 909 | 2016.2.00042.S | 197 | The True Aspect of Gas-rich Merging Galaxies | We request ACA 7m observations of CO(1-0) and CO(3-2) toward 3 LIRGs and 4 ULIRGs, which were already observed by the 12m array. Previous single-dish and interferometric studies by us and other have found that there is a large fraction of systems in which merger-induced star formation is spatially extended, taking place outside the central kiloparsec. This is totaly different from the clasical view of gas-rich merging galaxies (i.e., compact nuclear starburst). The primary goal of this proposal is to recover extended molecular gas structures in (U)LIRGs, and thus to investigate true properties of molecular gas in (U)LIRGs. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-08-15T10:12:44.000 |
| 910 | 2016.2.00002.S | 0 | ACA View of Filaments and Massive Star Formation | The filamentary nature of the interstellar medium and molecular clouds fuels questions about the mass assembly of molecular clumps and dense cores within these non-spherical structures. We will investigate the NGC 6334 complex, which is a nearby, massive, filamentary star-forming region. This ACA spectral line mosaic will spatially and spectrally resolve gas at different evolutionary stages and at a range of densities within the complex. These sensitive ACA observations will probe the structure and potential substructure of the NGC 6334 filament, address the question how mass is accreting onto dense cores within the filament, and investigate the relative importance of magnetic fields and turbulence across the filament. This data will inform the development of theoretical models of massive star formation. | High-mass star formation | ISM and star formation | 2020-06-25T00:00:00.000 |
| 911 | 2015.1.01068.S | 46 | Outflow Entrainment in the Vicinity of the HH46/47 Protostar | Outflow-disk system is the key to understand the star formation. We propose ALMA band 6 observations towards the driving source of the HH46/47 molecular outflow, to map the base of the outflow cavity, inner envelope and possibly the disk. The previous cycle 0 and cycle 1 observations on this source showed that the protostellar wind/jet is currently entraining ambient molecular gas along the outflow cavity walls. Although the outflow impact the core on large scale significantly, most of the entrainment happens at the inner region. Previous C18O observation also revealed a flattened structure with rotation signature and possibly Keplerian rotation towards the center. With a higher angular resolution we aim to 1) fully resolve the kinematics of the inner envelope. 2) resolve the rotationally supported disk to constrain disk formation theory. 3) map in detail the entrained gas at the base of the outflow cavity, to study different outflow entrainment mechanisms. 4) detect molecules directly launched from the disk. Together we will have a deep view of the envelope-disk-outflow connection which is the heart of star formation. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-09-30T01:02:10.000 |
| 912 | 2018.1.01830.S | 23 | High-resolution observations of a resolved AGN-SMG normal, main-sequence merger at z 5 | We propose deep, high-spatial and spectral resolution, Band 7 [CII] observations of a unique merger between a quasar and a sub-millimeter galaxy at z=4.68. The observations will allow us to determine the dynamical state of the two colliding galaxies and map the [CII] associated to the merging galaxies and debris surrounding material, including a spectacular 20 kpc tidal tail. We will determine what is the impact of the merger event on the host galaxies and study regions of enhanced [CII] emission. We will also compare the physical conditions of the gas and dust to those observed in local systems. Finally, we want to complement the [CII] observations with a low resolution, Band 6 exploration of the [NII] line in view of possible future ALMA follow up of this line. | Starburst galaxies | Active galaxies | 2020-09-13T15:16:29.000 |
| 913 | 2013.1.00824.S | 30 | Sub-millimeter H2O Megamasers in AGN Accretion Disks | Water-vapor megamasers at 22 GHz provide the only means for directly mapping gas in AGNs on sub-pc scales. In about 20% of megamasers, the emission originates in thin, edge-on accretion disks within a parsec of the central black hole and traces Keplerian rotation within the black hole sphere of influence. These disk masers yield "gold standard" masses of the supermassive black holes plus, in a few cases, angular-size distances to the host galaxies and a direct measurement of the Hubble constant. AGNs are expected to produce water masers at sub-mm wavelengths as well, but they are largely unexplored. For the first time, ALMA provides the sensitivity needed to study extragalactic sub-mm water masers. We propose to observe 321 GHz, 325 GHz, and 658 GHz water masers toward 3 galaxies with 22 GHz Keplerian maser disks. These sub-mm maser species can sample gas at different temperatures and densities than the 22 GHz lines, and they might trace the accretion disk much closer to the black hole than the 22 GHz lines. If they are bright, the sub-mm lines may greatly increase the power of megamasers to measure black hole masses, distances, and physical conditions in accretion disks. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-02-26T18:22:16.000 |
| 914 | 2015.1.01161.S | 51 | How Is Molecular Gas Affected by the Collision of Galaxies at the Collision Front | We propose multi-line imaging of interacting galaxies in ealry stage of the interaction NGC 4567/4568 pair to study the mechanism of an enhancement of star formation activity by the galaxy interaction. The condition of starburst induced by the interaction can not be understood until observing intercting galaxies before burst of star formation (i.e., early stage). The study aims to unveil: 1) the conditions of molecular gas at the collision front found with our ALMA Cycle 1 observations in giant molecular cloud (GMC) scale (<100 pc), 2) the formation mechanism of dense gas at the collision front and its relation to star forming activity, 3) direct proof of shock and their propagation. 4) difference between these physical properties with field galaxies. The method consists of imaging CO(1-0) in Band 3 and simultaneous observations of CO(3-2), HCN(4-3), HCO+(4-3), CS(7-6) and SiO(8-7) in Band 7. CO(1-0) reveals distributions of GMCs at the collision front. CO(3-2), HCN, HCO+ and CS give us information about dense gas and SiO shows where shock takes place. With ALMA's high sensivity and angluar resolution, how the galaxy interaction ignites molecular gas to violent star formation. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2017-12-05T22:24:39.000 |
| 915 | 2019.1.00636.V | 0 | Imaging massive binary black hole candidate Oj287 with the GMVA+ALMA | We propose 3 mm GMVA+ALMA observations of OJ287, one of the best candidates for hosting a sub-pc supermassive binary black hole system (SMBBH) and to study jet formation. The improvement in the north-south resolution and sensitivity provided by ALMA, and the comparison with quasi-simultaneous, resolution-matched 1 mm EHT+ALMA images could potentially spatially resolve the binary system, providing the first confirmation of sub-pc SMBBHs, prime targets for nano- and milli-hertz gravitational wave detectors. Comparison with similar campaigns in 2017, 2018, and 2019 will allow us to measure the innermost jet swing during a time period that covers already ~30% of the SMBBH orbit, providing stronger constrains on the applicability of the SMBBH model. Our continued observing campaign will also allow us, for the first time, to study the magnetic field and particle energy distribution evolution at scales not probed before in blazar jets, reaching linear scales of only ~50 Schwarzschild radii in OJ287. This will be used to test the applicability of magnetically driven jet formation models and the SMBBH scenario by comparing predictions from different GRMHD simulations. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-07-12T10:29:15.000 |
| 916 | 2017.1.01157.S | 319 | Gas vs. solid phase deuterated chemistry | Deuteration fractionation, and how it changes as star formation proceeds, is a powerful tool to establish the evolutionary stage and age of star-forming cores. However, this behaves differently depending on the molecular species used. Here, we propose to study the deuterium fractionation of formaldehyde toward eleven Galactic high-mass sources from starless cores to UCHII regions. They have well measured deuteration fractions with single dish telescopes for H2CO, N2H+, NH3 and CH3OH. High-resolutions NH3 maps are available for them, but the size of the H2CO cores are still unknown, which makes the column density calculation uncertain. The large beam size of available single dish observations may contain objects in different evolutionary stages. HDCO and D2CO can be produced both in the gas phase and on grain surfaces, and our single dish observations suggest that H2CO and its deuterated species, form mostly on grain surfaces although some gas-phase contribution is expected at the warm HMPO stage. Interferometric observations are needed to separate the HDCO and D2CO emission originating from the small and dense cores and to disentangle their origin in high-mass star-forming regions. | High-mass star formation, Astrochemistry | ISM and star formation | 2019-09-01T19:17:41.000 |
| 917 | 2015.1.00041.S | 164 | Orion Disk And Multiplicity Survey | The formation of disks and multiple systems is thought to begin during the early phases of the star formation process. However, sufficient numbers of young protostars (Class 0 and I phases) have not been observed at high enough resolution to determine when and where most multiples form and whether or not large disks are common. To make significant progress in these areas of star formation study, we propose an unbiased ALMA Band 7 survey of the 331 known protostars in the Orion A and B molecular clouds at 0.09" (38 AU) resolution. Orion is the only massive star forming region within 500 pc and the resolution and sensitivity of ALMA will enable us to characterize the separation distribution of multiple systems and size distribution of protostellar disks. CO and 13CO (J=3-2) lines will be observed simultaneously to determine the compact outflow directions and observe disk kinematics. This study will be the largest and most complete high-resolution submillimeter survey of protostars ever undertaken and will significantly improve our understanding of the formation mechanisms and prevalence of close multiples and disks during the early stages of star formation. | Low-mass star formation | ISM and star formation | 2018-10-03T14:05:19.000 |
| 918 | 2015.1.00404.S | 114 | Gas fueling and outflow around massive black holes | The effects of feedback and fueling of active galactic nuclei (AGN) play a fundamental role in galaxy evolution, through quenching star-formation activity and growing massive black holes in the centers of galaxies. Our NUclei of GAlaxies (NUGA) study of molecular gas in ~20 AGN circumnuclear regions on 100 pc scales has shown that nested, kinematically decoupled bars are able to effectively funnel gas into the nucleus, although only in 1 out of 3 cases. It is possible that different time-scales and episodic fueling are to blame, or that AGN (and supernovae) feedback halts the process. To further characterize fueling and feedback in AGN, we have defined a small sample of AGN that spans a factor of 100 in AGN power and a factor of 10 in star-formation rate. We propose to map the morphology and kinematics of the cold dense gas in five nearby Seyfert/LINER nuclei at the unprecedented spatial resolution of 0.14" (8-16 pc). We will quantify the AGN fueling by measuring torques on the gas with our well-tested algorithm, and characterize molecular outflows as well as compare their properties with near-infrared SINFONI spectral cubes already in hand. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-10-22T03:31:34.000 |
| 919 | 2023.1.00026.S | 0 | Virgo High-resolution CO(2-1) Survey: Dissecting Galaxy Quenching with Molecular Cloud Scale "Micro-physics" | The external environments around galaxies can exert substantial influence on galaxy evolution. However, the small-scale "microphysics" underlying these environmental effects, such as changes in the interstellar medium (ISM) structure, dynamics, and star formation efficiency, is still not fully understood. We propose a sub-arcsec resolution CO(2-1) survey targeting 40 late-type galaxies in the Virgo Cluster that have unmatched multiwavelength coverage, including optical IFS data from an ongoing VLT/MUSE Large Program. Pairing this survey with archival data for a control sample of non-cluster galaxies (PHANGS), we will (1) measure changes in the demographics and spatial distribution of star-forming clouds at different cluster in-fall stages, (2) characterize the in-disk and extra-planar gas flows in cluster galaxies experiencing various levels of stripping, and (3) identify the fundamental cause of star formation efficiency variations as functions of galaxy properties and in-fall time. This project will be the first to connect megaparsec-scale effects on galaxy evolution to the ISM and star formation "microphysics" on tens of parsec scales. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2025-08-23T20:50:30.000 |
| 920 | 2023.1.00907.S | 0 | Tomography of an edge-on Disk: the Flying Saucer Case | The studies of edge-on protoplanetary disks are now recognized as powerful tools to constrain the radial and vertical layered structures of gas and dust. We propose to observe the Flying Saucer, a typical molecular-rich edge-on disk in rho Oph, at high enough angular resolution (0.18'' or about one scale-height in the outer disk) to provide 1) a direct reconstruction of the thermal profile using the optically thick and thermalized lines of 12CO,13CO and C18O 2-1 and 2) a direct view of the location of the molecular layer by observing a few key molecules that are abundant in disks (HCN, CN, CS and H2CO). These new observations will be used to calibrate (thermo)-chemical models on observed line emission not only as a function of radius, but also as a function of height above the disk mid-plane. The resulting tomographic data will be put in open access form to provide a coherent data set for comparison with predictions from any thermo-chemical code. | Disks around low-mass stars | Disks and planet formation | 2025-09-26T09:17:30.000 |
| 921 | 2018.1.00199.S | 3 | The Role of Spicules in the Low Solar Atmosphere | Solar spicules are ubiquitous, dynamic, filamentary jets extending several thousand kilometers into the solar atmosphere with temperatures of $\sim10^4$ K. Despite decades of study their origin, properties, their role in the energy and mass budgets of the solar chromosphere and corona have been uncertain. It has been only recently that their observational characteristics have been established with some confidence, thanks to several space-based missions launched in the past decade. These observations have provoked intense interest, leading to proposals that certain spicules play a central role as a source of hot plasma in the solar corona. We propose to use ALMA to characterize statistically the thermodynamic properties of spicules at the solar limb by measuring the ensemble of height(s) above the limb and the temperature(s) where they become optically thick using both bands 3 and 6. These observations will be compared in detail with optically thin diagnostics based on optical, UV, and EUV observations from space and will be used jointly to constrain the mass and energy flux of spicules into the low solar atmosphere in both magnetically open and magnetically closed environments. | The Sun | Sun | 2020-09-17T15:45:31.000 |
| 922 | 2016.1.00461.S | 11 | Spatial and spectroscopic identification of SCUBA2 sources associated to a proto-cluster at z=2.5 | Proto-clusters at z>2 are the sites where the present-day early-type galaxies are in their vigorous formation phase with intense star formation activities. We have recently obtained a deep SCUBA2 map of the densest proto-cluster at z=2.53 with 15hrs net integration. It has detected nine 850um sources in the cluster core within our HST/WFC3 images, which are stretched along the filamentary structure connecting the two prominent dense clumps traced by our narrow-band selected H-alpha emitters, suggesting their physical association to the cluster. However, the 13-arcsec diameter size of the SCUBA2 primary beam does not allow us to make source identification. We here propose to perform ALMA CO(3-2) line survey in Band-3 with 1.5" angular resolution on these 9 sources. It will unambiguously identify their optical/NIR counterparts spatially and their cluster membership spectroscopically. Once their physical associations are confirmed, we can unveil and recover the starburst activities in the proto-cluster which are otherwise deeply hidden by dust, which then allows us to investigate the nature of those likely progenitors of cluster elliptical galaxies with our multi-wavelength data. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2019-05-07T08:09:43.000 |
| 923 | 2015.1.00732.S | 14 | Illuminate NGC 253 Nuclear Starburst by Ionized Gas Imaging in Parsec Scale with ALMA | We propose a high spatial resolution observation of thermal free-free continuum emission in 105 GHz (Band 3) together with a hydrogen recombination line (H40alpha) toward a nuclear starburst galaxy NGC 253 in the ALMA Cycle 3. Based on data taken in the ALMA previous cycles, we successfully assessed physical properties of ionized gas. However, the limited spatial resolution data have constrained us to do just rough estimate of those values. Observations with very high spatial resolution down to the compact HII region scale (0.''08=1.3pc) assisted by the long baseline capability will push back the past limitations, and they provide not only ionized gas properties unambiguosly but also essential insights on the nature of the starburst activity. | Starbursts, star formation | Active galaxies | 2018-02-27T23:20:01.000 |
| 924 | 2015.1.01042.S | 57 | Establishing OH+ as a robust outflow tracer for high redshift galaxies | We propose to establish the use of the OH+ lines as a robust outflow tracer in luminous high-z galaxies. The OH+ line displays pronounced P-cygni profiles in local ULIRGs, where the line is ubiquitous and about half as bright as CO lines, and as such should be an ideal outflow probe of high-z galaxies for ALMA. We target 5 gravitationally lensed high-z ULIRGs (3 at z=2-2.5, 2 at z=3-3.5), with spectroscopic redshifts and good magnification models, to test this method. We use a setup combining OH+ with the nearby CO(9-8) line, which provides a direct measurement of the velocity of any OH+ emission or absorption with respect to the bulk gas. We will measure outflow velocities as a function of position over the galaxies, pinpoint the origin of the outflow and assess the relation between outflow velocity infrared luminosity and surface brightness. Bright detections will be followed up at high resolution in a future cycle. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-08-11T17:49:49.000 |
| 925 | 2019.1.00571.S | 42 | The chemical evolution of complex organic molecules from hot core to disk in S255IR NIRS3 | Although the chemical richness and complexity of hot cores have been largely studied, those for the MYSO disks have never been explored because the detection of the MYSO disks is rare. In addition, the accretion process in MYSOs over the scale from thousands to hundreds AU is still poorly understood both in the physical and chemical aspects. Recently, an important laboratory to explore these unknowns has been found; an accretion burst event has been detected for the first time toward a MYSO, S255IR NIR3, which harbors a chemically rich hot core and a rotating disk. Taking advantage of this unique situation of S255IR NIRS3, we aim to investigate the ice composition from the hot core to the disk. The kinematics traced by optically thin COMs lines will allow us to disentangle the disk from the hot core. The distinguished chemical complexity and richness in disk and hot core will provide a special opportunity to self-consistently study the evolution of ice composition in the disk material after being accreted from the inner envelope. Therefore, we propose the spectral scan observation in two configurations, to study the various COMs in the disk and hot core in a coherent way. | High-mass star formation, Astrochemistry | ISM and star formation | 2022-11-03T19:14:36.000 |
| 926 | 2023.1.00044.S | 0 | Unveiling the magnetic field structure in the nuclei of the Arp 220 galaxy merger | We propose full polarization, dust continuum and molecular ALMA Band 7 observations of Arp 220, the most nearby ULIRG, to study the properties of the magnetic field and determine the role in the processes that occur when two galaxies merge. The combination of dust and molecular line polarization measurements will allow us to trace the circumnuclear and the ISM in both nuclei as both phases are dominated by molecular gas. Arp 220 is arguably the best possible case to map with ALMA for the first time the distribution of the magnetic field in a ULIRG, with high angular resolution and high S/N, through polarimetric observations. Our requested observations will yield a spatial resolution of about 50 pc, enough to resolve the magnetic field structure in both nuclei, as well as of the surrounding gas. This will allow us to to study the existence of correlations between the magnetic field properties and the morphological and the kinematical properties of the gas. Crucially important, these observations will allow us to disentangle which energy process, turbulent kinetic vs self-gravitational energy of a disk, dominates the galaxy merger, and how the magnetic field is amplified. | Merging and interacting galaxies | Galaxy evolution | 2025-09-23T17:13:59.000 |
| 927 | 2019.2.00097.S | 80 | Probing the physical and chemical structure of dense cores: toward understanding methanol formation | Stars and their disk form out of cold and dense core. It is thought that some of the initial material survive the disk formation process and is inherited by the planet-forming material. Methanol, an important complex organic, forms on dust grain surfaces via CO freezeout. In the same region, molecular gas lines from N2H+ and DCO+ can be detected with ALMA to trace the CO freeze out regions. We propose to map these molecular lines in Bands 3 and 4 around four dense cores. These dense cores were observed with SPITZER which show molecular solid features along the line of sight away from the known protostars. The proposed observations will provide the temperature and density of the gas around the SPITZER observations. By comparing ALMA observations to SPITZER spectra, it will be possible to constrain the physical and chemical structure at the locations where methanol ice is forming. The large-scale kinematics will then provide the path that the material takes as the disk forms. | Low-mass star formation, Astrochemistry | ISM and star formation | 2022-09-22T18:37:25.000 |
| 928 | 2011.0.00635.S | 0 | Do dust holes in transitional disks still contain cold gas? v1.9 | Transitional disks with large inner dust cavities are thought to be the best laboratories for studying disk evolution during the planet-forming stage. Little is known about the gas inside dust cavities, yet this gas significantly affects planet formation through gas-grain dynamics and planetary migration. We propose here pioneering ALMA Band 9 observations of CO 6-5, C17O 6-5 and the millimeter continuum to provide the first deep searches for molecular gas inside a dust hole. The Herbig Ae star IRS48 in Ophiuchus is one of the very few disks known to have a large enough hole to be imaged during ALMA Cycle 0. This disk is unusual in that it shows very strong PAH emission inside the hole, yet the mid-IR continuum and CO infrared lines show a ring with 30-40 AU radius. The huge leap in sensitivity provided by ALMA at high frequencies allows a large range of gas masses inside the hole to be tested, down to a fraction of a Neptune mass. This, in turn, allows the origin of the hole in this disk to be determined: substellar or planetary mass companions versus photoevaporation versus grain growth. | Disks around low-mass stars | Disks and planet formation | 2013-10-10T14:39:22.000 |
| 929 | 2022.1.00662.S | 206 | The Mean Free Path of Ionizing Photons at z = 5.6: A Robust Constraint on Reionization | The physics and timing of reionization carry important implications for the formation and evolution of the first galaxies in the early Universe. Recent observations based on QSO spectra have challenged the prevailing consensus that reionization ends by z=6 or earlier. A key part of this challenge is the mean free path of ionizing photons, which is expected to evolve rapidly near the end of reionization. Current measurements of the mean free path indicate rapid evolution between z = 6 and 5 but still allow a broad range of reionization histories. We propose to use ALMA to measure the systemic redshifts of 22 recently discovered QSOs using the [CII] 158 micron line. Combined with Keck optical spectra, this will enable us to precisely measure the mean free path at z=5.6 for the first time. The new observations will show how the mean free path evolves over 5 | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-02-04T02:18:26.000 |
| 930 | 2024.1.01104.S | 0 | Identifying targets for cross-checking blackhole mass measurements | The co-evolution of supermassive black holes (SMBHs) and their host galaxies is crucial to galaxy evolution. However, though fundamental to this co-evolution, scaling relations are built on a relatively small number (<200) of direct SMBH mass measurements and a variety of methods. In the ALMA era, a new method of probing the near-Keplerian rotation of CO discs around SMBHs shows great potential. To further cross-check the CO dynamics method with other methods, we propose standalone ACA observation of 19 galaxies with 19 hours in total to search for suitable targets for subsequent high-resolution follow-up. The sample is from a comprehensive compilation of SMBH masses from different methods and is required to exhibit regular dust features (in HST images) as an indication of regularly rotating CO discs, among other criteria. Based on success in the last cycle, we will analyse the morphology and kinematics of molecular gas, thus identifying promising targets for the next step. As a by-product, we will study molecular gas properties on kpc scales with ACA data, again paving the way to and selecting suitable targets for future cloud-scale studies. | Galactic centres/nuclei | Active galaxies | 2025-10-08T19:20:16.000 |
| 931 | 2011.0.00011.SV | 0 | Science verification observation of VY CMa | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Evolved stars - Shaping/physical structure, Evolved stars - Chemistry | Stars and stellar evolution | 2016-06-24T14:02:07.000 |
| 932 | 2021.1.01561.S | 6 | Gas kinematics and dust trapping in the only known circumtriple disk | The recent ALMA observations towards the large circumtriple disk GW Ori have resolved it into three dusty rings which are inclined with respect to each other and with respect to the orbital plane of the host stars. These rings are likely precessing. If they can form planets, it may explain why some planets are on oblique or retrograde orbits. We propose to perform dust polarization observations at Band 4 and 7, and perform high angular/velocity observations of the high excitation lines CO J=3-2 and HCN J=4-3 at Band 7. The main goals are (1) base on diagnosing dust self-scattering polarization and dust spectral indices to discern whether or not there are grown dust in the rings which is precursor of planets, and (2) to hunt the unseen planets based on examining the planet-induced kinematic features (e.g., doppler flips or linewidth broadening). Moreover, this project will serve as another attempt to detect CO polarization which is a rather novel science case. Finally, the requested molecular line observations will help understand the global gas kinematics in much greater detail. This will be a unique opportunity to understand the so called disk tearing mechanism. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2023-05-08T00:00:00.000 |
| 933 | 2023.1.00681.S | 0 | The life cycle of dust and gas: CO observations of AGB stars in the Magellanic Clouds | Stars on the asymptotic giant branch (AGB) and supernovae both contribute gas and dust to the ISM, but their relative importance remains uncertain. To better quantify the contribution from AGB stars, it is vital to quantify how their wind outflow velocity (Vexp), mass-loss rate (MLR), and dust-production rate (DPR) depend on luminosity (L) and in particular, metallicity. ALMA previously detected CO 2-1 emission in four carbon stars in the Large Magellanic Cloud, out of four targeted, all of which have estimated DPRs. These observations suggest that Vexp is significantly lower than in similar Galactic objects, but the sample was very small. In parallel, recent theoretical models for dust growth have predicted properties (Vexp, gas-to-dust ratio, MLR, L) for 11000 AGB stars in both the Small and Large Magellanic Cloud. We propose to observe 41 objects in these nearby galaxies in CO 2-1 in order to cover the parameter space in these quantities. Radiative transfer modelling of the CO profile (Vexp, intensity and shape) and the dust (via the spectral energy distribution) will provide critical tests of predictions on how Vexp, dust-to-gas ratio and MLR depend on stellar parameters. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2025-07-31T16:58:06.000 |
| 934 | 2012.1.00997.S | 2 | Probing the SiO content in HH212: a clue to the origin of protostellar jets | This is a follow-up of our accepted (but not yet observed) ALMA Cycle 0 project 2011.0.00647.S (rated in the top 10% of all projects) aimed at mapping CO(6-5), CO(3-2), and SiO(8-7) in the HH212 protostellar microjet in order to measure its temperature, mass-flux, and a lower limit to its SiO abundance. Here, we propose to take advantage of the enhanced ALMA sensitivity in Cycle 1 to observe in 1.6h of ALMA band 7 time) the isotopologue 30SiO in HH212 and obtain a much more sensitive constraint on SiO abundance, and thus on the jet dust content, than possible up to now. In case our accepted Cycle 0 observations cannot be performed before the start of Cycle 1, we also add for safety the corresponding 2 settings here, as they provide unique complementary information that remains essential for our $^{30}$SiO interpretation and provide key new constraints on the jet launching process. They represent only 1.5 extra hours (1h in Band 9 and 0.5h in Band 7) and will of course be canceled if the Cycle 0 project is observed as planned. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2015-08-25T14:58:56.000 |
| 935 | 2023.1.00774.S | 0 | LIghting up dark matter with dust: probing the anomalous lensing substructure in J0946+1006 | Dark matter "subhalos" around massive lensing galaxies slightly distort the gravitational arcs formed by background sources. This effect can constrain the population of low-mass (~10^8 Msun) halos, and distinguish between dark matter types (cold, warm, etc). Observationally however, the most striking detection so far is of a substructure in the lens J0946+1006 that is far more massive than should exist in any current model, without hosting a luminous galaxy. The evidence for this structure rests on modelling HST images of arcs from a bright z=0.6 background spiral. The detailed arc structures cannot be reconciled with smooth models for the lensing galaxy, and seem to demand an extra mass of >3x10^9 Msun within a ~1 kpc aperture, with no luminous counterpart. The regions in the arcs that are closest to the perturber, and which are most sensitive to its influence, are notably red, showing the likely presence of dust in the background galaxy. Here, we propose ALMA continuum observations to detect this dust in emission, to determine its lensed structure at high angular resolution, and hence better constrain the properties of the apparently CDM-defying dark structure. | Gravitational lenses | Cosmology | 2025-01-04T15:38:13.000 |
| 936 | 2013.1.00180.S | 10 | Does the CO excitation in an outflow differ from that in the ambient medium? Insights from 4C12.50 | Black holes have been claimed able to heat the gas in galaxies via jet/radiation-driven shock fronts. Indeed, evidence of heating of the molecular gas in an AGN-driven outflow was recently discovered: using Spitzer, IRAM Plateau de Bure & 30m telescope, and Herschel data of a radio-loud and ultraluminous-infrared galaxy, 4C12.50, we demonstrated that the mass ratio of warm (~400K) to cold (~25K) gas is >=30 times higher in the outflow than in the ambient medium. Our conclusion that the accelerated gas is heated is robust against major sources of uncertainty including the CO-intensity-to-H2-mass conversion factor, the warm gas temperature from rotational H2 lines, and the warm gas mass probed by high-J CO lines. Motivated by this result, we request CO(1-0), (3-2), (4-3), and (6-5) observations to compare the spectral line energy distribution in the outflow and in the ambient medium of 4C12.50. Our goal is to test whether the gas heating is detectable as an excess emission by CO molecules in intermediate rotational states J, facilitating the discovery of outflows at intermediate/high z. We request 3.2 hrs for a project that can serve as a reference for future outflow searches. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2016-07-30T00:00:00.000 |
| 937 | 2017.1.01112.S | 0 | Triggering of Dusty Star-Forming Galaxies in Massive, Rapid-Forming Clusters | Recent discoveries of z>2 proto galaxy clusters with extremely rich population of dusty star-forming galaxies (DSFGs; SFR>100Msun/yr) represent the most active formation and assembly phases of massive galaxy clusters. These protoclusters are ideal sites to study the early phase of cluster formation and infer environmental influences on galaxy evolution. Here we propose to obtain spatially resolved CO (3-2) maps (with 0.3 resolution) for a total 10 DSFGs in the COSMOS z=2.10 and MRC1138-256 z=2.16 protoclusters. Our proposed observations will double the existing sample of protocluster DSFGs with CO. Through measuring the gas depletion time, dynamical status, and the spatial extent of star formation, this proposal will provide strong constraints on the merger-driven or accretion-driven nature of protocluster DSFGs. Our understanding of the physical drivers of these DSFGs will provide the best opportunity to uncover the roles of large scale environments play in driving these DSFGs as compared to their counterparts in the field, and provide important insight into the early phase of galaxy cluster assembly. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2019-11-22T16:10:07.000 |
| 938 | 2011.0.00958.S | 0 | Imaging the Brightest Starbursts in the Universe | We propose detailed ALMA imaging of an exciting new population of rare, ultra-bright, high redshift, strongly-lensed dusty star forming galaxies (DSFGs). The sources were discovered in a 2500-square-degree mm-wave survey conducted with the 10 meter South Pole Telescope (SPT). The large survey area and flux-limited mm-wave selection has allowed the SPT to find the rarest (roughly one per twenty square degrees) and highest-redshift DSFGs. The SPT team is now in the midst of a systematic and coordinated follow-up program to characterize and fully exploit the scientific potential of these sources. With its exquisite angular resolution and sensitivity, ALMA is crucial to the success of this follow-up program. ALMA observations will allow us to construct accurate lens models which will enable us to make robust estimates of the source magnification and, hence, the intrinsic properties of the lensed DSFGs, thus opening a new window on star and galaxy formation in the high-redshift universe. ALMA observations of these lensed systems will enable unique and powerful investigations of what would otherwise be inaccessibly faint high-redshift members of the population responsible for the cosmic infrared background. The ALMA observations will also complement approved HST observations of a subset of the sample, allowing side-by-side comparisons of HST and ALMA images with matching resolution. These images, in addition to their use in groundbreaking science, will demonstrate the power of ALMA to the public. The resulting data set will also have high legacy value to the community. As the sources are extremely bright (345 GHz fluxes span 40 to 200 mJy), our proposal requests a total of only 2.6 hours to image 47 sources in Band 7. | Starburst galaxies, Gravitational lenses | Active galaxies | 2013-08-28T13:02:00.000 |
| 939 | 2018.1.01073.S | 38 | Mapping Envelope Kinematics in Filamentary Environments: Completing the Pilot Program | We propose to complete a pilot Band 6 study of the envelope kinematics of three Orion protostars selected from the Herschel Orion Protostar Survey. These observations are motivated by our recent ALMA maps of three edge-on, relatively isolated protostars in Orion, showing evidence for highly asymmetric infall, in sharp contrast to typical models which assume axisymmetry. We propose to extend our infall study to three protostars found in filamentary environments. These environments are selected to span the range of surface densities/mass to length ratios in the Orion A cloud. We can then study the processes that control low mass star formation by comparing infall between filamentary and (previous mapped) isolated sources and between filaments of different densities. We will use C18O and 13CO to trace envelope motions from the filament to the protostars, augmented by H2CO as a dense gas tracer, N2D+ to trace gas where CO is frozen out, and CO and SiO to trace outflows. Cycle 3 observations were obtained with the ACA and TP, we ask for time to complete the 12 meter observations here. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2020-07-09T17:17:24.000 |
| 940 | 2016.1.00262.S | 1 | Detecting the Circumplanetary Disk around the Spiral-Arm-Driving Planet in a Protoplanetary Disk | A pair of giant spiral arms in a near m=2 rotational symmetry has recently been revealed in NIR scattered light observations of MWC 758, a protoplanetary disk at 280 pc. Using hydrodynamics and radiative transfer simulations, we have proposed a companion-disk interaction model to account for the arm morphology in the system. We predict the presence of a giant planet about 10 MJ in mass at ~160 AU (0".6). The planet forms a circumplaneary disk in our model. Based on synthetic ALMA Band-8 observations of our model, we conclude that both the spiral arms and the circumplanetary disk can be significantly detected in continuum emissions with 0".05 angular resolution. We therefore propose such observations to look for these structures, and to measure the column density contrast of the spiral arms. In particular, this team has just conducted deep NIR AO imaging observaiton of MWC 758 using Keck/NIRC2, and the predicted planet has been tentatively detected. Once confirmed, the planet will be the first-ever feature-producing planets definitely predicted by disk-planet interaction models, and will likely open another door in planet detection. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2018-10-03T14:05:19.000 |
| 941 | 2019.1.00533.S | 40 | Constrain the ISM conditions and ionization states at high redshift with mult-transitions of the H2O+ and H2O lines | Understanding the ISM of the most dust-obscured galaxies at high redshift requires a detailed knowledge of the physical conditions of the ISM, the radiation field and how they interact with each other. In the submm galaxies, the chemistry is mainly driven by the ion-neutral reactions, tightly related to the ionization by cosmic rays (CR, or X-rays) that can penetrate deeply into the shielded molecular gas. Ionization by CR is a fundamental process and shapes our knowledge of the ISM and star formation. Thanks to strong lensing, we are now able to detect various transitions of the magnified H2O and H2O+ lines at high redshift. Here we propose observations of the ground transitions of H2O+ and H2O, as well as a J=3 H2O+ line in two lensed sources SMGs that have previsouly detected multiple lines of H2O and J=2 H2O+. Combined with our existing data, the new observations of the J=1,3 H2O+ and J=1 H2O lines will enable us to constrain the physical conditions of the ISM and to estimate the abundance of H2O and H2O+ and constrain the ionization states with ratios of H2O/H2O+ both in both the outer disk and, most importantly, in the warm dense nuclear regions of the galaxies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2021-03-02T15:30:45.000 |
| 942 | 2018.1.01591.S | 45 | Do strong gravitational lenses have too much low mass substructure? | For over two decades, there has been a discrepancy between the number of predicted sub-haloes in CDM simulations and those actually observed around the Milky Way. Gravitational lensing provides a clean method for probing directly the projected matter density distribution of galaxies, even at low mass-scales, as a sub-halo can significantly modify the image magnifications, and hence their observed flux-ratios. Therefore, anomalous flux-ratios are a key method in exploring the sub-halo population in distant massive galaxies. We have recently re-analysed ALMA archival imaging of a lensed AGN, finding that the synchrotron mm-continuum shows a flux-ratio anomaly consistent with a CDM sub-halo, but also, for the first time, we see an anomaly in the unresolved high excitation gas close to the AGN black hole. Here, we propose a pilot survey of 4 radio-quiet lensed quasars, to search for anomalous flux-ratios in the compact mm-continuum and/or molecular gas. These data will potentially open a new observational avenue for efficiently studying the abundance of low mass haloes at cosmological distances, providing an independent test of galaxy formation/dark matter models. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2021-01-10T20:27:06.000 |
| 943 | 2011.0.00725.S | 0 | The First Accurate Measurements of the Growth Rates of Galaxies and Black Holes in a Distant Protocluster v1.4 | A key goal of observational cosmology is to measure the link between the growth of galaxies and large-scale structure. We have been addressing this issue with deep multi-wavelength observations of the z~3.09 SSA22 protocluster, a likely progenitor of a massive galaxy cluster. We have shown that a ~6 times larger fraction of protocluster galaxies host AGN activity than found in the field, indicating that the growth of black holes is highly accelerated in this distant high-density region. But what is happening to the host galaxies - do they track this enhanced black-hole growth rate or are they growing more quickly or slowly? Here we propose for ALMA continuum observations of the AGNs and galaxies in the central region of the SSA22 protocluster. With these observations we will constrain the rest-frame far-infrared luminosities of the AGNs and galaxies in the protocluster and measure their star-formation rates and specific star-formation rates to (1) determine whether the growth of the protocluster-AGN host galaxies are more rapid than that found for AGNs in field-galaxy regions, and (2) determine whether the host-galaxy growth rates are comparable for the AGNs and the galaxies in the protocluster, or whether the growth of the galaxy lags (or leads) the growth of the black hole in distant high-density regions. | High-z Active Galactic Nuclei (AGN), Galaxy Clusters | Active galaxies | 2013-12-11T09:10:18.000 |
| 944 | 2016.1.00448.S | 30 | CK Vul: Unravelling a 350-year old mystery | The nature of CK Vul is a complete mystery. We will use ALMA to observe the dust in the immediate vicinity of CK Vul, with the aims of determining (a) the structure of the dust distribution, (b) the history of mass-loss, (c) the mass of dust, (d) whether there is any diffuse dust emission, (e) what the relation of the dust is to the larger structure around CK Vul, (f) the nature of the progenitor of the 1670 eruption. ALMA will add an important piece that will help us to complete the CK Vul jig-saw puzzle. | Post-AGB stars | Stars and stellar evolution | 2018-07-23T18:57:16.000 |
| 945 | 2016.1.00800.S | 34 | Finding a deeply buried, submm-opaque, AGN in the LIRG IC860 | We propose high resolution (0."04 and 0."07) Band 6 and Band 3 imaging of the exceptionally luminous emission from vibrationally excited HCN (HCN-VIB)and HC3N in the LIRG IC860. The goal is to map the hidden mid-infared nucleus traced by the vibrationally excited lines and determine if the luminosity is powered primarily by an accreting supermassive black hole (SMBH) or by a growing stellar spheroid. The ground state HCN and HCO+ lines (standard high density gas tracers) are self- and continuum absorbed and cannot be used to probe the nucleus. The vibrational lines serve as proxies for extremely high mid-IR surface brightnesses and we will resolve the hot nucleus and probe its morphology, dynamics and luminosity density. Cycle 3 345 GHz observations resolved HCN-VIB emission for the first time around a galaxy nucleus, but the emission cannot penetrate the inner extremely opaque core, hence we must go to longer wavelengths for lower dust opacities. IC860 is a representative of a class of of deeply obscured galaxies where the opaque nucleus is in a state of rapid growth. The buried activity in these Compton thick (CT) nuclei may be missed by both X-ray and mid-IR surveys. | Galactic centres/nuclei | Active galaxies | 2018-11-24T13:41:34.000 |
| 946 | 2022.1.00179.S | 20 | The Serpens-Aquilla Disk and Multiplicity Survey | We propose a survey of 170 protostars in the Serpens-Aquila star-forming region at 0.09" (~40 au) resolution in Band 7. We will characterize the multiplicity frequency, companion separation distribution, protostellar dust disk masses, and dust disk radii for the largest sample of protostars (besides Orion) within 500 pc. The origin of disks and multiplicity are rooted in the earliest stages of star-formation, but only three sizeable regions have had their protostellar multiplicity and disks characterized (Perseus, Orion, and Ophiuchus). The previous surveys discovered a bimodal distribution of companion separations and it is important to determine if this is `universal'. Similarly, disks emerge early, yet it is unclear if the protostellar disk mass and size distributions are similar across all star-forming regions. This is important given that protostellar disks (as an ensemble) are found to be 5-10x more massive than Class II disks. This survey is essential to test whether or not protostellar disks and multiplicity have similar properties across distinct star-forming regions, implying similar physical processes. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2024-08-03T18:28:49.000 |
| 947 | 2019.1.01556.S | 26 | On the universality of fibres in star forming filaments | Interstellar filaments are ubiquitous constituents of the ISM and are key to the star formation process due to their fragmentation into cores, the direct progenitors of stars. Some filaments have recently been observed to be further sub-fragmented into narrow filamentary sub-structures called fibres, the densest of which contain the star-forming cores. Fibres have been suggested in the literature to be the missing ingredient that unifies star formation across mass scales, with low-mass stars forming in low-mass clouds with a low surface density of fibres, and high-mass stars forming in high-mass clouds with a high surface density of fibres. This suggests that all dense filaments are made up of unresolved bundles of fibres, a prediction that requires thorough testing across mass scales. This is the motivation of this proposal. We propose to observe N2H+(1-0) towards the ~1700Msun SDC13, a hub-and-spoke cloud containing four merging filaments of differing intermediate line-masses. Our work so far suggests SDC13 is devoid of fibres - at 3.6kpc, only ALMA with high-angular resolution will give the definitive view of SDC13's sub-structure and its implications on star formation. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-11-10T19:50:18.000 |
| 948 | 2016.1.01339.S | 9 | Sulphur in protoplanetary disks - a zero-sum game | Sulphur plays an important role in the ionization balance in protoplanetary disks and affects planetesimal differentiation, underlining the need to accurately model the chemical evolution of this element from the protostellar to the planetary stage. The sulphur budget in protoplanetary disks is currently poorly known, observations suggest >90% of volatile sulphur is missing from the gas. Chemical models suggest the main volatile S carriers are CS, SO, SO2, and H2S, but in cold disks their gas-phase abundances may be affected by freezeout. We have recently shown how the photospheric abundances of young A-stars trace the composition of their inner disks. For one such star, HD 100546, the S abundance is consistent with all volatile sulphur accreting as gas through the dust-depleted inner disk cavity. We will use ALMA to obtain a spatially resolved census of the main (and a number of secondary) sulphur-bearing molecules in the disk. Comparison of their summed abundances with the stellar S/H ratio will reveal whether there is a need to invoke new volatile sulphur reservoirs, such as a large abundance of sulphur chains. | Disks around high-mass stars | Disks and planet formation | 2018-02-02T15:19:26.000 |
| 949 | 2022.1.01376.S | 17 | Intrinsic-fading OR highly-obscuread: ALMA's clue on X-ray faintness of AGNs in ULIRGs with extreme ionized outflows | Powerful outflows are considered as indicators of AGNs quenching their host galaxies, while recent studies report a puzzling co-existence of extreme ionized outflows and starbursts in eight ULIRGs. More interestingly, NuSTAR X-ray follow-ups for two ULIRGs of them imply declined central AGN engines, suggesting a scenario that the AGNs could quench themselves by strong winds before severely affecting star formation in their hosts. However, since the X-ray flux of the two ULIRGs is extremely faint, it is hard to reliably constrain both of the intrinsic AGN activity and central obscuration only with X-ray observations. In order to break the degeneracy of constraint on intrinsic activity and central obscuration, it is crucial to directly measure the molecular gas mass in the central region (~100 pc scale) using ALMA. With the most powerful ionized outflows and the highest SFR among ULIRGs/AGNs at z < 1, the sample provides a unique laboratory to study the interplay between AGN activity and the circumnuclear materials and to understand how the powerful AGN winds affect star formation in host galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2024-08-31T12:59:55.000 |
| 950 | 2018.1.00994.S | 1154 | CI(1-0) and CO(4-3) survey for nearby ~40 U/LIRGs- Band8 ACA stand alone observation - | We propose CI(2-1) and CO(4-3) observations towards ~40 local ultra/luminous infrared galaxies (U/LIRGs), which are forming stars violently (starburst) and are often observed as interacting galaxies. ULIRGs are the key population to connect the local and high-z Universe. While we have observed CI and high-J CO from galaxies in the early Universe, we have not yet known the information of these lines even in the well studied nearby galaxies. At first we check the consistency between CO and CI based gas mass. Second, we directly connect enormous starburst triggered by a galaxy merger and local physics around the newly born young massive stars. We use the line ratios of the CI(2-1) and CO(4-3) as diagnostics of the photodissociation region (PDR). We look for the evolutionary track along the merger sequence in gas density (n) - UV radiation strength (G0) plane for the first time. In addition, comparing with prior CI observations towards high-z sources, we verify whether the ISM of the galaxies in the early Universe exactly different from local one or not. | Merging and interacting galaxies, Surveys of galaxies | Galaxy evolution | 2020-07-22T05:45:12.000 |
| 951 | 2016.1.00101.S | 196 | Pillars of Destruction: Probing Cloud Destruction and Triggered Star Formation in the Pillars of Carina | Ionised feedback from high-mass stars destroys molecular clouds, removing the reservoir for further star formation and restricting star formation efficiency to a few percent. Irradiated pillars are a key signpost of this process, with simulations suggesting they are either (a) revealed, pre-existing filaments, or (b) formed during cloud destruction via instabilities. Star formation may also be enhanced, suppressed or merely revealed during this process. Despite the importance of these processes to the star formation life cycle they are still poorly constrained, with only one pioneering study (Klaassen et al., 2014) testing the different theoretical pillar formation scenarios via high-resolution observations of the cold gas kinematics in a single pillar. Guided by our proof of concept study, we propose to observe 13 pillar regions in Carina with the ACA to systematically study the effects of feedback. The sample includes pillars with a range of lengths and distances from their ionising sources. These observations will reveal, for the first time, the global gas and dust properties of the pillars and how they vary with radiation field and time. | Outflows, jets and ionized winds, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-05-31T02:03:44.000 |
| 952 | 2019.1.00386.T | 9 | THE EFFECTS OF BURST ACCRETION ON PHYSICAL AND CHEMICAL PROPERTIES OF PROTOPLANETARY DISKS | FU Orionis Objects (FUors) represent the burst phase of the episodic accretion process through protostellar disks, which is considered as the formation mechanism of low mass stars. Therefore, FUors provide an opportunity to study the dynamical evolution of disk structure during outburst. In addition, newly bursting FUors are excellent targets for the study of fresh sublimates, offering a unique and direct probe of the ice composition in the pre-burst (i.e. quiescent) phase. Therefore, in order to study the burst-accretion process and the effect of enhanced heating on disk composition and structure, we propose a ToO observation for a FUor newly confirmed by one of a variety of transient surveys such as Palomar Transient Factory, ASAS-SN, our JCMT/SCUBA2 survey for sub-mm variability, and our IGRINS YSO survey observation. Our proposed observations include lines of CH3OH, 13CH3OH, C17O, H13CO+, HDCO, HDO, CCH, SiO, SO, SO2, and various organic molecules at band 7 with a velocity resolution of 0.2 km/s and a spatial resolution of 0.03" to 0.1", using the earliest available configuration. | Low-mass star formation, Astrochemistry | ISM and star formation | 2022-09-01T06:16:36.000 |
| 953 | 2016.1.00643.S | 36 | High-resolution CO observations of clumpy strongly-lensed galaxies at 0.6<z<1.5 | The aim of this project is to study the resolved properties of the star forming HII regions and giant molecular clouds (GMCs), usually referred as star forming clumps, such as molecular gas mass and kinematics, in typical disc galaxies at 0.6 < z < 1.5. This is an epoch of rapid evolution and a better understanding of the properties of the star-forming clumps could help to constrain the underlying physical processes. To reach the necessary high-resolution and sensitivity, we propose to observe 6 strongly magnified and extremely stretched galaxies, for which numerous ancilary data (HST, SINFONI...) already exist, particularly MUSE observations within the GTO Cluster Lensing program. We aim to target the CO(4--3) line in bands 6 / 7, redshifted at 225.668-286.128~GHz, to probe the CO kinematics and line intensity at a resolution of 0.15". In total, physical properties of 100 individual clumps will be obtained at a physical scale of ~40-700 pc, characteristic of the expected Toomre instability conditions. Combining the sensitivity and resolving power of ALMA with gravitational lensing is so far the only way to reach sub-kiloparsec scale resolution at these redshifts. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2017-10-26T17:37:27.000 |
| 954 | 2012.1.00608.S | 15 | Biased Formation of SMGs in a z=3.1 Protocluster Core | We propose to conduct a 270 GHz (1.1 mm) snapshot survey using ALMA band6 targeted to 45 1.1mm- selected SMGs. Our primary goal is to clarify where SMGs are formed. Although SMGs are supposed to be preferentially formed in mass overdense regions which are observed as protoclusters under the current CDM universe, the observational evidence is still sparse. SSA22 is the best target field of this study since there is a z = 3.1 protocluster and AzTEC/ASTE 1.1mm deep survey have discovered over 100 SMGs toward the protocluster. It has already been indicated that SMGs are concentrated into the core of the protocluster based on multi-wavelength identification and estimation of photometric redshift. The ALMA’s great sensitivity and resolution mean that it should take only 2.7 hours to detect 45 SMGs around the core and resolve them into each component with S/N ≥ 5. The observation will derive an accurate map of SMGs in the protocluster and matching them with photometric redshift search and upcoming optical spectroscopy, allow us to unveil the formation cite of SMGs. Moreover compared the results with z = 3.1 LAEs, we will be able to study how the formation and evolution of galaxies depend on environment in the early universe. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2015-09-22T19:40:04.000 |
| 955 | 2017.1.01214.S | 470 | ALMA Study of the Hyperluminous SMGs Identified from Planck All-Sky Survey | We have identified 31 hyperluminous SMGs with apparent IR luminosity of ~10^14 solar luminosity by selecting candidate high-z sources from the Planck Catalog of Compact Sources and by examining their characteristic dust SED and multi-wavelength photometric properties. They are verified to be high-z sources by detecting 1mm dust continuum and one or more CO lines using the Large Millimeter Telescope. Our ongoing HST/WFC3 imaging program has shown that the majority are strongly lensed SMGs by a foreground massive galaxy or galaxy cluster. Here, we propose to image 16 Planck SMGs using ALMA in the same CO transitions and 1mm continuum detected by the LMT in order: (1) to confirm the AzTEC & RSR detections and to map the location, spatial extent, and kinematics of gas (CO) and and to analyze their relation to SF (1mm continuum) activity and stellar light traced by our HST/WFC3 imaging; (2) to derive the magnification factor and in turn the intrinsic luminosity and masses; and (3) to identify the best candidates for future high resolution, high sensitivity study that will lead to an in-depth exploration of SF and gas physics at 10 to 100 pc scales via gravitational lens modeling. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-04-19T18:16:09.000 |
| 956 | 2019.1.00883.S | 18 | Confirming the First Absorption System against a Quadruply-Lensed QSO | We have serendipitously discovered, a strong millimetre line emitter at 5" from Cloverleaf (a lensed QSO at z = 2.55). Several features (from Herschel and ALMA)indicate that this new galaxy is at z = 2.29, consistent with an intervening absorber against Cloverleaf. SED fitting also allows solutions of z = 5.58, 4.49, and 3.39. Deep HST images at JHK bands show no detections. However, Chandra detected hard X-rays, indicating an AGN-host in a transit stage from starburst to QSO. Here, we apply for an ALMA observation to confirm its redshift by detecting another CO line. With modest observing time (1 hour), this program will allow the first confirmation of an absorbing system that can be spatially resolved with four lenses, and/or study of a unique progenitor of hot dust-obscured galaxy. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2021-04-15T00:00:00.000 |
| 957 | 2021.1.00520.S | 24 | Has Dust Settling Already Started in Embedded Disks? | The timescale for dust settling to occur and how it evolves remains highly debated. Uncertain constraints in dust settling hinders progress for understanding planet formation and disk evolution. This is largely due to the lack of observations that can resolve the dust scale heights in the early stages. Our previous VANDAM Orion ALMA survey discovered an unprecedented number of Class 0/I edge-on disks. We propose follow up observations of 0.03" resolution towards six edge-on sources in order to resolve the vertical height of the disks. In combination with existing data on Class II disks, the measurements of dust heights will constrain when dust settling may happen. If dust settling does not occur in the early stages, then planet formation must be limited mostly to the Class II phase. If dust settling does occur, then planets may develop even in the earliest phases of disks. | Disks around low-mass stars | Disks and planet formation | 2023-01-12T08:51:27.000 |
| 958 | 2016.1.00545.S | 724 | A Complete Demographic Study of the Ophiuchus Disk Population | We propose an unbiased demographic study of the entire disk population (from Class I to Class III) identified by Spitzer in Ophiuchus, the closest of the major star-forming regions near the Sun. We will simultaneously observe 1.3 mm continuum, and the 12CO, 13CO, and C180 J=2-1 lines. We will observe each of the 289 targets for ~1 min and vary the spatial resolution (from 0.25" to 0.6") based on the known or expected 1.3 mm flux. The resulting wealth of data will have a long-lasting legacy value and will be invaluable for both demographic studies and the identification of interesting sources for detailed followup studies. We have designed the the observations based on 3 main scientific goals: 1) derive stellar dynamical masses and assess the dust and gas content of the disks, 2) investigate the diversity of structures in protoplanetary disks to place previous and future results into context, and 3) study the dependence of disk structures on SED Class and stellar properties. The underlying motivation is to perform a complete and unbiased study of a major star-forming region to start making direct connections between disk populations and the populations of planets they may form. | Disks around low-mass stars | Disks and planet formation | 2019-07-17T14:52:44.000 |
| 959 | 2013.1.01207.S | 2 | Constraining H0 with ALMA imaging of the gravitationally lensed quasar RXJ1131-1231 | The tension between previous measurements of the Hubble constant, H0, and that recently derived by the Planck collaboration highlights the need for multiple independent measurements. The tension, if not attributed to systematic effects, would challenge the standard LambdaCDM paradigm. We propose to measure H0 by observing the CO(J=2-1) emission from the spectacular gravitational lens system RXJ1131-1231. By velocity resolving for the first time the CO(J=2-1) emission from the prominent Einstein ring at z=0.658, we will constrain our lens mass models with unprecedented accuracy for cosmography. Specifically, the spatially- and velocity-resolved ALMA images will allow us to measure H0 with an accuracy of ~3-4% from this single gravitational lens system. This is similar in precision to, and completely independent from, the current best measurements from the local distance ladder. Such an independent measurement on H0 based on our proposed ALMA observations is crucial for assessing the current tension between different H0 measurements, which could signal new physics. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2016-08-14T11:41:20.000 |
| 960 | 2018.A.00055.S | 36 | Looking for the CO structure associated to excited molecular hydrogen in molecular clouds | Turbulence in interstellar molecular clouds is thought to play a major role in the conversion of the dense gas into stars, through the dissipation of kinetic energy injected on large scales. Turbulent dissipation is intermittent in nature which implies that it is extremely lacunary, producing small pockets of warm gas within molecular clouds. However, little is known about the structures that are responsible for the dissipation in molecular clouds, which could be shocks or the boundary layers of coherent vortices, or current sheets. Regions of dissipation were pinpointed through the detection of the S(2) line of molecular hydrogen and provide ideal targets to study the structures associated to this dissipation. We propose to use the ACA, in combination with the Total Power array, to perform the first map of the molecular structures associated with excited molecular hydrogen regions. Our proposed maps will enable us to obtain the aspect ratio of the structures, and to compare their orientation with the local magnetic fields lines. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-12-04T00:00:00.000 |
| 961 | 2018.1.00804.S | 975 | Redshifts of bright Herschel gravitational lenses | We propose to continue our successful ACA CO redshift measurements of 30 of the brightest (S500m > 0.1 Jy) strongly gravitationally lensed submm galaxies from the Herschel ATLAS, plus 3 bright ACT mm-wave sources. These simple observations, ideal for the ACA, will double the sample size of H-ATLAS background source redshifts, complementing our long-term 8m-class foreground lens redshift campaigns. Our pioneering lens selection (Negrello et al. 2010 Science) has an astonishing ~100% efficiency and the gravitational amplification makes CO line detection up to ~100× faster than in unlensed surveys. We will provide spectroscopic confirmation of gravitational lensing, by finding submm redshifts that are clearly higher than the redshifts of the lensing masses. This on its own is already enough to make statistical constraints on the dark matter halo profiles. Combined with our ongoing multi-wavelength campaigns, we will start placing direct constraints on the evolving dark matter distribution of the lenses. The joint lenssource redshift distribution is a key discriminator of cosmological parameters and the evolution of dark matter haloes. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2020-02-18T18:16:40.000 |
| 962 | 2018.1.01064.S | 38 | Mapping the Tangled Web of Molecular Filaments in the Turbulent Taffy Bridge | The Taffy galaxies have had most of their gas stripped into a massive bridge by a recent head-on collision. Space-IR observations have shown that the bridge contains warm molecular H2, enhanced [CI] and [CII] emission consistent with shocks and turbulence, and very little star formation. In ALMA Cycle 4, we discovered that the bridge contains a tangled web of peculiar dense CO-emitting filaments that may be transient structures within a large-scale turbulent multi-phase medium. A small subset of the filaments seems associated with star formation (SF), but most do not. Many contain peculiar, nearly unresolved broad-line regions with very short crossing times. We propose to a) perform new high-resolution CO observation to resolve the structures, better understand their dynamics and relationship to SF, b) detect CO 6-5 emission from the filaments to correlate the hot dense (shocked) gas phase with SF sites, and c} detect the dust continuum from the filaments to independantly estimate their possibly huge surface densities. The result will help us understand the potentially important effects of turbulence and shocks on SF suppression or enhancement in the extragalactic universe. | Merging and interacting galaxies | Galaxy evolution | 2020-10-23T18:07:54.000 |
| 963 | 2023.1.00032.S | 0 | The First Cloud-Scale, Dense Gas Maps of the Nearest ALMA-Acccessible Spiral Galaxy | We propose 60pc-resolution observations of 3mm dense gas tracers (N2H+/HCO+/HCN/HNC) in the nearest spiral galaxy accessible to ALMA: M33. N2H+ is a workhorse dense gas tracer in the Milky Way (MW) as it is optically thin and not prone to freezing onto dust grains. However, N2H+ is not readily accessible in observations beyond the MW due to its faintness and low filling factor. In extra-galactic observations, HCN/HNC/HCO+ have been observed at kpc, but cloud-scale (10s of pc) measurements are rare, and how well they agree with results from N2H+ is unknown. With deep observations covering the inner 4kpc of M33, we will hugely increase the number of extra-galactic N2H+ observations, and use these to (a) re-evaluate the dense-gas star formation law with different dense gas tracers; (b) test HCN/HNC as a dense gas tracer in extra-galactic observations, and (c) study the dense gas fraction as a function of cloud evolution, discriminating between density threshold and turbulent models of star formation. These are fundamental and currently open questions and our proposed observations will make key strides in answering them. For these observations, we request a total of 73.32h of 7m time. | Spiral galaxies | Local Universe | 2025-01-26T11:57:34.000 |
| 964 | 2021.1.01014.S | 0 | SO and CCH Zeeman in IRAS 20126+4104: Measuring Magnetic Fields around a High-mass Protostar | Measuring magnetic field strengths around protostars is a crucial part of testing theories of magnetically-driven accretion. While polarization from magnetically-aligned dust grains or the Goldriech-Kylafis effect can trace the magnetic field morphology, the Zeeman effect offers a direct probe of line-of-sight magnetic field strengths. To date, ALMA has not successfully detected the Zeeman effect. To increase the chances of detecting the Zeeman effect, we propose to observe an object whose high accretion rate implies a strong magnetic field: the high-mass protostar IRAS 20126+4104. In addition to its high accretion rate, this protostar stands out as a target due to the presence of a Keplerian disk, a Zeeman-sensitive spectral line, and a previous magnetic field strength measurement with which to compare our magnetic field strengths. We plan to target eight Zeeman-sensitive SO and CCH transitions to measure magnetic field strengths in the disk, outflow cavity, and outflow of IRAS 20126+4104. These observations will test ALMA's capability to directly measure magnetic field strengths and improve our understanding of magnetic accretion in circumstellar disks. | Disks around high-mass stars | Disks and planet formation | 2025-03-22T14:37:02.000 |
| 965 | 2019.2.00235.S | 1085 | A legacy survey of Wolf-Rayet star winds | The powerful and highly ionized winds of Wolf-Rayet (WR) stars emit free-free radiation and recombination lines from the radio to near-IR. Despite being bright at sub-mm wavelengths, few suitable observations have been made in the gap between radio and near-IR wavelengths to characterise the wind properties and compare with models. We propose to use ACA in Bands 3 and 6 (92 and 263GHz) to build a catalogue of mm/sub-mm spectral indices and flux densities of the winds of 57 of the brightest Galactic WR stars. This will be used to identify potential new high-frequency calibration sources for ALMA (to increase the number of phase calibrators available for high frequency bands), investigate statistical trends and compare with wind emission models, and use to select sources and plan future high spatial resolution imaging of the wind morphologies. The catalogue and images will have a strong legacy value to the evolved massive star community. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2021-04-10T21:49:34.000 |
| 966 | 2015.1.00749.S | 68 | Properties of the most distant star-forming GMC in the Milky Way | The properties of molecular clouds and star formation are expected to be subject to Galaxy-scale variations. In the Outer Galaxy, the importance of the spiral structure is thought to be diminished, with a metallicity gradient observed with galactocentric radius. Despite the importance of location in determining the outcome(s) of the ISM life-cycle, these effects are poorly understood. This leaves extrapolation from our current understanding to molecular cloud and star formation properties in even nearby galaxies uncertain, let alone to the conditions under which the bulk of stars in the Universe formed. We propose to comprehensively map and characterise the molecular gas and dust in the most distant star forming region found to date within our Galaxy, where the metallicity is expected to be significantly below that in the Inner Galaxy and supernovae may be more important than spiral arms. With these data, we will constrain the cloud properties (e.g. clump mass efficiency, column density PDF) at comparable resolution to single-dish observations of nearby star forming regions, thus providing the first step in bridging the gap between the Inner Galaxy and the nearby universe. | Outflows, jets and ionized winds, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-05-02T21:26:19.000 |
| 967 | 2019.1.01605.S | 3 | A Comprehensive View of Magnetic Fields around Young Protostars NGC1333 IRAS 4A1 and 4A2 (III) | This is a continuation of our Cycle 2~6 project on the magnetic field measurements toward IRAS4A, where only one of the two science goals (Band 7, 0.2") was observed. Here we propose to finish the other science goal (Band 7, 1") and also add a science goal for extremely high resolution observtion (Band 7, 0.03"). Measuring polarized emission from aligned dust grains remains the most efficient method to probe the structure of the magnetic fields in star-forming regions. Although recent theoretical and simulation work by Kataoka et al. (2015) and Yang et al. (2016a,b) demonstrated that polarization originating from scattering cannot be ignored in the protostellar disks, our multi-wavelength observations show that at Band 7 the polarization is mainly from dust emission/absorption for optically thin/thick cases, respectively. With the current data, we show that it is very feasible to explore the magnetic fields at 10 AU scales (0.03"). If the two science goals requested here are carried out, we will have the most complete picture of magnetic fields at the widest physical ranges that could be observed with ALMA. | High-mass star formation | ISM and star formation | 2023-05-24T00:00:00.000 |
| 968 | 2016.1.00117.S | 61 | FIR [O III] emission from a z ~ 8 candidate galaxy: A glimpse into early production of heavy elements | We propose ALMA Band 7 observations of a secure candidate for a z~8.5 Lyman break galaxy to detect the [O III] 88 micron line. Given the extremely-high brightness of the [O III] line, which has been demonstrated by our recent ALMA detection of the [O III] 88 micron line in a z = 7.2 LyA emitter, the proposed study allows us not only to determine the spectroscopic redshift of the z~8.5 candidate LBG, but also to characterizes metal enrichment for the first time when the age of the Universe was only 600 Myr. The observations will detect 830 micron dust continuum emission even in the case of non-detection of the line, which places a stringent limit on formation process of dust grains in the primordial Universe. ALMA will therefore provide a very unique opportunity before the JWST era that allows a tantalizing glimpse into the earliest production of heavy elements. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2018-06-07T00:00:00.000 |
| 969 | 2023.1.01245.S | 48 | Outflow matching to contemporary accretion in PBRSs | Fluctuations in protostellar outflows, especially SiO knots, are postulated to represent a fossil record of the episodic accretion history of protostars. Yet, detection of a subsequent increase in low-mass protostellar outflow activity following a luminosity burst has not yet been corroborated. Given recent and on-going years-long all-sky NEOWISE mid-IR monitoring of accretion variability onto protostars, ALMA is now poised to finally confirm this fundamental assumption. We propose to use ALMA to perform deep observations in both outflow- and jet-tracing molecules to investigate the freshly ejected material around 3 PACS Bright Red Sources (PBRSs), potentially the youngest protostars in Orion. Matching the properties of the ejecta with the directly detected and recent accretion history will significantly aid determinations of how much mass is accreted onto the protostar versus dispersed away from the system. | Outflows, jets and ionized winds | ISM and star formation | 2024-10-05T19:36:02.000 |
| 970 | 2013.1.00358.S | 16 | Testing the Dark-Matter-Halo Paradigm | The use of gravitational lenses as a tool for cosmology has been limited by the small sizes of samples of lenses, but the discovery that most bright submillimetre sources are lensed is on the verge of revolutionising this field. We propose to obtain ALMA observations of 42 bright Herschel lensed sources for which we already have redshifts. We will use the ALMA maps to determine the density distribution around each lens and to reconstruct the unlensed source emission. We will use the results to make an immediate test of the theoretical predictions of the mass function of dark-matter halos, on which all current models of galaxy and cluster evolution are based. Since the reconstructed images of the source emission will have a physical resolution of ~200 pc, only twice the size of a giant molecular cloud, we will also obtain a superbly detailed picture of a large sample of ULIRGs at an epoch when the average star-formation rate was at its peak. Finally, we will also use the dataset to investigate separately the evolution of the dark matter and baryons at the centre of the halos. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2016-10-25T19:03:23.000 |
| 971 | 2018.1.01635.S | 16 | Late follow-up of the unique GRB171205A | GRBs are powered by compact objects that eject matter at ultra-relativistic velocities. This makes them ideal laboratories to study radiation processes in extreme conditions. Swift has detected >1000 GRB afterglows but only 20-30 were bright enough for extensive follow-up from radio to X-ray wavelengths to provide crucial constraints on the radiation processes. GRB171205A was a unique event, being the 4th closest long GRB to date and the second brightest in millimeter wavelengths. We have already started an extensive observing campaign between 600 MHz and X-rays. For the first time we have the opportunity to follow an event in millimeter wavelegths for over a year and explore the late deceleration of the afterglow and the transition to a non-relativistic phase. Combining data over a very long time in multiple frequencies will allow us to accurately measure the energetics of the event, precisely test the models, and characterise any non-standard radiation components. This is a short and easy to execute programme with only two continuum observations in Band 3. | Gamma Ray Bursts (GRB) | Cosmology | 2019-10-21T12:34:59.000 |
| 972 | 2017.1.01404.S | 0 | Disk-planet interaction in a nearby young system | Transition Disks are thought to be prime candidates of disks hosting young planets, mostly based on indirect evidence. Planets have been found by direct imaging in a few cases. Finding planets and studying disk-planet interaction is critical to understand planet formation and disk dispersal. By means of high contrast infrared imaging, we detected direct evidence for a planetary mass companion inside the cavity of a nearby transition disk and of its interaction with the disks. The available ALMA observations show some tantalizing evidence for disk disturbance, but do not have sufficient angular resolution to really resolve the structures, confirm their connection with the planet candidate and put constraints on the filtration of material from the outer disk to the planet and the potential presence of a circumplanetary disk. This proposal aims at resolving the structures in the disk induced by the interaction with the planet and to detect (or put strong limits) on the amount of circumplanetary material. These will provide an observational benchmark to numerical models of disk-planet interaction and planet formation. | Exo-planets | Disks and planet formation | 2018-12-14T22:41:18.000 |
| 973 | 2016.1.00922.S | 15 | ALMA Observations of the Nearest Tidal Disruption Event | We propose an ALMA follow-up observation of the nearest tidal disruption event (TDE). This event, detected initially by Integral in the X-rays and later by JVLA, is believed to be due to the disruption of a super-Jupiter by the central supermassive black hole of NGC 4845 (d=17 Mpc). Its proximity offers us a so far unique close-up of the TDE and its aftermath. New VLBA} and JVLA observations, obtained in 2015, show that the radio flux has decayed in a manner consistent with predictions. But more excitingly, they also contain evidence of ejecta, in the form of a resolved component located 52 milliarcsec (4.1 pc) from the nucleus which, if ejected in 2010 as a result at the TDE, is moving superluminally at 2.4c. The ALMA continuum observations, in conjunction with additional HST and VLBA observations (being proposed this year) will allow us to obtain a more detailed picture of the decaying TDEs spectral energy distribution, probing the ongoing particle acceleration. We will also look for line emission which, in combination with the HST data, will help us to gauge the impact on NGC 4845's nuclear regions. | Spiral galaxies, Galactic centres/nuclei | Local Universe | 2018-01-13T02:08:47.000 |
| 974 | 2022.1.00322.S | 7 | Unveiling the nature of a strong H2O absorption in a dusty galaxy at z=4.1 | Recently, a strong ortho-H2O absorption in a z=6.4 galaxy was interpreted as an impact of CMB (Cosmic Microwave Background) by Riechers et al. 2022, and was used to constrain the CMB temperature at z=6.4. Notably, Riecher et al. 2022 concluded that the absorption against the CMB is not detectable at z<5. Nevertheless, we have found a similarly strong H2O absorption in a z=4.1 galaxy with an absorption peak penetrating to negative, which the negative flux is lower than the prediction of Riecher et al. models by 4 orders of magnitude. It is unclear where the huge discrepancy comes from. Outflow+CMB impact is a possible solution to the strong H2O absorption at z=4.1, but this is highly unsure due to the noisy line profile. We propose deep ALMA observation to solidly confirm this absorption with high quality line profile, unveiling the physical structure of the ISM and the possible CMB impact. | Sub-mm Galaxies (SMG), Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE) | Galaxy evolution | 2024-04-10T21:15:40.000 |
| 975 | 2019.1.00414.S | 28 | Resolving Structures of Young Protoplanetary Disks | Small scale structures such as rings and gaps are important indicators of on-going planet formation. Recent surveys of Class II objects indicate that small scale substructures such as rings and gaps are abundant. The next natural step is to explore whether such structures are present at younger ages. For Class I objects, several disks are found to harbor such structures, while most disks remain unresolved due to small sizes, as revealed by surveys at ~0.2asec resolution. Therefore, it is necessary to perform high spatial resolution survey of young disks. We propose to observe 11 Class 0/I or Flat Spectrum objects in Ophiuchus region at 0.02-0.04 arcsec resolution. We selected targets based on archival ALMA data and our recent ALMA spectral index survey. Most disks show spectral index of ~2 and the size of <0.3asec, indicating that either grain growth has already taken place or optically thick disks with substructures are present, making the beam filling factor low for low-resolution observations. Our program will unambiguously distinguish these possibilities and provide novel insights into planet formation processes at the early phase of disk evolution. | Disks around low-mass stars | Disks and planet formation | 2022-08-06T20:20:51.000 |
| 976 | 2023.1.00895.S | 0 | Cold molecular gas in an active and massive protocluster environment at z=4.3 | SPT2349-56 is one of the most iconic IR bright protoclusters discovered so far in the early universe, possessing the highest star fomation rate density observed in protocluster systems, and amongst the largest halo masses ever observed directly at z>4. So far, 30 gas-rich members have been identified, two merging halos, a large gas filament surrounding a forming brightest core galaxy and an associated Ly-alpha blob at its core. However, we still have not been able to measure the demographics of the cold molecular gas fueling the intense star formation activity and the massive gas filament. Here, we propose to conduct deep CO(2-1) imaging of this system to pinpoint the cold molecular gas from individual sources. This will allow us to (i) measure the gas masses, star-forming efficiencies, and molecular gas fractions, (ii) estimate ISM excitation conditions based on the ratios between the [CII] and CO(J>4) lines to CO(2-1), (iii) conduct blind line searches of low ISM excitation galaxies, and (iv) study the observed formation of an extended [CII] arc at its core. The proposed observations will provide a key pivot for fully characterizing this unique system. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-08-01T16:37:08.000 |
| 977 | 2015.1.00686.S | 1 | Characterizing Substructure in the TW Hya Disk | Theoretical models for the early stages of planet formation make predictions for the evolution of solids in protoplanetary disks that conflict with resolved mm-wavelength data. Calculations of inward migration rates for mm/cm-sized particles are much too high to account for the extended emission that is routinely observed. The nominal solution for this problem is to invoke small-scale substructure in the disk, which can trap particles in local concentrations. Such inhomogeneities may be caused by embedded planets, magnetic structures, hydrodynamic instabilities, or turbulent fluctuations. In any case, this substructure is absolutely fundamental to the planet formation process. We propose sensitive, very high angular resolution Band 7 continuum observations to find and characterize this substructure in the closest protoplanetary disk, around TW Hya. This disk is the only case where we can resolve low-amplitude features as small as 2 AU, sufficient to measure planetary gaps on scales compatible with our Solar System architecture and to probe turbulent fluctuations with sizes comparable to the gas pressure scale height over most of the disk volume. | Disks around low-mass stars | Disks and planet formation | 2017-01-16T01:07:11.000 |
| 978 | 2011.0.00294.S | 0 | More than LESS: The first fully-identified submillimetre survey | Ultraluminous infrared galaxies, specifically submillimetre-selected galaxies - SMGs, are a significant class of star-forming galaxies at z>1. There are a few thousand SMGs known, but no sample has the complete, secure identifications needed to derive their basic properties. We propose compact Band 7 continuum observations to precisely locate the submillimetre-emitting components in a complete sample of 126 SMGs selected from the recent LABOCA survey of the ECDFS. These observations will pin-point the submillimetre-luminous components within these sources, without recourse to statistical associations using radio/mid-/far-infrared counterparts. ALMA will thus address two key shortcomings of current submillimetre surveys: (1) Source blending - many SMGs are expected to be blended at the resolution of their discover maps. To determine the true form of the submillimetre counts - a key observable constraint of theoretical galaxy formation models - we need ALMA-resolution maps of a large sample of SMGs. (2) Incomplete identifications - the radio/mid-/far-infrared data miss the most distant (and coolest) SMGs due to their K-corrections, this biases the derived redshift distribution. ALMA will identify all the SMG counterparts in the same band they were selected in, irrespective of their redshift/spectral properties, testing the validity of the radio/mid-/far-infrared identifications (when present) and uncovering the high-redshift tail of SMGs. The improved resolution of the ALMA maps will also show the relation between obscured starburst and unobscured stellar mass and AGN activity within these systems. These 5.4-hrs of observations will provide revolutionary science - addressing fundamental questions about the nature of SMGs - in a way which was impossible before ALMA. | Sub-mm Galaxies (SMG), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2013-02-15T13:06:05.000 |
| 979 | 2022.1.01346.S | 0 | Characterizing the magnetic field morphology at the launching points of a protostellar jet | Serpens Emb 8(N) is a Class 0 protostar that drives an extremely high velocity, highly collimated bipolar molecular jet. Previous ALMA data observations of dust polarization toward the core revealed an organized magnetic field aligned along the dusty outflow cavity walls, where the polarization is enhanced. Low angular resolution, Band 6 CO observations strongly correlates with the observed magnetic field, with field lines perfectly aligned along the edges of the extremely high velocity molecular jet, which make this core a very interesting target to investigate the role played by the magnetic field in the launching of molecular jets and outflows at the youngest stage of protostellar evolution. We therefore propose to map the magnetic field at 35 au resolution in the outflow and in the inner core of the protostar in order to compare the detected field morphologies with those predicted by models of jet launching. The expected morphologies are an helical field in the outflow and a poloidal field in the inner core. We will thus address long-standing questions of how the magnetic field is driving the ejection of protostellar jets. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2024-12-12T18:32:21.000 |
| 980 | 2023.1.00124.S | 0 | Assembling the first intra-cluster medium: SPT2459-56 at z=4.3 | We propose a high-risk but very high-reward proposal to search for the intra-cluster medium (ICM) via the thermal SZ-effect in an extremely massive proto-cluster at z=4.31. ALMA observations show SPT2349-56 contains 30 dusty, intensely star forming dusty galaxies within 100~kpc radius (total SFR~10,000 Msun/yr), with a bound dynamical mass of M200 ~ 10^13 Msun and a Coma-like descendant by z=0. This structure presents a unique opportunity to study the formation of the ICM, two Gyr earlier than any SZ or X-ray detected cluster, when processes that heat the ICM and establish the central entropy should be operating. A first detection of the forming high-z ICM is within reach of deep ALMA data, through 25hrs of compact configuration time at 93GHz, with the C-1/C-2 configs 3.6" beam well matched to the expected 8" size of the compact tSZ signal. Modelling and removing the emissive SMG sources can be achieved with archival and the proposed data itself. The band-3 data will also have a legacy value in ultra-deep constraints on the diffuse CO(4-3) gas in the core. This will enable a path finding science benchmark for Simons Observatory, and CMB-S4 to search for distant cluster SZ. | Sub-mm Galaxies (SMG), Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE) | Galaxy evolution | 2025-06-04T19:14:48.000 |
| 981 | 2015.1.01290.S | 7 | Mass accretion in the central pc-scale of NGC 1052 | We propose high-resolution imaging of molecular (CO, HCO+, HCN) and ionized (H26 alpha and H30 alpha) gas, dust and bremsstrahlung continuum toward the radio galaxy NGC 1052 to quest mass accretion process onto the central engine. This is a long-baseline extension of the Cycle-2 project (2013.1.01225.S, grade B), with better resolutions of 3 pc. Our goals are to (1) clarify gas distribution and velocity fields in the circumnuclear region, and (2) unveil the structure of dust and plasma torus. Combined with VLBI and Cycle-2 results, we shall illustrate inflow stream from the galactic disk to the central engine. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-02-05T11:09:24.000 |
| 982 | 2017.1.00678.S | 350 | Evolution of outflow-envelope interactions in low-mass protostars | We propose Band 6 ALMA observations to study the evolution of the outflow-envelope interaction using a sample of 21 protostars at different evolutionary stages in the Orion A molecular cloud. We will conduct multi-line observations of the environment around these protostars that will allow us to trace the distribution of the outflowing gas (and its momentum and kinetic energy) with respect to the kinematics and structure of the infalling envelope. We will map each source with a (12m array) 7-point mosaic and the ACA to obtain data with a resolution of about 450 AU and sensitive to structures extending up to about 0.1 pc scales perfect for studying the properties of the envelope. With these observations we aim to: 1) determine the importance of outflows in the removal of dense gas surrounding protostars and its effect on the core-to-star efficiency; 2) establish how infall and outflow rates change of over the lifetime of prototstars and understand the relative effect of infall and outflow at different evolutionary stages on a cores mass loss process; and 3) use the results to develop an empirical model of the evolution of the mass-assembling process of low-mass protostars. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-12-10T18:09:58.000 |
| 983 | 2017.1.00653.S | 4 | Heating of the quiet Sun chromosphere by two contrasting mechanisms | We propose to conduct a comprehensive search for the heating of the quiet Sun chromosphere at Bands 3 and 6 in coordination with optical, UV, EUV, soft X-ray, and hard X-ray observations. Our aim is to detect, for the first time in the same dataset, both transient bright features indicative of shocks that form as magneto-acoustic waves propagate in the chromosphere, and small-scale flare-like brightenings indicative of magnetic reconnection. The primary diagnostic to distinguish them will be their different temporal characteristics. We will compare the occurrence rates of the two types of heating events, and we will also compare their properties with those of similar events that will be detected by the instruments that will be co-observing with ALMA. These will be the first necessary steps to address the question on how often, when, and where different heating mechanisms take place. | The Sun | Sun | 2019-08-09T17:25:09.000 |
| 984 | 2017.A.00014.S | 0 | Is there a planet in the dust gap around CI Tau? | The aim of this proposal is to discover whether a massive planet is responsible for the gap in continuum emission at 12 AU in the disc around the T Tauri star CI Tau which has been revealed in our recently received Cycle 4 data. CI Tau is the only disc bearing star to date in which there is evidence for a hot Jupiter (discovered by radial velocity methods at ~0.1AU). Given the established association in mature exoplanetary systems between hot Jupiters and gas giant planets between 1-20AU, it is evidently of great interest to discover if this gap can be interpreted as a planet. Our modeling of our Cycle 4 data implies that if this gap derives from a planet, then it must be massive (~3 Jupiter mass) and would thus also produce a deep gap in the gas at this radius. On the other hand, 12AU is close to the CO snowline in this system so it is also possible that the gap represents an opacity gap due to the absence of large grains. We have simulated both scenarios and show that our proposed CO isotopologues imaging would allow us to prove or disprove the planetary hypothesis. If confirmed, CI Tau would be the first young star with a characterised planetary system architecture within 20 AU. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2018-08-21T20:42:27.000 |
| 985 | 2021.1.01247.S | 3 | Joint ALMA and CO Observations | Prior solar observations with ALMA have revealed surprising dark patches, or holes, in the 3 and 1.25 mm continua. These results have been compared to similar CO absorption features in Sun, although a link between these phenomena has not been observationally confirmed. We propose joint observations in ALMA Bands 6 and 7 (which are expected to form in the low chromosphere and temperature minimum, respectively) with measurements of the fundamental band of CO at 4.7 um by the Cryogenic Solar Spectrograph (CYRA) at the Goode Solar Telescope. By comparing these diagnostics, we hope to understand the temperature variations of the middle solar atmosphere. We will execute mosaics of approximately 25x75 of both a magnetically active and a quiet region in each wavelength band. We will perform spatial and temporal comparisons of features scene in the two datasets, directly or statistically as needed. We will also perform iversions of the ALMA continua together with UV spectra from the Interface Region Imaging Spectrograph (IRIS) to reconstruct the temperature profiles throughout the atmosphere. | The Sun | Sun | 2024-12-01T14:42:54.000 |
| 986 | 2017.1.00286.S | 97 | Search for Possible Disk-scale Asymmetric Structures in Protoplanetary Disks | Some protoplanetary disks show asymmetric structures that may be deeply connected to planet formation. It is important to know what kind of structures are common, and how they are connected to physical processes. To achieve this goal, we need a large sample of disks resolved with high spatial resolution. High resolution observations are sometimes time consuming, and target selection processes are critical. We have developed a novel, efficient method of finding large scale asymmetric structures "hidden" in low-resolution images. We conducted an archival search and found several tens of targets that deserve high resolution follow-up observations. In this proposal, we pick up three relatively bright sources, as a pilot study for future large scale survey. We aim to find any asymmetric structures and establish the best observing strategy in future. Our targets turn out to show other evidences of asymmetry, such as stellar multiplicity, high disk mass, and/or high accretion rate. Investigation of individual targets and comparison within the targets will provide valuable information about protoplanetary disks in various environment, even with this pilot study of three objects. | Disks around low-mass stars | Disks and planet formation | 2019-02-22T01:01:25.000 |
| 987 | 2013.1.00280.S | 50 | Molecules in supernova 1987A - chemistry, nucleosynthesis and gas dynamics | Supernovae (SNe) are the main source of chemical enrichment in galaxies. SN 1987A was the nearest SN explosion detected in 400 years. Since its discovery, SN 1987A has given us remarkable insights into the physics and chemistry of SNe. Our ALMA Cycle-0 detected molecular line emission in the SN ejecta, thus opened up an exciting new avenue of observational research, molecular astronomy in SNe. In this cycle-2 programme we propose an unbiased line survey of SN 1987A from 210 to 350 GHz. We aim to detect new species of molecules that have been predicted to form in SN ejecta, and to measure the emission from the isotopologues of these molecules, as well as their velocity profiles, densities and temperatures. Measurements of molecular isotopologue ratios will allow us to measure isotope ratios of C, O, S, Si. This will provide direct constraints on stellar yields from SN nuclosynthesis. These measurements of abundances for species other than CO and SiO will constrain not only chemical models. We will also measure the line profiles from different molecular species, tracing turbulent structure that resulted from the hydrodynamical instabilities caused by the SN explosion. | Supernovae (SN) ejecta | Stars and stellar evolution | 2015-11-12T15:27:22.000 |
| 988 | 2016.1.00012.S | 17 | Extended Star Formation in the Brightest Unlensed Submillimeter Galaxies | Distant SMGs represent the most massive of the young galaxies rapidly building up their mass in the early universe. Their importance in terms of understanding the cosmic stellar mass build-up history is amplified if they represent the pinnacle of the "cosmic downsizing" phenomenon. We have obtained 345GHz continuum images at 0.02" resolution toward three unlensed submillimeter galaxies during cycle 3 of ALMA, with a primary science goal to investigate the detailed spatial distributions of dust in the intrinsically most luminous SMGs as a direct test of how such extreme starbursts can be fueled and sustained. We found that the morphology of dust in the central kpc is highly complex with extreme star formation properties that are comparable to (or exceeding) the Eddington limit for starbursts. We have also found that the amount of missing flux is extremely high (70-85%) compared to lower resolution SMA images, which suggests that the bulk of the star formation is in fact taking place in the extended disk. Here we propose 4 hours of Cycle 4 time in the C40-5 configuration to recover this missing flux and to properly image the dusty star formation activity beyond the central kpc. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-02-04T03:58:42.000 |
| 989 | 2021.1.01112.S | 10 | Gas kinematics and feedback process in a strongly lensed SMG at z=6.03 | It has been recognized that submillimeter bright galaxies (SMGs) are likely the progenitors of massive elliptical galaxies in the present Universe, but little is known about how SMGs evolved. This proposal requests 1.3 hours of ALMA time to investigate the gas kinematics and the feedback process in a strongly lensed SMG at z=6.03. We plan to observe [CII] 158um far-infrared fine-structure lines (Band 6) with high angular resolution (0.3"). The main significances of this proposal are as follows. (1) The kinematics data of the highest-z SMG will be obtained. Since kinematics reflects the process of galaxy formation, such as mergers and cold stream, studying kinematics of SMG leads to studying how massive elliptical galaxies formed. (2) The properties of [CII] outflows and the efficiency of the associated feedback will be investigated. The proposed study will provide an important clue to the questions about what drives starbursts and how much feedback processes influence quenching, which are the major problems in the field of galaxy evolution. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2023-06-30T06:18:50.000 |
| 990 | 2013.1.01267.S | 2 | Using ALMA to look into galaxy cluster cool cores at high-z | We propose to demonstrate that high-resolution Sunyaev-Zel'dovich (SZ) effect imaging with ALMA can provide a major step forward towards measuring the core temperatures of high-redshift (z > 1) clusters. Together with short-baseline SZ data from the ACA, and Chandra X-ray surface brightness images with moderate (< 100 ks) exposure, the temperature profile of even high-z clusters can be efficiently modeled down to their central ~ 50 kpc radius, thereby overcoming a major observational bottleneck in galaxy cluster research. To demonstrate this, we propose ALMA + ACA observation of the z=1.39 massive galaxy cluster XMMU J2235.3--2257 at 100 GHz. By combining with the existing Chandra X-ray imaging data, we shall be able to reconstruct the radial temperature profile for this well-studied system for the first time, putting precise constraints on its core temperature and entropy. This will be the highest redshift cluster to-date with a temperature profile measurement, and only the second such result for a z > ~1 cluster. We expect that joint SZ/X-ray modeling with ALMA will open up an efficient window for understanding the assembly history of baryons in clusters at high redshifts. | Galaxy Clusters | Cosmology | 2016-08-31T00:00:00.000 |
| 991 | 2012.1.00762.S | 1 | Extended GMC survey in the nearby galaxy M83 | Molecular-rich galaxies with prominent galactic structures are the most suitable targets for the investigation of the evolution of giant molecular clouds (GMCs, size ~40pc) which lead massive star formation. However, due to the limited mapping ability of the existing telescopes, observations toward such molecular-rich galactic disks were limited with coarse resolutions (over 200pc), up to recent. Our recent pilot studies made with GMC-scale resolutions have revealed an evolutionary sequence of GMCs and implied that one of the necessary conditions for GMCs to initiate massive star formation is virialization of the natal GMCs on global scale, despite star formation is a sub-pc scale phenomena. However, these previous studies were made with small survey area and target area were biased around massive giant molecular associations (GMAs). To robustly verify the findings and make further constraints, we propose wide-field observations of the nearby barred galaxy M83 in CO(1--0) with a significantly larger mapping area compared to the previous studies. Proximity of the galaxy, presence of prominent galactic structures, and accessibility from the ALMA site make this galaxy most suitable for our purpose. With the proposed GMC survey, hundreds of GMCs will be detected with sufficient S/N ratio (>10). Identified GMCs will be compared with the existing multiwavelength data-sets to find associated HII regions and star clusters, and to robustly state their evolutionary stage. By comparing the properties of identified clouds which reside in a variety of evolutionary stages and galactic environments, conditions required for the onset of massive star formation will be extensively verified and further constrained. Finally, we must note that this proposal is an extension of the previous Cycle 0 project (2011.0.00772.S). However, no observational data is delivered yet and status of observation is also unknown. As we consider this project is urgently important in that the GMC survey data will serve as a reference to all other projects which target on GMCs, we decided to submit this Cycle 1 proposal which shares almost the same science goal with the previous Cycle 0 project. We would like to emphasize that although nearly half of the target area is identical to the previous proposal, inclusion of ACA should raise archival value of the data and would be of public interest, as the previous Cycle 0 project intended to recover missing flux by combining with our own single dish data. Moreover, Cycle 1 capability enable much reliable imaging by improved (u,v) coverage. Increased sensitivity enable to double the survey area and thus increase the number of GMC samples. This is also important in that it enables to cover wider range of environments. Spatial resolution is also improved (~50pc to ~40pc) and thus resolution bias will be reduced. All these points favor our study in that statistical reliability will be furthermore increased. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2016-05-12T00:58:46.000 |
| 992 | 2021.1.00267.S | 5 | ALMA band-7 survey in the HUDF: Slicing the properties of the faintest dusty galaxies through cosmic time | One of the most important results of the deep field mm continuum surveys in the Hubble Ultra Deep Field (HUDF) has been the measurement of an unexpected but clear flattening of the cumulative 1.2-mm continuum number counts at faint flux levels (<0.1 mJy). This implies that most of the cosmic cold dust reservoirs are finally being accounted, with most of the galaxies located at z<3. Here, we aim to capitalize on these findings, by obtaining a deep 870um dust continuum map over the HUDF down to an rms of 45uJy. Aside from having a unparalleled legacy value, these observations will (1) measure the faint-end slope of the number counts independently at 870um, providing insights on the reasons behind this flattening (are faint galaxies just dust poor? differences in metallicities?); (2) study the dust properties of individually detected galaxies; (3) provide an independent estimate of the dust-obscured cosmic SFR density, which can be compared to cosmic molecular gas density estimates; (4) Provide constraints on the dust temperatures at z>3 through stacking, informing IRX-beta/stellar mass relationships. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-04-21T13:58:16.000 |
| 993 | 2016.1.01100.S | 43 | Resolved thermal images of Pluto and Charon | We will use ALMA in configuration C40-9 at 1.1 mm to obtain spatially resolved images of Pluto and Charon individually at thermal wavelengths. ALMA is unique in its ability to produce such images, which will be very powerful tools in understanding the surfaces of Pluto and Charon. Accurate measurements of thermal parameters like emissivity, thermal inertia, and the distribution of surface temperatures will aid in modeling the volatile transport on Pluto, which is key to understanding the evolution of its surface and atmosphere over time. With the recent flyby of New Horizons, we know much more than we did previously about both bodies, but the proposed observations still add unique information which will help understand the two. Data from NH will be critical in our modeling of the thermal emission, and our data will be important in interpreting some NH observations (temperature, albedo, 4.2-cm brightness temperature, etc.). A particular example is the apparent lack of N2 ice/frost in the north polar regions from NH, despite it being predicted to be there by some models. ALMA measurements will be able to resolve the north polar region, and help disentangle this problem. | Solar system - Planetary surfaces, Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2018-11-09T18:46:34.000 |
| 994 | 2022.1.00995.S | 5 | Dissecting Cavity, Bar, and Spirals in A Massive Protostellar Disk | Accretion disks around early O-type protostars are critical in transporting mass to protostars and forming close binaries through fragmentation. We propose ALMA longest baseline observations to study a unique massive protostellar disk with remarkable spirals connected to a bar-like structure at the center. We aim to resolve the bar-like structure that has never been seen in any other protostellar disks in O stars, to detect a possible central cavity created by dust sublimation and photoevaporation, and to search for companions formed out of fragmentation of the spirals. The results will have significant implications on several aspects of massive star formation, including massive disk evolution, the bloated-up stage of protostellar evolution, photoevaporation and dust sublimation, and binary formation through disk fragmentation. | High-mass star formation | ISM and star formation | 2024-09-26T22:11:20.000 |
| 995 | 2015.1.00928.S | 22 | Ionized and Neutral ISM Properties in "Normal" vs. Starburst Galaxies at z=5-6 | Using the unprecedented sensitivity of ALMA, we have recently detected strong [CII] emission in the first significant sample of "typical" star-forming galaxies at z=5-6. These results indicate that typical galaxies ~1 Gyr after the Big Bang appear to have low dust content, but they contain significant amounts of gas, at perhaps low metallicity. This contrasts findings for massive starbursts at the same epochs, indicating a strong evolution of the ISM in typical galaxies between redshift 3 and 6. To investigate the properties of the ISM at such early epochs, we here propose to observe the [NII] 205um line towards three galaxies in our sample at z=5.3-5.7, spanning a factor of ~100 in star formation rate (including normal, Lyman-break galaxies, and the most distant unlensed starburst known). This will allow us to measure, for the first time, the ionized gas content and the neutral gas fraction contribution to the [CII] emission at such high redshift. We will be able to investigate if these properties change significantly with dust content and the level of star formation activity, providing critical insight into the processes that govern stellar mass assembly in the early universe. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-01-28T18:40:35.000 |
| 996 | 2023.1.00713.S | 0 | The spatial distribution and gas kinematics traced by multiple ISM diagnostics in a quasar-starburst system at z = 6 | We propose ALMA multi-band observations of multi-CO transitions and [O I]146um line and the dust continuum emission toward the quasar-starburst system J2310+1855 at z = 6.0031 at identical sensitivity and resolution of 0.2". The proposed lines are well studied with ALMA low-resolution observations, however the spatially resolved gas/dust properties and gas kinematics traced by multi-phase ISM is still unknown. With the proposed high-resolution ALMA observations (1) we will compare the spacial distribution and the extent among different ISM tracers, simulation results, and across the cosmic time. (2) we will study resolved [O I]-FIR deficit to find the nature of the reduced [O I], and resolved Kennicutt-Schmidt relation to determine whether the star formation law for this target have any deviations. (3) With image decomposition, we are able to investigate the heating mechanism (star formation and/or AGN) of the ISM. (4) We will investigate the kinematic properties (e.g., rotation velocity, gas velocity dispersion, gas disk inclination and position angle) traced by different ISM diagnostics with identical resolution and sensitivity. | Galaxy structure & evolution | Galaxy evolution | 2024-12-07T01:12:19.000 |
| 997 | 2016.A.00010.S | 2 | Cometary out-gassing or icy planetesimal collision in a young debris disk? | There is a pivotal point in the lifetime of circumstellar disks at the 5-10 Myr mark: the transition between gas-rich proto-planetary disks towards gas-poor debris disks. It is thought that planets must be formed before (giant planets) or shortly after (rocky planets) this critical phase, and yet the details of how this transition proceeds is poorly constrained. A key observable to better understand this short-lived phase is the detection and characterization of gas in young debris disks, as we can learn about the formation and evolution of icy planetesimals and cometary bodies. We detected the CO 6-5 emission line in the 10 Myr old debris disk around HR4796, using APEX. This unique high transition detection for a debris disk is even more interesting as the line appears blue-shifted without a red counter-part, suggesting an asymmetric distribution of the gas. We propose ALMA Band 9 observations (C40-3), as the unmatched spatial resolution will enable us to constrain the kinematics of the gas. With these new observations, we could reveal on-going cometary out-gassing in the inner regions of the disk, or collisions of icy planetesimals in the debris disk at about 1". | Debris disks | Disks and planet formation | 2018-01-28T10:42:05.000 |
| 998 | 2018.1.00105.S | 15 | Magnetic Fields in High-Mass Star Formation | [This is a re-submission of a previously approved B-rank proposal (2017.1.00101.S) from cycle 5. No data delivery by the time of submission, if the data are still delivered, this proposal will be obsolete.] Polarization observations are finally feasible for large samples, allowing to reveal their importance in high-mass star formation. For the first time, we aim to carry out a complete picture of the energy balance of high-mass star-forming regions at the scales directly related to the star-forming process (500-1,000 AU). By observing 31 high-mass star-forming regions, containing >60 cores, we will determine: i) what is the relative balance between turbulence, gravity, and magnetic fields? is this balance universal or variable? ii) and, with the help of numerical simulations, what control the different fragmentation scenarios observed in our sample. We have assembled a strong team for such a large program, including experts in ALMA data, polarization observations, and numerical simulations. | High-mass star formation | ISM and star formation | 2022-12-20T00:00:00.000 |
| 999 | 2013.1.00710.S | 52 | Constraining the Episodic Accretion of Protostars | The traditional picture of building stars by the steady disk accretion is challenged by results from the Spitzer ``Cores to Disks" survey. The episodic accretion of protostellar disks has been proposed, which may revolutionize our understanding of various aspects of star and planet formation. The most dramatic episodic accretion events in YSOs are FU Orionis and EXor outbursts. In order to understand the outburst mechanisms, we propose to carry out a band-6 survey of nearby FU Orionis (3 targets) and EXOr objects (5 targets) in Orion with 0.2” resolution to measure the gaseous disk mass (from the 13CO and C18O line intensities) and the dust continuum structure. All 8 objects are within 10 deg of each other in the sky and can share phase calibrators. The program can thus be completed in only 1.6 hs. | Low-mass star formation | ISM and star formation | 2016-11-19T23:36:27.000 |
| 1000 | 2019.2.00028.S | 543 | A Representative Interferometric Survey of Galaxies in the z=0 Universe with Full IFU Spectroscopic Coverage: EDGE | Spatially-resolved studies in the optical and mm-wave bands are crucial to connect the local physics to the global trends observed in galaxies, and anchor our physical understanding of the processes that shape them. What is sorely needed is such a survey over a galaxy sample that is representative of the local population, with depth capable of producing statistically meaningful results, and at a resolution that can be directly compared to cosmological simulations. We propose ACA CO 2-1 observations of 145 galaxies selected from the CALIFA IFU sample, to produce a statistically meaningful dataset free of cosmic variance and inform galaxy evolution science in the coming years. CALIFA provides the best z=0 IFU sample for resolved molecular gas studies: its galaxies are nearer and better resolved than in MaNGA or SAMI, it is representative of the population for log(M*/Msun)=10-11.5, and it provides excellent data on all key optical transitions. With these observations we will answer fundamental questions in galaxy growth and aging, star formation regulation, the structure of the molecular component, and produce a lasting legacy dataset for the z=0 universe. | Surveys of galaxies | Galaxy evolution | 2022-11-10T18:40:21.000 |
| 1001 | 2018.1.00606.S | 85 | Verifying the nature of the blazar cores : the case of CTA 102 | We propose to observe the blazer CTA 102 for total 4 hours at band 4, 5, 6 and 7 to study the bright, upstream, and compact region called 'core' and its magnetic field. Since the core is thought to be optically thick-thin transition due to synchrotron self-absorption(SSA) at cm region, the Faraday rotation measure (RM) is expected to increase as a function of frequency; the higher the observing frequency is, the more the EVPA rotates as the core locates closer to SMBH. But, SSA breaks somewhere uncertain at high frequencies and then it becomes fully transparent at over 1 THz region. Our goal in this proposal is to trace the relation between RM and observing frequency at the region of indefinite optical depths using Earth rotation polarimetry. Our science goal is possible for ALMA with relatively short observing time, i.e., total 4 hours (1 hour for each band) via Earth rotation polarimetry, comparable to the (1-band) full polarization mode, thanks to ALMA's super-sensitivity and wide coverage of observing frequencies. An elaborately tracing of RM would be carried out, in conjunction with simultaneous observations with KVN, over the total frequency coverage from 22 to 345 GHz. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-12-26T06:01:24.000 |
| 1002 | 2016.1.00701.S | 40 | ALMA maps of Jupiter during the Juno era | We request time to observe Jupiter with ALMA, as part of a dedicated world-wide campaign to support the Juno mission by: i) providing global context for the Juno microwave radiometer data, and ii) obtaining data over a broad range of frequencies to characterize, via a joint analysis, the planet's atmosphere (composition, temperature, dynamics) from the stratosphere down to hunderds of bars. | Solar system - Planetary atmospheres | Solar system | 2018-06-05T19:51:52.000 |
| 1003 | 2024.1.00132.S | 0 | ALMA exploration of star-forming galaxies near enriched cosmic gas structures at cosmic noon | Surveys of UV-bright galaxies near cool and enriched gas traced by MgII absorption reveal a puzzling lack of star-forming systems at cosmic noon compared to z< 1.5. To understand this unexpected result that challenges our view of how the circumgalactic medium (CGM) connects to galaxies, we propose ALMA CO-line search near 10 strong MgII systems, with the primary goal of understanding whether gas-rich, and highly star-forming galaxies undetected in the UV reside near the enriched absorbing gas. By carefully optimizing ALMA observations, this proposal will additionally target 18 CIV and MgII absorbers at z~3-4. With UV (MUSE) to sub-mm (ALMA) data for 28 metal-rich absorbers, we will: 1) Understand how galaxies of different SFR and gas content relate to the multiphase CGM; 2) complete the census of metals produced by active galaxies that are responsible for the cosmic enrichment seen in IGM/CGM; 3) establish the first correlations between gas fraction in cosmic noon galaxies and their CGM. ALMA data will be the critical missing piece to a complete multiwavelength view of the baryon cycle around cosmic noon star-forming galaxies. | Sub-mm Galaxies (SMG), Damped Lyman Alpha (DLA) systems | Galaxy evolution | 2025-10-18T12:28:44.000 |
| 1004 | 2024.1.00638.S | 0 | Toward the Representative [CII] 158um Lines in the Reionization Era | ALMAs view of the Epoch of Reionization has been largely limited to the most extreme, massive, brightest galaxies for which line-scans are feasible. The much larger, normal galaxy population is now finally within reach thanks to the synergy between ALMA and JWST. During JWST Cycle-1/2, the complete spectroscopic sample of star-forming galaxies was obtained using grism spectroscopy in the GOODS-South field. Here, we propose to obtain the view of the ISM in typical star-forming galaxies with an [OIII]-detected sample of 11 galaxies at 7.06. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2025-10-24T20:09:02.000 |
| 1005 | 2015.1.00455.S | 8 | A Breakthrough in Measuring SMBH Masses in Type II AGNs: ALMA's Potential? | We propose a high risky high impact project to test the ability to measure masses of SMBHs in type II AGNs with ALMA, which may open a new window for such studies. The directly measured line width of the radio recombination lines, with the combination of the broad line region size derived with AGN luminosity, can offer a critical constraint of the black hole masses in type II AGNs. We select Circinus, the nearest type II AGN with known broad line width (~3300 km/s), and apply to observe H35a (147 GHz) and H36a (135 GHz) simultaneously with the band 4 receivers. If we can detect such lines and determine the line width in Circinus with two hours on-source time at cycle 2, it is possible to systematically survey the masses of SMBHs in type II AGNs when ALMA is fully commissioned. If it is not successfully, we have to wait for JWST to do mid-IR spectroscopy observation, which will still suffer from the continuum contamination from the torus. We obtained a ranking with 20%-40%, which was assigned as a filler project during Cycle 2. If it can be scheduled in Cycle 2, we will not request re-observation for this project. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-11-18T06:46:04.000 |
| 1006 | 2017.1.01278.S | 27 | Observing Cosmic Ray Acceleration using ALMA in a Strongly Interacting Supernova 2014C | Cosmic Ray acceleration is an unsolved problem in astrophysics and the physical parameters associated with the process are largely unknown. A supernova (SN) shockwave that is interacting with the dense surroundings will naturally accelerate protons to very high energies, which may undergo collisions and produce secondary electrons through cascade of particles. Theoretically we have shown that this effect should be observable, most prominently in the ALMA bands. Observationally we have also uncovered SN 2014C which is strongly interacting with a dense shell in the surroundings. We show that SN 2014C is the most suitable candidate to determine the cosmic ray acceleration efficiency in young SNe for the first time. For this purpose we propose ALMA band-6 observations of SN 2014C. Now that the SN emission has faded below the sensitivity of all other telescopes operating in the mm-wavebands, ALMA is the only telescope capable of carrying out these observations. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2019-09-19T18:56:39.000 |
| 1007 | 2016.1.01152.S | 37 | Study of the first O-type 'swollen star' candidate | 'Swollen stars' are high-mass young stellar ojbects whose stellar surface is expanding due to active accretion on to them. While this phase of massive star formation is firmly predicted by models, no clear examples of O-type stars have been identified yet in such a phase. IRAS19520+2759 is, to our knowledge, the best 'swollen star' candidate with a luminosity > 10^5 Lsun, given its particular optical spectrum, lack of centimeter emission, its associated collimated outflow and an elongated, dense structure seen in C18O emission that is oriented perpendicular to the outflow. However, the association of the mm source and the optical source remains to be confirmed, and here we propose 0.15 arcsec angular resolution observations of the continuum at 3 mm (comparable to HST's 0.1 arcsec resolution in the optical) in order to determine the position and morphology of the mm source. In addition, we propose simultaneous observations of dense gas tracers well detected at 3mm with single-dish, in order to search for velocity gradients indicative of rotation/infall motions. | High-mass star formation | ISM and star formation | 2019-01-06T11:50:15.000 |
| 1008 | 2013.1.00087.S | 1 | Multi-Phase Imaging of the Outflow from the Edge-On Starburst Galaxy NGC 3628 | We propose to observe an outflow from the starburst galaxy NGC 3628 with various molecular gas phase tracers. Some of the most important insights on the outflow phenomenon have come from the presence of molecular gas. Stars form from molecular gas, so the molecular outflows from starburst regions directly affect the star formation activities and galaxy evolution, since the outflowing features directly indicate the decrease of fuel for forming stars and the quenching of star formation. These weak features have, however, rarely been observed (and only with CO) with previous less sensitive telescopes. As a case study, we observe the outflow from NGC 3628 with the diffuse (CO), dense (CS), and shocked (HCN, HCO+, and SiO) molecular gas tracers to obtain the detailed characteristics of the outflow for the first time. Combining this data set with the previously published X-ray (plasma) and Halpha (ionized gas) images, we compare the results with our ionization/hydrodynamics code, which simulate the outflow including molecular gas and dust for the first time, and reveal the evolution of the molecular outflow and galaxy itself, and study the effects of the outflow on the disk material. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2016-06-23T19:41:03.000 |
| 1009 | 2019.1.01364.S | 36 | How to form massive star and cluster in subsonic-to-transonic molecular clouds? | Our previous ALMA observations of the IRDC G350 massive clump show that it is dominated by subsonic-to-transonic motions. Using molecular line emission, we reveal 14 velocity-coherent filamentary structures. We also detected 49 continuum cores with typical masses of between 0.2 and 6 Msolar; only two cores have masses ~14 Msolar. The majority of cores (46) are found to be associated with filaments. However, we still do no know the processes of star formation within these complex filamentary networks. This followup ALMA program will: (1) constrain the evolutionary stage of identified cores using outflow and chemical tracers. (2) study how the gas is transported along filament down to dense cores with infall tracer. (3) achieve a complete census of dense continuum cores not detectable in previous ALMA observations to determine if subsonic filaments are actually fragmenting to form very low-mass cores. All of these discoveries will inform the initial conditions of massive star formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2022-09-22T13:34:40.000 |
| 1010 | 2021.1.00182.S | 205 | High-Speed Outflows and Dusty Disks during the AGB to PN Transition | As mass-losing asymptotic giant branch (AGB) stars evolve to planetary nebulae (PNe), the mass outflow geometries transform from nearly spherical to extreme aspherical. The physical mechanisms governing this transformation are widely believed to be linked to binarity and the associated production of disks and fast jets during transitional (post-AGB) evolutionary stages. We propose a comparative study of a representative sample of bipolar & multipolar post-AGB objects chosen on the basis of evidence for fast outflows and circumstellar disks. We will map CO J=3-2 and 6-5 emission with ~0.1" resolution in order to probe the spatio-kinematic structure of the collimated outflows and the central disk/tori. 3D radiative transfer modeling will be used to derive outflow momenta and masses. These results will help to distinguish between different classes of PN-shaping binary interaction models. By thus improving our understanding of the formation of aspherical PNe, our proposed study of post-AGB outflows and disks will generate new insight into a wide range of stellar mass ejection and binary interaction phenomena, ranging from novae to gravitational-wave-producing mergers. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2023-01-21T02:35:39.000 |
| 1011 | 2019.1.00377.S | 63 | Fresh sublimates in outburst object V883 Ori | FU Orionis objects (FUors) are young stellar objects in a burst-accretion phase. They are therefore excellent targets for the study of fresh sublimates, which are a unique and direct probe of the ice composition in the pre-eruption (i.e. quiescent) phase. During the quiescent phase, in the disk midplane, most molecules are frozen as ices onto grain surfaces where they react and become more complex as the disk evolves. Therefore, the complex organic molecules (COMs) detected as fresh sublimates provide us a unique inventory to study ice evolution in the disk. During Cycle 5, we detected several COMs in the disk of a FUor, V883 Ori, taking advantage of an outburst event. To fully investigate the ice composition in a protoplanetary disk, we propose to observe V883 Ori as a mini line-survey in band 6 where the continuum and line emission is less optically thick. By comparing the previously observed COMs composition of a hot corino, IRAS 16293 B, representing a very young pristine stage, with material sublimated from the disk of V883 Ori, which is more evolved, we will be able to constrain the ice evolution in this disk. | Low-mass star formation, Astrochemistry | ISM and star formation | 2022-11-25T07:30:57.000 |
| 1012 | 2017.1.00044.S | 2 | Toward Resolving the Magnetic Flux Problem in Star Formation: Mapping Poloidal B-field in Edge-on Disks | Poloidal magnetic field is expected in protostellar disks, if magnetic flux is dragged into the disks from star-forming dense cores. Such a poloidal field can play a key role in disk evolution and jet launching. However, direct evidence for its existence has been lacking. Here, we propose to follow up on our previous project to resolve the B-field morphology and search for poloidal field in the young, edge-on, and resolvable disks in two nearby disk-jet systems, HH 212 and HH 111, using polarization observation of thermal dust emission. If detected, it would mean that some of the core magnetic flux is indeed dragged into the disks and the poloidal field can indeed play a key role in both disk evolution and jet launching. A negative result would cast serious doubt on the poloidal-field driven disk evolution and jet launching. It would also imply that the long-standing ``magnetic flux problem'' is somehow resolved at large distances beyond the disks. To have the best chance of polarization detection, we request 2 Science Goals in Band 7 at 345 GHz at 0.035"-0.04" angular resolution. If succeeded, we would produce the first maps of poloidal B-field in young disks. | Low-mass star formation | ISM and star formation | 2019-05-18T09:35:16.000 |
| 1013 | 2015.1.01053.S | 28 | Confirming the First Class 0 Circumbinary Disk | Our VLA continuum survey of Perseus protostars has revealed extended circumbinary dust emission around the binary Class 0 system, IRAS 03292+3039. This extended emission is unique within the survey of 80 protostellar sources. Two plausible scenarios for these observations are either (1) an extremely dense inner envelope or (2) a gravitationally unstable, fragmenting circumbinary disk (a structure thought to be important in binary formation). To reveal the nature of the circumbinary emission around IRAS 03292+3039, we propose ALMA observations of this source in both 1.3 mm and 3 mm continuum and SO, C18O, 13CO, CO (J=2-1), three species of H2CO to act as temperature tracers, and the high density tracers H13CO+ and H13CN (J=1-0). The multiple wavelengths and tracers work together to provide a complete view of the kinematics and continuum emission on multiple size scales. Since gravitationally unstable, fragmenting disks have only been theorized to date, IRAS 03292+3093 provides an unique and ideal opportunity to examine the interplay between disk instabilities and binary formation and the chance to confirm the first discovered Class 0 circumbinary disk. | Debris disks | Disks and planet formation | 2018-03-11T00:34:19.000 |
| 1014 | 2016.1.00112.S | 44 | Probing the magnetic fields in the jet base of the gamma ray bright blazar PKS 1510-08 | Understanding of launching and evolution of relativistic jets of AGNs is one of the longstanding problems in astrophysics. Even though many theoretical studies and numerical simulations have shown that strong magnetic fields in the vicinity of spinning supermassive black holes play a critical role, not much direct observational evidence for the fields has been found. We suggest to observe PKS 1510-08, the quasar which is among the brightest blazars at gamma-rays observed by Fermi, at band 4, 6, and 7 to probe the magnetic fields in the jet base of AGN via investigating its Faraday rotation measure. We checked the feasibility of Earth-rotation polarimetry with ALMA with (i) Monte-Carlo simulations and (ii) applying it to ALMA archival data at band 6 and 7. This method is a unique technique for polarimetry with ALMA that allows us to derive a source's linear polarization with relatively short observing time (e.g., 1 hour) thanks to ALMA's extremely good sensitivity. Our observations will shed light on the unknown magnetic fields in the jet base of AGNs and be a pathfinder of systematic studies of AGN polarization at mm/sub-mm wavelengths via Earth-rotation polarimetry with ALMA. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-03-30T00:13:00.000 |
| 1015 | 2019.1.01275.S | 558 | Identifying the most obscured phase of accreting black holes at high redshift | We propose to obtain ALMA band 7 continuum observations with 0.5" angular resolution for the newly discovered 62 X-ray sources without any optical/NIR counterparts in the COSMOS field in order to understand the nature of these sources. This is possibly the first population of accreting black holes, or heavily obscured AGNs at high redshift. The proposed study will allow us to explore the most energetic and obscured phase of accreting black holes to understand the supermassive black hole (SMBH) growth in the context of the evolution of galaxies. This will be an important preparation for the future JWST, eROSITA, and WFIRST science -- our program will facilitate the detailed study of yet unknown heavily obscured population at high redshift, for the first time with sufficient statistics at earlier cosmic epochs. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-02-10T21:58:07.000 |
| 1016 | 2023.1.00361.S | 0 | ASPECS-One: Total Gas Masses in the Hubble Ultra Deep Field | The ALMA ASPECS and VLA COLDz molecular line scan Large Programs have led to the first systematic measurements of the CO luminosity function at high redshift, and the resulting evolution of the cosmic density of cold molecular gas out to z~7. These data unambiguously show that the rise and fall of the cosmic star formation history towards earlier epochs is fundamentally driven by an underlying change in the cold molecular gas content at the same epochs. We here propose to detect CO 1-0 emission in all z~1-2 galaxies in the HUDF securely detected in higher-J CO lines by ASPECS where this is possible with the new ALMA band 1 receivers, and to carry out an independent CO 1-0 line scan (i.e., luminosity function measurement free of systematic excitation bias) over the full ASPECS area "for free". By stacking sources based on ultra-deep HUDF VLT/MUSE integral-field spectroscopy, we will probe far below the nominal sensitivity limit. This will allow us to determine, for the first time, the typical gas excitation of CO-selected galaxies found by ALMA, and the range of gas fractions of HUDF galaxies at z~1-7 independent of pre-selection, serving as a critical pathfinder for the ngVLA. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1017 | 2012.1.00037.S | 17 | Disk masses in rho-Oph young Brown Dwarfs | Circumstellar disks are a signature of star formation by core-collapse and accretion, and, at the same time, the location for planetary system formation. The disks found around young brown dwarfs (BDs) provide an intriguing option to study star and planet formation under extreme conditions. BDs could form as stellar embryos ejected from multiple stellar systems; this scenario predicts low-mass and short lived disks that most likely will not form planets. Testing this and other ideas requires to determine the total mass and size of disks around BDs. So far, however, the presence of BD disks has mostly been inferred from infrared radiation emitted by optically thick dust in the inner disk regions, which does not constrain the global properties of the disk. Because of sensitivity limitations only very few BDs disks have been detected at submm wavelengths, where the disk mass can be reliably estimated. ALMA is uniquely suited to tackle this problem. Therefore, we propose to perform a deep search of submm emission from disks around BDs in Rho-Ophiuchius. The sample and sensitivity of this program have been selected to provide a strong constraint on models. The results will allow us to confirm whether young BDs in Rho-Oph have similar disk properties as low mass stars in the same region, providing a strong statistical benchmark for the competing formation theories, and whether BDs disks are capable of sustaining planet formation. | Disks around low-mass stars | Disks and planet formation | 2015-09-18T15:20:02.000 |
| 1018 | 2023.1.00610.S | 0 | Witnessing the molecular enrichment of the circumgalactic medium | We propose an ALMA study of a remarkable 100-kpc structure around a compact starburst/AGN at z=0.5. The structure is a huge nebula traced by ionised oxygen, and resembles a limb-brightened bipolar bubble, driven by feedback from a central starburst or AGN. It is the largest and most luminous [OII] nebula yet observed. In this object we are gaining a rare insight into the deposition of metals/energy far into the circumgalactic medium (CGM). Current ALMA observations reveal CO(2-1) emission linking the central galaxy to the wider nebula, implying that molecular gas is either being driven out of the galaxy or is cooling out of a hotter outflow. Key questions are (1) how far does the molecular component extend into the CGM? (2) how much mass does it contain? and (3) what are its properties? We will address these questions with new CI(1-0) and 13CO(2-1) observations, revealing the diffuse molecular gas and allowing us to assess the dynamical state of the cold gas phase. Linking the cold molecular gas phase to the more extended, warmer ionized outflow is crucial for a better understanding of the role the CGM plays in the baryon cycle of galaxies. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2025-11-14T16:08:21.000 |
| 1019 | 2016.1.00604.S | 6 | Understanding Magnetic Field Morphologies of Star Formation Depending on Observational Size-scales | In order to investigate magnetic field morphology in 1000 AU to 100 AU scales, we propose for ALMA polarimetric observations toward two Class 0 protostellar systems which have strong polarization detection in our CARMA observations. Recently, a discrepancy in magnetic field morphology has been reported over different target samples and scales: magnetic fields aligned or misaligned along bipolar outflows. Our ALMA observations will shed a light on where the discrepancy comes from: whether it is due to different scale-sensitive observations and what the detailed magnetic field looks like indeed. These results will provide insights about the relationship between magnetic fields and disk formation at the early evolutionary stage, as well as about the magnetic field roles in star formation. | Low-mass star formation | ISM and star formation | 2018-03-01T16:33:28.000 |
| 1020 | 2012.1.01000.S | 14 | Mapping the Dense and Shocked Gas at 100 pc Scales in the Nuclear Regions of the Antennae galaxies | Dynamical interactions and mergers of two gas-rich galaxies can result in galaxies bright in IR luminosity. Numerical simulations have predicted the ubiquitous presence of large scale central gas inflow that leads to central gas accumulation and subsequent starburst activity. As a first step toward better understanding the process that leads to IR-bright starburst activities in nearby systems, we have been leading an extensive program to study the nearest gas-rich intermediate stage merger, the Antennae galaxies (NGC 4038/9). Using the SMA and ALMA Science Verification data, we found kinematical evidence that suggest radial inflow of gas into the nucleus in NGC 4039 and high CO(3-2)/(1-0) ratios in both nuclear regions suggesting higher excitation there. While the CO emission is extremely useful to study the overall molecular gas mass and the gross kinematics, it does not provide a quantitative measure of the dense/shocked gas that are directly related to star formation activity. Here we thus propose a total of 1.4 hours to image both nuclear regions of the Antennae galaxies in the 5 dense/shocked gas at 100 pc scales in Band 3. We will probe the most active dusty star forming regions using 3 dense gas tracers (HCN, HCO+, CN), and examine their relation to the stellar potential and star formation activities traced in multi-wavelength images. We will also investigate whether the distribution of the shocked gas (SiO, CH3OH) shows correlation with the region where the CO velocity field shows significant deviations form circular motion and determine the origin of large-scale molecular shocks using the SiO/CH3OH ratio. | Merging and interacting galaxies | Galaxy evolution | 2015-10-17T19:40:50.000 |
| 1021 | 2016.1.01198.V | 0 | Zooming into the heart of the closest radio galaxy: 1mm VLBI Observations of Centaurus A | Joint VLBI observations with phased-up ALMA and the Event Horizon Telescope (EHT) at 1.3 mm provide for the first time the required sensitivity and angular resolution to image the jet formation region of the closest radio-loud galaxy, Centaurus A (Cen A). Due to its relative proximity (3.8 Mpc), this source is a unique laboratory for investigating jet formation, collimation, and the origin and mechanism(s) of high-energy emission on the smallest scales. At a declination of -43deg, Cen A has not been well accessible for mm-VLBI until now. Additionally, the innermost part of the jet-counterjet system is optically thick at longer wavelengths, i.e., only mm-VLBI allows us to zoom into the jet launching region. | Outflows, jets, feedback | Active galaxies | 2018-10-20T14:57:17.000 |
| 1022 | 2018.1.01532.S | 1 | Magnetic field study of the disk and outflow of HH30 | HH30 is a young T-Tauri star that drives a bipolar jet. In cycle 2 we obtained ALMA data in band 6 at 0.2'' resolution to study the disk and the 12CO outflow previously reported by Pety et al. (2006). We managed to weel characterize the disk of HH30, that is in Keplerian rotation, and the monopolar outflow of HH30. The CO outflow has a hollow conical morphology and is rotating in the same direction as the disk at a velocity of ~0.6 km/s. The characteristics of the outflow in terms of mass ejection rate (> 9.10^{-8} Msun/yr) and conservation of angular momentum best favor MHD disk winds models where a large-scale poloidal magnetic field is anchored in the disk (see Feirrera et al. 2006). To test forwards these models, we request full polarisation 12CO, 13CO and continuum observation of the HH30 system. We will test the morphological predictions for the magnetic field of these models (helicoidal morphology in the outflow - poloidal in the inner disk - and most likely toroidal in the outer part of the disk) with observation. We will also address the mono-polarity of the disk with respect to the magnetic field morphology. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2020-03-08T17:19:08.000 |
| 1023 | 2011.0.00017.SV | 0 | Science verification observation of 3C 286 | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-06-24T14:02:08.000 |
| 1024 | 2013.1.00735.S | 8 | Revealing Interstellar Matter Structure at the Heart of NGC 253 | We propose a high spatial resolution observation of a hydrogen recombination emission line (H26alpha) toward the center of nearby starburst galaxy NGC 253 in the ALMA Cycle 2. Based on an ALMA Cycle 0 data, a hydrogen recombination emission from NGC 253 at (sub-)millimeter wave was turned out to be sufficiently bright and powerful tool to investigate properties of ionized interstellar medium. We found peculiar motion of ionized gas around the center of NGC 253. The gas have larger velocity width than molecular gas, and show totally different kinematics. High spatial resolution (<0.''2) and sensitive observation of H26alpha line simultaneously with molecular emission lines will be able to catch ionized shells of compact molecular cloud in the heart of starburst region. The H26alpha data also provide clue to the H40alpha peculiar velocity structure because the shells might be the origin of large velocity width. | Starbursts, star formation | Active galaxies | 2016-06-15T10:46:01.000 |
| 1025 | 2015.1.00425.S | 4 | Direct constraint on grain size at a planet-forming region with polarization observation | We propose to detect the polarized emission of a protoplanetary disk at mm wavelengths due to dust scattering. Although polarized emissions at mm wavelengths have been expected to be emitted from elongated dust grains aligned with magnetic field, the self-scattering by large dust grains can account for the polarized emission at mm wavelengths even without the grain alignments with magnetic field. The detection of polarized emission of dust scattering would be direct evidence of grain growth because large grains have a large albedo. The target object is one of the brightest source in protoplanetary disks. Based on the modeling of the ALMA Cycle 0 data and our theoretical calculations, the polarization due to dust scattering is detectable (>0.3%) if the maximum grain size is in the range from 40 micron to 300 micron. Either detection or non-detection puts a constraint on the grain size. This is the first trial to use mm-wave polarization as a direct evidence of the grain growth in a protoplanetary disk. | Disks around low-mass stars | Disks and planet formation | 2017-12-22T00:00:00.000 |
| 1026 | 2022.1.00802.S | 15 | Complex Organic Molecules in Compact Obscured Nuclei | Luminous and ultraluminous infrared galaxies are powered by either bursts of star formation or by accreting supermassive black holes, and are important to our understanding of galaxy growth throughout the Universe. Some of these galaxies contain very deeply embedded and compact nuclei (CONs) that appear to rapidly evolve, are hot (T > 100 K), and opaque (N(H2) > 10^24 cm^2) and have been detected via the emission of strong vibrationally excited HCN lines. The chemistry in CONs seems to be very rich, with high abundances of many molecular species, among which CH2NH, methanamine (a likely precursor of glycine). We propose that CONs indicate a unique phase of chemical evolution, with enhanced complex organic molecule (COM) production similar to, orgreater than, Galactic hot cores, related to nuclear growth in galaxies, and not yet revealed by Galactic studies or studies of known AGN. We would expect COMs to be widespread and abundant in CONs. In this proposal we ask for ALMA Band 6 time to survey multiple transitions of a sample of COMs in IC 860, one of the most chemically rich CONs so far observed. | Galaxy chemistry, Galactic centres/nuclei | Galaxy evolution | 2024-07-13T15:28:19.000 |
| 1027 | 2012.1.00554.S | 6 | Most active on-going star formation in the Local Group: Resolving filaments and cloud cores in the LMC | High-mass star forming regions are relatively few in the solar neighborhood. Much more active and extensive high-mass star formation is found outside the Milky Way. Studies of such regions are important since they provide a link to distant active starbursst. Our target here is the giant molecular cloud (GMC) in N159, an HII region located in the nearest external galaxy Large Magellanic Cloud having lower metalicity than the Milky Way. N159 is the most intense and concentrated molecular cloud as shown by the brightest 12CO J=3-2 source in the LMC, and thus ideal to study the current most-massive cluster formation in the Local Group. Nearby HII region, 30Dor, is not forming massive clusters anymore and is not a suitable witness to cluster formation. Theories predict that cluster-forming regions consist of pre-stellar cores of sub-pc/pc scale and filaments connecting these cores. Such a picture finds increasing support from recent Herschel observation etc. In ALMA cycle1 operation we propose to observe the most active on-going star formation sites in J=2-1 and 1-0 transitions of 12CO and 13CO, J=2-1 transition of CS and dust continuum in band 3 and 6. These observations should provide a powerful tool to probe molecular cores and their connecting filaments for a large density range, 10^2cm^-3 to 10^4cm^-3, relevant to quantify their physical parameters at sub-pc scales. We request 4.92hrs ALMA cycle1 observing time in total in order to achieve this goal. | Magellanic Clouds | Local Universe | 2015-08-21T12:08:06.000 |
| 1028 | 2019.1.00459.S | 70 | Evolution of ISM Masses in the First 2 Gyr at z = 3 - 6 | We propose to extend our very successful ALMA survey of the ISM contents of galaxies out to the epoch of reionization and initial galaxy formation at z = 3 to 6. In this epoch, the ISM masses generally dominate over stellar masses, thus determining early galaxy formation and evolution. Our observations will probe the ISM masses using the long wavelength Rayleigh-Jeans (RJ) dust continuum emission with ALMA continuum observations tailored to maintain lambda_rest > 300 microns and detections at 5-10 sigma based on the expected fluxes of each galaxy. Two samples at z = 3 - 6 that cover a range of galaxy stellar masses and SFRs will be observed: 21 main sequence galaxies from the ALMA Cycle 5 large project ALPINE, and a sample of 7 starburst galaxies having existing Herschel far infrared detections. All galaxies have spectroscopic redshifts and infrared SFRs (from ALPINE 150 mic continuum detection or from Herschel). Dynamical mass estimates are available from the ALPINE [CII] line imaging, providing a powerful calibration of the mass estimates; ALPINE provides the largest galaxy sample with [CII] detected galaxies at z > 4 to date. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2021-08-07T18:19:59.000 |
| 1029 | 2024.1.01278.S | 0 | High-resolution Follow-up of the Compact Clumps in CO 0.02-0.02 | CO 0.02-0.02 is a peculiar molecular cloud in the Galactic center. Its spatial compactness (d<5pc) and extremely broad velocity width (dV>100 km/s) place it in the category of high-velocity compact clouds. Since its arc-shaped cavity of molecular gas appears to enclose a group of point-like infrared sources, it has been suggested that CO 0.02-0.02 was accelerated by a series of supernova explosions in an embedded stellar cluster. Recent ALMA Cycle 7 observations in the CO J=3-2 line have revealed that its compact high-velocity end contains several unresolved ultra-compact clumps (UCCs) that could not be resolved by the 1" resolution. Here, we propose to perform mapping observations towards the high-velocity end of CO 0.02-0.02 in the CO J=4-3 line with 0.1" resolution. If the proposed gravitationally accelerated model of an embedded stellar cluster is clarified by the spatially resolved UCC map, it will lead to the understanding of the acceleration mechanism of HVCCs, as well as providing a new way to explore missing stellar clusters. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1030 | 2011.0.00772.S | 0 | Giant Molecular Cloud Survey Toward bar and arm of the nearby Galaxy M83 | Molecular-rich galaxies with prominent galactic structures are the most suitable targets for the investigation of the evolution of giant molecular clouds (GMCs, size ~50pc) which lead massive star formation. However, due to the limited mapping ability of the existing telescopes, observations toward such molecular-rich galactic disks were limited with coarse resolutions (over 200pc), up to recent. Our recent pilot studies made with GMC-scale resolutions have revealed an evolutionary sequence of GMCs and suggested one of the necessary conditions for GMCs to initiate massive star formation is the virialization of the natal GMCs on global scale, despite star formation is a sub-pc scale phenomena. However, previous studies were limited with small survey area. To robustly verify our findings and make a further constraints, we propose wide-field observations in the CO(1--0) toward the nearby barred galaxy M83 with a significantly larger area compared to the previous studies. The proximity, presence of prominent galactic structures, molecular-dominated gas disk, and accessibility from the ALMA site make this galaxy most suitable for our purpose. Combining ALMA data with our single-dish data taken with the NRO 45m telescope we will recover the total CO flux. The survey will enable to identify hundreds of GMCs from the combined ALMA+45m data. The identified GMCs will be compared with the existing multiwavelength datasets to identify associated HII regions and star clusters to robustly state their evolutionary stage. By comparing the properties of identified clouds which reside in variety of evolutionary stages and galactic environments, the conditions required for onset of massive star formation will be strictly verified and further constrained. | Giant Molecular Clouds (GMC) properties, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2013-09-28T08:06:00.000 |
| 1031 | 2023.1.01381.S | 0 | Probing early structure formation with Planck-selected protoclusters | What did galaxy clusters look like before they virialized around z=2? We don't really know, since typical galaxy cluster selection techniques rely on virialization to begin with. Finding examples of galaxy clusters at this stage of evolution (i.e. protoclusters) is therefore crucial for understanding how large-scale structure formation played out. Using maps of the submillimetre sky taken by Planck, over 2000 high-z objects were selected, and subsequent follow-up has established these as excellent z~2 protocluster candidates. The redshifts of two of the most likely protoclusters in this sample have now been determined, and in this proposal we aim to confirm up to 18 protocluster galaxies in these fields. Our sample will be large enough to estimate protocluster masses through velocity dispersions, while on the individual galaxy scale we will investigate whether protocluster galaxies have lower gas depletion timescales than field galaxies. If successful, our selection method will open up a new avenue for studying statistically significant numbers of protoclusters selected from large-sky submillimetre surveys, as opposed to focusing on individual systems. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2024-12-27T13:21:32.000 |
| 1032 | 2013.1.00355.S | 0 | The Morphology of the Magnetic Field of HL Tau | The formation of disks around protostars is thought to be regulated through magnetic fields, and theoretical models suggest that the fractional polarization should be approximately 2-3%. Nevertheless, resolved observations of disks in T Tauri stars (TTS) have remained undetected and are constrained to have fractional polarization of less than 1%. However, with CARMA observations of HL Tau, we recently found the first detection of a resolved magnetic field about a TTS. Unfortunately, such observations have insufficient resolution to discern the true magnetic field morphology. Therefore, HL Tau is the quintessential source for follow-up ALMA observations. High resolution ALMA observations will allow us to discern the morphology of TTS magnetic fields, which will supply theory with the first observational constraint of the magnetic field morphology during the Class II stage of star formation. | Disks around low-mass stars | Disks and planet formation | 2016-10-29T08:12:54.000 |
| 1033 | 2016.1.01079.S | 53 | BASIC: A Bright ALMA Survey of SMGs in the Chandra Deep Field-South | We propose an ALMA survey of a large, uniformly selected sample of 76 bright SMGs (BSMGs, ~1 source per 1.5 arcmin^2) discovered with SCUBA-2 down to the confusion limit of S(850um)>2 mJy in the GOODS-S/CDF-S. The data probe a large BSMG sample that for the first time bridges the critical transition range in SFR (~500 M_sun/yr) between the rare hyperluminous, dusty, optically faint galaxies found in shallow, wide-area submm surveys (e.g., LABOCA, HATLAS, SPT, Planck) and the extinction-corrected UV-selected Lyman Break Galaxies that are being probed with direct ALMA observations of small areas. These two populations are essentially disjoint, and key physical changes in star formation mechanisms may be occurring over this SFR range. These ALMA observations for the BSMGs will allow us to: determine blended source fractions; measure their physical sizes, morphologies and offsets; pinpoint optical, NIR, and X-ray counterparts; construct SEDs, and estimate SFRs and dust mass for these unique sources. *This is a resubmission of a successful rank-B Cycle 3 proposal. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-10-09T07:31:37.000 |
| 1034 | 2017.1.01375.S | 18 | The 12C/13C Anomaly of CCH in the Vicinity of the Protostar in L1527 | Anomaly in molecular isotope ratios can be an important tracer bridging the missing link between molecular cloud chemistry and the planetary chemistry. For instance, deuterium fractionation in molecules has extensively been studied for this purpose. In the last decade, we have been reporting a significant anomaly in the 12C/13C ratio in various carbon-chain molecules; dilution of 12C/13C ratios in molecules and different 13C abundances among different carbon atoms in a single molecular species. Apparently, such 12C/13C anomaly can be used to trace evolution of organic materials. In this proposal, we will observe the 12C/13C ratio of the carbon-chain molecule CCH in the low-mass star-forming region L1527 to study whether the 12C/13C anomalies of this molecule in the 2000 au scale found in our single-dish observations can also be found in the 100 au scale around the protostar. This observation will provide us crucial information on the fate of the 12C/13C anomaly of carbon-chain molecules found in molecular clouds, and on its relation to the 12C/13C anomaly in pre-solar organic materials found in meteorites. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-05-11T22:41:28.000 |
| 1035 | 2011.0.00735.S | 0 | Molecular Gasdynamics in the Central Elliptical Galaxy of the NGC 5044 Cool-Core Group | The central elliptical galaxies of cool-core groups and clusters rank among the most molecular-gas-rich galaxies in the Local Universe. Such groups/clusters exhibit a strong central peak in their X-ray emission, indicating intensive cooling of the X-ray gas in the group/cluster core. In the absence of sufficient reheating by radio jets from their central galaxies, the gas in the group/cluster core should cool below X-ray temperatures and flow inwards (an X-ray cooing flow), thus depositing atomic and molecular gas in the central galaxy. In the only such galaxy so far mapped in CO, the central galaxy of the Perseus cluster, the molecular gas is distributed in radially-infalling filaments indicative of an X-ray cooling flow. Such molecular structures have not previously been observed in any other galaxy, and call to attention an important galactic-scale phenomenon yet to be fully elucidated. Here, we propose to image the molecular gas in the central elliptical galaxy of a cool-core group, NGC 5044. Unlike the Perseus cluster where the X-ray gas is reheated by a powerful AGN outburst from its central galaxy, in the NGC 5044 group gas reheating occurs through the cumulative effects of many weak AGN outbursts from its central galaxy as is more characteristic of cool-core groups/clusters. Our goals are to determine where the molecular gas in NGC 5044 is being deposited or dragged outwards, and through comparisons with the central galaxy of the Perseus cluster gain insights not possible from studies of one system or environment alone. | Galaxy groups and clusters, Outflows, jets, feedback | Cosmology | 2014-03-04T02:22:00.000 |
| 1036 | 2021.1.01259.S | 46 | Studying post-AGB stars using carbon and oxygen isotopic ratios | Surface isotopic ratios are powerful tools to study the properties of low- and intermediate-mass stars. Mixing processes that take place at well-defined moments in the evolution of these stars polute their external layers with products from nucleosynthesis happening in the core. Whether these mixing processes take place and the extent of the mixing depend mainly on the initial stellar mass and metallicity. Hence, isotopic ratios can be used to probe these two parameters and the evolutionary stages of stars. Observations of an increasing number of low- and intermediate-mass stars in the post-AGB phase show isotopic ratios that are not compatible with theory, given that these systems should have experienced all expected mixing processes. This suggests that these systems have followed non-standard evolutionary paths. However, the number of post-AGB systems with measurements of the relevant isotopic ratios is still small and an overview is lacking. With this proposal, we will determine the isotopic ratios of oxygen and carbon towards a sample of 20 post-AGB stars. This is the first step towards building a much-needed broad overview of isotopic ratios in post-AGB sources. | Post-AGB stars | Stars and stellar evolution | 2023-12-22T13:26:11.000 |
| 1037 | 2016.1.01537.S | 48 | Measuring disk and outflows properties around the intermediate-mass jet-driving source HH900 | HH 900 is a peculiar protostellar jet+outflow system that emerges from a small, tadpole-shaped globule in the Carina Nebula. External irradiation from the many O-type stars in the region light up the jet, allowing for better estimates of the density, velocity, and mass-loss rate than is typically possible for the jets from higher-mass protostars. HH 900 has the highest mass-loss rate of the known protostellar jets in Carina and we therefore infer a higher M_ZAMS driving source. From optical and IR images and spectra, we know that the irradiated jet must originate from an unseen protostar embedded in the optically-opaque globule. We propose to use the superior sensitivity and angular resolution of ALMA to detect the protostar, circumstellar disk, and jet+outflow inside the globule. From continuum observations, we identify the driving source and estimate the mass of the globule. We will measure the properties of the jet and outflow inside the globule with SiO and CO and compare the derived properties with constraints from the atomic jet and outflow. Finally, we will examine the CO isotopologies for evidence of Keplerian rotation in the edge-on circumstellar disk. | Outflows, jets and ionized winds, Intermediate-mass star formation | ISM and star formation | 2018-10-03T14:05:19.000 |
| 1038 | 2018.1.01152.S | 19 | Extreme feedback in a cool core cluster at z=0.2 | We propose to detect and measure with ALMA the cold molecular gas reservoir that feeds the central supermassive black hole (SMBH) within the Brightest Cluster Galaxy (BCG) sitting at the centre of the cool core cluster Abell 2667 at z=0.234. We will observe the CO[3-2] transition in band 7, with an angular resolution of 0.3" (corresponding to 1.1kpc at the redsfhit of the cluster), in order to spatially map its complex structure, that extends for roughly 30kpc. Eventually, we will combine the ALMA cold gas maps with the spatially resolved optical spectroscopy from MUSE (GTO program 094.A-0115(A), P.I. J. Richard) that reveals the presence of multiple gas components with different velocities with respect to the BCG rest-frame. We also aim at spectrally resolving the CO line, to detect multiple gas motions as for the ionized component, and eventual molecular outflows (suggested by the presence of blueshifted emission lines in MUSE data). The existence of shallower ALMA data in the archive allowed us to carefully predict the required sensitivity to reach our science goals, that will basically test the effect of feedback on the inner environment of (one) cool core cluster. | Galaxy groups and clusters | Cosmology | 2020-09-03T17:41:53.000 |
| 1039 | 2019.2.00128.S | 208 | A Comprehensive [CII] Survey of Herschel-Selected Starbursts at z=3-6 | Based on a survey of the most luminous massive starburst galaxies found in >1000deg2 observed with Herschel, we have obtained a comprehensive sample of nearly 100 sources with secure, CO/CI-based spectroscopic redshifts. Here we propose to detect [CII] 158um emission from the star-forming ISM at z=3-6 in all 33 galaxies in our sample that are observable with the ACA, i.e., twice as many as in the largest massive starburst samples currently available. In combination with the rich suite of diagnostics already available, this study will provide critical insight into the physical properties of the ISM that set the conditions for star formation for a statistically significant sample, including a study of feedback based on the line profiles. Based on 9 systems in our sample for which we have already obtained <=1kpc resolution [CII] imaging with the ALMA 12m array, the ACA data will also provide a critical test for the potential presence of low surface brightness emission on >5-10kpc scales due to an enriched cold circum-galactic medium missed by high-resolution studies, as has been suggested to be present in star-forming galaxies in the early universe by some recent theoretical work. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2022-08-30T17:33:03.000 |
| 1040 | 2012.1.00932.S | 0 | G0.253+0.016: A dense Galactic Center Cloud with low Star Formation Potential | We wish to study the temperature structure and the reservoir of dense gas in the Galactic Center molecular cloud G0.253+0.016. This is a cloud with unique physical properties: single-dish dust emission data indicates an enormous density (2x10^5 M_sun within 3 pc radius), but the cloud is essentially devoid of signposts for star formation (i.e., IR sources, Hii regions, masers). SMA and CARMA data (submitted to ApJ) reveal that very few cores of very dense gas exist in the cloud. The requested ALMA data form part of a long-term systematic study of the Central Molecular Zone. The main aim of the current proposal is to probe the cloud's temperature structure. Line ratios indicate gas temperatures ~80K, but dust emission suggests values <30K. This difference is surprising, since the coupling of dust and gas temperatures should be efficient at the high observed densities. The high gas temperature may suppress fragmentation and therefore star formation. Given cooling times of a few 10^4 yr, the dust-gas temperature difference may hint at heating in a cloud-cloud collision. A secondary goal is to detect dense cores in dust emission. Despite relatively high sensitivity, the SMA was so far unable to detect such cores. The requested ALMA data will be more sensitive by a factor 20, and will thus help to constrain the density structure very well. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2015-05-12T00:00:00.000 |
| 1041 | 2015.1.00395.S | 8 | Environmental impacts on gaseous processes in the two densest proto-clusters at z>2 | Our "Mahalo-Subaru" project has been systematically mapping out star formation activities with H-alpha, [OII], and [OIII] emitters over the peak epoch of galaxy formation and across various environments. It has revealed not only filamentary/clumpy structures of proto-clusters but also very high star forming activities therein especially at z>2. We now propose a fully coordinated program "Gracias-ALMA" which observes CO lines and dust continua of the Mahalo sample. We will scrutinize the physical states and the mode of star formation both grobally and locally within galaxies, and identify the physical processes that govern star forming activities as a function of time and environment. In this cycle-3 proposal, we aim to detect CO(3-2) lines from >22 bright H-alpha emitters belonging to the two densest proto-clusters in our Mahao sample, namely, USS1558 at z=2.53 and PKS1138 at z=2.16. We will explore the molecular gas processes (star formation, inflows/outflows, stripping) in the early stage of galaxy formation under the influence of surrounding environments, in comparison with our cycle-2 data for identically selected sample of H-alpha emitters in the general field at z=2-2.5. | Starburst galaxies, Galaxy Clusters | Active galaxies | 2017-06-14T13:33:38.000 |
| 1042 | 2022.1.00197.S | 0 | Are envelope-to-disk accretion streamers associated with magnetic fields in a young Class 0 protostar? | Some simulations show that mass accretes asymmetrically from cores to protostellar disks via narrow streams of material, especially when magnetic fields are taken into account. Recently, such accretion streamers have begun to be observationally detected, hinting that streamers could play a fundamental role in the mass accretion and disk formation processes. Further, how large disks (radii >10 au) form early in the embedded Class 0 phase remains unclear since magnetic braking can hinder disk formation. If the magnetic field orientation is misaligned with the disk rotation axis, or if field strengths are weak, disks with radii of ~100 au may theoretically form in the Class 0 phase. Observations of magnetic field properties of material flowing directly into disks are critical to test these expectations. Our target is the only Class 0 protostar with data showing that dust is cospatial with two kinematically confirmed streamers feeding a disk >100 au in radius. We propose for ALMA Band 6 polarization observations of the dust in the streamers to measure magnetic field orientation and strength to test the theoretically expected influence of magnetic fields on disk formation. | Low-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1043 | 2017.1.00178.S | 6 | Submillimeter H2O masers in high-mass YSOs | It is still unclear how angular momentum is extracted to allow mass accretion onto circumstellar disks and newly born YSOs even in low-mass star-formation. This "angular momentum problem" is also crucial for high-mass cases to understand mass accretion mechanisms. In ALMA cycle 0, we detected velocity gradients perpendicular to the outflow in the 321 GHz H2O maser toward a high-mass YSO Orion Source I. Our results show that the 321 GHz H2O maser could be a new probe for outflow rotation in high-mass YSOs. To verify this hypothesis, we propose the first survey of the 321 GHz H2O maser in 7 high-mass YSOs associated with the 22 GHz H2O masers. We aim to reveal dynamical structures of high-mass YSOs traced by the 321 GHz H2O maser. If we detect rotation motions with the 321 GHz H2O maser, we will discuss enclosed mass and specific angular momentum of the outflow quantitatively. Multi-transition data of the 321 GHz and 22 GHz masers will constrain density, temperature, and H2O abundance in the outflow. These data will provide outflow mass, linear/angular momentum, kinetic energy, and their loss rates, which are essential in theoretical models of high-mass star-formation processes. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2021-02-12T10:36:27.000 |
| 1044 | 2019.1.01677.S | 60 | Probing spatially resolved winds in powerful starbursts at high redshift with Hydrogen Fluoride | Galaxy evolution is driven by the balance between gas inflows through accretion streams and mergers, the efficiency of star formation, and AGN and starburst driven outflows. Outflows play a key role in the gas cycle of galaxies by regulating star formation and polluting the CGM and IGM with mass, energy, and metals. The physical characteristics of outflows -- their mass loading and energy and momentum outflow rates are difficult to determine. The most powerful diagnostic lines of outflows should be observed in absorption to remove the directional ambiguity and provide robust estimates of the terminal velocity, be the dominate species for its primary element, and probe a wide range of column densities. The HF molecule fits all of these criteria (uniquely) well. To estimate the parameters of spatially-resolved molecular outflows, we propose to observe a sample of highly lenses SPT sources at z=3.7-4.3 in HF J=1-0, 2 water lines, and CO(10-9) in band 6. These observations will provide deep insights into the spatially-resolved characteristics of outflows and perhaps constrain the energy dissipated in the dense molecular gas through shocks with the water lines and a high J CO line. | Starbursts, star formation | Active galaxies | 2021-03-29T10:17:42.000 |
| 1045 | 2016.1.01115.S | 37 | Fragmentation and chemical evolution in high mass star formation | Understanding the early evolution of high mass star formation is one of the major open topics in star formation research. To investigate this, we propose to map a massive star forming filament within the G10.3-0.1 complex in band 6 and 7 with both 12m array and ACA. The clumps on the filament are in different evolutionary stages--from a potential starless clump to ultracompact HII regions--gives us exceptional opportunity to study key parameters as a function of the evolutionary stage (i.e., time). The main scientific goals are: a)Resolve the clumps down to 0.009pc to investigate how exactly the fragmentation proceeds from less evolved to more evolved clumps, such as the fragment masses and separations, and compare the results with Jeans and turbulent fragmentation theories. b)Investigate the radial density profile of each resolved core, and establish whether it changes as a function of the evolutionary stages of the cores. c) Investigate the deuterium fraction (N(N2D+)/N(N2H+)) characteristics between the onset of gravititional collapse and more evolved stages. d)Study the kinematics of the high-mass star forming complex, investigate the global collapse from clump to core scale. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-05-06T00:00:00.000 |
| 1046 | 2023.1.00190.S | 0 | A Quest for Stellar Embryos: observation of the most nearby first-core candidate | One of the biggest issue in star formation is that we have never witnessed the first hydrostatic core (FHSC) that must be formed in dense cores short before the formation of protostars. It holds vitally important information of stellar initial condition. However, because it is a compact and low-mass object with cold outer molecular gas, FHSC is extremely faint and thus difficult to be detected. Also because the lifetime is very short, ~ a few 1000 yrs, very extensive survey is required for the discovery. As a good observable indication, FHSC is suggested to drive slow molecular outflow. The target of MC35-mm was discovered as a result of comprehensive ACA survey of prestellar cores in Taurus. It is the most promising candidate with compact mm emission with no IR counterpart driving slow molecular outflows. In addition, among other candidates known to date, MC35-mm is the most nearby object. The proposed higher-resolution 12m array observations can judge if the source is a genuine FHSC or more evolved protostar based on (1) point-like continuum emission of a few mJy confined within the 50 AU beam, (2) outflow velocity of < 5 km/s, and (3) the outflow lobes extent of < 1000 AU. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2025-11-13T04:18:33.000 |
| 1047 | 2023.1.01478.S | 0 | The First Kinematic Characterization of Magnetically-driven Winds in a Protoplanetary Disk using Atomic Carbon | Understanding the accretion processes of protoplanetary disks is essential to understanding the evolution and dispersal of the disk, which ultimately sets the overall planet forming capability. Recent simulations have challenged the traditional viscous disk accretion scenario. Now, simulations suggest that magnetohydrodynamic (MHD) disk winds may be the primary drivers of accretion. However, observational constraints on MHD winds are still critically missing. Recently, large-scale winds have been detected in 12CO and 13CO in the planet-forming disk around the T Tauri star AS 209. In addition, archival data show clear CI emission in the disk, although kinematics of the winds cannot be analyzed due to inadequate data quality. To this end, we propose to observe [CI] P1-P0 line emission in the AS 209 circumstellar disk with three goals in mind: (1) measure the CI line flux, (2) locate the CI emission surface, and (3) constrain the three-dimensional velocity structure of the CI emission. With these measurements, for the first time, we will be able to characterize MHD winds across multiple heights in a protoplanetary disk, which will help to directly test wind-driven accretion scenario. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 1048 | 2017.1.01514.V | 0 | Magnetic field in the vicinity of central black holes in 3C273 and 3C279 | Multifrequency VLBI polarimetry is the best tool to probe the strength and structure of the magnetic field in the inner jets and in the extreme vicinity of supermassive black holes. We propose here to use the GMVA+ALMA observations of 3C273 and 3C279 in combination with our planned RadioAstron observations at 22 GHz in order to obtain the most detailed picture of polarized emission distribution and Faraday rotation measure in these objects on scales down to 20-30 microarcseconds. The phased ALMA will be crucial for improving the r.m.s. noise and structural sensitivity of the 86 GHz images, which will enable probing the rotation measure in regions with much weaker polarization signal and much steeper spectral index. Combined with the information on jet spectrum, opacity, and collimation, the polarization and rotation measure imaging will enable reconstructing the three-dimensional distribution of the magnetic field and making a founded judgement on its origin and the exact role in formation and acceleration of relativistic flows in AGN. | Starbursts, star formation | Active galaxies | 2020-11-20T00:00:00.000 |
| 1049 | 2021.2.00004.S | 154 | Mapping Molecular Irradiation Tracers in Bipolar Planetary Nebulae | Planetary nebulae (PNe) offer our last and arguably best look at the products of intermediate-mass stellar nucleosynthesis, just before that material is incorporated into the ISM. A subset of PNe with pinched-waist, bipolar structures retain significant masses of cold, dense molecular gas and dust that is irradiated from within by UV and soft X-rays from exceedingly hot, rapidly evolving central stars. Such extremes of physical conditions within individual, readily resolvable objects with well-defined molecular gas irradiation geometries make PNe fertile ground for dramatically improving our understanding of photon-dominated regions and X-ray-dominated regions, such as are found in a diverse array of astrophysical environments. We propose ALMA molecular line mapping surveys of three archetypes of the class of extreme bi-lobed/pinched-waist, molecule-rich, high-excitation PNe (NGC 2440, 2818, and 2899). The results will provide unique insight into the role of high-energy irradiation in driving molecular gas heating and composition, and shed new light on the process of rapid, collimated mass loss in PNe descended from relatively massive progenitors. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR), HII regions | ISM and star formation | 2023-03-28T21:02:32.000 |
| 1050 | 2019.1.00233.S | 216 | Pinpointing dust-enshrouded star-forming regions within young proto-cluster galaxies at z=2.16 | Our recent narrow-band H-alpha study of a rich proto-cluster at z=2.16 (PKS1138-262) with Subaru Telescope revealed that star-forming (SF) galaxies in the proto-cluster environment are significantly more massive and more actively forming stars than general field galaxies. Those massive SF galaxies in young forming clusters are believed to be the progenitors of massive cluster spheroids in the local universe. We here propose ALMA Band-7 (870um) observations of 24um-detected, massive H-alpha emitters in this proto-cluster environment to spatially resolve their dust continuum emission on ~kpc scale (comparable to the HST rest-UV data available in this field). Our goals are (1) to identify dusty SF clumps inside the galaxies and pinpoint the location of most intense starbursts (hence rapid stellar/bulge build-up) within young cluster galaxies; and (2) to unveil the nature and environmental dependence of individual SF clumps by comparing our sample with those of general field galaxies at the same redshift obtained through our successful ALMA programs in the previous cycles. This program was approved twice (Cycle-3+4), but the observation was not carried out successfully. | Starburst galaxies, Galaxy Clusters | Active galaxies | 2021-02-28T20:28:20.000 |
| 1051 | 2017.1.00916.S | 111 | Outflows and infalling profiles in compact clumps: high-mass star formation in the Southern Outer Galaxy | We propose ALMA band 7 observations of 9 compact clumps in the outer Galaxy, associated with bipolar molecular outflows, at distances between 2 and 8 kpc. The sources are identified in our sample of HiGAL compact sources, and associated dense gas detected in CS(2-1). The sources present signposts of high-mass star formation in advanced evolutionary stages (massive young stellar objects and UCHII regions). Outflow emission was identified with APEX-2 observations at a resolution of 19", and additional SiO observations at 217 GHz confirm the presence of shocked gas. We aim to characterise the outflow emission and velocity gradients of infalling material in spectra profiles at resolutions of 1.1 arcsec, up to 19 arcsec. The results will be compared with our previous ALMA results in the young molecular outflow / hot core G331.512-0.103. The proposed targets are among the most luminous sources found outside the solar circle, and constitute an unique laboratory for the study of complex molecules in the outskirt of the Galaxy. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2019-05-31T13:11:38.000 |
| 1052 | 2019.1.00769.S | 10 | Benchmarking 13C fractionation with HC3N in protoplanetary disks | Isotope ratios (e.g. D/H, 12C/13C, 14N/15N, etc.) are particularly useful tools in the study of bodies within Solar System, shedding important light on topics such as the origin of the Earth's water reservoir. Attempting to connect these measurements to protoplanetary disks has proven difficult, however, with isotope fractionation studies limited by a poorly constrained 12C/13C ratio. A standard ratio of 70 is often assumed, but disk chemical modeling has shown that this value can be modified by factors of >5 by in-situ chemistry. Typical bright tracers (e.g. CO, CS, CS) are too optical thick in their 12C isotopologues to make a direct measurement, and weaker species do not have strong enough 13C isotopologue emission. A recent bright detection of HC3N toward TW Hya suggests that we may have found a tracer species, as the line is not particularly optically thick (tau~0.7). We propose to detect the 13C isotopologues of HC3N, obtaining the first direct constraint of the 12C/13C ratio in the planet-forming region of a protoplanetary disk. These results will have a broad impact on the disk community, immediately improving previous D/H and 14N/15N fractionation constraints. | Disks around low-mass stars | Disks and planet formation | 2022-07-13T21:51:59.000 |
| 1053 | 2023.1.00045.S | 0 | Measuring the Star Forming Potential of the Galactic Bar Dust Lanes | The dust lane features within the Galactic Bar are thought to mediate the flow of material from the Galactic Disk towards the Galactic Center, fueling the extreme environment found within the Central Molecular Zone (CMZ). Therefore, the study of galaxy bars is important for our understanding of how galaxies evolve and investigating the initial conditions of the gas before it accretes into the CMZ. The midpoint of the Dust Lanes (M4.7-0.8) was recently observed using the GBT, targeting the lower transitions of non-metastable NH3 lines - a dense gas tracer. These observations revealed multiple dense substructures with the cloud - indicating the cloud could be rich with dense gas, similar to clouds in the CMZ. Here we propose to target several dense gas tracers at the midpoint of the Dust Lanes (M4.7-0.8) that are abundantly detected in the CMZ and were recently detected in the ALMA ACES program. We use a similar spectral setup as ACES to address the question: How do the physical, chemical and dynamical properties of star-forming regions in the Galactic Bar Dust Lanes differ from those in the disc and Galactic center? | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-03-20T12:21:05.000 |
| 1054 | 2022.1.00750.V | 0 | A Multicolor View of the Black Hole Environment in M87 | Recent Event Horizon Telescope (EHT) observations of M87 have revealed a ring-like structure near the event horizon at 230 GHz. This structure was interpreted as a photon ring surrounding a dark shadow caused by gravitational light bending and the photon capture at the event horizon. However, the origin of the ring needs to be better understood. Photons that are not entirely bound by black hole gravity, such as the emission from plasma located further away from the photon capture radius, may also contribute to the observed ring. The recent GMVA+ALMA observation of M87 in Cycle 5 at 86 GHz indicates that a ring-like structure may exist in the core of M87 at this frequency as well. Here we propose new GMVA+ALMA observations of M87 in Cycle 9, when EHT+ALMA observations at both 230 and 345 GHz are expected to be performed for the first time. These observations will provide a multicolor (3.5, 1.3, and 0.9 mm) view of the black hole environment in M87, allowing us to investigate the origin of the ring, the physical properties of plasma in the innermost accretion flows and jets, and the magnetic field structure and Faraday rotation of the ring. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 3000-01-01T00:00:00.000 |
| 1055 | 2015.1.00200.S | 18 | Disk/Envelope of the Burst Source EX Lup | EX Lup is the prototype of EXor outburst accretion objects. The outburst trigger is not well understood, largely because of restricted information regarding the compact circumstellar disks. We propose to obtain 0.3 resolution ALMA molecular line emission images of C18O, 13CO, 12CO (J=2-1, v=0) and 13CO(2-1, v=1) from EX Lup. We will measure the accretion disk and envelope structure with the main CO isotopologues, while 12CO data probes if a molecular outflow has emerged as a result of the recent outbursts. We will derive disk mass and kinematics, and constrain the properties of any remnant envelope and outflow. The vibrationally excited line, may be thermally excited during the outburst and will yield information regarding the temperature structure in the disk. This first mass and dynamical measurements of an EXOr system will provide unique constrains to resolve the nature of the outbursts. | Disks around low-mass stars | Disks and planet formation | 2017-12-22T09:26:16.000 |
| 1056 | 2023.1.01532.S | 0 | Establishing HF as a robust molecular outflow tracer for high redshift galaxies | We propose to establish HF as a robust molecular outflow tracer in luminous star-forming and active galaxies at high-z. HF is the most sensitive sub-mm absorption line molecular gas tracer in galactic sightlines and has successfully traced molecular outflows in star-forming and active galaxies at low and high-z. Blue-shifted molecular absorption lines have proven to be sensitive and reliable tracers of cool gas outflows at high-z where emission line high-velocity wings become difficult to detect and disentangle. The OH+ and OH 119µm absorption lines are the two most utilised lines, tracing predominantly neutral and molecular gas phases, respectively. For studies aiming to measure the impact of the outflow on the galaxy, it is imperative to trace the full cool gas phase (atomic+molecular), which dominates the mass and momentum of the outflow. Thus a combination of the two lines is desirable. Unlike OH+, however, OH 119µm is too high frequency to be used at the peak of star-formation and blackhole activity (and outflows) in the universe Cosmic Noon, with current instruments. Thus a new molecular tracer needs to be established and here we propose HF as the most suitable candidate. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2025-03-16T14:52:49.000 |
| 1057 | 2018.1.01869.S | 40 | Tracing Shock Chemistry in Luminous IR Galaxies: Spatially Resolved Shocks in Extreme H2 Emitters | Local luminous infrared galaxies are dust-enshrouded, molecular gas-rich, intense starbursts that are usually inspired by major mergers. Lirgs thus provide an ideal place for an in depth look at the effects of mergers on the interstellar medium (ISM), specifically feedback from merger-driven star formation in the form of shocks. We select a sample of LIRGs that have a so-far unexplained excess of warm molecular hydrogen as revealed by Spitzer mid-IR spectroscopy. The IR data suffer from poor spatial and spectral resolution while optical observations have difficulty probing the dense and dusty ISM. ALMA provides the best tool for uncovering shocks in these dusty starbursts and for probing the shock chemistry to determine the extent, power, and dynamics of the shocked molecular gas. We propose to map these excess H2 emitters in the shock tracers/diagnostics SiO, CH3OH, and HNCO to look for evidence of shocks/outflows and to determine the scale of their contribution to heating the ISM. We will also map the shock tracers SiO and methanol (CH3OH) to diagnose strength, speed, and kinematics of any observed shocks and ultimately to determine the source of the shock. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2021-01-03T16:20:49.000 |
| 1058 | 2015.1.01539.S | 194 | A survey of prestellar, high-mass cluster-forming clumps: constraining models of high-mass star formation | The lack of a significant amount of prestellar, high-mass cluster-forming clumps has made hard to conclusively refute or support models of high-mass star formation. In addition, the insufficient sensitivity and angular resolution have done challenging to unambiguously test observational predictions. For this proposal, we have carefully selected a sample of massive clumps in the earliest stages of evolution (dark at 70 um). With ALMA, we will mosaic these clumps and recover the missing flux with ACA to: look for high-mass cores, determine their virial parameters and search for low-mass cores. Because the large sample of clumps in this proposal, we expect to detect more than a 100 cores. Thus, we will draw difinitive conclusions on which model of high-mass star formation better represent the observations in a statistical way. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-10-12T00:00:00.000 |
| 1059 | 2021.1.01676.S | 236 | A CO census of high-redshift submillimetre galaxies in ECDFS | Observations of redshifted CO in distant sub-mm selected galaxies (SMGs) probe the physical conditions in which new stars form. When CO is collisionally de-excited from the Jth to the J-1th rotational energy level, the result is a photon whose frequency is J*115GHz. The ground-state CO(1-0) line is perhaps the most direct tracer of the total molecular gas mass in galaxies, via the alpha_CO conversion factor. However 1-0 is observationally expensive to obtain, and thus most molecular gas surveys target higher-J lines (e.g. 3-2), which are brighter and redshifted to more favourable atmospheric windows. Such surveys must be down-converted to 1-0 via an assumed CO spectral line energy distribution (SLED) in order to measure total gas masses. No such template yet exists in SMGs, and as a result template SLEDs from low-redshift ULIRGs are often used, introducing large uncertainties in the derived properties of SMGs. This survey aims to conduct the first reliable CO SLED survey, using a sample of unlensed SMGs which benefits from the foundational bedrock of 1-0 data. Our aim is to construct the template SLEDs by which future observations of the ISM in high-z galaxies will be interpreted. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2023-01-11T15:41:29.000 |
| 1060 | 2016.1.00562.S | 13 | Measuring star formation rates in the dusty starburst galaxy NGC 1808 using mm recombination lines | The compact circumnuclear starburst in NGC 1808 has one of the highest infrared and radio fluxes of any starburst in the southern sky and is therefore an ideal case for comparing and calibrating star formation metrics. We propose to observe the H40alpha and H42alpha recombination line emission and the free-free 84.7-100.4 GHz continuum emission from the heavily obscured photoionized gas in this starburst. The results will produce star formation rates with accuracies of ~10% that can then be used to recalibrate infrared and radio star formation metrics. The results from this galaxy can then be used to measure more accurate star formation rates for other compact starbursts in both the nearby and more distant universe. | Starbursts, star formation | Active galaxies | 2018-04-10T13:45:20.000 |
| 1061 | 2019.1.00811.S | 29 | Cold Gas Around Black Holes: Fueling and Feedback in Galaxy Mergers | We propose to obtain very long baseline observations of CO(2-1) to measure the distribution and kinematics of cold molecular gas in the central few hundred parsecs of three outflow host galaxies, IRAS F17207-0014, III Zw 035, and IRAS F01364-1042. Our adaptive optics integral field spectroscopy has identified two key features within the nuclei of these galaxies: collimated warm molecular outflows and central dynamical masses up to 50 times larger than those predicted by black hole scaling relations. Only ALMA can provide the resolution-matched molecular gas observations needed to measure the temperature distributions and mass-loading factors of these confirmed nuclear outflows, a fundamental question regarding central engine feedback in galaxy evolution. The large central dynamical masses measured from our AO observations may be identifying a large mass of gas that will eventually fuel the black hole or be entrained in a molecular outflow. Our proposed observations will therefore either confirm some of the most extreme black hole scaling relation offsets or identify systems poised to undergo a massive central AGN accretion or starburst event. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2021-07-09T00:00:00.000 |
| 1062 | 2016.1.01408.S | 0 | The Cool Alter Ego of the Solar Corona | Thermal instability is a fundamental mechanism at work throughout the universe and has detailed observational consequences in the Sun. In particular, coronal rain (rapidly occurring plasma at coronal heights with chromospheric properties, i.e. partially ionised cool and dense) is the direct observational consequence of thermal instability in the solar corona. Increasing observational and numerical evidence suggest that its characteristics such as its thermodynamic state, the occurrence frequency and mass fraction in the corona, its morphology and dynamics are intrinsically linked to key aspects of the solar atmosphere and, in particular, to coronal heating. Thanks to its chromospheric nature, coronal rain is a unique ALMA observable produced in coronal loops, the basic building blocks of the solar corona. On the other hand, ALMA is unique in being able to firmly characterise the thermodynamic state and amount of coronal rain in the solar atmosphere. By investigating coronal rain with ALMA we aim at measuring the thermal inhomogeneity of the solar corona, thereby providing powerful constraints for coronal heating mechanisms and characterising the cool alter ego of the hot corona. | The Sun | Sun | 2018-11-14T00:00:00.000 |
| 1063 | 2021.A.00006.S | 30 | Spectroscopic confirmation of a strongly lensed star at z=6 | Three individual strongly lensed stars have been recently discovered at z~1, offering us new hope of directly observing individual starts at cosmological distances. Here we propose ALMA observations of the most highly magnified galaxy at z=6 so far known hosting a strongly lensed star candidate, dubbed LSz6. For the past few years, LSz6 has been steadily magnified by a factor of ~9000 on the critical curve directly between multiple images of a bright star-forming clump. The clump is also remarkable as the most distant known bound massive star cluster, with a radius <6 pc, the size of local star clusters. However, this lensed system is not spectroscopically confirmed. The purpose of this DDT request is to obtain the spectroscopic redshift of this intriguing system by scanning the Band 6 frequency range. Once the redshift is confirmed, we will establish the first unique laboratory of the individual star and massive star cluster at the epoch of reionization. This will enable follow-up observations in ALMA cycle9 and JWST cycle2 for their detailed characterizations, which leads to understanding the source of the cosmic reionization and the emergence of the first stars in the universe. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2022-09-30T12:50:22.000 |
| 1064 | 2016.1.00133.T | 703 | An ACA N+ survey of z=3-7 DSFGs from the South Pole Telescope survey | The South Pole Telescope (SPT) has detected at 1.4mm, ~100 bright (lensed), high redshift star forming galaxies from a 2500 degree^2 survey, with APEX/LABOCA and Herschel/SPIRE followup. For an unbiased subsample of 57 sources, we now have CO and [CII]-derived redshifts from ALMA Band-3 spectral scans, and APEX [CII] followup. We propose to measure the [NII] line in all 42 of these DSFGs lying at z>3, which have their [CII] lines measured (or being measured) by APEX, and can be reached in ALMA bands 6 or 7. These observations optimally use the ACA to get total flux N+ measurements for precision line ratios, and will provide a legacy database of the evolving distribution of C+/N+ from z=3-7 in a well characterized and unbiased sample of lensed DSFGs. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2017-11-19T02:48:32.000 |
| 1065 | 2018.1.01114.S | 171 | The Historic Apparition of Comet 46P/Wirtanen: Unprecedented Close-Up Analysis of Coma Composition and Physics | Cometary ices are believed to have been relatively unaltered since the birth of the solar system, and their compositions provide a unique record of ice chemistry in the protosolar disk midplane. The December 2018 apparition of comet 46P/Wirtanen provides a rare opportunity to observe a Jupiter Family Comet (and likely future mission target) at extremely close geocentric distance (~0.1 au). We propose to map the strong emission lines of HCN, H2CO, CH3OH and CS at unprecedented (18-28 km) spatial resolution using ALMA, while the extended-flux sensitivity of ACA will permit a full mm-wave chemical inventory including HNC, HC3N, CH3CN, NH2CHO, SO2, SO (plus dust/debris continuum). This will enable a deep exploration of the physical and chemical state of the inner coma, including 3D outgassing/jet morphology, kinematics and coma parent/daughter distributions and mixing ratios. These observations will advance our knowledge of primitive Solar System materials, and form an integral part of the multi-wavelength campaign to characterise 46P in support of future rendezvous missions. | Solar system - Comets | Solar system | 2019-12-11T17:24:34.000 |
| 1066 | 2018.1.00051.S | 68 | A comprehensive study of methanol aborption toward PKS1830-211 | We propose a comprehensive study of methanol in the unique z=0.89 molecular absorber toward PKS1830-211 by observing the strongest absorption lines of the molecule across ALMA bands. Methanol is the best probe of the cosmological invariance of the proton-to-electron mass ratio (mu) and PKS1830-211 is the sole intermediate-to-high-z source where methanol has been detected. Current constraints of mu-variation reach Delta_mu/mu < 6x10-7 (at 3 sigma) in this system but are affected by systematics. The new high signal-to-noise ratio ALMA observations will allow us to perform a multi-transition analysis and determine the physical and chemical conditions of the methanol gas. We will reach a limit of mu-variation similar or better than the best current limit, but with a robust handling of systematics related to methanol excitation, frequency-dependent continuum morphology, and time variability. | Damped Lyman Alpha (DLA) systems | Cosmology | 2020-11-23T02:51:54.000 |
| 1067 | 2015.1.01506.S | 35 | RW Aurigae: Probing the Aftermath of an Eccentric Star-Disk Fly-By | We propose observations of RW Aur, a young binary system thought to recently have gone through a close encounter of the two stars, which stripped away part of the primary's disk, resulting in a large tidal tail. We will test the fly-by model (which our group has extensively modeled) by measuring the structure of the tail, determining if it forms a kinematically coherent structure with the primary's disk, and searching for predicted asymmetries in the primary disk, which will be spatially resolved for the first time. In addition, we may be able to detect the secondary's disk (which may have been disrupted by the putative encounter), and we will search for other interesting chemistry and spatial structure that may appear in these observations, which will be much more sensitive than previous mapping of this system. | Disks around low-mass stars | Disks and planet formation | 2018-04-10T18:10:15.000 |
| 1068 | 2017.1.00093.S | 896 | Evolution of molecular clouds associated with O-type YSOs in giant molecular clouds in the LMC | This proposal aims at observing the brightest 40 high-mass YSOs, whose luminosity is a few 10^4 to 10^6 Lo, in the Large Magellanic Cloud in order to investigate the evolution of high-mass protostars in terms of the properties of the surrounding material. Our Cycle 1 observation toward N159W/E detected many features related to high-mass star formation; molecular outflows detected in 12CO(2-1), an indication of cloud-cloud collision as a formation mechanism of high-mass YSOs, the dense gas dissipation, the detection of radio recombination lines, and so on. These are thus found to be good tracers of the evolutionary status of high-mass YSOs and of the effect of the YSOs to the surrounding environments. The target lines we use are 12CO(2-1), 13CO(2-1), C18O(2-1), 13CO(1-0), C18O(1-0), CS(2-1), SiO(5-4), H30alpha, and H40alpha as well as in continuum in Band 6 and Band 3. Analysis of the proposed gas/dust data in combination with our expert knowledge of the LMC's high-mass YSO population and molecular gas distribution on larger scales will allow us to identify the conditions that lead to high-mass YSO formation and estimate the dissipation timescale of the progenitor clouds. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2019-11-19T18:19:13.000 |
| 1069 | 2015.1.00295.S | 11 | AGN Feedback in Action: Zooming in on the Molecular Outflow in the Nearest Active Galactic Nucleus | Galactic winds are essential to feedback processes that quench star formation and limit the total mass of large galaxies. However, they are poorly understood due to a lack of observational evidence, particularly in the molecular phase. In ALMA Cycle 2, we succsessfully detected the AGN-driven molecular wind in Circinus, constraining the molecular mass of the outflow, velocity, and general morphology. However, these observations are limited in resolution, rendering follow-up observations necessary. With 2.5 additional hours (including overheads) in Cycle 3, we will obtain a factor of 7 improvement in beam area to resolve structure on 25 pc scales - crucial to demonstrating interactions with the ISM. We will create detailed kinematic models of the wind, essential to determining whether molecular gas leaves the galaxy and if/when/where it is reaccreted to fuel future star formation. | Galactic centres/nuclei | Active galaxies | 2017-04-29T21:22:58.000 |
| 1070 | 2017.1.01523.S | 37 | Catching a Low-Mass Core in the Act of Fragmenting | We have discovered a new dense core in the Perseus Molecular Cloud with CARMA. This core, which we call L1451-west, appears to be starless with hints of sub-structure in follow-up ALMA ACA continuum data; this suggests it is on the verge of forming one or more low-mass protostars or brown dwarfs. Observing a starless core in the early fragmentation stage is extremely rare and will help test models of turbulent fragmentation and protostellar/proto-brown dwarf multiple formation. We propose ALMA 12-m+ACA observations of 1 mm continuum to resolve the continuum emission within L1451-west with high signal-to-noise to confirm the tentative detection of sub-structure, and observations of N2H+(3-2) to study the structure and kinematics of the dense gas. These observations will help determine the true nature of this interesting starless core and advance our overall understanding of the earliest stages of the star formation process. | Low-mass star formation | ISM and star formation | 2020-06-21T00:00:00.000 |
| 1071 | 2023.1.00305.T | 0 | First Light of Nearby Supernovae: Disclosing the Massive Stars' Final Activities | Recent observations of core-collapse supernovae (CCSNe) have led to a surprising picture that the massive stars are much more dynamic in the last few years than widely accepted previously; dense circumstellar matter confined in the vicinity of the progenitor (confined CSM) has been inferred. However, the optical emission is biased to pick up extreme CSM with large uncertainty in the interpretation. A quick ALMA ToO will yield unique and unbiased diagnostics. There are only three previous examples for which the nature of the confined CSM has been derived, using the ALMA data within ~5 days since the explosion. Contrary to the previous expectation that the confined CSM is common, a striking diversity has been emerging, but the very small sample does not allow further investigation. Inspired by this proof-of-concept, we propose ToO observations of two CCSNe at Bands 1, 3 and 6; one SN from a compact He or C+O star and another SN from a giant progenitor. This will allow us to study whether the final activity is dependent on the nature of the stars. This project will bring us new and robust information on the yet-unclarified final evolution of massive stars. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2025-01-27T01:23:31.000 |
| 1072 | 2021.1.01137.S | 50 | Resolving Planet Suppression in Circumbinaries During the Disk Hosting Phase | Intermediate mass stars are more likely to be part of a binary or multiple system than solar type stars. Binarity appears to affect the frequency of exoplanets; detected exoplanets in circumbinary systems are increasingly unlikely at short radial separations from the binary. Here the influence of the central hosts on the inner disk is thought to suppress planet formation. We propose high resolution observations of bright, circumbinary disks. We target circumbinaries around intermediate mass stars asthey have more massive disks than lower mass counterparts, in order to identify the mechanisms by which planet suppression takes effect during the disk hosting phase. We target close (a<10 au) binaries hosting circumbinary disks to guage the extent to which the central binary pair imacts planet forming regions in the disk through depletion of planet building material and the alignment of inner disk regions relative to the binary pair. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2022-11-22T19:54:05.000 |
| 1073 | 2015.1.01013.S | 42 | Physical Properties and Submillimeter Exccess in low metallicity clouds in the Magellanic Bridge | The Magellanic Bridge is a filamentary structure of about 15 to 21 kpc seen in neutral hydrogen (HI) lying between the LMC and the SMC. It represent the nearest tidally interaction between these two galaxies some 200 Myr ago. It hasa lower metallicity than the SMC and therefore allow to study the ISM in extreme conditions. Recent studies have revealed the presence of young (< 200Myr) massive stars and CO molecular clouds. The latter are barely resolved in single-dish observations and are spatially related to warm dust emissionsources, as recently established by the Spitzer SMC-SAGE and Herschel HERITAGE studies. We have obtained 870 micron images of three these sources in the Magellanic Bridge. Surprisingly, their dust emission shows a large submillimeter excess indicative of either very cold dust or a dramatically different submillimeter emissivity. Source A was observed in ALMA c1 and shows an excess at 1mm and several CO cores. We propose to study two additional sources in CO(1-0) and (2-1) and the associated continuum at arcsecond resolution to determine the physical properties of molecular cloud which are in a different evolutionary stage than Sourcce A. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2020-10-12T00:00:00.000 |
| 1074 | 2015.1.00734.T | 23 | Exploring the nature of relativistic jets in neutron star X-ray binaries - Part 2 | We propose to observe the mm-frequency emission associated with relativistic jets in a transient neutron star X-ray binary to determine for the first time its evolution during a single outburst. This observation will allow us 1) to determine the size of the jet emission region close to the neutron star without contamination from X-ray reprocessed emission from the disc or from the companion star in the X-ray binary, thereby constraining jet production mechanisms, and 2) to study the evolution of the region where the particles are accelerated in the jets of neutron stars in different accretion states and compare it to that found in black hole transients. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2018-04-19T00:00:00.000 |
| 1075 | 2019.1.01008.T | 31 | Direct sublimation vs. gas-phase synthesis: A Comet TOO proposal | Comets contain ice, dust and debris left over from the formation of the Solar System. Having remained in a relatively quiescent state ever since, their compositions provide unique insights into the thermal and chemical properties of the protosolar disk and prior interstellar cloud. Detections of complex organic molecules in cometary comae are becoming routine using single-dish mm-wave observations, but the common assumption that these species originate in the cometary ice is largely untested. Our latest chemical/hydrodynamic coma models point to gas-phase chemistry as a possible origin for some of these species. We propose to use ALMA to map the distributions of HC3N, NH2CHO, CH3CN and other molecules (including known extended source species) in a bright target-of-opportunity comet, to reveal whether these species arise directly from the sublimation of cometary ice or whether they are instead synthesized as products of gas-phase chemistry in the coma. In case of only a faint comet in Cycle 7, we will focus on mapping the distributions of H2CO, HNC (and other abundant species) to elucidate the nature of their extended coma sources and compare to previous (limited) mapping results. | Solar system - Comets | Solar system | 2021-04-06T19:02:59.000 |
| 1076 | 2019.2.00164.S | 20 | Water as a tracer of the ISM conditions in high-z active galaxies: A pilot study on hot dust obscured galaxies. | Water is the third most abundant molecule in galaxies, after CO, and in recent years it has proved to be a valuable tracer of the ISM conditions in low redshift galaxies. Up to now the high redshift detections have been few and limited to lensed sub-mm galaxies, but in our recent ALMA observations of two hot dust obscured galaxies (HotDOGs) we serendipitously detected water transitions. Here we propose a follow up on these sources, targeting three different water transitions, the combination of which will help identify the different components of the ISM. HotDOGs are ideal for such a study, as they are going through intence star-formation and BH growth, with high levels of obscuration. They have been proposed to represent the transitional phase between the starburst and quasar phases of popular galaxy evolution models. This pilot study will allow us to demonstrate the power of using water as a molecular gas tracer at high-z, and will allow for the design of representative future studies. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2022-10-05T18:11:55.000 |
| 1077 | 2017.1.00795.V | 0 | Imaging the Global Accretion and Outflow of Sgr A*: 3mm VLBI with GMVA+ALMA | The Galactic Center supermassive black hole, Sagittarius A* (Sgr A*), is the most promising target to study the dynamics and thermodynamics of black hole accretion and outflow via direct imaging. At 3.5mm, the emission from Sgr A* occurs within ~15 Schwarzschild radii of the black hole and is resolvable with the GMVA, but previous observations have had insufficient sensitivity and baseline coverage to study its detailed structure and evolution. We request two full-polarization GMVA+ALMA observations at 3.5mm, to complement our awarded 2017 observations. These observations will elucidate the long-standing question of whether the 3.5mm emission arises in an accretion disk or in a jet, they will be sensitive to intrinsic structural variability on timescales of hours, days, and a year, and they will provide critical guidance to interpret Event Horizon Telescope images on scales of only a few Schwarzschild radii. | Galactic centres/nuclei | Active galaxies | 2021-05-21T00:00:00.000 |
| 1078 | 2015.1.00598.S | 106 | WISDOM: CO Imaging of SMBH Mass Measurement Candidates | Ubiquitely present at the centres of galaxies, supermassive black holes (SMBHs) are key to understand galaxy evolution. However, the SMBH mass-central velocity dispersion relation driving most theoretical efforts is based on a relatively small number of measurements and only a handful of methods. Our recent work has shown that it is straightforward to dynamically estimate the mass of SMBHs, by simply probing the near-Keplerian rotation of molecular disks around them at high angular resolution. In the ALMA era, this can yield hundreds of measurements in galaxies of all morphological types. As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM), we have already identified numerous promising targets, bright in CO and with regular nuclear dust distributions. In this proposal, we request moderate spatial resolution (0.5") CO(2-1) imaging of these targets, to weed out galaxies with perturbed (or absent) central molecular gas, and thus identify the best targets for follow-up SMBH mass measurements at high spatial resolution. We have 10 targets across the Hubble sequence, and all will lead to exciting ancillary science irrespective of future SMBH mass measurements. | Surveys of galaxies, Galactic centres/nuclei | Galaxy evolution | 2017-07-29T15:21:17.000 |
| 1079 | 2022.1.00917.S | 0 | THAURES: THousands of AU RESolution study of the CMF in the LMC | We propose to carry out the highest resolution (2500 AU) observations in an external galaxy ever performed to date, in order to characterize the smallest star-forming structures observed within one of the most iconic star-forming regions, namely 30 Dor-10 in the very nearby (50 kpc) Large Magellanic Cloud (LMC). The exquisite sensitivity we request (10 micro-Jy/beam), only accessible with ALMA, will allow us to resolve the mass distribution of detected cores down to 1 solar mass and probe the Core Mass Function (CMF) for the first time in an external galaxy with parameters comparable with the well studied CMF in the Milky Way. These observations will have a large impact and they will be a signature result for ALMA, producing the first milliarcseconds thermal dust image of one of the most famous star-forming region in the sky. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2024-12-19T21:35:36.000 |
| 1080 | 2016.1.01367.S | 31 | The onset of collapse in a chemically young pre-stellar core | Prestellar cores are believed to be the immediate precursors of protostars, but how and why they collapse remains poorly understood. The respective roles of magnetic support, turbulent support, or external agents in triggering this collapse are not known. To shed light on this issue, the inner properties of prestellar cores (density profile, temperature, kinematics) must be characterised, yet so far the relatively coarse spatial resolution has prevented us from determining their structure on scales most relevant to the star forming process, i.e. smaller than 1000 AU. L1689B is a chemically young prestellar core showing near-sonic infall motions over a few thousand AU, providing a unique target for such studies. Detailed modelling of both the continuum and line emission indicates that the source is likely a factor of 5 denser than Herschel data indicate, and thus show that it is just entering star formation. We propose to use the ACA to map L1689B at spatial resolutions < 1000 AU in N2H+(3-2) at 280 GHz to characterise infall motions and in the continuum to derive the density and temperature structure on small scales, thus enabling us to probe the region where star formation occurs. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-07-08T05:10:00.000 |
| 1081 | 2013.1.01332.S | 1 | Dense Gas and Star Formation in Interacting Galaxy Pair NGC 4567/8 and Comparison to Galactic Dense Cores | In order to determine the state and physical conditions of the dense molecular gas and its relation to the physics of star formation across infrared bright interacting galaxy pair NGC 4567/8 from the VIRUS-P Investigation of the eXtreme ENvironments of Starbursts (VIXENS) survey, we propose to use ALMA to obtain spatially resolved maps of HCN, HCO+, HNC, and CCH gas. We will compare the ALMA dense gas maps at matched spatial resolution to our resolved VIRUS-P integral field unit maps, and a full suite of multi-wavelength ancillary data (CO/HI maps, GALEX, Spitzer, Herschel, and HST). We will also compare the dense gas distribution in this interacting pair to a sample of Galactic high mass star forming dense cores in the same gas tracers. Understanding the physics of star formation and its relation to the dense gas content in a low-z merger and comparing to Galactic star forming regions is paramount to understand ALMA observations of high-z galaxies merging systems. Obtaining spatially resolved maps of multiple tracers of dense gas in nearby galaxy mergers is only now possible thanks to the combination of spatial resolution, sensitivity and UV coverage offered by ALMA in cycle 2. | Merging and interacting galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2016-08-26T12:36:44.000 |
| 1082 | 2018.1.00437.S | 282 | How early on does planetesimal formation take place? | We propose to provide fundamental constraints on the timing of planetesimal formation by searching 30 class III (supposedly diskless) stars in the 2-3Myr Lupus star forming region for dust emission at debris disk levels (0.024Mearth). Such stars comprise 25% of the population and must be those that had relatively short-lived protoplanetary disks. The resulting debris disk fraction will be compared with 7% predicted from population models of older main sequence star disks, to determine if the planetesimal belts seen later on are already in place by 2Myr. A null detection would be 10sigma significant implying that planetesimal belts like AU Mic must be born in long-lived protoplanetary disks, while a detection rate >7% could indicate that planetesimal belt formation is ubiquitous (but some belts are later depleted by dynamical instability) or that protoplanetary disks persist at low levels. CO will help distinguish between a debris and protoplanetary interpretation. This would be the first survey to characterise the disk mass distribution in any star forming region down to debris disk levels, and is the logical next step from far-IR surveys and those of class II disks in the sub-mm. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2020-08-07T12:45:48.000 |
| 1083 | 2022.1.00794.S | 180 | The Spatial Scale of the Infalling Envelope at the Late Protostellar Phase | What determines the stellar mass is one of the most fundamental problem in the field of star formation. The similarity between Core Mass Functions (CMFs) and the Initial Mass Function (IMF) suggsets one-to-one mapping between core mass and stellar mass. On the other hand, recent observations imply that material is supplied from ambient gas surrounding the dense cores in some cases. To understand which scenario is correct and the origin of the IMF, determining the spatial scale from which protostars gain material during star formation processes is required. Here, we propose seven-pointing mosaic observations of Class I protostars to investigate the gas kinematics over a wide spatial range from ~1,000 to ~13,000 au. The science goal of this proposal is (1) to reveal a typical radius of the infalling envelope at the late protostellar phase and whether protostars gain material beyond radius of the initial dense core or not, and (2) to search for a universal radius of the infalling envelope normalized by a physical parameter of the protostellar system that may explain variety between systems. | Low-mass star formation | ISM and star formation | 2024-08-23T21:07:38.000 |
| 1084 | 2022.1.01108.S | 55 | Probing the Kinematics of Streamers | Our understanding of star formation has changed significantly since the initial theories were conceptualized. This is further evidenced by recent studies that have shown large-scale infall of material, called "streamers", falling onto disks around young stars. Streamers have the potential to influence disk structure and dynamics by creating misalignments or triggering gravitational instability, but their significance has not yet been assessed observationally. We request ALMA multi-pointing observations toward three sources that show clear evidence of streamers in archival ALMA data: GW Ori, SU Aur, and Elias 2-27. We will (1) image a more complete extent of the streamers beyond the current field-of-view, (2) compute the total mass enclosed in the streamers and mass infall rate, and (3) constrain the kinematics of the streamers. Together, the proposed observations will allow us to infer how significant a role streamers play in the evolution of protoplanetary disks and their planet-forming capacities. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2024-07-18T21:21:02.000 |
| 1085 | 2017.A.00047.T | 75 | AT2018cow: the poster-child relativistic explosion for high-frequency time-domain astronomy | AT2018cow is the nearest relativistic supernova in 20 years, and could be a new member of the rare class of low-luminosity GRBs. Five days after the initial optical discovery, we found a very strong detection at 230 GHz with the SMA, and initiated a nightly monitoring program. This is the first time a relativistic supernova has been observed so early at sub-millimeter wavelengths. Sub-mm observations offer a unique diagnostic, especially of the reverse shock, of relativistic blastwaves. There is an extensive worldwide campaign to observe AT2018cow across the electromagnetic spectrum. Given our bright sub-millimeter detection, this event also has the possibility to become a poster child for high-frequency time-domain astronomy. To complement our ongoing SMA monitoring campaign, here we request ALMA observations in Bands 6, 7, 8, and 9. The proposed ALMA observations, combined with our approved decimeter to centimeter ATCA observations, and the ongoing Swift X-ray monitoring, will fully capture the forward shock (the afterglow) and the reverse shock, thereby enabling us to measure the circum-explosion density, the blastwave energy, and the microphysics of this relativistic shock. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2019-01-26T16:12:54.000 |
| 1086 | 2018.1.00216.S | 30 | Quenching in action: gas reservoirs in a transitioning massive galaxy at z=3.71 | Determining why galaxies stop converting gas into stars is a key unanswered question of galaxy evolution. Multiple processes could play a role in quenching a galaxy, yet evidence is scarce to favor one explanation over the other. Using NIR spectra, we recently discovered quiescent galaxies in the first billion years of the Universe, with properties that models fail to predict. Studying these systems further is necessary to understand how quenching can occur so early, and rethink the models. Here we propose to characterize the gas reservoirs and formation history of "Hyde", a massive and extremely obscured yet moderately IR-luminous galaxy. A number of evidence indeed show that Hyde is a galaxy on the verge of quenching, and may in fact be already quenched: this is a unique laboratory to study the transition to quiescence. We thus propose to use ALMA to a) determine if Hyde is already quenched or still in transition; b) robustly measure its gas reservoir; and c) build a high-resolution map of the dust continuum to study its morphology and learn about its recent past. Combined, these data will give us unique constraints on the quenching paths of galaxies in the early Universe. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2021-01-07T09:57:38.000 |
| 1087 | 2016.1.00165.S | 61 | The Nearest Forming Massive Protostar, OMC1 Source I: Bloated Protostar, a Binary, or a Merger Remnant? | Orion Source I, the nearest high-mass protostar, was dynamically ejected from the OMC1 cloud core ~500 years ago, an event that triggered an explosive outflow. We propose long-baseline Band 3, 6, and 7 observations to obtain the highest spatial resolution images ever obtained in thermal lines and continuum of a massive protostar and its disk (0.08, 0.03, and 0.04). The sub-mm morphology and luminosity of Source I and its disk will be measured to see if it has a bloated photosphere, consists of a binary, or is a merger remnant. The properties of other embedded stars in the OMC1 core that may contribute to the luminosity and heating of the Orion KL nebula, along with the base of the explosive outflow originating from this region will be determined with unprecedented resolution. Below 200 GHz, the spectrum of Source I resembles an opaque blackbody. If the opacity is dominated by dust, sensitive 3 mm ALMA data may detect emission lines from the disk. These observations will lead to improved determinations of the stellar and disk masses, probe the disk structure, and shed light on its recent evolution. | High-mass star formation | ISM and star formation | 2019-06-05T00:00:00.000 |
| 1088 | 2022.1.01759.S | 20 | Pathway to Euclid: characterisation of a richness-complete sample of galaxy clusters | We here propose to use Band 3 ACA to obtain follow-up observations of a subsample of galaxy cluster selected in HSC observations as part of the Euclid preparation program. The main aim is to build a statistically complete sample of high richness clusters, allowing for a first exploration of any systematics in the determination of the optical observables, in the characterization of the miscentering distribution, and in the calibration of mass-observable scaling relations. These observation will therefore represent a critical step in the cosmological exploitation of the forthcoming Euclid mission. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2024-10-09T16:19:45.000 |
| 1089 | 2019.1.00840.S | 72 | The Host Galaxies of the Radio-Loud Quasars at z>5 | Quasars at z>5, i.e.<~1 Gyr after the Big Bang, host >billion solar masses black holes, and are found in already evolved, massive galaxies, of which a large fraction (~20%) are undergoing major merger events. ALMA observations of the cool gas and dust in these systems are key in such studies. However, the evidence built so far relies on samples of radio-quiet quasars only. Very little observational evidence is available to constrain the role of radio jets, whose interplay with the interstellar medium through "radio-mode" feedback is crucial in the evolution of massive galaxies and in the onset of galactic scaling relations, especially at high-redshift. Here, we propose to detect the [CII]/CO(6-5) emission line, and underlying far-infrared continuum, in the host galaxies of all the known z>5 radio-loud quasars observable from ALMA. We will study their physical properties, i.e. gas/dust content, star formation rates and morphology, and compare them with those of the available large radio-quiet quasar sample. Furthermore, we will assess whether high-z radio-loud quasars are ubiquitously found in the first protoclusters, as suggested by both theoretical and observational studies. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2021-04-06T22:19:55.000 |
| 1090 | 2013.1.00592.S | 2 | Forming giant planets: the initial conditions | We propose a comprehensive program to determine the structure of the outer region (> 20 AU) of protoplanetary disks around young A-type stars. The primary goal is to measure the gas and dust surface density structure. In turn, this will provide the radial variation of the gas-to-dust ratio as well as the total gas mass. This information is fundamental to understand the initial conditions of gas giant planet formation and make the link with directly imaged exoplanets around A-type stars. Despite its importance, we still do not know the total amount of the gas reservoir available to form planets in disks. Thanks to ALMA we can now use the faint, optically thin, emission of the rare CO isotopologues to address the gas reservoir and its radial distribution. We have selected a sample of nearby, isolated disks for which we have collected a large multi-wavelength data set that will complement the ALMA images. This program will have a legacy value for the whole community providing a unique benchmark for detailed disk modelling. | Disks around high-mass stars | Disks and planet formation | 2017-02-05T11:57:04.000 |
| 1091 | 2019.1.00933.S | 11 | Witnessing the molecular enrichment of the circumgalactic medium | We have discovered a remarkable 100-kpc structure around a compact starburst/AGN at z=0.5. The structure is a huge nebula traced by ionised oxygen, and resembles a limb-brightened bipolar bubble, driven by feedback from a central starburst or AGN. It is the largest and most luminous [OII] nebula yet observed. In this object we are gaining a rare insight into the deposition of metals/energy far into the circumgalactic medium (CGM). Our current ALMA observations reveal CO(2-1) emission linking the central galaxy to the wider nebula, implying that molecular gas is either being driven out of the galaxy or is cooling out of a hotter outflow. Key questions are (1) how far does the molecular component extend into the CGM? (2) how much mass does it contain? and (3) what are its properties? We will address these questions with new CI(1-0) and 13CO(2-1) observations, revealing the diffuse molecular gas and allowing us to assess the dynamical state of the cold gas phase. Linking the cold molecular gas phase to the more extended, warmer ionized outflow is crucial for a better understanding of the role the CGM plays in the baryon cycle of galaxies. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2022-10-25T17:25:31.000 |
| 1092 | 2018.1.01128.S | 193 | A unique test of the high-redshift baryon cycle: connecting molecular gas content and metallicity at z~2 | Molecular gas plays a key role in the cycle of baryons into and out of galaxies. In the local universe, a relationship between stellar mass (M*), molecular gas fraction (f_H2), and gas-phase metallicity (Z) is observed, reflecting the connection between molecular gas content, gas accretion, and feedback. We propose to search for this connection for the first time at high redshift, based on CO(3-2) measurements for 14 massive star-forming galaxies at z~2.3 selected from the MOSFIRE Deep Evolution Field (MOSDEF) survey. MOSDEF galaxies are characterized by rest-optical spectra and extensive multi-wavelength photometry, providing robust estimates of M*, dust-corrected SFR, size, and metallicity. The proposed CO(3-2) measurements will be used to derive molecular gas masses and f_H2. The unique combination of f_H2 and robust metallicity measurements for typical z~2 star-forming galaxies will enable us to search for a M*-f_H2-Z relation at z~2. The shape of this relation is a powerful probe of the cycle of baryons. Specifically, our measurements will provide unprecedented tests of feedback prescriptions in galaxy formation simulations and constrain the evolution of galaxy gas flows. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 2020-01-15T19:45:30.000 |
| 1093 | 2013.1.00601.S | 2 | ALMA measurements of disk turbulence | The amount of turbulence in proto-planetary disks controls both the disk evolution and the formation of large solids, which are the seeds for the formations of planets. We propose to image the proto-planetary disk around the young star HD 163296 in the 12CO, 13CO, and C18O J=2-1 transitions to measure the disk turbulent velocity across the entire vertical extent of the disk within the midplane CO snow line. We will study whether the most dense disk regions are quiescent or turbulent, and provide direct constraints to theoretical models for the disk viscosity. The proposed ALMA Cycle 2 observations have the potential to reveal the long-postulated MRI dead-zones which are expected to play a fundamental role in the formation and evolution of planetary systems. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2016-12-21T21:01:46.000 |
| 1094 | 2015.1.00815.S | 8 | Kinematics of Protostars at 200 AU: Completing the Evolution of Angular Momentum From Cores to Disks | Angular momentum determines the initial conditions for disk formation and has implications on the properties of multiple systems. We aim to better understand how angular momentum influences the scale for dynamical collapse, shapes the degree of fragmentation and separation in multiple systems, and provides constraints for numerical simulations. We propose to study the specific angular momentum in the inner envelopes of ten Class 0 sources at ~200 AU scales. By combining the ALMA measurements of specific angular momentum with two large surveys from the SMA and GBT, we will be able to trace the evolution of specific angular momentum from 20000 AU to 200 AU for the first time. Also, our sample of ten sources, which consists of six single systems and four binary systems, will allow us to investigate and compare the conditions in these two types of different systems. ALMA provides an unique opportunity to study the gas kinematics down to 200 AU scale with its unprecedented sensitivity, thus providing key information on the transition from envelopes to disks. | Low-mass star formation | ISM and star formation | 2017-08-18T15:56:08.000 |
| 1095 | 2017.1.01516.S | 54 | Water, water everywhere, Nor a drop to drink: Solving the riddle of the most luminous water emitters known | The source BRI 1202-0725 is a well studied group of galaxies consisting of an interacting pair of a QSO and a SMG, and a pair of Lyman-alpha emitters at z~4.7. The QSO and SMG, despite having intense star formation and a powerful QSO do not appear to be driving significant outflows in the dense molecular gas. If there are no outflows, then where does the energy injected into their ISM go? In cycle 3, we detected strong HF(1-0) and H2O emission, making the QSO and SMG the most luminous sources of water and HF emission known. To take advantage of the unique configuration of galaxies to constrain robustly the excitation mechanism of water, the water abundance, and the dissipation of kinetic energy in and heating rate of the dense molecular gas, we propose to observe 4 water lines. With the wealth of lines that have been observed, including CO, CI, [CII], will allow us to constrain how the star formation may be regulated in powerful starburst-AGN combinations where there is no significant evidence for vigorous outflows as is required in galaxy evolution models. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-01-22T15:34:02.000 |
| 1096 | 2019.1.00466.S | 30 | Probing [CII] Emission Associated with the First Sample of Strongest OI Absorption Systems in the Reionization Epoch | Intergalactic medium (IGM) metal absorption lines observed in z>6 QSO spectra offer the opportunity to probe the early galaxy feedback process, the nature of enriching sources and IGM topology in the reionization and post-reionzation era. Inspired by our pilot results, we propose to carry out the first statistical study of using ALMA Band 6 to observe a sample of four newly identified, strong OI absorbers at z>6. These four absorbers have largest column densities identified to date at z>6, selected from ~50 QSO sight lines. We will search for star-forming galaxies that could be sources of IGM metal enrichment. Our deep ALMA observations will detect [CII] emission and far-infrared (FIR) dust continuum of star-forming galaxies down to a [CII]-based star formation rate (SFR) of 10 M_sun/yr, and within the projected impact parameters of 60 kpc from the quasar lines of sight. Results from this program will provide the first sample of galaxy-IGM connection at z>6, the end of reionization era. The results will be able to compare in details with cosmological simulations of the IGM and test models of IGM enrichment through galactic outflows. | Sub-mm Galaxies (SMG), Damped Lyman Alpha (DLA) systems | Galaxy evolution | 2021-07-09T16:15:31.000 |
| 1097 | 2011.0.00099.S | 0 | Reformation of Cold Molecular Disks in Merger Remnants | It has been long predicted from numerical simulations that a major merger of two disk galaxies results in a formation of the spheroid-dominated early-type galaxy. Contrary to this classical scenario of galaxy merger evolution, recent high-resolution simulations that include more realistic gas physics have shown that not all of the major mergers will become an early-type galaxy, but some will reemerge as a disk dominated late-type galaxy. Here we propose to obtain sensitive and high resolution CO(1-0) maps toward 20 optically selected advanced merger remnants with well studied stellar hosts. The main purpose of this study is to identify the presence of molecular gas disks formed through a merger of two galaxies, and to examine the dependence on the stellar mass and structure in a statistically significant sample of merger remnants. We already have a tentative evidence that disk formation is common in merger remnants from our own analysis of archival interferometric data. If CO(1-0) is detected in all of the proposed sources, the new ALMA observations will triple the number of CO maps for a robust statistical analysis. | Merging and interacting galaxies | Galaxy evolution | 2013-08-24T09:30:00.000 |
| 1098 | 2016.1.00990.S | 78 | Spatially resolved kinematics and gas mass profiles of compact SFGs: Witnessing the key epoch of bulge formation | The discovery of the "red nugget" population (massive, compact, quiescent galaxies) at z = 2 indicates that early passive galaxies were remarkably compact compared to their present-day elliptical counterparts. Recent HST observations have identified a likely population of progenitors: similarly massive and compact galaxies that are dusty and star-forming. While several pieces of indirect evidence link these two populations, resolution and sensitivity limitations in optical/NIR observations prevent a direct confirmation. Only the unique capabilities of ALMA in the FIR can provide definitive confirmation of this evolutionary connection. We propose to obtain high spatial resolution (FWHM=0.12''), Band-4 CO and [CI] velocity maps on 4 dusty, compact SFGs at z~2 to answer the following questions: a) what are the kinematic properties of their molecular gas? (ordered rotation vs. large dispersion), b) is the molecular gas profile as compact as the stellar mass and SFR sizes (FWHM=0.2'' and 0.12''), c) do they have short quenching (gas depletion) timescales consistent with the rapid build up the quiescent population at z = 2? | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2018-09-06T04:08:15.000 |
| 1099 | 2022.1.00029.S | 1377 | The multiplicity of the sub-mm counterparts of far-infrared bright SDSS quasars | We propose ALMA band 7 continuum observations at resolution of ~0.8" of a statistical, FIR-bright sample of 153 1 | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-01-04T16:09:08.000 |
| 1100 | 2019.1.01701.S | 1 | Revealing the Debris Distribution in Two Rocky Planet Forming Disks | We propose high angular resolution ALMA maps to reveal the debris distribution in two young debris disks where significant disk variability and optical eclipsing events, likely due to the aftermath of large asteroid impacts, are observed. The ALMA images will provide crucial disk geometric information and constrain disk scale height and any asymmetric sub-structure in the disks. The proposed observations will also determine the gas content by sensitive CO measurements, and assess the dynamical and evolutionary state of these two rocky planet forming disks. | Debris disks | Disks and planet formation | 2022-09-28T14:47:09.000 |
| 1101 | 2017.1.00572.S | 70 | Weighing Low Mass Black Holes in the Nearest AGN | In ALMA cycle-3 we observed two low mass dwarf galaxies, aiming to make the first robust dynamical detections of ~10^5 solar mass central black holes. These measurements will provide constraints on the formation of black holes in the early universe, and on the physics underlying galaxy -- black hole scaling relationships. Our targets are two active galactic nuclei (AGN) at D < 5 Mpc, and both show clear evidence from near-infrared observations of rotating molecular disks surrounding their black holes. The high resolution of ALMA will enable us to significantly improve on existing black hole mass measurements of these galaxies. Unfortunately, however, we have been hampered by the lack of short baselines in the data obtained, and here we propose to use ALMA to obtain intermediate resolution observations of these targets. A short additional allocation of ALMA time is all that is needed to maximise the return from the time ALMA has already invested. | Galactic centres/nuclei, Dwarf/metal-poor galaxies | Active galaxies | 2019-10-09T07:40:58.000 |
| 1102 | 2015.1.00770.S | 21 | (Sub-)mm Continuum Emission and Gas Fueling in the Rare, Type-Transitioning Seyfert Mrk 590 | The recent disappearance of the optical broad emission lines in Mrk590 remains puzzling, casting doubts on the dominant AGN unification scheme where their presence depends only on source orientation. The fading of the radio to X-ray continuum fluxes suggests the AGN may be turning off. Studying such extreme behavior can provide the most profound insight on AGN fueling, accretion and outflows. Our Cycle 2 CO(3-2) maps reveal little molecular gas in the central 120pc. We discovered a central gas ring, where a component with disturbed kinematics may be fueling the center. The source of the 343 GHz continuum flux in the inner 120pc, likely to also be variable, remains unidentified. Our most urgent goal is to measure the spectral shape of the (sub-)mm continuum emission in the center to determine its physical origin; these are crucial baseline data for understanding possible flux variability should the central engine reignite or fade further. We maximize the science returns by concurrently observing the CO(1-0) and CO(6-5) lines to place even tighter constraints on the gas mass closer to the AGN, and better understand the fueling mechanisms (or lack thereof) in this intriguing source. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-09-09T20:18:01.000 |
| 1103 | 2023.1.00091.S | 0 | Putting to test the first hypothesized ALMA detections of a close stellar/planetary companion orbiting an AGB star | Asymptotic giant branch (AGB) stars represent the late evolutionary phase of ~95% of stars in our Milky Way. It is now thought that most of these stars have at least one planetary or stellar companion. But, the direct detection of close companions has proven to be challenging owing to the extreme characteristics of AGB stars, including pulsations and high luminosities. ALMA offers a unique opportunity to detect close companions around AGB stars. In the last decade, secondary point sources in the ALMA continuum data of 2 nearby AGB stars have been conjectured as being likely due to a close planetary or stellar companion. Here we aim to test these first hypothesized ALMA detections of a close companion orbiting an AGB star by examining the persistence and displacement over time of both gas and dust features. The data will allow to reveal the nature of the secondary point sources, and the mass and orbital period of the potential companion. The results will take a crucial step in understanding clumps and how planets and stellar companions survive the harsh AGB conditions and hold the exciting prospect of constraining the cause of the currently unexplained long secondary periods. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2025-08-19T13:14:16.000 |
| 1104 | 2016.1.01202.S | 59 | Resolving the sub-arcsec structure surrounding the AGB star R Leo | It is widely accepted that the Asymptotic Giant Branch stars (AGB) are variable stars that eject large amounts of processed matter to the Interstellar Medium during their pulsation. A fraction of this expelled matter forms dust grains that are accelerated by the stellar radiation field and drag the surrounding gas. This process is quite complex and still poorly unknown, partly because of the lack of observations with enough angular resolution to probe the surroundings of the central stars, where the ejection mechanisms mostly work. It is unknown if these mechanisms could produce structures close to the central star but the seed of structures observed in post-AGB stars, such as bipolar outflows or rotating disks, could be developed at the end of the AGB stage. A structure that could be the origin of a bipolar outflow or a rotating disk with a size of ~0.2" was discovered close to the photosphere of the AGB star R Leo. We propose to perform high angular, high sensitivity interferometer observations with ALMA towards R Leo to observe any structure in its envelope involving scales of the order of 1R* in order to throw some light on this matter. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2018-04-06T22:34:35.000 |
| 1105 | 2023.1.00404.S | 0 | Investigating the impact of the most powerful outflows known | We propose high-angular resolution band-6 observations of the CO(7-6) line and continuum emission in two dusty-obscured quasars at z=2.4. These quasars are currently driving the fastest, most massive ionized outflows at galactic scales known so far with velocities up to 7000 km/s. Recent low-resolution ALMA observations also reveal large-scale (~20 kpc) cold gas halos around these quasars, likely created by outflows. Observations with a spatial resolution of ~850pc will enable us to map the dense molecular gas and dust in the quasar host galaxies and test whether the fast outflows really deplete gas and dust in the nuclear region within 2 kpc from the supermassive black hole (SMBH) as expected by recent cosmological simulations of galaxy formation. The CO(7-6) observations will also be used to quantify the impact of outflows on the gas kinematics and SMBH growth. Given the remarkable outflow properties, evidence for feedback in action should be observed in these quasars. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-12-19T23:36:58.000 |
| 1106 | 2016.1.00596.S | 61 | Dissecting molecular clouds at 0.2 pc resolution in our nearest low-metallicity laboratory: where is the CO-dark gas? | Understanding star formation in metal-poor galaxies provides important insights on galaxy evolution. However, as the metallicity decreases, cold molecular gas cannot be traced easily since CO is photodissociated where H2 remains self-shielded. Therefore, the exact role of molecular gas in star-formation process and efficiency is not well known. Models show that a substantial fraction of H2 can be in the C^0-emitting region (the CO-dark gas), and [CI]/CO in particular is a robust tracer of the CO-dark gas fraction over a wide range of physical conditions. We propose a detailed modeling of the photodissociation front and molecular cloud at 0.2pc in N44 and N159 in the Large Magellanic Cloud at half-solar metallicity. These regions probe a wide range of physical conditions and CO-dark gas mass fractions, providing an ideal test for CO-dark gas determination down to 0.2pc scales. With ALMA we will map [CI]609um, 12CO(2-1), 13CO(2-1) and the dust continuum at 0.9" resolution and resolve spatially and spectrally the molecular clouds. We will identify the origin of [CI] as the molecular core layer and/or from the interclump medium and quantify the fraction of CO-dark gas at sub-pc scales. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2018-01-25T22:00:02.000 |
| 1107 | 2019.1.00909.S | 284 | ALMA spectroscopic follow-up of high-z low-luminosity AGN candidates in the CDF-S | The study of the population of low-luminosity AGN at high redshift, which is critical for our understanding of SMBH/galaxy evolution, is largely impeded by the low spectroscopic identification rate. We propose spectral scans to identify spectroscopically 7 high-redshift (z=3-4) X-ray selected low-luminosity AGN candidates with previous ALMA detections at 850um (S850um=[2.9-6.6] mJy). They are hosted by faint galaxies (F125W=23.3-27.0), for which near-IR spectroscopy is very costly (>10h integration) and has a low probability of success due to highly obscured nature. The observations will test the veracity of the photometric redshifts for low-luminosity and often obscured AGN hosted in SMGs at z>3, for which suitable SED models are lacking. With CO lines in hand, we can derive the total gas mass, and compare it with the column density derived from X-ray spectral analysis to estimate the contribution of the ISM to the high obscuration observed in high-z AGN. Thanks to the excellent ancillary data available, we will derive the gas fraction, gas depletion time, and star formation efficiency, characterizing for the first time the host galaxy properties of low-luminosity AGN at z=3-4. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-04-19T06:37:55.000 |
| 1108 | 2015.1.00902.S | 50 | Kinetic temperature measurement within galaxies | Luminous infrared galaxies, LIRGs, are characterized by high far infrared luminosities from active galactic nuclei and extreme starbursts that are very compact with the bulk of their molecular gas in a very dense phase. Recent evidence points to very elevated cosmic-ray (CR) energy densities and/or extreme turbulence rather than far-UV/optical radiation fields predominantly heating their massive dense gas reservoirs. If this is indeed the case, it will lead to fundamental consequences for all SF events with high star formation rate (SFR) densities taking place in the local or distant Universe, as it will likely alter the initial conditions of star formation and perhaps even the stellar initial mass function (IMF) in a systematic way. Formaldehyde (H2CO) is an excellent tracer of molecular gas to study gas excitation as demonstrated in Galactic studies. We therefore propose to observe the transition lines of H2CO at 218 GHz towards a sample of LIRGs at different evolutionary stages to determine their gas kinetic temperature. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2017-12-07T05:04:11.000 |
| 1109 | 2015.1.00262.S | 41 | Digging for rusty bullets at an explosion site | We propose a dig for rust among the bullets of Orion. The Orion outflow contains a spectacular collection of [Fe II]-bright shocks, indicating that gas-phase iron is abundant within the region. However, molecular gas phase iron has never been detected here and has only once been detected in space. Given that iron is among the most abundant species in the universe, it is important to understand where it is hiding and what can bring it to light. FeO is among the simplest molecules iron can form and should be one of the most abundant. We will search for it along the shock fronts of the Orion bullets, looking for signs that iron is released in a molecular form from sputtered dust grains. | Outflows, jets and ionized winds, Astrochemistry | ISM and star formation | 2017-09-05T18:07:43.000 |
| 1110 | 2022.1.00710.V | 0 | First subparsec-scale imaging of the new TeV gamma-ray radio galaxy 3C 264 | Since the first detection of astrophysical gamma-rays, numerous active galactic nuclei have been detected up to extreme TeV photon energies. While the vast majority of them, blazars, have strong jets sharply aligned to the observers and their TeV emission is well explained by the strong Doppler boosting, a new class of TeV sources, radio galaxies, raises a serious challenge to this interpretation because of their misaligned jets. 3C264 is the sixth newly discovered TeV-emitting, FR I radio galaxy with a uniquely collimated and edge-brightened pc-scale jet, similar to another TeV radio galaxy M87, but has not been imaged on subparsec scales or <1000 Schwarzschild radii (Rs). We request the first deep and high resolution imaging of 3C264 at 86 GHz with GMVA+ALMA, resolving the jet base region, a possible site of TeV production, down to 50uas (500Rs) scales. The new image will allow better understanding of the beaming, collimation, and stratification of the outflow, and pining down the magnetization of the compact core. This will sharply constrain possible TeV emission mechanisms in 3C264, and also enable a direct comparison of the physics to that in the similar TeV source M87. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-08-29T05:02:45.000 |
| 1111 | 2022.1.01686.S | 117 | Testing the primordial origin of CO in debris discs | The presence of even tenuous gas influences planetary atmospheric compositions. If gas is released from planetesimal collisions, it can enrich planets in heavy elements and favour habitability. Such a process is suspected to be ongoing in a number of debris discs around A-type stars, where CO is detected. However, recent theoretical work suggests that this gas may instead be primordial, H2-dominated. Inefficient FUV photoevaporation is argued to enable gas to survive around A-type stars, specifically. To test this hypothesis, we intend to search for gas in the youngest debris discs, pre-main sequence (PMS) progenitors of known gas-bearing debris discs, identified in a recent unbiased survey of PMS intermediate mass stars. Our targets (<10Myr) are caught in transition between protoplanetary and debris disc phase, as indicated by their mid-IR emission. We intend to probe CO gas and millimetre dust emission from this unique set of objects, in order to test and quantify primordial CO gas survival in the earlest debris disc phase. If gas is not detected, this would imply that any gas found around older, main-sequence stars (15-50~Myr) must be collisionally produced, and not primordial. | Disks around high-mass stars | Disks and planet formation | 2023-10-28T18:53:33.000 |
| 1112 | 2016.1.00315.S | 23 | ALMA Zooms in on Planet Formation in a Nearby Disk Orbiting Twin Young Suns | Planets form in circumstellar disks of gas and dust orbiting young stars. In the era of ALMA, imaging of dusty (submm-luminous) protoplanetary disks can achieve 20-30 mas angular resolution, comparable to that of visible/near-IR (scattered-light) imaging of disks using EAO instrumentation on 8-meter-class telescopes. This potential is best exploited by imaging the nearest known planet-forming disks, for which ALMA's spatial resolution approaches AU size scales. Here, we propose extended-configuration ALMA 870 continuum and CO imaging of the massive, evolved circumbinary disk orbiting the close binary system V4046 Sgr (D ~ 73 pc), one of the nearest known and most intriguing protoplanetary disks. These observations will yield an unsurpassed benchmark with which to test models describing grain growth and migration processes that are predicted to accompany planet building, and to investigate planet formation in the giant and terrestrial planet-forming regions of a binary system consisting of twin young solar analogs. | Disks around low-mass stars | Disks and planet formation | 2018-06-01T20:45:55.000 |
| 1113 | 2019.2.00053.S | 36 | First direct measurements of dust temperature in quasars at cosmic dawn | Among the >60 quasar host galaxies detected in [CII] and underlying dust continuum to date above z=6, when the universe was <1 Gyr old, only three have a published measurement of their dust emission in temperature-sensitive bands (at rest wavelengths <150 um). In order to infer key quantities in the characterization of these early massive galaxies, such as IR luminosities and associated star formation rates, we wildly extrapolate from the temperature-insensitive Rayleigh-Jeans part of the dust emission, or we need to assume templates. Here we propose to alleviate these restrictions by sampling the observed 400 GHz (~100 um rest-frame) dust continuum in quasars at z>6 using the ACA. We target all of the 13 quasars known at these redshifts that 1) have been already detected at 158um (rest-frame) with F_nu>1.5 mJy; 2) have not been observed in band 8 with ALMA or detected with Herschel; 3) are visible from ALMA. Each observation can be carried out within a few hours. As the quasars are spread over the sky, this program is an excellent filler for the ACA, and does not require the sensitivity nor the angular resolution of the main array. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2022-10-15T02:09:32.000 |
| 1114 | 2024.1.00412.S | 0 | Directly detecting cool molecular gas in z>6 star-forming galaxies | JWST's discovery of particularly massive galaxies in the Universe's first billion years has reignited long-standing questions about the rapid growth of early (z>6) galaxies. Molecular gas fuels star formation, and it is therefore key to identify and study the z>6 galaxies with the most massive molecular gas reservoirs. Here we propose ALMA Band 1 CO(3-2) observations of 3 z=6.0-6.6 star-forming galaxies serendipitously discovered via ALMA spectral line (e.g., [CII]) observations around massive QSOs. These (non-lensed) galaxies have SFRs >100 Msol/yr and [CII] luminosities >3x10^9 Lsol, hinting that they host the most massive z>6 molecular gas reservoirs (~10^11 Msol) known to-date. The requested observations will directly confirm their massive gas reservoirs with low-J (J<=3) CO observations, providing crucial insight into the ISM physics driving their rapid assembly (via, e.g., t_depletion) and testing the use of the easily detectable [CII] line as a gas mass tracer at the highest redshifts. The latter goal will have profound implications for the measurement of molecular gas masses in large z>6 samples. The QSOs in the fields will be automatically covered for free. | Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1115 | 2019.1.01010.S | 140 | Tracing Molecular Gas Across the Stages of Accretion onto a Galaxy Cluster at z=1.487 | The epoch z=1-2 is inhabited by massive clusters which are actively assembling their final populations, with star formation (SF) activity comparable to the field, just prior to the widespread quenching that defines clusters at z<1. This transitional phase provides a crucial link between passively-evolving clusters at low redshift and the emerging proto-cluster studies at z>2. We propose Band-3 observations to obtain the CO(2-1) emission line in a complete survey of infrared-bright star-forming galaxies (SFGs) within the virial radius of a massive galaxy cluster at $z=1.487$. Using multi-wavelength data including deep Herschel/PACS imaging, we have characterized SF and AGN in the dusty cluster galaxies which dominate the final stages of significant mass assembly. A necessary next step is to quantify the current gas reservoirs (via gas fractions and SF efficiencies) and accretion histories (via phase space diagrams) of these active members through CO emission, providing key constraints on environmental drivers of galaxy evolution. | Starbursts, star formation, Galaxy groups and clusters | Active galaxies | 2024-02-01T22:38:27.000 |
| 1116 | 2017.1.01353.S | 148 | Fragmentation in the Orion Integral Shaped Filament | The majority of young stars form within embedded star clusters and they are almost always associated with filamentary molecular clouds. These filaments can extend over parsec size scales and often show hierarchical structures. This indicates that multi-scale fragmentation processes within the filaments play a central role for the star formation process. In this proposal, we request time to perform the first extensive ALMA survey of the Orion A Integral Shaped Filament that is optimised to detect the fragmentation structures through dust continuum observations. Our observations will extend the mass sensitivity by an order of magnitude better than existing observations at the ISF. This enables us to probe the fragmentation process in the brown-dwarf mass regime, to determine any limits to the fragmentation structure, and to determine if the preferred fragmentation scale varies with mass and density. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-02-06T00:00:00.000 |
| 1117 | 2022.1.01772.S | 76 | Resolving the duality of star-formation relations in LIRGs | We propose to map the emission of a set of dense molecular gas tracers (HCN(1-0), HCO+(1-0) and CS(2-1)) in six local LIRGs using the unique spatial resolution (0.2"~65 pc) and sensitivity of ALMA. This project builds on improving our knowledge of the formation and evolution of galaxies from the study of the star formation relations. The use of specific molecular gas tracers can probe the influence of the dynamical environment in the star formation process. Just recently, several works found that the star formation occurs in certain regions within galaxies, more specifically, some local LIRGs show a dual behaviour in the star formation relations. This duality shows two different dynamical environments depending on the distance relative to the centre of the galaxy. This project focuses on characterising the mechanisms involved in the dual and non-dual behaviour of local LIRGs found in the star formation relations and gives us information about the influence of the dynamical environment at forming stars. This work also helps to improve the star fomation models. | Starbursts, star formation | Active galaxies | 2024-06-06T16:47:35.000 |
| 1118 | 2017.1.00043.S | 21 | Detailed Physical Properties of the Interstellar Medium in a z=5.2 Dusty Starburst (Completion) | Studies of the interstellar medium (ISM) at high redshift have progressed tremendously in the past years, but studies of the physical properties based on a suite of fine structure lines (which are critical for studying the earliest cosmic epochs, where CO is faint due to decreasing metallicity) are still in their beginning stages. We here propose to complete our in-depth study of the ISM based on six CNO fine structure lines in a massive starburst galaxy at redshift 5.2 (where all lines fall into a "sweet spot" in the atmosphere), allowing us to push these studies back to the first billion years of cosmic time. This will allow us to measure the fraction of [CII] emission that originates from the neutral vs. ionized medium, the density of both the neutral and ionized medium, the effective temperature in HII regions associated with star-forming clouds, and the O/N abundance ratio. This study will detect fine structure lines up to rest-frame wavelengths of 52 micron in one of the most distant starburst galaxies known, making it an ideal demonstration case for the ALMA band-10 receivers. (Program fully scheduled at high priority in cycle-3, but not completed due to weather.) | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-10-23T17:41:44.000 |
| 1119 | 2017.1.01194.S | 0 | Investigating the evolution of the dwarf disk in XZ Tau B in real time | Using ALMA LBC SV data we imaged, on the edge of the field-of-view, a dwarf transitional disk around the young star XZ Tau B (Osorio et al. 2016). The disk has an outer radius of only 3.4 au and a central cavity of radius 1.3 au. Because of its small size, orbital periods are short and rapid changes are expected in the disk azimuthal structure that could be observable on timescales of just a few months. We requested Cycle 4 observing time to obtain a first-epoch high-quality image of the disk centered on the source. These Cycle 4 observations are scheduled in June 2017. Here we are requesting a second-epoch image in Cycle 5, to be observed in October-November 2017. The two images will be obtained with a difference of 4-5 months, allowing to observe changes in the azimuthal structure of the disk during this time interval. Extrapolation of these results, together with additional monitoring, will provide a robust basis for characterizing the slower evolution of larger disks. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2018-12-15T08:43:02.000 |
| 1120 | 2021.1.01626.S | 28 | CLoGS ACA | The dominant ellipticals of cool-core galaxy clusters host filamentary nebulae of ionized and molecular gas, thought to form through cooling from the hot intracluster medium. This gas plays a critical role as fuel in the AGN feedback cycle. In the general population of ellipticals, only ~20% contain molecular gas, often in disturbed rings/disks indicative of acquisition through gas-rich mergers. Galaxy groups occupy the interesting intermediate mass range, and are a favorable environment for both cooling flows and gas-rich galaxy mergers. A survey of 53 group-dominant galaxies shows that ~40% host molecular gas, but its origin is as yet unclear. We now propose to observe four CO-rich group-dominant galaxies with ACA with the aim of determining the origin of the gas via its morphology and kinematics. The observations will determine whether the gas is in rings/disks, tidal structures, or cooling filaments. Comparison with multi-frequency radio data, UV/optical imaging, and in two cases MUSE data, will allow us to examine any correlation with star formation and determine the mass of molecular gas in the central kiloparsec, available for AGN fuelling. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2023-12-27T22:16:05.000 |
| 1121 | 2015.1.00324.S | 20 | A gigamaser at z=0.66 | We propose to observe the fundamental lines of water at 183 GHz and 380 GHz in a type 2 quasar at z = 0.66. Extremely luminous water maser emission at 22 GHz has been previously detected in this intermediate redshift target, pointing to large reservoirs of water around its active nucleus. Detection of these sub-millimeter lines would provide a new tracer of energetic phenomena and would help constrain the physical paramters and excitation conditions in an active environment. All previous attempts to observe water at 183 GHz and 380 GHz from ground-base telescopes have been extremely challenging due to the high water opacity at those frequencies in our atmosphere. The best place to currently search for them is in high redshift galaxies. Only with ALMA can these lines be observed with enough sensitivity. Moreover, before Band 5 becomes available, this is the only source with a powerful megamaser detection that can currently be observed. The target is also part of a radio-loud, extremely luminous MIR sample; if detected in the sub-millimeter, this sample might become an excellent place to search for new megamasers, making this an important pilot. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy chemistry | Active galaxies | 2017-08-26T01:28:42.000 |
| 1122 | 2017.1.00113.S | 27 | Imaging Vibrationally-Excited Molecules in Galaxy Nuclei | We propose very high-resolution (4-11 pc) imaging of lines from vibrationally excited molecules (vib-lines) toward three prototypes of the Compact Obscured Nuclei (CON) of galaxies. A CON hides behind an enormous column of obscuring dust either a heavily Compton-thick AGN of high Eddington ratio or an extreme young, compact starburst, or both. Being radiatively excited by IR photons from hot dust, the vib-lines selectively trace the hot centers of CONs that are hardly visible in usual mm/submm lines because of (self)absorption. We aim to uncover in our targets 1) the distribution of luminosity-tracing vib-lines, 2) gas kinematics in the centers of the CONs, 3) the shapes and sizes of the continuum cores at <10 pc scale. We will then 4) constrain the nature of the CON luminosity sources using the L/M parameter measured with our observations. We use a vib-line that is strongest known, and observe galaxies that are the strongest emitters of the vib-line. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2020-10-01T17:32:51.000 |
| 1123 | 2013.1.00437.S | 60 | Establishing the Disk Mass-Stellar Mass Scaling Relation | The disk mass is among the most important input parameters of every planet formation model determining the number and masses of planets that can form. Indeed, the occurrence rate of exoplanets shows trends that are likely the result of stellar mass dependent disk masses. However, the biased population of known exoplanets cannot discriminate between different scaling relations between disk mass and stellar mass. Here we propose a sensitive ALMA survey to measure dust masses for all Chamaeleon I disks around objects from ~2 to 0.05 solar masses (SpTy: G2-M7). This unique coeval sample of 93 disks will: 1) establish how the disk mass scales with the mass of the central star and 2) constrain average disk masses and their spread over a range of 40 in stellar mass. As a bonus our settings cover lines from two CO isotopologues that can be used to trace gas in these disks. Our survey fully samples the numerous but faint M dwarfs which are attractive targets to search for Earth analogues in the habitable zone. In combination with ancillary data our group is assembling we will also test disk dispersal theories and provide an ALMA legacy for followup studies of disks around young stars. | Disks around low-mass stars | Disks and planet formation | 2016-07-01T03:03:05.000 |
| 1124 | 2023.1.01082.S | 0 | Where and how do low-mass stars form in massive hub-filament systems? | Hub-filament systems (HFS), a specific morphological category of clumps, are networks of converging interstellar filaments where active star formation happens. Massive HFS produce high-mass stars at their centers and then form massive proto-clusters. Existing ALMA observations toward 35 massive clumps predict high-mass stars form at earlier stages, but more low-/mid-mass stars as HFS evolves. However, where and how these low-mass stars form in high-mass HFS is still unclear but essential to constraining how massive clusters form. To shed light on this question, a panorama of HFS with high spatial resolution and flux sensitivity is necessary. Therefore, we propose a 102-pointing large mosaicked observation of prototypical HFS SDC335 at ALMA Band 6. With the data, we expect to find out where low-mass stars are preferentially located in HFS and how they form along with the evolution of clusters. The proposed ALMA observation will be part of a Ph.D. thesis. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-07-02T10:38:47.000 |
| 1125 | 2018.1.00802.S | 4 | Probing the chromosphere of coronal holes and coronal hole boundaries | The Sun's magnetic field displays two main topologies. Most common are regions with closed magnetic fields (quiet Sun, QS), while the regions of open magnetic flux (coronal holes, CHs), although usually covering less area, are of equal importance as the source regions of the fast solar wind. The coronal hole boundaries (CHBs), where intensive interchange reconnection takes place, are sources of the slow solar wind. We propose to observe mid-latitude coronal holes and their boundaries in ALMA bands 3 and 6 to study the dependence of chromospheric structure and heating on the magnetic field's topology and to search for signs of enhanced heating produced by magnetic reconnection at CHBs. In the corona CHs and QS display large differences. In the chromosphere similar differences are expected if the heating is magnetic and are predicted by state-of-the-art simulations. The evidence from optical spectral lines is mixed as they often decouple from the ambient temperature, and only ALMA diagnostics, whose formation is well understood, can distinguish clearly between heating mechanisms of the chromosphere. Additionally, ALMA data will test the simulations and help identify missing physics. | The Sun | Sun | 2022-03-24T05:04:06.000 |
| 1126 | 2018.1.00232.S | 89 | Galactic Chemical Structure in the Southern Sky: A Pilot Project | Azimuthal metallicity fluctuations have been found in the Galactic disk from radio recombination line (RRL) and continuum data. These fluctuations are inconsistent with expectations that the disk is well-mixed due to differential rotation. This may indicate that radial gas motions from the bar are a significant factor for chemical evolution. CNO isotopic ratios are a nice complement to metallicities since they measure the degree of primary to secondary processing. CNO ratios can confirm this azimuthal structure and better constrain Galactic chemical evolution models. We propose to use the ALMA Compact Array (ACA) to measure the 12C/13C, 14N/15N, and 16O/18O isotopic ratios toward a sample of HII regions in the Southern sky to explore the radial and azimuthal chemical structure in the Milky Way disk. We plan to observe the following molecular tracers: CN(N=1-0), 13CN(N=1-0), C15N(N=1-0), 13CO(J=1-0), and C18O(J=1-0). Our tuning configuration will also include the continuum to measure the thermal emission as well as the H38alpha RRL. Here we propose a pilot project to observe CN emission in 11 sources to assess the feasibility of this project. | HII regions | ISM and star formation | 2020-01-25T22:39:17.000 |
| 1127 | 2016.1.00063.S | 147 | Zooming in on the parsec-scale structure of CO gas at low metallicity and its relation to star formation | The star formation rate is proportional to the surface density of molecular gas, for a wide range of metallicities. Models predict that the structure of CO-emitting gas should change with metallicity and radiation field: extended CO emission and CO "clumps" should shrink as metallicity decreases or radiation field strength increases. This effect has never been directly observed before, and models of CO formation have not been put to a test. Additionally, the effects of those changes on the star formation process, which occurs in dense, CO-emitting gas, are unknown. We propose to obtain deep maps of two transitions (1-0 and 2-1) of three CO isotopes (12CO, 13CO, and C18O) in 6 regions of two low-metallicity galaxies, the LMC and the SMC. These observations will allow us to test CO photo-chemical models by providing deep maps of the pc-scale structure, column density, thermal, and chemical state of the CO-emitting gas at two low metallicities and a range of radiation fields. By comparing the CO maps to pc-resolution tracers of star formation, specifically 24 micron emission and young stellar objects, we will bridge the gap between Galactic and extragalactic star formation studies | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-06-04T00:00:00.000 |
| 1128 | 2016.1.00846.S | 66 | Testing MHD jet launch models with ALMA: Jet and disk rotation in CTTSs | A fundamental open question in Star Formation is how a newly forming system looses angular momentum from the disk to allow mass accretion to proceed. MHD models suggest that the excess angular momentum can be transported away with the ejection of large scale bipolar jets. Observational tests of these models, however, are difficult due to the small spatial scales of the accretion-ejection zones within the disk-jet system. If jets are launched by a magneto-centrifugal mechanism it is expected that they rotate in the same sense as the disk and at a given rotation rate. Therefore, a direct way to test the models is to measure both the disk and jet rotation. This has to be done close to the launch region in order to avoid environmental contamination of the jet kinematics. To this aim, we propose to observe DG Tau and DG Tau B at 0.15" angular resolution and 0.16 km/s spectral resolution by using high-velocity CO 2-1 to probe the molecular jet, and a high-density tracer, CN 2-1, to trace the disk. This will allow us to obtain for the first time accurate rotation curves of the disk and the jet and to conduct a conclusive test of the proposed MHD models. | Outflows, jets and ionized winds | ISM and star formation | 2018-10-20T19:15:18.000 |
| 1129 | 2013.1.01065.S | 5 | Star Formation in a Highly Turbulent Massive Clump in the Galactic Center | It is widely believed that turbulence effects on the star formation in the central molecular zone, both forbidding and accelerating star formation. In particular, cloud-cloud collision initiated by the bar-driven inflow of molecular clouds or by feedback from past active star formation may be efficient formation process of stellar clusters cluster. Recently we detected a peculiar molecular clump not associated with major star forming GMC complexes. The clump CO-0.30-0.7 has a extremely large velocity width of 120 km/s, indicating that the entire clump is disturbed by shock possibly caused by interaction with an adjacent large expanding shell. Interestingly, the clump also has a compact core of 300-500 solar masses with narrow line width (20 km/s), which is virialized and hence capable of forming stars. At present no sign of star formation is detected toward the clump, and we speculate this is a region where cloud-cloud collision has just started, which may possibly lead cluster formation, or destruction of cloud cores. We propose imaging of this clump to resolve small-scale structures of this clump and investigate how turbulence effects on the physical properties of them. | High-mass star formation | ISM and star formation | 2016-07-21T06:20:00.000 |
| 1130 | 2018.1.00385.S | 11 | In transition: search for the accretion disk inside the hypercompact HII region G345.49+1.47 | This proposal aims to detect for the first time a disk/jet system inside of a hyper-compact (HC) HII region: G345.49+1.47. This yet unobserved stage is expected to exist in the evolution of forming massive stars, if disk accretion characterizes their growth after the onset of ionizing radiation. G345.49+1.47 is an excellent candidate to reveal such a system. Using ALMA long baseline observations --- with angular resolution of 0.03" correspondig to 50 AU physical resolution --- we propose to resolve the HC HII region associated with its exciting young massive star and to search for the disk/jet system. Dust continuum and molecular line tracers aiming to a range of possible optical depths (13CO, C18O, and C17O) plus high-excitation SO2 lines are the tracers that maximize the plausibility of detecting this stage. | Disks around high-mass stars | Disks and planet formation | 2021-04-09T00:00:00.000 |
| 1131 | 2022.1.01644.S | 13 | Molecular gas distribution and dynamics in main-sequence galaxies at the peak epoch of the cosmic star formation | Sensitive measurements of the CO emission line in high-z galaxies at sub-galactic scales are now possible with ALMA. We propose to build a comprehensive sample of z~2.2 star-forming main-sequence galaxies observed in CO(3-2) emission. Making use of the ALMA archive and literature, we have gathered bright unresolved CO(3-2) detections for five galaxies to perform follow-up observations and resolve the galactic disks at 3-5 kpc-scale. We will characterize the gas distribution and dynamics of the likely dominant component in term of mass in those main-sequence galaxies. We will measure and compare the molecular gas extension and rotation velocities with the average values previously measured from the large Halpha IFU surveys. Hence, we will provide clues about how galaxies build-up their stellar mas content at the ``cosmic noon''. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2024-10-25T14:11:29.000 |
| 1132 | 2016.1.00956.S | 85 | The 14N/15N isotopic ratio in the comet forming region of protoplanetary disks | We propose to spatially resolve the radial dependence of the 14N/15N ratio within the planet and comet forming region in the protoplanetary disk around V4046 Sgr. Isotopic ratios are commonly used to trace the origin of Solar System bodies. This is a fundamental but still highly debated topic. It is still unclear whether most of the organics are inherited from the protosolar nebula or if they are the result of an active chemistry in the protoplanetary disk phase. Disk-averaged 15N enrichments that are similar to comets have been observed in disks. However, spatially resolved observations of N isotopic ratios are needed to elucidate the origin of these 15N enrichments, and ultimately the origins of organics, across the Solar System: a constant 14N/15N ratio across disks would favor a scenario where disks inherit their organics from the natal cloud, while a gradient would strongly suggest that the chemistry is modified during the disk phase. | Disks around low-mass stars | Disks and planet formation | 2018-05-24T17:12:58.000 |
| 1133 | 2015.1.00808.S | 9 | A jet-driven cold gas outflow in the radio galaxy PKS1740-517 | Using the first six antennas of the Australian Square Kilometre Array Pathfinder (ASKAP), we have discovered strong redshifted 21cm absorption associated with cold, dense HI gas surrounding the young radio galaxy PKS1740-517 at redshift z=0.44. The line profiles seen in the 21cm and optical spectra of this galaxy imply that the radio AGN is driving a fast outflow of neutral and ionised gas, but our information on the neutral gas kinematics is currently limited to the single narrow sightline on which HI absorption is seen. Detecting and imaging the molecular gas in PKS1740-517 with ALMA will allow us to study the global distribution and kinematics of the cold neutral gas in a distant active galaxy that is undergoing the earliest phase of radio AGN feedback. At the position and redshift of this galaxy, ALMA is the only telescope in the world which can detect and image the neutral molecular gas. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-08-25T20:35:34.000 |
| 1134 | 2021.1.01496.S | 78 | Trace the molecular gas reservoir in ULIRGs with co-existing extreme ionized outflows and vigorous starbursts | Ultra-luminous IR galaxies (ULIRGs) are thought to represent the rapidly growing phase of massive galaxies before quenching of star formation (SF) by powerful AGN-driven outflows. In a recent follow-up of ULIRGs at z ~ 0.5 with AKARI FIR catalog, five ULIRGs are found with extremely fast outflows (v > 1500 km/s), which are the most powerful outflows observed in ULIRGs/AGNs at z<1. However, the SF activities in the five ULIRGs are highly intense with SFR of 300-2000 Msun/yr. The co-existence of extremely strong outflows and starbursts is conflicting with the classical AGN feedback scenario. One possibility is that although the AGN wind is powerful, it has only affected the hot, ionized gas, but not affected the cold, molecular clouds in which SF occurs. In order to reveal the physical explanation behind the co-existence of strong outflows and SF activities in these ULIRGs, it is crucial to trace molecular outflows with spatially resolved observations using ALMA. The targets are unique to examine the puzzling co-existence in details, e.g., high physical resolution and low excitation CO line coverage, compared to more distant high-z ULIRGs with similar outflows and SF activities. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-06-07T02:46:07.000 |
| 1135 | 2023.1.00228.S | 0 | Resolved CI study of different star forming environment | CI has been favored as an alternative molecular gas tracer due to its simple 3-level fine structure lines. A tight linear relation has been found between global CI and CO 1-0 luminosity, suggesting CI works well as a global gas tracer. However, only a handful of studies have focused on CI variations within galaxies. A recent study of the LIRG IRAS F18293-3413 shows a superlinear relation between CI and CO 1-0 luminosity at 300 pc scale, which can be due to various enviromental factors. To further study this relation, we propose to observe CI 2-1 along with Band 10 continuum at ~200 pc scale for two nearby galaxies (NGC 3267, NGC 660) and two LIRGs (NGC 5104 and IRAS F18293-3413), which already have archival CI 1-0 observations. We also propose for complementary CO 1-0 observations for the galaxies that do not have suitable archival CO data. From these observations, we will fully constrain the gas properties and separate out the influence of different enviromental factors on the CI-CO correlation. | Galaxy chemistry, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2025-03-12T11:45:25.000 |
| 1136 | 2024.1.01129.S | 0 | Statistical Study of Cores at the Onset of High-mass Star Formation | This proposal aims to conduct mosaic observations in Band 6 to statistically study the spatial distribution and population of cores toward forty 70 µm-bright clumps not associated with HII regions. Recent works suggest that cores found in massive 70 um-dark clumps will grow in mass to eventually form high-mass stars. Those cores that grow the most are the ones near the center of the clump's gravitational potential, naturally making a mass-segregated cluster. By comparing core properties in evolved 70 µm-bright clumps with those in early-stage 70 µm-dark clumps, we aim to address the following key questions: (1) does mass segregation or the preferred location of high-mass cores appear later on in evolution? (2) how do the properties of the cores in 70 µm-bright clumps compare with those in 70 µm-dark clumps? To address these questions, we study the core properties, such as mass, protostellar/prestellar ratio, and the preferred location of higher-mass cores. The proposed observations will provide valuable insights into the early stages of high-mass star formation, and contribute to the development of more accurate theoretical models. | High-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1137 | 2013.1.00293.S | 2 | Detecting atmospheric ionisation from ultracool dwarfs with ALMA | We will observe the ultracool dwarf TLVLM513-46546 using band 3 of ALMA to detect radio emission from plasma in the upper atmosphere. This plasma may have been caused by a variety of mechanisms such as cosmic ray impacts, charged particles causing lighning strikes, or Alven emission. Alfven emission appears the most likely cause of the plasma as it requires a localised magnetic field (which is ~1 kG in TVLM) and particle movement caused by rotation (TVLM has a fast rotation period of 2 hours). This radio emission will be the first to be detected that cannot be attributed to the electron cyclotron maser instability, and using the magnetic field strength, we will calculate the electron number density in the atmosphere, the first time this will have been achieved for an ultracool dwarf. This is particularly important as it will allow much more accurate modelling of plasmas in ultracool dwarf and exoplanet atmospheres, particularly where irradiation and cloud formation are concerned. | Brown dwarfs | Stars and stellar evolution | 2016-04-21T18:17:44.000 |
| 1138 | 2024.1.00422.S | 0 | The Shape of Water: explore the origin of water emission in extragalactic environments | Submm H2O lines uniquely diagnose the ISM by connecting IR radiation fields with the warm dense ISM. Surveys of extragalactic H2O across cosmic time find a tight correlation between the H2O and IR emission, consistent with far-IR pumping, while this correlation also extends to small scales of Galactic star-forming regions where shocks tend to dominate. Thus, the origin of extragalactic H2O emission (far-IR pumping vs. shock) remains unclear because there is no spatially resolved study to distinguish the excitation regimes. We propose a first ground-based mapping of the 752 GHz H2O line in two local galaxies with ALMA (proven feasible by a previous APEX study). This first high spectral- and spatial-resolution study of extragalactic H2O will help us understand the spatial distribution and kinematics of extragalactic H2O emission. Together with the CO(6-5),SiO(4-3) and dust continuum at ~430um maps, we will be able to explore the origin of H2O emission: collisions/shocks/far-IR pumping, to better constrain the properties of the ISM and star formation. This observation will establish a benchmark for local and high-redshift extragalactic H2O studies. | Starbursts, star formation | Active galaxies | 2025-10-23T20:05:30.000 |
| 1139 | 2019.1.01156.S | 33 | Testing Core Formation Models with ALMA and BLAST Polarimetry | Tests of core formation require detailed measurements of the both the local and global molecular cloud magnetic field, as well as detailed observations of magnetic fields within a large sample of cores. In this proposal, we request time to map polarized dust emission in the envelopes of all identified Class 0 and I protostars in the extremely young giant molecular cloud Vela C. Recent observations of Vela C with the BLASTPol balloon-borne polarimeter indicate that this cloud is highly magnetized on large scales. Our proposed ALMA observations will trace magnetic field structure on scales ranging from 900 AU to 5000 AU. The ALMA observations will be compared with BLAST maps of large and intermediate scale cloud magnetic fields to create a dataset that will trace fields over four orders of magnitude in spatial scale. These observations will be compared with numerical simulations of magnetized core formation to distinguish whether cores appear to form via turbulent compression of the gas, or more quiescently through mass accretion along field lines. Our observations will provide the first quantitative tests of core formation within a highly magnetized cloud. | Intermediate-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-08-17T21:27:07.000 |
| 1140 | 2022.1.00599.S | 92 | Large dust particles in the peculiar comet C/2017 K2 | The Oort cloud comet C/2017 K2 (hereafter K2) is remarkable for developing a coma at a record heliocentric distance of 35 au. The detection of K2 beyond the orbit of Uranus offers an unprecedented opportunity for us to examine the evolution of a pristine comet arriving into the inner Solar system from near-interstellar temperatures. The well-preserved dust and ice in this pristine comet holds valuable information about the physical processes during the formation of the Solar system. Our goal is to map the thermal emissions from large dust particles over four ALMA bands, 3, 4, 6 and 7 to yield strong constraints on the physical properties of millimeter-sized grains, which dominate the coma mass of K2, via dust modeling. The superb sensitivity of ALMA provides the only way to study the large particles of this comet. Taking advantage of ALMA's unique capability of observing dust and gas simultaneously, we will also observe CO and HCN emission lines of K2 in 3 ALMA bands and derive the dust-to-gas ratio of this comet. This study will shed light on our understanding of comet formation in our Solar system and possible disk processes for planet formation around other stars. | Solar system - Comets | Solar system | 2024-03-31T08:59:28.000 |
| 1141 | 2023.1.01674.S | 6 | Probing the host galaxy of the highest-redshift OH megamaser | In the local universe, powerful OH megamasers (OHMs) are found in the centers of gas-rich major mergers, with a prevalance that increases with far-IR luminosity. Their brightness means that OHMs are predicted to be significant contaminants of deep HI surveys with new radio facilities, and potentially useful as tracers of the cosmic history of gas-rich mergers. As a first step in this direction, South Africa's MeerKAT array has recently detected a z = 0.52 OHM (dubbed "Nkalakatha"), which is not only the first OHM seen in emission at z > 0.27 but is also one of the most luminous known OHMs at any redshift. We propose to observe multiple molecular lines in Nkalakatha's host galaxy, in order to characterize its gas properties and test assumptions on which efforts to connect OHMs to the cosmic merger history will depend. The requested data will determine whether Nkalakatha is hosted by a recent or ongoing merger, whether it is powered by star formation or an AGN, and what the properties of its tentatively detected molecular outflow are-- all questions with potentially broad implications. | Starburst galaxies | Active galaxies | 2024-11-06T17:45:59.000 |
| 1142 | 2015.1.00802.S | 0 | Pinpointing dust-enshrouded star-forming regions within young proto-cluster galaxies at z=2.16 | We propose ALMA Band-7 (870um) observations of H-alpha-selected, massive star-forming galaxies (with ULIRG-class IR luminosity) selected in a rich proto-cluster environment at z=2.16 (PKS1138-262). By spatially resolving their dust continuum emission on ~1-kpc scale, we will identify dust-enshrouded star-forming clumps inside the galaxies, and pinpoint the location of most intense dusty starbursts (hence rapid stellar build-up) within the young cluster galaxies. By comparing the nature/luminosities of SF clumps within proto-cluster galaxies with those of general field galaxies at the same redshift (which will be obtained through our successful ALMA Cycle-1+2 programme), we will determine if the SF clumps within the cluster galaxies tend to have boosted activity (due to their accelerated bulge growth), or if the massive star-forming galaxies reported in the proto-cluster environment are simple ``scaled-up versions'' of general field galaxies. | Galaxy Clusters | Cosmology | 2018-06-27T13:57:52.000 |
| 1143 | 2016.1.01068.S | 13 | The first face-on view of a high mass accretion system down to 50 AU | We propose the highest resolution (~0".03) imaging of dust continuum emission, towards the nearly face-on accretion system around a high mass young stellar object G353.273+0.641. The main goal is to obtain the first bird's-eye view of the innermost accretion system down to 50 AU. We investigate a surface density contrast based on 2D distribution of brightness temperature and spectral index, searching for a non-axisymmetric accretion stream that was suggested in past studies. This will be the first example of non-Keplerian dynamics in the high mass accretion system at 100 AU radius, apart from a simple picture of a homogeneous rotating or infalling disk. | High-mass star formation | ISM and star formation | 2018-10-31T18:40:30.000 |
| 1144 | 2016.1.00406.S | 45 | Sub-kpc molecular gas distribution and kinematics in a z~2 massive main sequence galaxy | We propose CO (3-2) high spatial resolution (0.3 arcsec, 500 pc) observations of the unique lensed massive main sequence galaxy SDSS J0901+1814 (z=2.26), for which matching resolution data are in hand on stellar population, star formation, and ionized gas outflows, as well as other ancillary data. The relatively undistorted sixfold amplification of the southern arc makes this the key target to study at sub-kpc resolution a massive turbulent z~2 disk with an AGN-driven outflow. Such systems are common in large statistical studies of z~2 galaxy evolution, and must be approaching the ultimate quenching of star formation. At unprecedented resolution, we will (1) determine the distribution and kinematics of molecular gas down to and below the kpc 'clump' scale, and study the gas-SFR relation, (2) search for the molecular counterpart to the nuclear ionized outflow of J0901, to determine the contribution of this phase to the outflow mass, and (3) measure gas excitation variations across a massive high-z disk. | Galaxy structure & evolution | Galaxy evolution | 2018-03-01T18:07:09.000 |
| 1145 | 2024.1.01231.S | 0 | Revealing Protocluster Growth Around Powerful Radio Galaxies Across Cosmic Noon | High redshift radio galaxies (HzRGs) are thought to pinpoint the cores of galaxy protoclusters. Yet, to date, there remains significant confusion about the Mpc-scale overdensities of obscured star formation around HzRGs. To remedy this situation, we reduced SCUBA-2 850micron data of 30 HzRGs at z=1-4.5, finding the central 6Mpc regions to be >5x overdense in submillimeter sources (SMGs) compared to the field. This depends critically, however, on spectroscopic confirmation and whether bright SMGs break into fainter sources at higher angular resolution. We propose ALMA Band-5/-6/-7 observations (FWHM~1-2") targeting CO(7-6) and [CI](2-1), and the continuum, in the 10 brightest SMGs in 10 HzRG fields (100 SMGs in total) across the Cosmic Noon (z=1.5-3.5). This will resolve the critical issues of redshift and source multiplicity, required to accurately quantify the SMG overdensities around HzRGs. It will provide unambiguous identifications in existing OIR data, allowing us to infer key physical properties of the SMGs. The outcome will be the first systematic study of SMG-overdensities and their evolution with redshift, and the physical properties of SMGs in overdense regions. | Sub-mm Galaxies (SMG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1146 | 2019.1.01240.S | 729 | Using absorption to constrain the 3D structure of the Galactic center ISM | Our current knowledge of the three-dimensional structure of gas in the center of our Galaxy is significantly incomplete. Uncertainties in the distribution of Galactic center gas are a fundamental limitation to understanding the mass flows responsible for transporting gas from hundreds of parsecs to the scale of the black hole. We propose to make observations of CO absorption toward two dozen HII regions that will directly constrain the distribution of the dense and diffuse CMZ gas in the line of sight direction. These data will break the near/far distance degeneracy for orbital models of the dense CMZ gas and resolve long-standing disagreements about the gas within 20 pc of the central black hole. Quadrupling the number of absorption lines of sight for studying the diffuse molecular gas will also significantly improve our understanding of the extent and geometry of the poorly studied low-density molecular gas, which may be the dominant mass component in this region. The positional information from this study will significantly improve our understanding of gas dynamics in the Galactic center, informing evolutionary models and facilitating comparison with other galaxy nuclei. | Galactic centres/nuclei | Active galaxies | 2021-04-29T02:30:36.000 |
| 1147 | 2012.1.00869.S | 0 | Star-formation rates for a complete sample of AGN host galaxies | Models of galaxy formation predict that nuclear activity (i.e., AGNs) has played a key role in regulating the star-formation in massive galaxies. However, conclusive evidence of this has yet to emerge from observations, with recent results from far-infrared (FIR) and sub-mm campaigns finding both enhanced and depressed star-formation rates (SFRs) in the host galaxies of powerful AGN. Such conflicting results are heavily based on stacking non-detections which currently account for the majority of AGNs in even the deepest FIR/sub-mm observations. To remove the inherent uncertainties associated with stacking analysese requires far more numbers of individually detected AGNs at FIR/sub-mm wavelengths. The ALMA observations proposed here will be sensitive to SFRs 3-7 times lower than that achieved by Herschel for a complete (at M* 5 × 10^10 M⊙ and z > 1.5) sample of X-ray detected AGNs, reaching the divide between star-forming and quiescent (in terms of star-formarion) for each. These observations will allow us to measure SFRs for a complete sample of star-forming AGN hosts and to quantify the number of quiescent hosts as a function of AGN power and redshift. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2015-04-08T16:56:18.000 |
| 1148 | 2021.1.00913.S | 42 | Are Hot Dust Obscured Galaxies at the Center of Multiple Mergers? | Hot Dust Obscured Galaxies, or Hot DOGs, are a population of high redshift, hyperluminous galaxies identified by the WISE mission, whose luminosities are powered by luminous dust-enshrouded quasars. Recent band 6 observations of the most luminous Hot DOG, W2246-0526, centered on the [NII]205um emission line, have shown that this object is at the center of a multiple merger, accreting its three closest neighbors. The deep continuum map shows dusty tidal tails that extend by up to 30kpc from W2246-0526 to the three neighboring galaxies. We request similar observations for 5 additional Hot DOGs to probe the relation between multiple merger activity and this population of hyperluminous dusty quasars. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2022-12-02T23:52:18.000 |
| 1149 | 2019.1.01012.S | 18 | Searching for Overdensities around z~5 Quasars in [CII] and Dust Continuum | Hierarchical structure formation predicts the highest-redshift quasars to exist in regions of massive overdensities as the earliest progenitors to galaxy clusters. We propose to observe 20 quasars spanning a redshift range of 55 QSOs with dust+[CII] observations by 60%, which will reduce the uncertainty in the current values of the overdensity factor delta_gal for both tracers by about 30%. We will (1) map continuum-subtracted quasar fields and perform a search for line detections around the quasar, and (2) search for evidence of an enhanced environment by comparing continuum detections with the submillimeter number counts in the literature and Lya searches for overdensities. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-07-06T15:07:31.000 |
| 1150 | 2018.1.00932.S | 105 | Extremely UV-luminous star-forming galaxies: unveiling the very early phase of SMGs | Wide and deep extragalactic surveys have been used to detect and study high-redshift normal star-forming galaxies. However, even the widest dedicated surveys have failed to discover extremely luminous galaxies, because of their very low number density. Recently, by employing novel techniques on the largest volume survey of the Universe to date, we have discovered a unique population of extremely UV-luminous galaxies that are not powered by nuclear activity, but by massive star formation. We request pilot ALMA observations to search for dust and molecular gas in five of the most luminous galaxies in our sample. These galaxies might represent a very early phase (< 10 Myr) of (sub)millimeter selected galaxies, caught when they are less attenuated by dust. They are thus ideal targets to study the early phase of massive star formation and dust mass growth of starburst galaxies at high-z. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-12-19T13:38:47.000 |
| 1151 | 2019.1.01187.S | 10 | The Mouse Pulsar Wind Nebula | The Mouse pulsar wind nebula (PWN) is archetypal bow shock PWN and is the brightest object of this type in X-rays. By analyzing Chandra data together with data taken at lower energies, we have found solid evidence that suggests the Mouse PWN is reasonably bright at millimeter wavelengths. Currently, the Crab is the only PWN observed at all frequencies between radio and X-rays, and hence, most models of PWNe (especially at lower energies) are based off this one object. The Mouse PWN will be the second PWN after the Crab where such mm-wavelength emission can be detected, and the first bow shock PWN. We will be able to constrain the electron spectral energy distribution (SED) and pulsar wind parameters (e.g., particle injection spectrum, flow speeds, magnetic field strengths) as a function of distance from the pulsar, providing a critical test for analytical and numerical models of bow shock PWNe, and allowing us to better-understand the behavior of PWNe SEDs at lower energies. | Pulsars and neutron stars | Stars and stellar evolution | 2021-04-02T14:10:29.000 |
| 1152 | 2019.2.00044.S | 69 | ACA Mapping of the Largest Supergiant HII Region in the Nearby Universe: 30 Doradus | The 30 Doradus region is the most extreme example of a supermassive HII region in the nearby universe, powered by its central R136 super star cluster. Surrounded by a complex of molecular clouds experiencing the disrupting effects of photoionization, winds, and compression by hot gas, only a small region in the very central core has been imaged/approved for imaging with ALMA. We propose to map a 15'x15' area encompassing all massive star formation in the area and most of the dusty environments, using the ACA with a high-enough sensitivity to produce high quality 13CO information. This will allow us to study the broader environment of the star forming clouds, constrain the time scales for star formation and cloud disruption in this environment, and study the effects of feedback on the molecular material. The area selected for mapping has excellent ancillary data from the {\em Hubble} Tarantula Treasury Program and velocity-resolved [CII] from SOFIA. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2023-09-09T15:51:19.000 |
| 1153 | 2017.1.00005.S | 37 | The Atomic to Molecular Ratio and Shocks in the Circumnuclear Disk of Centaurus A | Centaurus A (NGC5128) is by far the nearest powerful radio galaxy and our best candidate for detailed studies of the ISM properties of the circumnuclear disk (CND), feeding mechanisms of an active galactic nucleus (AGN) and feedback on the surrounding gas. In this proposal we aim to study the atomic and shocked gas of the CND by using the atomic [CI] fine structure line 3P1 - 3P0 (492GHz) and the shock tracers CH3OH (2K - 1K) (96 GHz) and HNCO (5 0,5 - 40,4) (109 GHz) at 10 pc resolution (~0.5''), to be compared with our previous ALMA CO(3-2) and CO(6-5) maps towards the CND (Espada et al. 2017). Using APEX observations over the CND, Israel et al. (2014) found a considerably strong [CI] line compared to CO(5-4), being the ratio larger than in the majority of starburst/AGN nearby galaxies. With the observations here proposed we will: 1) investigate the properties of the atomic gas versus the molecular gas within the CND, 2) to confirm or refute the existence of an atomic outflow component that has been recently proposed (Israel et al. 2017), and 3) to study the location and properties of shocked gas as produced by non-circular motions. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-02-15T12:58:38.000 |
| 1154 | 2019.2.00015.S | 9 | Wide-Field CO Survey of 4 Metal-Poor Dwarf Galaxies | We propose to map 4 nearby, very metal-poor star-forming dwarf galaxies, with metallicities 0.08-0.2 Zsun, in the CO(2-1) line. This survey at high spatial resolution (13-70 pc) will enable the systematic detection and characterization of molecular clouds. The survey is designed to address fundamental physical questions pertaining to star formation: (1) Where is the CO-emitting gas in very metal-poor dwarf galaxies? (2) How are the formation and destruction mechanisms of molecular clouds in dwarf galaxies modified? (3) How is star formation altered in metal-poor environments? Solutions to these questions will have far-ranging implications for star formation and galaxy evolution research. These proposed observations would be a pilot and proof of concept for an ALMA Large Program targeting a more complete sample of nearby dwarf galaxies. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-11-18T14:49:03.000 |
| 1155 | 2012.1.00729.S | 5 | Millimeter and Submillimeter Spectrum of 3C 454.3 in the Close Vicinity of the Central Engine | We propose to observe continuum spectrum of 3C 454.3, a representative of blazars, in 5 frequency bands. Goal of this proposal is to identify the optically-thick to optically-thin transition of the emission from the jet in the close vicinity of the central engine. Our preparatory study indicates that this source shows the transition around ALMA band 3 or band 6, while the previous one-zone SED modeling predicts the transition in far-infrared bands. An alternative model, which can reconcile this discrepancy, is multi-zone scenario such as stratified jet model, i.e., the high energy gamma-ray emission from the spine and radio emission from the sheath of the jet. This will give a new understanding for the anatomy and particle acceleration theory in AGN jets. Determination of the transition requires very accurate spectral measurement. Thus, we request to carry out the observation in 5 frequenciy bands (one for band 3, two for band 6, and two for band 7) to minimize the systematic error caused by the flux calibration inaccuracy. Since this source shows a rapid time variation with a timescale of days to weeks, multifrequency flux measurements must be done quasi-simuiltaneously. This can be done with sequential mode observation, which is firstly offered in ALMA Cycle 1. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2015-10-06T11:27:39.000 |
| 1156 | 2022.1.00064.S | 200 | Feeding BEARS at Cosmic Noon | Cosmic Noon (redshift z~2), when the Universe was 3 Gyr old, is when the volume-averaged star formation (SF) density in the Universe peaked, when most of the Universe's metals were created, and when the supermassive black hole growth was greatest. This epoch was radically different to today. Ultraluminous galaxies (ULIRGs, >1e12 Lsun) were in the main sequence of sustained star formation, whereas at z=0 they are negligible for the SF budget and exist in starburst (ie intermittent) mode. SMGs at Cosmic Noon contributed tens of percent to the overall cosmic SF. The Bright Extragalactic ALMA Redshift Survey (BEARS) are the brightest SMGs at Cosmic Noon & the best examples to illuminate the triggering & fuelling of SF. There are 25 z~2 SMGs with CI 492GHz data for which we request ACA band 6 data of gas masses (via CI 809GHz) and star formation rates (via H2O) to measure: molecular gas fuel; gas consumption timescales; AGN heating; positions relative to the main sequence -all testing for drivers & triggers of SMG SF at its peak. Our targets were awarded ACA cycle 8-Supp time for these followups, so we will remove any completed observations from this project before the start of cycle 9. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2024-06-02T11:10:34.000 |
| 1157 | 2019.1.00337.S | 1773 | An efficient CO survey of sub-millimetre galaxies from AS2UDS | We propose an efficient band 3 search for CO emission from 59 sub-millimetre galaxies selected from our ALMA continuum survey of the 716 SCUBA-2 sources in the ~1 degree^2 UDS field. Our targets comprise 29 ALMA-located sub-millimetre galaxies brighter than S_870>7.5mJy (none of which have spectroscopic redshifts), along with a comparison sample of 30 fainter (S_870~3.5mJy) sub-millimetre galaxies which have precise spectroscopic redshifts putting CO into the tunings for the flux-limited sample. Together these 59 galaxies represent a population which makes a major contribution to the extragalactic far-infrared/sub-millimetre backgrounds and hence the obscured star-formation rate density in the Universe. Our sample provides an unique laboratory to investigate the evolution of the cold gas mass function of galaxies and to relate the gas content, gas depletion timescales and properties of galaxies to the evolution of the star-formation rate density at z~1-5 and the formation and evolution of some of the most extreme star-forming galaxies which have ever existed. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2022-04-22T11:04:47.000 |
| 1158 | 2023.1.01450.S | 0 | NOSH: The Neutral Oxygen Survey at High-z | We propose the Neutral Oxygen Survey at High-z, NOSH, that will use 34 hours of ALMA 12-m array time to observe the [OI] 145 micron line in 26 galaxies with existing [CII] 158 micron detections between z ~ 3 and 7.2. The [CII] and [OI] lines are the primary coolants of the warm neutral-medium in galaxies. While the [CII] line has been observed in hundreds of high-z galaxies, the complementary [OI] observations at high-z are missing. NOSH will provide these missing [OI] observations by targeting 12 and 14 sources in a low and high redshift bin, respectively, that fully span the observed [CII]/FIR ratios from ~0.0002 to ~0.004. Combining NOSH [OI] detections with the existing [CII] detections is a unique probe of the ISM in galaxies, letting us constrain the total gas cooling, gas density, far-UV field strength and spatial extent of star formation in each source. We will reveal whether star formation in NOSH sources is compact--powered by mergers--or extended with large gas reservoirs and gas accretion. The wide redshift coverage of NOSH lets us trace evolution of these galaxy properties across cosmic time, providing important new insights into high-z systems. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2025-10-01T12:05:49.000 |
| 1159 | 2015.1.00807.S | 12 | Unveiling the nature of the reddest submillimeter sources in lensing cluster fields | We propose to unveil the nature of very red submm sources discovered in four out of 10 Herschel Lensing Survey (HLS) clusters followed up at 870microns with LABOCA. Undetected in the Herschel bands, these sources may be the first submm selected galaxies with moderate intrinsic luminosities (LFIR<10^12 Lsol) at very high redshifts (z>5) or low luminosity cold dusty galaxies with Td<25K. Measuring their luminosities and redshifts will put important constraints on the density of normal dusty star forming galaxies beyond z=4 and on the fraction of dusty star formation occuring in cold galaxies at lower redshift. Mapping at 1.1mm with a sensitivity of 0.1mJy will allow us to detect these sources with S/N>10 as well as any other lensed galaxy with an intrinsic LFIR>10^11 Lsol up to z=10, and enable us to unambiguously identify their counterparts, estimate their redshift, and constrain their FIR luminosity and dust temperature. The core of massive galaxy clusters are the site of many astrophysical processes, and the data would further serve a number of ancillary purposes that we discuss in the text. Resubmission of 2013.1.01119.S which started in Cycle 2 but no data delivered to date. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-06-30T14:41:18.000 |
| 1160 | 2016.1.00282.S | 117 | CH+ lines in starburst galaxies at redshift z=2~4: probes of massive turbulent gas reservoirs | Turbulence is a critical process in the growth of galaxies in the early Universe. Whether it is fed by gas infall, stellar or AGN feedback, turbulence acts as a long-lived mass and energy buffer. The unique properties of the CH+ cation make it a robust tracer of turbulent dissipation and energy injection rate. In our Cycle 2 project, we detected the first CH+(1-0) lines in 7 strongly-lensed starburst galaxies at redshifts ~2. Deep absorptions reveal hidden massive reservoirs of turbulent low-density gas that can sustain the high SFR. Extremely broad emission lines trace major energy releases, the origin of which is open. This proposal is designed to further grasp the origin of turbulence. We will 1) extend the sample with 8 starburst galaxies over a broader range of redshifts and SFR, with and without AGN signatures. This will identify the impact of stellar- or AGN-driven feedback on the CH+ lines, and 2) observe the two brightest Cycle 2 targets at higher angular resolution to localize the sites of CH+ emission. If found at the outskirts of the dust continuum images, they would reveal large scale shocks generated by the impact of cold streams infalling upon the starburst galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-09-05T09:43:41.000 |
| 1161 | 2015.1.01058.S | 4 | Corona Australis Disk Zoo | The well clustered young stellar objects (YSOs) concentrated to the nearby (130 pc) molecular hub-filament system, Corona Australis (CrA), are by far the least explored by millimeter interferometry owing to the -37 deg Decl. Their wide ranges in disk initial conditions, ambient environments, and evolutionary pathways are ultimately linked to a diversity of planetary systems. The proximity of CrA now permits taking full advantage of ALMA's imaging capability to survey a large number of YSOs with good sensitivity and spatial resolution. We propose to resolve the gas and dust content of all 43 known protoplanetary (Class II) disks in this region with a ~0".24 (30 AU) beam. We will make impact to the community by revealing fundamental disk properties including the dust/gas density profile, morphology (cavity, azimuthal asymmetry, and multiplicity), and gas motions including rotation, radial flows, and jet/outflow, in great details. These statistically significant, unbiased and homogeneous disk samples will achieve a mass sensitivity to 0.1 Jupiter massse in dust, and ~<0.3 Jupiter masses in 13CO/C18O line ratio, which will define a realistic parameter space for planet formation models. | Disks around low-mass stars | Disks and planet formation | 2017-12-08T13:45:14.000 |
| 1162 | 2022.1.00413.S | 42 | Water Deuterium Fractionation around the G28.28-0.36 Carbon-Chain-Rich Massive Young Stellar Object | The chemical composition around massive young stellar objects (MYSOs) is a clue for physical conditions and timescales of the early stages of massive star formation. Recent observations have revealed the chemical diversity around MYSOs; mutually exclusive carbon-chain-rich MYSOs and complex organic molecule (COM)-rich MYSOs, namely hot cores. It is essential to unveil the origin of such chemical diversity for understanding massive star formation. We propose observations of the HDO and H2(18)O lines in Bands 5 and 6 to derive the water deuterium fractionation toward the carbon-chain-rich MYSO G28.28-0.36 (G28). We will study the initial condition and formation process of this MYSO by comparing the observational results with chemical simulations. If the HDO/H2O ratio in G28 is lower than those in COM-rich hot cores, it would imply that G28 was born in a relatively warm region irradiated by UV photons. Using lines of several COMs, which can be observed simultaneously, we will determine their abundances and compare them with other hot cores. If our conjecture is true, their abundances in G28 should be lower, suggestive of short timescales of the warm-up stage. | Astrochemistry | ISM and star formation | 2024-07-27T19:11:47.000 |
| 1163 | 2017.1.00393.S | 46 | Long-baseline observations of Mira variables | Asymptotic giant branch (AGB) stars are considered to belong to the main contributors of interstellar dust in galaxies. Mid-infrared interferometric observations have shown that dust starts to form at a few stellar radii from the stellar photosphere, which is also known as the extended atmosphere. In Mira-type AGB stars, this region is thought to be dominated by non-equilibrium shock-induced chemistry as a result of periodic passage of pulsation driven shocks. However, our understanding of the kinematics, shock chemistry, and dust formation mechanisms in the extended atmosphere of oxygen-rich AGB stars is still rather preliminary. In order to test the latest shock-chemical models and hydrodynamical models against spatially resolved observations, we propose to observe the transitions of key molecular species in the complex extended atmosphere of two frequently-studied oxygen-rich AGB stars with the most extended configuration of ALMA. From this study we will learn how evolved stars and their immediate physical and chemical environments vary with pulsation phases. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2018-11-11T02:20:12.000 |
| 1164 | 2018.1.01559.S | 148 | Examination of Clumpy PDR models and Initial Conditions of Molecular Cloud Formation | With this project, we investigate small-scale structures of photo-dissociation region (PDR) to examine the clumpy PDR model as an alternative to the conventional plane-parallel model. The clumpy model can better explain the mixed distributions of atomic carbon and CO molecular gas because of larger penetration depth from the cloud surface for UV photons. Precedent CO observations with the ALMA 12m array combined with the Nobeyama 45m telescope has revealed many tiny molecular cloudlets of ~ 1000 AU scale. Although atomic cold neutral medium (CNM) is expected to have similar clumpy structures formed by thermal instability as demonstrated by numerical simulations, such inhomogeneous small atomic clouds have not been resolved yet. They are crucially important because the molecular formation and dissociation are taking place in the dense CNM that should correspond to the initial conditions of molecular clouds. Toward a cloud edge illuminated by UV radiation from nearby O-type star, ACA standalone observations in the CI line is the best to reveal detail properties of the clumpy CNM. This research would be the direct examination of the clumpy PDF model. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2020-08-09T06:47:56.000 |
| 1165 | 2015.1.00532.S | 13 | Mapping the D/H ratio of Complex Organic Molecules in IRAS16293-2422 to probe its dynamics and chemistry | Many complex organic molecules (COMs) have been detected with high abundances towards low-mass protostars. These species are thought to result from active grain surface chemistry during the warm-up phase of the protostellar envelope, and to desorb at high temperatures in the inner regions of protostars. Extremely high deuterium fractionation is a characteristic of low-mass star-forming regions. The investigation of deuterated COMs will allow to further understand the chemical pathways leading to the molecular complexity and how it depends on the evolutionary stage of young Sun-like stars. With ALMA's unique sensitivity and spatial resolution, we propose to observe several COMs and their deuterated counterparts in the two cores of the low-mass protostar IRAS16293. These data will allow to determine the spatial distribution of the COMs deuterium fractionation, to assess the dynamical and physical environment of the source and to constrain the COMs formation pathways. For that, we will compare the derived abundances of COMs and deuterated isotopologues as a function of radius with gas-grain chemistry model predictions coupled with realistic dynamical models of each core. | Low-mass star formation, Astrochemistry | ISM and star formation | 2017-10-21T02:36:48.000 |
| 1166 | 2023.1.00273.S | 0 | Investigating the Connection between Magnetic Field Morphology in Protostellar Envelopes and Disk Formation | This project aims to investigate the relationship between magnetic field structures in protostellar envelopes and disk formation. Despite previous research, the connection between magnetic field structures and disk formation remains unclear due to unresolved kinematics in the disks. To address this gap, we propose to study the polarized continuum emission in a sample of young protostars selected from the ALMA large program "eDisk" with resolved disk properties and known stellar masses. Our targets include both large and small disks at given stellar masses, likely indicating a range of magnetic braking efficiency in these sources. We aim to quantify the relationships between the misalignment, angular dispersion, and curvature of the magnetic fields in the protostellar envelopes and the properties of the disks that form from them. We will combine ALMA archival polarization data and our proposed data. Our requested noise levels and resolutions ensure detection of the polarized emission in protostellar envelopes with >7-10 independent beams. Additionally, our requested resolutions allow us to disentangle polarized emission in the disks and envelopes to avoid any contamination. | Low-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1167 | 2021.1.00709.S | 30 | First measurment of the gas surface density of a planet-forming disk | Knowing the gas surface density of planet-forming disks around young stars is a crucial ingredient for our understanding of planet formation. How the gas mass is distributed over the disk determines what kind of planet is formed (e.g. gas giant or mini-Neptune). It also directly affects the growth rate and dynamics of the dust grains and planetesimals that are the seeds of planet formation. Measuring the gas surface density from observations is difficult, due to the lack of emission from H2, the main constituent of the gas in disks. The gas surface can be measured from CO line emission, provided that the emission is optically thin and the CO-to-H2 abundance ratio is known. We propose to observe the 13CO, C18O and C17O J=1-0 lines at high (0.2") resolution to measure the gas surface density of the young disk around the luminous Herbig star HD 179218. Due to its high stellar luminosity (112 Lsun) the bulk of the disk is predicted to be warmer than the CO freeze-out temperature, resulting in a relatively constant CO-to-H2 ratio of 10^-4 throughout most of the disk. This allows us to measure the gas surface density directly from the optically thin C18O line emission. | Disks around low-mass stars | Disks and planet formation | 2023-09-05T16:37:53.000 |
| 1168 | 2016.1.00907.S | 38 | Planet-disk interactions in the HR 8799 system | HR 8799 is the only system where multiple planets have been directly imaged. These exoplanets are at large stellar separations, and are surrounded by a massive debris belt. We wish to obtain constraints on the dynamics of this system by resolving the outer belt. We propose to achieve ALMA band 7 continuum precise mapping of this debris ring. Our Band 6 observations suggest that the inner edge of the outer belt is located further out than can be inferred from Herschel data. This seems incompatible with the outermost planet HR 8799 b sculpting this inner edge, and hints at the presence of an additional distant companion. A discrepancy with the ring inclination and tentative observations of clumps likewise suggest that this debris ring bears imprints of complex planet-disk interactions. Deeper ALMA observations will constrain the geometry of this outer belt, assess the presence of clumps and their location, and open a path towards a better knowledge of the dynamical history of this system. Our findings can test current theories of planet-disk interactions. It will help make it easier to use debris disks to inform us about planetary systems, even when the planets are unseen. | Debris disks, Exo-planets | Disks and planet formation | 2018-10-03T00:00:00.000 |
| 1169 | 2011.0.00526.S | 0 | A Survey of Circumstellar Disks around Low-mass stars in the Upper Scorpius OB Association | The observed lifetime of circumstellar accretion disks around young stars places empirical constraints on the timescale to form planetary systems and on the mechanisms responsible for dissipating the gas and dust in disks. Current observational constraints on the disk lifetime are derived nearly exclusively from infrared observations. Because the infrared emission is optically thick and only tracers the disk within about 1 AU of the star, these observations can only place lower limits on the disk mass. By contrast, submillimeter continuum emission is generally optically thin and is a more direct tracer of the disk mass. In this proposal, we request time with ALMA to detect the gas and dust toward a complete sample of 24 solar-type stars in the 5 Myr old Upper Scorpius OB association that are surrounded by circumstellar accretion disks. Upper Sco is the nearest OB association at this age, and thereby provides an opportunity to obtain sensitive measurements of the disk masses at a critical evolutionary stage when accretion disks have nearly dissipated. By comparing the gas and dust properties of the Upper Sco sample with that observed in 1 Myr old star forming regions (Taurus and Ophiuchus), we can determine how the disk mass function around solar-type stars evolves over 5 Myr timescales. | Disks around low-mass stars | Disks and planet formation | 2014-01-09T15:22:00.000 |
| 1170 | 2022.1.00997.T | 40 | Direct Sublimation vs. Gas-Phase Synthesis: A Comet ToO Proposal | Comets contain ice, dust and debris left over from the formation of the Solar System. Having remained in a relatively quiescent state ever since, their compositions provide unique insights into the thermal and chemical properties of the protosolar disk and prior interstellar cloud. Detections of complex organic molecules in cometary comae are becoming routine using single-dish mm-wave observations, but the common assumption that these species originate in the cometary ice is largely untested. Recent chemical/hydrodynamic coma models point to gas-phase chemistry as a possible origin for some of these species, while salt dissociation in the coma has recently been suggested for others. We propose to map HC3N, NH2CHO, HCOOH, HNCO (and other coma gases) in a bright target-of-opportunity comet, to reveal whether these species arise directly from the sublimation of cometary ice or whether they are instead synthesized as products of gas-phase chemistry in the coma. In case Cycle 9 only brings a faint comet, we will focus on mapping the distributions of more abundant species (H2CO, HNC, CO, CS) to elucidate the behaviour of known/suspected (but still little-studied) distributed sources. | Disks around low-mass stars | Disks and planet formation | 2024-07-18T21:50:44.000 |
| 1171 | 2023.1.00879.S | 0 | Detecting z~2 heating of the circumgalactic medium via SZ effect with ALMA and ACA | We propose ALMA and ACA band 3 continuum observations to detect the Sunyaev-Zel'dovich (SZ) effect and investigate the heating of the circumgalactic medium, due to AGN feedback, during the peak epoch of black hole and galaxy assembly (z~2). We select the 10 most powerful (luminosity Lbol>10^47.5 ergs/s), radio quiet quasars at these redshifts, in which heating of the circumgalactic medium is expected to be maximised. The 12-m array observations are key to identify and subtract the compact sources from the negative, extended SZ signal, while the 7-m array will allow us to probe the most extended scales up to ~60 arcsec. We aim to provide SZ detections around individual quasars and to characterise the average SZ profile via stacking technique. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-10-09T20:07:59.000 |
| 1172 | 2015.1.00986.S | 5 | Multi-wavelength imaging of the possibly planet-induced asymmetries in a pre-transitional disc | Scattered-light imaging of several transitional discs revealed intruiging spiral-arm structures that might be tell-tale signs of planet formation. However, it is not clear whether these structures correspond to significant surface density enhancements, or whether they are minor surface scale-height perturbations. Here we propose ALMA observations on the pre-transitional disc of V1247Ori, where our recent SEEDS polarimetric imaging revealed an one-armed spiral-arm structure on scales of 200-300mas. Furthermore, at 60 mas separation, we detected with Keck aperture masking an asymmetry that moved oved 3 epochs in a pattern consistent with Keplerian motion. Our ALMA imaging in the 0.87mm continuum aims (a) to measure the density contrast in the detected scattered-light spiral arm, provide unique insights on the triggering mechanism, (b) to study the density distribution near the asymmetry at 60mas separation, resulting in conclusive evidence on whether this structure traces a disc feature or an accreting companion; and (c) to search for localized variations in the grain size distribution that might be related to dust filtration or dust trapping mechanisms. | Disks around low-mass stars | Disks and planet formation | 2017-04-04T16:20:43.000 |
| 1173 | 2018.1.00948.S | 24 | The Depletion of Dense Gas in Rapidly Quenching Galaxies | We have identified a unique sample of post-starburst galaxies in transition between late- and early-types. Such galaxies are ideal laboratories for studying how the interstellar medium evolves from star-forming to quiescent. Our work has revealed that CO-traced molecular gas remains after the starburst has ended. These galaxies lie offset from the Kennicutt-Schmidt relation, with star formation rates much lower than expected for their CO luminosities. Why have these galaxies stopped forming stars? Our ALMA observations have revealed the answer: post-starburst galaxies lack dense gas reservoirs, as traced by HCN (1--0). The HCN-traced gas is gone, while the CO-traced gas is still being depleted. We aim here to test when the dense gas reservoirs decline during the post-starburst phase by observing an additional four galaxies over a wider post-starburst age range and to deeper limits. The proposed observations will reveal whether early depletion of the dense gas reservoirs drives the rapid decline in the star formation rate. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2019-12-24T16:20:45.000 |
| 1174 | 2016.1.00360.S | 21 | SMC NGC 602: an exemplary test of low-metallicity star formation and GMC evolution. | NGC602 in the SMC wing is an isolated, very young nascent OB association, so well characterized that it can serve as a prototype to understand dense gas and molecular cloud formation, evolution, and star formation at low metallicity. The SMC is the nearest place that we can study such physical processes under conditions similar to the era of galaxy assembly. We can attain critical sub-parsec scales (1pc=3") with ALMA, resolving the dense clumps and filaments which actually participate in star formation. NGC602 likely formed from the intersection of giant HI shells 7Myr ago, with OB star formation beginning 5Myr ago and continuing today. We have studied recent and current star formation in detail with HST and Spitzer. All that is missing is knowledge of the molecular gas. We will answer questions about each stage of molecular cloud evolution and star formation, including whether there is enhanced photodissociation at 0.2-solar metallicity, whether there is mechanically triggered star formation, and whether a GMC similar to those observed in the Milky Way is even required for active star formation at low metallicity, or whether only small dense CO clumps will be revealed. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2018-01-26T00:00:00.000 |
| 1175 | 2023.1.00166.S | 0 | Is Low-velocity SiO in Massive Star-forming Regions Evidence of Relic Shocks? | SiO has long been used as an unambiguous tracer of shocked gas, but narrow-linewidth, low-velocity SiO has been observed toward star-forming regions for at least two decades. The origin of this emission remains unknown, but the two leading possibilities are 1) ongoing low-velocity (<10 km/s) shocks releasing SiO from grain mantles or 2) a previous generation of high-velocity shocks(>10 km/s) for which the gas has kinematically cooled back to ambient velocities. For a sample of 3 high-mass star forming regions with known low-velocity SiO 5-4 emission, we propose sensitive (32.5 mK), ~1.6-2.2''-resolution Band 5 mosaics of four species predicted to be enhanced in post-shock chemistry from fast (>10 km/s) shocks (NH2CHO, HCOOCH3, SO2, HNCO), one species not predicted to be chemically enhanced (CH3OH) as a control, and SiO 4-3 to further constrain the SiO emission itself. | Outflows, jets and ionized winds, Astrochemistry | ISM and star formation | 2025-05-02T17:01:29.000 |
| 1176 | 2015.1.00702.S | 13 | The Structure of the Arp 220 Disks from the Optically Thinnest Part of the Spectrum | We propose to use ALMA in the longest baseline configuration to observe the nuclei of Arp 220, the closest ultraluminous galaxy, at ~90 GHz. Doing so, we will obtain high spatial resolution kinematics of the inner disk and image the blended dust, synchrotron, and thermal continuum. Band 3 represents the most optically thin part of the continuum SED in Arp 220 and is the regime in which all three emission mechanisms play an important role. This makes it a key regime for continuum studies of the inner disk. Meanwhile bright lines in this regime offer a chance to study the poorly understood inner kinematics (dispersion and rotation) of the disks. We will use our proposed line and continuum observations to measure the dynamics of the inner (<100 pc) part of each nucleus, and --- using our matched 0.1" resolution VLA continuum maps --- resolved spectral index maps. Together these measurements will provide critical new information on the structure of the inner disks, the nature of the mass distribution, and the distribution of recent star formation and cosmic ray electrons. | Starbursts, star formation | Active galaxies | 2016-11-26T18:14:31.000 |
| 1177 | 2024.1.00043.S | 0 | A Comprehensive [CII] Survey of Herschel-Selected Starbursts at z=1-2 | Recent surveys of the most luminous massive starburst galaxies found in >1000deg2 observed with Herschel have identified a comprehensive sample of >300 sources with secure CO/CI-based spectroscopic redshifts. Here we propose to detect [CII] 158um emission from the star-forming ISM in all 41 galaxies in this sample at z=1-2 that are observable with the ACA (+8 at z=3-4 with new redshifts), complementing 102 galaxies at z=3-6 already observed in cycles 7-9, providing the (by almost an order of magnitude) largest massive starburst [CII] sample. In combination with the rich suite of diagnostics already available, this study will provide critical insight into the physical properties of the ISM that set the conditions for star formation for a statistically significant sample. Based on a subsample for which <=1kpc resolution [CII] imaging with the ALMA 12m array is available, the ACA data will also provide a critical test for the potential presence of low surface brightness emission on >10kpc scales due to an enriched cold circum-galactic medium missed by high-resolution studies, as has been suggested to exist in star-forming galaxies in the early universe by some recent theoretical work. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 3000-01-01T00:00:00.000 |
| 1178 | 2016.1.00240.S | 121 | On the brink of star formation | ALMA Cycle 2, Band 6, has provided the first detection of sub-structure in a pre-stellar core. Within the central 1000 AU, we found a core nucleus of ~0.2 Msun and unresolved clumps at scales <200 AU ('seeds'), whose nature needs further observations to be assessed, but their sole existence is challenging classical star formation theories. The 'seeds' may be compact and warm structures, heated by gravitational compression, or cold local density enhancements. To unveil their nature, we plan to observe the dust continuum emission in Bands 7 and 3. Also, our Cycle 2 observations have shown that N2D+ and DCO+ are not tracing the core nucleus, possibly because of complete molecular freeze-out, or very low ionisation degree due to reduced cosmic-ray flux. To test this, we plan to observe the volatile ortho-H2D+ and the neutral para-NH2D. The selected species will allow us to test cosmic-ray propagation theories and trace the central kinematics. This project opens up the long-awaited opportunity to study the initial conditions for stellar system formation up to unprecedented small scales and to test dynamical/chemical models of evolving pre-stellar cores. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2019-03-25T00:00:00.000 |
| 1179 | 2022.1.01433.T | 90 | Gamma-ray Burst Physics with ALMA: Direct Implications for the Explosions and Progenitors | Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, and thus serve as unique laboratories for high-energy astrophysics and compact-object formation, as well as premier probes of the high-redshift universe. Observations of GRB "afterglows" provide critical insight into the energy scale and local environment of the bursts, thereby elucidating the explosion mechanism and nature of the progenitors. However, the existing extensive optical/X-ray afterglow data alone are degenerate with respect to these GRB properties. Millimeter and centimeter observations are critical for breaking these degeneracies, but pre-ALMA GRB follow-up has yielded a mm-band detection rate of <5%. This is now being remedied with ALMA, with three well-sampled ALMA mm-band GRB light curves published to date. Here, we propose to more than double the sample with a mm-band survey comprising ALMA ToO observations of 4 GRBs, and thus begin to address key unsolved questions in GRB physics. We will support these ALMA data with VLA, ATCA, and GMRT observations, extensive optical follow-up (MeerLICHT, Gemini, Subaru, MMT, Keck), and X-ray monitoring (Swift, Chandra, XMM). | Gamma Ray Bursts (GRB) | Cosmology | 2023-10-27T11:19:07.000 |
| 1180 | 2017.1.01052.S | 51 | Mapping the Interstellar Medium of HI-Rich Galaxies at z~4 | We propose to map the [CII] emission of two z~4 star-forming galaxies previously detected in cycle 3. These galaxies were originally targeted due to the presence of a damped Lyman alpha system (DLA) in the spectrum of a nearby quasar. This makes these galaxies unique for several reasons. First, their selection based on absorption means they represent a more 'typical' galaxy at these redshifts. Second, their observed properties can be used to learn more about the difficult-to-observe DLA-galaxy connection. Finally, the kinematics of the DLA can be compared to the kinematics of the interstellar medium (ISM) of the galaxy, allowing insight into the interplay between the ISM and HI gas at high redshift. The proposed observations will have resolutions of ~1kpc and ~2kpc allowing us to spatially resolve the emission in both galaxies, and determine: 1) the dynamical mass, and 2) the velocity structure of the ISM of the galaxy. With this data we will -for the first time- provide a direct mass estimate of a galaxy associated with a high redshift DLA, and determine if the HI gas around these high redshift galaxies is inflowing, outflowing or tracing the passive circumgalactic medium. | Damped Lyman Alpha (DLA) systems | Cosmology | 2019-02-26T15:59:25.000 |
| 1181 | 2022.1.01734.S | 581 | Dust trail of planet formation - measuring grain sizes in Ophiuchus | The question of when and how fast the dust grow is at the center of studies on star and planet formation. New state-of-the-art models and observations put in question paradigm that large > 1mm grains are ubiquitous in planet-forming disks. We need to understand what are the grain properties at the earliest stages of star formation process, and how fast the grain growth process occurs. This proposal will deliver the most robust constraints on dust sizes in young protoplanetary disks for all protostars in Ophiuchus. A efficient combination of archival and new data will deliver complete coverage at 0.9, 1.3, 2.1, and 3.2 mm for scales from 5 to 600 au in radius. This will lay a cornerstone for the next decade of developments of planet formation theory. | Low-mass star formation | ISM and star formation | 2024-11-27T16:25:20.000 |
| 1182 | 2024.1.00537.S | 0 | A feverish galaxy at z > 8? ALMA band 9 as a cosmic thermometer | We intend to use ALMA band 9 to provide an accurate dust temperature of a z = 8.31 Lyman-Break Galaxy that currently only has a lower limit of 80 K. Accurate dust temperatures are fundamental to our understanding of the properties of high-z galaxies (and thus of galaxy evolution across cosmic time). An accurate temperature (fractional error of ~15%) will yield the total infra-red luminosity, dust mass and obscured star-formation rate of this unique distant source, which currently could be underestimated by an order of magnitude. Both theoretical works and preliminary observations suggest that we could be overlooking a population of galaxies with hot dust components in the early Universe, which would contribute strongly to both FIR emission and obscured SFR. Without a proper understanding of these possibly peculiar sources, cosmic star-formation rate density studies, as well as UV-to-FIR radiative transfer studies by JWST can severely underestimate the role of dust in high-z galaxies. Only the sub-mm capabilities of ALMA are able to observe the short-wavelength part of the spectrum deep enough to accurately measure the dust temperature of a z > 8 galaxy for the first time. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1183 | 2017.1.00941.S | 40 | Measuring the Chemical Composition of Molecular Gas in the Debris Disk around 49 Ceti | The surprising presence of substantial quantities of gas in some debris disks holds important clues to the timescale of giant planet formation and the composition of planets and small bodies outside the Solar System. CO has now been detected in a number of debris-bearing systems, but its origin is debated. The primary unexplored avenue is chemistry: does the molecular makeup of a gas-bearing debris disk resemble a protoplanetary disk, a comet, or something else entirely? We propose to perform a deep search for five molecules (CN, HCN, HCO+, SiO, and methanol) that are likely to be abundant in evolved disks. Their chemical properties will help us to distinguish not only between a primordial and secondary scenario, but also between several of the proposed mechanisms underlying the secondary production of gas in debris disks (e.g., collisional sublimation of small grains vs. photodesorption of comet-like material). We propose to target the disk around 49 Ceti, one of the brightest and best-studied gas-bearing debris disks. Its relatively high gas densities and excitation temperatures make it a prime target for revealing the molecular makeup of this enigmatic evolutionary stage. | Debris disks | Disks and planet formation | 2019-06-25T16:23:37.000 |
| 1184 | 2018.1.00682.S | 45 | Eccentric wide hot-subdwarf binaries: Testing the circumbinary disk hypothesis | Hot subdwarf (sdB/O) stars are evolved core-helium-burning stars with exceptionally thin hydrogen envelopes. Wide sdB/O binaries are formed through stable Roche-lobe overflow (RLOF) on the tip of the red-giant-branch. Contrary to theoretical models which predict cirularization before the onset of mass loss, observations show that the majority of wide sdB/O binaries have significantly eccentric orbits. One of the main unknowns during the evolution of these post-RLOF systems is the formation of a circumbinary dusty disk during the mass-loss phase. The interaction of such a disk with the binary is the only mechanism that can explain the observed high eccentricities of wide sdO/B binaries. Although there is plenty of circumstantial evidence for the existence of such a disk, no direct detection has been attempted untill now. With this proposal we will attempt the first direct detection of a CB disk around wide hot subdwarf binaries. The results will be used to test the current binary interaction models requiring such a disk, while derived dust masses will be used to further refine these models. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2020-07-26T14:14:19.000 |
| 1185 | 2018.1.00285.S | 26 | A 100 parsec View of a Molecular Outflow at Redshift 5.3 | The energetics of feedback processes are critical unknowns in models of galaxy evolution - energy from supernovae and AGN are input in ad hoc manners below the resolution limit of simulations. Outflows of gas are one consequence of feedback, and are ubiquitously observed in galaxies across redshifts. The recent detections of massive *molecular* outflows has spurred speculation that winds can halt star formation by removing the star-forming gas. Simulations of winds, however, find it virtually impossible to accelerate molecular gas to the observed velocities without destroying it, leading to the idea that molecules must re-form out of hotter wind material once the wind expands and cools. We have begun a survey of molecular outflows in dusty galaxies at z=4-5.5, so far detecting a wind in every source observed. The observations yield kpc-scale maps of the outflows, but we expect substantial substructure on finer scales. We request ~0.1" resolution observations of one source, reaching 100pc effective resolution. We will discern the origin of the molecular gas in the outflow, in order to determine the connection between molecular winds and the suppression of star formation. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2020-11-27T21:08:58.000 |
| 1186 | 2018.1.01332.S | 18 | Constraining the dust properties and radiation field in a lensed z=8.38 galaxy | Understanding the origin and evolution in the dust content of early galaxies represents a fundamental quest for which ALMA is supremely well-suited. In Cycle 3, we spectroscopically-confirmed a z=8.38 lensed galaxy selected in the HST Frontier Fields survey, detecting its dust continuum and [OIII]88mu emission in Band 7. This allowed us to place the first constraints on the dust mass and earlier chemical enrichment history for a galaxy that is possibly only 200 Myr old. However, the significant dust mass appears at variance with limits obtained for other high redshift galaxies. In addition to pending measurements of [C II]158mu emission in Band 5, we propose to target the diagnostic line of [NII]122 mu to determine the nature of the radiation field in this galaxy. The proposed observations will also provide a third measurement of the dust continuum spectrum, significantly improving diagnostic measurements of this unique early source. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-08-08T11:08:25.000 |
| 1187 | 2017.1.01662.S | 14 | Measuring the Size of a Newly Discovered Dwarf Planet | All of the 20 largest Kuiper Belt Objects have been observed thermally, allowing their basic sizes to be known. We recently discovered the eighth intrinsically brightest KBO, 2013 FY27, likely making it one of the top 10 largest KBOs. This makes 2013 FY27 by far the largest KBO without a measured sized. 2013 FY27 is extra interesting because its size is likely in the transition region. The largest few KBOs seem to have higher albedos and densities than smaller KBOs, of which 2013 FY27 is likely near the start of this transition. In addition, all the KBOs that are likely larger than 2013 FY27 have known satellites, except for Sedna, while the smaller KBOs satellites are not as prevalent. We propose to measure the thermal emission of 2013 FY27 for the first time with ALMA to see if this transition sized dwarf planet has an albedo like the largest few KBOs or is darker like the more moderate sized KBOs. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2019-01-31T18:33:08.000 |
| 1188 | 2021.2.00084.S | 0 | Revealing large-scale structure of molecular clouds in a low-metallicity environment of the outer Galaxy | The results of Herschel Gould Belt survey for nearby clouds strongly suggest that there is a direct connection between the IMF and density fluctuations in the cloud filaments. A next question to be addressed is whether this is also the case in a low-metal environment, which will help us to understand the star formation in the early universe. The ultimate goal of our study is to obtain the Core Mass Function and density fluctuations of filaments in the low-metal environment and compare them with IMF, but it is essential to identify dense parts of the clouds beforehand by a guide map covering a wide-field of view. We therefore propose to observe molecular clouds associated with an HII region in outer Galaxy with 7m-Array+TP. Three lines of CO in Band 6 will be observed. Each isotopologue will trace distinct components of molecular gas, from diffuse cloud components to the densest molecular cloud cores. The angular resolution of 6.0'', corresponding to 0.24 pc at the distance to the target, is sufficient to identify the dense regions of the clouds where star-forming filaments and cores are contained. It also allows us to make Virial analysis of clumps with size > 0.5pc. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-05-08T00:00:00.000 |
| 1189 | 2019.1.00312.S | 30 | Hall effect enabling the formation of a large Keplerian disk around the protostar Lupus 3 MMS? | The Hall effect is one of the non-ideal MHD effects proposed to enable the formation of a 100 au scale Keplerian disk around a young protostar. Nevertheless, the presence of the effective Hall effect has not been observationally confirmed. Lupus 3 MMS is a candidate protostar with the effective Hall effect. It is surrounded by a 100 au Keplerian disk. Our SMA and APEX observations found that the velocity gradient in its protostellar envelope on a 1000 au scale is possibly opposite to that of the disk rotation, while in the dense core scale of 0.1 pc is in the same direction of the disk. This change in the direction of the velocity gradient from the core to disk scales is consistent with the expectation from the MHD simulations with the effective Hall effect. However, we cannot make any further comparison of the observed velocity profile with our simulations because of the limited uv coverage and sensitivity of the present SMA data. Thus, we propose to observe Lupus 3 MMS with the 12-m array and ACA. With the proposed observations, we expect to detect and resolve the changes in the velocity gradient from the core to disk (6000 to 100 au) scales, to compare with our simulations. | Low-mass star formation | ISM and star formation | 2022-10-31T09:36:38.000 |
| 1190 | 2011.0.00964.S | 0 | Clustered Massive Galaxy Formation around a z=5.3 Submillimeter Galaxy | Cosmological simulations suggest that massive galaxies at present day form in the densest regions in the early universe, predicting the existence of massive protoclusters of intensely star-forming galaxies as their progenitors at high redshift. We have recently identified such a unique region within 1.1 billion years of the Big Bang, hosting an extreme starburst galaxy (the most distant submillimeter galaxy (SMG) identified to date, forming stars at 1800Msun/yr), and at least twelve normal star-forming galaxies (LBGs, the bulk are spectroscopically confirmed, and have 1-2 orders of magnitude lower SFRs than SMGs), within a narrow redshift interval of only dz=0.002. This most distant protocluster region known is a "smoking gun" for early massive galaxy formation through hierarchical buildup, giving key importance to understanding the physical properties of its member galaxies and the three-dimensional structure of the region in great detail. This proposal aims to add an essential missing piece to our comprehensive dataset on this proto-cluster by mapping out its core region in [CII] and rest-frame far-infrared continuum emission, using the ALMA early science array. This will critically constrain the neutral interstellar medium (ISM) content, excitation, distribution and kinematics of the central six LBGs (which, including the SMG, are situated within a single ALMA primary beam FWHM), constituting the fuel for their star formation, and dust-obscured star formation rates. This will also yield unprecedented constraints on the star formation law at z=5.3, and will enable the first direct ISM studies of LBGs at z>3. The [CII] measurements will give an order of magnitude more precise redshifts, substantially constraining the 3D structure of the protocluster. | 2013-08-06T15:41:00.000 | ||
| 1191 | 2018.1.00622.S | 51 | To explore wind-driven component in HH 111 protostellar outflow | HH 111 is a text-book example of a protostellar outflow. It has a highly collimated jet and a wide-angle outflow shell. The jet is coming from the accretion disk. However, the driving mechanism of outflow shell is still unclear. Previous study shows that in addition to the jet, a wide-angle wind is also needed to drive the outflow shell. This is consistent with current jet-launching models, which predict a wide-angle tenuous wind component surrounding a collimated jet. In order to confirm this, we need to perform accurate mass-velocity and position-velocity analyses of the outflow. The outflow can be traced by 12CO. In order to estimate the mass accurately, we need to observe the outflow not only in 12CO but also in its isotopologues (13CO and C18O) for optical depth correction. In addition, since previous observations did not have short enough uv-spacing and suffered from the missing flux at low velocity, we also need to restore the missing flux at low velocity. Therefore, we propose for high-sensitivity ACA observation of this outflow in Band 6 in order to obtain accurate mass-velocity and position velocity analyses, and thus confirm the presence of wide-angle wind. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2020-07-26T17:44:02.000 |
| 1192 | 2018.1.01783.S | 90 | Detecting carbon monoxide and neutral carbon in low metallicity dwarf irregular galaxy Sextans A | Tracing molecular gas in low-metallicity galaxies has always been a difficult prospect, but recently [CI] has been predicted to exist in precisely such environments and potentially do a better job of tracing pre-star forming gas than CO. To test whether this is the case, we identified Sextans A -- a nearby, low-metallicity dwarf galaxy exhibiting a range of cold gas properties, very recent star formation, and a single dish detection of CO at the peak of the FIR emission -- as the ideal testbed to further map CO and search for [CI]. We propose two mosaics with the ACA to completely image two recently star forming regions in Sextans A in CO (1-0) with excellent surface brightness sensitivity; such maps will already have great legacy value, especially as the CO (1-0) detection is extremely likely given previous IRAM observations. However, being able to move forward with well-informed testing of the [CI] predictions in precisely this environment will be even more valuable, so we also propose to begin the search for [CI] in this galaxy in two smaller mosaics centered on the HI column density peaks, where the current bursts of star formation are most likely to continue. | Dwarf/metal-poor galaxies | Local Universe | 2020-02-05T20:54:26.000 |
| 1193 | 2023.1.00322.S | 0 | Water BEARS | We propose a comprehensive study of water lines in the brightest sub-millimetre galaxies (SMGs) on the Southern sky from the Bright Extragalactic ALMA Redshift Survey (BEARS), more than tripling the number of H2O detections in SMGs, in order to measure star formation rates (SFRs) and test for drivers of starburst mode vs main sequence stellar mass assembly in the ramp-up to Cosmic Noon. Water is the most abundant molecule in star-forming galaxies after H2 and CO, and is an important coolant of warm gas with line luminosities comparable to CO. The H2O transitions are driven by pumping from far-IR photons, so the H2O line luminosities correlate linearly with far-IR luminosity and are hence the best tracer of SFR over >3 orders of magnitude. The H2O and CO line profiles are very similar, and resolved CO and H2O studies show they are co-spatial, implying that gravitational lens magnifications derived from CO morphologies can be applied also to H2O lines, and that differential magnification between H2O and CO can be neglected. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2025-07-18T10:57:08.000 |
| 1194 | 2012.1.00584.T | 0 | Probing Electron Acceleration Mechanism in Nearby Core-Collapse Supernovae | Identifying the site(s) of the particle acceleration and cosmic ray production has been an intensively studied field of particle astrophysics. The most promising mechanism requires the existence of a strong shock wave - in the standard scenario (`diffusive shock acceleration (DSA) mechanism'), particles gain energy through repeated collisions between up- and down-streams of a shock wave. There is however a key issue in this picture – how the particles are injected into the acceleration site. This is especially a big issue if one considers electrons, known as the `electron injection problem’ – due to the small mass and small gyro radius, they are not easily able to cross the shock wave as is required by the DSA mechanism unless their energies exceed at least 100 MeV. Exploring how the electrons behave around this energy scale at the shock front is of essential importance to clarify the acceleration mechanism of electrons. Studying synchrotron emissions from young supernovae (SNe) sheds light on the issue. The hydrodynamic interaction between the expanding SN ejecta and circumstellar materials (CSM) creates a strong shock wave, accelerating electrons, producing synchrotron emission, as is similar to SN remnants. Young SNe are however unique in an observational potential as compared to SN remnants. Due to strong magnetic field content at the shock (an order of Gauss), for given frequency we can probe electrons with much lower energy than in SN remnants (in SN remnants, radio emissions are produced by electrons with the energy > 1 GeV). Indeed, radio observations (in cm wavelengths) of nearby young SNe have shown that the acceleration is not as efficient as predicted by the DSA mechanism in the energy below ~ 100 MeV. We propose ToO observations of one nearby core-collapse supernova (SN) at Band 3, 6, and 7 in three epochs – the first observations at about three weeks after the explosion, and then additional two epochs separated by about 3 weeks each. The total observing time including the overhead is estimated to be 7.3 hrs (Note that the time estimate by the OT is for a single epoch). A main goal is to constrain the electron acceleration mechanism at a shock wave. The synchrotron emission from young SNe in the ALMA bands probes the relativistic electron population at the energy of ~ 100 – 500 MeV, which has been unexplored in similar environments (SNe and SN remnants). In this energy range, we expect to see for the first time a transition from inefficient to efficient acceleration in the standard DSA theory of the particle acceleration. The multi-band and multi-epoch observation is essential, as we want to identify the characteristic frequency of the `transition’ which (monotonically) changes with time. If this is identified, it provides not only a solid confirmation of the DSA mechanism for electrons, but also a strong clue to solve the electron injection problem. For the proposed set up, we expect one or two candidates every year within reach by ALMA. Our goal is not reachable by other telescopes, and ALMA is a unique telescope to investigate the so-far unexplored mm/sub-mm properties of SNe. In addition to the study on the acceleration mechanism, the ALMA data will also be used to address astrophysical properties of SNe, e.g., the shock velocity and the circumstellar density connected to the explosion mechanism and progenitor evolution. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2016-11-10T14:29:47.000 |
| 1195 | 2015.1.00914.S | 19 | CO-free Star Formation &Black Hole Activity in 3C368 at z = 1.131: Coeval Growth in the Stellar Populations and Supermassive Black Hole Mass | The z=1.13 radio galaxy 3C368 is quite unusual. It is one of the most powerful accreting black holes known, yet its strong far-IR emission suggests the presence of luminous obscured star formation as well. We detected [CII] in our ZEUS/CSO z~1-2 [CII] survey and together with 6 diagnostic O and Ne lines we find a good fit to a young starburst headed O5.5 stars. The age (6 Mys) of the starburst is similar to that of the AGN activity suggesting a symbiotic link. The link is consistent with the observed black-hole mass-stellar mass relationship and provides a method for the rapid growth of the most massive galaxies at early times. However, there is a hitch. We do not detect the CO(2-1) line here at a level of 40X lower than expected for starforming galaxies. DO all the far-IR lines arise from the NLR and/or torus instead? Our proposed 0.2'' spatial resolution [CII] imaging will delineate an AGN or starburst source for the lines. In a starburst scenario, weak CO emission implies either a low metallicity ISM or a chemically young ISM. This is addressed with the [CI] 609 um line observations. Strong [CI] emission favors a chemically young ISM, while weak emission favors low metallicity. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-02-14T21:32:44.000 |
| 1196 | 2018.1.01225.S | 143 | What is the Origin and Subsequent Evolution of Starbursts at z~2? | We propose to obtain resolved CO maps (with ~0.1" resolution, corresponding to ~0.8 kpc at the redshift of our sample) for 13 extremely luminous dusty star forming galaxies (log( L_IR/L_sun) > 12.5) at the peak epoch of star formation activity (2 | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2021-01-16T00:47:06.000 |
| 1197 | 2024.1.00029.S | 0 | A complete view of the molecular ISM in distant main sequence and starburst galaxies from CO+[CI] | The mass and excitation of the molecular gas are key indicators of how galaxies grow, whether via secular processes on the main sequence of star formation (MS) or through sudden starburst events (SB). However, for distant galaxies only average trends for bright sources are currently available, due to highly uneven coverage of multiple emission lines and dust continua. Here we propose to follow-up 21 compact and extended galaxies at z~1.5, spanning 1 dex of SFR on and above the MS to probe CO (J=1,2,4,5,7), [CI](1-0),(2-1) lines, and the underlying continua. Armed with ~8 transitions and ~9 points combing the dust SED for each target, we will (1) derive a first estimate of the intrinsic variety (and not only the average) of the gas excitation as a function of the distance from the MS; (2) test the validity of the surface density of SFR as a superior proxy of the gas properties, as theoretically expected; (3) model the gas+dust emission with a physically motivated recipe (turbulent heating), deriving robust Mgas and cross-calibrating 3 different methods. This sample will be a benchmark for future larger endeavors and for comparison with models and simulations. | Surveys of galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2025-10-18T15:29:14.000 |
| 1198 | 2018.1.01651.S | 48 | Completing a Census of 50pc ISM and Star Formation Properties in Disk Galaxies | We ask to complete our CO(2-1) mapping of the molecular ISM at 1" resolution in 18 main sequence star-forming disk galaxies. For this sample we have optical spectroscopy with the VLT/MUSE instrument at matched resolution across the same FoV, establishing an unprecedented view of star-forming sites, radiation field, massive stars (WR,SNR), etc. The powerful combination of molecular gas and star formation maps at cloud scales (~50 pc) across a diverse range of environments provides key constraints on the lifecycle of GMCs, the efficiency of star formation, and the coupling of feedback to gas. By making these measurements across a representative sample, we will learn how this physics depends on local and global conditions and ultimately affects the evolution of galaxies. 7m+TP data for the full sample and 12m-array data for 12 galaxies are in hand. A 10 hr investment of 12m-array time is needed to complete the census of molecular gas (and star formation) in nearby disks. The unprecedented high resolution and environmental diversity of the completed observations will make this a unique legacy dataset. | Spiral galaxies, Surveys of galaxies | Local Universe | 2020-01-15T22:47:08.000 |
| 1199 | 2022.1.00076.S | 216 | Dust Continuum Observations of Galaxies at z~5: Revealing the Evolution of Dust-Obscuration at High Redshift | Early observations with ALMA suggest that the dust properties of galaxies change significantly between z~3 and z~6 in the first 2 Gyr of cosmic history. While the locally calibrated relation between the infrared excess (IRX=Lir/Luv) and UV spectral slope (beta) still seems to hold on average at z~3, the sample of z~5-6 galaxies observed so far typically shows IRX values almost an order of magnitude lower than expected. This has important implications for estimates of the cosmic star-formation rate density at high redshifts, which rely on the IRX-beta relation to correct for dust extinction. Here, we propose to test the tentative evolution at z>3 with deep band-7 continuum observations of a well-defined sample of 24 massive, star-forming main sequence galaxies at z~5. Our sources are selected from the HST/CANDELS fields and have well-measured UV slopes >-1.5 providing the largest constraining power on the IRX-beta relation. These proposed observations are key to understand the evolution of the dust extinction curve and will have lasting legacy value into the JWST era. This program was already approved (B-rank), but not observed in cycle 7. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2023-10-18T10:14:53.000 |
| 1200 | 2015.1.01130.S | 16 | Molecular gas associated with the LMC Supernova remnants | We propose molecular gas observation of three supernova remnants (SNRs) in the Large Magellanic Cloud (LMC). The LMC offers a unique opportunity for studying SNRs because we can see objects without distance uncertainty and confusion by foreground or background material. We have selected three SNRs that are similar with our Cycle 2 observed SNR (N132D in the LMC) in X-ray morphology but the age and luminous bands are different. The primary goal of our ALMA observation is to detect defuse molecular slumps around these SNRs at resolutions higher than 1 pc. With this resolution, we will reveal the relation with thermal/non-thermal X-ray enhancement with shock interaction by comparing clumpy molecular gas with filamentary X-ray of Chandra. We will clarify the universality of X-ray emitting mechanism around the SNRs by compare the results of three SNRs with N132D, and the galactic studies. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2018-09-28T00:00:00.000 |
| 1201 | 2015.1.00243.S | 14 | First mm-observation of a disk around a free-floating planet | We propose the first mm-observation and characterization of a disk of a free-floating planet. These cutting-edge observations will open a new domain of ALMA science of the exploration of disks of (free-floating or bound) planets. We propose ALMA observations of the free-floating planet OTS44. We showed that it is the coolest and least massive free-floating planet (~12 Jupitermasses) with a substantial Herschel-detected disk that is actively accreting. We propose to observe the thermal continuum emission of this faint source with ALMA in 2 bands (0.74 and 1.3 mm) to probe for mm-sized dust grains in the disk and to accurately determine the disk dust mass (not possible with Herschel). This study of disk physics in an extremely low-gravity and -temperature environment will crucially constrain models for dust evolution in proto-planetary disks. We will address the question if grain growth, as the first step of planet formation, can occur in a disk of a free-floating planet. This would show that the process that forms planetary systems like our own works all the way down to small-mass planets orbiting Super-Jupiters. That would be key information for star and planet formation theories. | Disks around low-mass stars | Disks and planet formation | 2017-07-11T16:15:55.000 |
| 1202 | 2017.1.00215.S | 24 | Debris disks around UCDs, what lies beyond TRAPPIST-1h? | The discovery of seven planets around TRAPPIST-1 hints at the possibility that the majority of the habitable planets could orbit low mass stars. However, we know little about how and where these formed, leaving unconstrained the possibility of having an atmosphere or water. We propose to observe this system with ALMA to search for a cold debris disk and constrain: 1) the existence of an outer belt of volatile rich exocomets that could potentially deliver volatiles to the known planets; 2) the presence of planets beyond 5 AU sculpting the disk, possibly leaving asymmetric features in the disk. These observations will also give clues on planetesimal and planet formation in the system, e.g. where planetesimals formed and disk structure that indicate if the 7 planets formed further out and migrated in or in situ from a very dense disk. ALMA is the only instrument able to detect and characterize a debris disk around TRAPPIST-1. While no disk is known yet around ultra cool dwarfs (UCDs), the proximity of this system, its edge-on orientation, and the fact it has low mass planets (which suggests a massive debris disk), makes this the best candidate for studying debris disks around UCDs. | Debris disks, Exo-planets | Disks and planet formation | 2019-10-09T17:02:10.000 |
| 1203 | 2018.A.00063.S | 320 | Localized Feedback Processes in the Galactic CMZ | Feedback is essential to describe the observed properties of galaxies. Many sources contribute to feedback, including stars, black holes, and supernovae. They release energetic photons, and inject mechanical energy, momentum, metals, and cosmic rays into their surrounding ISM. This dramatically influences the star formation efficiencies. The Central Molecular Zone (CMZ) of our Galaxy hosts some environments with dramatic feedback, like the star forming region Sgr B2 and the supermassive black hole Sgr A*. In addition, there are many less studied regions where the ISM is clearly energized by some process and the combination of those small scale regions may substantially contribute to the overall CMZ feedback processes. From our unique CMZ molecular gas temperature maps, we select eight regions with substantially increased temperature. These regions show a mix of elevated turbulence, SNe and WR stars. We propose to map the ISM in 12'x12' regions around eight of these hot spots with the ACA in a number of molecular lines. These data will trace the localized impact of feedback through measuring shocks, PDRs, elevated excitation, and through a detailed dynamical analysis. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2020-12-10T00:00:00.000 |
| 1204 | 2015.1.00397.S | 56 | Structure of Protostellar Disks from the Hot Sub-AU Region to the Cold Hundreds-AU Region | We propose a holistic study of protostellar accretion disks by combining near-IR (NIR) high-resolution spectroscopy of the hot inner region and millimeter/submillimeter high-resolution imaging of the cold outer region. The target objects are three Class I sources (IRAS 03445+3242, IRAS 04239+2436, and Serpens 2) that were recently detected in emission in the NIR of CO overtone transitions and in Na I/Ca I transitions. These lines were well resolved, and modeling with Keplerian disks provided physical parameters of the inner sub-AU region. We propose to observe these disks with ALMA in the HCO+, HCN, CS, SO, and H13CN lines. These lines can trace the kinematics and physical/chemical conditions of the outer regions of the disks and/or the infalling inner envelope (as well as outflow cavities and accretion shocks). We aim to test the consistency of disk parameters, from the inner sub-AU scale region to the outer 100 AU scale region. The overall properties of the rotationally supported disks (RSDs) constructed in this project provide an excellent opportunity to constrain the physics of accretion disks. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-03-14T19:22:33.000 |
| 1205 | 2024.1.00291.S | 0 | CO Excitation in the Brightest Strongly-Lensed Quasars at High Redshift | CO line excitation ladders are the main tool to understand the properties of the star-forming interstellar medium in galaxies across cosmic history, and the mechanisms driving them. Much effort has been spent in recent years to obtain broadly-sampled CO line ladders in nearby galaxies and the brightest strongly-lensed starbursts at high redshift. We here propose to complement these efforts by obtaining complete line ladders of a flux-limited sample of high-redshift active galactic nucleus (AGN) host galaxies. We focus on the brightest, strongly-lensed systems with S(250-350µm)>100mJy, for which this study can be carried out efficiently with the ACA. All targets except one already have CO detections, such that we can solidly estimate fluxes to "fill in" the line ladders. These observations will conclusively show whether or not the CO excitation in AGN hosts is systematically boosted by the presence of AGN radiation fields. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-11-19T13:07:53.000 |
| 1206 | 2017.1.00909.S | 45 | A first step towards calibrating SN Ia distances with H2O megamasers | The best modern measurement of the Hubble constant is based on distances measured using Type Ia supernovae. Calibration of these distances depends on a complex and multi-tiered distance ladder, which is a potential source of unrecognized systematic uncertainties. Poor calibration of SN Ia distances could be an important contributor to the current tension between locally-measured H0 and predictions based on the CMB and the standard model. Extragalactic 22 GHz water megamasers in AGN accretion disks are remarkable tools that allow us to determine one-step, geometric distances to their host galaxies. With ALMA we now have the sensitivity to apply this technique using (sub)mm maser lines. Here we propose a short program to search for 183 GHz, 321 GHz, and 325 GHz water masers from NGC 5643, a 22 GHz megamaser source which has hosted two SNe Ia in recent years. The goal is to identify the triple-peaked spectral profile characteristic of disk masers, and thereby motivate a later set of ALMA observations that will provide a precise megamaser distance to the galaxy. A megamaser distance measurement to NGC 5643 would mark the first direct calibration of the SN Ia distance scale. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-05-11T16:30:10.000 |
| 1207 | 2015.1.00861.S | 40 | Molecular gas content of EXTREME outliers from the star-forming main sequence at z ~ 1.6 | It is unclear whether the most rapidly star-forming galaxies operate in a mode of star formation dissimilar from the majority that populate the so-called Main Sequence (MS). Two scenarios are commonly considered: (1) the sudden accumulation of gas at the bottom of the potential well, due to a major merger, is causing a highly efficient conversion of gas into stars, or (2) outliers may form stars in the same mode (i.e. efficiency) as MS galaxies, but just happen to be exceptionally gas rich. We can directly test this by determining whether the star formation efficiency is different from that of MS galaxies, and if so, whether the distribution of efficiencies is continuous or bimodal. Our NIR spectroscopic survey of star-forming galaxies in COSMOS with z~1.6 using Subaru/FMOS is enabling us to identify galaxies detected by Hershel/PACS and having extreme offsets (>8X) from the MS. We propose to obtain CO measurements for 7 new targets thus reaching a final sample of 10 such galaxies with accurate spectroscopic redshifts and SFRs based on FIR luminosity that builds off our previous ALMA study and lays the groundwork for future (sub)mm studies of outliers at higher spatial resolution. | Starbursts, star formation | Active galaxies | 2017-04-13T08:59:47.000 |
| 1208 | 2021.2.00047.S | 40 | Characterising the nature of the SZ-effect imprint around four radio-galaxies | Despite being commonly evoked as one of the key ingredients shaping galaxy evolution, the star-formation quenching mechanism resulting from active accretion onto super-massive black-holes is still to be confirmed observationally. One reason may be the difficulty in characterizing such type of feedback mechanism. This proposal targets four candidates for a rare case of outflows tens of kpc away from the host galaxies leaving an imprint on the Cosmic Microwave Background (CMB; only one such case has been reported in the literature until today). We propose multi-frequency observations (Bands 4 and 6) in order to constrain the spectral energy distribution of both thermal and kinetic Sunyaev-Zel'dovich effects. This project will reveal an alternative and simple technique to characterize such powerful events, thus being a key step forward in characterizing these feedback mechanism relevant for galaxy evolution models. | High-z Active Galactic Nuclei (AGN), Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE) | Active galaxies | 2023-07-29T19:40:13.000 |
| 1209 | 2015.1.00207.S | 38 | Constraining the Formation of Massive Galaxy Clusters with Dynamics | Cosmological simulations indicate that the most massive galaxy clusters start assembling early (2.52 using various selection techniques, observational evidence in support of rapid collapse has been lacking due to complex biases and incompleteness. We recently uncovered a very massive, falmentary starbursting protocluster at z=2.47 containing seven luminous dusty star-formers and nine luminous AGN. If the lifetimes of the dusty starbursts and luminous AGN are short (~100 Myr), the only explanation for their observed volume density is simultaneous triggering across a ~4000 Mpc^3 comoving volume. Alternatively, the prevalence of such rare phenomena could be evidence that their timescales are much longer, ~Gyr. Here we propose to directly test this dichotomy by observing the structures' DSFGs in molecular gas dynamics (in CO(3-2)), which will tell us if they are, indeed, kinematically consistent with major mergers with short gas depletion timescales, or if they are dynamically more stable with larger gas reservoirs. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2018-03-12T08:32:21.000 |
| 1210 | 2013.1.01013.S | 2 | Exploring the nature of relativistic jets in neutron star X-ray binaries | We propose to observe for the first time the mm frequency emission associated with relativistic jets in neutron star X-ray binaries. This observation will allow 1) to determine the size of the jet emission region close to the neutron star without contamination from X-ray reprocessed emission from the disc or from the companion star in the X-ray binary, thereby constraining jet production mechanisms, and 2) to study the scaling of such jet emission region in neutron stars at different accretion states and compare it to that found in black hole transients. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2015-09-01T13:07:35.000 |
| 1211 | 2022.1.01428.V | 0 | Blazar Flares in Crisis at Sub-Milliarcsecond Resolution | We request a single EHT observation of a radio-flaring high-synchrotron-peaked BL Lac object that is affected by the so-called Doppler crisis. For this intriguing class of objects, previous VLBI observations have typically found sub-luminal apparent jet speeds while their bright, variable, very-high-energy TeV gamma-ray emission suggests very-high Doppler factors. Most previous VLBI observations of TeV blazars were made at comparably low frequencies and during low radio states, while the immediate response of the radio jet on the smallest scales to major flaring events has not been well studied. Here, we will do just that by capitalizing on various high-frequency radio monitoring programs that can detect such flaring events. With the proposed triggered EHT observation we will determine the brightness temperature of the 1 mm core in a flaring Doppler-crisis blazar to compare it with brightness temperatures derived from its variability shown by radio and multiwavelength light curves. Furthermore, we will determine the sub-parsec-scale jet morphology and magnetic-field configuration which is crucial in understanding particle acceleration and emission mechanisms in AGN jets. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-09-23T14:12:27.000 |
| 1212 | 2018.1.01563.S | 18 | Probing disk formation scales in the deeply embedded and young first core candidate Cha-MMS1 | When and how the protostellar disk forms are strongly dependent on the initial conditions, such that very small (~10 au) or large (~100 au) disks can be formed from the early stages. A possible precursor of the protostellar disk, the first hydrostatic core (FHSC) with a size of 5-20 au, has been shown in near all simulations to precede the formation of a protostar, but it has eluded observational identification for decades. We propose high-resolution observations (0.05") of continuum and 12/13CO at 350 GHz towards the deeply embedded and extremely young FHSC candidate Cha-MMS1. With an estimated dynamical mass of just 0.02 Msun and an outflow of 800 au, Cha-MMS1 is an ideal target to investigate these predictions. We will probe disk scales down to 7.5 au, at which fragmentation, if present, can be resolved. Moreover, the properties (morphology and driving radius) of Cha-MMS1's outflow along with the simultaneous fit of the broad SED and visibilities are two independent tests for constraining the true evolutionary state of Cha-MMS1, namely a large compact source such a FHSC or a protostar surrounded by a disk. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2021-02-13T19:35:31.000 |
| 1213 | 2017.1.01350.S | 398 | Imaging protostellar outflows - building a bridge between ALMA and JWST | We propose ALMA observations of outflows from 6 low-mass protostars, in order to image their morphology and kinematics at high (~0.4") angular resolution. The selected protostars are part of GTO observations with JWST-MIRI, for which no high-resolution observations of the outflow tracers yet exist. By combining these datasets obtained at equivalent resolution, we will pinpoint for the first time currently shocked warm gas at mid-IR wavelengths to specific parts of the cold molecular outflow cavity / jet / entrained envelope material observed with ALMA. Together, they will elucidate the relation between the slow-moving gas and fast jets, between the outflows and the quiescent surrounding gas, as well as the nature of associated shocks and relative influence between shocks, UV, and X-rays on chemistry. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-10-25T16:51:26.000 |
| 1214 | 2019.1.01117.S | 10 | Evolution of Molecular Clouds Traced by Deuterium Fractionation Ratio in M83 | Deuterium fractionation ratios have been used as an evolutionary tracer of dense molecular clouds in the Galactic star formation studies, because the ratios increase with a duration time of a dense and cold state of the molecular clouds. In this proposal, we examine the potential of deuterium fractionation ratios as a chemical diagnostic tool of molecular cloud evolution in external galaxies by the observation of DCO+, DNC, and N2D+ toward the nearby galaxy M83 with ALMA. Our previous observation toward M83 with ALMA indicates that the molecular clouds are aligned in the order of molecular cloud evolution along a steam line in a bar. Therefore, the deuterium fractionation ratios are expected to increase toward the downstream along the stream line. With this observation, we will extend the deuterium fractionation science to extragalactic studies, with which we can study the molecular cloud evolution and the star formation in relation to the galactic structure scale, such as the bar and the spiral arm, and the gas dynamics of molecular clouds. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-04-22T15:53:05.000 |
| 1215 | 2011.0.00012.SV | 0 | Science verification observation of Comet Lemmon | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Solar system - Comets, Astrochemistry | Solar system | 2016-06-24T14:02:07.000 |
| 1216 | 2024.1.01241.S | 0 | Probing the Cold Molecular Circum-Galactic Medium Around Most Luminous Type-2 QSOs at z~2 with ALMA+ACA | Massive galaxies at high-z are known to co-evolve with their circum-galactic medium (CGM). The link between CGM and the stellar growth of galaxies around Type-1 QSOs has been conducted. Nevertheless, the CGM around Type-2 QSOs remains unknown. In Cycle-11, we propose to use ALMA+ACA to study the cold molecular medium for six newly discovered ultraluminous Type-2 QSOs at z~2. These targets are the most infrared luminous Type-2 QSOs selected from a 14,000 deg^2 area and all have diffuse Lya emission from the Keck long-slit spectroscopy. We will simultaneously observe the low-density gas tracer CI 3P0-3P1 and the high-density tracer CO(4-3), to obtain the mass, extent, composition and physical properties of the molecular CGM and ISM. These observations will (1) Construct a unique view of the differences between Type-1 and Type-2 QSOs on ISM and CGM scales, by comparing the gas properties; (2) Confirm the cold accreting streams around ultraluminous Type-2 QSOs; and (3) Allow an estimation of the dust SED of Type-2s. This study will reveal the intrinsic difference between Type-1 and Type-2 QSOs and open an exciting new window for investigating obscured populations in the early Universe. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 1217 | 2015.1.01088.S | 0 | Physical and Chemical Diagnostics of A Compact Obscured Nucleus | We propose a 160 GHz spectral scan through bands 4, 6, and 7 at 0.2" resolution toward the compact obscured nucleus of the luminous infrared galaxy NGC 4418. This extremely dust-enshrouded 1e11 Lsun nucleus is in a phase of rapid evolution, either as a Compton-thick AGN with a high-Eddington ratio or a very young compact starburst. This project will complete a 200 GHz scan started in Cycle 0 and use all the diagnostic power of molecular spectroscopy and astrochemistry to characterize the hidden nucleus. Most notably, lines from radiatively-pumped vibrationally excited molecules will be used to constrain the nature of the hidden radiation source. We will also use such solid physics and astronomy basis as Kepler and Stefan-Boltzmann laws and stellar L/M and AGN Eddington ratio to physically characterize the hidden nucleus. Specifically, we will measure the size and surface(brightness) temperature of the dust photosphere, derive the nuclear luminosity, and obtain L/M using a dynamical mass from gas kinematics. The L/M ratio will constrain the nature of the hidden nucleus because stars cannot have as high an L/M as an AGN can. Seven of our 25 tunings are in the Cycle 2 queue. | Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-06-27T15:13:43.000 |
| 1218 | 2015.1.00424.S | 20 | Characterizing the disk &collimated outflow around a high-mass protostar using multi-wavelength interferometry | In spite of its importance for astrophysics, the process through which massive stars form is only poorly understood. VLTI near- and mid-infrared interferometry by our team allowed us to resolve the AU-scale circumstellar environment around the high-mass (20 M_sun) YSO IRAS13481-6124, revealing a hot compact accretion disk around this object. Perpendicular to the disk plane, we detect a molecular outflow and two bow shocks, suggesting the presence of a collimated bipolar jet. Here, we propose ALMA Band 7 observations that will allow us to resolve the disk density structure and to construct a global radiative transfer model of the source. Our radiative transfer modeling and ATCA millimeter interferometry suggests that the disk mass might be comparable to the mass of the central object, which could result in observable self-gravition effects in the disk density structure. Observing in various line tracers should allow us to detect the rotation signatures of the disk and to determine the outflow properties close to the driving source. | Disks around high-mass stars | Disks and planet formation | 2018-06-15T11:07:28.000 |
| 1219 | 2017.1.00767.S | 118 | An Unbiased Search for High Velocity Winds in local (U)LIRGs using the 7m Array | We propose to use ALMA 7m array stand alone observations to carry out a complete, flux-limited, survey of 20 equatorial (U)LIRGs in the GOALS sample. The main goal is to obtain a high SNR measurement of the CO(2-1) line in order to test for the presence of high velocity components, >500 km/s, that would indicate the presence of outflows in these sources. This will allow us to estimate the incidence of molecular outflows in a statistical sample of star forming galaxies and test for possible dependences on physical parameters such as star formation rate, presence of AGN, merger stage, etc. Molecular outflows have been shown to be potentially critical in galaxy transformations and therefore a fundamental ingredient in our understanding of galaxy evolution. This program takes full advantage of the unique 7m array as a standalone facility, will provide short spacing data for ALMA 12m observations of the sample and will greatly enhance the rich multiwavelength data available for these sources, thus ensuring the strong legacy value of this proposed dataset. | Surveys of galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2019-07-03T19:36:48.000 |
| 1220 | 2018.1.01368.S | 9 | Disecting the heart of the most massive black hole with no trace of a host at z=3.8 | We propose [CII] observations of SDSS J163909+282447.1, a luminous quasar at z=3.84 with an extreme mass of 2.5x10^10 Msun for a supermassive black hole (SMBH). Based on our sensitive near-infrared adaptive optics-assisted imaging using Subaru telescope, the stellar host is undetected to a limit of <6x10^10 Msun, an order of magnitude less than predicted by the local scaling relation. Our previous ALMA CO(4-3) observations at 0.2'' resolution indicates a molecular H_2 mass of ~2x10^10 Msun and a dynamical mass within a radius of 0.7 kpc of 7x10^10 Msun. With the SMBH and molecular gas accounting for 60% of the dynamical mass, the stellar mass limit is even more stringent at <3x10^10 Msun. This SMBH has one of the largest host stellar mass deficits known. The proposed observations will trace [CII] at 0.06'' to estimate an independent and improved (3x spatially and 10x kinematically) dynamical mass. We will also estimate the star-formation rate (SFR) from the far-infrared continuum. With the new observations, we will have all key parameters: SMBH mass, dynamical mass, stellar mass, SFR, and gas mass, for one of the most extreme quasars in the early universe. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-01-31T04:46:31.000 |
| 1221 | 2015.1.00948.S | 77 | A complete census of dust in sub-millimeter galaxies | The ALMA Cycle 0 follow-up of sub-mm sources in the ECDF-South at 345 GHz (Band7) has allowed us to pin-point the locations of sub-millimeter galaxies (SMGs), and build the most statistically reliable sample of SMGs to date, ALESS, which contains 99 SMGs with a median redshift of 2.7. We propose to complete the characterization of the IR/sub-mm SEDs of the ALESS SMGs by obtaining their total continuum fluxes at 679GHz (Band 9) and 145GHz (Band 4). These observations, combined with existing continuum fluxes in Band 7, are crucial to fully characterize the amount and physical properties of dust in our SMGs. By measuring near the peak of the dust emission (Band 9), and in the Rayleigh-Jeans regime (Band 4), we will constrain the dust masses of our galaxies at least 5 times more precisely than possible with current observations. With these properties in hand, we will test models of dust formation and growth at high-z, investigate the properties of dust grains and dust heating processes in SMGs, and derive gas masses in order to establish the star formation efficiency and gas depletion timescale in high-redshift SMGs, and eventually gain insights into their mode of star formation. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-03-11T16:11:49.000 |
| 1222 | 2017.1.01149.S | 32 | Tracing the Origins of Oxygen-bearing Organics toward Orion KL | The formation of complex oxygen-bearing organics in the interstellar medium remains elusive, in particular methanol (CH3OH) which is at the center of many proposed formation pathways. CH3OH is ubiquitous in the interstellar medium hence is often used as a reference for complex molecular abundances. Theoretical studies suggest that CH3OH is formed on the surface of icy grains from the addition of H atoms to CO. We propose to elucidate the nature of this formation by mapping the D/H ratio of CH3OH isotopologues (CH2DOH and CH3OD) toward the Orion Kleinnmann-Low nebula (Orion KL), the archetype of star-forming regions in the Milky Way. Mapping the temperature structure and D/H ratios of both CH2DOH and CH3OD will show [1] the nature of the addition of hydrogen/deuterium to CO and [2] subsequent chemical reaction at the -OH site. The proposed observations will shed light on the origin of complex oxygen-bearing organics in the interstellar medium. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-04-19T16:13:05.000 |
| 1223 | 2021.1.01188.S | 15 | CO Kinematics at Cosmic Noon: Timing the Redistribution of Metals Around Galaxies | Galaxies form in a complex ecosystem, with metal-rich and metal-poor gas cycling in, out, and around their interstellar medium (ISM) on a range of timescales. The resolved kinematics and metallicities of the ISM provide two powerful probes into this cycle. We propose to constrain the timescales that metals are redistributed around galaxies at cosmic noon with new spatially-resolved kinematics from CO (2-1) observations of five galaxies at 1 | Spiral galaxies, Galaxy chemistry | Local Universe | 2023-06-30T12:53:12.000 |
| 1224 | 2017.1.01587.S | 32 | Confirmation and structure of HCOOH toward the TW Hydrae protoplanetary disk | One of the most important questions of astrochemistry is how, when and where organic molecules and potentially prebiotic molecules are formed and could this have a bearing on the origin of life on Earth? In that context, we are focussing on the formic acid (HCOOH), that is a precursor of larger carboxilic acids, including potentially prebiotic molecules. From ALMA-Cycle 3 data, we have strong hints of its detection in the TW HYa protoplanetary disks. In the proposed observations, we intend to confirm it detection and determine its excitation properties. | Disks around low-mass stars | Disks and planet formation | 2019-03-03T15:02:09.000 |
| 1225 | 2016.1.00340.S | 17 | Pinpointing the origin of the astonishing structures seen in the HD 135344B disk | Recent observations of transition disks in both Optical Near-Infrared (ONIR) scattered light and (sub-)mm continuum emission have revealed complex structures such as spirals, rings and vortices. These are often all interpreted as the sign of ongoing planet formation, but so far no connection between the structures observed in scattered light and mm has been found. However, ALMA Cycle 1 Band 7 data of HD 135344B reveald new intriguing dust structures in the disk which show a remarkable correlation with NACO/VLT ONIR images of the same object. This unique features make it an ideal and unique candidate to investigate the connection between the micron-sized dust distribution probed in scattered light and the mm-sized dust structures observed by ALMA. Our goal is to detect so far unresolved dust substructures in HD135344 B, both close to the midplane (through Band 4 observations, at 0.062'' resolution) and close to the upper layers (through Band 10 observations, at 0.062'' resolution) in order to be able to unveil the link between scatterd light and mm structures, and to deepen our understanding of their origin. | Disks around high-mass stars, Exo-planets | Disks and planet formation | 2018-12-14T12:27:37.000 |
| 1226 | 2018.A.00062.S | 274 | Physics at High Angular Resolution in Nearby Galaxies: The Local Galaxy Inventory Continued | We propose to utilize the ACA (7m+TP) to map in CO(2-1) the full star forming disks of all yet-to-be-observed nearby, large-on-the-sky spiral galaxies in which the ACA resolves molecular cloud scales (50-100 pc). These data will provide the large scale picture of the molecular ISM in five nearby galaxies and enable key insight into the interplay between galactic environment and cloud-scale gas properties. These galaxies harbor a range of physical environments, from massive AGN to low mass flocculent spirals, and thus provide a crucial link between the Local Group (where high resolution permits study of sub-cloud scale physics) and the broader galaxy population (which includes a wider range of environments). With these data we will measure GMC properties and scaling relations, cloud lifetimes, and star formation efficiency as a function of the diverse environments found in these galaxies. The resolution, sensitivity, and spatial coverage match those of our ongoing Large Program to map the disks of more distant targets with the 12m array, and so these additional galaxies will both fold into and inform the larger sample while providing context for ongoing and future zoom-in studies. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2021-03-12T00:00:00.000 |
| 1227 | 2022.1.00479.S | 22 | Material flow from envelope to disk in the protobinary system SVS13A | Studies resolving molecular lines observations to probe the gas physics from envelope down to disk scales remain rare. They are required to improve our knowledge of the formation and evolution of multiple systems. We propose obtaining sensitive molecular line observations for the close Class I protobinary SVS13A to probe the gas kinematics along a dusty spiral connecting the envelope and a circumstellar disk. Evidence for such a flow has been obtained using NOEMA DCN, and unresolved shocks near the protostars are strongly suggested by broad line emission and high temperatures from CH3CN. Our Band 6 observations will provide an order of magnitude improved resolution in DCN, CH3CN, CH3C{13}N, and 5 selected complex organic molecules (COMs) for a detailed physical and chemical characterization of the flow and its interaction with the individual circumstellar disks. We will (1) kinematically confirm the spiraling streamer using DCN and dust emission, (2) provide the first resolved temperature map for a Class I outbursting binary using CH3CN and CH3{13}CN, which trace different optical depths, and (3) investigate the origin of the COM emission with resolved maps down to 30 au scales. | Low-mass star formation | ISM and star formation | 2024-09-15T16:48:28.000 |
| 1228 | 2018.1.01438.S | 22 | Where does high-velocity water emission originate in protostellar systems? | Water emission as observed with Herschel toward nearly every low-mass embedded protostar traces very high-velocity gas, up to 50-100 km/s from the source velocity. This was a surprise, and we still do not understand the origin of this high-velocity water in outflows. The two leading hypotheses for where this emission originates is either in the protostellar wind itself, or in shocks along the outflow cavity walls. In either case, understanding the origin of this high-velocity emission will shed light on what drives outflows in embedded Class 0 sources. We propose here to address this fundamental question by mapping out a suite of molecular tracers at 50 AU resolution toward the most prominent source of high-velocity water emission, L1448-MM. These include H2O at 325 and 183 GHz, as well as CO 6-5. By extracting local excitation conditions (H2O lines) and chemical abundances (H2O and CO) we will discriminate between outflow models, thus addressing the key question above. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2022-07-20T12:11:32.000 |
| 1229 | 2012.1.00133.S | 6 | G0.25+0.02, a molecular cloud progenitor of an Arches-like cluster: the puzzle of cold dust, hot gas | Clusters and associations are the building blocks of galaxies and the nurseries of most stellar systems. However, little is known about the formation of the most massive clusters. In recent surveys, one object, G0.25+0.02, stands out as extreme. Identified as a cold, dense, massive molecular clump devoid of current star-formation, it has exactly the properties expected for a clump that may form an Arches-like massive cluster. Our wealth of ancillary data reveals tantalising evidence that it is highly structured and, thus, may be undergoing hierarchical fragmentation. Surprisingly, while its dust temperature is very low (20 K), the detection of complex molecules that arise from hot gas suggests that the gas temperature within G0.25+0.02 may be > 50K. This discrepancy is puzzling and may provide clues as to how this protocluster formed and whether star formation can progress within it. The proposed ALMA observations will reveal the distribution, physical conditions, and kinematics of both the cold dust and hot gas within G0.25+0.02 on small scales and allow us to determine its formation history. These observations can only be achieved with the order of magnitude improvement in sensitivity and dynamic range provided by ALMA. This project is perfect for ALMA's cycle 1 capabilities; in addition to producing a visually stunning image, our team has extensive expertise in mm/sub-mm interferometry and has the track record to produce a high quality timely publication. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2021-05-24T00:00:00.000 |
| 1230 | 2017.1.01217.S | 48 | Obscured star formation of the brightest galaxies at z~8 | The recent confirmation of remarkably luminous galaxies (MUV<-22) at z=8-11 has demonstrated that galaxy formation was well underway before the cosmic reionization peak at z~9. Unfortunately, none of these galaxies were accessible with ALMA. To address this issue, we used the recent UltraVISTA DR3 data and the latest IRAC observations of the SPLASH and SMUVS programs, to compile a magnitude-limited sample of 16 ultrabright H=24-25 (MUV = -22 to -23), massive ~10^10 Msun galaxies at z=8-10 over COSMOS. Massive galaxies are expected to be significantly obscured, based on stellar population model fits, lower redshift IRX-beta relations, and theoretical models which require substantial attenuation to match the observed UV luminosity function. To test for the presence of dust, we propose ALMA 1.2 mm and 1.5mm dust continuum observations of the 8 brightest galaxies from our sample. We also tuned our setup to maximize the [CII] detection likelihood, which is high for at least two sources, given the recent results of Smit et al. (2017) on bright LBGs. These observations are vital to understand the bolometric properties of the galaxies and to compare to the prediction of theoretical models. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-09-25T13:05:46.000 |
| 1231 | 2017.1.00497.S | 2 | Magnetic field structure in the bipolar outflow driven by Orion Source I | Orion source I (SrcI) is proposed to be ejected in a dynamical encounter event 500 years ago which formed a tight binary with 20M_sun. However, recent ALMA data show that the mass inferred from rotation curves is only 5-8 M_sun and that its bipolar outflow seems unaffected by the event. This puzzle may be resolved if a magnetic field plays an important role. The curved trajectories of SiO masers (VLBI) and rotation of the outflow traced by Si18O (ALMA) hint a magneto-centrifugal disk wind. In addition, BIMA observations showed strong (~50%) linear polarization in the SiO J=2-1 v=0 maser probing the magnetic field at 0.5" (200 AU) resolution. We propose to measure the linear polarization of the SiO J=2-1 v=0 masers toward SrcI at 0.1" resolution with ALMA. The primary goal is to study whether the magnetic field structure at the base of its outflow (<100 AU) is toroidal as expected from the observed rotating/collimated bipolar outflow. The higher resolution polarization map will allow us to confirm the above prediction and to compare observed velocity/magnetic field structures with those of theoretical models. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2019-02-14T19:15:41.000 |
| 1232 | 2018.1.00692.S | 2 | High-precision polarization study of the fast variability at the base of an AGN jet | Active galactic nuclei (AGN) produce powerful jets of relativistic plasma emitting non-thermal synchrotron radiation. Recently, we have reported the first ALMA measurement of Faraday rotation at submm wavelengths from the jet base of the lensed quasar PKS1830-211. For that, we analysed dual polarization data with a differential polarization technique in which, basically, the relative difference in polarization state of the two lensed images was measured. We now propose full-polarization ALMA observations of the same object at Band 6. We will probe variability of the polarization angle on timescales of few minutes to a couple of hours, allowing us to discriminate the different models of particle-shock interaction in AGN jets, and their role in the submm polarimetry and in the production of high-energy radiation. These full-polarization observations will also allow us to confirm bona fide the validity of our differential polarimetry technique. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2020-08-27T13:54:10.000 |
| 1233 | 2023.1.00842.S | 0 | A molecular absorption line survey of the circumnuclear gas disk in group-dominant radio galaxy NGC 4261 | Cooling from the hot intra-group and intra-cluster medium is believed to be the origin of the filamentary nebulae of ionized and molecular gas seen in many group/cluster-dominant galaxies. This gas appears to fuel the AGNs of these galaxies, triggering the launch of radio jets, but in most cases forms only limited quantities of stars. Unfortunately, the state of the molecular gas is poorly known; typical beam sizes capture emission from large complexes of molecular clouds, providing only aggregate gas properties. Absorption line studies using the AGN as a backlight offer an opportunity to determine the properties of individual clouds, but to date few such galaxies have been studied in absorption and only one, Hydra A, in detail. We propose ALMA band 5, 6 and 7 observations of the nearby group-central FR I radio galaxy NGC 4261, which archival data suggest is second only to Hydra A in its potential for the detection of absorption from multiple species and transitions. We will determine the dynamical state of the clouds and discover whether, as in Hydra A, their properties are similar to those of giant molecular clouds in the Milky Way, despite their very different environment. | Surveys of galaxies | Galaxy evolution | 2024-12-15T22:10:35.000 |
| 1234 | 2016.1.00078.S | 18 | The stellar-interstellar border in globular clusters | We propose deep observations of the metal-poor ([Fe/H]=-0.72) globular cluster star 47 Tuc V3, to detect the circumstellar CO envelope in CO(3-2). Using our Cycle 1 non-detection in CO(2-1), we discovered that extreme irradiation within the cluster destroys and ionises gas and dust around the star, preventing further star formation in modern clusters, and perhaps playing a role in the peculiar abundances of some globular cluster stars. By obtaining deeper observations of V3, we aim to discover how strong this irradiation is. As a secondary goal, we also hope to obtain the first measurement of the expansion velocity of an AGB star at this low a metallicity. This will help to calibrate mass-loss rates from stars in metal-poor environments, as derived from dust column densities. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2019-05-29T06:44:44.000 |
| 1235 | 2012.1.00088.S | 2 | ALMA Exploration of Cosmic Reionization with a Newly-Discovered Luminous Star-Forming Galaxy at z=7.31 | We propose deep Band 6 observations of a very distant spectroscopically-confirmed star-forming galaxy newly-discovered by the powerful combination of Subaru imaging and Keck spectroscopy. This source, at a redshift of z=7.308, lies within the heart of the reionization era yet is bright enough for a robust detection of the diagnostic [CII] 158 micron line given ALMA's improved Cycle 1 performance. As [CII] arises from photo-dissociation regions (PDRs), its observed wavelength will provide an otherwise unattainable measure of the systemic velocity of this distant galaxy. In combination with our Lyman alpha profile and the statistics of line emission in our Subaru sample, we can secure a valuable measure of the neutral fraction of the intergalactic medium at this early epoch. To date there are no such measures at such a high redshift. The fluxes of the 1.2mm dust continuum and [CII] line will also provide valuable data on the dust content and star formation rate of this early system. These properties are key not only for understanding reionization history, but also for characterizing the nature of star formation in early galaxies by providing new constraints on the cloud density and the far-UV radiation field of PDRs. By targeting the most distant robustly-confirmed galaxy accessible with the Cycle 1 capability, our observations will showcase the dramatic possibilities with ALMA and provide the first valuable step towards future studies of galaxies within the reionization era, including those exploiting samples that we expect to be discovered with upcoming deep imaging campaigns with HST and Spitzer. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2016-02-20T14:25:20.000 |
| 1236 | 2018.1.00333.S | 20 | Mapping the Dynamics of a Multiple-merger System at z = 4.6 | At z = 4.6, WISE J2246-0526 (W2246) is the most luminous galaxy known. Previous ALMA [CII]158m observations had shown not only that it hosts a large and highly turbulent reservoir of gas experiencing an isotropic outflow, but also that it is accompanied by at least three companion galaxies within ~ 35 kpc. We have recently obtained new deep 212um continuum ALMA observations that reveal tidal tails and bridges of dust, connecting the central galaxy with its neighbors, showing for the first time the morphological signature of a multiple merger event at such high redshift. However, the dust continuum does not provide any kinematic information regarding the dynamics of the system. Thus, we request [CII] observations of W2246 at a sensitivity 5 times deeper than the existing observations, down to a [CII] luminosity of 5 × 10^7 Lsun, or equivalently to detect a SFR of ~ 2 Msun yr^-1 in the dusty streamers. The main goals of this project are to map the velocity field of the large-scale inflow of neighbor galaxies, gas clumps and filaments, and to pinpoint the location where the central SMBH may be injecting feedback into the surrounding interstellar and intergalactic medium. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2023-04-11T13:11:36.000 |
| 1237 | 2013.1.01035.S | 16 | Dissecting filaments with ALMA: Unveiling the dynamic properties of dense cores within a massive IRDC | Our aim is to measure the non-thermal contribution to the velocity dispersion, as well to gain an understanding of the internal motions of massive starless cores with respect to their envelope. To do this, we have selected a massive filamentary IRDC thought to be in an early stage of its evolution. We focus on several cores within a specified region, chosen as it is at the intersection point of several dense filamentary structures. We request 7 pointings in total towards this region at 1.3'' resolution (0.02 pc, or 4000 AU). Our primary tracer will be N2H+ (3-2), which is perfectly suited to tracing dense cores in regions such as this. We have selected several other molecular lines to strike a balance between cold, dense gas and warm, shocked gas. This is to reflect the pre- and proto-stellar core population. This project will enable us, for the first time, to link to dynamic properties of cores to that of their natal filamentary envelopes, gaining an understanding of their formation and growth. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-05-19T16:56:40.000 |
| 1238 | 2017.1.00822.S | 15 | Surveying the ISM in gas-rich galaxies at z=3-5 through the HFF cluster MACS 1149+2223 | The Hubble Frontier Fields (HFF) program has provided six well-calibrated gravitational lensing clusters which can be exploited to provide uniquely sensitive views of the formation and evolution of high-redshift galaxy populations. We have used one of the most massive HFF lenses, MACSJ1149+2223, along with JVLA to study the radio continuum and cool gas, CO(1-0), content of a sample of high-redshift galaxies at z~3-5 with unprecedented sensitivity. In this proposal we aim to complement these surveys with ALMA observations whose goal is to characterise the ISM in these young, forming galaxies. We propose deep, Band 3 observations through the heart of the cluster to search for CO(4-3) and [CI](1-0) line emission at z=3-5. In six pointings, we will map the entire critical curve, where magnification factors are as high as 100. Along with our existing JVLA CO(1-0) data, covering the same area and redshift range, these ALMA observations of lensed sources will provide unparalleled diagnostic power over the molecular gas masses and excitations in normal star-forming galaxies at high redshift. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2020-01-08T12:15:36.000 |
| 1239 | 2013.1.00668.S | 13 | Probing the Gas Excitation in high redshift Main Sequence Galaxies | Recent CO observations in normal main-sequence galaxies at high redshift have shown that their star formation efficiency is lower than in case of merger driven SMGs, more consistent with the star formation efficiency in local spiral galaxies. The picture that emerges from this studies is that SMGs form stars more rapidly because their gas clouds are more compressed so they churn more quickly through the available gas reservoir than the typical normal high-z disk galaxies. These differences in the physical conditions of the ISM are expected to affect the CO and CI line ratios. Indeed earlier studies of low-J CO transitions suggest that main sequence galaxies have similar ISM properties than the MW. A coherent picture of the gas excitation in these systems, however, is missing so far. We here aim to investigate the gas excitation in three main-sequence galaxies selected from the PHIBSS survey. We propose to study the shape of the CO SED in conjunction with both lines of atomic carbon to investigate the physical conditions of their ISM. Our study aims to provide for the first time well characterized templates of the gas excitation in high redshift main-sequence galaxies. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2015-10-16T13:24:05.000 |
| 1240 | 2011.0.00471.S | 0 | 30 Doradus: Dense Gas in the Nearest Super-Star Cluster v0.13.1 | 30 Doradus is the nearest super-star cluster, and an ideal laboratory in which to study the effects of vigorous star formation on molecular gas in galaxies. We propose to image the northern molecular cloud in 30 Doradus, showcasing the unprecedented power of ALMA, even in early science, to understand detailed physical conditions in extragalactic multiphase interstellar media. We will image the entire cloud in the most commonly used extragalactic dense gas tracers including HCN 1-0, HCO+ 1-0, and CS 2-1 (and isotopologues), measure the density, mass and gravitational support of dense starless and starforming cores. We will image most of the cloud in 12 and 13CO 2-1 and other tracers of the warm interclump medium of this starburst photodissociation region (PDR), resolving the PDR structure. In combination with our Spitzer and Herschel data, and radio recombination line images obtained simultaneously with the molecular emission, we will model the physical conditions and amount of "dark molecular hydrogen" in a real starburst PDR at reduced metallicity for the first time. Finally, we will image a small region in high-excitation lines including CO 6-5 that are particularly sensitive to conditions in the hot dense clumps of PDRs. Detailed analysis of the molecular environment of the nearest reduced-metallicity starburst will inform the interpretation of many ALMA observations, revealing the true nature of the gas emitting brightly in these lines in more distant galaxies | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2013-03-13T17:57:00.000 |
| 1241 | 2017.1.00326.S | 548 | ALMA Follow-up Survey for Clumpy Galaxies at z~0.9 in the COSMOS Field | We recently performed a systematic survey for clumpy galaxies in the COSMOS 2 deg^2 field and found that the fraction of clumpy galaxies strongly depends on specific star formation rate (star formation rate per unit stellar mass) but not on stellar mass. This discovery is consistent with the gravitational fragmentation scenario of the formation of clumpy disks. In order to confirm this scenario, we here propose submillimeter continuum observations of a sample of 30 clumpy galaxies as well as a control sample of 30 normal (non-clumpy) disk galaxies at 0.7 < z < 1.0 at Band 7 on ALMA. Our immediate objectives are 1) to estimate gas-to-stellar mass ratio of our target galaxies, and 2) to directly compare these properties between clumpy and normal disk galaxies at the same redshift range. The proposed observation provides us a unique opportunity to understand the origin of their clumpy morphology and the transition to normal disk galaxies. | Starbursts, star formation | Active galaxies | 2019-04-30T21:46:18.000 |
| 1242 | 2012.1.00090.S | 0 | The bright end of the submm galaxy counts: real or not? v1 | Recent submm interferometric studies with ALMA and SMA of bright submm sources from single-dish bolometer surveys have hinted that most of the brightest sources (850um fluxes > 10mJy) actually represent blends of several, fainter, SMGs. This would have significant implications for the number density of the most luminous SMGs, Hyper-Luminous IR Galaxies (HyLIRGs), and the use of the number counts of these bright sources to constrain theoretical galaxy formation models (which in some cases have required significant alterations to fit the potentially erroneous counts). However, the current ALMA/SMA studies comprise just ~10 submm sources and so we propose short ALMA Band 7 continuum snapshots of 30 >10mJy sources from a new SCUBA-2 survey of the equatorial SXDF-UKIDSS/UDS field. These observations of a statistically significant sample will allow us to determine the average multiplicity of bright submm sources, derive the true form of the bright source counts (necessary to constrain models) and produce uncontaminated samples of real HyLIRG SMGs for study. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2014-11-07T09:35:00.000 |
| 1243 | 2021.1.01015.S | 7 | Characterization of highly excited gas in the most distant submillimeter galaxy | We propose to conduct 0.4arcsec-resolution observations of the CO(12-11) and CO(11-10) emission lines in SPT0311-58 at z=6.900, which is the highest redshift SMG. These two lines can be simultaneously observed with a single frequency setup, doubling the efficiency of observations. The CO(6-5), CO(7-6), and CO(10-9) emission lines are detected in previous ALMA observations. Combining the proposed observations with the previous ones, we will investigate the CO spectral line energy distributions (SLED) of highly excited gas in the central 1 kpc region of the SMG at z=7. If we find the CO SLED is similar to that of the nearest quasar, Mrk231, it would be a signature of dust-obscured quasars at z=7, which have not been discovered yet. In obscured quasars, black holes grow faster than an unobscured phase. Therefore, the detailed study of the CO SLED in a SMG at z=7 would provide new insights into our understanding of the early growth of supermassive black holes. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-12-29T14:16:07.000 |
| 1244 | 2021.1.01578.S | 120 | Is accretion driven by magnetic disk winds in Class 0? | Recent numerical simulations propose that the accretion in disks is governed by the launching of magnetic winds that would extract angular momentum. During the earliest protostellar phase (Class 0), MHD disk winds would then regulate the formation and evolution of the disk and set the final mass of the growing star. Previous ALMA observations have brought first evidence of MHD disk winds in three Class 0 sources, observed as rotating outflows seen as at small scale (<150au). The time is ripe to determine if MHD disk winds are ubiquitous in Class 0 protostars or if they are the exception. We propose here to map at high resolution (~35 au) and high sensitivity (3K in a 0.25km/s channel) the base of five promising outflows emanating Class 0 sources in Perseus to seach for signatures of rotation. This pilot survey will constitute the first discriminant tests of the newly proposed paradigm that disk accretion is regulated by MHD disk winds. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2022-11-30T13:10:17.000 |
| 1245 | 2017.1.01413.S | 61 | Chemistry Unveils the Physics of Embedded Disks | Embedded disks form during the star formation process due to angular momentum conservation of infalling gas and likely represent the initial conditions for planet formation. Although more evolved protoplanetary disks are relatively well characterized, the physical conditions of their precursor embedded disks are poorly constrained. Embedded disks tend to be more massive, but density, gas temperatures and UV irradiation levels are unconstrained. We will characterize the temperatures and incident radiation fields by observing a suite of diagnostic molecular lines toward five embedded disks in Taurus (D~140 pc). To characterize the disk temperatures, we will use line ratios of H2CO J=4-3 transitions. Observations of N2H+ will determine whether or not embedded disks have a cold midplane (T<~20 K) where CO is frozen out. The radiation field incident upon the disks will be constrained with the CN/H13CN ratio as function of radius; CN is a direct product of HCN photodissociation. These diagnostic probes will enable the initial conditions for protoplanetary disk evolution (and possibly planet formation) to be characterized for the first time. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-11-15T13:55:00.000 |
| 1246 | 2013.1.00783.S | 6 | ALMA Identification of An Accreting Disk in a Proto-Brown Dwarf Candidate, L328-IRS, and Its Implication | L328-IRS as a Very Low Luminosity Object (VeLLO) is believed to be a proto-brown dwarf forming like a normal star and it may be one of the best example for studying the origin of the brown dwarf. Because a CO outflow from this source is discovered, its accreting disk is expected to exist as a main path for the accretion flow onto the proto-brown dwarf and also a launching ground of the outflow. We propose to make the first search for a disk structure in a proto-brown dwarf in C18O and 13CO 2-1 with ALMA. Finding a possible Keplerian disk and precise measurement of the dust envelope around L328-IRS from 1.2mm continuum observation will enable to discuss whether L328-IRS is a bona fide proto-brown dwarf and how the disk of a proto-brown dwarf is similarly forming compared with those of ordinary protostars. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-03-18T13:32:33.000 |
| 1247 | 2021.2.00118.S | 10 | A misaligned, asymmetric dust ring in a circumtriple disk | We will carry out Band 4 ACA observations in the dust continuum of the circumtriple disk around GW Ori. The project will serve as a supplement to a partially executed Cycle 7 proposal in Band 4, which suffers from significant flux missing due to the unexecuted short-baseline observations. Moreover, combined with the archived Band 6 data and the recently delivered Band 4 data, the proposed observations will allow us to constrain the dust grain size via spectral energy distribution modeling, and investigate the origin of an asymmetry in the dust ring revealed by previous Band 6 observations. | Disks around high-mass stars | Disks and planet formation | 2023-01-14T10:27:19.000 |
| 1248 | 2019.1.01347.S | 2 | Probing the thermal properties of the chromosphere at high resolution | We propose to improve our knowledge of the thermal structuring of the solar chromosphere by obtaining the highest-resolution ALMA observations in Band 3 (100 GHz). This will build on our earlier results by measuring the key spatial scales of the temperature variations in the upper chromosphere. Our previous analysis showed that the interpretation of the millimeter-wavelength brightness temperature needed to consider radiative transfer effects to properly understand the temperature stratification along the line of sight. The higher-resolution ALMA observations, combined with other spectral diagnostics in the optical and UV, will allow us to determine how closely coupled different regions of the solar chromosphere might be. It will also allow a more robust study of the small-scale dynamics of the chromosphere. | The Sun | Sun | 2022-10-21T14:31:14.000 |
| 1249 | 2016.1.01262.S | 132 | Caught in the act: ALMA witnesses galaxy transformation | Understanding why star formation is shut down galaxies is important for understanding their origins, the quenching mechanism, and how rapidly galaxies build up the red-sequence. The stacked far-infrared fluxes of the first robust sample of z~1 post-starburst galaxies reveal a surprising result - that quenching galaxies still have substaintial dust contents. This finding is at odds with the expectation that these galaxies have run out of gas and will enter the red-sequence in the next few 100 Myr. Using 18 hours of ALMA time we propose a study of the dust and gas properties of 9 massive, ultra-compact z~1 galaxies which are undergoing rapid quenching of their star formation. Our observations will allow us to determine whether these galaxies are devoid of gas. If we find significant gas contents, then these galaxies may rejuvenate, which will require us to revise the popular scenario in which red-sequence galaxies are formed after a single quenching episode. ALMA observations of z~1 galaxies caught in the act of transforming will help confirm or refute the rapid quenching mode of forming red sequence galaxies. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2018-07-18T05:19:31.000 |
| 1250 | 2013.1.00157.S | 21 | Revealing Binarity and the Youngest Disks in Oph | We propose a survey of multiplicity toward all known Class 0 and Class I protostars in Oph (50 sources). Using a dust continuum sensitivity of 0.1 Jupiter masses, we will probe the binarity of these sources from 15 AU out to 1000 AU, which well samples the peak of the main-sequence and pre-main sequence binary separation distributions (30 and 60 AU) toward the younger protostars for the first time. Combining with our Perseus VLA 8mm continuum survey, we will have 130 sources (great statistics) in two clouds, which will mitigate concerns of environment. This is the largest and most complete high-resolution millimeter-wave survey of protostellar binaries ever undertaken and will significantly improve our understanding of the formation mechanisms and prevalence of close binaries during the early stages of star formation. In addition, the survey will also be perfect for detecting protostellar circumstellar disks. There are currently only 2 disks in Class 0 sources known, so this project will increase the number of candidate Class 0 and I disks, help resolve the current controversy on early disk properties, and constrain disk formation scenarios that are hotly debated. | Low-mass star formation | ISM and star formation | 2016-09-23T14:38:25.000 |
| 1251 | 2022.1.01438.S | 35 | Revealing the 12C/13C ratio across the galactocentric radius through sensitive absorption detection | It has long been proposed that the 12C/13C isotopic ratio can be used as a diagnostic for the evolutionary stage of stars and galaxies. The current Galactic 12C/13C gradient by Milam et al. (2005) has been frequently used in various astrochemistry works. However, their work does not consider the contribution from CMB temperature, and the Rayleigh-Jeans approximation used in their analysis is not suitable for millimeter wavelengths. Correcting for all of these effects, we found that the values of 12C/13C ratio are up to 50% smaller than the previous ones. We propose here to measure the 12C/13C ratio through sensitive absorption observations toward five quasars. Each of the sightline has more than three velocity components, which trace gas components at different spiral arms. With the proposed sensitivity, we will be able to measure the HCO+/H13CO+ ratio at different galactocentric radii. Our aims are: 1) to reveal the Galactic 12C/13C gradient through this independent measurements, 2) to measure the fractionation effect on the 12C/13C ratio in diffuse clouds, and 3) to measure the photodissociation effect on the 12C/13C ratio. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-04-12T09:38:59.000 |
| 1252 | 2016.1.00983.S | 91 | Mass Loss from OH/IR Stars in the Inner Galactic Bulge | We propose to use ALMA to detect the 12CO J=2-1, 12CO J=3-2, and 13CO J=3-2 lines from the envelopes of 22 OH/IR stars in the inner Galactic bulge. This is impossible with a single-dish instrument due to the extended emission from interstellar molecular clouds. We will use the data to determine these stars' mass-loss rates to help measure the inner Bulge's ISM replenishment. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2017-11-16T11:15:48.000 |
| 1253 | 2018.1.00147.S | 22 | Deep Search for Galaxy Overdensities around the Highest-redshift Quasars | We propose deep ALMA Band 6 observations around the two highest-redshift quasars at z=7.54 and z=7.09 over 3'x3' corresponding to 1x1 physical Mpc2 at their redshifts down to a depth of 0.3 mJy (1.3 mm, 5 sigma). Our panoramic deep observations will enable us to examine the presence of galaxy overdensities around the luminous quasars based on their obscured view, which has been missed in previous work. We will address the following three science goals: 1) Deriving the number counts of dusty star-forming galaxies in these quasar fields, 2) Characterizing dust emission properties of UV-selected galaxy candidates at around the quasar redshifts, and 3) Unveiling the 3D structure of [CII]-emitting sources around these quasars. The combination of our proposed ALMA data, previously obtained archival data such as HST and Spitzer, and forthcoming JWST data for these highest redshift quasar fields will unveil the distributions of both obscured and unobscured star formation in possibly biased regions at high redshifts, which will be helpful to understand an early phase of galaxy evolution. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2020-08-20T15:23:51.000 |
| 1254 | 2021.A.00020.S | 40 | Confirmation of a z = 12.3 galaxy candidate | We ask for 16 hours of ALMA band 6 time to acquire the spectroscopic redshift of a robust bright galaxy candidate at z=12.3 identified in the Early Release Science Programs of the JWST. If confirmed, this galaxy would be the highest-redshift galaxy known to date and will provide strong constraints on the UV luminosity function and on galaxy formation models. We combine four spectral tunings to form a contiguous frequency coverage across redshifts 11.9 to 13.5 (covering more than 90% of the redshift probability distribution of the source), targeting the doubly-ionized Oxygen [OIII] emission. Meanwhile, these observations will provide strong constraints on the dust emission (down to an obscured fraction of 1) and internal ISM conditions (including metallicity) of a galaxy observed ~350Myr after the Big Bang. Through this high-reward proposal, ALMA will uniquely provide the essential and complementary perspective on one of the key goals of the JWST mission. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2022-08-05T11:51:26.000 |
| 1255 | 2023.1.01660.S | 0 | NGC 4945: The Milky Way's not-so-distant Cousin - ACA Standalone Mapping of the Full Disk in Band 3 Dense Gas Tracers | Star formation correlates mostly directly with dense gas, but spectroscopic tracers of dense gas are incredibly faint with low surface brightness. As a result, we still know relatively little about the resolved structure of dense gas in galaxy disks and its relation to other parts of the galaxy. To address, we propose ACA standalone mapping of the full disk of the nearest starburst+disk galaxy NGC 4945 in Band 3 dense gas tracers (8 lines in total). Our map will cover 10kpc along the major axis of the galaxy, extending previous dense gas studies of starburst systems which focus heavily on galaxy nuclei (<1arcmin^2). This will yield continuous, uniform measurements of the dense gas abundance and efficiency spanning from the starburst nucleus across the disk environments, adressing major open questions. The inclined geometry and proximity of the target and the need for surface brightness sensitivity make this a highly productive, novel use of the ACA. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2025-04-29T18:46:40.000 |
| 1256 | 2017.1.00396.S | 116 | A bright QSO at z~7.5: pushing detailed interstellar medium studies to the earliest cosmic epochs | After almost a decade of intense search, we have finally discovered a bright QSO well within the reionization epoch at z=7.5424. With NOEMA we detected the dust continuum and a bright, 300 km/s wide [CII] line in this source. The presence of a supermassive black hole, dust, and intense star formation at this redshift imposes new challenges on structure and galaxy formation. The combination of the bright [CII] emission and the redshift of this source enables an unprecedented ALMA study of 18 molecular and fine-structure lines with rest-wavelengths as short as 88um ([OIII]). Here we propose (i) high resolution (0.2", ~1 kpc) imaging of the [CII] line to constrain the morphology/kinematics of the gas to measure the dynamical mass of the QSO host, map its star formation activity, and identify signs of mergers; and (ii) target a suite of molecular and fine-structure lines that combined will reveal key physical conditions such as density, temperature, metallicity, ionization degree, and hardness of the radiation field. This remarkable QSO provides a unique laboratory for ALMA to push detailed studies of star formation and the interstellar medium to the highest accessible redshift. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-01-27T18:27:38.000 |
| 1257 | 2021.1.01210.T | 159 | A Systematic Survey of Jets and Outflows in Tidal Disruption Events with ALMA | Transient accretion onto a supermassive black hole (SMBH) through the tidal disruption of a stray star offers a unique opportunity to study the birth and evolution of relativistic jets and to probe the environment around previously dormant SMBHs on sub-parsec scales. The past few years have shown that some tidal disruption events (TDEs) launch relativistic jets and broad outflows that generate synchrotron emission peaking in the mm on timescales of days to weeks. The faintest TDE outflows seen to date are ~10^4 times less luminous than the brightest known TDE jet and remain mysterious. To understand this diversity and determine the origin of the faintest outflows requires: (i) a larger sample of TDEs from a diverse range of selection methods, and (ii) deep mm follow-up, only possible with ALMA. Here, we propose to observe up to 8 new TDE candidates with triggers from gamma-ray, X-ray, or optical surveys (e.g. Swift, Fermi, XMM-Newton Slew Survey, eROSITA, ASAS-SN, Gaia, DES, YSE, ZTF). Our mm observations will be sensitive to both non-relativistic outflows and relativistic jets and will constrain jet formation models and rate predictions, which are currently highly uncertain. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2023-06-15T21:22:12.000 |
| 1258 | 2023.1.01052.S | 0 | Molecular gas distribution and dynamics in main-sequence galaxies at the peak epoch of the cosmic star formation | Sensitive measurements of the CO emission line in high-z galaxies at sub-galactic scales are now possible with ALMA. In this pilot project, we propose to build a comprehensive sample of z~2 star-forming main-sequence galaxies observed in CO(3-2) emission. Making use of the ALMA archive and literature, we have gathered bright unresolved CO(3-2) detections for 4 galaxies to perform follow-up observations and resolve the galactic disks at ~2.5 kpc-scale. We will characterize the gas distribution and kinematics of the likely dominant component in term of mass in those main-sequence galaxies. We will measure the molecular gas extension, rotation velocity, velocity dispersion. The molecular gas extension will be compared with that of the stars constrained from HST-CANDELS, and future JWST, imaging. Available Halpha KMOS-IFU observations will enable reliable comparison between the molecular and ionized gas kinematics. This pilot project will provide clues about how galaxies build-up their stellar mass content at the peak of the cosmic SFRD, and pave the way for a future more ambitious ALMA project. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2025-11-18T11:15:17.000 |
| 1259 | 2018.1.00917.S | 319 | Monitoring the Sub-mm Brightness in the Inner Envelopes of Known Variable Deeply Embedded Protostars | We propose to use the standalone mode of the ACA to obtain band 7 continuum observations for 4 epochs over cycle 6 of three known variable protostars and 5 stable calibrator sources in the Serpens Main Cloud. The observations will take place contemporaneously with the JCMT Transient Survey, which observes the region at a two to four week cadence. The ACA observations will monitor the brightness evolution in the inner envelope where the dust responds only to changes in the source accretion luminosity. At the distance to Serpens Main of ~415pc, our ACA observations will resolve scales of ~3.8"/1580 AU and recover scales as large as ~19.7"/8175 AU, complementing the JCMT's angular resolution at 850 microns of ~14.6"/6060AU. Thus, comparison between the JCMT and ACA observations will provide critical information on the structure of the envelope, its variability, and its environment. Furthermore, any stochastic event that might occur during the cycle will manifest itself in the ACA observations weeks to months earlier than in the JCMT observations, providing an unambiguous probe of the dust response rate through the envelope. | Low-mass star formation | ISM and star formation | 2019-10-18T18:49:28.000 |
| 1260 | 2011.0.00232.S | 0 | Molecular Gas and Obscured Star-fomation in Host Galaxies of Dark Gamma-ray Bursts | We will observe redshifted CO lines in two host galaxies of dark gamma-ray bursts GRB020819 (z=0.411) and GRB051022 (z=0.807) at band 6, and simultaneously obtain dust continuum emission. GRBs are considered to occur because of the deaths of massive stars, and therefore, they are closely associated with star formation in hosts. GRBs can be detected at cosmological distances and are considered to be effective indicators for star-formation activity in the distant universe. Only a small fraction of GRB hosts have been studied for which high obscured star formation is indicated, and whether GRBs occur in dust obscured star-forming regions. The two proposed GRB hosts are the best targets for CO and dust emission observations because (a) they are actively star-forming galaxies, (b) with large dust extinction (A_V > 1.5), (c) and have high metallicity environments. If we detect the CO line, this is the first detection in GRB hosts, allowing us to examine GRB hosts in terms of molecular gas for the first time. Scientific goals of this proposal are (i) to measure the amount of molecular gas and examine whether the molecular gas mass is enough to sustain the active star formation taking place in the GRB hosts, and whether GRBs occur in gas-rich parts within hosts, (ii) to reveal obscured star formation in the hosts and examine whether GRBs occur in dust obscured star-forming region, and (iii) to derive star-formation efficiency and examine whether GRB hosts are similar to those of normal star-forming galaxies or starbursts. | Gamma Ray Bursts (GRB) | Cosmology | 2014-02-20T02:20:00.000 |
| 1261 | 2019.1.01607.S | 10 | Mass-loss and the evolution of the most massive stars in the Galaxy | Massive stars impact on fields as diverse as galactic evolution, core-collapse SNe and the birth of black holes and neutron stars; the latter particularly relevant with the dawn of gravitational wave astronomy. However we lack a complete understanding of their evolution: for a star of given mass we cannot yet predict how it will die, nor the nature of the resulting relativistic remnant. This is due to the lack of a theoretical framework for quantifying mass-loss, with evolutionary codes relying on empirical constraints which, at worst, are uncertain at the order of magnitude level. Consequently, we propose to observe the Arches and Quintuplet clusters, which contain very large numbers of very massive (>60 Msun) stars for which we may obtain mass-loss rates via simultaneous quantitative analysis of extant VLT spectroscopy, HST photometry and critically, ALMA mm-continuum observations. This will provide a unique insight into the dependance of mass-loss on properties such as stellar mass and luminosity for the most massive stars that Nature permits; essential input physics for stellar evolutionary as well as spectral and population synthesis codes. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2021-06-22T15:54:05.000 |
| 1262 | 2016.1.00231.S | 123 | Imaging the most distant and extreme starbursts in the Universe | In Cycle 3 we performed a redshift search (via scans of the 3mm band) of 27 sources where 7 of these were selected to be red based on the ratio of their 870um/500um flux ratio. This program was a great success with 55% of the sources above z>4 and with the detection of a z=6.9 source. As a part of this program we proposed to do high resolution imaging (via high-spatial-resolution 870micron continuum imaging) of these sources to determine their lens magnification. Since this data has not yet been observed and our proposal was assigned to the B category in cycle 3 we here resubmit this essential part of the program, adding eight sources to complete our sample of sources with redshifts. In 6.2 hours we will image 35 sources almost doubling our published sample (Spilker et al. 2016). Only when knowing the magnification can we determine the intrinsic properties of the sources. At redshifts approaching z=7 we are closing in on the era just a few Myr after Big Bang, and it is of profound and urgent interest to characterize the intrinsic properties of these sources since these seem to challenge the accepted models of galaxy and structure formation. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2017-12-06T09:19:35.000 |
| 1263 | 2021.1.01378.S | 24 | Probing the molecular outflows and dusty nuclei in local U/LIRGs | Molecular outflow is commonly seen in local (ultra)luminous infrared galaxies (U/LIRGs). These outflows are considered to be important in regulating star formation and the growth of galaxy nuclei. Recent observational efforts have revealed that the molecular outflows are chemically differentiated due to the shock and/or high temperature chemistry. Up to now, the elevated HCN emission has been found in a number of outflows. In such outflows, CN and CCH could also be abundant, because these species can be rapidly formed in the gas phase where C+ and H2 are abundant, even before HCN increase. We hereby propose to observe the CN (N=2-1) and CCH (N=2-1) lines toward three U/LIRGs with different properties, IRAS 17208-0014, IRAS F05189-2524, and ESO 320-G030. In conjunction with previously observed HCN, HCO+, and CO, we will characterize the chemical conditions of the outflows. Specifically, we will investigate if the distribution of CN and CCH is different from other molecular species in the position-velocity space. This will give us an insight into the evolution of gas properties in the outflow. | Outflows, jets, feedback, Galaxy chemistry | Active galaxies | 2024-02-06T06:43:05.000 |
| 1264 | 2024.1.01091.S | 0 | Understanding Little Red Dots with ALMA and MIRI | Little Red Dots (LRDs), discovered last year with JWST are a population of objects with a compact and red-coloured optical morphology and v-shaped spectral energy distributions (SEDs)/spectra. Multiple theories exist to explain the nature of these enigmatic sources, with debate as to whether the unusual continuum shape can be reproduced by an AGN alone or if it requires a hybrid galaxy+AGN model. We target 5 of the brightest LRDs that are accessible to both ALMA and JWST, and propose a joint ALMA+JWST observation to answer this question, by sampling both the mid- and far-infrared emission of these objects for the first time. We aim to measure the mid-infrared colour with JWST/MIRI around rest-frame 2-3um where the hot dust emission from an AGN would be detected if it exists. We also aim to detect the [CII] 158um line and the underlying dust continuum with ALMA, which will not only place constraints on the FIR slope, but also help us estimate gas and dust properties, obscured star-formation if any, and accurate stellar masses and AGN luminosities. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-10-11T00:00:28.000 |
| 1265 | 2018.1.00870.S | 181 | A multiphase investigation of AGN feedback | The broad scientific objective of this project is to advance in our understanding of AGN feedback and its connection with the galaxies molecular gas reservoirs. We propose to perform the first multiphase characterization of outflow properties (size, geometry, kinematics and mass) in a sample of nearby and luminous type-2 quasars (QSO2s). By combining the requested ALMA observations with available VLT/SINFONI data we will study the properties of the line-emitting gas in the ionized, hot and cold molecular phases for a pilot sample of 7 QSO2s. These AGN are drawn from a larger sample and are representative of the luminous QSO2 population in terms of bolometric and radio luminosity, morphology and SFR. We will also investigate for quasar circum-nuclear disks (CNDs) of molecular gas, characterize them and study their connection with the host galaxy via outflows. We ultimately wish to answer the important questions of whether quasars with luminous outflows differ in terms of the molecular gas reservoirs from those without outflows and/or whether there is a dependency with the outflow properties. | Outflows, jets, feedback | Active galaxies | 2020-12-17T19:46:06.000 |
| 1266 | 2022.1.01618.S | 24 | Revealing the interaction between the non-thermal point source N3 and molecular gas in the Galactic center | The non-thermal radio point source N3 is a black hole (BH) candidate near the Galactic nucleus. A peculiar compact molecular cloud (N3 cloud) is associated with N3 in appearance. Although the high temperature and broad velocity width of the cloud are suggestive of an interaction with N3, the actual relation is unclear. N3 could be an intermediate-mass BH (IMBH) with a few ten thousand solar masses that gravitationally interacts with the ambient molecular gas. In order to reveal the true nature of N3 and the N3 cloud, we propose high-resolution molecular line and continuum observations in ALMA Band 6 and 7. The principal objective is to investigate the internal kinematics and physical conditions of the N3 cloud. The possible origin of N3 is (1) a massive IMBH, (2) a micro-blazar, or (3) a background AGN. The ALMA images should enable us to distinguish which scenario is the most plausible for N3 and the N3 cloud. This project has a potential to bring new perspectives on BHs and molecular clouds in the Galactic center. | Galactic centres/nuclei | Active galaxies | 2024-07-31T13:15:41.000 |
| 1267 | 2016.1.00383.S | 31 | The Massive Protostellar Maelstrom of NGC6334I-SMA1: a Hot Multi-Core Tracing a Proto-Multiple OB System? | NGC6334I is a nearby (1.3 kpc) example of a deeply-embedded massive protostellar cluster. At the center is a Trapezium-like arrangement of four millimeter sources, two of which are prolific hot cores (SMA1 and SMA2). Our initial ALMA observations in Band 6 with a 250 AU beam have resolved SMA1 into at least four continuum components separated by ~1000 AU. This configuration suggests a "hot multi-core" in which four seeds appear to be accreting from a common gas reservoir at the core of the protocluster, possibly leading to a proto-multiple system. Two of them show compact line emission in CH3CN J=12-11, K=10 (782K above ground) while three of them appear in absorption in the low K lines. In order to further resolve the multiplicity and model the gas surrounding each protostar, including the velocity components, temperature, and density, we propose matched resolution (100 AU) imaging of a wide range of diagnostic transitions in Bands 4 and 6. In conjunction with existing VLA 1.3 cm and 7 mm images of comparable resolution, the continuum data from the line-free channels will allow us to also model the SEDs, and hence the dust mass around the individual protostars. | High-mass star formation | ISM and star formation | 2018-10-31T21:37:09.000 |
| 1268 | 2019.1.01611.S | 20 | Resolving the kinematic structure of galaxies in the first 800 million years of cosmic time | We propose deep, high angular resolution band 6 observations of [CII]158mum in two normal star-forming galaxies at z~7. These galaxies were recently spectroscopically confirmed through [CII] (at low angular resolution) and they are currently two of the four brightest known [CII] emitters in the Epoch of Reionization. With our observations we will derive the kinematics of these galaxies in a very early stage of galaxy formation and we will test if these distant systems are forming their stars in well-ordered, gas rich disks or if the sources are dominated by turbulent gas motion. This analysis will reveal if smooth accretion from the cosmic web or major mergers contribute most to the build-up of stellar and baryonic mass at z~7. We will furthermore investigate the morphology of the gas and dust and determine the offsets and spatial extend of these ISM components with respect to the stars that are visible in the rest-frame UV. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-03-03T00:00:00.000 |
| 1269 | 2013.1.00271.S | 10 | Sub-kpc Kennicutt-Schmidt star formation law in luminous infrared disks | We propose to obtain sub-arcsec resolution CO(2-1) ALMA images of two nearby Luminous Infrared Galaxies (LIRGs) covering the high-density (2-20 Msun/yr/kpc^2) regime of star-forming clumps. The galaxies are representative of the class of extended (~ 3 kpc) luminous star-forming rotating disks. Accurate star formation surface densities on ~ 0.2 kpc scales already exist based on our Pa-alpha HST imaging and Br-gamma SINFONI/VLT maps. The proposed observations will provide a direct measurement of the molecular gas surface densities of the star-forming clumps (and inter-clump medium) on scales of hundred parsec. Our extinction-corrected star formation and the ALMA-derived molecular gas densities will determine for the first time the Kennicutt-Schmidt law on sub-kpc scales for LIRGs, i.e. sampling the regime of large SF regions with high star formation surface densities. This important class of galaxies that are among the most luminous starbursts in our nearby Universe, also represent the closest analogs of the high-z clumpy star-forming extended disks. Thus the proposed observations bridge the gap between local spirals and star-forming galaxies at cosmological distances. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2016-04-22T11:59:55.000 |
| 1270 | 2019.1.01138.S | 7 | First characterisation of a multi-planetary system at the stage of formation | Many questions regarding planet formation are still open, in particular how material is accreted from the protoplanetary disk onto the forming planet through its circumplanetary disk (CPD). PDS 70 is a unique source to investigate such processes as it hosts two planetary companions within an inner cavity. These sources, PDS 70b and c, were robustly detected with SPHERE (infrared) and MUSE (Halpha). The analysis of ALMA Band 7 observations, at an angular resolution of 70 mas, indicates continuum emission at the location of the planets and represents the very first detection of a CPD. However, higher resolution observations at 30mas are required to confirm the presence of these two CPD and spatially resolve the CPD around PDS 70c from the edge of the continuum ring. In addition, substructure within the dust ring and a peak of CO emission offset from the bulk Keplerian profile strongly suggests the presence of a third companion of the disk. The requested observations would also allow for the characterization of substructure within the dust ring, required to confirm the presence of a third companion. | Exo-planets | Disks and planet formation | 2023-08-17T22:41:09.000 |
| 1271 | 2022.1.01030.S | 153 | Pinpointing the brightest, and yet elusive, submillimetre galaxies. | The bright tail of the submillimetre population is poorly understood, largely due to the intrinsic rarity of these ultra-bright galaxies with source abundances ~0.5-5 galaxies per sq. degree. We target 17 of the brightest ever found (S_850~>20mJy) SMGs, facilitated by the uniquely large area of new SCUBA2 850um observations in XMM-LSS. Our primary goals are to determine the relative contribution of source blending and gravitational lensing to the bright-end of the 850um number counts, and to robustly measure the redshift distribution for this highly-luminious population. These key observables are currently unexplored for the ultra-bright SMG population and will provide powerful constraints for galaxy formation models, which struggle to reproduce current observations. With ALMA we can robustly detect ALMA counterparts for all these single-dish sources in ~35 minutes, allowing us to efficiently constrain the multiplicity fraction. With accurate positions for the ALMA counterparts we can pin-point optical/near infrared counterparts, allowing us to derive photometric redshifts and physical properties for these SMGs via SED fitting, to uncover the true nature of this unique population. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-10-25T15:27:51.000 |
| 1272 | 2012.1.00402.S | 0 | Exploiting the synergy between early ALMA and VLT/AO-IFU | For several years it has been a challenge to study high-z star-forming galaxies using both optical and sub-millimetre spectroscopy -- a problem mainly induced by typically large dust extinctions in these systems. In this work we propose a pilot extra-galactic experiment to forge a synergy between the ALMA and VLT telescopes. We use a uniquely suited z=1.4608 star-forming galaxy selected from the HiZELS coverage in the UDS field. It is located near a bright star that aided adaptive optics (AO)-assisted integral field unit (IFU) Halpha imaging with SINFONI (0.15''~kpc-scale resolution). The IFU imaging revealed large ionised gas complexes in a rotating disk (approximately 50% of the light is in the form of clumps), allowing an estimate of inclination, asymptotic rotation speed and dynamical mass. We propose to use ALMA to follow-up these observations and measure the available reservoir of molecular gas mass via the CO(2-1) emission (in Band-3) and the spatial distribution of the cold dust (in Band-7). ALMA observations at kpc-resolution, matched to the spectral imaging, will provide key insights into the drivers of the star-formation (and its efficiency) at z~1.5, near the peak of the cosmic star-formation activity, where galaxies were assembling most of their stellar mass. | Starburst galaxies | Active galaxies | 2015-01-24T00:00:00.000 |
| 1273 | 2022.1.00519.S | 18 | Resolved, Spatially Complete Maps of Dense Gas Tracers in LMC Clouds | We request 11.1h of main array time to obtain sensitive (64mK) 12m+7m+tp maps of the emission from Band 3 'dense gas tracers' at 1pc+0.8km/s resolution across the full CO-emitting extent of five molecular clouds in the Large Magellanic Cloud. Our target clouds have existing ALMA maps of the CO isotopologues and span a range of star formation activity. We will use the data to study the spatial organization and velocity field of the dense gas within each cloud, the distributions of intensity, linewidth and line profile shape parameters for each tracer, and their relationship to the physical properties of CO-emitting structures. The proposed maps will build a bridge between highly resolved Galactic work and kpc-scale results from more distant systems, a key to understanding the physics that drives extragalactic scaling laws relating `dense gas' and star formation. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2024-11-02T15:07:56.000 |
| 1274 | 2016.1.00297.S | 55 | Search for Interstellar Pyrimidine | Many interstellar complex organic molecules are known to be prebiotically important and have essential functions in terrestrial biochemistry. Pyrimidine, the building block of nucleic acid, has been detected in meteorites and is hence a key molecule for astrochemistry and astrobiology. Given the fundamental importance of interstellar pyrimidine, we thus propose to observe nine most favorable pyrimidine bandheads and five strong low-J doublets in the Orion KL hot molecular core with ALMA in Band 7. Although the formation of prebiotic molecules in extraterrestrial environment and their contribution to the origin of life remains unsettled, the connection between interstellar organic chemistry, meteoritic pyrimidines, and the emergence of life on early Earth would be strengthened with the discovery of interstellar pyrimidine. | Astrochemistry | ISM and star formation | 2018-02-14T16:26:53.000 |
| 1275 | 2017.1.01181.V | 0 | The light-day scale structure of an extragalactic jet: 1 mm VLBI observations of Centaurus A | Joint VLBI observations with phased-up ALMA and the Event Horizon Telescope (EHT) at 1.3 mm provide the required sensitivity and angular resolution to study the jet formation region of the closest radio-loud galaxy, Centaurus A (Cen A) at scales of less than 1 light day. Due to its relative proximity (3.8Mpc), this source is a unique laboratory for investigating jet formation, collimation, and the origin and mechanism(s) of high-energy emission on the smallest scales. At a declination of 43deg, Cen A has only been poorly accessible for mm-VLBI until recently. Here, we propose a second EHT+ALMA observation to improve the uv-coverage (4h uniformly spread over different GST ranges) and to benefit from the boost in sensitivity due to 64 Gbps recording. Together with our first EHT+ALMA observation from April 2017, this allows us to confirm structure and study the inner jet evolution. We will compare the observations with predictions from dedicated Special Relativistic Magnetohydrodynamics (SRMHD) simulations, which are based on low-frequency VLBI data of Cen As jet, as well as large-scales 3D GRMHD simulations and semianalytical models. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2021-05-31T11:44:50.000 |
| 1276 | 2017.1.01628.S | 22 | Searching for CO-dark H2 gas in radio jets | Our recent discovery shows that cosmic-rays (CRs) destroy CO by converting it to CI while the H2-gas remains unaffected and challenges the widely used CO-to-H2 method in extreme environments, especially in extragalactic outflows in radio jets. These are characterized by strong magnetic fields with high densities of CRs, which makes the H2 gas to be CO-poor and CI rich. This can potentially make H2 outflows of extreme environments (AGN and starbursts) appear CO-dark. Recent ALMA detections of CO in galactic outflows indicate that H2 can exist in such extreme environments. Therefore, we propose to carry out CI 1-0 observations in the radio jets of Miknowski's Object and M87, where CO lines have been detected. We aim at i) determining the degree of CI-CO concomitance, ii) estimating the H2 gas mass in each case and iii) estimating the star formation efficiency along the outflow, to compare with the CO-based measurements. This will be a key experiment for testing our predictions that CI in both radio jets will be much brighter than in CO lines under normal conditions of H2-gas. If confirmed, it will open a new window of H2-gas detection in radio jets under extreme conditions. | Outflows, jets and ionized winds | ISM and star formation | 2019-07-13T10:04:37.000 |
| 1277 | 2015.1.01268.S | 1 | ALMA long baseline observations of DGTau | We propose Band 6 continuum observations of DG Tau at an angular resolution of 0.04"(5.6 AU). Our aim is to search for another example of concentric ring-gap structure in a protoplanetary disk, similar to those found around HL Tau by the long baseline campaign. Although several mechanisms that account for the ring-gap structure have been proposed, it is very difficult to identify which mechanism is the case based on a single example. It is also unknown whether the formation of such structure is a universal phenomenon in the early stage of classical T Tauri stars. To answer these questions, we should look at another object that enables us to make comparative studies with HL Tau. DG Tau is a promising target, bearing striking similarities to HL Tau. Even if no concentric ring-gap structure is found in DG Tau, the comparisons with HL Tau will give us informations about the conditions for the formation of such structure. The proposed observations will be an important step towards understanding of the origin of concentric gaps that should be deeply related to the formation of a planetary system. | Disks around low-mass stars | Disks and planet formation | 2017-03-02T13:42:23.000 |
| 1278 | 2023.1.00600.S | 20 | A hybrid approach to measure the 3D infall kinematics in an isolated protosellar core | Gravitational infall of gas and dust is a key process that governs the evolution of star formation. Recent discoveries of asymmetric infalling filaments challenge conventional models of infall and rejuvenate the measurements of 3D infall kinematics in protostellar envelope. BHR 71 IRS 1, an isolated Class 0 protostar, presents an ideal test-bed to study the infall process along several directions. Using two well-established methods, we would probe the infall kinematics along the line of sight and the streamers, constructing the kinematics radially and directionally. The redshifted absorption is an unambiguous signature of infall, which has been detected in HCO+ 4-3 toward BHR 71; however, its interpretation heavily relies on modeling. The same observations also hints at three distinct infalling streamers, but the optically thick emission of HCO+ 4-3 prohibits precise kinematics measurements. Thus, we propose to emipirally measure the infall along the line of sight using highly excitation HCO+ lines and trace the infall kinematics along the streamers using the optically thin H13CO+ line. This program will provide the true 3D infall kinematics for the first time. | Low-mass star formation | ISM and star formation | 2025-09-27T13:04:21.000 |
| 1279 | 2013.1.00041.S | 10 | Star Formation, Shocks, and AGN in a Pre-Starburst Galaxy Collision | We propose an ALMA CO(1-0) map plus three HCN(1-0) and HCO+(1-0) pointings of the pre-starbust interacting galaxy pair IC 2163 and NGC 2207. CO will trace the total molecular gas distribution and kinematics. HCO+ and HCN will spatially resolve excesses of dense gas to relate to nuclear flows, turbulence, large-scale shocks, and local star formation rates. Line ratios in these AGN and AGN-free nuclei will probe the link between dense gas reservoirs, nuclear star formation, and black hole activity. Starburst activity in galaxy mergers can be driven by nuclear flows, gas fragmentation, and large-scale shocks, and can be balanced by feedback from young stars and black holes. The role of these mechanisms in boosting star formation efficiency in mergers is poorly understood. This galaxy pair offers an ideal laboratory to study these phenomena. Their grazing collision has increased gas turbulence, produced Super Star Clusters and shocks, and fueled nuclear activity. It is well observed and modeled, with HST optical, SST infrared, XMM X-ray, VLA 21 cm emission and 6 cm and 20 cm continuum, Herschel PACS and SPIRE broadband data, and simulations fitting over 30 features. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2016-10-25T00:58:07.000 |
| 1280 | 2024.1.00901.S | 0 | Precise Determination of N/O in a Luminous Lyman Break Galaxy at z=7.13 | The nitrogen-to-oxygen (N/O) abundance ratio is an important tracer of chemical evolution of galaxies. JWST observations show that GN-z11 at z = 10.6 and some high-redshift galaxies exhibit strong NIII] and NIV] emission lines, indicating log N/O > -0.4, which is >2.5 times as high as the solar value. The physical scenarios to explain this nitrogen enrichment are still under debate. A1689-zD1, gravitationally-lensed and apparently bright Lyman break galaxy at z = 7.13, is another excellent laboratory of the nitrogen enrichment, because previous observations suggested that this galaxy also has solar N/O abundance ratio from a tentative [NII] 122 um detection. We propose [NIII] 57 um emission line observations of A1689-zD1. Our science goal is to firmly establish the N/O abundance ratio by combining [NIII] 57 um and archival [OIII] 88 um and 52 um fluxes, free from uncertainty caused by ionization parameters. If A1689-zD1 has the N/O abundance ratio higher than the solar value, [NIII] 57 um emission line will be significantly detected. In the case of non-detection, the N/O abundance ratio is constrained to be log N/O < -1, which will be consistent with local star-forming galaxies. | Lyman Break Galaxies (LBG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1281 | 2018.A.00065.T | 29 | Molecular gas in the immediate vicinity of GRB 190829A, within a massive dusty galaxy | GRB190829A, detected on 29-August-2019 at z=0.079, is one of the closest GRBs ever discovered. However, unlike all other identified GRBs at z<1, GRB190829A is located in the metal-rich ISM of a massive galaxy, with its spectral properties indicating an over-dense environment, consistent with the hypothesis that GRBs form in regions with high star formation density. The GRB afterglow has been detected at 90 GHz with a flux density of 6.3 mJy. This provides the exciting opportunity to probe the molecular gas, the fuel for star formation, in the immediate vicinity of the GRB, by carrying out a search for CO and HCO^+ absorption. We propose here to use the ALMA Band-6 receivers to search for redshifted CO(J=2-1) and HCO^+(J=3-2) absorption against the GRB afterglow, to trace the conditions that resulted in the formation of the GRB. The time criticality of this proposal is because the observations have to be done within the next few days, while the mm-wave flux density of the GRB afterglow is sufficiently high for the proposed absorption spectroscopy. We request a total of 3.2 hours with the Band-6 receivers, including all overheads and calibration. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-03-17T12:26:16.000 |
| 1282 | 2013.1.00532.S | 18 | The Dense Gas Fraction and Its Dependence on Galactic Environment | In order to formulate a general star formation theory, the underlying physics that govern star formation processes within galaxies must be understood. Our recent results on extragalactic Giant Molecular Cloud (GMC) populations imply that the internal structure and organization of molecular gas strongly depends on galactic environment - as does their star formation efficiency (SFE), though with different dependencies. Recent studies suggest that the SFE is set by the dense gas fraction and not the global molecular reservoir. Thus, we propose to map the dense gas fraction of massive GMCs (at 70pc(=2") resolution) in the nearby spiral galaxy M74 with ALMA. The dense gas fraction will be determined using several 3mm tracers (low to high density: 12CO, CS, HCO+, 13CO, C18O, HCN, HNC). These tracers will additionally probe the excitation conditions (HCO+, HNC, HCN, 12CO) and independently estimate the CO-to-H2 conversion factor (via the (1-0) transitions of 12CO, 13CO, C18O plus 12CO(2-1)). The requested observations will cover the same area as already mapped in CO(2-1) by our Cycle 1 program that will characterize the general GMC population and the different galactic environments. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2016-03-02T14:20:58.000 |
| 1283 | 2017.1.00889.S | 139 | The feedback effect from massive stars on the fragmentation of dense structures | The relative importance of the mechanisms that shape the internal structure of the star forming clouds is one of the most important questions in the star formation community. The extraordinary capabilities offered by ALMA will allow us to obtain detailed map of the dense gas down to size scales ~0.02 pc, adequate to resolve the structures associated to dense cores and complex filamentary structures. We propose to observe the dense gas at 1 mm over the two different regions located in the Carina Nebula already observed at 3 mm with ALMA Cycle 4. We will use these maps to investigate the role that external pressure plays on determining the densest components inside the diffuse medium in these clouds. The stability status of the identified structures will be used to assess whether these are supported by external pressure, and at which scale the gravity becomes the dominant force. Detailed comparison of the distribution of the dense gas and the location of young stellar objects will shed light on the dependence of the star-formation threshold on the external pressure in these clouds with different level of impact of stellar feedback. | High-mass star formation | ISM and star formation | 2020-03-10T00:00:00.000 |
| 1284 | 2019.1.00597.S | 10 | Cold gas on the red sequence: resolving maintenance-mode feedback in action | We have recently discovered a new class of quiescent, relatively common early-type galaxy that hosts large-scale, AGN-driven winds (Cheung et al., 2016, Roy et al, 2018). This discovery is exciting because these red geysers- found in ~10% of the quiescent population- may be the missing energy source needed to maintain galaxies quiescent at late times. As initially revealed in integral field observations from the MaNGA survey (Bundy et al., 2015), red geysers feature characteristic ionized gas velocity fields that are roughly co-aligned with bisymmetric features of enhanced line emission that we believe trace the wind axis. The mass of gas is the ionized phase is small, but most of the mass is expected to be in the cold gas component. We propose to map two prototypical red geysers in CO(1-0) to obtain information about the amount of molecular gas associated with the outflow, its kinematics and mass outflow rate. These observations would therefore represent one of the most direct tests of the effect of maintenance-mode AGN feedback on its galaxy host. | Outflows, jets, feedback | Active galaxies | 2021-04-13T12:55:58.000 |
| 1285 | 2017.1.01687.S | 65 | Characterizing the solar nebula analog MP Mus | The number of nearby, primordial circumstellar disks is very small, which significantly limits our current understanding of their evolution. We propose to observe the evolved disk around the nearby (100 pc) solar analog MP Mus, a source very similar to the famous TW Hya disk that is still mostly unexplored. Despite its age (8-15 Myr), MP Mus is surrounded by a gas and dust rich disk that may have a large cavity, as suggested by its SED and previous coronagraphic observations. We propose to perform a comprehensive characterization of this target with spatially resolved observations of its dust continuum emission at bands 7 and 4, together with 12CO(3-2) and 13CO(3-2) observations. These data will: 1) reveal the dust distribution of the disk around MP Mus and unambiguously identify the presence of a cavity, 2) probe dust growth and migration at different locations in the disk, 3) determine the gas distribution and mass, and 4) accurately estimate its gas-to-dust ratio. The proximity, age, and characteristics of MP Mus make it a perfect laboratory to better understand disk evolution and planet formation. | Disks around low-mass stars | Disks and planet formation | 2019-07-26T21:14:02.000 |
| 1286 | 2021.A.00023.S | 40 | A Pilot Study for the Far-IR Confirmation of the Oldest Galaxies Observed by JWST | We propose ALMA observation of the recently discovered galaxy candidate, GLz11 at z=10.74, from the JWST ERS program. JWST will routinely discover these early galaxies and can do a census of similar z>10 galaxies to understand the first galaxy formation. ALMA is the only instrument with the sensitivity to detect the FIR continuum and fine structure from such an object, and has a strong synergy with the JWST observation to study the high-redshift galaxy formation. The observation of FIR SED including cooling line is very important to measure the spectroscopic redshift and constrain the physical parameters from SED modeling in terms of constraining dust content to break the age-dust degeneracy. Our program will observe the FIR peak of GLz11 with spectral window set up covered by 3 Science Goals such that 88.63micron [OIII] emission line is included in the sufficient redshift range (z=10.30-11.21) for spectroscopic redshift confirmation. The proposed observation has the very real potential to both verify a key science program for the JWST by confirming an extreme redshift galaxy, and demonstrate the importance of ALMA in the JWST era for studying the first galaxies in the Universe. | Galaxy structure & evolution | Galaxy evolution | 2022-09-22T18:32:16.000 |
| 1287 | 2023.1.00114.S | 0 | A complete census of dust in sub-millimeter galaxies | The ALMA Cycle 0 follow-up of sub-mm sources in the ECDF-South at 345 GHz (Band7) pinpointed the locations of sub-millimeter galaxies (SMGs), and build the first statistically reliable sample of SMGs, ALESS, which contains 99 SMGs at a median redshift of 2.7. A high-priority Cycle 3 project set out to complete the characterization of the IR/sub-mm SEDs of the ALESS SMGs by obtaining their total continuum fluxes at 682GHz (Band 9) and 150GHz (Band 4). These observations, combined with existing continuum fluxes in Band 7, are crucial to fully characterize the amount and physical properties of dust in these SMGs. By measuring near the peak of the dust emission (Band 9), and in the Rayleigh-Jeans regime (Band 4), we will constrain the dust masses of our galaxies at least 5 times more precisely than possible with current observations. So far the Band 4 data were delivered, but the Band 9 component remains unobserved after being on the observing queue for several cycles. This proposal aims to obtain the missing Band 9 observations, which are essential to break physical degeneracies and will allow us to investigate the dust properties and heating in SMGs, and their mode of star formation. | Sub-mm Galaxies (SMG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1288 | 2013.1.01213.S | 21 | Testing the reversal of the star-formation-density relation in a high redshift cluster | We propose to measure the continnium and CO line fluxes for the star-forming galaxies at the center of cluster XCSJ2215 at z=1.46. The four first priority sources within 0.25Mpc radius of the cluster are detected in the SCUBA-2 850um image, and their counterparts in Spitzer IRAC and/or MIPS 24um images are confirmed cluster members. We attempt to examine the dynamics, the molecular gas mass, the star formation efficiency, and the dust to gas ratio of these cluster galaxies from the CO(2-1) line observation. In addition, the continnum observation at band 6 is required to solve the multiplicity issue, and to detect less star-forming galaxies indicated from the [OII] emissions. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2016-11-18T17:57:04.000 |
| 1289 | 2019.1.01118.S | 54 | The Molecular Exosphere of Ceres: Pinpointing Its Surface Origins | Observations of water ice and hazes on Ceres by Dawn Space Mission point to the existence of an exosphere. Based on existing ALMA data, we establish the presence of Ceres exosphere. To reveal the true nature of the molecular exosphere, we propose high resolution observations to resolve Ceres disk spatially so to locate the surface origins of Ceres exosphere. Our ultimate goal is to: 1) pinpoint exact locations of solar sputtering and/or outgassing plumes; 2) associate the exospheric molecular species with surface features hence compositions to better understand ice chemistry; 3) distinguish molecular excitation mechanisms; 4) identify potentially plume-launching subsurface sites of reservoirs enriched in water ice; and 5) ascertain the viability of Ceres cometary origin via accretion or formation at great heliocentric distance. | Solar system - Planetary atmospheres | Solar system | 2022-08-18T20:50:01.000 |
| 1290 | 2019.2.00135.S | 88 | The effect of the massive stellar feedback across the Carina Nebula Complex | We have successfully completed an ALMA campaign in Cycle 4, 5 and 6 to study the location, mass distribution, and kinematics of the small-scale fragments within massive star-forming clumps in two regions with very different physical conditions, the Southern Pillars (SP) and the Northern Cloud (NC). We propose to expand this successfully observational campaign towards 10 regions in the Carina Nebula Complex using the ACA 7m in Band 3. This represents, to our best knowledge, the first survey of clumps at high resolution conducted in this extreme region of massive star formation. Detailed comparison of the distribution of the dense gas and the location of young stellar objects will shed light on the dependence of the star-formation threshold on the level of turbulence and external pressure in these clouds with different level of impact of stellar feedback. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-11-18T16:50:56.000 |
| 1291 | 2022.1.01058.S | 5 | Reveal the 10~au scale substructures in two protostellar disks | Small-scale substructures, including spiral arms and misaligned/warped inner disk, have been found in circumstellar disks around low-mass protostars when they are still in a disk forming phase (Class 0/I). To study these substructures is important for our understanding of star/planet formation and origin of multiplicity. Within the intermediate mass star forming region NGC2071IR, we have identified two sources (IRS1, IRS3) with strong evidence of disk substructures at a few 10AU scale. IRS1 is an intermediate mass protostellar system (3Msun | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2024-09-08T12:27:28.000 |
| 1292 | 2021.1.00378.S | 627 | Size distributions and multi-frequency characterization of 100 disks in Ophiuchus | This proposal is designed to make significant progress in two important areas in disk demographics: continuum disk sizes and multi-frequency characterization. Disk sizes set the basic architectures of planetary systems. However, even after many years of ALMA operations, the size distribution of protoplanetary disks in nearby star-forming regions still remains to be established. Similarly, while unresolved observations at single frequencies allow for interesting studies of disk mass as a function of stellar mass, cluster age, multiplicity, and SED Class, such studies require strong assumptions regarding optical depths, dust temperatures, and grain size distributions. Testing these assumptions and their dependence on disk properties requires the analysis of multi-frequency data. Here we propose a very efficient Band-4 and Band-8 program that, thanks to the use of archival data, will result in an unprecedented data set to enable demographic studies: 40 bright disks resolved at 0.2 resolution in 4 bands (Band-4, 6, 7, and 8), Band-8 disk sizes and Integrated spectral indices (between Band-4, 6, and 8) for 60 additional objects, and Band-8 continuum disk sizes for 100 objects. | Disks around low-mass stars | Disks and planet formation | 2023-09-01T12:26:41.000 |
| 1293 | 2015.1.00007.S | 37 | Not alone?: Solving the complex mass loss puzzle of U Ant | We propose to observe the circumstellar environment of the carbon AGB U Ant in the CO(1-0) and CO(2-1) transitions. We will constrain the recent mass-loss history, the connection between thermal pulses and the large detached shell of dust and gas, and the nature of small scale structure within the detached shell. The interpretation of observations of detached-shell sources are often limited by low angular resolution or the lack of velocity information. The observations proposed here will have a spectral resolution of 0.6 km/s and an angular resolution of 1.5". They will spatially resolve the detached shell and the morphology of the mass loss. The spectral resolution will allow us to determine the dynamical structure of the gas. Using 3-D radiative transfer models, we will constrain the mass and temperature of the gas. Combined with hydrodynamical models we will be able to determine the mass-loss history of the star, constrain the interaction between the dust and the gas, and the influence of a suspected binary companion on the wind. The observations will in detail describe the process that is responsible for the chemical evolution of the star and the ISM. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2017-06-17T10:50:36.000 |
| 1294 | 2019.1.00964.S | 163 | Towards improved constraints on dark matter with strongly lensed quasars | Gravitationally lensed quasars have been established as a method to detect and quantify low-mass dark matter haloes at cosmological distances. The population of low-mass haloes is dependent on the mass of the dark matter particle, thus investigations of these lenses can give independent constraints on warm dark matter. We have an ongoing a programme to make competitive inferences on the halo mass function with short observations of lensed quasars with ALMA. Here, we ask for 'snapshot' observations to identify new lens systems suitable for high-resolution follow-up in our programme. We estimate that we will detect at least 12 of these systems based on a previous large survey. If most of these sample are suitable targets, we estimate that we can put a constaint on the thermal relic mass of warm dark matter that is significantly more stringent than the current limits from lensing and other inferences after high-resolution follow-up. As we require only snapshot observations of these targets at any angular resolutions >0.5 arcsec in band 6, our programme is suitable for filler time scheduling. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2021-01-17T15:41:25.000 |
| 1295 | 2019.1.00492.S | 1 | Weighing massive protostars with salts | Stars' masses decide their fates. The masses of forming high-mass stars are challenging to measure. The most direct and accurate method to measure a protostar's mass is by measuring the rotation curve of its orbiting disk. However, most high-mass stars are surrounded by a dust and molecule-rich medium that obscures the disk's kinematics. We recently discovered that several molecules, NaCl and KCl, uniquely trace the disk around high-mass protostars and are not present in the obscuring gas cores. We propose to observe a sample of high-mass protostars in these lines to kinematically measure their masses and demonstrate the viability of these lines as kinematic mass tracers. | High-mass star formation | ISM and star formation | 2022-12-04T18:25:24.000 |
| 1296 | 2023.1.01342.S | 126 | Investigating the cause of Low-Frequency Turnovers in the SEDs of SFGs: Constraining the Thermal Emission | The physical mechanisms which govern the radio emission and infrafred-radio correlation (IRRC) in star-forming galaxies (SFGs) are well known but poorly understood. Radio emission from SFGs is often modelled using simple two-component power laws including thermal free-free emission and non-thermal synchrotron emission. However, recent low-frequency observations from the MWA GLEAM survey have found some SFGs exhibit much more complexity in their spectral energy distributions (SEDs) including low-frequency turnovers and higher frequency kinks. These SED features are suggested to be primarily caused by free-free absorption in compact star-forming regions. A study of nearby SFGs including resolved analysis of their radio emission is therefore vital to being able to connect the physical mechanisms occuring within these galaxies to their SED features. With this understanding we will then be able to interpret the future data obtained by the SKA. We propose ALMA Band-1 and 3 observations to measure the thermal emission of a sample of 16 SFGs which includes low-frequency turnover galaxies and control galaxies to investigate the physical properties which cause differences in their SEDs. | Starbursts, star formation | Active galaxies | 2025-03-20T03:36:10.000 |
| 1297 | 2024.1.00646.S | 0 | Revealing the star-formation efficiency and accretion history in an isolated protostellar system | Protostellar outflows play a critical role in the star-formation process. They remove angular momentum and mass from the protostar+disk system, while injecting momentum and energy into the surrounding core, disrupting the core and limiting the efficiency of star formation. They provide a fossil record of the accretion history of a protostar, with full maps providing a complete history of accretion. We will fully map the outflows from the isolated low-mass wide-binary protostellar system BHR71 with the ACA with 6" resolution (1200 au) in CO (2-1) and its isotopologues, SiO (5-4), and selected outflow tracers to reveal their detailed structure and kinematics, and determine their fundamental properties (e.g., total mass & momentum). With this information on this isolated system we can examine the impact of the flows on the natal core, the role of feedback on the star-formation process, and the accretion history of the protostars, thus addressing key questions on the efficiency of star formation, and how protostars accrete. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1298 | 2016.1.00540.S | 49 | Unveiling the jet core and central stellar object of the "water fountain" source W43A | "Water fountain" sources exhibit collimated, fast bipolar jets from AGB/post-AGB stars traced by water masers. Here we propose imaging of molecular (thermal and maser) lines (including shock traces) and continuum emission toward the archetypical water fountain W43A. VLBI observations of H2O, SiO, and OH masers in W43A at milliarcsecond resolution have found bow-shock and point-symmetric clumpy structures in the jet, a biconical fast flow in the vicinity of the star, and a spherical and slow expansion of the circumstellar envelope. Together with these components, the decadal evolution of the H2O maser distribution and the bipolar morphology of the mid-infrared emission suggest that W43A has just entered the water fountain stage. Before the records of the jet and envelope evolution are lost by the photoionization by the central stellar object to form a planetary nebula, we wish to reveal the whole kinematic and physical structure of W43A in order to unvail the central stellar system. W43A is the most promising source for exploring the central system, i.e., a rotating torus or a binary system in the vicinity (~40 AU) of the central system through sub-mm SiO maser emission. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-10-18T01:13:16.000 |
| 1299 | 2016.1.01043.S | 40 | Determining the Physical State of Two Massive, Dynamically Ambiguous Galaxy Clusters | Galaxy clusters are vital probes of cosmology. Much progress has been made with the simple assumptions that they are relaxed and spherically symmetric, but high angular resolution X-ray observations from Chandra and XMM over the past decade and a half have revealed that clusters show a variety of deviations from this simple concept of equilibrium. More recently high angular resolution SZE observations have emerged as a powerful and complementary technique. In several cases high-resolution (~10") SZE observations have identified very hot, 100-kpc scale regions of very well studied clusters which had previously been missed by modern X-ray observations. It is important to observationally quantify the prevalance and character of these disturbances to have a complete & accurate picture of galaxy clusters. MUSTANG SZ observations of Abell 611 and MACSJ1206-0847 showed low- to medium-significance hints of 100-kpc scale hot gas. These clusters also showed a mix of other dynamical markers. We propose here to conclusively unveil & characterize these features with 5" - 10" resolution, targeted SZE imaging using ALMA Band 3. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2018-02-23T02:34:59.000 |
| 1300 | 2018.1.01660.S | 17 | Imaging possible self-gravitation effects in the disk around a high-mass protostar | Self-gravitation effects and disk fragmentation are expected to play a fundamental role in high-mass formation, both to enable high accretion rates and to produce the massive companions that are observed around high-mass stars. IRAS13481-6124 is a 20 solar mass high-mass protostar, whose inner disk structure has been studied extensively with our near- and mid-infrared interferometric observations. Our radiative transfer modeling and ATCA millimeter interferometry suggests that the disk mass is comparable to the mass of the central object. Intriguingly, in ALMA Cycle 5 observations we detected an spiral arm feature in the inner 300 AU around the object, whose morphology is similar to the ones seens in hydrodynamic simulations of self-gravitation disks. Here, we propose follow-up observations with 2.5-times high resolution and in a complementary frequency band that will allow us to characterise the physical conditions in the spiral arm and to resolve possible sub-structure, informing hydrodynamic simulations that will be conducted by the theory experts in our team. | Disks around high-mass stars | Disks and planet formation | 2020-10-29T15:39:56.000 |
| 1301 | 2022.A.00017.S | 15 | Support for JWST Observations of the Closest Solar Type Star alpha Centauri | We propose a single, 2 hr observation of alpha Centauri to improve the absolute astrometry of the star in support of an approved and scheduled program with the James Webb Space Telescope (JWST) to search for a planet orbiting our nearest solar type neighbor. | Main sequence stars | Stars and stellar evolution | 2023-12-08T21:33:04.000 |
| 1302 | 2013.1.00978.S | 1 | The Orcus-Vanth System: A Rosetta Stone for accretion in planetary systems | The dwarf planets in the Kuiper belt provide one of the most compelling cases of the breakdown of the simple theory of pairwise accretion. The formation of these large rock-rich dwa rf planets through coagulation of the population of small low density near rock-free objects appears difficult. Alternative accretion theories predict a wide variety of behaviors of the size-density relationship through the small body-large body transition. The Orcus-Vanth binary system is uniquely suited to determining the density behavior through this transition and pointing to the accretion hi story of the solar system. The new higher resolution capabilities of ALMA in Cycle 2 allow us, for the first time, to use resolved thermal radiometry to measure the individual component sizes and, the unique capability of highly accurate relative astrometry over moderate angles will let us determine the astrometric wobble of Orcus induced by Vanth to measure the individual component masses, yield ing simultaneous densities of two of these transitional objects and a chance to determine how solid bodies in planetary systems form. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2016-09-29T14:55:19.000 |
| 1303 | 2018.1.01536.S | 16 | Measuring magnetic fields of galaxies in the early Universe | Although the magnetic field of galaxies are expected to be generated already early in their existence, very few observations of magnetic fields at high redshifts exist. It has been suggested the polarisation observations of the CII fine structure line can provide a unique probe of ISM magnetic fields, both in our Galaxy and far beyond. Observing CII polarisation has so far been impossible because of the lack of instrumentation. However, in high-z sources, ALMA has shown it has the sensitivity to detect CII at high signal to noise. This opens up the possibility to directly observe high-z magnetic fields. Here we propose a proof of concept by studying CII in both a quasar host galaxy and a starburst galaxy in order to probe two different regimes in which CII polarisation can be generated. Should the observations, requiring only 6 hours of ALMA time, be successful, it will not only prove the use of fine structure lines in ISM magnetic field studies, but also open up a window to study magnetic fields all the way into the epoch of reionisation. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2020-08-06T01:32:05.000 |
| 1304 | 2013.1.00884.S | 77 | What impact do luminous AGN have on star formation? | One of the outstanding issues in the formation and evolution of galaxies is a definitive measurement of the impact that AGN have on Star Formation (SF). Observationally the picture is very mixed with conflicting results arguing for all scenarios: luminous AGNs suppressing, enhancing, or having no impact on SF! A major issue is the lack of sufficiently deep FIR-submm observations to directly measure the SF properties for the majority of the AGN population. The primary aim of this proposal is to build on our ALMA cycle 1 programme, combined with our carefully deblended Herschel photometry, to measure individual SFRs for a complete sample of X-ray selected AGN over the key X-ray luminosity and redshift ranges (L_X=10^43-10^45 erg/s and z=1.5-3.2), where the impact of AGNs on star formation is thought to be most prevalent. With the proposed observations we will construct detailed SFR distributions as a function of key AGN properties to accurately measure the impact that AGN have on SF in their host galaxies. Our observations will provide a key test for galaxy formation models which employ a wide variety of different prescriptions of AGN and SF activity. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2016-02-23T14:08:13.000 |
| 1305 | 2024.1.00790.S | 0 | A Deep CI Search for a Photoevaporative Wind in the IM Lup Disk | Sensitive, high frequency observations now possible with ALMA have enabled the detection of neutral atomic carbon (CI) in a handful of protoplanetary disks. Unlike most commonly-observed molecular tracers, CI provides a unique tracer of dynamical features in disks, such as localized planet-driven outflows, infalling streams, and photoevaporative winds. In fact, CI is predicted to show dramatic deviations from Keplerian rotation at large disk radii in the presence of disk winds. This makes CI the best, and perhaps only, tracer of outer disk winds readily accessible to ALMA. Here, we propose to observe the IM Lup disk, which shows compelling evidence of external photoevaporation, to provide the first unambiguous detection and characterization of a disk photoevaporative wind using deep, high-resolution [C I] 1-0 Band 8 observations. These observations will yield the strongest constraints on the nature of mass-loss in the outer regions of protoplanetary disks, which have significant implications for models of disk dynamics, structure, and evolution as well as the available mass reservoir needed to form planets. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 1306 | 2015.1.00534.S | 9 | Probing Planet-Forming Zones in Orion Nebula Cluster Disks | We propose to mosaic the central 1.5' x 1.5' of the Orion Nebular cluster (ONC) at 350 GHz with ALMA. With an angular resolution of 0.08'', we will resolve linear radii smaller than 25 AU in the circumstellar disks of ONC cluster members. Our mosaic will encompass >150 cluster members within a uniform sensitivity region where we can detect average disks at the 3sigma level. An additional ~50 objects in the outskirts of our field will be included at somewhat reduced sensitivity. Continuum observations of this sample will produce the deepest and most accurate disk mass distribution to date, and will constrain the planet-forming potential of a population of young stars in an environment that is typical of star formation in the Galaxy and also resembles our own Sun's birthplace. In addition, observations of CO and HCO+ will probe the disk gas content and allow us to measure stellar masses through disk dynamics. These lines will also allow us to study feedback processes at the scales of disks and evelopes. This program will resolve solar system scales in ONC disks, and constrain planet formation models directly for the first time in a clustered star forming region. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2018-04-13T01:18:02.000 |
| 1307 | 2015.1.00773.S | 56 | An ALMA Search for Disks around Planetary Mass Companions | In the last decade, direct imaging surveys have discovered dozens of planetary mass companions (PMCs) at ultra-wide separations from their host stars. The origin of these objects remains unclear, as canonical planet formation theories are not effective at such high radii. Recent studies, however, suggest that these enigmatic objects may be surrounded by disks of primordial material. Direct detection and characterization of these disks provides a new avenue for studying the formation of PMCs as well as their potential exomoon systems. Here we propose to survey 7 PMCs which show indirect evidence for the presence of such a disk. With ALMA we will image those disks and calculate disk masses to constrain PMC evolutionary paths as well as the amount of material available to form exomoons. We will also use 0.1" spatial resolution to resolve circumplanetary disks, measure their sizes and structures, search for CO (2-1) emission to measure Keplerian rotation and thereby dynamical masses for PMCs, and trace disk evolution by comparing disk morphology at different ages. This proposal is an important first step towards better understanding the formation of PMCs and exomoon systems. | Exo-planets | Disks and planet formation | 2017-01-25T22:32:32.000 |
| 1308 | 2021.1.00581.S | 28 | Radial Distributions of Sufur-Bearing Species in Disk Forming Regions | Sulfur-bearing species (S-species) are now spotlighted in astrochemistry and astrophysics. First, S-species such as H2CS and OCS are found to trace the protostellar and protoplanetary disks around Solar-type protostars. Second, they are detected in the Solar System comet, suggesting a possible link between the interstellar and planetary chemistry. Although chemical differentiation of S-species is recognized in disk-forming regions, it is not understood in terms of chemical processes. This is because the distributions of S-species, including H2S the major reservoir of S-atoms specifically, in disk-forming regions are still obscure. To overcome this situation, we here propose to delineate the radial distributions of fundamental S-species in Band 5 at a high angular resolution toward four young protostellar sources: IRAS 16293-2422, Serpens SMM 1/4, and B335. We also evaluate the temperature distribution in disk-forming regions by using the multiple lines of H2CS. The result will constitute a valuable template for studies on sulfur chemistry in protostellar sources. | Low-mass star formation, Astrochemistry | ISM and star formation | 2024-06-01T23:00:17.000 |
| 1309 | 2016.1.00333.S | 31 | [OIII] observations towards the z=6.027, gravitationally lensed galaxy A383-5.1 | We have discovered redshifted [CII] in the z=6.027 star-forming A383-5.1. It is the so-far faintest and only [CII] detection at z>6 in a normal star-forming galaxy. A383-5.1 has a star-formation rate of 3.2 Msun/yr, similar to that of the Milky Way, low metallicity (log(Z/Zsun) = -1.33), and is gravitationally lensed by a factor 11.4. We propose to do Cycle-4 ALMA observations of the [OIII] 88um emission line in order to characterise the physical conditions of the ISM in A383-5.1. With very few [CII] detections in other z>6 galaxies, it is difficult to make predictions for the far-infrared fine-structure lines for other galaxies, however, with the [CII] detection in hand and the fact that A383-5.1 has a low metallicity as well low dust content, it is an ideal candidate to search for the expected bright [OIII] 88um line. Generally, FIR fine-structure line observations in the early universe is still an unchartered topic with very few detections, hence a detection of [OIII] would provide valuable insights into the physical conditions of early galaxy evolution. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2019-10-19T19:54:20.000 |
| 1310 | 2018.1.00681.S | 124 | Unveiling molecular gas contents within normal star-forming galaxies at z~3.3 | Star-forming galaxies at z=3-4 are expected to be in a phase of an accelerated growth towards z~2, which requires a gas inflow from the outside. Such a prominent gas inflow is also suggested from the observational results that star-forming galaxies at z>3 do not follow the same stellar mass-SFR-gas metallicity relation as galaxies at z=0-2. At z > 3, the cosmological gas inflow is likely to be dominant and hence cause the dilution of gas metallicity. In order to investigate how the inflow/outflow processes are involved in the star formation activities and interstellar medium conditions of young galaxies at z>3, it is essential to measure the molecular gas contents of these galaxies. We propose dust continuum observations at Band-6 of 12 star-forming galaxies at z~3.3, for which we have already measured gas metallicities from the Keck/MOSFIRE spectra. We estimate molecular gas masses from the dust continuum and derive gas mass fractions and star formation efficiencies by taking into account the gas metallicities. Moreover, by combining the gas metallicities, SFRs and gas mass fractions with chemical evolution models, we will constrain the inflow/outflow rates of galaxies at z~3.3. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-01-09T22:36:19.000 |
| 1311 | 2012.1.00178.S | 3 | Deuterated Ammonia in Prestellar Cores | Stars form in molecular cloud cores, cold and dense regions enshrouded by dust. The initiation of this process is among the least understood steps of star formation. High-resolution heterodyne spectroscopy provides invaluable information about the physical conditions (density, temperature), kinematics (infall, outflows), and chemistry of these regions. Classical molecular tracers, such CO, CS, and many other abundant gas-phase species, have been shown to freeze out onto dust grain mantles in prestellar cores. However, N-bearing species, in particular ammonia, are much less affected by depletion and are observed to stay in the gas phase at densities in excess of 106 cm-3. The molecular freeze-out has important consequences for the chemistry of dense gas. In particular, the depletion of abundant gas-phase species with heavy atoms drives up abundances of deuterated H3+ isotopologues, which in turn results in spectacular deuteration levels of molecules that do remain in the gas phase. Consequently, lines of deuterated N-bearing species, in particular the fundamental lines of ammonia isotopologues, having very high critical densities, are optimum tracers of innermost regions of dense cores. We propose to study the morphology, density structure and kinematics of a prototypical dense cloud core, by mapping the spatial distribution of ammonia isotopologues in L1689N using ALMA in its most compact configuration. These observations provide optimum probes of the onset of star formation, as well as the physical processes that control gas-grain interaction, freeze-out, mantle ejection and deuteration. The sensitive, high-resolution spectra acquired within this program will be analyzed using sophisticated radiative transfer models and compared with outputs of state-of-the-art 3D MHD simulations and chemical models developed by the members of our team. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2021-03-12T00:00:00.000 |
| 1312 | 2019.1.00567.S | 8 | Directly measuring the progression of infall from the envelope to the disk-forming region of BHR 71 | Infall transforms dense cores into protostars. During the embedded phase of star formation, the evolution of infall determines the final mass of the central protostar as well as the initial condition of the disk and planet formation. Theoretical studies still debate about the types of infall, the "inside-out" or "outside-in" fashions, and the effects of rotation and magnetic fields; only few direct observation of infall exists to constrain the infall process. Previously, we have detected an unambiguous signature of infall, toward an embedded protostar, BHR 71, and modeled the infall kinematics. To trace the progression of infall, we propose here to measure the radial variation of infall toward BHR 71 via multiple transitions of HCO+, empirically probing the infall at different radii, and the resolved emission of complex organic molecules (COMs), tracing the kinematics close to the disk. We will trace the kinematics from the envelope (~1000 au) to the disk-forming region (~30 au), identifying the type of infall and probing the transition from infall to rotation. Furthermore, we will survey the high frequency emission of COMs to complement the previous discovery of COMs. | Low-mass star formation | ISM and star formation | 2022-08-12T23:07:00.000 |
| 1313 | 2012.1.00423.S | 0 | The evolution of the molecular gas content at z>3 | Revealing the origin of the enhanced cosmic star formation rate density at high redshifts is fundamental for understanding galaxy evolution, because it is responsible for producing the bulk of stars observed locally. Recent observations and theoretical studies have suggested that the evolution of the cosmic star-formation rate is not regulated by variations of the star-formation efficiency (due to merger/interaction processes), but by the evolution of the content of molecular gas in galaxies. This can be examined observationally, and actually galaxies at z~2 show much higher gas fraction than local galaxies, in agreement with theoretical expectations. At z>3 the situation remains uncertain. The few CO measurements of submillimeter galaxies (SMGs) and extremely bright Lyman-break galaxies (LBGs) at z~3 available today indicate lower gas fractions (20-50%) than predicted. However, those galaxies with SFRs up to ~1000 Msun/yr are not representative of the bulk of star-forming galaxies at z~3. Moreover, their metallicities remain poorly constrained, hence the CO-to-H2 conversion is highly uncertain. Here we propose to measure the gas fractions of four `normal' galaxies at z~3.0-3.5 through ALMA band 3 observations of CO emission. We focus on four LBGs investigated in the AMAZE project (an ESO Large Program; Maiolino, Nagao, et al. 2008), which is based on near-infrared integral field observations with VLT/SINFONI. The selected galaxies are optimal targets for achieving our scientific goal because they are representative of the usual, UV-selected LBG population, contributing to the bulk of the star formation activity at those redshifts. Also, these galaxies are very well studied, and their properties such as metallicity (which allows for direct inference of the critical CO/H2 conversion factor), stellar mass, morphology, and dynamics are well determined from a large collection of data, including SINFONI spatially-resolved near-IR spectroscopy, HST optical and near-IR imaging, and Spitzer mid-IR photometry. The obtained gas content information of the targets will enable us, for the first time, to identify the dominant mode of star formation at z>3. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2015-01-23T01:19:00.000 |
| 1314 | 2015.1.01056.S | 40 | ALMA Mapping of a Great Case of Ongoing Ram Pressure Stripping in the Nearby Virgo Cluster | We propose to map CO(2-1), CO(3-2) and 870um continuum in the spiral NGC~4402, one of the best cases of active ram pressure stripping in the nearby Virgo cluster. HST images reveal a remarkable variety of ISM features associated with ongoing stripping that we would like to characterize, including kpc-scale head-tail filaments, small decoupled clouds, ablated extraplanar dust plumes, several-kpc-long extraplanar dust fronts, and leading edge star-forming complexes. We will measure cloud sizes, linewidths, masses (gas and dust), and CO(3-2)/CO(2-1) ratios, and compare cloud properties with various nearby galaxies, to learn whether the clouds which appear to be affected by ram pressure have distinct properties. We can determine the cloud mass function and its spatial variation, to explore whether ISM compression along the leading edge results in more massive clouds, and estimate the fraction of the ISM mass that decouples during stripping. Comparison of simulations with these detailed observations of gas being stripped from the disk will give us a better understanding of the efficiency of stripping, and therefore its impact as a quenching mechanism throughout the universe. | Spiral galaxies, Galaxy groups and clusters | Local Universe | 2017-09-28T21:49:54.000 |
| 1315 | 2016.1.00585.S | 13 | Giant factory caught contaminating the environment: dust and molecules expelled by eta Carinae | Eta Carinae is one of the most massive stellar sources in the Milky Way; it entered the hall of fame of astronomy in the mid 19th century when it underwent a major outburst known as the Great Eruption. This event led to the ejection of at least ten Solar masses of material, now distributed in a bipolar nebula called the Homunculus. The material in the Homunculus is nitrogen-rich and carbon- and oxygen-poor, as expected for stellar matter after an interrupted CNO cycle: it provides us with a rare example of an ejecta that has not yet mixed with the ambient medium. Dust and molecules have formed out of this material, and recent APEX and Herschel observations have shown that the chemical composition of the molecular component reflects the peculiar elemental abundances of the Homunculus. Here, we propose to constrain the spatial distribution of the dust and molecular components using high resolution ALMA observations. These observations will constitute a fundamental step toward a complete understanding of the origin and the dust and molecular component around eta Carinae, that will have important repercussions for our comprehension of the latest stages of massive stellar evolution. | Luminous Blue Variables (LBV) | Stars and stellar evolution | 2018-02-02T08:22:05.000 |
| 1316 | 2017.1.01729.S | 87 | Monitoring radio emission of the youngest planetary system with ALMA | Millimeter or submm emission has never been detected from exoplanets or their hosts up to date. The recently discovered hot Jupiter V830 Tau b orbiting a weak-line TT star with a strong magnetic field is a promising system for a first detection in submm wavelength. The system has been detected twice in centimeter by VLA and VLBA among 5 observations, and thus the system is highly variable in radio emission. It is unclear why it varies, and whether it emits from the star, the planet or an interaction between them. We propose to observe the system 5 times in Band 3 with uneven intervals in about 20 days, and a single observation in Band 6 with ALMA, both aiming to reach a sensivitiy of 18uJy. The detection or the non-detection will firstly give us crucial constrainst on the origin of radio emission, and will help to understand the varibility of radio emissions. A first detection of mm-wavelength emission will open a new window for the study of exoplanets, and provide important information about magnetic fields, and therefore planets' interior structure, habitability and atmospheric retention. | Exo-planets | Disks and planet formation | 2019-01-23T04:02:43.000 |
| 1317 | 2012.1.00988.S | 0 | The Cold Phase of a Hot Mode: Filaments and Feedback in Abell 2597 | We propose an ALMA Band 6 observation of the central brightest cluster galaxy (BCG) in the rapidly cooling galaxy cluster Abell 2597 ($z=0.082$). Our goal is to obtain a spatially resolved map of cold gas structure and dynamics amid optical and X-ray cooling flow filaments, an arc of possibly jet-triggered star formation, and an AGN-driven multiphase (10^3-10^7 K) outflow. In a single pointing, ALMA can advance our understanding of the mysterious cold phase associated with these phenomena, each of which is a unique signature of unsolved problems relevant to galaxy evolution models at both early and late epochs. Our proposed CO(2-1) and mm continuum observation will test hot vs.cold accretion origins for the kpc-scale gas filaments in A2597, as well as the poorly understood mechanical interaction between a propagating radio source and its ambient cold molecular medium. ALMA is the only facility capable of discovering a spatially resolved AGN jet-driven molecular gas outflow in A2597, which we believe is likely given recently published multiwavelength evidence. Cold outflows in cool core galaxy clusters are an important and emergent focus of study that is largely enabled by ALMA's sensitivity and spatial resolution. This target is therefore ideal for Early Science, and would be an efficient demonstration of ALMA's breakthrough capabilities in a field with broad implications for galaxy evolution. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2014-12-13T14:28:00.000 |
| 1318 | 2013.1.00489.S | 10 | Are there disks around O-type protostars? | Our objective is to establish whether circumstellar disks exist around O-type (proto)stars, and to characterize them. This is crucial because theory predicts that disk-outflow systems can solve the "radiation-pressure problem" and explain the formation of stars up to 140 Mo. In a Cycle 0 proposal, we found 2 Keplerian disks around young B-type stars. The success of our experiment indicates that disk accretion is the formation route of stars up to 20 Mo. We now wish to extend our search to the most massive stars. We have selected the 6 best possible targets based on the luminosity, IR colour, distance, and association with hot-core tracers and outflows. We wish to observe known disk tracers such as CH3CN in the C34-7 configuration in band 6, to attain about 0.2" resolution, sufficient to resolve disks whose size is predicted to be >0.5". We will interpret the data by means of numerical simulations already available to us. We stress that our project will be successful even if no disk should be detected, because we will set a tight upper limit on the disk diameter and prove that disk-mediated accretion in O-type stars is not as effective as in lower-mass stars. | High-mass star formation | ISM and star formation | 2016-09-24T17:32:10.000 |
| 1319 | 2012.1.00678.S | 7 | Sculpting Round Circumstellar Envelopes into Bipolar Nebulae: A CO J=3-2 study of the Water-Fountain Nebula IRAS16342-3814 | We propose to map the jet outflow in the bipolar pre-planetary nebulaIRAS16342-3814 in the CO J=3-2 line with 0.22 arcsec resolution. Planetarynebulae (PNe) show a dazzling variety of elliptical, bipolar and multipolarmorphologies, and hydrodynamic sculpting of the progenitor AGB star'sspherically-symmetric circumstellar envelope by wandering and/or episodic jetsfrom the inside-out is one of the most promising mechanisms for shaping PNe. Theproposed study of IRAS16342-3814, the most prominent member of a class of youngPPNs called "water-fountain" nebulae in which the jet activity is extremelyrecent, will enable a significant advance in quantitatively understanding thejet-sculpting process. High-resolution HST and Adaptive Optics images ofIRAS16342-3814 and VLA/VLBA interferometry indicate nebular shaping inaction in this object. ALMA mapping of the CO line emission in IRAS16342-3814,which will enable us to determine the temperature and mass of acceleratedmaterial as a function of radius, latitudinal angle and velocity, is now neededto understand the jet dynamics and build quantitative models of jet-shaping.Our observations will also directly detect, for the first time, material inthe dark, dusty waist separating the bipolar lobes, enabling us to determine its mass and kinematics, and thus constrain its origin, which is currentlyunknown. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2016-10-16T02:38:40.000 |
| 1320 | 2016.1.00176.S | 1 | NGC 1068: a torus created by a magnetic wind | ALMA Band 6 has resolved, ~10 pc diameter, the torus of NGC 1068, whose morphology and kinematics suggest to be the signature of a magneto-hydrodynamical (MHD) instability. Our subarcsecond infrared polarimetric observations have shown that the polarization from the inner edge, ~0.4 pc, of its torus is dominated by magnetically aligned dust grains in an wind. These studies suggest that the origin, evolution and morphology of the torus can be explained as a MHD wind. However, a convincing demonstration that large-scale magnetic fields are present in the torus is required to confirm/reject the MHD wind. We propose to obtain a polarized continuum flux image of the dusty torus of NGC 1068 using ALMA Band 7 at a spatial resolution of 0.05" (3.4 pc). As polarimetry is a vector quantity, this spatial resolution is crucial to resolve and enhance the contrast of the torus from other (un-)polarized components. The proposed Band 7 data and our infrared polarimetric observations, will enable us to construct the finest and broadest nuclear polarized SED of NGC 1068, that in combination with our own polarization models, will allow us to physically constraint the MHD wind. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-11-30T21:40:15.000 |
| 1321 | 2016.2.00027.S | 4 | Complex organic molecules in UV irradiated gas: The Horsehead PDR | Despite the observational efforts we are still far from understanding how chemical complexity increases in space. In order to answer this question it is crucial to benchmark models with sources that have simple geometries, known physical conditions, and where the different grain surface and desorption processes can be isolated. The relatively low UV-illumination (thus cold grains) Horsehead photodissociation region (PDR) offers a unique laboratory to study the formation of complex organic molecules (COMs) because contrary to protostars, ice mantles can only desorb non-thermally. We know that photo-desorption is an efficient mechanism to release COMs from the ices, and that there is an efficient top-down chemistry operating, leading to enhanced charbon chains and COM abundances in this PDR. However, the relative contribution of the different photo-processes remains poorly constrained, and the dominant formation pathways of some species, particularly CH3CN and CH3NC, are unknown. We propose to use the ACA to image the emission of 7 COMs in the Horsehead PDR to investigate their dominant formation pathways and characterize the role of FUV photons in their formation. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2019-03-09T20:05:19.000 |
| 1322 | 2012.1.00523.S | 5 | Measuring the Infrared Emission and Dynamics for a Population of Primordial Galaxies | We propose to observe the dust continuum and CII line emission for an ultraviolet flux limited sample of 10 spectroscopically confirmed L>L_* "normal" galaxies at 55 from Keck and VLT along with the wealth of multi-wavelength data in the proposed COSMOS field ensure the physical properties and local environment of these sources is known. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2015-04-01T12:45:08.000 |
| 1323 | 2018.1.00548.S | 18 | A Dusty Starburst Galaxy Caught in a Heavy Bombardment? | The circumgalactic medium (CGM) is the battlefield between gas inflows along cosmic filaments and outflows from galactic disks. How the CGM connects to star formation is one of the most pressing questions in galaxy evolution. Although intervening cool gas in the CGM leads to strong Ly-a absorption that is evident in the spectra of background QSOs, there are only a handful of detections of the galaxies that give rise to strong absorbers at z > 2. By providing sensitive spectral mapping, ALMA is revolutionizing this field. In Cycle 3, we identified the first association between a hyperluminous starburst galaxy and multiple strong HI absorbers at z ~ 2.7. The spectra of two background QSOs show consecutive Ly-a absorption spanning over 1700 km/s, indicating the existence of a 6-Mpc gas-rich overdensity. We propose deep band-3 observations to map out its spatial and kinematic structure in CO(3-2). By comparing the data with simulations, we will identify gas-rich subhalos of the starburst and check how long their bombardment could sustain the starburst. The observations will also shed light on the chemical enrichment of the CGM and the diverse gaseous environments in massive halos. | Sub-mm Galaxies (SMG), Damped Lyman Alpha (DLA) systems | Galaxy evolution | 2020-01-17T02:26:56.000 |
| 1324 | 2012.1.00001.S | 6 | The Molecular Medium in the Prototypical Barred Spiral NGC 1097 | The goal of this proposal is to spatially resolve and map all the various dynamically distinct environments of a bar in the prototypical barred spiral NGC 1097 using the most common molecular gas tracers at 3mm. Our aim is to better understand the molecular gas distribution and kinematics in relation to the star formation activity, bar-induced gas inflow and accretion. Specifically we want to better understand how the star formation progresses in the bar. The two possible hypothesis that can explain the observed location of HII regions on the leading side of the bar dust lane are that either the star formation is dominated by a dense phase in the bar not reflected in the 12CO emission which is better described by a diffuse phase, or star formation occurs in spurs on the trailing side of the bar. The observations proposed here will map the full bar in 12CO and half of the bar in the other common 3mm tracers (HCN, HCO+, 13CO) to determine the phase of the molecular gas along and across the bar dust lane. We will also study the spurs and determine how the density and kinematics (or local shear) controls the star formation activity. We will compare this to the bar end and the circumnuclear and inner rings. We will also use the high resolution an sensitivity data to constrain the gas inflow and accretion rates by directly comparing the observed kinematics to hydrodynamic and N-body simulations. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2016-11-08T02:13:50.000 |
| 1325 | 2019.1.00407.S | 33 | Connecting molecular gas properties of high-redshift galaxies observed in absorption and emission | Detailed information about the neutral and molecular gas-phase of the diffuse interstellar medium (ISM) in high-redshift star-forming galaxies can be obtained from absorption studies of gamma-ray burst (GRB) absorbers. Here we propose an ALMA survey for CO emission in a sample of high-redshift GRB host galaxies, which have been specifically selected based on the presence of strong H_2 absorption. We propose to use the Band-3 receiver to target the CO(3-2) emission line from this pilot sample of three GRB host galaxies at z~2-3. Our objectives with this proposal are 1) to search for molecular emission features from a sample of the strongest H_2-selected GRB host galaxy absorption systems, 2) to derive molecular gas masses from the CO line emission, and 3) to connect the molecular gas properties of these particular absorbers observed in absorption and emission. This pilot survey is the first step to establish a link between the detailed information obtained from absorption-line studies of the molecular gas in galaxies at the peak of cosmic star formation to that inferred from emission. | Damped Lyman Alpha (DLA) systems, Gamma Ray Bursts (GRB) | Cosmology | 2021-04-20T10:57:14.000 |
| 1326 | 2016.1.00593.S | 43 | Hot water from the inner 25AUs of the Class I source SVS13-A | The origin of terrestrial water is still a source of intense debate. A key element to shed light on it, is how water evolves with time in proto-Sun analogues. Specifically, two aspects are crucial: (1) the amount of water in the planet formation region (~ tens of AU) and (2) its deuterium fractionation. While water has been imaged in a few low-mass Class 0 sources, only single-dish observations (e.g. Herschel) exist towards more evolved Class I to Class III sources, and no detection at all of HDO. Recently, we detected seven HDO lines with upper level energies up to 800 K towards the Class I source SVS13-A. A non-LTE analysis provides severe constraints on the gas emitting size (~0.2", i.e. 48 AU), temperature (150 K) and density (3 10^7 cm-3). No H2^18O emission has been detected and the lower limit to the HDO/H2O does not help to understand whether it decreases from Class 0 to Class I, as we recently found for CH3OH and H2CO on the same source. We propose here new ALMA high spatial resolution and high sensitivity observations of HDO and H2^18O towards SVS13-A with a twofold goal: reveal the structure of the gas of emitting the hot water, and estimate its deuterium fractionation. | Astrochemistry | ISM and star formation | 2018-12-08T21:20:28.000 |
| 1327 | 2019.1.01784.S | 675 | Knocking on the door of Large Lens Samples with ALMA | Gravitationally lensed sources offer a unique window onto the Universe, by amplifying the background source both in flux and in angular size, and by probing the intervening matter. This allows large samples of gravitational lenses to statistically measure the cosmological properties of the Universe, especially since lens-selection in sub-mm relies solely on the background, lensed source. Here, we aim to use ALMA to test our state-of-the-art method for finding lenses hidden inside the lower-flux regimes of sub-mm surveys. We use the near-infrared VIKING survey to look for foreground, lensing galaxies, expected to be bright in these colours. Initial analysis finds our method works robustly, however we require high-resolution imaging to confirm this. We stringently select 86 potential lenses from 20 to 80 mJy at 500 micron, and require 18.7 hours to identify their lensing nature, a method verified by our Pilot program. Not only can these measurements verify our method, they can also be a first measurement of the lensing probability at low flux densities. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2022-05-21T00:47:27.000 |
| 1328 | 2015.1.00369.S | 48 | The evolution of outflows from high-mass stars | We have performed a deep continuum survey with the JVLA at 6 and 1.3 cm, towards a sample of 60 high-mass star-forming cores. These belong to 3 different types that we believe to correspond to different evolutionary phases: hot molecular cores (HMCs), cold molecular cores with mid-IR emission (CMC-IRs), and without mid-IR emission (CMCs). Indeed, we find that free-free emission is detected only in 1 CMC out of 18 (6%), whereas detection rates of 53% and 91% are obtained respectively for CMC-IRs and HMCs, consistent with an age increase from CMCs to HMCs. Since in most cases the cm continuum emission has spectral index of 0.2-1 between 5 and 22 GHz and jet-like morphology, we conclude that we have identified a sample of thermal jets from massive young stellar objects (MYSOs). This is ideal to study the evolution of jet/outflow systems in the early stages of high-mass star formation. Our goal is to resolve the molecular outflows associated with a selected sample of 10 CMC-IRs and HMCs, and determine their physical parameters. By comparing the properties of the outflows of the two sub-samples (CMC-IRs and HMCs), we will determine how the outflow properties change with time in MYSOs. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2017-08-22T21:17:43.000 |
| 1329 | 2018.1.01006.S | 282 | Testing the Molecular Gas Thermometer: Mapping Irradiation Tracers in Two Helix Nebula Globules | Planetary nebulae (PNe) present fundamental examples of astrophysical plasmas and shock processes, and they serve as essential testbeds for studies of high-energy irradiation of cold molecular gas. The unparalleled sensitivity and mapping capabilities of ALMA will allow us to directly image the molecular content of globules within the Helix Nebula, one of the nearest and best-studied molecule-rich planetary nebulae. We propose spatially resolved observations targeting globules in the lines HCN, HNC, and other key species. By determining gradients of molecular irradiation tracers along the length of the globule filamentary structures, we will establish the effects of UV and X-ray penetrating power on the molecular chemistry of the nebula. The results of these observations, in combination with those of our recent line survey, will exploit the heretofore untapped potential of PNe for purposes of investigating the impact of high-energy photon flux on the chemistry of cold molecular gas. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2020-01-12T00:14:22.000 |
| 1330 | 2019.2.00054.S | 152 | Understanding the Full Disk Life Cycle and the Beginnings of Planet Formation | ALMA has greatly advanced our understanding of planet formation, yet we still lack a holistic view of the full disk life cycle in a single star-forming region, from the initial Class 0/I embedded stage (<1 Myr), to the Class II protoplanetary phase (1-5Myr), to the final Class III debris clearing stage (>5 Myr). Because planet formation is an ongoing process that likely begins early (<=1 Myr), obtaining this complete view is critical to understanding how planetary systems are assembled. Our team has completed ALMA surveys of the Class II and Class III disk populations in the Lupus star-forming region; here we propose an ACA survey of the Lupus Class 0/I sources in Bands 4, 6, 7, and 8 to construct robust SEDs and probe large spatial scales. These observations will be critical to our radiative transfer forward modeling to derive fundamental properties of these embedded disks, which we will compare to the protoplanetary and debris disk populations in Lupus. The end result will be the first complete view of the full disk life cycle in a single star-forming region with ALMA, providing much-awaited insights into the beginnings of planet formation. | Disks around low-mass stars | Disks and planet formation | 2022-08-24T15:28:18.000 |
| 1331 | 2016.1.00264.T | 1 | Revealing the magnetic structure of compact jets in Galactic black hole X-ray binaries | One of the biggest questions left in high energy astrophysics is the mechanism to form the relativistic jets from accreting black holes. Here we propose to carry out first TOO polarimetry of transient Galactic black hole X-ray binaries in the mm band, to study the magnetic field structures of compact, steady jets ubiquitously seen in low mass accretion rates. To trigger the observations, we monitor the X-ray lightcurves and spectra of our targets using the Japanese all-sky X-ray monitor MAXI. The ALMA's high sensitivity enables us for the first time to detect the polarized synchrotron component in the mm band and to constrain the magnetic field configuration at the base of the jets. We are also preparing for simultaneous multi-wavelength observations including X-ray, near-infrared and optical bands. They are expected to provide great synergy with the ALMA observations, by allowing us to reveal the structure of the inner accretion disk, as well as to estimate the magnetic field strength and energy distribution of electrons at the jet base. | Black holes, Transients | Stars and stellar evolution | 2018-03-01T20:37:23.000 |
| 1332 | 2011.0.00779.S | 0 | Characterizing Io's atmospheric composition and circulation v3 | Jupiter's moon Io is the most volcanically active body in the solar system and has a very thin and spatially variable atmosphere, mainly composed of SO2. The goal of this proposal is to adress several aspects of the atmosphere that are not well characterized : the nature and abundance of the minor species, the replenishment sources for SO and SO2, and the atmospheric circulation (wind). To bring unprecedented constraints on these questions, we propose to observe a rich portion of band 7 with the extended configuration and a fine spectral resolution. The excellent available sensitivity will allow to search for expected yet undetected volcanic species such as KCl, S2O, SiO and CO, for which the abundance measurement will put strong constraints on the volcanic regimes. Simultaneously, the strong lines of main species SO2 and SO will be mapped with an improved spatial resolution, with the objective to relate their spatial distribution to their possible respective replenishment mechanisms. Finally, we will measure Doppler-shifts on the strongest line to retrieve the best observation of the atmospheric wind-field. Io's atmosphere circulation has only been observed once so far, and the proposed ALMA observations are expected to provide a radical improvement on the wind measurement. | Solar system - Planetary surfaces, Solar system - Planetary atmospheres | Solar system | 2014-02-11T21:21:00.000 |
| 1333 | 2017.1.00042.S | 141 | Arp 220 Nuclear Disks at 0.027-0.05'' Resolution | We propose to complete our ultra-high resolution imaging of Arp 220 to resolve the gas structures and dynamics in the two nuclear disks. In ALMA Cycle 3, our project 2015.1.00113.S was scheduled for both long and short baseline imaging in the CO (1-0), (2-1) and (3-2) lines. This project was A-ranked but so far we have received only the CO (1-0) imaging. Although this project was carried over to Cycle 4, we do not know if it will be completed in Cycle 4; here we submit the uncompleted parts of the original project. In Cycle 5 which provides longer baselines, we also propose to augment the Cycle 3 CO (1-0) resolution by a factor 2 to 0.05'', and to obtain the remaining high resolution imaging in the CO 2-1 which will yield 4x higher resolution (0.027'') than the existing CO (1-0). This spectacular imaging will resolve physical radii down to 5 pc within the central gas concentrations and well within the sphere of influence of the putative super massive black hole. In addition, the CO line ratio and excitation analysis in Arp 220 an analog of high z starbursts and SMGs will provide a vital foundation for interpreting observations of high z mergers. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2019-01-04T21:30:48.000 |
| 1334 | 2016.1.00201.S | 1 | Magnetohydrodynamic mechanisms of jets in the solar chromosphere | Solar spicules are one of the jet phenomena regularly observed all over the solar limb in the chromosphere, that is an atmospheric layer between the visible surface, i.e. the photosphere, and the corona. Spicules are a manifestation of dynamic interaction of thermal convection below the surface, shock waves, and magnetic field. Quantitative understanding of chromospheric jets is important not only for understanding of the chromospheric phenomena themselves but also for the energy transport into the corona and the solar wind. Our observation target in this proposal is spicules in coronal holes on a solar limb. The observation would be done by the sit-and-state mode with C40-3 configuration in Band 6 and Band 3. The required duration is 2 hours with cadence of 2 sec for each band. Through these observations, we are going to try to detect (1) for more frequent ``ordinary spicules", shock waves at the feet that are direct driver of the jets, (2) for taller jets, a horizontal motion of the chromospheric plasmas as a manifestation of the twisting Lorentz motion. These features are predicted by our MHD numerical simulations. | The Sun | Sun | 2018-07-07T00:00:00.000 |
| 1335 | 2019.A.00036.S | 10 | Unveiling the outflow mechanisms in transitional millisecond pulsars: the ultimate observing campaign of PSR J1023+0038 | The discovery of three millisecond pulsars that swing between an accretion and a rotation powered state has challenged our comprehension of the evolution of accreting neutron stars in low mass X-ray binaries. We are coordinating the most extensive ever, strictly simultaneous, multiband campaign of the transitional millisecond pulsar PSR J1023+0038 during its current peculiar X-ray sub-luminous accretion disk state. We propose to observe this system with ALMA simultaneously with other telescopes to: i) assess whether the mm emission displays similar variability as observed at lower frequencies; ii) determine the spectral slope in the radio-mm-near infrared domain to probe the presence of a jet (and determine its properties) and to gain insight into the role of a putative pulsar wind in driving radio flares. The ALMA observations will be crucial to nail down conclusively the connection between mass accretion and ejection in this system and in the transitional millisecond pulsars in general. This ultimate campaign will advance our knowledge on the details of the process by which neutron stars evolve from the initial accretion state to the final rotation-powered radio pulsar state. | Pulsars and neutron stars | Stars and stellar evolution | 2022-01-27T09:56:03.000 |
| 1336 | 2011.0.00273.S | 0 | SN87A: A Unique Laboratory for Shock and Dust Physics | SN987A is a unique laboratory to study shock physics and particle acceleration, cosmic dust and element production. Despite intense observation over the last 25 years, outstanding questions remain which only ALMA can address, and signficant discoveries can already be made in Cycle 0. We propose to image the remnant of SN1987A in the four available bands, spanning a critical transition wavelength range: At 100GHz SN1987A's flux is dominated by nonthermal emission from a shocked circumstellar ring, but by 690GHz the flux is predominantly thermal emission from dust in the central debris. The proposed observations will constrain models for relativistic particle acceleration in shocks. They will yield the first resolved images of the supernova debris at sum-mm wavelengths. They have the potential to discover molecular line emission from both the inner debris and from the circumstellar ring, and to find evidence for emission by a central compact object. The observations will be path finders, establishing a synoptic baseline for a major campaign with the full array. | Supernovae (SN) ejecta | Stars and stellar evolution | 2014-02-07T19:31:00.000 |
| 1337 | 2019.1.00801.S | 66 | HCN formation in the innermost region of O-rich AGB stars | Asymptotic Giant Branch (AGB) stars are divided in two types, O-rich or C-rich. In the firsts, carbon atoms are mostly locked into CO and the chemistry is essentially oxygen-based. Oppositely, for the seconds, the chemistry is largely carbon-based for the same reason. This is true but not as simple. Various carbon-based molecules hava been observed in O-rich stars, and inversely, proving that AGB stars are far from thermochemical equilibrium. Non-equilibrium processes invoked are, either pulsationally-driven shocks in the inner wind, or photochemistry driven by the penetration of galactic UV photons. To date, we do not know which one is involving, or dominating, but we predict different behaviours, e.g. formation of unexpected molecules very close to the photosphere of the star in the first case, within ~5 stellar radii, or a bit further in the second. To discriminate, we propose to observe, in 3 O-rich AGB stars (R Leo, R Crt and IK Tau), the formation region of one of those unexpected molecules, namely HCN, with a high angular resolution of 50 mas. These data will provide a numerous number of constraints to the current AGB models and shed light on their complex chemistry. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2021-02-15T12:44:39.000 |
| 1338 | 2015.1.00456.S | 19 | Gas Dynamics and Clump Scaling Relations in High-Redshift SMGs | We propose band 7 observations of the [C II]157um emission and dust continuum in four z~4.5 sub-mm galaxies (SMGs) at the highest spatial resolution (C36-7; 0.04") available in Cycle 3. These SMGs are selected from our cycle-0 ALESS and cycle-1 ALMA-S2CLS surveys. Our goals are to measure the gas dynamics and the distribution and intensity of star-formation within these galaxies on ~200pc scales. Our science goals are to search for and measure the sizes, luminosities, velocity dispersions, and spatial distribution of the star forming regions within the ISM and relate their properties to the underlying gas disk dynamics and gas pressures. Addressing how the (in)stabilility of high-redshift, gas rich disks controls the formation and properties of star-forming regions is critical for developing models of galaxy formation, in particular to determine whether the prescriptions developed to describe star-formation processes at z = 0 are applicable in the dense and rapidly evolving ISM of gas rich, high-z galaxies. All of our targets have already been detected in continuum and in [C II] with ALMA from our previous observations in cycle 0/1. The total time request is 6.4 hours. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-12-08T18:09:01.000 |
| 1339 | 2018.1.01395.S | 10 | Witnessing the early stages of the formation of Super Star Clusters in the nucleus of the nearby starburst galaxy NGC253 | We have used 0.2" ALMA images of the HC3N vibrational excited emission (HC3N*) to reveal the Super-Hot Core (SHC) phase associated to Super Star Clusters (SSCs) in the nearby starburst galaxy NGC253. HC3N* emission is a direct probe of unobscured mid-IR emission since it is radiatively pumped by the dust heated by the protostars. The detected 7 unresolved SHCs with temperatures >230 K and high densities are tracing the proto-SSC phase just before massive stars ionize their surroundings. We estimate that proto-SSCs account for more than 1/3 of the total luminosity of the galaxy. However, our estimates are still very rough and better resolution and sensitivity are required to make robust estimates of the luminosities. We propose to image the nucleus of NGC253 in the HC3N* emission with 0.025" resolution and enough sensitivity to make accurate measurements of sizes, temperatures, masses and luminosities for all SHCs, and to derive temperature and density profiles for some of them. This data will provide a firm estimate of the contribution of the proto-SSC phase to the global star formation, and to test the predictions of the proposed scenarios for the formation of SSCs. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2021-02-12T18:33:55.000 |
| 1340 | 2019.1.00086.S | 60 | BOPS: B-field Orion Protostellar Survey | Interferometric polarization observations have found that magnetic fields play an important role during the star formation process. However, their relative significance in their environment and their role in stellar multiplicity remains poorly understood. The TADPOL survey represents the largest polarization survey for low-mass protostars (~30 sources), but these sources were a variety of ages and in diverse star-forming environments at various distances. We want to improve significantly on the TADPOL survey by observing a factor of two more sources within a single region with better sensitivity. We will observe 870 um dust polarization toward 57 young protostars in the Orion molecular cloud on scales of 400 to 2000 au. At these scales, the observations will uniformly probe the magnetic field structure in envelopes around the protostars. We will also map CO(3-2) outflows to establish the angular momentum axes of the protostars. Combined with ancillary data, we will investigate the origin of stellar multiplicity and understand the role of magnetic fields during the star-forming process. This survey will be the most statistically robust, high resolution polarization survey to date. | High-mass star formation, Low-mass star formation | ISM and star formation | 2022-05-06T00:00:00.000 |
| 1341 | 2013.1.00111.S | 56 | The extreme UV through ALMA's eyes: a unique probe of the ionizing power of starbursts and super massive black holes | The extreme ultraviolet (EUV) of starforming and AGN sources cannot be probed directly from the ground or from space; their EUV are thus very poorly constrained. Our recent theoretical work demonstrates that the mm/submm recombination lines of HI and HeII are excellent probes of the EUV: they have little dust absorption, they arise from H and He (thus independent of metallicity) and their fluxes depend linearly on number of EUV continuum photons. The He++ region (producing HeII emission) requires 54 ev photons, thus the EUV hardness is directly proportional to the HeII/HI flux ratio. We propose observations of HI and HeII in compact OB star regions and galactic nuclei (SgrA* and NGC 1068). These observations will demonstrate the potential of the HI and HeII lines -- opening a new observing window on the EUV. Themeasured hardness of the EUV spectra will provide critical input to starburstsynthesis models. Based on prior near infrared line detections, we confidently expect expect detectios of the line emission in both SgrA* and NGC 1068. In the former, ALMA will image the 10^4 K ionized gas at 0.2 arcsec resolution (0.01 pc radius) for the first time. | High-mass star formation | ISM and star formation | 2016-05-26T21:00:15.000 |
| 1342 | 2016.1.00177.S | 70 | Identifying molecular outflows in our neighborhood | We have recently obtained an objective Herschel-based selection of local galaxies with extremely high far-infrared surface brightness log(Sigma_FIR)>~11.75. Their few 100pc size nuclear regions host intense and obscured star formation and/or AGN. Such regions are likely to launch powerful winds, and indeed the sample includes some well known examples of outflows in the molecular and other phases. Here, we propose deep moderate spatial resolution ALMA searches for CO (1-0) outflows in the seven remaining southern (DEC < +10) targets of that sample. If successful, detections will open the door for unique studies of structure and physics of molecular outflows. Aided by the proximity of targets with scales down to 150pc/arcsec, these can help to understand how outflows work and achieve the important effects that are assigned to them by current galaxy evolution studies. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-03-30T10:56:57.000 |
| 1343 | 2017.1.00523.S | 453 | Gas accretion onto dense cores from early to late evolutionary phases of massive filamentary clouds | High-mass star forming clouds often exhibit filamentary structures in which dense cores of ~<10 Msun are embedded. In order to form high-mass protostars, these dense cores must accrete gas from the environment. Such a picture, if proven universal, alters the current high-mass star formation models. However direct evidence of accretion onto dense cores in filaments is rare. We have selected 8 massive filamentary clouds encompassing a variety of evolutionary phases, and obtained VLA, SMA, and IRAM-30m data. Dense cores of ~<10 Msun are found in the filaments. Velocity gradients along filaments and infall signatures along the line of sight are found with VLA and IRAM-30m data, but the insufficient angular and spectral resolutions prevent us from tracing gas accretion onto dense cores. Here we propose to use ALMA to observe optically thick HCO+/HCN, and optically thin H13CO+/NH2D lines, in order to study both radial and axial gas accretion toward dense cores in filaments and inform high-mass star formation models. | High-mass star formation | ISM and star formation | 2020-03-10T00:00:00.000 |
| 1344 | 2016.1.00481.S | 32 | Illuminate NGC 253 Nuclear Starburst by Ionized Gas Imaging with Parsec Scale Resolution | We propose a high angular/spatial resolution observation of thermal free-free continuum emission in 100 GHz (Band 3) together with a hydrogen recombination line (H40alpha) toward a nuclear starburst galaxy NGC 253 in the ALMA Cycle 4. Based on data taken in the ALMA previous cycles, we successfully assessed properties of ionized gas. However, the limited spatial resolution data have constrained us to do inaccurate estimation of those values. Observations with high spatial resolution down to the Galactic compact HII region scale (0.''07=1.1 pc) assisted by the long baseline capability will push back the past limitations, and they provide not only ionized gas properties with the least ambiguity but also essential insights on the nature of the starburst activity, especially number of young massive stars and star formation rate. | Starbursts, star formation, Galactic centres/nuclei | Active galaxies | 2018-11-08T20:58:28.000 |
| 1345 | 2021.1.01099.S | 14 | Revealing the Physical Properties of Fibers in the TMC-1 Filament | Filaments sometimes contain velocity-coherent subfilaments called fibers. The origin of fibers remains highly debated. Two schools of thought have been discussed so far. One is that the main filaments form first and they fragment into fibers. Another picture is that the fibers are gathered to form the main filaments. Here we propose ALMA Band-3 mosaic observations toward a nearby filament, TMC-1, containing ~21 fibers. Generally, fibers are expected to have widths of ~ 0.03 pc. The distance to TMC-1 is about 140 pc and thus our proposed observations can resolve the internal structures of the main filament and fibers with unprecedented high spatial resolution, 4" (= 0.003 pc). Then, we aim to constrain the role of the fibers in star formation process, using the velocity and density structures of fibers and the filament. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-12-20T20:06:43.000 |
| 1346 | 2016.1.00683.S | 133 | Black hole mass measurements in the most MASSIVE Galaxies | Massive early-type galaxies (ETGs), as the end point of galaxy evolution, are the subject of intense interest. Yet, their complex formation histories remain obscure. In lower-mass objects black holes (BHs) are strongly correlated with properties of the stellar bulge implying co-evolution between the BH and stellar components. The BH mass in massive ETGs, however, does not correlate well with galaxy parameters. The most massive galaxies and their central BHs therefore may have followed different evolutionary paths from their less-massive counterparts. We propose to observe the molecular discs that lie in the heart of four of the most massive molecular gas hosting early-type galaxies in the local universe, in order to estimate their SMBH masses. With these observations we can test the feedback paradigm, constrain the environmental dependance of SMBH-host galaxy relations, provide important cross-checks on SMBH mass measurement techniques and anchor studies of the SMBH - host galaxy relations which use molecular gas. In this way a short investment of ALMA time can help reveal more about the complex formation histories of the most massive galaxies in our universe. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2018-08-30T14:11:44.000 |
| 1347 | 2015.1.01395.S | 2 | Resolving Molecular Clouds in a Low Metallicity Galaxy | NGC 625 is a metal-poor dwarf galaxy whose unique combination of properties make it optimal for exploring the evolution of dwarf galaxies and of star formation. To start, as a low-metallicity, star-forming system with an intense radiation field and a high gas-to-dust ratio, it is an excellent astrophysical laboratory for studying the molecular interstellar medium (ISM) and star formation in an environment very different from spirals like the Milky Way. Distinguishing NGC 625 from other dwarfs are its complex neutral gas morphology and its prolonged star formation history. To understand its molecular ISM, we propose to map it in CO, which remains the leading molecule for determining the mass of molecular clouds and other global properties of the cold molecular ISM. Yet in low-Z galaxies, the CO luminosity is weak compared to high-Z galaxies. Fortunately, with ALMA, we have the powerful combination of high sensitivity and angular resolution to map molecular clouds in low-metallicity dwarfs beyond the Local Group. The goal of this proposal is to map NGC 625 in CO(1-0), in order to resolve and determine the properties of its giant molecular clouds. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-09-23T05:57:41.000 |
| 1348 | 2013.1.00937.S | 4 | Tracing the onset of star formation with ALMA | We propose to observe with ALMA six centrally concentrated, highly evolved starless cores in the cluster-forming Ophiuchus molecular cloud. The selected targets include cores both within and outside of the larger Oph filaments. Despite their highly concentrated single-dish submillimetre features and small-scale structure as probed by interferometric NH3 observations, 70 micron non-detections indicate that any embedded protostars are very low luminosity, with upper limits L_int < 0.1 L_Sun for most of the targets. The proposed observations will reveal the core structure at 0.25" resolution (30 AU) at 359 GHz continuum, and the core kinematics using the dense gas tracer H2D+, critical to identify rotation and infall in the dense gas. Finally, we will search for slow outflows potentially driven by embedded first hydrostatic cores or extremely young embedded protostars undetected at 70 micron. | Low-mass star formation, Astrochemistry | ISM and star formation | 2016-09-11T05:29:10.000 |
| 1349 | 2021.2.00099.S | 90 | Studying the Warm Gas in local Luminous Infrared Galaxies | This filler program targets ACA observations of the CO(8-7), (7-6), and (6-5) molecular gas line emission and continuum emission in bands 10 and 9, for a group of ten U/LIRGs. The main purpose of these observations is to recover and map the integrated gas at high J transitions of these galaxies for the first time at ~ 2'' (1 kpc), a factor of ~20 improvement compared to existing Herschel observations. We will reveal for the first time the morphology of the highest excitation CO gas that can be accessed from the ground, and along with matched resolution lower CO observations will provide the highest resolution low to mid-J CO SLED in local U/LIRGs. Modeling such SLEDs will provide accurate estimates of the density and temperature of the gas and overall mass content at 1kpc scales. | Merging and interacting galaxies | Galaxy evolution | 2023-07-22T16:29:53.000 |
| 1350 | 2019.1.00577.S | 10 | Searching for phosphorus-bearing molecules in the ejecta of supernova 1987A | Phosprhorus (P) is a crucial element for life as we know it, being a crucial constituent of biogenic molecules. It is created in massive stars and ejected in the ISM through supernovae. However, little is known about this element in space due to its low abundance, and many problems remain unsolved. In the last years, knowledge of its abundance in star-forming regions and evolved stars has considerably improved thanks to several new detections of P-bearing molecules. Atomic P has been also clearly detected in supernova remnants, but its measured abundance is much lower than expected to reproduce the P abundance in the ISM, and growing evidence suggests that a significant fraction of P could be in the form of molecules. We plan to observe the P-bearing molecules PN and PO in SN1987A, a unique laboratory to study the molecular composition of SN ejecta, in which recent ALMA observations have shown un unexpected high abundance of molecules thought to be formed similarly to PN. Our observations will put stringent constraints on the abundance of P at its source of production, and help to constrain supernova explosion models. | Supernovae (SN) ejecta | Stars and stellar evolution | 2022-11-08T08:05:10.000 |
| 1351 | 2022.1.01479.S | 131 | CO Excitation Across the Local Galaxy Population | Increasingly, extragalactic surveys trace the molecular gas with the CO(2-1) line. This relies on a down-conversion to the fundamental CO(1-0) line and too many studies simply assume average CO(2-1)/CO(1-0) line ratios (R21). However, recent studies find substantial R21 variation across and within galaxies. This has major implications for interpreting star formation scaling relations and characterizing the molecular gas. Before ALMA, R21 large sample studies were limited to poorer resolution and hampered by calibration uncertainties. This has restricted deriving firm quantitative conclusions. To take the next step, we propose new CO(1-0) observations to construct the first well-resolved, well-calibrated, and sensitive survey of R21 across a representative sample of 16 nearby galaxies. We will leverage public multiwavelength data to relate R21 variations to local conditions, galactic structure, and molecular cloud properties. ALMA observations are essential due to both their high angular resolution (~3 arcsec) and calibration stability. These observations will have major implications for key scaling relations and can be used to anchor large past and future CO(2-1) surveys. | Surveys of galaxies | Galaxy evolution | 2024-09-15T15:26:28.000 |
| 1352 | 2019.1.01822.S | 9 | The molecular gas of a multi-phase filament in the lobes of Fornax A | We propose to use the Atacama Compact Array (ACA) to study the distribution of molecular gas in a multi-phase gas filament at the outskirts of the nearby radio galaxy Fornax A. The 25 kpc long filament is located along a bridge of radio emission connecting the two giant radio lobes and at the edge of an X-ray cavity. The filament has been detected in Halpha as well as HI (3 x 10^7 Msun) and dust. Its properties are alike those of filaments of cooling gas detected around more distant and massive radio galaxies. The only exception is that those filaments are rich of molecular gas, too, while so far our target only has an upper limit. Here, we propose to observe the filament in 12CO(2-1) along its full extent (~4 arcmin), and resolve any molecular gas down to a molecular gas surface density of 1.0 Msun pc^-2. We expect molecular gas to be present as we already detect cool atomic gas and dust, although it is unclear how much of it might be present, and what its exact distribution and kinematics might be. Observing the molecular gas will enable us to quantify how gas is cooling within the filament and determine if star formation is on-going or may occur in this region. | Outflows, jets and ionized winds, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-03-09T15:10:08.000 |
| 1353 | 2018.1.00864.S | 7 | Resolving the first radio outburst from a young massive star | We have detected the first ever IR outburst from a young massive (>8 Msun) star (S255 NIRS3), which has important implications on our knowledge of the formation of early-type stars. The mere existence of an outburst favours models according to which massive stars form through disk accretion like their low-mass siblings. With a ~1yr delay with respect to the IR burst, we have detected also a radio burst that we have been monitoring from July 2016 to January 2018 with the JVLA, from 5cm to 7mm, and (on a shorter period) with ALMA and IRAM-NOEMA at 2 and 3mm. The radio emission has increased up to an order of magnitude and has been modeled with a fast expanding radio jet (Cesaroni et al. 2018). In the last JVLA image (Jan 2018) we have barely resolved the jet, unlike previous images with similar resolution. This proves that the observed flux increase is indeed due to an outburst causing expansion of the jet, as predicted by our model. We wish to resolve the jet with ALMA. For the first time, we will determine the physical structure of a thermal jet from a young massive star on scales below a few 100 au. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2022-10-29T20:54:56.000 |
| 1354 | 2016.1.00223.S | 63 | Dissecting the monolithic molecular core G31.41+0.31 | In a previous ALMA project we imaged the massive core G31.41+0.31 at 1.3mm with 0.2" resolution. The results provide us with contradictory evidence: on the one hand, (i) the core looks very homogeneous and appears to undergo solid-body rotation; on the other hand, (ii) we find evidence of rotation+infall that speeds up towards the core center, while the presence of two embedded massive stars suggests that fragmentation has already occurred. We believe that the apparent contradiction between (i) and (ii) can be due to large continuum opacity at 1.3mm and insufficient angular resolution. Therefore, to establish whether the core is indeed as monolithic as it appears, or is undergoing global fragmentation, we propose to: (1) improve on our previous 1.3mm images by increasing the resolution to 0.08", to resolve the absorption region and hence investigate the infall; and (2) extend the continuum imaging to 3mm, at the maximum possible resolution at this band (0.08"). At 3mm the dust opacity is up to 4 times lower and it should be easier to reveal fragmentation on scales of ~0.2", comparable both to the Jeans length and the separation of the two embedded massive stars. | High-mass star formation | ISM and star formation | 2019-01-11T18:52:56.000 |
| 1355 | 2016.1.00569.S | 135 | Characterizing Absorption-Selected High-z Galaxies (CASH) Survey | Our successful Cycle 3 proposal to detect [CII] emission from the highest HI column density absorbers (known as Damped Ly-alpha Systems; DLAs) at z~4 has resulted in the first two detections of this line for absorption-selected galaxies; a population of galaxies that traces 'typical' galaxies due to their unbiased selection technique with respect to luminosity. The current proposal expands on our pilot program by more than tripling the sample size. With this expanded sample, we will be able to definitively characterize the size, mass and impact parameter distribution of the galaxies responsible for the high metallicity end of the DLA galaxy population at z~4; an objective that has eluded all major observational facilities thus far. As a corollary, we will also be able to explore the metallicity dependence of the star formation rate (SFR) to total [CII] luminosity scaling relationship. We emphasize that targeting DLA galaxies has proven to be an effective way to detect [CII] emission from moderate to low star-forming galaxies (SFR > ~5 Msun/yr) at z~4, and thus complements the typical luminosity-based samples covering this SFR range. | Damped Lyman Alpha (DLA) systems | Cosmology | 2019-05-25T06:36:58.000 |
| 1356 | 2017.1.01076.S | 43 | A Protoplanet Interacting with an Edge-on Circumstellar Disk | We have discovered a companion to a very young star using HST. The object is projected at the outer radius of an edge-on protoplanetary disk and appears coplanar with the disk. Keck AO photometry indicates the object has the same temperature as brown dwarf GQ Lupi B but with 10x less luminosity - consistent with a planetary mass object. Keck AO spectroscopy detects 2.12 micron H2 emission from the companion, confirming its youth and excluding a background object. We propose band 6 continuum and CO isotopologue observations to 1) measure spatial and velocity asymmetries in the outer disk and show that the gas there is moving in a two-body potential; 2) detect a separate disk around the companion; 3) use disk rotation curve(s) to derive the mass of the component(s); and 4) resolve the disk vertical structure. With a substellar spectral energy distribution, accretion signatures (the subject of a pending HST proposal), and the demonstration of gravitational interaction with disk gas, this object would be established as the leading example of an accreting protoplanet at 100 AU and offer support to models of planet formation by gravitational instability. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2019-01-30T23:13:09.000 |
| 1357 | 2021.1.01495.S | 10 | Revolutionary insights into the z>7 gas and dust physics | Although high-z galaxy sample sizes with FIR line and dust continuum detections have known a boost with ALMA, the characterisation of their gas and dust reservoirs remains elusive. We propose to target six FIR lines ([OIII]52,88,[NII]122,[OI]145,[CI]370,CO7-6) and the underlying dust continuum in the brightest [CII]- and dust-detected z=7.306 galaxy (UVISTA-Y-003). This ambitious program will allow us to unambiguously constrain the gas densities, ionisation parameter, ionising photon escape fraction, molecular gas mass and gas-phase O, C and N abundances. We will gain unprecedented insights into the early metal and dust enrichment, the efficiency of star formation, and the contribution of massive galaxies to cosmic reionisation. The exquisite sampling of the rest-frame 52-370 micron dust SED comes for free, and will enable us - for the first time - to cover the z>7 dust SED peak and to constrain the dust temperature, mass and IR luminosity with high precision. The IR luminosity will be crucial to interpret the IRX-beta diagram; whereas the metal and dust masses will allow us to tie down the dominant dust production sources and the importance of gas accretion and outflows. | Starburst galaxies | Active galaxies | 2023-08-18T16:00:18.000 |
| 1358 | 2022.1.00728.S | 40 | Exploring the giant planet-forming potential of disks in the high UV environment of the Sigma Ori cluster | Detections of gaps and rings in protoplanetary disks have implied that giant planet formation occurs readily at separations of tens or sometimes even hundreds of au. Our current understanding of the demographics of giant protoplanets, though, has largely been shaped by high resolution observations of disks in the nearby low-mass star-forming regions Taurus, Lupus, and Ophiuchus. Snapshot surveys of regions with high UV radiation fields, which may be more representative of the formation conditions of our own Solar System, suggest that their disks are more strongly affected by photoevaporation compared to the nearby low-mass star-forming regions. To investigate how extreme environments can influence planet formation, we propose an exploratory high resolution study to characterize signatures of planet-disk interactions in the Sigma Orionis cluster. | Disks around low-mass stars | Disks and planet formation | 2024-08-18T22:58:04.000 |
| 1359 | 2021.1.01207.S | 21 | Uncovering the nature of an extremely optically dark SMG at z=5 | Among bright, dusty star-forming galaxies (submillimeter galaxies, SMGs), some are known to be the "optically dark" SMGs, which are completely blank at optical-to-near-infrared (NIR) wavelengths. Some are not detected even in deep IRAC images, and the nature and the role in galaxy evolution of these "extremely optically dark" SMGs is still unclear. We propose to observe CO(7-6), [CI](2-1), and [CII] for AzTEC26 at z = 4.568, which is an extreme case of the optically dark SMGs, using ALMA Band4 and Band7. Combining with the archival CO(5-4) and [CI](1-0) data, we will evaluate CO excitations (from CO(7-6) and CO(5-4)) and uncover gas kinematics (via [CII]). On the basis these clues, we will address the issues: (i) what causes the extreme faintness in the optical to NIR, and (ii) what stages of massive galaxy formation do they account for. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-06-07T03:31:34.000 |
| 1360 | 2016.1.00728.S | 22 | Characterizing the first directly imaged water snow-line in a protoplanetary disk | In ALMA Cycle 3, our group serendipitously imaged the water snow-line in the protoplanetary disk around V883 Ori, a 1.3 M_sun protostar undergoing a massive FU Ori accretion outburst (Cieza et al. submitted to Nature). Our Band-6 observations revealed a sharp break in optical depth at a location where the disk temperature reaches the sublimation point of water. At this discontinuity, the disk shows a clear change in the spectral index, as predicted by recent water snow-line models (Banzatti et al. 2015). Due to the enormous accretion luminosity, this water snow-line lies at > 40 au as opposed to < 5 au as typically expected for solar-type objects. The V883 Ori disk thus represents a unique opportunity to characterize the water snow-line using an ample frequency leverage at the highest resolution available for Cycle 4. Our immediate objectives are 1) Constrain the temperature of the observed water snow-line, 2) Investigate the role of viscous heating in the thermal structure of the V883 Ori disk, and 3) and test dust evolution models. The V883 Ori disk is so bright that our observations, including overheads, require just 1 h per band. | Disks around low-mass stars | Disks and planet formation | 2018-11-09T17:51:39.000 |
| 1361 | 2018.1.00046.S | 74 | An Unprecedented Census of the Molecular ISM in Starburst Galaxies at the End of Cosmic Reionization | We propose a full molecular line inventory in Bands 3 and 4 of four of the highest known redshift dusty starburst galaxies accessible by ALMA, at z~5.7, close to the end of cosmic reionization. Our previous ALMA spectroscopy in two DSFGs at similar redshifts, show striking results, anticipating a new era for molecular ISM studies in high-z galaxies. We expect to detect more than 40 lines of 13 molecular species in each object, tracing the full range of excitation conditions, heating mechanisms, outflow and dynamical signatures, and chemical enrichment pathways. At these rest frequencies, our observations will match and even exceed the sensitivity of local starbursts observed by Herschel/SPIRE. By exploiting high-resolution ALMA 870um continuum observations, low- and mid-J CO observations with ATCA and ALMA, [CII] emission from APEX, and full optical-to-radio SED coverage, these observations will stand as the definitive view of the ISM conditions in these objects, serving as an effective comparative study to local starbursts (e.g. Arp220) and intermediate-redshift analog systems (e.g. the Eyelash). | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-12-28T19:40:23.000 |
| 1362 | 2021.2.00129.S | 18 | The Nearby Evolved Stars Survey: quantifying the gas and dust return to the Galactic interstellar medium | Outflows of asymptotic giant branch and red supergiant stars drive local galactic chemical evolution. The Nearby Evolved Stars Survey (NESS) is a global project targeting a volume-limited sample of evolved stars within 2 kpc to constrain the physics driving mass loss. NESS includes ongoing JCMT (515 hr) and APEX (56 hr) surveys to observe CO(2-1), CO(3-2) and dust continuum from ~500 sources, and at the Nobeyama observatory (190 hr) for CO(1-0). We propose 12CO and 13CO(2-1) and (3-2) observations of the 207 NESS sources visible to the ACA that do not have archival data (total sample 301 sources). Combining the high resolution and large field-of-view of the ACA with data from the JCMT and APEX, we will thoroughly probe their inner shells, revealing the mass-loss history, geometry and the 12C/13C and dust-to-gas ratios. The large, volume-limited sample will robustly constrain the onset of mass-loss variations and asymmetry. All NESS data, including reduced data, catalogues, codes and model results will be publicly available. The NESS database is poised to become the authoritative source for evolved-star studies in the next decade, and the proposed ACA data will be a vital addition. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2023-05-12T19:16:43.000 |
| 1363 | 2023.1.01436.S | 0 | Redshifts for the Brightest High-z Dusty Sources from Nearly Half the Observable Universe | We seek redshift confirmation of outstanding lensed, sub-millimeter galaxy targets that we have found in an 18,000 sq. deg survey. This is a seven-fold increase in the sky area previously surveyed for such galaxies. Sub-millimeter galaxies have among the highest star formation rates in the Universe and occur at such early times that they can challenge our understanding of galaxy evolution. They serve as excellent targets for JWST characterization. Probing the progenitors of massive elliptical galaxies, our investigation addresses ALMA's science driver on the origin of galaxies. Our conservative, multiband selection uses data at 150 GHz, 220 GHz and Planck 857 GHz to generate a sample of 31 bright, dusty, and likely high-redshift candidates. Our pipeline independently finds nine galaxies with verified redshifts z > 3. We have cross-matched against extra-galactic catalogs to identify potential foreground lenses, and inspected optical images. ALMA provides an ideal facility to confirm the redshifts of these extreme objects: we propose spectral scans of ALMA band 3 to measure lines of CI and CO. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-01-26T15:40:34.000 |
| 1364 | 2017.1.01578.S | 0 | Can dynamics in the transition disk of HD 34282 create a spiral and/or a vortex? | The transition disk around HD 34282 shows strong indications of dynamics driven by a sub-stellar companion orbiting inside the disk: with previous ALMA and VLT/SPHERE (NIR) observations we have detected an inner cavity, a tightly wound one-armed spiral and an asymmetric enhancement that could trace a vortex. We propose to observe HD 34282 in band 6 at a spatial resolution similar to that of SPHERE (0.04'') to: [a] find the dynamical signature of the companion disturbing the CO velocity map; [b] determine whether the sub-mm disk indeed contains a vortex or a previously unresolved spiral as detected in the small grain disk surface with SPHERE. Radiative transfer and dynamical modeling will be applied to characterize the detected disk structures and explain their origin. This is the only transition disk ever detected that displays these three important tracers of a companion simultaneously. It is therefore bound to become an important benchmark for future hydrodynamical simulations. | Disks around high-mass stars | Disks and planet formation | 2018-12-09T05:30:41.000 |
| 1365 | 2024.1.01473.S | 0 | Outflow properties and structure in compact clumps: high-mass star formation in the Southern Outer Galaxy | We propose ALMA Band 7 (12m) and Band 9 (ACA+12m) observations of 3 compact clumps in the outer Galaxy, at a 2-5 kpc distance. The sources are identified as HiGAL compact sources associated to dense gas detected in CS(2-1) and present signposts of high-mass star formation in advanced evolutionary stages. Outflow emission was identified with APEX observations in SiO emission at 217 GHz, confirming the presence of shocked gas. ALMA observations in Band 7 reveal compact and high-velocity SiO emission, unresolved at the achieved resolution of 3.5". We aim to characterize the outflow emission, morphology and kinematics at resolutions of 0.5" up to 19" scales. The results will be compared with those for G331.512-0.10, a young molecular outflow and one of the most massive and energetic found in the inner Galaxy. The proposed targets are among the most luminous sources found in the outer Galaxy and their outflows are among the most energetic and massive we have found beyond the solar circle. They constitute a unique laboratory for the study of complex molecules and how the outflows present affect the star formation process in massive star formation regions in the outskirts of the Galaxy. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1366 | 2021.1.00898.S | 17 | The extremely peculiar globular cluster system of UDG GAMA-526784 and its implications | Observations of Ultra-Diffuse Galaxies (UDGs, with luminosities of dwarfs but sizes of giant galaxies) have picked up a lot of attention by the community. Two nagging problems are 1) the apparent lack of dark matter of some UDGs and 2) their anomalously abundant-and-bright globular clusters. The former is difficult to reconcile with a LCDM model of structure formation, while the latter is contrary to observations in any other galaxy. A newly discovered UDG may provide valuable insight towards solving both problems. This unique object has similar properties to typical UDGs, apart from a widely spread population of compact star-forming regions. Some properties of this galaxy are similar to those hypothesised by Silk 2019, who predicts the formation of massive globular clusters (GCs) and links it to the formation of UDGs that lack dark matter. We aim to measure the molecular gas content of the regions, constraining the depletion timescales and the expected final mass of the star clusters. With ACA we will constrain the molecular gas content and, possibly, dynamical state of the whole galaxy, assessing if it lacks dark matter. These are essential ingredients to test the Silk 2019 model | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2023-08-11T14:42:18.000 |
| 1367 | 2019.1.00500.S | 4 | A Moment of Truth with ALMA CN Zeeman Observations: Is Disk Accretion Really Driven by Magnetic Fields? | Magnetic fields are believed to be essential to the process of accretion in circumstellar disks. Attempts to measure the strength and morphology of disk magnetic fields through dust continuum polarization have so far proven unsuccessful; the observed polarization patterns in the disk could be better explained by scattering and radiative alignment. We propose to obtain measurements of the magnetic field strengths in the disks of AS 209 and V4046 Sgr through measurements of Zeeman splitting in the CN 2-1 and CN 1-0 transition lines. Zeeman splitting offers a direct probe of the line-of-sight magnetic field without contamination from scattering and radiative alignment. Observations of the disks magnetic fields will offer evidence for or against current theories of magnetically driven accretion. These observations would significantly advance the commissioning of future Zeeman observations for both disks and star formation. | Debris disks | Disks and planet formation | 2021-09-04T21:05:42.000 |
| 1368 | 2011.0.00087.S | 0 | Structure of the beta Pictoris disk in mm dust | We propose to image the brightest debris disk - beta Pictoris - with ALMA in band 7. The primary aim is to study the distribution of mm-size dust on scales from ~150AU down to ~10AU. This will enable us to delineate the location of the colliding planetesimals which are the ultimate cause of the debris cascade in such disks. This will be compared with the distribution of small grains seen in scattered light, the hot dust seen in the mid-IR and the location of the planet beta Pictoris b, in order to test existing models and improve our understanding of the archetype debris disk. The images will probe the mm-grain population of structures including the 100AU ring, outer disk, inner clumps and warp or inclined disk. Simultaneously we will be performing a deep search for emission from the circumstellar CO in the disk, probing the origin of the gas and the nature of the parent planetesimals. | Debris disks | Disks and planet formation | 2014-02-07T14:10:00.000 |
| 1369 | 2013.1.00214.S | 5 | CO observations covering the entire N55, the best example of stochastic self-propagating star formation, in Super Giant Shell 4 in the LMC | We propose here an ALMA observation of molecular gas toward an HII region, N55, in the Large Magellanic Cloud (LMC), which is a cometary-shaped GMC that is being affected by multiple supernova explosions. The Spitzer/Herschel images show peculiar features in this region; there are a lot of filaments and clumps entangled with a size scale of a few pc, and then this structure may be formed by an effect of shocks from the supernova explosions. It has been known that supernova explosions play an important role in evolution of the ISM to form dense structure in the molecular clouds, leading to star formation. In particular, the ISM evolution in the dwarf irregular galaxies, which are not affected by the density wave or arms, is expected to be affected by explosive events observed as shells and supergiant shells. The observations of N55 in CO lines enable us to derive detailed physical properties of the possibly induced star forming GMC, leading to an understanding of the role of the supernova explosions and filaments on star formation in molecular clouds. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2017-01-25T13:53:39.000 |
| 1370 | 2022.1.00207.S | 6 | Mapping magnetic fields at cloud scale | Models of massive star formation show that magnetic fields play a significant role, preventing fragmentation, slowing cloud collapse, and influencing the formation of accretion disks and jets. However magnetic fields are still poorly known, in particular at the initial stages of massive star formation. In the last years, we have built up a sample of high-mass star-forming regions for which we are performing a multi-scale study, from cloud scales to disk/jet scales, of the role of magnetic field. Our study combines polarization observations of masers and dust continuum at different spatial scales in 9 massive star-forming regions. We have almost completed the observations at core and disk/jet scales but still miss large-scale polarization observations to trace the magnetic field at cloud scales. These large-scale observations is what we propose to carry out here with ACA in Band 6. By comparing the magnetic field measurements at different scales, we will obtain a complete view of its properties in a significant sample of massive star-forming regions spanning a wide range of luminosities and will test the magnetic field consistency across different spatial scales. | High-mass star formation | ISM and star formation | 2025-03-22T15:44:45.000 |
| 1371 | 2023.1.01214.S | 0 | Circumnuclear Holes around Supermassive Black Holes | Galaxies and supermassive black holes (SMBHs) are likely co-evolving, and the most accepted paradigm is an evolutionary process that involves self-regulating feedback from active galactic nuclei (AGN). Recent high-resolution observations of nearby galaxies are revealing ~10-100 pc CO holes at their circumnuclear regions in 20 % of the galaxy, independent of their current nuclear activity. The origin of these circumnuclear holes are unknown, but their radii typically corresponds to the SMBH potential, suggesting that the SMBHs are the cause. If these holes are developed without powerful AGN, the SMBHs must be creating these holes through heating or dynamical effects. This suggests secular effects can impede accretion of gas, making it harder for AGN accretion to occur. To unravel the cause of these circumnuclear holes, we propose to observe the HCN(1-0), CO(1-0) and CO(6-5) lines in three galaxies with known CO(2-1) holes, to probe the presence of gas and analyse the physical state of the SMBH surroundings. The results will help to clarify the origin of circumnuclear holes, and thus will reveal direct evidence of their feedback even without a luminous AGN. | Merging and interacting galaxies | Galaxy evolution | 2025-01-22T13:11:44.000 |
| 1372 | 2018.1.01737.S | 7 | V* V1094 Sco: optically thin continuum observations for a rare giant multi-ringed disk | A key ALMA discovery is the unexpectedly wide variety of structures in protoplanetary disks. We recently serendipitously discovered a new, huge (dust outer radius of 300 AU) multi-ringed disk around V1094 Sco in ALMA Band 6 and 7 data. Recent VLT-SPHERE/IRDIS scattered-light and higher-resolution ALMA images also show rings and substructure in this disk, down to even smaller scales. Disks the size of V1094 Sco are rare; it is in the top 2% of Lupus disks by radius. With structure at many scales, and evidence for a radially varying spectral index, V1094 Sco can be a key probe of dust ring formation mechanisms. However, a key observable is missing: in Band 6, the inner 35 AU are optically thick, and the interpretation of the spectral index of the dust is ambiguous due to low spectral leverage. This prevents us from analyzing dust structure and grain growth in this crucial area. We propose ALMA observations in Band 3 at 0.057" resolution, imaging the dust in the center of this key object with an optically thin tracer for the first time. Our proposal combines VLT-SPHERE and ALMA observers to study the origin of multiple rings in disks. | Disks around low-mass stars | Disks and planet formation | 2021-01-18T00:49:41.000 |
| 1373 | 2012.1.00817.S | 0 | Hot HCN in LIRGs - probing the dusty core and dense wind | We propose band 7 ALMA observations of vibrationally excited HCN 4-3 v=1f and the rotational ground state v=0 to probe the hot dusty cores and outflow acceleration regions of three luminous LIRGs and ULIRGs. We know from dust models that effective HCN pumping can only occur for dust brightness temperatures T(dust)> 80 K which occurs only in the inner 10-50 pc of galaxy nuclei. Thus with the vibrationally excited HCN we can probe the very nuclear excitation and dynamics. We have selected three objects with luminous HCN emission, IR-pumped emission and evidence of massive molecular outflows. There is mounting evidence that molecular outflows are common in LIRGs and ULIRGs and are important feedback mechanisms for regulating star formation and the accretion onto supermassive black holes (SMBHs). The proposed observations enable us to study the very onset of the dense molecular outflow as well as probing inside the optically thick dusty atmospheres of buried AGNs or compact starbursts. Submm and mm vibrational lines are a promising new tool for studying the extreme, hot cores of luminous infrared galaxies and AGNs - near and far. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2015-06-05T19:20:20.000 |
| 1374 | 2019.1.00746.S | 6 | Pushing ALMA to the limit: 100pc imaging of spectacular [CII] cavities in a z=6.6 quasar host galaxy | Recently, we reported high spatial resolution (~0.076",410pc) ALMA imaging of the dust continuum and [CII] line in a luminous quasar host galaxy at z=6.6. The unprecedented high resolution of the observations reveals a complex morphology of gas within 3 kpc of the accreting central black hole. Strikingly, we locate impressive [CII] cavities in the gas distribution (with diameters of 0.5kpc), offset from the black hole. The current data are insufficient in resolution to determine if they are created by interactions with nearby galaxies (leading to broad tidal features), or due to energy injection by the central accreting black hole (leading to confined, narrow shock fronts). Given the brightness of the [CII] emission on 400pc scales, observations at an incredible 100 pc resolution (0.02" in C43-9/C43-10) to resolve the rims of the these cavities are now within reach. This resolution also matches the sizes of regions that give birth to super star clusters in the galaxy and will allow us to zoom into the central region harboring the black hole. The proposed observations will showcase the unprecedented capabilities of ALMA in studying a forming massive galaxy in the reionization epoch. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2022-11-26T00:09:54.000 |
| 1375 | 2019.1.00949.S | 77 | A triple-image HST-dark but IRAC and ALMA-detected galaxy behind a lensing cluster | Mounting evidence suggests that HST-dark galaxies are the progenitors of massive galaxies in their early forming phases, which are totally missed in the deep HST/WFC3 surveys. However, obtaining their spectroscopic redshifts becomes the current bottleneck because of their faintness in optical/near-IR and moderate (sub)mm fluxes compared with classical SMGs. Here we propose to use ALMA to obtain an unambiguous spectroscopic redshift of a triple-image HST-dark but IRAC and ALMA-detected galaxy system behind the lensing cluster MACS J0417.5-1154, by scanning for CO and CI lines in the Band-3 and 4 frequency ranges (~27 GHz each). This is one of the early, surprising outcomes of the on-going cycle-6 large program ALMA Lensing Cluster Survey. Our lens analysis indicates that this is an intrinsically faint (S_1.2mm ~0.6 mJy) HST-dark galaxy and observed as 3 bright (2-4 mJy) counter images, providing us with a unique target for the detailed study of HST-dark population. With the spectroscopic redshift, we will know the accurate magnification factors and therefore physical quantities such as stellar mass and gas mass, which are crucial to advance our study. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2021-04-22T15:55:48.000 |
| 1376 | 2019.1.01153.S | 7 | Localizing active deuterium fractionation chemistry in a planet-forming disk | Molecular D/H ratios are commonly used as probes of the thermal history of Solar System volatiles, but it is currently unclear whether elevated D/H ratios originated in the Solar Nebula or in the pre-Solar cloud. Previous ALMA observations of DCO+, DCN, and N2D+ have revealed an active deuterium fractionation chemistry in analogs to the Solar Nebula, i.e. in protoplanetary disks. Whether the observed disk deuterium fractionation chemistry affects the composition of forming planetesimals is yet unclear, however, due to poor constraints at which disk elevation the observed molecules originate. To address this question we propose to observe DCN and DCO+ 2-1 in the disk of TW Hya. When combined with exisiting observations of 4-3 and 3-2 lines, the new observations will put tight constraints on the excitation conditions of DCN and DCO+ in this well-studied disk, and further whether they originate in the planet-forming disk midplane, elevated molecular layer or disk atmosphere. These observations will also link DCN and DCO+ abundances with specific disk thermal environments, enabling us to use these molecules as accurate probes in disks with fewer line observations. | Disks around low-mass stars | Disks and planet formation | 2022-05-06T16:26:35.000 |
| 1377 | 2018.1.01601.S | 18 | The Making of a local galaxy cluster: star formation and AGN feedback in a proto-cluster at z=1.69 | We recently discovered a galaxy proto-cluster candidate around a FRII radio-galaxy at z=1.69 in the deep, multi-band field around the z=6.3 quasar SDSSJ1030+0524. Archival VLT/MUSE data covering the Eastern part of the system show an overdensity of blue star forming galaxies at this redshift. Most of these galaxies are distributed in an arc-like structure around a region of diffuse X-ray emission, possibly hot gas shock-heated by the FRII jet. This may argue for a causal connection between the energy released by the AGN and the on-going star formation (positive feedback). To map the overall distribution of proto-cluster members and confirm the possibility that feedback from the AGN is promoting star formation among them, we propose to observe with ALMA the entire field around the FRII galaxy and detect CO(2-1) emitters at z=1.69. Similarly to what is observed in the z=2.2 Spiderweb proto-cluster, our observation will also probe any reservoir of cold gas extending on tens of kpc scales around the central radio-galaxy and/or distributed across the entire proto-cluster, hence revealing the interplay of feedback and star formation at the peak formation epoch of galaxy clusters. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2020-03-04T20:43:19.000 |
| 1378 | 2015.1.01178.S | 10 | ALMA Observations of z~6.7-6.8 Galaxies with Strong Optical Nebular Emission: Re-Evaluating ALMA's Potential for Detecting z>6 Galaxies | ALMA is expected to change our view of the high-redshift Universe: Because of the strong negative K correction, ALMA continuum imaging should be able to detect a z~10 galaxy as easily as a z~1 galaxy for a given infrared luminosity; Also, the strong [CII] 158 um line is expected to serve as a great redshift marker and a star-formation indicator, especially at z>6, where the intergalactic medium (IGM) becomes increasingly neutral and heavily absorbs Ly-alpha emission. Despite this great expectation, detecting z>6 galaxies with ALMA remains challenging, suggesting the possibility that galaxies at such high redshift may be rather poor in dust and metal. To address this issue further, we propose to observe two bright z=6.7-6.8 galaxies with ALMA. These galaxies are cluster-lensed, so their intrinsic SFRs are ~10 Msun/yr or less. Also, they show a sign of having strong nebular emission in the rest-frame optical. Together, these factors may increase the chance of [CII] and dust continuum detections, thereby shedding new light on the properties of z>6 galaxies. This is a Cycle 2 Priority B program with a time allocation of 6.5 hours, but no data have been obtained so far. | Lyman Alpha Emitters/Blobs (LAE/LAB), Gravitational lenses | Galaxy evolution | 2017-05-02T21:03:30.000 |
| 1379 | 2022.1.00958.S | 33 | Lord of the rings: the effect of dust traps and snowlines on the composition of planet forming material | Almost all disks observed at high angular resolution show signs of ongoing planet formation but the formation mechanism and location of these planets remains unclear. The chemical composition of planets is set by the elemental abundances in the disk. The gas-phase elemental abundances in disks change drastically at the CO and H2O snowlines. Furthermore, pressure bumps in the disk trap the dust and with it ices preventing inward radial drift. Therefore, the location of the dust trap with respect to the snowlines is crucial in setting the composition of the gas available to planets. We propose to observe three transition disks where the CO snowline is expected to be inside the dust trap, thus trapping CO ice at large radii. We will compare these to archival data of disks where the CO snowline is outside the dust trap. In our sample, we first locate the CO and H2O snowlines using chemical tracers (N2H+, HCO+). Second, we quantify the elemental C/O abundance ratio using C2H observations. These observations will assess the effect of dust traps on the chemical composition of the planet forming material, a crucial ingredient to understand where the exoplanets observed to date have formed. | Intermediate-mass star formation | ISM and star formation | 2023-10-16T13:33:16.000 |
| 1380 | 2018.1.00492.S | 13 | Interactions, Runaways, and Explosive Outflows from Compact Groups of Forming Massive Protostars | We propose to image three NEW candidate explosive protostellar outflows with ~500 AU linear resolution in CO 2-1, SiO 5-4, other molecules, H30-alpha, and the 1.3 mm continuum. These massive star forming complexes are at distances of 1.5, 2.8-3.7, and ~3.7 kpc, contain massive and powerful outflows, multiple H2 fingers, and/or `bullets with morphologies similar to Orions BN/KL outflow. The BN/KL outflow located ~0.1 pc behind the Orion Nebula was powered by the dynamic interaction of several stars that resulted in their ejection as runaways. Our ALMA 1" images reveal hundreds of CO and SiO streamers expanding from the stellar ejection site with speeds of up to 150 km/s. ALMA observations of the three NEW targets will measure their energy and momentum inputs, locate their sources, and constrain the lifetimes and rate of explosive outflows. These powerful outflows represent a new type of feedback in massive star forming regions and contribute significantly to the self-regulation of star formation. Such protostellar explosions may be responsible for some recently detected luminous infrared-only transients observed by the Spitzer Space Telescope in nearby star-forming galaxies. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2020-10-03T17:30:51.000 |
| 1381 | 2018.1.01031.S | 169 | Revealing dust processing in the young supernova remnant 1E\,0102.2-72129 in the SMC | Oxygen-rich supernova remnants (SNRs) are observed within a few thousand years after a core-collapse supernova, prior to significant mixing of the SN ejecta with interstellar gas. They provide clues into stellar nucleosynthesis in massive stars, SN explosion mechanisms, and dust processing by/in core-collapse SNRs. Here, we propose to map the cold dust in the O-rich SNR 1E0102.2-7219 using 4 ALMA Bands to 1) accurately measure for the first time the mass and distribution of newly synthesized dust in un-shocked ejecta in this system, 2) track the processing of this newly synthesized dust as it encounters the reverse shock, and 3) characterize the cold dust, CO, and C, associated with a torus of ejecta surrounding the recently identified central compact object in the system. This dataset will be complemented by existing VLT/MUSE, HST, Chandra, Spitzer and Herschel datasets. These observations will provide new observational constraints regarding the formation and destruction of dust in the wake of core-collapse supernovae in the low metallicity environment of the SMC, with implications for the dust formation in the early Universe. | Supernovae (SN) ejecta | Stars and stellar evolution | 2020-11-26T19:03:05.000 |
| 1382 | 2016.1.00605.S | 0 | Polarization of SNR 1987A: probing the shock structure and the compact remnant | Polarization of the synchrotron emission from supernova remnants (SNRs) gives insight into the mag- netic field properties, particle acceleration mechanisms at the shock front, asymmetry, and evolution of the compact remnant. Supernova (SN) 1987A in the Large Magellanic Cloud, the brightest SN in 400 years, is a unique laboratory to investigate polarized emission generated by the elusive compact remnant and by the shock front. Polarization is critical to accurately locate a possible pulsar wind nebula, and to correlate the degree of efficiency of the particle acceleration process with the topology of the magnetic field. ALMA Cycle 4 Full Polarization observations, with resolution of 10% of the remnant size, provide the opportunity to detect polarized emission in SNR 1987A for the first time. | Supernovae (SN) ejecta, Pulsars and neutron stars | Stars and stellar evolution | 2019-07-17T21:48:43.000 |
| 1383 | 2015.1.01415.S | 10 | Outflow launching scales in a Class I protostar | In this program we will investigate the innermost regions of a Young Stellar Object to trace the kinematics of the molecular gas very close to the launching point of the protostellar outflow. With ALMA in its largest configuration currently offered, it is now possible for the first time to directly trace molecular gas at the relevant spatial scales, i.e., radii of ~3 AU. We aim to discriminate whether outflow launch regions are confined to a few stellar radii or that extended disk winds also play a role. To achieve this, we will directly compare our ALMA spectral line profiles, at unprecedented angular resolution, with our numerical simulations that are specifically developed with the aim of simultaneously resolving small outflow launching scales as well as larger, traditionally observable length scales. At the same time, our observations will be sensitive to disk rotation signatures, allowing us to determine any deviations from pure Keplerian rotation in the very inner disk. This would have implications for our understanding of protostellar disk dynamics. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2016-12-10T16:28:34.000 |
| 1384 | 2016.1.00162.S | 36 | Millimeter and Submillimeter Polarization of Disks: Direct Emission or Scattered Light? | HL Tau is the only known T Tauri Star to have a resolved polarization detection in the disk. Since grains align with the magnetic field, polarization from dust emission is typically thought to trace the magnetic fields. However, in the last year four theoretical papers have suggested that polarization at (sub)millimeter wavelengths may be due to Rayleigh scattering off grains in a disk. Currently, we are unable to determine if polarization from disks is from scattering, grain alignment, or a combination of the two. ALMA has observed many 10s of hours of polarimetric observations toward disks already, but none of these observations can truly distinguish between different polarization mechanisms, making it very difficult to interpret any of these observations. We propose to observe polarization in the disk of HL Tau. With deep, high-resolution, and multi-wavelength polarization observations, we will be able to take into account morphological, wavelength-dependent, and optical depth effects, and we will accurately determine whether polarization from disks comes from scattering, grain alignment, or a combination of the two. | Disks around low-mass stars | Disks and planet formation | 2018-08-08T00:47:25.000 |
| 1385 | 2017.1.01006.S | 35 | Cores on the cusp of star formation | We propose to observe with ALMA two nearby, centrally concentrated cores in the Ophiuchus molecular cloud on the cusp of forming a low mass protostar or first hydrostatic core. Despite lacking detected protostars, ALMA Cycles 0 and 2 observations reveal compact continuum condensations (< 1", or 140 au) embedded within elongated structures toward both cores. The proposed continuum observations in Bands 3, 4, and 7 will reveal the core structure at matched 0.6" resolution (80 au) to determine the dust emissivity, masses, and density profiles via radiative transfer modeling. We will also perform a suite of molecular line observations at 1" (140 au) resolution to i) use the gas kinematics to to measure infall, and distinguish rotationally-supported disks from collapsing pseudodisks; ii) determine the deuterium fractionation of HCO+ and N2H+ across the cores to constrain the luminosity of any undetected, embedded source; and iii) confirm the tentative lack of low-velocity outflows. These proposed observations will provide, for the first time at ~100 au scales, comprehensive physical, kinematic, and chemical pictures of two rare cores caught at the earliest stages of star formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-02-17T23:56:04.000 |
| 1386 | 2016.2.00115.S | 42 | Star formation inside galactic outflows: properties of the associated molecular gas and star formation efficiency | While galactic outflows are generally invoked to suppress star formation, recent models have proposed that the outflowing molecular gas can undergo star formation. This new star formation mode would have fascinating important implications, since the stars formed in the outflow would have high radial velocities, hence this mode may contribute to the morphological and dynamical evolution of galaxies. We have recently discovered evidence for star formation occurring in the outflow of a nearby galaxy. Stars are forming at a rate of about 15-30 Msun/yr and with radial velocities of a few hundred km/s. We propose to characterize the properties of the molecular gas in this star forming outflow with a 7m-array exploratory programme aimed at observing multiple CO transitions and a few tracers of the dense molecular gas. The goals of the observations are: 1) obtain a first assessment of the content of molecular gas and of its distribution in the outflow, hence providing the star formation efficiency of this new mode of star formation; 2) characterize the properties of the outflowing molecular gas, hence shedding light on the conditions that enable star formation in this unusual environment. | Outflows, jets, feedback | Active galaxies | 2018-11-17T19:51:57.000 |
| 1387 | 2022.1.00522.S | 40 | ALMA [OIII]88um Spectroscopy for the Most Luminous Galaxy Candidate at z~10 | We propose [OIII]88um observations for an extremely luminous galaxy candidate, XMM3-3085 at z~10.2, whose high redshift is suggested by recent HST grism spectroscopy. XMM3-3085 is the most luminous galaxy candidate at z>10, and such a luminous system is not expected theoretically, indicating an unusually vigorous period of early star formation. Importantly, the progenitors of such luminous systems would then be readily within reach of JWST. Noting ALMA's demonstrated role in confirming redshift estimates from HST and ground-based campaigns, we request a modest allocation to confirm the HST-based redshift using [OIII]88um for this remarkable z>10 source. Confirmation would permit more ambitious joint spectroscopic campaigns exploiting both ALMA and JWST on a timely basis, thereby strengthening evidence for a rapid emergence of luminous primeval systems. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-10-06T14:54:12.000 |
| 1388 | 2018.1.00085.S | 88 | The ISM at z~7: Deploying a successfully piloted technique to find the brightest [CII] emitters at z>6.5 | Astronomers have long anticipated using [CII] to pursue a physical study of galaxies in the epoch of reionization. Yet current probes with ALMA have had a low yield in identifying bright [CII] emission at z>6. Perhaps this could be due to the almost exclusive targeting of galaxies with spec-z's from Lyman alpha? Seeking a different approach, we recently executed a pilot program pursuing efficient line scans on two luminous galaxies at z~7. Amazingly, with just 1 hour of observations, 2 >=6 sigma [CII] lines were found, exceeding the luminosity of all prior detections in z>6.1 galaxies. The surprising success of our pilot suggests that luminous [CII] galaxies do exist at z>6, but perhaps not in those galaxies showing Lyman-alpha emission. Here we propose to extend our pilot program to target 6 more extremely luminous galaxies at z~7 with precise photometric redshift constraints (leveraging 2 sharp spectral features). Our program would measure redshifts for sources, constrain the masses of the brightest galaxies at z~7, and allow for an extensive suite of follow-up activities. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-02-22T17:17:58.000 |
| 1389 | 2012.1.00681.S | 5 | Locating the CO Snow Line in Protoplanetary Disks | Snow lines, or condensation fronts, in protoplanetary disks are key ingredients in planet formation models and locating the snow lines is important to enhance our understanding of the structure of planetary systems. We propose to locate the CO snow line in the protoplanetary disks by searching for the signatures of CO freeze-out: 1) directly imaging the C18O 2-1 radial brightness change due to the CO freeze-out in the nearly face-on disk of TW Hya, and 2) resolving the N2H+ 3-2 emission to investigate whether N2H+ traces the CO snow line in the disks of TW Hya and HD 163296. The proposed observations will put strong constraints on our understanding of disk temperature profiles, and potentially provide a powerful chemical imaging tool to constrain CO snow line locations in large samples of disks. | Disks around low-mass stars | Disks and planet formation | 2015-08-01T15:36:52.000 |
| 1390 | 2018.A.00046.S | 246 | The host properties and environment of high-redshift radio galaxies with ACA | It is now accepted that radio-emitting jets might be one of the main ingredients shaping the evolution of massive galaxies in the Universe. There is wide observational evidence that the super-massive black holes responsible for such jets reside in the most massive galaxy population, which in turn reside in large scale structures. This trend seems to have settled long time ago, making radio-AGN a natural lighthouse of such structures in the early Universe. However, pinpointing these early radio-AGN and studying their hosts has been harder to accomplish, with only recent reasonable numbers of radio-AGN host studies coming to light at z>2. This proposal aims to provide a statistical understanding of radio-AGN found within 4deg2 in the ELAIS-S1 field known to have the lowest foreground contamination, hence ideal for mid-IR observations with JWST. We propose to observe 41 high-redshift radio-AGN (selected either via their ultra-steep radio spectrum or extreme IR-to-radio flux ratios) at 1.3mm with ACA down to rms=0.2mJy. The ACA field of view will in addition allow us to assess the star-formation activity in the local environment of these galaxies (within a radius of ~180kpc at z~2). | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2019-07-30T00:00:00.000 |
| 1391 | 2016.1.00656.S | 51 | Filling the gap of CO line emission detections at high redshift | We propose to obtain CO emission maps on 5 strongly lensed main sequence galaxies at redshifts between 1 and 2.5. Similar studies have been done mainly in the most massive and highly star-forming galaxies that represent a small fraction of the full SFR density of the Universe. These observations will allow us to characterize the molecular gas content in galaxies with intrinsic SFR lower than 100 solar mass per year. This type of galaxies, until now, have been elusive in the detection of molecular gas. The lensing power and good models of the Hubble Frontier Fields galaxy clusters allow us to explore a new range of 1-10x10^9 Msun galaxies, which is out of reach in CO for ALMA. Besides the gas mass, we will be able to obtain depletion times, dynamical mases, CO distribution sizes and star formation effiencies in galaxies comparable to local spirals. The observations will reveal how the process of transorming molecular gas into stars evolves from z~2 to z~0. | Gravitational lenses | Cosmology | 2018-05-05T19:03:44.000 |
| 1392 | 2023.1.00792.S | 0 | Identifying HI-absorption-selected galaxies at z~4 | The relation between the HI reservoirs traced by high-z damped Lyman-alpha absorbers (DLAs) and their associated galaxies has been an open question for 3 decades. ALMA CII-158-micron searches have obtained the first identifications of such HI-selected galaxies at z~4, finding a number of surprises, including a high detection rate of CII-158 micron emission in high-metallicity ([M/H]>-1.35) DLAs, large impact parameters to the DLA sightlines suggesting absorption in the CGM, and the first case of a cold disk galaxy at z>4. We propose to use ALMA to search for CII-158-micron emission from galaxies associated with all z>3.6 DLAs in the ALMA sky with [M/H]>-1.35. The proposed observations will double the number of high-metallicity DLAs with such searches, allowing us to identify the associated HI-selected galaxies and test whether high-metallicity DLAs continue to show a high CII detection rate, test whether extended, enriched HI envelopes are a generic feature of high-z galaxies, identify candidate rotating disk galaxies at z~4, and compare the CII emission and low-ionization metal absorption lines to trace the large-scale dynamics of the HI-selected galaxies and their CGM. | Damped Lyman Alpha (DLA) systems | Cosmology | 2025-04-05T16:49:13.000 |
| 1393 | 2019.A.00003.T | 180 | Gravitational millilensing as a tool for studying the microarcsec-scale structure in PKS1413+135 | We have recently identified a new type of symmetric achromatic variability in light curves of active galaxies, which we suggest to be due to gravitational lensing. This allows us to probe lenses in the mass range of 10^3-10^6 solar masses, which have been challenging to detect with other methods. We propose ACA standalone mode observations of the radio source PKS 1413+135, which has previously shown five SAV events in its light curve over the past 27 years and which shows indicators that a new event has recently started and will be observable during cycle 7. The main goal of this proposal is to find out if the variations are achromatic up to 345 GHz (band 7) frequencies. We request 22 observations separated by approximately 14 days to monitor the flux density evolution during the event. Depending on the outcome, we have a unique opportunity to study gravitational milli-lensing, plasma lensing or intrinsic variability in relativistic jets. | Gravitational lenses | Cosmology | 2022-01-28T15:17:28.000 |
| 1394 | 2024.1.01605.S | 0 | Constraining dust temperature and determining the maximum grain size outside of the water snowline in Class II disks | An SMA survey has observed uniform, low (~2) (sub)millimeter spectral indices among 47 Class II objects in the Taurus-Auriga region, which indicates that the flux density is dominated by optically thick (sub)structures. Based on the optically thick dust slab model, which considers dust self-scattering, their population synthesis has narrowed down the maximum grain size to: (1) 0.1 mm when average dust temperature is 100 K (2) 3.0 mm when average dust temperature is 24 K. To further resolve the degeneracy between maximum grain size and dust temperature, we propose ALMA Band 8 and Band 9 observations on the 27 Class II objects in the SMA sample. The new observations will help determine whether the observed ~2 spectral indices result from a maximum grain size of 0.1 mm or a low dust temperature. This new constraint will contribute to the central debate surrounding dust coagulation outside of water snowline: whether the bouncing/fragmentation barriers prevent dust grains from growing larger than 100-micron sizes. These findings will also provide crucial constraints on grain growth efficiency and dust stickiness in both theoretical and experimental perspectives on planet formation. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 1395 | 2015.1.01133.S | 5 | Harnessing the power of CI as a tracer of H2 in starburst galaxies | Molecular gas fuels star formation and is a key driver of galaxy evolution. Unfortunately, gas mass estimates rely on the optically thick rotational lines of 12CO, where the relationship between line emission and column density quickly breaks down. Furthermore, in extreme star formation environments, UV-fields and cosmic rays act to diminish CO as a H2-tracer.We propose 0.7" imaging of the fine-structure line of atomic carbon, CI(3^P_1 - 3^P_0), towards the central starburst in NGC253. This will be the first sensitive CI map of a starburst galaxy, it will resolve molecular clouds (~20pc) and yield the most detailed study to date of CI in extreme starformation conditions. Using CI-to-H2 conversion factors predicted by our state-of-the-art simulations, we will infer H2 column densities across the region. These will be compared with results from the optically thin CO isotopologues - and from the dust emission - in order to, for the first time, calibrate CI as a H2-tracer on ~20pc scales in an intense starformation environment.Our findings will have significant implications for high-z studies of starburst galaxies where CI could replace CO as a tracer of H2. | Starbursts, star formation | Active galaxies | 2017-08-31T16:38:09.000 |
| 1396 | 2023.1.00038.S | 0 | Complex organic imaging towards G+0.693-0.027, the ISM COMs Rossetta Stone | During the last 5 years, the source G+0.693-0.027, in the Sgr B2 Galactic center complex, has become one of the most prolific molecular emitters with more than 120 species detected today. Moreover this source is a strong complex organic molecule (COM) emitter, with many detected species of prebiotic interest. Although the molecular abundances are well constrained with unresolved single-dish observations, it is obvious from shallow interferometric observations that the understanding of the ISM chemical processes requires the spatial information probing the association between species. G+0.693-0.027 is likely the best source to provide this information due to its observed 10''-20'' extended emission, well suited for ALMA observations. The low excitation in this source provides a clean spectrum, different from the line crowded observations towards hotter sources. The advent of ALMA Band 1 is ideally suited to study the distribuiton of prebiotic COMs like ethanolamine, and even to detect or obtain robust limits to the detection of glycine and its isomers. Here we propose a very deep Band 1 observation towards G+0.693-0.027 to probe, for the first time, the origin of ISM COMs. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1397 | 2023.1.00185.S | 0 | Confirming the presence of star formation in the most luminous quasars | The FIR continuum emission from quasar host galaxies is generally considered to be an indicator of the amount of their star formation with little contribution from dust heated by the quasar itself. Recently, it has been shown using ALMA that the most luminous quasars at z~2 have SFRs (based on rest-frame 285um luminosity) consistent with the star-forming galaxy population. However, there are claims, based on simulations, that AGNs can heat dust, even over galaxy-wide scales, above that produced by the torus, thus SFRs can be overestimated if based solely on the FIR luminosity. Here, we aim to test this by measuring whether the star formation is within dense molecular gas by mapping the CO (J=5-4) emission on galaxy-wide scales at high signal-to-noise for three of the most luminous quasars at z=2 with ALMA continuum measurements already available. Resolution of this issue has wide implications on AGN science with ALMA, particularly the role of quasar feedback in quenching star formation. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-09-23T18:06:27.000 |
| 1398 | 2011.0.00172.S | 0 | The Life Cycle of the Molecular Gas in the Nearest Nuclear Starburst: GMCs, Molecular Superwind, and Feedback v2.5 | We propose to observe NGC253, the nearest nuclear starburst, with early ALMA: with a modest investment of ALMA ES band 3 we will measure two key parameters fundamentally related to the evolution of starbursts: 1) the mass and energetics of the molecular gas entrained in the galactic superwind, thought to be the main way to quench massive starbursts, and 2) the properties of Giant Molecular clouds, thought to drive the high star formation efficiencies in a starburst. These goals require a 7-point CO (1-0) mosaic using the compact configuration covering the launching point of the wind and the H-alpha streamers, and a 3-point mosaic targeting high density tracers (one spectral setting) centered on the nuclear starburst and including the nearby region of the bar. The proposed setups will result in a >10-fold increase in sensitivity over existing data on a significantly larger area. The resulting images will provide a visually stunning illustration of early ALMA capabilities. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2013-06-19T19:41:00.000 |
| 1399 | 2017.1.01542.S | 75 | Outflow and Infall to Massive Protostars | We propose to investigate the outflow and infall phenomena in 8 sources which are part of a larger MIR/FIR sample already observed with SOFIA-FORCAST as part of the SOMA survey. These observations will allow us to understand how the infall/outflow processes depend on the evolutionary stage of the source and to place constraints on parameters such as the mass loss rate and infall velocities, which are needed to test models of high-mass star formation. Additionally, these data will provide the necessary molecular counterparts to the smaller-scale ionized jets and/or photoionized hypercompact HII regions from our cm-wave observations. This will allow us to study their association at the proposed resolution of 1.2". We will also obtain sensitive continuum maps that, in combination with our ALMA 1.3 mm data from cycle 3, will allow us to distinguish between the free-free emission and dust continuum regions in these sources. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2019-03-28T21:00:28.000 |
| 1400 | 2016.1.00761.S | 30 | Are Brown Dwarf disks in rho-Oph truncated? | Our successful systematic Cycle 1 survey for dusty disks around very low mass stars and brown dwarfs (VLMO) in rho-Oph has resulted in two very interesting results: the Mdisk/Mstar ratio appears lower than in more massive TTauri systems and the two brightest disks in the sample are consistent with small dusty disks with sharp edges. Are these the first direct observational hints of dynamical truncation of VLMO disks, predicted by some formation theories, or the effect of growth and segregation of large grains? We propose to answer this question by resolving the dust and gas distribution in a small sample of rho-Oph VLMO disks from our survey. Our observations will directly test dust and gas evolution models in VLMO disks and provide a first test of the dynamical interaction channel for VLMO formation. | Disks around low-mass stars | Disks and planet formation | 2018-09-05T16:07:13.000 |
| 1401 | 2017.1.00787.S | 20 | Physical Properties of Young Galaxies | Measuring the properties of young galaxies is central to understanding galaxy assembly and the reionization of the universe. We have spectroscopically confirmed many sub-L* galaxies at redshift 5.7. We propose ALMA [CII] observations that will measure their redshifts, thereby determining the offset of the Lyman-alpha emission line from the systemic redshift. Together, the Lyman-alpha and [CII] line properties will constrain the velocity and neutral column density of gas flows between these galaxies and their environment. By comparing the velocity offsets to those observed at cosmic noon (z ~ 2 - 3), we will gain important insight into the evolution of the neutral gas distribution and kinematics in galaxies. This information will strongly impact the interpretation of the rapid decline in Lyman-alpha emitting galaxies between redshifts 6 and 8, potentially slowing down the inferred progression of cosmic reionization. | Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies | Galaxy evolution | 2019-06-13T21:15:03.000 |
| 1402 | 2011.0.00064.S | 0 | Clustered Massive Galaxy Formation around a z=5.3 Submillimeter Galaxy | Cosmological simulations suggest that massive galaxies at present day form in the densest regions in the early universe, predicting the existence of massive protoclusters of intensely star-forming galaxies as their progenitors at high redshift. We have recently identified such a unique region within 1.1 billion years of the Big Bang, hosting an extreme starburst galaxy (the most distant submillimeter galaxy (SMG) identified to date, forming stars at 1800Msun/yr), and at least twelve normal star-forming galaxies (LBGs, the bulk are spectroscopically confirmed, and have 1-2 orders of magnitude lower SFRs than SMGs), within a narrow redshift interval of only dz=0.002. This most distant protocluster region known is a "smoking gun" for early massive galaxy formation through hierarchical buildup, giving key importance to understanding the physical properties of its member galaxies and the three-dimensional structure of the region in great detail. This proposal aims to add an essential missing piece to our comprehensive dataset on this proto-cluster by mapping out its core region in [CII] and rest-frame far-infrared continuum emission, using the ALMA early science array. This will critically constrain the neutral interstellar medium (ISM) content, excitation, distribution and kinematics of the central six LBGs (which, including the SMG, are situated within a single ALMA primary beam FWHM), constituting the fuel for their star formation, and dust-obscured star formation rates. This will also yield unprecedented constraints on the star formation law at z=5.3, and will enable the first direct ISM studies of LBGs at z>3. The [CII] measurements will give an order of magnitude more precise redshifts, substantially constraining the 3D structure of the protocluster. | Starburst galaxies, Galaxy groups and clusters | Active galaxies | 2013-08-06T15:41:00.000 |
| 1403 | 2017.1.00789.S | 60 | SN1987A: an evolving treasure trove of physics | SN 1987A provides an exceptional opportunity to observe the creation of a supernova remnant. ALMA provides unique information by probing both the cold molecular gas in the core of the ejecta through the emission of CO and SiO, and the synchrotron emission arising from the shocks and possibly a plerion. The high spatial and spectral resolution of ALMA provide a spectacular 3D view into the structures that were frozen into the ejecta at the time of the explosion. Therefore ALMA provides us with observations that directly test the energetics of the explosion, progenitor structure, and macroscopic mixing. We propose to follow up our cycle 3 observations to observe the evolution of the ejecta as the X-rays from the reverse shock propagate into the supernova. Over the 1000 day interval since our previous observations, ALMA can resolve the expansion of the ejecta at >2000km/s. Over the same time inverval the X-ray penetration of the ejecta has increased significantly, and the radioactive 44Ti heating has decreased. We shall also observe the ongoing destruction of the ring and seek evidence for a compact remnant. | Evolved stars - Chemistry | Stars and stellar evolution | 2018-12-22T19:59:06.000 |
| 1404 | 2021.1.01313.S | 55 | AGN in the SPT2349 protocluster at z=4.31 | We propose a search for AGN associated to galaxies in the most massive, highest SFR density protocluster known, SPT2349-59 at z=4.31. The AGN are likley to be dusty and while not unique identifiers sub-mm lines efficiently povide access to the entire AGN census. We will use deep ALMA observations of the protocluster in CO(14-13), CO(11-10) and CO(7-6) to provide high-J through mid-J CO lines for comprahensive SLED analysis of composite PDR+XDR models in combination with CO (4-3) and CO (2-1) data already avalible. The SPT2349 protocluster shows at least 12 sources with weak C+/FIR ratios, a possible signature of AGN-dominated emission, and many AGN are likely in the protocluster system. We will address what powers the bright ALMA protocluster sources, whether SMBH's are triggered by dense environments, and whether mergers trigger AGN and SF activity. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-08-22T07:30:58.000 |
| 1405 | 2019.1.01034.S | 45 | Resolved Molecular Gas in z~1 Star Forming Clumps | We propose to use the ALMA 12-m array to observe molecular gas and the dust continuum in resolved star forming clumps in 4, z~1 main sequence galaxies previously observed with the Keck/OSIRIS IFS. Studies of the resolved structure and kinematics of high-redshift (1 | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2021-03-10T19:15:35.000 |
| 1406 | 2017.1.01444.S | 28 | Studying the effects of variable UV heating on the outer disk | Here we propose to use ALMA to undertake the first variability study of UV sensitive lines in the millimeter in an object that is known to have substantial UV variability: GM Aur. We propose for a total of 1.5 hrs to observe the CN and HCN lines three times. If we detect variability, this would be the first observed link between UV emission and the heating of gas in the outer disk. This will complement our previous HST and near-infrared studies of GM Aur, where we studied the star-inner disk connection, by expanding this to the outer disk. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-08-24T13:15:32.000 |
| 1407 | 2019.1.01517.S | 104 | Gas around MS stars: A common exocometary origin for hot and cold gas | Non-negligible amount of gas has been found around main sequence AF-type debris disc stars by means of emission lines of CO, CI, CII, and OI. The origin of this cold gas located in the outskirts of < 20 debris disc systems is still under debate, but it is mainly attributed to collisions or evaporation of icy bodies such as planetesimals or exocomets. The report by our group of the presence of hot gas attributed to exocomet evaporation, and detected in optical wavelengths in the cold gas bearing debris disc systems with edge-on orientations points towards a possible common origin, and therefore a correlation. The presence of a scattering body (a.k.a. planet) provides a simple way of relating both gas components. We propose observations of CO (2-1) line of a sample of 8 stars with optical cometary absorption features to confirm a potential link between the inner exocomets and outer icy-planetesimals. | Debris disks | Disks and planet formation | 2021-03-20T13:33:48.000 |
| 1408 | 2016.1.01184.S | 57 | Accurate gas-to-dust ratios with [CI] at z~1 | Research in galaxy evolution aims to understand the cosmic industry of converting gas into stars. We have abundant photometric data to measure star formation rates and stellar mass evolution within galaxies and the Universe as a whole, but our understanding of gas mass evolution in the Universe must be improved to complete the picture and validate models. Almost all high-redshift gas measurements to date rely on CO as a tracer, but this is plagued by systematic uncertainties due to optically thick emission and poorly constrained dependences on gas density, distribution and metallicity. Recently some attention has been given to using dust as a gas tracer by assuming a constant gas/dust ratio, which shows promise for large samples but still requires accurate calibration on a direct gas tracer at high redshift. The [CI] line offers an opportunity to overcome much of the systematic uncertainty, yet observers have been slow to capitalise on this. We propose a survey of [CI] in a representative sample of star-forming galaxies at z~1 to measure accurate molecular gas and dust masses and provide a calibration that will be applicable to a wide variety of high-z star-forming galaxies. | Galaxy structure & evolution | Galaxy evolution | 2018-02-11T11:35:44.000 |
| 1409 | 2021.1.00960.S | 0 | Detecting extended [CI] emission in the 4C23.56 protocluster at z=2.5 | We propose deep Band 4 ACA observations of [CI](^3P_1-^3P_0) line toward a protocluster at z=2.5, 4C23.56, one of the well-studied protoclusters at z>2. We aim for confirming the existence and the distribution of extended cold and dense components in the circum-galactic medium (CGM), which is inferred from the currently available data sets of CO and [CI] lines that are detected at high resolution (<1"), in the protocluster. The proposed program will place a constraint on the `missing baryon' and in particular the fraction of the cold and dense gas in the CGM for the protocluster. This will eventually help us to understand the stellar growth of massive galaxies in the peak epoch of galaxy and cluster formation. | High-z Active Galactic Nuclei (AGN), Galaxy Clusters | Active galaxies | 2025-06-04T10:27:15.000 |
| 1410 | 2022.1.01753.S | 0 | First direct imaging of a dwarf planet's ring system | The dwarf planets represent a distinct class in the transneptunian population characterised by high densities, satellite systems, and a large variety of volatiles leading to complex surface chemistry. In this proposal we request ALMA band-7 observations to detect the thermal emission of the ring around the dwarf planet Haumea by direct imaging. The ring was recently discovered from occultation observations, the first one around a trans-Neptunian dwarf planet. Characterisation of the properties of the ring material will allow us to deduce whether it originates from collisional ejection or satellite disruption, and help to understand if ring systems can refresh ices on the surface of the main body, thereby explaining the high albedo of large trans-Neptunian objects. We will spatially resolve Haumea itself and determine its dimensions, directly imaging the triaxially-shaped, elongated dwarf planet at different rotational phases. We will be able to detect the spatially resolved thermal emission of the satellites, Hi'iaka and Namaka, crucial for the correct interpretation of system-integrated thermal emission measurements. Currently these goals can only be achieved by ALMA. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2025-02-27T17:08:54.000 |
| 1411 | 2017.1.00621.S | 111 | Search for host galaxies of metal absorption systems near the Epoch of Reionization | Metal absorption systems seen in high-z quasar spectra are a useful tool to study the ionization state and chemical enrichment of the inter/circumgalactic media and processes occurring within young galaxies near the epoch of reionization. However there are currently no observational identifications of galaxies associated with any metal absorption systems at z>4.5. We thus propose to obtain [CII]158um images for the fields of 20" (~100 pkpc) in radius centred on three quasars at z>6 to identify galaxies associated to metal absorption lines at 4.8 | Galaxy structure & evolution | Galaxy evolution | 2019-10-08T19:17:05.000 |
| 1412 | 2021.1.00105.S | 24 | The parsec scale view of the starburst ISM through molecular diagnostics | Extreme activities in starburst galaxies have a direct impact on their molecular interstellar medium (ISM). The effects on the ISM are most prominent in the vicinity of young stellar clusters on parsec-scales, dominated by feedback in the form of heating and outflows. The starburst galaxy NGC 253, thanks to its proximity and brightness, allows the most detailed ALMA studies of such starburst ISM properties. Sub/millimeter molecular lines are very powerful to probe the dust-obscured starburst and young clusters. We started in Cycle 6, and propose here to complete, a multi-line, multi-species survey in Bands 6 & 7 at ~0.2" resolution in the central 15" of NGC 253. Using a variety of molecular diagnostics, we will study the molecular cloud physical properties, the chemical composition caused by various heating sources, extreme excitation conditions, and cluster-scale outflows. Our study will efficiently reveal the highly excited physical conditions and signatures of feedback in the nearest starburst galaxy NGC 253. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2023-06-28T08:55:07.000 |
| 1413 | 2015.1.01047.S | 16 | Resolving the HCN Enhanced Nuclei in Nearby Seyferts: HCN Masers or Dense Molecular Outflows? | We aim to image the HCN(1-0) distribution and kinematics, together with the HCO+(1-0) and HNC(1-0) lines, toward the HCN enhanced nuclei of nearby Seyfert galaxies, NGC 1097, NGC 3227, and NGC 5033. These galaxies show strongly enhanced HCN(1-0) emission toward their Seyfert nuclei, suggesting the effect of AGN activities to the surrounding molecular gas. Indeed, one of the HCN enhanced nucleus galaxy M51 shows AGN-driven molecular outflows and a HCN maser toward the nucleus, suggesting that other galaxies also have similar phenomena in their nuclei. We look for the evidences of AGN-driven outflows, HCN masers, and/or AGN radiation effect using HCN(1-0), HCO+(1-0), and HNC(1-0) lines, which can be observed simultaneously. With these observations, we will study what drives the molecular outflows from AGNs (jet vs radiation), whether the nuclear disk exists or not, and/or what is the effect of strong AGN radiation to the surrounding molecular gas. Since there are very few studies of spatially and kinematically resolved circumnuclear molecular gas, this study will provide a solid understanding of AGN feedback mechanism. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-03-18T13:07:52.000 |
| 1414 | 2022.1.00236.S | 750 | Exploring the sulphur content of Class I protostars | Sulphur-bearing molecules may have played an important role in the origins of life on Earth, however, the sulphur chemistry is poorly understood in the process of low-mass star and planet formation. Dense cores are depleted in S-bearing species, while deeply embedded protostars and cometary samples show different abundances of S-molecules. We lack information about the evolution of the sulphur chemistry along the different stages of star and planet formation and, in particular, about the sulphur content of Class I sources and its potential contribution to late accretion and planet formation. We propose to survey a sample of 30 Class I sources located in three different star-forming regions. The ACA configuration and a single Band 7 spectral correlator setup will be used to observe the most simple S-bearing molecules, achieving an angular resolution of ~3.5". Our goal is to investigate whether the most common and simple S-bearing species are present in Class I sources and, if so, to determine how bright they are and compare abundance ratios with other stages of star formation. This survey will contribute considerably to our knowledge of the sulphur content in young protostars. | Low-mass star formation | ISM and star formation | 2024-06-23T17:03:11.000 |
| 1415 | 2016.1.00017.S | 5 | First Mapping of the B-fields in the Protostellar Jets Near the Launching Point | Protostellar jets are believed to be the key to removing excess angular momenta from accretion disks, allowing material to fall onto the protostars during the star formation. In current jet launching models, magnetic fields (B-fields) are required to launch and collimate the jets, and thus expected to be helical in the jets. Our previous attempt to map the B-fields in the brightest jet in SiO with the Submillimeter Array has shown a tentative detection of polarization in the outer part that could be due to helical B-fields. With ALMA, we propose to zoom in and map the B-fields in the inner part of the jet near the launching point (within ~ 560 AU of the source) in SiO at higher angular resolution with unprecedented signal to noise ratio. By measuring the pitch angle and the strength of the B-fields, we aim to determine how efficient the B-fields can accelerate and collimate the jets, setting the first constraint on the role of the B-fields in the jet launching models. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-01-25T13:22:36.000 |
| 1416 | 2023.1.00432.S | 0 | Sub-kpc mapping of dense gas in high-z star-forming galaxies | Dense gas is the key to star formation. However, very little is known about the dense-gas content of galaxies at z>1, as the HCN, HCO+, and HNC lines which trace the dense gas are often >1 dex fainter than the CO or [CII] emission. Recent spatially unresolved observations indicate that despite their enormous star-forming rates, high-z galaxies contain relatively little dense gas but convert it into stars efficiently. Still, to properly quantify the star-forming efficiencies in them, we need to map their dense gas on sub-galactic scales. We request 36 hours of 0.3" imaging of the HCN, HCO+, HNC(4-3), and CO(3-2) emission on ~500-pc scales in three strongly lensed z~3 galaxies - an on-going merger, a post-coalescence merger, and an isolated disk. We will: (1) map the star formation, molecular and dense gas across 10+ resolution elements in each galaxy; (2) use the HCN/HCO+/HNC/CO ratios to characterise the physical conditions of the dense-gas phase; (3) pinpoint potential compact obscured nuclei. Together, this project will provide the first high-resolution view of these key ingredients of star formation in high-z, intensely star-forming galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-11-21T11:37:37.000 |
| 1417 | 2013.A.00023.S | 6 | Follow up of possible Galactic Supernova in the disk | A search of the VVV 1st Data Release led to the discovery of WIT-01, a very high amplitude variable with unusual colors from amongst 50 million sources (Minniti et al. 2012, ATel 4041). WIT-01 is very red: H−Ks=5.2 mag, and invisible in the Z, Y and J passbands. The very rapid decline in flux by >8 magnitudes plus the very red colors are unprecedented, and inconsistent with known examples of variable stars. Therefore, we postulated that this object would have to be the prototype of a new sub-class of PMS variable, or alternatively, a highly extincted supernova in the Milky Way (Av~100 mag), detected at some time after maximum light. We submitted an ALMA proposal in 2012 to test these possibilities, and now that the observations are finally concluded, we detect a new source in the field. There was no detection in band 3 in 2013 and 2014, but there is now in August 2015 a new source very close to the hypothetical SN and with the right predicted flux. However, there are still some doubts about the position, and we hereby request 3.2 hours of ALMA time in total to confirm this detection before announcing this exciting discovery. | Supernovae (SN) ejecta | Stars and stellar evolution | 2016-05-10T00:00:00.000 |
| 1418 | 2017.1.01045.S | 18 | Resolving molecular gas to ~500 pc in a unique star forming disk galaxy at z~2 | For the first time ever, we will resolve molecular gas in a 'typical' star forming disk galaxy at z>2 down to the scale of ~500 pc. The target, BX610, is a massive disk galaxy with large gas reserves which, unlike many galaxies studied at high redshift, is undergoing modest quiescent star formation, likely through cold mode accretion. This galaxy therefore represents an under-studied, but cosmologically important population in the early universe. We have already carried out observations on larger spatial scales to determine bulk molecular and atomic gas properties with CO(7-6), CO(4-3), [CI] (2-1), and [CI] (1-0), and now we intend to probe CO(4-3) emission to unprecedented resolutions. These observations enable an unprecedented view of the obscured star formation that is hidden to optical/UV imaging. We will trace out the bulk of the molecular gas fueling star formation on a fine enough scale to resolve morphological traits and provide a view akin to single dish surveys in the local universe. Furthermore, this will provide a test of the star formation rate surface density scaling law in a never-before-investigated regime. | Damped Lyman Alpha (DLA) systems | Cosmology | 2019-03-26T14:31:10.000 |
| 1419 | 2015.1.01512.S | 43 | Has Planet Formation Already Begun in the Class I Protostellar Phase? | Recent ALMA observations of the early Class II protostar HL Tau revealed gap structures indicative of newly-forming planets. The observations represent the earliest direct detection of planet formation, suggesting that planets form during the first million years of star formation. These observations showed that planets form before some theoretical predictions, which begs the simple question: "When exactly do planets start to form?" While it is known that planets should start their formation in a Keplerian disk, we do not know if they start forming at times significantly younger than HL Tau. To further constrain whether gap structure appears at an early stage, i.e., the Class I stage, we propose for high angular resolution (0.035" = 4.4 AU) toward the Keplerian disk IRS 63 located in Ophiuchus. This source is one of the brightest known Class I disks and has a small inclination of only 30 degrees. These observations will easily detect gap structure if it exists in younger sources. Such observations will either reveal the earliest known direct evidence of planet formation or put significant constraints on the age of which planets start to clear out material in protostellar disks. | Disks around low-mass stars | Disks and planet formation | 2018-01-04T14:38:00.000 |
| 1420 | 2013.1.01241.S | 5 | Detecting [CII] in two strongly lensed z~6 star-forming galaxies | We propose to conduct deep ALMA observation of two z∼6 sub-L∗ star-forming galaxies to detect their [CII] emission line and derive from the line flux their star formation activity. These two Lyman-break galaxies are unique multiple image systems found in the massive cluster lenses Abell 383 and MS0451-03 at redshift 6.027 and 6.703 respectively. Their lensing magnification is ~11 and 100 respectively thus allowing to probe the properties of "normal" low luminosity galaxies at early times in the Universe. The proposed observation will lead to a secure [CII] detection. However, would we not detect [CII] the upper limit we can derived will have strong consequences on our understanding of star formation in the early Universe advocating for unexpected strong evolution in the galaxy formation models. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2016-03-20T13:14:16.000 |
| 1421 | 2023.1.00098.S | 0 | Constraining the stellar mass-loss-rate evolution on the AGB (and slightly beyond) | It is believed that stellar mass loss increases as the star evolves along the AGB, and that it is higher the more massive the star is. However, there is little evidence that supports these beliefs. These are troublesome lacks of understanding since the mass-loss evolution of AGB stars is an important input parameter in population synthesis and galactic chemical evolution models, in which the mass-loss rates of AGB stars follow prescriptions based on the above expectations. It is therefore of great importance to empirically determine the mass-loss rate evolution for a large sample of AGB stars to improve the prescriptions. Of particular interest is the upper AGB and the early post-AGB where most of the stellar mass is expected to be lost. With this proposal, we aim to observe an equidistant and complete sample of the most extreme AGB stars in the inner Galactic Bulge in circumstellar CO lines. We will constrain their phase of strongest mass loss, and the sharp decline in mass loss expected to take place at the end of the AGB. This study will provide a much-needed and unprecedented empirical picture of the evolution of AGB gaseous mass loss at its most extreme phases. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2025-07-26T19:39:37.000 |
| 1422 | 2015.1.01177.S | 7 | Twins at heart? The centre of M83 as a Milky Way analogue | Detailed studies of the inner few 100 pc of the Millky Way are revolutionising our understanding of SF in extreme environments and feeding/feedback cycles in galactic nuclei. However, future developments are limited by the fact that we lie in the disc of our Galaxy, making it difficult to unambiguously determine the 3D geometry of gas and stars, and that the Galactic centre only provides a single snapshot of an evolutionary cycle. We seek to exploit M83's remarkable similarity with the Milky Way to overcome these limitations. ALMA observations will uniquely allow us to derive the density and pressure evolution of gas falling into the nucleus of M83 and determine (i) the dominant physical mechanisms regulating the mass flows and energy cycles down to the sizescales of individual clouds, and (ii) whether the star-forming clouds and stellar clusters follow an evolutionary time-sequence, which has been hypothesised to result from a tidal compression that triggers collapse. | Starbursts, star formation, Galactic centres/nuclei | Active galaxies | 2017-07-25T19:40:21.000 |
| 1423 | 2019.2.00120.S | 2126 | The Nearby Evolved Stars Survey: quantifying the gas and dust return to the Galactic interstellar medium | Outflows of asymptotic giant branch and red supergiant stars drive local galactic chemical evolution. The Nearby Evolved Stars Survey (NESS) is a global project targeting a volume-limited sample of evolved stars within 2 kpc to constrain the physics driving mass loss. NESS includes ongoing JCMT (515 hr) and APEX (56 hr) surveys to observe CO(2-1), CO(3-2) and dust continuum from ~500 sources, and at the Nobeyama observatory (190 hr) for CO(1-0). We propose 12CO and 13CO(2-1) and (3-2) observations of the 280 NESS sources visible to the ACA that do not have archival data (total sample 301 sources). Combining the high resolution and large field-of-view of the ACA with data from the JCMT and APEX, we will thoroughly probe their inner shells, revealing the mass-loss history, geometry and the 12C/13C and dust-to-gas ratios. The large, volume-limited sample will robustly constrain the onset of mass-loss variations and asymmetry. All NESS data, including reduced data, catalogues, codes and model results will be publicly available. The NESS database is poised to become the authoritative source for evolved-star studies in the next decade, and the proposed ACA data will be a vital addition. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2022-10-12T14:11:22.000 |
| 1424 | 2019.A.00041.T | 12 | GRB 210905A at z = 6.318: Tracking the Farthest Cosmic Explosion Seen by ALMA | This is an urgent ToO proposal for ALMA follow-up of the recent z=6.318 gamma-ray burst GRB 210905A. We have detected the mm and cm afterglow of this rare (once in 7 years) high-redshift (z>6) GRB with ALMA and ATCA, and expect it to be detectable only for another ~ 10 days. GRB 210905A is only the second high-z GRB ever with a mm afterglow, and the first high-z GRB detected with ALMA. Being associated with the deaths of massive stars, GRBs are excellent probes of star formation in the high-redshift Universe. Radio/mm observations of GRB afterglows are essential for quantifying the energy release, measuring the circumburst density, and constraining ejecta collimation. In turn, these quantities inform our understanding of processes ranging from stellar feedback to the origin of cosmic magnetic fields. However, high-z GRBs are extremely rare, and radio/mm detections are rarer still: 7 z>6 events are known, 4 of which have been detected in the cm-band and 1 in the mm-band. We request continued ALMA follow-up at ~ 7d & 15d after the burst. We will support these ALMA data with approved ATCA observations, extensive near-IR follow-up (VISTA), and X-ray monitoring (Swift, Chandra). | Gamma Ray Bursts (GRB) | Cosmology | 2022-03-15T14:43:36.000 |
| 1425 | 2017.1.00561.S | 21 | The Fomalhaut C Debris Disk: Key to the famous eccentric ring around A? | The A-type star Fomalhaut is the primary component of a compelling and well studied extra-Solar stellar and planetary system; host to an eccentric planet (Fom b) and two distant low-mass companions (Fom B & C). Fom A hosts a spectacular eccentric debris ring. Our discovery of an unresolved disk around Fom C with Herschel prompted us to propose a "unified" stellar capture scenario that explains the origin of the wide triple star system and the eccentricity of the debris ring around Fom A, without invoking unseen planets. A key prediction of this scenario is that the debris disk around Fom C should be asymmetric and warped. We have obtained an HST dust-scattered light image of the Fom C disk that indeed shows a strong asymmetry, so supports our stellar capture scenario. The HST image suffers from high-contrast imaging artifacts and is only sensitive to small dust, issues which are avoided by ALMA imaging. We propose to image the Fom C disk structure with 3.2h of ALMA band 7 time to shed light on the origin of the Fomalhaut system, with wider application to the origin of wide stellar systems, whose origins are rarely tested. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2019-06-27T16:12:24.000 |
| 1426 | 2011.0.00005.E | 0 | HL Tau Band 9 B2B | ALMA engineering data release. | 2018-07-10T12:50:54.000 | ||
| 1427 | 2016.1.00940.S | 17 | 3D Positions, Velocities, and Accelerations of SiO Masers in the Inner Parsec | We propose to measure precise positions and velocities of circumstellar SiO masers close to the Galactic central black hole (Sgr A*). Position and velocity tracking of maser-emitting stars within 1~pc of Sgr A* will provide three-dimensional positions, velocities, and accelerations, enabling precise mass measurements at a variety of radii. One can therefore probe the stellar mass distribution in the inner parsec, provide a reference frame for near-IR observations of stars directly orbiting Sgr A*, and enable multiple direct probes of the black hole metric. 3D tracking of stars close to Sgr A* can test the equivalence principle, the ``no-hair'' theorem of black holes, and frame-dragging, but only if star-star scattering is not too large, which the proposed observations can address by precisely measuring the stellar potential at many different radii. The proposed observations will be combined with previous VLA and ALMA observations and will yield errors on position of roughly 2 milliarcseconds, errors on Doppler shifts of ~8 m/s, and errors on accelerations of ~5 m/s/yr. We require only 26 minutes of on-source integration (1.2 hours total). | Galactic centres/nuclei | Active galaxies | 2018-11-24T19:11:02.000 |
| 1428 | 2016.1.01543.S | 12 | The Chlorinity and Chemical Composition of Europa's Subsurface Ocean | Europa, an icy world orbiting Jupiter, is one of the most promising places for harboring life in the outer solar system. A global subsurface ocean was inferred to exist inside Europa from the diversity of surface geological features and the magnetic field measurements made by the Galileo spacecraft. In addition, detections of the atomic O and H emission by HST also suggested water vapors outgassing from Europas south polar region, similar to Enceladus plume activities. As the first step in understanding the potential of Europa being an abode for life, we propose to use ALMA to study the chlorinity and chemical composition of Europa's subsurface ocean, targeting the molecular species of NaCl, KCl and H2O in the atmosphere. Our proposed work will provide crucial information of Europa's outgassing events, the sources of Europas atmospheric species and their associated radiolytic effects (irradiated vs. prior-to-irradiated) as they can provide better constraints in the ocean chemistry models such as the salinity and the oxidation state. It will also contribute to future space missions, such as NASAs next flagship mission to Europa and ESA's JUICE mission. | Solar system - Planetary atmospheres, Solar system - Planetary surfaces | Solar system | 2018-06-27T03:54:35.000 |
| 1429 | 2019.1.01484.T | 190 | Gamma-ray Burst Physics with ALMA: Direct Implications for the Explosions and Progenitors | Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, and thus serve as unique laboratories for high-energy astrophysics and compact-object formation, as well as premier probes of the high-redshift universe. Observations of GRB "afterglows" provide critical insight into the energy scale and local environment of the bursts, thereby elucidating the explosion mechanism and nature of the progenitors. However, the existing extensive optical/X-ray afterglow data alone are degenerate with respect to these GRB properties. Millimeter and centimeter observations are critical for breaking these degeneracies, but pre-ALMA GRB follow-up has yielded a mm-band detection rate of <5%. We have begun to remedy the dearth of mm-band detections through our ALMA Cycle 4 & 6 programs, which were successful in detecting and characterizing mm emission from 3 GRBs. Following on this success, we now propose a mm-band survey comprising ALMA ToO observations of 4 GRBs to begin to address key unsolved questions. We will support these ALMA data with JVLA, ATCA, and GMRT observations, extensive optical follow-up (Gemini, Magellan, MMT, Keck), and X-ray monitoring (Swift, Chandra, XMM). | Gamma Ray Bursts (GRB) | Cosmology | 2022-06-17T16:38:51.000 |
| 1430 | 2021.1.00272.S | 21 | Small but mighty: Reconciling a paradoxical low-mass, ultra-dusty galaxy at z=4.27 | The existence of dust in the early Universe and in low mass galaxies challenges our understanding of how metals are built up over cosmic time. We propose to exploit a strongly-lensed galaxy from the Frontier Fields at z=4.27 whose stellar mass is a mere 4e9Msun but where the majority of the star formation is obscured by dust. With an existing [CII] detection, this galaxy provides the ideal laboratory to explore primitive interstellar medium conditions, and put first constraints on the metallicity. Specifically, we propose to (1) quantify the ionized gas with [NII]205 and determine the neutral fraction of [CII], (2) measure the CO(4-3) luminosity and combine with [CII], [NII] and LIR to constrain the radiation field and gas density, and (3) use the 600 micron rest continuum emission to establish the total dust mass. Together these observations will clarify the unusual conditions that led to a low-mass, ultra-dusty galaxy only 1.4 billion years after the Big Bang. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2023-01-05T08:31:34.000 |
| 1431 | 2017.A.00035.S | 17 | Using eclipses to determine the size of a neutron star jet | We recently made ALMA observations of a neutron star low-mass X-ray binary system, 3FGL J0427.9-6704, with the aim of detecting an eclipse of the mm emission from the jets. The source shows optical, X-ray, and gamma-ray eclipses, from which the donor star radius and orbital separation have been determined. This motivated our recent ALMA study to determine whether the mm emission was also eclipsed, and if so for how long. Our Band 6 observations showed a drop in flux density over the period of the eclipse that was not seen at Band 3. However, the low flux density and the stochastic variability of the source mean that this conclusion remains tentative. We therefore request a single 90-minute ALMA Band 6 DDT observation to confirm these intriguing recent results, and provide the first direct probe of the size scale and launching radius of jets from a neutron star. | Pulsars and neutron stars | Stars and stellar evolution | 2018-11-28T06:32:39.000 |
| 1432 | 2019.1.00894.S | 8 | Molecular observations of the AGN Torus in Cygnus A | We propose path-finder observations to detect CO emission from the archetype powerful radio galaxy, Cygnus A. The immediate goal is to make a first measurement of the CO luminosity of the recently discovered 'torus' region. Cygnus A, at a redshift of 0.0564, provides a unique laboratory to study the detailed physical processes in high (quasar-like), luminosity AGN right in our own backyard! We have discovered a structure in the nucleus of Cygnus A which may be free-free emission from the long-sought circumnuclear torus. The key to understanding this structure is to image the molecular gas and dust in the multi-phase, obscuring torus. Unfortunately, to date, no detection has been made of molecular emission from Cygnus A, although the existing limits are poor. In our path-finder observations, we will perform a search for CO emission at a resolution adequate to isolate the toroidal region, but not over-resolve any potential emission. These results will be used to plan high resolution imaging of the torus, to determine the dynamics and physical conditions in this unique AGN laboratory. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-09-01T22:41:01.000 |
| 1433 | 2018.A.00021.S | 53 | Confirmation of an Embedded Planet in the Disk of TW Hya | Detecting planets during their formation is essential if we are to directly confront planet formation theories. Large programs dedicated to characterizing the substructure in protoplanetary disks have failed to detect any evidence of circumplanetary disks. Similarly, searches in the near infrared are hindered by the large opacities of dust which can hide any embedded planets. We have compelling kinematical evidence for a 2 Neptune mass planet at 75au and a position angle of 120 degrees in the disk of TW Hya. Using archival 12CO data we detect a large spiral in the gas velocities, two spirals in the temperature of the gas and a tentative region of enhanced velocity dispersion coincident with the end of the kinematical spiral. We request DDT observations for Band 6 data of comparable angular resolution and sensitivity to confirm with independent tracers (CO and CS) the presence and location of this embedded planet. While an expensive project, this will provide a clear case-study of ALMA's planet-hunting capabilities and demonstrate that such observations are the future of planet detection. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2020-10-25T00:00:00.000 |
| 1434 | 2018.1.01302.S | 7 | Understanding the 3D structure of the disk around LkHa330 | Circumstellar disks around young stars are the birthsites of planets. In the past few years, recent images of transition disks have revealed dust depleted inner cavities with asymmetric structures (spiral arms, dips, etc). An exciting explanation for these features is that they are the results of interaction of the disk with embedded planets. Our recent scattered light observations of the young transition disk around LkHa330 shows the presence of two asymmetric features that resemble spiral arms. Previous millimeter observations detected a cavity and a lopsided structure around the object, albeit at low angular resolution (0.35"), which prevents a direct comparison between the two types of observations. In this program, we propose to observe at high angular resolution in Band 6, the young transition disk around LkHa330 to detect millimeter counterparts to the features detected in scattered light. The combination of gas tracers, small dust (traced with scattered light image) and large dust grains (traced with ALMA) will allow to constrain the 3D structure of the disk, and understand the nature of the detected features. | Disks around low-mass stars | Disks and planet formation | 2021-08-31T00:00:00.000 |
| 1435 | 2017.1.00006.S | 22 | The detached shells around DR Ser, V644 Sco, and S Sct | We propose to observe the detached shells around the carbon AGB stars DR Ser, V644 Sco, and S Sct in CO(1-0). The shells were created during the high mass-loss rate phase of a thermal pulse (TP). The observations will allow us to determine the evolution of the mass loss from AGB stars during and after a thermal pulse. The amount of mass lost during the TP cycle is critical, as it limits the number of TPs an AGB star experiences, and hence the yields to the ISM. We will observe the shells and the extended circumstellar envelopes at a spatial resolution of 1"-1.5". The shells span the entire age range of known detached shell sources, allowing us to constrain the mass-loss rate shortly after the thermal pulse, and to follow the evolution of the shells until they get photodissociated after 10000 years. The proposed observations will yield the most detailed view of the evolution of the mass loss throughout the TP cycle on the AGB, and will constrain critical aspects of late stellar evolution. The results will move current research beyond the state of the art in understanding the chemical evolution of stars, the ISM, and galaxies. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2019-11-29T10:45:33.000 |
| 1436 | 2011.0.00028.S | 0 | The Effect of Extreme Environment on Protoplanetary Disks in Orion | Protoplanetary disks, or "proplyds" are the sites where new Solar systems are born. While disk studies to date have focused on regions like Taurus and Ophiuchus for their proximity, stars rarely form in such isolated environments. In fact, there is clear evidence that our own Sun formed near a clustered OB association like Orion. To understand how planets form it is imperative that we study disk properties in regions representative of their origins. For this reason, we propose to survey 41 protoplanetary disks ("proplyds") in Orion in order to study fundamental disk properties in a massive star forming region. ALMA is uniquely capable of imaging dust and gas emission from the Orion proplyds with its combination of high frequency, sensitivity, resolution and spatial filtering properties. We will measure the masses and survival timescales of numerous disks, we will spatially resolve the dust emission to determine surface density profiles of the largest disks in the region, and we will attempt to detect molecular gas in Orion disks for the first time. The results of such observations will provide the first detailed view into how the clustered environment and UV radiation affect disk properties and evolution, and ultimately, allow us to assess the potential to form Solar system analogs in massive star forming regions. | Disks around low-mass stars, Low-mass star formation | Disks and planet formation | 2014-01-03T18:04:00.000 |
| 1437 | 2022.1.01608.S | 73 | Mapping molecular gas exposed to strong X-rays, cosmic-rays and shocks of the supernova remnant | Supernova (SN) feedback plays a key role in regulating galaxy evolution and star forming rate. Despite ample theoretical studies of SN feedback, it still lacks observational constraints on how SN energy is transferred to the ISM through different feedback channels such as X-rays, cosmic rays (CRs), and shocks. As the most luminous Galactic supernova remnant (SNR) in the X-ray band and energetic CR accelerator, W49B is an ideal laboratory to study SN feedback in detail. Recently, HCO+ emission and HCO+/CO have been proposed as a potentially useful probe of multi-channel feedback of SNRs onto molecular clouds (MCs). We propose ALMA HCO+ 1-0 and 3-2, and CO 3-2 observations toward W49B, aiming 1) to unveil how MC properties are controlled by X-rays, CRs, and shocks, and 2) to quantify the SNR energy transferred to the MCs. This observation will also provide crucial insight into the molecular heating and chemistry near extragalactic high-energy sources. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2023-10-28T15:07:27.000 |
| 1438 | 2015.1.01235.S | 35 | The core mass function in a far-outer Galaxy cloud | The distribution over mass of stars at birth, the initial mass function (IMF) is one of the most important parameters in star-formation research. It is still not clear what determines the IMF, nor whether the IMF is the same for every star forming region. It does seem, however, that the IMF is set very early on by the masses of the molecular cores out of which the stars form. The core mass function (CMF), and by consequence the IMF, may however depend on the physical and chemical properties of the environment. So far, CMFs (and, with few exceptions, IMFs) have been determined in molecular clouds (and star clusters) in the solar neighbourhood and the inner Galaxy. We propose to determine the CMF in a molecular cloud in the far-outer reaches of our Galaxy (galactocentric distance 16 kpc), where conditions are very different from the inner Galaxy. We do this by continuum and line observations of 94 clumps identified from Herschel 250 micron images of this cloud; each clump is assumed to contain one or more cores, of sizes comparable to the ALMA beam. We aim to be able to detect cores with masses of the order of the Jeans mass (1 Msun). | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-07-21T15:18:32.000 |
| 1439 | 2021.1.00363.S | 4 | Star Formation in the Brick & Cloud C: Combining JWST with ALMA | The Brick, G0.253+0.015, is the densest, most massive infrared dark cloud in the Galaxy. It appears to be highly deficient in star formation, yet the entire cloud mass exists above star-formation thresholds measured in local clouds. With a gravitationally bound mass of ~10^5 Msun, this cloud is likely to form a high-mass cluster, but we see it now at an early, pre-stellar stage. However, open questions remain: has this cloud been forming low-mass stars, below our detection threshold? If it were forming a population of low-mass YSOs, like those seen in local clouds (e.g., the Taurus molecular cloud), they would not yet have been seen. What suppresses star formation in this cloud? These questions have motivated two JWST programs mapping this cloud and its neighbor, Cloud C, to search for low-mass YSOs and measure the density structure of the cloud. We propose to obtain ALMA observations that will match JWST's spatial resolution, obtain comparable sensitivity to Class II objects, and obtain superior sensitivity to deeply-embedded Class 0/I objects. Combining JWST with ALMA data, we will assemble a complete view of these clouds' recent and ongoing star formation activity. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-09-21T23:21:14.000 |
| 1440 | 2015.1.01151.S | 45 | The first glimpse of CO 2-1 in z=1.6 cluster galaxies | We propose Band 3 observations for a stellar mass-limited sample of spectroscopically-confirmed cluster galaxies to detect CO(2-1) for the first time within z=1.6 massive cluster environments. CO(2-1) traces the total molecular gas reservoir that fuels star formation (SF), allowing us to place the first constraints on the evolution of the gas fraction within the highest density regions at z=1.6. This epoch marks the peak in the integrated SF of the Universe, and the pivotal point when SF migrates to cluster cores. Comparing CO within cluster galaxies to the field at z~1.5 will help us address the crucial question: what governs SF over cosmic time and in various environments? We target 3 massive spectroscopically-confirmed clusters (70 members) from the SpARCS survey, which has so far returned ~20 high-z clusters. With a minimum of 18-24 detections, we expect to more than triple the current sample of CO measurements in cluster environments in 13.3 hours total. All 3 clusters also have Cycle 21 HST time (16 orbits) for additional spectroscopy and imaging. This redshift represents the most distant epoch at which it is possible detect the CO(2-1) transition with Cycle 3. | Galaxy Clusters | Cosmology | 2017-06-27T18:14:29.000 |
| 1441 | 2022.1.00313.S | 0 | Planet formation in AB Aur | In order to look for planets at earlier evolutionary stages, indirect evidences are invoked, such as rings of dust-free regions within dense disks, or spiral patterns. In the previous study of the molecular spirals (0.14", 12CO 2-1) within the AB Aur dust cavity, the existence of an embedded object at a radius of 30 au (P1) and an additional object at a radius larger than 90 au (P2) have been suggested. At P1, two evidences of embedded object have been detected: 1) recent SPHERE/VLT image at near infrared (NIR) reveals a twist feature; 2) ALMA reveals CO bright clump in several velocity channels deviating from Keplerian rotation. At P2, a clump-like protoplanet has been newly reported at NIR continuum with Halpha emission. Using Band 6, we propose to simultaneously measure the gas content in the spirals by a high sensitivity, high resolution search for 12CO, 13CO and C18O 2-1 in these spirals, and to test the possible existences of Circum-Planetary Disks (CPDs) at P1 and P2 both kinematically, using 12CO 2-1, and in continuum taking advantage of the high resolution (0.04"-0.06") and sensitivity to dust (9 microJy/beam). | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2024-11-21T00:58:03.000 |
| 1442 | 2022.1.01163.S | 27 | Simultaneous Monitoring of Stellar Flares with ALMA and TESS to Discover Space Weather Environments of Exoplanets | The high energy emission from stellar flares calls into question the habitability of planets orbiting M-dwarf flare stars. While the recently-discovered population of millimeter flares closely traces this high energy emission, the relationship to the optical wavelengths at which flares are usually observed remains unclear. Here, we propose the first ALMA observations of M-dwarf flares alongside simultaneous optical monitoring at 20 sec cadence with TESS. The multi-wavelength observations will determine for the first time (1) if higher rates of millimeter flaring than optical flaring are typical of M-dwarf flare stars, informing the space weather environments of terrestrial planets. (2) The proposed observations will also quantify the degree of optical decoupling to millimeter flares for a select handful of large events observed simultaneously in both wavelengths. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2024-03-09T18:44:28.000 |
| 1443 | 2016.1.00455.S | 82 | A CO Survey toward the Host Galaxies of Long-duration Gamma-ray Bursts | Long-duration gamma-ray bursts (GRBs) are though to be associated with the explosions of massive stars, and are expected to be a new tool to probe star-forming activity in the distant universe. To establish the link between GRBs and star formation, it is necessary to understand the properties of GRB hosts in terms of molecular gas. Previous studies suggest a higher star-forming efficiency (SFE) and shorter gas depletion timescale in GRB hosts compared to local and z ~ 1-2 star-forming galaxies. However, the sample size is limited (only three hosts with CO detection). In addition, there is an uncertainty on molecular gas mass from the assumed CO-H2 conversion factor, especially for low-metallicity hosts. We propose CO and dust continuum observations toward 6 GRB hosts. We select targets with metallicity higher than the solar value, which reduces the uncertainty of conversion factor, offering the best sample for molecular gas study. Our goal is to examine whether GRB can be used as an unbiased tracer of star formation. We study the properties of GRB hosts (molecular gas mass and SFE, gas depletion timescale, and obscured star formation) by comparing with other star-forming galaxies. | Gamma Ray Bursts (GRB) | Cosmology | 2018-04-24T05:57:40.000 |
| 1444 | 2016.1.00805.S | 12 | Origin and variability of the (sub-)mm continuum emission in the changing-look AGN Mrk590 | The dramatic disappearance of the optical broad emission lines in Mrk 590 between the years 2006 and 2012, along with the concurrent fading of its radio to X-ray continuum fluxes, suggest that the AGN was turning off. Studying such extreme behavior in these rare changing-look AGNs can provide profound insight into black hole fueling, accretion and energetics. The goal of our highly ranked Cycle 3 proposal was to measure the (sub-)mm fluxes of Mrk 590 during its low accretion state, providing a crucial reference for variability studies should the AGN reignite. Recent Swift observations show the X-ray fluxes steadily increasing in strength, as expected if the AGN is turning on again! This is an unprecedented opportunity to witness this rare event as it occurs. We request continuum flux measurements at 110, 343, 470, and 670 GHz in Cycle 4, to compare with our Cycle 3 fluxes and determine if they are also strengthening. This will be the first study of (sub-)mm flux variability in a changing-look AGN, to investigate the origin of the (sub-)mm continuum emission, its spatial extent and its energetics relative to nuclear components emitting at other wavelengths. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-11-21T12:40:55.000 |
| 1445 | 2023.1.01504.S | 0 | Neptune's High-Altitude Wind Chill from ALMA | We know much less about the atmosphere of Neptune, and the other ice giant planet Uranus, compared to other planets like Earth and Jupiter. Processes such as convection can generate storms and affect a planets upper atmosphere that is also strongly influenced by its seasons, which for Neptune last 40 years. Therefore, studying the motion and structure of a planet's upper atmosphere investigates the relative strength of effects operating over various timescales and across large distances between different planetary region. We propose to study the dynamics of Neptune's stratosphere, where the competition between seasonal effects and processes such as convection can affect different large-scale circulation patterns present in the atmospheres of Earth, Jupiter, and even exoplanets. The ice giants are considered an analogue for a large fraction of exoplanets discovered and ALMA's spectral and spatial resolution make it well-suited to study Neptune. | Solar system - Planetary atmospheres | Solar system | 2025-07-22T21:04:04.000 |
| 1446 | 2011.0.00108.S | 0 | X-ray irradiated dense molecular medium in the active nucleus of NGC 1097 | We propose to study the physical and chemical properties of dense molecular gas in the central kpc region of the nearby active galaxy NGC 1097 at 110 pc (1".6) resolution. NGC 1097 hosts a type-1 Seyfert nucleus with a circumnuclear starburst ring with a radius of 10". Furthermore, the nuclear molecular gas condensation exhibits unusually elevated HCN/HCO+ brightness ratios in both J=1-0 and 3-2 transitions and CO(2-1)/CO(1-0) ratios, which are never seen in starburst galaxies. Therefore, NGC 1097 is one of the best showcases demonstrating the physical and chemical diversity of the dense molecular medium as a function of heating sources, i.e., AGN and starburst in ~100 pc resolution even in cycle 0 ALMA. We have selected a set of key dense molecular tracers to describe physical and chemical aspects of AGN and starbursts, i.e., HCN, HCO+ , CS, and SiO, which can be efficiently observed in Band 3 and 7, thanks to the superb spectroscopic capability of ALMA. With these measurements, we will address the following issues: (1) abundance ratio variations of HCN, HCO+, and CS: Is the elevated HCN/HCO+ ratio caused by X-ray irradiated dense molecular medium? (2) detecting the SiO emission in the active nucleus: Is the central dense gas condensation a XDR like NGC 1068? (3) search for vibrationally excited HCN emission: what is the role of radiative pumping in the 100 pc region around AGN? (4) kinematics of dense clouds: can we see the inflow of dense clouds to the nucleus, or outward motion driven by a putative jet/outflow from the nucleus? By answering these key questions, we will renovate our current view on the physical and chemical properties of active galaxies. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2013-11-29T05:27:00.000 |
| 1447 | 2013.1.00999.S | 4 | Lensing Through Cosmic Time: ALMA Constraints on "Normal" Galaxies in the HST Frontier Fields | We propose ALMA Band 6 imaging (FWHM=1.3", 0.35mJy @5sigma) of the first 4 massive strong-lensing clusters in the HST Frontier Fields, leveraging their >5-10 magnification to study high-z galaxies over the inner ~4 arcmin^2. These clusters have a wealth of ancillary ground/space-based radio-to-X-ray imaging, 1000s of high-quality spectroscopic and photometric redshifts, and exceptional lensing-mass models. Yet these important targets lack strong submm constraints. Our observations will allow (1) a probe of the 1.1mm number counts and luminosity function ~5-10x below published estimates, (2) individual and statistical characterization of high-z star formation via SED fitting/stacking of 10s-1000s of high-z galaxies and source reconstructions, (3) dust continuum constraints on the lensing cluster galaxies and ICM, and (4) a critical benchmark for future lensing-related projects with ALMA. The proposed data will inform us about how star formation proceeded in the early universe. This proposal is a large extragalactic Chilean key project with broad community support and funding, and considerable international expertise (including many on the CLASH science team). | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2016-08-12T18:01:07.000 |
| 1448 | 2016.2.00164.S | 18 | An Organic Exosphere on 1 Ceres? | Ceres, the target of the Dawn mission, is known to have a warm, liquid-bearing, interior that is rich in volatiles. The detection of aliphatic organic matter on an aqueously-altered body admits the possibility that extensive prebiotic synthesis could have occurred on Ceres, an object of intense interest for the study of primitive bodies and astrobiology nowadays. Observations of water absorption and hazes on Ceres point to the existence of an exosphere on this dwarf planet. Although organic species are present on the surface of Ceres, mechanisms such as sputtering by Solar wind particles, cryovolcanism and thermal sublimation would allow their removal into space, forming an organic exosphere. Based on a tentative detection of HCN emission on Ceres with the JCMT, we wish to further explore the possible organic component of this exosphere and determine the viability that the surface molecules originate from cometary impacts using the ACA 7-m Array. | Solar system - Planetary atmospheres, Solar system - Asteroids | Solar system | 2018-11-13T08:41:14.000 |
| 1449 | 2016.1.00291.S | 5 | The jet/outflow system in BHR71 | The interstellar medium (ISM) is constantly out-of-equilibrium, with energy continuously injected in various forms: mechanical, photons, or cosmic rays. The propagation of shocks is ubiquitous in the ISM, where it represents an important part of the mechanical energy input. In particular, shocks are generated by the birth of stars in the form of jets and bipolar outflows, where they play an important role in the evolution of the interstellar medium. The study of jet/outflows interactions is paramount to understand the star formation processes and scenarios, but also to evaluate the impacts of the shocks on the local interstellar medium. Unfortunately, in low-mass protostellar environments, these tasks are made difficult by the faintness of the jet component. For the first time, we propose to observe the jet/outflow system in the low mass protostellar outflow BHR71, where our complementary observations strongly suggest the presence of a high-velocity jet. With the requested observations, we will characterize the shocks associated to the jet and outflow, study their energetic and chemical impacts on the environment, and also evaluate their efficiency in accelerating cosmic rays. | Outflows, jets and ionized winds, Intermediate-mass star formation | ISM and star formation | 2019-06-12T00:00:00.000 |
| 1450 | 2022.1.00591.S | 104 | The 'Missing Link': Gas Accretion Flows in the Galactic Bar toward the Central Molecular Zone | We propose to observe 25 clouds in the Galactic bar with gas temperatures of tens of K and broad lines (>~10km/s) - these clouds are the best candidates for the gas flow that feeds the Central Molecular Zone (CMZ) of our Milky Way. Whereas the CMZ is a well studied region at all wavelengths (including the supermassive black hole Sgr A* and the vigorous star forming region Sgr B2), the streams that feed the CMZ have largely been neglected. Modelling shows that the gas likely follows x1 and x2 orbits in the bar potential, enforced by the bar potential, with gas accretion at various points and cloud-cloud collisions from dynamical effects like (self-)intersecting orbits and accretion overshooting. We propose to probe these processes by observing molecular lines that trace physical parameters such as shocks, turbulence, temperature, ionization etc. The ACA+TP is the perfect telescope for our study as it allows us to probe relatively large regions at molecular clump resolution with adequate sensitivity. The data will provide an invaluable grid of cloud properties for improved detailed dynamical models of the inner Galaxy. | Galactic centres/nuclei | Active galaxies | 2024-11-17T17:18:46.000 |
| 1451 | 2015.1.01584.S | 13 | A statistical study of molecular clumps in the triggered star-forming region M17SW | We propose a multi-line observation of dense molecular clumps toward M17SW. M17SW is a core of gint molecular cloud (GMC) interacting with an expanding HII region. The observation aims a statistical study of dense molecular clumps to confirm a triggered star formation (TSF) by the HII region. We will derive the spatial distribution of the size and the density using dense gas tracers such as H13CO+, HCN, and HCO+ in Band 3. This result will establish the relation between the HII region and the warm and dense shell near the ionized front through comparing with the numerical simulation. In addition, we will derive the initial fractal dimension of M17SW and the power index of the clump mass function (CMF) for the dense shell. Walch et al. (2013) suggest a unified model for TSF that predict the lower index of CMF for the TSF region is small when the initial fractal dimension of the GMC is low. The fractal dimension of M17SW would be low because it consists of clumpy structure. If the CMF for the TSF region of M17SW has flatter slope, this result supports and confirm the unified TSF model. | High-mass star formation | ISM and star formation | 2017-09-08T13:06:38.000 |
| 1452 | 2013.1.01016.S | 5 | An ALMA investigation of the environment around the young 2M1207b planetary mass object | At the distance of only 55 pc, the TW Hyadrae association harbors one of the most intriguing astrophysical systems: a young 8 Myr-old planetary mass object orbiting a low mass brown dwarf at a radius of 40 AU. Thanks to its proximity, very young age, and angular separation between brown dwarf and planetary mass object, the 2M1207 A & b system is probably the best candidate to investigate the physical environment of a very young planetary mass object down to a fraction of Lunar mass in dust mass. We propose to use the very high sensitivity and angular resolution provided by ALMA in Cycle 2 to search for dust thermal emission in the system. These observations will set tight constraints on the presence of material around a planetary mass object at the last stages of its formation. The characterization of the more massive disk known around the low mass brown dwarf will shed light on the structure of disks surrounding young objects close to the deuterium burning limit. | Disks around low-mass stars | Disks and planet formation | 2015-11-24T18:06:41.000 |
| 1453 | 2017.1.00107.S | 1939 | Probing the Grain Growth Signatures in rho-Ophiuchi Young Stellar Objects | When and how do interstellar dust grains with micron-size grow to millimeter-size in circumstellar disks around young stellar objects (YSOs)? Previous observations have revealed the grain growth signature in the majority of the disks around Class II sources. On the other hand, our recent analysis of the Class 0 sources shows no firm evidence of grain growth in these sources. These results suggest that the effect of grain growth on the dust opacity index (beta) becomes prominent before the Class II stage, but no earlier than the late-class 0 stage. We, therefore, hypothesize that the grain growth signature becomes significant in the circumstellar (pseudo-)disks around Class I YSOs. In order to test this hypothesis, we plan a dedicated survey for beta in circumstellar (pseudo-)disks around various evolutionary stages of YSOs from Class 0 to early Class II in the rho-Ophuchi molecular cloud. ALMA is an ideal instrument for conducting this survey because of its superb sensitivity. We plan to obtain the continuum data in Band 6 (1.3 mm), Band 4 (2 mm), and Band 3 (3.3 mm), derive the beta values, and constrain the earliest signature of grain growth. | Low-mass star formation | ISM and star formation | 2019-04-20T02:48:52.000 |
| 1454 | 2016.1.00980.S | 60 | After the Fall: Zooming In on the Molecular Fuel in Post-Starburst Galaxies | Contemporary models of galaxy evolution require feedback to expel a substantial fraction of the gas and dust fueling stellar and black hole growth, driving galaxies into quiescence. Post-starburst galaxies are systems found precisely in this phase - shortly after star formation has been abruptly halted - but little is known about the dust and gas content of these systems. We have recently discovered surprisingly large reservoirs of dust and molecular gas in a sample of post-starbursts, and have mapped 4 quenched galaxies spanning a range of post-burst age with ALMA in CO2-1 at ~1.5kpc resolution. These maps reveal compact and disturbed gas kinematics along with potential outflows. To understand the fate of molecular fuel after quenching, we propose deep CO 2-1 maps zooming in on 4 post-starbursts previously mapped by ALMA. These galaxies span a wide range of post-burst ages, and all have well-measured molecular gas and dust masses together with other vital dust, neutral gas, and ionized gas tracers. With ALMA's remarkable sensitivity and resolution, we can directly target the 0.15"=~200pc scales of large GMCs to directly probe the kinematic and physical state of the gas. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2017-10-27T19:35:48.000 |
| 1455 | 2022.1.00338.L | 231 | The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) | ExoKuiper belts are a ubiquitous component of planetary systems that provide a unique window into their outer regions (where only Jupiter-mass planets are currently detectable), constraining their architecture, formation and evolution. ALMA has revolutionized this field by characterizing in detail the structure of 6 belts, revealing radial and vertical substructures that hint at the presence of low mass planets, as well as unveiling their gas components. We propose ARKS to characterise 18 exoKuiper belts to understand the diversity and ubiquity of radial and vertical substructures and study their gas kinematics in a systematic way. We will systematically search our targets for signatures of planets with masses as low as Neptune's shaping the radial distribution, bodies as small as Pluto stirring the disc, and Saturn-mass planets distorting the gas rotation, all within the 30-300 au unexplored region in the planet mass and orbital radius space. Our program will provide a definitive characterisation of all exoKuiper belts bright enough to resolve radial and vertical substructures with ALMA, and our products will become a fundamental legacy to further studies of exoplanetary systems. | Debris disks, Exo-planets | Disks and planet formation | 2024-01-18T14:50:06.000 |
| 1456 | 2017.1.01177.S | 18 | Connecting the CO and neutral hydrogen gas in DLA host galaxies at z=0.45 and z=0.59 | We propose to use ALMA to detect and image the molecular gas in the host galaxies of two 21-cm HI DLA systems (at z=0.45 and 0.59) detected in a pilot study with the Australian SKA Pathfinder (ASKAP) radio telescope. Our main goal is to connect the neutral atomic (HI) and molecular (CO) gas within individual galaxies at a lookback time of 5-6 Gyr, and so provide a more complete picture of the typical baryonic gas reservoir within normal galaxies at this epoch. Observations of the CO (2-1) emission line will allow us to characterise the host galaxies of these z ~ 0.5 DLA systems through measurements of the mass and kinematics of their molecular gas, as well as measure the impact parameter of the sightline along which we see 21-cm HI absorption. Finally, both our targets are on sightlines to radio-loud QSOs that are bright (0.5-1.0 Jy) unresolved continuum sources at 150 GHz, allowing us to seach for CO (2-1) absorption along the same sightline as the HI DLAs. | Damped Lyman Alpha (DLA) systems | Cosmology | 2019-02-21T14:37:59.000 |
| 1457 | 2018.1.00897.S | 25 | Can we trust 'dense gas tracers' to trace dense gas? | The optical depth of "dense gas tracers" plays a main role in setting their effective critical density, and so their density sensitivity. But because the optically thin isotopologues used to probe optical depths are very faint, good measurements of the optical depth are rare outside the Milky Way and the brightest starbursts. To improve this situation, we propose to use ALMA Band 3 to simultaneously measure the emission coming from dense gas tracers, HCN and HCO+, and their isotopologues, H13CN and H13CO+, in the center, bar, and off-nuclear star forming region of the nearby galaxy NGC 3627. NGC 3627 is a barred spiral with inner structure that resembles those in the Milky Way. These observations will allow us to make the among first measurements of the optical depth and effective critical density of the main extragalactic dense gas tracers in a normal star-forming galaxy. These measurements are crucial to understand what gas is traced by these lines, and how to use HCN or HCO+ luminosity to dense gas mass. The faint nature of this lines make this an experiment that only ALMA can do. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-11-01T15:36:18.000 |
| 1458 | 2011.0.00084.S | 0 | The V4046 Sgr Disk: A Benchmark for Planetesimal Evolution_(Rev_0.8) | We propose a 2-hour "compact" configuration observation of the CO 6-5 line and 700 GHz continuum emission from the unique, nearby (73 pc), and "old" (8-20 Myr) disk around V4046 Sgr. The proximity and age of this massive, gas-rich disk offer a rare opportunity to observe the subtle effects produced by the growth and migration of its solid contents with high sensitivity and spatial resolution. The proposed ALMA observations will be used in tandem with our SMA data (CO 2-1 and 230 GHz continuum) to make two key measurements: (1) use the resolved CO 6-5/2-1 line ratio to determine the gas temperature profile and effective size of the gas disk relative to the dust, a key indirect diagnostic of the radial variation in the gas-to-dust ratio that should be induced by the inward radial drift of solids; and (2) compare the continuum emission morphologies at 700 and 230 GHz to search for evidence of the particle size segregation expected in solid migration models. Although studying these effects is a relatively new topic enabled only now with the start of ALMA science operations, the size and spatial evolution of disk solids is perhaps the most fundamental aspect of the early stages of planet formation. The V4046 Sgr disk is an ideal proving ground for planning future observations of these effects, as well as for highlighting how ALMA data permit rapid, significant progress toward more sophisticated analyses of circumstellar disk evolution and the formation of planetary systems. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2014-02-28T21:15:00.000 |
| 1459 | 2018.1.01644.S | 5 | Constraining the Mass of the Planet in the Gap Discovered in the TW Hya Disk | We propose to observe the 13CO and C18O J=3-2 line emission towards TW Hya with high spatial resolution and high sensitivity in order to detect a gas gap in the disk. Our cycle 3 DDT multiple-band observations show multiple gap structure in dust continuum emission and an enhancement of dust spectral index at the gap at the disk radius of 22AU, which suggests the gap is likely to be caused by a planet. This proposal aims to constrain the mass of the planet by measuring the depth and width of the gas gap at 22AU. In order to derive the planet mass precisely, we need to know the properties of the gas gap, rather than the dust gap, since the distribution of dust is affected by dust filtration. At the 22 AU gap, the C18O line is optically thin and a good tracer of gas surface density distributions together with the optically thick 13CO line as a tracer of gas temperature at the gap. Our cycle 4 observations have been partially performed and show a hint of gas gap at 22AU. This proposal is to complete out cycle 4 observations. This will be a pioneering study of the formation environment of a planetary system, taking advantage of the TW Hya's proximity. | Disks around low-mass stars | Disks and planet formation | 2021-01-30T17:11:39.000 |
| 1460 | 2022.1.00951.S | 78 | Revisiting the slope of black hole scaling relations for spiral galaxies | The evolution of massive black holes (MBH) and their host galaxies appear to be closely connected as several tight scaling relations suggest. It is still debated what exact evolutionary path galaxies of different morphology follow. Sahu et al. 2019 compiled MBH masses derived from different dynamical tracers and showed that early-type and late-type galaxies (ETG/LTGs) follow scaling relations with very different slopes. When only using the subset of MBH masses derived from cold gas, we noticed that the LTGs significantly deviated from the Sahu et al. 2019 relations. We propose to use ALMA observations to derive robust dynamical measurements of MBH masses in a sample of 12 nearby LTGs. The high resolution of ALMA observations will map the kinematics of the rotating nuclear molecular gas disk, resolve the black holes' sphere of influence, and allow us to measure the MBH mass precisely. Our measurements will provide new constraints (1) on the slope of the LTG scaling relations and the cause of the mentioned discrepancy, (2) on the pitch angle - MBH scaling relation as diagnostic tool for low-mass LTGs and (3) on the secular evolution of LTGs with respect to their central black hole. | Spiral galaxies, Galactic centres/nuclei | Local Universe | 2024-04-17T12:22:35.000 |
| 1461 | 2017.1.00172.S | 70 | Stellar feedback and physical conditions of molecular gas around low-metallicity super-star clusters | Feedback from accreting black holes and from massive stars and supernovae has become a cornerstone for our understanding of galaxy evolution. However, there are currently few observational constraints for stellar feedback, especially for the effect of metal-poor young, massive, super-star clusters (SSCs). In order to quantify physical conditions in the molecular gas around SSCs, we propose 12CO(1-0), 12CO(2-1), 12CO(3-2), 12CO(4-3), and [CI](1-0) maps at 40 pc resolution of a low-metallicity dwarf starburst, NGC 1140 (0.3 Zsun), hosting 6-7 SSCs; these transitions have already been detected with single-dish measurements. Our proposed observations will characterize the molecular gas morphology, kinematics, gas temperature, H2 density, and atomic carbon abundance in the metal-poor interstellar medium (ISM) surrounding the SSCs. We will compare our results with recent models of ISM chemistry and star formation, to better quantify the effects of stellar feedback for input to galaxy evolution models. ALMA will provide an observational perspective on the effects of stellar feedback in an extreme environment which may be representative of the ISM in high-redshift galaxy populations. | Dwarf/metal-poor galaxies | Local Universe | 2019-09-14T18:17:38.000 |
| 1462 | 2013.1.01113.S | 6 | Probing the physics and chemistry of the candidate first-hydrostatic core Chamaeleon MMS1 | The First Hydrostatic Core (FHSC) constitutes one of the first milestones in theoretical models of low-mass star formation. This proposal aims to elucidate the nature of the low-luminosity infrared source Chamaeleon MMS1 (Cha-MMS1), to help resolve the dichotomy of whether it is an FHSC or merely a low-luminosity Class 0 protostar (VeLLO). We propose to map at high angular resolution the spectroscopic signatures theorised to be characteristic of FHSCs and VeLLOs, including CO and CS emission from the outflow and H2CO, CH3OH and HC3N emission from the hot core. Based on current numerical simulations, the detection of a spatially compact (<200 AU), low-velocity CO outflow will consitute strong evidence in favour of Cha-MMS1 being the first confirmed FHSC. On the other hand, the detection of H2CO and/or CH3OH inside the core will provide evidence for the presence of a (>100 K) hot corino, which would instead identify Cha-MMS1 as a Class 0 protostar. High spectral-resolution CS line profile observations will provide information on the infall and outflow properties of the source. HC3N will be observed as a probe of carbon-chain chemistry. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2016-09-04T23:20:14.000 |
| 1463 | 2015.1.00907.S | 56 | Smoking gun confirmation of dusty nuggets as progenitors of the red nuggets at z~2 | The discovery of the "red nugget" population (massive, compact, quiescent galaxies) at z=2 indicates that early passive galaxies were remarkably compact compared to their present-day elliptical counterparts. Recent observations have identified a population of compact, star forming galaxies (so-called "dusty nuggets") that appear to be the direct progenitors of the red nugget galaxies. While several pieces of indirect evidence link these two populations, ALMA observations will provide the smoking gun confirmation that dusty nugget galaxies are the star forming progenitors of the first generation of red sequence galaxies. Therefore, we request 3.5 hours to obtain Band-7 luminosities, continuum and CO maps on 4 dusty nuggets to: (a) determine if their star-forming components are as compact as the stellar components of red nuggets, (b) verify a short quenching (gas depletion) timescales consistent with the rapid build up the red nugget population and (c) resolve their gas kinematics. | Galaxy structure & evolution | Galaxy evolution | 2018-01-10T02:03:53.000 |
| 1464 | 2018.A.00031.T | 95 | Exploring the dust, thermal gas, and new methanol masers in the third massive protostellar outburst: G358.931-0.030 | The first identification of accretion outbursts in massive protostars happened in two separate regions within the past two years, profoundly impacting the field of massive star formation. Because both events were accompanied by maser flares, single-dish maser monitoring programs were reinvigorated. As a result, a third event was discovered on 14-Jan-2019 in a poorly-studied massive star-forming region, G358.931-0.030. Since then, the global maser community has made the astounding first discoveries of numerous torsionally-excited methanol maser lines from 6-360~GHz, all likely powered by the ongoing accretion outburst. Because this outburst has been caught in a much earlier stage, we have the best opportunity yet to explore and understand the underlying mechanism. Much like NGC6334I-MM1, the lack of a near-IR counterpart indicates a very deeply-embedded protostar. ALMA DDT observations are now critical to provide a clear picture of star formation in this protocluster by pinpointing the outbursting protostar with respect to the masers before they fade, and placing their kinematics into context of the dust and thermal gas structures that trace protostellar accretion and outflow. | High-mass star formation | ISM and star formation | 2020-02-23T21:08:22.000 |
| 1465 | 2015.1.00260.S | 99 | A survey for CO[5-4]emission in star forming galaxies at 1.1<z<1.7 | We propose to detect CO[5-4] (and the 520um rest-frame continuum as a bonus) for 127 galaxies at 1.112 measured by Herschel, including similar numbers of main sequence and starburst galaxies. Thanks to our direct detection with IRAM PdBI of CO[5-4] in a small sample of comparable objects, and evidence of a linear LIR to LCO[5-4] relation, we can reliably estimate required integration times that are of order of 1 minute per galaxy, enough also for continuum detections. For all these targets we will have a measurement of high-J CO[5-4] luminosity, LIR, Mdust and Mgas (from continuum) and of U=LIR/Mdust, the hardness of the radiation field. We will be able to perform an unprecedented investigation into the nature of star formation inside high-redshift galaxies, statistically confirm the supposed linear relation between LIR and L'CO[5-4] and measure its scatter and systematics for different galaxy types, and explore the correlation between CO excitation and star formation efficiency. With 6.2h of ALMA observing time in Band6 we will obtain the first statistical sample of CO detections in the z~1.4 Universe. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2017-06-08T09:23:43.000 |
| 1466 | 2011.0.00612.S | 0 | An Off-Nuclear Starburst in the Luminous IR Galaxy IIZw96 v1.1 | The infrared luminous merger IIZw096 contains an extremely compact off-nuclear starburst that is the source of more than 80% of the total infrared luminosity. IIZw096 is a rare example of a galaxy caught in the early merger stage of driving its vast reservoirs of molecular gas inward toward what will become the merger remnant and is reminiscent of the more famous merging galaxy NGC4038/9 (the Antennae) but an order of magnitude more luminous at log(LIR/Lsun) = 11.94. We propose to map the off-nuclear starburst on spatial scales of 0.25"-3.0" over the entire starburst region. Given the small spatial extent and the need for extremely high sensitivity and spatial resolution, we request extended and compact array observations in Band 9 to trace the molecular gas via CO J=6-5, HCO+ J=8-7 and HCN J=8-7, and to measure the 450um dust continuum all on scales of 200-300 pc. The resulting high spatial resolution maps will allow comparisons between the distribution of the bulk of the molecular gas (via CO J=6-5) and dust (at 450um), the location of higher density clumps (from HCO+ J=8-7 and HCN J=8-7), and structures seen in the near-infrared. The velocity will reveal possible infall or outflows of gas as well as pinpoint the dynamical center and how it relates to the density and temperature of the gas. Together the morphology and kinematics of the dense (cool) molecular gas that dominates the mass and fuels the star-formation will reveal the precise nature of the starburst and ultimate fate of the system. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2013-10-19T19:50:00.000 |
| 1467 | 2013.1.00576.S | 10 | Observations of the [CII] Emission Line in Hot-Dust Obscured Galaxies | The WISE mission has recently identified a rare population of high-redshift, hyper-luminous infrared galaxies, all with bolometric luminosities above 10^13 L_Sun, and many exceeding 10^14 L_Sun. Characterized by their extremely red mid-IR colors and very hot dust temperatures, these hot, dust obscured galaxies (Hot DOGs) likely probe a key stage in the galaxy evolution paradigm. The bulk of the IR emission in Hot DOGs is powered by AGN activity, outshining possible fainter cold emission associated to star formation. The only way to study the ISM properties of the host galaxy in these objects, as well as the effects of the AGN on it, are through kpc-scale imaging of the dust and gas at sub-mm wavelengths. We propose here to use ALMA to obtain deep, high-resolution observations of the 157.7um [CII] emission line and of the FIR continuum in a small sample of carefully selected Hot DOGs to constrain the physical properties of the their dust and gas components and gain insights into their star-formation properties. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2017-11-08T00:00:00.000 |
| 1468 | 2016.1.01015.S | 42 | The Extreme UV through ALMA's Eyes: a unique probe of the ionizing spectrum of OB Stars | The extreme ultraviolet (EUV) of OB stars cannot be probed directly from the ground or from space; their EUV are thus very poorly constrained. Our theoretical work demonstrates that the mm/submm recombination lines of HI and HeII are excellent probes of the EUV: they have little dust absorption, they arise from H and He (thus independent of metallicity) and their fluxes depend linearly on number of EUV continuum photons. The He++ region (producing HeII emission) requires 54 ev photons, thus the EUV hardness is directly probed by the HeII/HI flux ratio. We propose observations of HI and HeII in compact OB star regions. These observations will open a new observing window on the EUV, getting down to a He+ line strength ~0.001 of HI. The measured hardness of the EUV spectra will provide critical input to starburst synthesis models. | Main sequence stars | Stars and stellar evolution | 2018-05-25T05:58:53.000 |
| 1469 | 2021.1.00800.S | 5 | The First Kinematic Mass Estimate of a z>6 Black Hole | Current black hole mass estimates for some z>6 quasars yield impressively large masses, often exceeding 1 billion solar masses; challenging models of the early formation of supermassive black holes. However, these estimates are solely based on rest-frame UV/optical scaling relationships derived in the local Universe, which need not hold at high redshift. There is therefore a dire need to validate these scaling relationships at high redshift. This is exactly the aim of this proposal. Using 0.04" resolution imaging of the [CII] emission line, we aim to resolve the black hole sphere of influence for the z=6.8 quasar J0109-3047, which has a black hole mass of 1.5 x 10^9 Msun. The expected increased velocity dispersion within this central region of the galaxy will give an independent, kinematic measurement of the mass of the black hole. Previous observations have shown that not all quasars are suitable for these measurements due to the extreme high gas densities within their central region. J0109-3047 is the only quasar for which this measurement is possible within 10 hours of on-source observation time; providing the first kinematic mass measurement of a z>6 black hole. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2022-11-10T19:31:29.000 |
| 1470 | 2024.1.00071.S | 0 | The first systematic survey of [NII] in z>6 quasars | We propose to perform the first systematic survey of [NII] fine-structure line emission in quasar host galaxies at z>6. The two targeted transitions, [NII] 122um and [NII] 205um, are powerful diagnostics of the ionized ISM. They enable a direct measurement of the ionized gas density and the mass of ionized gas (~1% of the ISM mass in local spirals, possibly as large as ~30% at high-z). Furthermore, together with the (already secured) [CII] 158um line, they enable to gauge the relative contribution of PDR/XDR vs HII regions to the [CII] emission. These diagnostics have been exploited in only six 16) will shed light on the balance of ISM phases in the most massive galaxies in the early Universe, and inform the next generation of numerical simulations modeling their formation. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2025-11-14T10:17:19.000 |
| 1471 | 2022.1.00863.S | 303 | Confirming significant dust-obscured star formation at z>3 in a new ultra-deep radio survey | Tracing the star formation history of the universe at redshifts z>2 is significantly complicated by the presence of likely substantial yet uncertain dust attenuation. Recently, a new ultra-deep radio survey has been carried out in the premier COSMOS field with the VLA (COSMOS-XS), putting state-of-the-art constraints on the dust-unbiased star formation rate density (SFRD). However, `optically dark` galaxies could not be included due to their unknown redshifts. Using a super-deblending technique on the wealth of FIR data, we have now derived FIR-based photo-zs for the sources, including 10 S_1.1>3.5 mJy sources with estimated redshifts z=3.4-7.5 and SFRs=550-1100 Msol/yr based on current estimates, comprising a full ~50% of the total SFR of the optically dark population. Here we propose ALMA 3mm spectral scans of these 10 sources, which (in combination with the super-deblended photometry) has proven 100% successful in confirming spectroscopic redshifts. This will allow us to place important constraints on the relative contribution of such optically dark sources to the SFRD and determine the importance of dust-obscured star formation in general at the highest (z>3) redshifts. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-03-27T18:22:28.000 |
| 1472 | 2013.1.01147.S | 18 | Planet formation at a critical age: debris disks with gas in the 8 to 20 Myr range | The η Chamaeleontis association and the β Pictoris moving group of young low-luminosity nearby stars, represents an ideal laboratory to study planet formation at a critical age range: between 8 and 20 Myr. This stage is regarded as post protoplanetary/primordial disk, hence they are assumed to be young debris disks. We propose to conduct ALMA band 6 observations of 10 systems with clear excesses of emission at long wavelengths, evidencing the presence of circumstellar disks. Some of these systems may also contain disks with inner cavities (based on SED studies). The aims of this proposal concern mainly the determination of disk masses, sizes and detect primordial gas. Recent studies have shown evidence that some of these ’debris’ disks might still contain appreciable quantities of gas, challenging the idea that most disks lose all their gas at a rather early age (2-10 Myr). | Debris disks | Disks and planet formation | 2016-12-03T18:20:03.000 |
| 1473 | 2022.1.00303.S | 900 | Testing the origin of warm carbon-chain chemistry in Perseus protostars | Carbon-chain molecules (CCMs) are thought to form efficiently in prestellar stage and quickly disappear in protostellar stage due to the rapid conversion of C to CO. However, detection of CCMs in embedded protostars challenges this paradigm. The warm carbon-chain chemistry (WCCC), initiated by sublimation of CH4, was proposed to explain the observed CCMs in protostars. While single-dish surveys find that CCMs almost ubiquitously appear in protostellar cores, whether active WCCC leads to the existence of these CCMs remains unclear. To test the CH4 origin of CCMs, we propose a survey of key CCMs, C2H and c-C3H2, toward an unbias sample of protostars in the Perseus molecular cloud. We will map the emission of CCMs at a few thousands au scale, where the WCCC is expected to be active, and further constrain their excitation. In this survey, we will directly confirm the existence of warm and concentrated CCMs, indicative of active WCCC. Thus, the origin of CCMs will be unambiguously determined. | Low-mass star formation, Astrochemistry | ISM and star formation | 2024-10-04T07:35:38.000 |
| 1474 | 2017.1.00040.S | 361 | Replenishing Molecular Gas Near the Supermassive Black Hole SgrA* | The detection of the 2-pc circumnuclear disk (CND) immediately around the Milky Way supermassive black hole (SMBH), SgrA*, provides an unique laboratory to study SMBH accretion at sub-pc scales. Theoretical model predicts that the CND was formed through the tidal disruption of nearby molecular clouds. Indeed, our previous CS(2-1) and HCN(4-3) maps with ALMA and SMA revealed that the streamers surrounding the CND are the tidal debris captured from the nearby clouds. The streamers show inflow motion and finally ends up co-rotating with the CND. We also found that the key elements - compact cores - inside the streamers may be the infall seeds or the sites of star formation. We propose to obtain a 0.5"-1" resolution map with the 5 CS lines to resolve the compact cores in the streamers and the CND. With the unprecedented ALMA maps, we will, (1) Measure the CND and streamers mass ratios to evaluate the importance of the inflow and SMBH feeding. (2) Measure the densities and sizes of the compact cores to derive the "surviving fraction" as a function of distance to SgrA*. (3) Fit the inflow kinematics to constrain theoretical models for their dynamics and fates. | Galactic centres/nuclei | Active galaxies | 2020-01-09T00:00:00.000 |
| 1475 | 2015.1.00820.S | 136 | Dark Matter in Dwarf Galaxies | The dwarf galaxy dark matter survey described in this proposal will measure the radial distribution of dark matter (DM) in a sample of 13 DM dominated dwarf galaxies. The goal of the project is to determine the functional form of the DM distribution on scales of a hundred parsecs, and the degree to which the DM varies from galaxy to galaxy as a test of the Lambda CDM model on small scales. The scope of the project will permit for the first time the possibility of correlating the DM properites with other galaxy properties such as mass, gas density, star formation history, etc. We will measure the DM distribution by combining 2-D velocity fields of the galaxies in CO, which provides the least biased and coldest kinematic tracer at small radii together with Palomar Halpha integral field spectroscopy to extend the measurements to larger radii. Together with near-infrared imaging to secure the stellar mass distribution, we will remove the baryonic contribution to the observed rotation and model the kinematics. This data set will be the largest homogenious survey of the DM in the inner regions of galaxies undertaken to date. | Surveys of galaxies | Galaxy evolution | 2017-04-27T14:59:57.000 |
| 1476 | 2017.1.01565.S | 215 | A comprehensive inventory of nitrogen isotopic ratios in a nascent solar system | Understanding the origin and evolution of the solar system's organic material is a central question in astrochemistry. The nitrogen isotopic ratio, 14N/15N, is one of our main tools to trace the history of the organics. Because the highest 15N-enrichments in the solar system exist in the most pristine organic matter in meteorites, an inheritance from the earliest stages of solar system formation is likely. However, measurements of the 14N/15N ratio in star-forming regions so far present a puzzling picture, with 15N being enriched in certain molecular tracers but not in others. We propose to precisely measure the 14N/15N ratio from a comprehensive set of tracers in a young solar system analog, using for the first time not only simple molecules, but also complex organics. The proposed observations will provide us with a consistent set of spatially resolved 14N/15N measurements to investigate differences between molecules deriving from the atomic versus molecular nitrogen reservoirs. With the complex organics, we will also take a first step towards understanding how the 15N-enrichments in the gas are eventually incorporated into the organic matter of meteorites and cometary ices. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-03-26T11:04:11.000 |
| 1477 | 2016.1.00193.S | 183 | The substructure of molecular clouds in the LMC | We propose to map a sample of four molecular clouds, each roughly 40 pc in diameter, distributed across the LMC and exhibiting a range of star formation activity. With ALMA we will mosaic the full extent of each cloud in the J=1-0 transitions of CO and 13CO. Our survey is distinct from previous efforts in mapping a wide area of each cloud, not just the CO peak position or star formation `hot spots', and observing both optically thin and thick species to derive column densities and excitation temperatures. Our immediate objective is to quantify the statistics of density and velocity fluctuations that can be directly compared among our cloud sample, with Galactic counterparts, and with numerical simulations. The dependence of these statistics on location within a cloud, location within the galaxy, and star formation activity will provide much-needed empirical benchmarks for theories of cloud formation, evolution, and dynamical stability. | Low-mass star formation | ISM and star formation | 2018-02-23T02:34:59.000 |
| 1478 | 2012.1.00940.S | 4 | Nature of a Flat Face, Energetic High-Velocity Compact CLoud in the Galactic Center | High-velocity compact cloud (HVCC) is a peculiar population of molecular cloud found in the central molecular zone of our Galaxy with the NRO 45m telescope CO J=1-0 survey. They have compact size, extremely large velocity width, and enormous kinetic energy ranging from 1E49 to 1E52 ergs, while their driving sources are still unidentified. CO -0.40-0.22 is one of energetic HVCC (Ekin ~ 1E51 erg) with a featureless appearance. Our observations with ASTE have revealed that it has intense CO J=2-1 and HCN J=3-2 emission suggestive of high density and moderate temperature. We propose to make 7-point mosaic observations of CO -0.40-0.22 with ALMA. HCN J=3-2 and CO J=2-1 lines will be observed to obtain detailed spatial-velocity information to diagnose its kinematics: (1) rotation around a dark mass, (2) expanding shells/bubbles, or (3) supersonic collision. Cases (1) and (2) are indicative of an embedded, aged super star cluster (SSC), which could be a womb of intermediate mass black hole. Detection of rotating motion may enable us to calculate the enclosed mass and thereby to examine the existence of an IMBH within CO -0.40-0.22. | Early-type galaxies | Galaxy evolution | 2016-03-16T13:19:50.000 |
| 1479 | 2013.1.01329.S | 21 | Feeding and Feedback in the central region of NGC 613 | We propose to observe the central region of the nearby galaxy NGC 613 (17.5 Mpc) in Band 3 (HCO+ and HCN 1-0, CS 2-1, SiO 2-1 and 100 GHz continuum) and in Band 7 (HCO+ and HCN 4-3, CS 7-6 and CO 3-2) with 0.25” (21 pc) and 0.5” (42 pc) resolution, respectively. We detected hot gas in the central region. ALMA observations resolve the circum-nuclear disk, nuclear ring and jet/outflow. It observationally reveals following important topics of fueling process of AGN. 1. We reveal inflow gas from nuclear ring to center by kinematic analysis of CO 3-2 assuming circular rotation of the nuclear ring. 2. We estimate kinematic energy of the outflow gas using the identified direction of the outflow from the nucleus. 3. We identify heating source (X-ray, shock) of the hot gas in the circum-nuclear disk using distribution of shocked gas traced by SiO and physical condition of the gas derived from intensity ratio of HCN, HCO+, CS and CO. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 3000-01-01T00:00:00.000 |
| 1480 | 2022.1.00134.S | 54 | Band 6 ACA Photometric survey of double-belts debris disks | Debris disks are a common feature of mature planetary systems, and SED modeling has shown that double-belt configurations similar to the Solar System's asteroid and Kuiper belt are common as well. While it is important to understand the architecture of these systems, degeneracy between radial structure and grain size distribution and composition plagues SED modeling efforts. However, at mm wavelengths, the emission is largely dominated by the coldest of the two belts, and its spectral slope is mostly sensitive to its dust grains' size. Therefore, we propose here to observe a sample of double belt debris disks discovered through SED modeling of Herschel data, making use of the ACA only. By obtaining the slope of the cold belt SED at mm wavelengths, and in conjunction with the Herschel measurements, we will be able to determine its grain size distribution, refine architectural constraints obtained through SED modeling by disentangling the cold belt SED from that of the warm belt, and determine disk masses with more accuracy. | Debris disks | Disks and planet formation | 2024-10-04T14:42:07.000 |
| 1481 | 2018.1.00850.S | 269 | From filaments to cores: Dynamics in infrared dark clouds | Massive stars shape the visible Universe, yet we do not know how they form. Currently available observations of massive star forming regions reveal a complex hierarchical structure from the global (cloud) to intermediate (filament) to individual forming star scales (cores). However, due to the lack of observations on the intermediate-to-small scales, constraining the role of these structures in the theoretical models of massive star formation is not possible. The proposed observations of a statistically meaningful sample of quiescent massive star forming clouds will allow us to: (1) separate the complex kinematics spatially and spectrally, in order to create a catalogue of coherent, filamentary structures; (2) place the properties of these structures in the context of the larger scale environment, and of the core distribution and properties identified from the proposed continuum observations; (3) Constrain the theoretical models that provide predictions regarding the role of these structures (as for e.g. mass flows) and their formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-07-08T17:43:35.000 |
| 1482 | 2017.1.00225.S | 42 | FIR [O III] and [C II] emission from a z ~ 8 candidate galaxy: A glimpse into early production of heavy elements | We propose ALMA observations of a candidate z ~ 8.4 Lyman break galaxy (LBG) in the [O III] 88 micron and [C II] 158 micron lines at Band 7 and 5, respectively. In our A-graded Cycle 4 observations of this LBG, we made a 6.3-sigma detection of dust continuum emission and a marginal detection of [O III] 88 micron which suggests z_spec = 8.433. If confirmed, this will be the furthest galaxy which ALMA identifies spectroscopically. Furthermore, the proposed observations allow us (1) to characterize metal/dust enrichment for the first time when the age of the Universe was only 600 Myr and (2) to evaluate the escape fraction of ionizing photons using the [OIII]/[CII] luminosity ratio. ALMA will therefore provide a very unique opportunity before the JWST and ELT era that allows a tantalizing glimpse into the earliest production of heavy elements. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-12-03T13:45:09.000 |
| 1483 | 2013.1.01223.S | 12 | Star formation laws and AGN activity: CO (2-1) observations of ZEUS z~1.2 [CII] sources | We propose to use ALMA in Band 3 to image the CO 2-1 line from four sources at z ~ 1.2 from which we have detected the [CII] line with ZEUS/CSO. The low-J CO lines arise from PDRs and will allow us to constrain the physical conditions of the photo-dissociated regions in our sources and evaluate the possibility of an XDR contribution. In three of the four sources we will marginally spatially resolve the CO. Based on our [CII] work, we expect very large scale (~ 5 kpc radius) molecular disks in our sources. If these galaxies are forming stars in the “quiescent mode”, we expect very large molecular gas mass surface densities as well. These are required to support Schmidt-Kennicutt law star formation at the very large rates reflected in the FIR continuum and our [CII] line studies. We will also measure the underlying (rest-frame) 1.3 mm continuum emission as a proxy for the spatial distribution of the FIR continuum radiation and hence get a good handle on the spatial distribution of the surface density of star formation. We will compare this to the surface density of molecular gas (from our CO line map) to derive the star formation law within these galaxies. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2016-11-13T20:16:05.000 |
| 1484 | 2018.1.01864.S | 43 | First detection of 15N2H+ - a sink for interstellar heavy nitrogen? | Nitrogen isotope fractionation in prestellar cores, protostars, and protoplanetary disks is still not well understood. Because the main reservoirs, N2 and N, cannot be measured directly, our measurements rely on observations of tracer molecules. A particularly puzzling picture is thereby presented by N2H+, which shows not only a large scatter in 14N/15N ratios, but also strong depletion in a prestellar core, which current fractionation models cannot explain. One possible scenario is that 15N is hidden from our current view in the form of doubly substituted 15N2H+, similar to the high abundances of doubly deuterated molecules. Predictions for laboratory spectroscopy of 15N2H+ were recently published and allow us to search for 15N2H+ for the first time. We propose to search for 15N2H+ in the prestellar core 16293E, for which N15NH+ was already detected. These observations will prove the first measurement of a doubly 15N-substituted molecule, investigating their importance in nitrogen isotopic fractionation, and thereby advance our understanding of the origin of the nitrogen isotopic heterogeneity of the solar system. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2020-01-15T18:44:45.000 |
| 1485 | 2018.1.00836.S | 45 | The inventory of peptide-like molecules towards low-mass protostars | The molecules HNCO, CH3NCO, NH2CHO and CH3C(O)NH2 have structures that are similar to peptide bonds, [-(H)N-C(O)-], the chemical links in proteins, and thus can be precursors to biologically relevant molecules. These four molecules have been suggested to form through related reactions on interstellar dust grains. Unbiased observational constraints on their presence and abundances are limited to just one low-mass source (IRAS 16293--2422B), however. We propose to observe these molecules towards two additional low-mass protostars, NGC 1333 IRAS4A and Serpens SMM1. The aims are to: I) determine how common these molecules are around low-mass protostars, II) derive their abundances to constrain their chemistry and III) make a chemical comparison with IRAS 16293-2422B. The data will help us understand the formation pathways of these molecules, indicate whether ice or gas-phase chemistry is involved and determine how these species are chemically related to each other. | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-08-30T12:21:48.000 |
| 1486 | 2022.1.01013.S | 45 | Tracking the Millimeter Emission from the Relativistic Tidal Disruption Event AT2022cmc | Transient accretion onto a supermassive black hole through the tidal disruption of a stray star offers a unique opportunity to probe the environment around quiescent galactic nuclei and to map the lifecycle of relativistic jets and outflows. In 2011, radio and millimeter observations of the tidal disruption event (TDE) Swift J1644+57 revealed that these dramatic events can power luminous relativistic jets. Nevertheless, observations have revealed that powerful jets in TDEs are extremely rare; despite over a decade of searching, Swift J1644+57 remains the only well-studied jetted TDE to date. In this proposal we request millimeter observations of the recently discovered transient AT2022cmc, the first TDE observed to launch a powerful relativistic jet in 11 years. The observations proposed here will measure a possible jet break, track the peak of the spectral energy distribution (SED) as it evolves through the millimeter band, and determine the spectral index of the optically thin portion of the SED, uniquely determining the outflow kinetic energy, jet collimation, and the density profile around the SMBH. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2024-07-26T01:11:49.000 |
| 1487 | 2018.1.00744.S | 348 | Evolution of outflow-envelope interactions in low-mass protostars | We propose ALMA observations to study the evolution of the outflow-envelope interaction using a sample of 21 low-mass protostars at different evolutionary stages in the Orion A molecular cloud. We will conduct multi-line observations of the environment around these protostars that will allow us to trace the distribution of the outflowing gas (and its momentum and energy) with respect to the kinematics and structure of the infalling envelope. We will map each source with a 7-point mosaic and the ACA to obtain data with a resolution of about 450 AU and sensitive to structures extending up to about 0.1 pc scales, ideal for studying the properties of both outflows and envelopes. Combining the proposed observations with radiative transfer models, we aim to: 1) determine the importance of outflows in the removal of dense gas around protostars and its effect on the core-to-star efficiency; 2) establish how infall and outflow rates change of over the lifetime of prototstars and understand their effect on the core mass-loss process at different evolutionary stages; and 3) use the results to develop an empirical model of the evolution of the mass-assembling process of low-mass protostars. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2021-01-04T00:00:00.000 |
| 1488 | 2015.1.01359.S | 4 | Investigating the feeding of a baby radio galaxy | Young radio AGN are very suitable objects to study the role of molecular gas in the triggering and fuelling mechanisms of AGN. They are rich in cold gas close to the active nucleus and often show a strong interplay between the cold gas and the radio plasma, such as gas inflows and outflows. Such AGN-ISM interactions are thought to play a crucial role in galaxy evolution. We propose ALMA observations of the closest gas-rich young radio AGN PKS1718-649 (D=62 Mpc). It is a newly born radio AGN where, very close to the AGN, the atomic and the molecular hydrogen show highly disturbed kinematics, indicative of a strong on-going interaction with the radio source. Because of its proximity, we can study at high resolution (60 pc) the kinematics of the cold molecular gas (CO v=0 2-1) with ALMA. We will be able to separate the different kinematic components in the very inner regions, disentangle the complex geometry of the cold gas and identify what is contributing to fuel the radio AGN. This will provide a unique opportunity to analyze in detail the physical mechanisms of the complex interplay between a newly born radio AGN and its surrounding interstellar medium. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-12-16T13:58:27.000 |
| 1489 | 2016.2.00015.S | 55 | Debris Disk Structure Around Nearby Sun-like Stars with the ACA | We have assembled resolved millimeter continuum observations of a sample of the eight brightest debris disks around the closest (<20 pc) Sun-like (FGK) stars using ALMA. These data will allow us to (1) quantify surface density structures and address the basic dynamical processes that govern debris disk evolution to Gyr ages, (2) place constraints on otherwise inaccessible wide-separation planets in these systems from signatures of planet-disk interaction, and (3) make the first systematic comparative study of planetesimal structures around Sun-like stars. Several targets were observed with ALMA in previous cycles with archival data available, and we received data for all of the remaining targets during Cycle 4. While the majority of sources are well-detected, three targets are missing ciritical data at short baselines. We propose ACA observations of HD 207129, HD 38858, and HD 115617 to complement existing ALMA datasets and better characterize the planetesimal distribution in these debris disks. Completion and analysis of this nearby sample will provide a benchmark for interpretation of the large population of more distant systems. | Debris disks | Disks and planet formation | 2018-06-01T20:45:56.000 |
| 1490 | 2021.1.01183.S | 3 | Resolving the magnetic field in the torus of NGC1068 | ALMA has measured a ~10 pc-scale magnetic field in the dusty molecular torus of NGC 1068, whose structure and strength suggest to be the signature of a magneto-hydrodynamical (MHD) inflow. Subarcsecond infrared polarimetric observations have shown that the polarization from the inner edge, ~0.4 pc, of the torus is dominated by magnetically aligned dust grains in a wind. These studies suggest that the origin, evolution, and morphology of the torus can be explained as a MHD inflow/outflow model. Quantify that the B-fields are present at all scales in NGC1068's torus is required to confirm/reject the MHD outflow/inflow model. This proposal aims to obtain the pc-scale B-field in the torus of NGC 1068 using continuum linear polarization in Band 7 at an angular resolution of 0.029(1.7 pc). The measured B-field orientations will quantify whether B-fields are indeed good tracers of the gas flows towards the active nuclei or are entangled due to internal turbulence or complex dynamics in the torus. The computed B-field strength will compute the modified beta-plasma parameter to disentangle the dominant physical mechanism in the torus to put constraints in the the MHD outflow/inflow models. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-04-20T17:55:21.000 |
| 1491 | 2013.1.00433.S | 8 | Characterizing the nature of a protogalaxy in the primordial Universe (z=7.1) seen by ALMA | In our previous Cycle 1 observations we have detected [CII]158um emission in a star forming galaxy at z=7.1, well within the epoch of reionization. This is the most distant [CII] detection and in a galaxy representative of the galaxy population responsible for the reionization of the Universe. The [CII] line is extremely narrow (8 km/s) and slightly offset (a few kpc) relative to the Lya emissiion; both these features are in very nice agreement with the expectations for the distribution of ionized and cold gas from simulations of primeval galaxies. The system has a modest star formation rate (less than 10 Msun/yr), indeed in the range expected for galaxies contributing to the Universe reionization. The goals of the proposed observations are 1) to map the [CII] emission with much higher angular resolution and verify the expectatinos of models that [CII] should break up into small clumps with sizes of ~1 kpc; 2) obtain a detailed dynamical map to infer the mass distribution of the system; 3) trace the ionized component of the ISM through the [OIII]88um line, which is not affected by IGM absorption, and which is expected to have a smoother and broader distribution than [CII]. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2016-07-20T00:00:00.000 |
| 1492 | 2016.1.01398.S | 108 | The role of the environment in shaping the CMF in the L1641 Molecular Clouds | We propose to use the C40-1 12-m array configuration in band 3 to observe 12 pre-stellar cores across the L1641 molecular clouds to derive their physical properties with regards to their local environment. Specifically we want to determine whether their formation and subsequent evolution on a filament or in the field affects the ongoing star formation process therein in any way. We will use the HCO and H13CO+ J=1-0 emission line to detect the infall motions within the cores as well as those from the local environment onto the cores and study any variations in the infall rate. We will further use the SiO (J=2-1) emission line to look for outflows towards these cores, indicative of very young proto-stellar sources and to fully characterise along with the infall motions the internal structure and dynamics the cores. We will further use the NH2D to trace the denset regions of the cores and derive their temperature and column density while the continuum emission will allow us to study the fragmentation level of the cores. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-05-12T00:37:58.000 |
| 1493 | 2018.1.01409.S | 146 | ALMA census of the most optically-dark massive galaxies at z~>4 behind lensing clusters | Deep surveys with the HST have greatly enriched our knowledge of the distant universe by discovering thousands of UV-bright galaxies at z>4. Recent studies, however, have found a new population of extremely red galaxies which remain undetected even in the near infrared (IR) with deepest HST imaging. It has been shown that most of these "HST-dark" galaxies are likely the most massive galaxies at z>4 with a mean IR luminosity of LIR~2x10^12Lsun, which is still unreachable with the current submillimeter wide-area surveys. Measuring their IR luminosity individually will put important constraints on the density of normal dusty star-forming galaxies beyond z=4 and stellar-mass function at massive end. Here we propose an ALMA census of the "HST-dark" galaxies selected in the cluster lensing fields, which is essential to confirm individually whether they are dusty star-forming galaxies at high redshift. Most importantly, we propose spectral scans towards two brightest sources detected at 850 micron from our pilot SCUBA2 ultradeep imaging, to confirm their redshifts, which is otherwise impossible even with the next generation optical telescopes such as ELT. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2020-08-24T05:28:37.000 |
| 1494 | 2019.1.01707.S | 5 | RESOLVING THE TWIN DISKS IN THE FU ORI SYSTEM: Episodic accretion via binary interactions? | FU Ori objects are low-mass pre-main sequence stars characterized by dramatic outbursts of several magnitudes in brightness, which are not yet well understood. The archetypical FU Orionis system is composed of two young stars with a projected separation of 0.5''. Gas and dust emission have been detected around both components in previous observations. The dust emitting regions have not been resolved until now. Using ALMA, we resolved both the primary and secondary components into disks of only 11 AU in radius. The 1.3 mm emission, although only marginally resolved, yields inclination angles for each compoenent. The twin disks are near co-planar. We also found evidence of Keplerian rotation in the primary from CO kinematics. Most interestingly, we found a kinematic counterpart to a large arc-like feature previously known from scattered light. Whether this feature is infalling (accreting) or outflowing (original outburst?) is a key question we aim to address by increasing the resolution of our observations by a factor 3. The proposed observations will test for structure in the disks, as well as obtaining deeper kinematics to shed light on the mistery behind FU Ori outbursts. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2022-10-26T22:53:02.000 |
| 1495 | 2013.1.00458.S | 2 | Last equatorial flows in axial PNe, effects of a binary stellar system | Studying the appearance and properties of bipolar winds is critical for understanding the stellar evolution from the AGB to the planetary nebula (PN) phase. Many uncertainties exist regarding the presence and role of binary stellar systems. M 2-9 is a young PN with very elongated bipolar structure, that singularly yields direct information on its central stellar system. In the equator, rings detected in molecular line emission show unprecedented positional and dynamical imprints of the presence of a binary system. From those, a mass ~< 0.2 Msun was proposed for the companion of the central post-AGB star. If the presence of such low-mass companions can trigger the shaping of very elongated lobes, this would strongly supports the binary-based models. Here we propose to observe 12CO J=3-2 and 6-5 line emission to dig more deeply into the peculiar kinematics identified in the equatorial rings in M 2-9, and thus better characterize the properties of the binary system. We want to study in detail the excitation conditions of these last winds, the suggested presence of shock dynamics, and of inner warmer components, and the relation between the bipolar outflows and the equatorial rings. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2016-08-09T11:17:01.000 |
| 1496 | 2016.2.00133.S | 1093 | Redshifts of bright Herschel ATLAS gravitational lenses | We propose CO redshift measurements of 30 of the brightest (S500m > 0.1 Jy) strongly gravitationally lensed galaxies from the equatorial and Southern fields of the Herschel Astrophysical Terahertz Large Area Survey (HATLAS). These simple observations will double the sample size of H-ATLAS background source redshifts, complementing our long-term 8m-class foreground lens redshift campaigns. Our pioneering lens selection (Negrello et al. 2010 Science) has an astonishing ~100% efficiency and the gravitational amplification makes CO line detection up to ~100× faster than in unlensed surveys. Our proposed redshifts will provide spectroscopic confirmation of gravitational lensing, by finding submm redshifts that are clearly higher than the redshifts of the lensing masses. This on its own is already enough to make statistical constraints on the dark matter halo profiles. Combined with our ongoing multi-wavelength campaigns, we will start placing direct constraints on the evolving dark matter distribution of the lenses. The joint lenssource redshift distribution is a key discriminator of cosmological parameters and the evolution of dark matter haloes. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-12-26T12:22:50.000 |
| 1497 | 2016.1.01423.S | 68 | Probing the star forming nature and co-evolutionary relations of low-luminosity quasars at z >~ 6 | Previous studies of the properties of galaxies hosting quasar nuclei and the so-called co-evolution at high redshifts were strongly biased towards very luminous quasars, that prevents us from understanding the general picture of the growth of supermassive black holes (SMBHs) in the early universe. With this in mind, we here propose submm follow-up observations of recently identified quasars at z ~ 5.9-6.4 by our on-going deep optical survey with the Hyper Suprime-Cam on the Subaru telescope. These quasars are very unique as they are on average ~10 times fainter than luminous z~6-7 quasars at submm (e.g., J1148+5251). With this 12.2 hr program, we aim at detecting the [CII] line and the underlying FIR continuum emission of four low-luminosity high-z quasars. We will assess dust mass, gas mass, and SFR of the hosts, and compare these quantities with those of luminous quasars at comparable redshifts. The star forming nature as well as [CII] velocity dispersion will let us investigate the co-evolutionary relationship between the properties of host galaxies and SMBHs in a less-biased way. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2018-02-13T22:15:45.000 |
| 1498 | 2022.1.00916.S | 60 | Revealing the molecular gas content of low-metallicity low mass strongly lensed galaxies | In the past decades, studies of massive high-z galaxies have revealed a strong relation between molecular gas and the rates and timescales of star formation. When exploring the lower mass range with, the help of gravitational lensing, galaxies have appeared to have less gas and/or to use their gas more rapidly than expected . This apparent gas deficit (relative to massive galaxies) can either be due to the systematic uncertainties of tracer-to-gas calibrations or to a fundamentally different mode of star formation taking place in these lower mass galaxies, but testing this can only be addressed with larger samples. Here we propose CO and dust continuum observations with ACA of six low-mass strongly-lensed star-forming galaxies at z~2-3. These observations will significantly expand the current sample of gas measurements in such objects, with the goal of improving statistics to confirm (or discard) the observed deficit. Additionally, by using two independent tracers we address some of uncertainties of tracer-to-gas calibrations. Finally, ACA and its large FOV and beam sizes is the best suited instrument to perform this survey. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2024-07-25T16:39:47.000 |
| 1499 | 2019.1.01600.S | 756 | A complete census of spectroscopic redshift of 850 micron selected high-redshift HyLIRGs | Submillimeter galaxies (SMGs) that are brighter than 10 mJy at 850 micron have a total infrared luminosity greater than 10^13 solar luminosity, analogous to the neaby hyper lunimous infrared galaxies (HyLIRGs). They host sites of the most intensive star formation at high redshifts (z>1), yet due to a lack of a homogeneous sample our understanding toward this population is still limited, and models have made vastly different predictions on their properties. We have recently completed a band 7 ALMA follow-up survey of a flux-limited sample of single-dish selected submillimeter sources, detecting 50 SMGs with >10mJy flux density, representing one of the largest high-redshift HyLIRG samples. Here we propose to conduct a band 3 spectroscan on 18 SMGs with >13 mJy, aiming to 1) measure a complete redshift distribution of a flux-limited HyLIRG sample and study their ISM through CO, 2) to test the prediction of the fraction of SMGs being strongly lensed, and 3) to provide limits on the fraction of physically associated pairs on targets with closeby SMG companions. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-05-06T14:34:15.000 |
| 1500 | 2023.1.01064.P | 0 | Hunting for pulsars orbiting Sgr A* | With the presence of the closest supermassive black hole to Earth, Sgr A*, the center of our Galaxy is an excellent and unique laboratory for experimenting with gravity. In particular, discovering even one single pulsar in orbit with Sgr A*, will provide an unprecedented opportunity to test the fundamental predictions about the nature of black holes. The mass, spin, and quadrupole moment of Sgr A* could be measured with high precision, by carefully tracking the pulsar over the course of its orbit. These measurements can be combined with event-horizon-scale imaging of Sgr A* and orbital dynamics of the S-stars, yielding a full mapping of the space-time in the vicinity of Sgr A*. Here, we propose to use the phased ALMA in Band 1 to perform the deepest search for pulsars in orbit with Sgr A* at mm-wavelengths. The new search will greatly elevate the chance for a detection compared to previous searches, providing the best opportunity by far to find a new pulsar in the Galactic Center at mm-wavelengths. It will also largely improve our capability of gauging the mysterious pulsar population in the Galactic Center, which is potentially large but so far remains mostly unseen. | Pulsars and neutron stars | Stars and stellar evolution | 3000-01-01T00:00:00.000 |
| 1501 | 2013.1.00806.S | 15 | Needles in the Cosmic Haystack - A Hunt for Massive Starless Cores | Massive star formation remains an important unsolved problem in astrophysics. Better observational constraints on its initial conditions are needed. Very few good examples of massive starless cores are known that are on the verge of star formation, i.e. scaled-up versions of highly-deuterated, centrally-concentrated low-mass pre-stellar cores. After searching four infrared dark cloud (IRDC) clumps with ALMA in Cycle 0, we detected one bona fide example in N2D+(3-2) (Tan et al. 2013). The source, C1-South, has a booming signal in this emission line. Here we propose an efficient survey of 32 more IRDC clumps to find more massive starless cores: we expect this will yield a sample of about 10 such cores, the beginnings of a statistical sample. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-05-27T01:00:25.000 |
| 1502 | 2022.1.01413.S | 8 | Filament fragmentation in high-density environments | Filaments have been studied widely in mm and sub-mm regimes (e.g. Herschel, ALMA). In environments with densities ~1E4 cm-3, the fragmentation process occurs quasi-statically, leading to the formation of equally spaced cores that inherit the kinematic properties of the parental filament. Orion A is the closest high-/intermediate-mass star-forming region, a perfect laboratory to study star birth in a high-density environment. The most compact filaments reported in this region show unprecedented high densities of >1E7 cm-3. These filaments also show extremely narrow widths marginally resolved at the current interferometric resolutions. While multiple cores are found in these high-density filaments, the fragmentation mechanism in these environments remains under debate. The project aims to investigate this fragmentation in Orion A using the extended configuration C43-4 of the ALMA 12m-array in order to achieve an angular resolution of 1" (~400 AU at ~400 pc). Using the N2H+(1-0) (Band 3) emission to trace the dense gas, we aim to resolve the velocity-coherent filaments and cores in the OMC-1 region and characterize the core formation process in this high-density environment. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-05-22T11:10:03.000 |
| 1503 | 2019.2.00236.S | 10 | Mapping NGC253 in dense gas tracers with ACA | We propose to use the 7m+TP ACA to map dense gas tracers in bright nearby starburst galaxy NGC253 (3.5Mpc). We will target the brightest lines in 3mm band that trace dense gas (e.g. HCN, HCO+, HNC etc) at 15 arcsec resolution (spatial scale 200pc) to characterize dense gas properties over the scale that is several times better than previously achieved over the central 3kpc disk of NGC253. This source has been actively studied by other facilities in the past few years which gave us various ancillary observations within a large range of wavelengths. With these observations, we will be able to address several open science questions, including 1) how does the dense gas fraction relate to environment and star formation efficiency on ~200 pc scales? 2) how are the dense gas properties linked to the turbulent pressure? Answering these is fundamental to our understanding of star formation within dense gas from galactic down to molecular cloud scales. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2021-04-18T11:35:31.000 |
| 1504 | 2018.1.01242.S | 20 | Fragmentation of Serpens FIRS1: a Class 0 protostellar disk | Protostellar disks are formed as a natural consequence of conservation of angular momentum during star formation. They are the cradle of both stars and planets. A fragmenting protostellar disk may cause short accretion bursts, form a stable stellar or planetary companion around the central star, or even produce massive exoplanets. Observationally, its a challenge to identify and observe a good candidate that meets the requirement for disk fragmentation. Serpens-FIRS1 is one of the few known intermediate mass protostar that has a protostellar disk massive enough to meet the requirement for disk fragmentation. We propose to observe the young, Serpens-FIRS1 Class 0 protostar in Band 3 continuum and line emissions 13CO, C18O, C17O and CN (1-0) in order to measure the physical properties of a young disk that is expected to be fragmenting, identify whether or not it has a Keplerian rotation, and constrain the mass of the central protostar. With the direct observation we will test the existing theories of protostellar disk fragmentation. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2019-11-15T19:12:42.000 |
| 1505 | 2017.1.00595.S | 325 | DEATH STAR: DEtermining Accurate mass-loss rates of THermally pulsing AGB STARs | Mass loss by a stellar wind is a decisive process for late stellar evolution. Through this wind, Asymptotic Giant Branch (AGB) stars are major contributors of synthesized elements and dust to their surroundings. The wind process is studied using dynamical wind models with the goal of developing a predictive theory of AGB mass loss crucial for stellar and galactic evolution. The most reliable method to measure mass-loss rates, and to provide constraints for the wind models, is through CO line observations, but further progress in this fundamental field is still limited by the large observational uncertainties, where the assumed size of the CO envelope is a major factor. To solve this problem we propose to directly measure the CO envelope sizes for a representative sample of typical AGB stars by observing the CO(2-1) and (3-2) emission using the ACA in stand-alone mode. With this data we will develop the most accurate description of AGB mass loss, needed over a large range of wind properties, uniquely determine the gas-to-dust ratios of the sources, and through the large bandwidths covered in band 6 and 7, provide a goldmine for legacy science for the evolved star science community. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-07-09T08:47:48.000 |
| 1506 | 2015.1.01332.S | 87 | Radiatively-Driven Implosion in the Trifid Nebula | The model of Radiatively-Driven Implosion (RDI) successfully accounts for the presence of long-lived, photoionized molecular cores in the vicinity of young massive stars. RDI predicts taht the stellar radiation drives the propagation of an ionization front preceded by a convergnet shock front and a photon-dominated region into the neutral gas. This scenario is actually incomplete. Observational, quantitative comparisons are lacking: the nature of the IF remains to be established, depending on the radiation field. Important dynamical interactions at the interface between the neutral and ionized gas are neglected, while they can strongly affect the cloud evolution and the conditions of star formation. The many Cometary Globules discovered in the young Trifid nebula (M20) allow us to tackle these issues. We propose to lead a comprehensive study of two of them, in order to determine their physical and chemical structures from the central star-forming core to the surface layers, where signatures of instabilities are observed. Comparison of their properties will unveil the role of the radiation field on the physical and chemical evolution of the molecular gas. | Inter-Stellar Medium (ISM)/Molecular clouds, HII regions | ISM and star formation | 2017-07-19T18:50:48.000 |
| 1507 | 2016.1.00281.S | 6 | Imaging the Molecular Gas Outflow from Gravitationally Lensed QSO MG 0414+0534 in 20 pc Resolution | Quasi-stellar objects (QSOs) are one of the most energetic sources in the early universe, and therefore the outflows from these objects are efficient metal enrichment sources at that time. However, it is not clear whether radiation (radiative feedback) or jet (mechanical feedback) is the dominant mechanism of the QSO outflows. We observed a gravitationally lensed QSO MG 0414+0534 in ALMA Cycle 2, and detected a broad (~1800 km/s) CO(J=11-10) line at a spatial resolution of ~0.3" (~150 pc). Since the CO line transition is high and the velocity width is much wider than that of the typical galactic rotation (a few hundred km/s), we consider this as the detection of a molecular gas outflow from a QSO. Since this QSO has radio jets with the size of 0.10"-0.15", imaging the molecular gas outflow with higher angular resolution and find out whether it is nearly isotropic (outflow due to radiative pressure) or bipolar (outflow due to radio jets) will tell us the dominant mechanism of the QSO outflow for the first time. We therefore request long baseline observations with the spatial resolution of 0.037" (~20 pc) at Band 7 in the CO(11-10) line. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2019-02-02T20:06:29.000 |
| 1508 | 2021.1.01644.S | 59 | Probing the Excitation and the Mass-Luminosity Conversion Factor of the Dense, Star Forming Gas Across Galaxy Disks | We propose ACA Band 6 observations to map the J=3-2 line emission of the canonical, extragalactic dense gas tracers HCN and HCO+ in 9 nearby disk galaxies. The target fields cover a broad range of environmental conditions. Our main goal is to constrain the excitation and, more generally, the physical conditions of the dense, star forming gas across disks. In external galaxies, such studies were largely focused on bright galaxy centers or (U)LIRGs at low, kpc-scale spatial resolutions or in very compact nuclear regions. This proposal will multiply the number of galaxies and range of environments at sub-kpc scales. Our ultimately goal is to link: (1) the excitation conditions of the dense, star forming gas; (2) the cloud properties derived from physically-motivated radiative tranfer modelling; (3) and the environment the clouds live in. Further, line ratios are essential to constrain the HCN conversion factor from which dense gas masses are derived. We will revisit the scaling relations between dense gas and star formation that help us differentiate between competing models for how star formation is regulated across galaxies. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2024-06-27T08:40:26.000 |
| 1509 | 2016.1.00171.S | 790 | Understanding ISM physics at high-z: cold gas and CO excitation for 75 normal and starburst galaxies at 1.1<z<1.7 | We propose to observe CO[2-1] for 75 galaxies with ALMA Cy3 measurements of CO[5-4] and 500um rest-frame dust continuum (hence Mdust), and with secure LIR from Herschel (hence also Tdust), roughly evenly divided between main sequence and starburst galaxies, towards the SFR density peak at 1.1 | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2018-02-11T15:57:28.000 |
| 1510 | 2023.1.00905.S | 0 | HII Regions and Galactic Chemical Evolution | The present-day chemical structure of the Milky Way disk constrains models of Galactic chemodynamical evolution. HII regions, the sites of recent massive star formation, are a bright trace of Galactic metallicity structure. Galactic disks are expected to be well-mixed, but recent observations of HII regions in the Milky Way and other galaxies have revealed unexpected azimuthal variations in the metallicity structure of these galaxies. Several competing theories have been suggested to explain these observations. We propose to observe isotopologues of CO and CN with the ALMA Compact Array (ACA) toward molecular gas associated with HII regions across the Galactic disk. We will use these data to derive 12C/13C isotopic ratios, which, when compared with the metallicities of the associated HII regions, will allow us to distinguish between the competing theories for the azimuthal metallicity structure. We will simultaneously derive 14N/15N and 16O/18O isotopic ratios, which further constrain models of Galactic chemical evolution. | HII regions | ISM and star formation | 2025-08-30T22:48:52.000 |
| 1511 | 2015.1.00453.S | 18 | [HCN]/[HNC]: A fundamental problem in Astrophysics | The two isomers of the H-C-N system, hydrogen cyanide (HCN) and hydrogen isocyanide (HNC), are commonly used as tracers of the dense molecular gas in Galactic and extra-galactic research. Moreover, the [HCN]/[HNC]is considered as a chemical diagnostic for the gas temperature. The full comprehension of the HCN and HNC chemistry is therefore of paramount importance in the study of the physics and chemistry of the interstellar gas. In the latest years, gas phase and gas-grain chemical models have increased in complexity and incorporated new laboratory measurements to provide an accurate and complete description of their chemistry. However, high spatial resolution and high sensitivity data are needed to test these models. Based on our IRAM 30m 2D spectral survey, we have measured an anomalously high [HCN]/[HNC]ratio (larger than 10) towards the ultracompact HII region Mon R2. Time dependent effects and photodesorption have been proposed as possible explanations. Our goal is to determine the [HCN]/[HNC] ratio at a spatial resolution of 1-arcsec in order to discern between these two interpretations and investigate the influence of UV photons on the chemistry of the H-C-N system. | Astrochemistry | ISM and star formation | 2018-04-11T02:09:21.000 |
| 1512 | 2018.1.01301.S | 42 | A Survey for CO(3-2) in HS1549+19, the most overdense protocluster known at z>2 | We propose to map the HS1549 z=2.85 protocluster in the CO(3-2) line. HS1549 is amongst the richest system in Lyman-break galaxies and Lyman-alpha emitters at z>2 known. We choose 35 pointings which cover all highly significant SCUBA-2 sources lying within high density subregions in the protocluster (likely cosmic web "nodes"), and the intervening area covered by the 70 band-3 ALMA primary beam. Our pilot NOEMA pointing targeted an especially active subregion, with 4 QSOs and 3 bright submm sources. We detected 6 sources in CO(3-2), but cannot easily interpret the results more globally in terms of galaxy density and CO luminosity function. This ALMA program will provide an efficient view of the star forming gas in a massive protocluster to understand the assembly of one of the richest regions in the Universe, but also as a lever on the CO(3-2) luminosity function and its variations within the protocluster, scaled by the galaxy density in this system. This is a resubmission of a C-rated cycle 4 proposal which has not received any data yet. The proposal has been updated, to include our wider field SCUBA-2 map over the Subaru mapped extended pro cluster. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-01-22T16:29:03.000 |
| 1513 | 2018.1.01240.S | 13 | Mapping the molecular gas reservoir of a recently-quenched galaxy | Our ALMA survey of massive z~0.6 post-starburst galaxies has revealed that recently-quenched galaxies can retain significant- and puzzling- molecular gas reservoirs. Our detection of >10^10Msun of gas in SDSS J0912+1523 represents the first detection of molecular gas in a quenched galaxy outside of the local universe, and indicates that quenching does not require the total removal or depletion of molecular gas. However, we still do not understand the physical processes preventing this abundant gas from forming stars. Here we propose follow-up observations of this galaxy to map its gas distribution and velocity structure using high-resolution CO(2-1) data, and to probe the gas density using CO(4-3) data. These observations-- in conjunction with the stellar kinematics, 1.4 GHz continuum, and high-resolution imaging we have obtained for this target-- will allow us to assess the gas density, compare the stellar and gas morphology and kinematics, search for signs of merger activity or outflows, and place this galaxy on the Kennicutt-Schmidt relation. This analysis will help constrain the physical mechanisms that quenched star formation in this galaxy without depleting the molecular gas. | Galaxy structure & evolution | Galaxy evolution | 2020-02-16T17:55:18.000 |
| 1514 | 2015.1.01495.S | 80 | Are the most massive z >4 galaxies hidden from HST ? | Our current understanding on the cosmic star formation history at z > 4 is primarily based on UV-selected galaxies. A critical question is then whether we are missing a significant population of massive, UV-faint galaxies. By crossmatching HST/WFC3 and IRAC data in the three CANDELS-Herschel fields, we perform a systematic search of galaxies which are bright in IRAC but are not detected in the WFC3 H band, i.e., H-dropouts, which are likely at z > 4 where the H band probes the rest-frame UV. In total, we identify 64 H-dropouts down to [4.5] < 24, corresponding to M*~10^{10.8} Msun at z > 4. Both photometric redshifts and stacked infrared SED suggest that most of them are at z > 4, with LIR~2*10^{12} Lsun. These galaxies likely represent 30-40\% of the most massive galaxies at z > 4, but were completely missed in previous studies based on either UV or near-infrared selected samples. An ALMA 870 um census is crucial to confirm individually that they are high-redshift dusty sources, and explore star formation properties for this unique sample, which is essential to have a complete understanding of massive galaxy formation in the first 1.5 Gyr of the universe. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-12-12T17:50:43.000 |
| 1515 | 2017.1.01545.S | 230 | The first molecular line inventory in hybrid disks | The transition from the late phase of protoplanetary disks to young debris disks remains a poorly explored evolutionary stage of planet-forming disks. The new class of "hybrid" disks, recently revealed by our team, includes disks exhibiting debris disk-like dust properties, but having primordial gas content. These disks may represent the protoplanetary to debris disk transition. In order to establish how the physical and chemical properties evolve, we propose to study all four hybrid disks discovered so far, and four evolved Herbig Ae systems with relatively low gas content as comparison targets. The observations will provide the first inventory of the most important molecules in these disks. We will characterize their morphology and kinematics, and perform a detailed chemical analysis using our ANDES and ALCHEMIC chemistry codes adapted to these disks. Our program will reveal the physics of an independent evolutionary path for the gas component around A-type stars. The longer than anticipated survival of gas in hybrid disks will have important consequences for planet formation, providing material for the formation of gaseous planets even after the canonical 10 Myr of evolution. | Debris disks | Disks and planet formation | 2019-07-16T19:50:00.000 |
| 1516 | 2011.0.00340.S | 0 | Searching for H2D+ in the disk of TW Hya v1.5 | Most of the mass in a protoplanetary disk is represented by molecular gas concentrated near the midplane, but it is exceedingly difficult to find clear signatures of gas in such locations. Emission lines from deuterated species like H2D+ and D2H+ provide the best - and perhaps only - diagnostics for probing gas in the disk midplane, and thereby learning about the local kinematics and ionization fraction. We propose to search for the ortho-H2D+ 372.421 GHz line toward the well-studied, nearby disk around TW Hya with the "compact" configuration. The proposed observation will allow us to detect ortho-H2D+ fractional abundances down to 30 mJy km/s, more than an order of magnitude below present upper limits. This corresponds to ortho-H2D+ fractional abundance of 1e-13 which is below any published model predictions. A detection will constrain the ionization fraction in the cold disk midplane and help probe the gas kinematics and the viability of MRI-based disk transport physics in this region of the disk. A non-detection will challenge the existing models, helping improve our understanding of accretion flows in the disk midplane. | Disks around low-mass stars, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | Disks and planet formation | 2013-12-06T19:55:00.000 |
| 1517 | 2019.1.01408.S | 6 | Unveiling the formation scenario of born-again PNe through ALMA observations | Born-again planetary nebulae (PNe) are thought to be evolved objects that have experienced a very late thermal pulse (VLTP) when the central star was on the white dwarf track. The VLTP event produces an ejection of processed H-deficient material that interacts with the old PN. Optical and IR studies suggest that the evolution of the H-deficient material is fast with timescales of ~20-100 yr. Thus, these objects offers the possibility of studying the formation and evolution of dust and molecules in human timescales. We propose to study the spatio-kinematic properties of the youngest born-again PNe in which molecular emission has been detected but not resolved. Our observations will bring insights in the early formation of non-isotropic ejections in evolved stars and will constrain the current formation scenario of born-again PNe. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2022-07-27T14:57:14.000 |
| 1518 | 2017.1.00255.S | 563 | Revealing the internal structure of molecular outflows: spatially resolved observations in local LIRGs | Massive gas outflows, produced by AGN and star-formation (SF), play a major role in the regulation of the stellar mass and central black-hole mass growths. They are ubiquitous in galaxies with strong SF and AGN, but little is known about the physical processes that control their evolution and impact on the host galaxy. We propose to address this issue by obtaining high-spatial resolution (60 pc) CO(2-1) observations for a representative sample of 18 (15 new + 3 archive) local LIRG systems (22 individual galaxies) known to host outflows. We will resolve the clumpy internal structure of the molecular phase of these outflows, and, together with our knowledge on the ionized and neutral atomic phases available from ancillary integral field spectroscopy data, we will be able to investigate the key aspects that define the structure and evolution of outflows: (i) mass, kinetic energy, and momentum evolution of the molecular gas within the outflow; and (ii) impact of possible SF occurring within the outflow through the extra injection of energy and momentum. With this proposal, we will overcome the statistical limitations of previous studies based on just a few cherry-picked galaxies. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2019-04-20T14:29:53.000 |
| 1519 | 2015.1.00139.S | 4 | Where is the cometary chlorine? | We propose a new probe of cometary ice evolution in protoplanetary disks: chlorine. Its chemistry in molecular gas is well known, and the main carrier HCl easily observed. The journey of chlorine from ices in protostellar cores to comets is currently a puzzle. Comets yield upper limits on their HCl to H2O ice ratio of order 0.0001, while protostar studies infer values an order of magnitude higher. It is not known whether the HCl ice evaporated in the protoplanetary disk, or was converted and locked into some unknown ice species. The answer lies in the gas-phase chlorine abundance in disks. We will use ALMA observations of HCl in a young Solar System analog to determine whether chlorine in disks has returned to the gas, as suggested by cometary ices. This study is timely, as the Rosetta spacecraft at comet 67P will soon provide the strongest constraint to date of the HCl to H2O ratio in a comet. | Disks around low-mass stars, Solar system - Comets | Disks and planet formation | 2017-10-21T01:33:08.000 |
| 1520 | 2011.0.00319.S | 0 | Low luminosity millimeter survey behind a strong lensing cluster | We propose to perform continuum observations at 1.3 mm (Band 6) in the strong magnification region (x > 10) of the massive cluster Abell 1689. We can cover a survey area of 4 arcmin2 down to an intrinsic (lensing-corrected) sensitivity of 0.05 mJy (4sigma). We expect to detect ~ 12 continuum sources according to current models. This will allow us to complement the studies of brighter continuum sources and derive their relative contribution to the star-formation rate and cosmic infrared background. At the same time, we will measure the CO line flux of 3 submm galaxies at z=2.5-2.7 discovered with SCUBA in this field, and we will cover the wavelength of the CO line for a sample of 30 other sources at 2.5 | Gravitational lenses, Sub-mm Galaxies (SMG) | Cosmology | 2013-09-07T11:37:41.000 |
| 1521 | 2019.2.00062.S | 61 | Unlocking the Potential of the Most Definitive Molecular Tracer of UV-Enhancement: l-C3H+ | The recently-discovered interstellar molecule l-C3H+ appears to be the most sensitive and definitive molecular tracer of enhanced UV-flux ever observed in the ISM. Extensive, deep searches for this species in dozens of sources show its presence exclusively in UV-enhanced regions. Yet, our understanding of the spatial distribution of the molecule within these sources, and the excitation conditions (and abundances) in previously-observed regions, is sorely lacking. Here, we propose ALMA observations following up on our prior ALMA detection of l-C3H+ in the Horsehead PDR region. Our 12m observations revealed an unexpected large-scale distribution of l-C3H+ which is clearly missing short spacing data which the ACA can provide. We also request follow up observations of Mon R2 which shows no compact structure and thus requires ACA data to reveal extended emission. We wish to better understand the spatial distribution, abundance, and excitation of this potentially transformational molecule in our ability to probe the extent of UV-enhanced flux in these and other key regions. The results will be used to refine state-of-the-art PDR chemical modeling codes and inform related ALMA proposals. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2022-09-29T21:48:09.000 |
| 1522 | 2017.1.01117.S | 56 | Study of the first O-type 'bloated star' candidate | 'Bloated stars' are high-mass young stellar objects whose stellar surface is expanding due to active accretion on to them. While this phase of massive star formation is firmly predicted by models, no clear examples of O-type stars have been identified yet in such a phase. IRAS 19520+2759 is, to our knowledge, the best 'bloated star' candidate with a luminosity > 10^5 Lsun, given its particular optical spectrum, lack of radio-continuum emission, its association with collimated outflow, and with an elongated, dense structure likely tracing a rotating structure perpendicular to the outflow. However, the association of the millimeter dense core and the optical star remains to be confirmed, and here we propose 0.15 arcsec angular resolution observations of the continuum at 1 mm (comparable to Hubble Space Telescope 0.1 arcsec resolution in the optical) in order to determine the position and morphology of the mm source. Simultaneous spectral line observations of dense gas tracers will allow to study the kinematics of the gas in the vicinities of the first O-type 'bloated star' candidate. | High-mass star formation | ISM and star formation | 2019-10-12T09:41:44.000 |
| 1523 | 2021.1.00754.S | 14 | Dissecting the circumstellar disk around the B-type protostar IRAS20126+4104 | The existence of disk+outflow systems around early-type stars has been invoked by theorists to overcome the powerful radiation pressure by the star and allow the accretion onto the star to proceed up to 140 Msun. Despite their importance, only recently bona-fide disk candidates have been detected around B-type (>8 Msun) protostars. IRAS20126+4104 is by far the best of these. Both the close distance (1.64kpc) and the well studied disk+outflow system make this the ideal target for a high-resolution study with ALMA. With the proposed observations we will for the first time establish the rotation curve and disk physical parameters (temperature, column density) as a function of radius. Our observations will be a breakthrough, as little is known on the nature of the disks around B-type stars because the resolution attainable before ALMA was insufficient to properly resolve them. In particular, we will obtain the following: calculate the Toomre Q parameter as a function of radius and assess if the disk is stable, compute the stellar mass and accretion rate through the disk onto the star, and establish the presence of gaps and/or local instabilities, possibly induced by stellar companions. | High-mass star formation | ISM and star formation | 2023-07-21T22:15:21.000 |
| 1524 | 2019.1.00564.S | 11 | Enhanced Molecular Oxygen abundance in galaxies with AGN molecular outflow | We propose to observe red-shifted 118.75 GHz O2 emission as well as CO 2-1 toward one nearby AGN IRAS 10565+2448, in which molecular outflow had been detected with CO 1-0 observation. It will be the first well-imaged extra-galactic O2 emission, which will be an ideal tool for studying AGN feedback and understanding cooling and oxygen chemistry in molecular outflow. If O2 118.75 GHz line in IRAS 10565+2448 can be imaged within several hours, it will open a new window for searching molecular outflow in AGN, because outflows identified with CO observations can severely be contaminated by non-Gaussian components of the host galaxy. On the other hand, O2 emission from dense molecular gas in host galaxy can be neglected. If the enhancement of molecular oxygen in galaxies with AGN molecular outflow is a common phenomenon, such observations will be important to provide inforamtions of gas properties in O2 emiting regions for new chemical models of O2 formation. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-03-12T04:30:46.000 |
| 1525 | 2021.2.00077.S | 356 | Tending the Fire: A Survey of Molecular Gas Fueling in Powerful Nearby AGN | Despite 30 years of research, the role of cold, molecular, galaxy-scale gas in AGN fueling remains unclear. A large APEX survey of 213 of the brightest nearby (0.01 | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2023-05-24T20:46:29.000 |
| 1526 | 2018.1.01124.S | 3 | Resolving the SgrA* Accretion Disk at 2000 Schwarzschild Radii Using H30alpha Recombination Line | In our previous observations with ALMA Cycle 3 and Cycle 4, we detected a broad, 2000km/s wide H30alpha emission line from within 0.008pc of Galactic Center black hole (SgrA*). The H30alpha recombination line emission provides a direct and reliable probe of the non-X-ray emitting ionized gas likely constituting the bulk of the accretion reservoir of SgrA*. The double peaked shape of the detected line indicates the presence of a few 10^-3 * M_sun disk composed of ionized H at temperature ~10^4K. The emission is partially resolved and extends to just under 0.2'' in radius. We propose a high resolution study of the HI recombination line emitting disk around SgrA*. ALMA capabilities are such that it would allow us to resolve the disk down to the scale of ~2000 Schwarzschild radii. This observation would open up an entirely new avenue to understanding the black hole environment, allowing us to perform a direct measurement of gas kinematics and initiate a new observation-based modeling of the process by which the black hole is fueled. Both will be key to resolve the mystery of supermassive black hole accretion in the galactic center. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2021-04-30T00:00:00.000 |
| 1527 | 2017.1.00125.S | 17 | Quasar Feedback in the Early Universe: Lowest Eddington Ratio Quasar at z~6 | It has been found that quasars at z > 6 contain supermassive black holes (SMBHs) accreting mass at their maximal rates (Eddington ratio REdd ~ 1). However, it is suggested that their FIR emission is found to be unusually weak in comparison to their counterparts at lower redshifts, possibly due to a strong quasar feedback suppressing star formation in their host galaxies. Recently, we discovered a faint quasar at z ~ 6, IMS J2204+0112 with its REdd at only 0.07+-0.05. This finding suggests that there exist SMBHs with nominal accretion rates similar to lower redshift quasars, and that they may be a more general quasar population at z ~ 6. Here, we propose to study the FIR property of IMS J2204+0112, by performing the submm continuum observation at ALMA bands 6 and 7. ALMA is currently the only facility that can trace the faint FIR flux of J2204+0112 (expected to be 130 uJy) and the two band observation can produce a reliable estimate of FIR luminosity. The proposed observation will teach us for the first time how the star formation in host galaxies is linked to the black hole growth at z~6 for a quasar with nominal accretion activity. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-06-07T19:31:03.000 |
| 1528 | 2012.1.00453.S | 32 | Spatially resolved wide band spectroscopy in ULIRG obscured nuclei | The successful line surveys carried out at low resolution towards the prototypical ULIRG, Arp220, have unveiled an unexpectedly rich chemistry. Not only it has been shown that Arp220 is likely the brightest and most prolific molecular extragalactic emitter, but its chemistry appears to reveal significant differences with respect to that found in nearby starburst galaxies. The high sensitivity and resolving power of ALMA opens the possibility of spatially resolving the chemistry of the two nuclei. Such observations will shed light on the individual chemical composition and physical conditions of each nuclei. We therefore propose to extend the study of the molecular composition of Arp 220 by scanning the ALMA bands 6 and 7. Apart from the determination of molecular abundances, we will be able to determine the line contribution to the continuum emission and the cooling rate of the whole system. Moreover, we will get the most detailed study of the excitation conditions of the molecular gas in an ULIRG. | Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2015-07-23T12:00:44.000 |
| 1529 | 2019.1.00263.S | 77 | Explosive Outflows from Compact Groups of Forming Massive Protostars | The OMC1 explosion, ~0.1 pc behind the Orion Nebula, was powered by an N-body interaction that ejected 3 stars as runaways ~550 years ago. We propose to image three other candidate explosive protostellar outflows in molecules, H30-alpha, and the 1.3 mm continuum. They contain fingers of shock-excited molecular hydrogen, bullets, and streamers similar to Orion OMC1. Their radial velocity structure will determine if they were powered by a nearly instantaneous explosion or a quasi-steady injection of energy by winds or jets. Their masses, momenta, and kinetic energies, the locations of their source stars, and dynamical ages will be measured. Explosive protostellar outflows represent a new type of feedback in cluster-forming regions that may contribute significantly to the self-regulation of star formation. They are signposts of violent, N-body interactions or major accretion events. N-body interactions that eject stars from their birth environment by more than a few km/s will terminate accretion, set the final masses of the ejected stars, and if common, may play an important role in establishing the Initial Mass Function (IMF) of stars. This program will constrain the event rate. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2023-05-16T15:47:54.000 |
| 1530 | 2019.1.00700.S | 51 | Resolving water emission and dust temperature in the early universe | We propose spatially resolve dust temperature and infrared luminosity in three strongly-lensed starforming galaxies at z~3 from the SPT survey. With the aid of gravitational lensing, we will achieve kpc spatial resolution in the source plane in B9 with 0.5 arcsecond angular resolution. The B9 continuum observations will enable us to spatially resolve the L_H2O/L_IR correlation and dust temperature in galaxies at high redshift for the first time. These observations will provide a powerful constraint on the kinematics of the FIR field and help understand the relation between star formation and star formation potential at high redshift. The water observations have already been conducted in Cy 3 & 4 and the result has been published in ApJ. Here we are requesting 49 minutes in Band 9 to complete the continuum imaging portion of the project. (This exact proposal was given an A-ranking in Cycle 5, but never observed.) | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-03-13T22:28:53.000 |
| 1531 | 2018.1.01077.S | 0 | Unveiling the enigmatic gas content of distant starbursting mergers | The nature of high redshift galaxies with the highest specific SFRs (starbursts) is a lasting debate in the community. They could be very gas rich stream-fed objects, or very efficient star-formers, or a combination thereof. The debate cannot be solved unless reliable determinations of their alpha_CO and/or DGR ratio are obtained, allowing accurate measurement of gas masses of these systems that are mostly mergers. This could be only achieved via accurate determination of dynamical masses, a challenge for near-coalescence mergers. Our numerical simulations have shown that reliable dynamical masses can instead be obtained for interacting pairs, which retain their disk-like geometry, albeit with an intrinsic accuracy of ~0.2 dex. We propose to observe CO lines for 4 merging pairs at z>1.15 for which the total CO flux is already determined and strong. Together with another pair already in hand (Silverman et al 2018, submitted), these 10 galaxies will enable a statistical determination of the average alpha_CO and DGR in mergers to an accuracy of 0.1 dex. This will allow us to firmly determine dynamical masses in distant starbursts. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2021-01-07T15:02:39.000 |
| 1532 | 2018.1.01753.S | 16 | Detecting the envelope surrounding the HH30 T-Tauri star | We ask for ACA data to complement our ALMA-cycle 2 data-set on the T-Tauri star HH30 (see Louvet et al. 2018). HH30 is driving a bipolar jet, but a monopolar outflow. Our study of the outflow favors the models of MHD disk wind, that reproduce the best the parameters of the outflow. Nevertheless, we couldn't exclude that the outflow is created by a stationary interaction between the jet and the envelope of HH30. We were not able to detect the envelope with our ALMA-cycle 2 data and therefore request for a complementary larger-scale ACA data-set. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2020-01-07T12:19:29.000 |
| 1533 | 2021.1.00765.S | 0 | Physical Conditions of SSC Formation in Henize 2-10 | Super star clusters (SSCs) are consistent with being the progenitors of globular clusters, so understanding the conditions of their formation provides insight into star formation during the era of galaxy assembly. To understand the environment and conditions of SSC formation, it is essential to observe the earliest stages that are only observable at mm wavelengths, before stars form and disrupt the natal material. Johnson et al. 2018 identified a population of molecular clouds that may have the necessary properties to form SSCs in Henize 2-10, a dwarf starburst galaxy with several well-studied SSCs, but this data had too low a resolution to confirm them. This population includes clouds at a range of formation stages, including several with no associated thermal radio emission, indicating that massive star formation has not yet begun. Our proposed observations and non-LTE fitting technique will constrain the masses, sizes, temperatures, densities, substructure, and kinematics of these clouds. We will be able to confirm if this population has any pre-SSC clouds and compare the SSC formation process in a dwarf starbust to other environments, such as the major merger Antennae galaxies. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-10-21T17:07:56.000 |
| 1534 | 2019.1.00246.S | 152 | Moving Past Small Number Statistics in Astrochemistry: A Molecular Survey of 25 Hot Cores | Studies of chemical evolution have traditionally focused on a small number of exceptionally molecularly rich and bright sources due to the historical difficulty in detecting complex interstellar molecules. This small sample size biases our understanding of 'standard' chemical evolution, and prevents calibration of chemical models to standard conditions. Single-dish surveys that have attempted to address this issue by surveying substantially larger sample sizes have suffered from extreme beam dilution, due to the very small angular size of typical chemically rich hot cores. Here, we propose to exploit both the sensitivity and spatial resolution of ALMA to conduct a distance-limited survey of twenty five hot core sources. We target several spectral windows designed to provide the maximal scientific return, and will use the results to calibrate several of the industry-standard models and identify critical areas in which these models need refinement. | High-mass star formation, Astrochemistry | ISM and star formation | 2022-09-03T21:44:42.000 |
| 1535 | 2013.1.00535.S | 21 | Probing the AGN activity and molecular interstellar medium in ultra-luminous infrared galaxies using CH | The goal of this proposal is to establish the CH/CO line ratio as a discriminator between AGN and star-formation dominated galaxies by observing CH (at 560 microns) and CO (J=1-0) in five ultra-luminous infrared galaxies, with and without AGN, at z ~ 0.1. In a small sample of local galaxies observed with the Herschel Space Observatory, we found that the CH/CO abundance ratio is almost an order of magnitude higher in an AGN-dominated galaxy (NGC 1068) compared to three starburst -dominated galaxies (Arp 220, M 82 and NGC 253). This is consistent with the higher abundance of CH expected in X-ray dominated regions, fueled by the presence of the AGN. In addition, estimation of the molecular hydrogen column densities from CH and CO will enable us to test whether the CH is coming from diffuse or dense gas, and thus its reliability as a mass tracer. With the end of the Herschel mission, observations of far-infared CH lines are impossible in nearby galaxies because of atmospheric water vapor. Band-8 of ALMA can detect these lines for galaxies at z > 0.08, the lowest possible redshift for which such a study can be performed. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2016-08-10T14:36:04.000 |
| 1536 | 2016.1.01425.S | 18 | Resolved Imaging of Radio Photospheres | We propose to obtain spatially resolved 1.3-mm imaging observations of the radio photospheres of a sample of four asymptotic giant branch (AGB) stars. Radio photospheres lie just inside the dust formation zone of these mass-losing stars, hence their study probes the region of the stellar atmosphere where the stellar wind is launched. Our previous imaging observations of radio photospheres with the VLA and ALMA show that their shapes are generally non-spherical, and there is now evidence that these shapes change on timescales of several months or more. New observations with ALMA will provide confirmation that the apparent shapes are not instrumental artifacts and will permit us to distinguish between possible origins for these shapes. The ALMA data will also probe deeper into the stellar atmosphere than shorter wavelength VLA observations, providing a measure of the change in temperature with radius. Finally, the ALMA data will uniquely permit detection and characterization of spots, convective cells, or other brightness non-uniformities across the radio surfaces of the stars. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-10-10T09:03:06.000 |
| 1537 | 2013.1.00955.S | 60 | Properties and evolution of embedded protostellar disks | ALMA is already providing exciting results on how circumstellar disks form around low-mass young stars and how they evolve from the embedded through planet-forming stages. In this proposal we will attack the question: What is the relation between the formation and early evolution of circumstellar disks and the physics of the inner regions of collapsing protostellar envelopes? We will utilize ALMA's Band-7 to image a representative sample of 12 embedded protostars from the Ophiuchus star forming region in molecular lines from a selected set of isotopologues of common molecular species probing material with high temperatures and densities in the inner envelopes and circumstellar disks. This study will begin the process of assembling the key statistics required to understand the formation and early evolution of circumstellar disks, as well as provide key insight into the physics and timing of protostellar accretion. | Low-mass star formation | ISM and star formation | 2016-08-25T12:33:45.000 |
| 1538 | 2013.1.00205.S | 8 | Smoking gun confimation of dusty nuggets as progenitors of the red nuggets at z~2 | The discovery of the "red nugget" population (massive, compact, quiescent galaxies) at z=2 indicates that early passive galaxies were remarkably compact compared to their present-day elliptical counterparts. Recent observations have identified a population of compact, star forming galaxies (so-called "dusty nuggets") that appear to be the direct progenitors of the red nugget galaxies. While several pieces of indirect evidence link these two populations, ALMA observations will provide the smoking gun confirmation that dusty nugget galaxies are the star forming progenitors of the first generation of red sequence galaxies. Therefore, we request 3.7 hours on-source to obtain Band-7 luminosities and continuum maps on eight dusty nuggets to: (a) determine if their star-forming components are as compact as the stellar components of red nuggets, and (b) verify a short quenching (gas depletion) timescales consistent with the rapid build up the red nugget population. | Galaxy structure & evolution | Galaxy evolution | 2016-11-17T23:21:09.000 |
| 1539 | 2021.2.00075.S | 6 | Measuring the background temperature of Orion Nebula Cluster disks | We propose to mosaic the central 2.7' x 2.7' region of the Orion Nebula Cluster (ONC) with the ACA and TP array. These observations will probe extended molecular cloud structures in the region, which can influence the morphology of gaseous circumstellar disks observed with ALMA. In young, massive clusters like the ONC, we expect significant extended emission. We will target the CO(3-2) and HCO+(4-3) lines with a sensitivity of 0.2 K and spectral resolution of 0.25 km/s. These lines have been utilized in recent ALMA surveys of the ONC, which detected several-dozen gas disks not only in emission but also in absorption against the bright background cloud. Our short-baseline observations will complement the ALMA surveys and yield precise measurements of the cloud intensity towards known disks and proplyds in the region. With these measurements, we can extract cloud-corrected measurements of disk CO(3-2) and HCO+(4-3) emission for all of the disks detected in absorption with ALMA. By comparing the underlying physical/chemical properties of disks seen in emission vs. absorption, we will constrain the impact of the stellar cluster environment on circumstellar disk evolution. | Disks around low-mass stars | Disks and planet formation | 2024-05-11T18:29:55.000 |
| 1540 | 2018.1.01405.T | 78 | Revealing the Structure and Magnetization of GRB Jets with ALMA Polarization Observations | Polarization measurements of the luminous afterglows of long-duration gamma-ray bursts (GRBs) have long been predicted to probe the structure and magnetization of their relativistic jets, revealing the nature of their elusive central engine. While polarization of the reverse shock (RS) probes ordered magnetic fields in the outflow, polarized forward shock (FS) emission is sensitive to the jet angular structure and viewing geometry. ALMA Band 3 provides an ideal window to search for these polarization signatures, as the emission from the shocks is observable longer in this band than at higher frequencies, while being unaffected by interstellar scintillation and depolarization from self-absorption relative to lower frequencies. We propose a pilot ALMA full linear continuum polarization observation of a bright GRB afterglow in Band 3 to capture the radio polarization signature of GRB jets for the first time, aiming to constrain the magnetization, angular structure, and viewing geometry, and placing unique constraints on the central engine and jet acceleration mechanisms in these relativistic transients. | Transients | Stars and stellar evolution | 2020-11-30T15:20:30.000 |
| 1541 | 2021.1.00310.S | 3 | Constraining dust growth in a strongly turbulent disk from polarization observations | We propose to observe the polarization from the transitional disk around DM Tau to constrain dust fragmentation and planet formation. This object is the only source for which strong gas turbulence has been detected from line broadening of molecular line emission. The strong gas turbulence causes dust fragmentation, making it difficult to form planets. Therefore, we propose to determine the dust size from polarization observations in Band 7. Dust polarization observations provide a robust method for estimating the dust size, and we can determine the dust size whether the disk is optically thick or thin. If polarization is not detected, we can place strong limits on the dust size. This is a proposal for the first polarization observations of a disk with strong turbulence, and it will reveal the effects of gas turbulence on dust growth. We also propose to observe C17O line emission simultaneously with the polarization observations to trace the radial profile of the gas surface density. We can produce a moment 0 map without losing continuum sensitivity with our observational setting. | Disks around low-mass stars | Disks and planet formation | 2024-01-30T07:36:54.000 |
| 1542 | 2023.1.00299.S | 6 | Resolved Multi-J CO/[CI] study of a strongly lensed, Planck-selected z = 2.66 dusty protocluster of at least 9 DSFGs | We propose, for the first time in a gas-rich z>1 overdensity, a multi-line modeling of the [CI] / CO line and dust spectral energy distributions (SED). PJ0846 is an all-sky Planck selected protocluster consisting of 9 strongly lensed dusty star-forming galaxies (DSFGs) within 100 kpc at z=2.66. This analysis aims to determine the mechanisms driving SF in dense environments and search for evidence of quenching prior to halo mass assembly. Piecemeal archival data with limited sensitivity has sparked dedicated follow-up (0.1-0.2") observations of [CI], CO (3-2, 7-6) emission lines and ACA B9 continuum measurements to constrain the rise/fall of the CO ladder and the peak of the dust SED. What sets this project apart is: (1) PJ0846 is a lensed protocluster field with 9 DSFGs allowing high S/N multi-line and continuum studies, while removing an important systematic uncertainty in gas mass via modeling, and (2) an existing lens model will use the data to probe spatially resolved gas excitation conditions at 10 to 100 pc scales to examine intrinsic gas properties associated with this overdense burst of DSFGs within a protocluster environment at Cosmic Noon -- all within a single field. | Starburst galaxies | Active galaxies | 2024-12-27T17:23:10.000 |
| 1543 | 2019.1.01282.S | 16 | Constraining the sulphur chemistry through observations, lab experiments, and models | Sulphur is one of the most abundant elements of the interstellar medium, and it is also one of the elements where the chemistry is the least understood. This means that although we can readily observe S-bearing molecules in practically every type of environment, we do not know enough that we can use the chemistry to inform us about the physical conditions. To remedy this, we here propose to observe eight different S-bearing molecules toward a shock position in BHR71, a source where atomic S is bright and where we have a chance to obtain a complete inventory of sulphur compounds. A shock position is in many ways the ideal laboratory to study the sulphur-chemistry, because species otherwise locked up on grain surfaces are liberated and observable in the gas phase. To understand the observations, we are carrying out state-of-the-art laboratory experiments. The results of these experiments are incorporated into sophisticated shock models. This unique approach puts us in an ideal position to finally start understanding the sulphur-chemistry in the ISM. | Outflows, jets and ionized winds, Astrochemistry | ISM and star formation | 2021-03-25T04:53:33.000 |
| 1544 | 2012.1.00479.S | 11 | Imaging the molecular torus of the active galactic nucleus in the Circinus galaxy | A toroidal distribution of molecular gas and dust is a key component in our current picture of active galactic nuclei (AGN). This so-called "molecular torus" is held responsible for the orientation dependent obscuration of the central engine, and it plays a fundamental role for the accretion onto the supermassive black hole. Despite its importance for our understanding of AGN, its physical properties remain unclear and its existence is still disputed. Using the unprecedented imaging capabilities at high angular resolution of ALMA, we propose to map the molecular material of the outer torus in the Circinus galaxy, the nearest Seyfert 2 galaxy. The observations of CO(3-2) and CO(6-5) in this showcase study will, for the first time, provide a model-free image and direct information on the geometry, morphology, kinematics and accretion flow of the molecular material on parsec scales in an AGN -- something which has not been possible since the torus paradigm was established 25 years ago. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-09-23T02:29:13.000 |
| 1545 | 2023.A.00022.V | 0 | Exploration of High-Frequency SiO Masers with VLBI | Newly available ALMA spectral line VLBI capabilities are poised to enable for the first time studies of the dynamic atmospheres of evolved stars at sub-mas resolution using high-frequency (>200 GHz) masers. However, a roadblock to planning such studies is a lack of basic knowledge of the properties of high-frequency masers on VLBI scales. To address this, the Event Horizon Telescope has approved exploratory observations of the 28SiO v=1, J=5-4 masers in a sample of 5 evolved stars in April 2024 that will be the first to probe high-frequency masers at <1 mas resolution. Here we propose to allow phased ALMA to join these observations in order to dramatically improve the ability to detect and characterize the masers on global baselines. Outcomes will include constraints on their brightness temperature and polarization properties on sub-mas scales. The current observations are proposed as a DDT program because of their exploratory and potentially high-risk nature. We aim at expedited publication to inform the design of future ALMA proposals focused on VLBI imaging of high-frequency masers, including those aimed at studies of evolved star atmospheres on scales down to ~0.002R_star. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 3000-01-01T00:00:00.000 |
| 1546 | 2021.1.00739.S | 32 | Propagation of cosmic rays in molecular clouds interacting with a supernova remnant | Cosmic rays (CRs) are a major component of the Galaxy. Especially, since low-energy CRs lose their energy via ionization, they are believed to have a strong influence on the chemical evolution in molecular clouds and on star and planet formation. However, the influence of CRs has been discussed only hypothetically in theories because the propagation process of CRs in molecular clouds is highly unknown. A recent study noted that CR protons with E~0.01 MeV, ~10 MeV, ~GeV attribute to the ionization rate, Fe I Ka line, and Gamma-ray emission, and indicated that the relative spatial distributions among the the three observables are the key to reveal the propagation process. Actually, there are no samples where the three observables were measured in the same region. We focus on the southwestern edge of the supernova remnant W44, where both the Fe I Ka line and gamma-rays are detected. We propose DCO+ (J=2-1) and H13CO (J=1-0) observations at two positions in this region to measure the ionization rate and its spatial distribution. This observation will reveal the propagation of MeV CRs observationally for the first time. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-04-13T18:37:02.000 |
| 1547 | 2022.1.01365.S | 48 | Investigating possible protoplanetary disk instabilities induced by late infall | While Class II protoplanetary disks have typically been thought of as isolated, scattered light and molecular line images are increasingly uncovering ``late infall'' signatures in the form of large-scale arm or tail-like structures connected to the disks. Simulations suggest that infalling material can give rise to disk instabilities, resulting in substructures such as spiral arms, vortices, and misalignments. These substructures, in turn, can influence the formation location and orbital properties of protoplanets. To investigate this potential link between infall and disk structural evolution, we propose high resolution continuum imaging and sensitive CO mapping of four Class II disks that exhibit evidence for disk perturbation by late infall. We will characterize the substructure morphology and examine their spatial association with larger-scale structures and possible variations with infalling mass. These detailed images will advance our understanding of the variety of circumstances under which planet formation takes place. | Disks around low-mass stars | Disks and planet formation | 2024-07-18T21:21:05.000 |
| 1548 | 2018.1.00771.S | 119 | Born with siblings: will I ever get my own space? | A large fraction, if not the majority of stars form in multiple systems, yet the impact of the presence of close-by stars is usually neglected when studying how protoplanetary disks evolve and how planets form in them. One of the main reasons is the relative lack of extensive studies at high angular resolution of the properties of protoplanetary disks in multiple stellar systems. Our Cycle 4 survey of disks in the Taurus star-forming region at 0.1" resolution shows that mm-dust disk radii in 11 binary systems are among the smallest in the sample, and are as small as ~0.05-0.1 times the projected separation of the binary stars. These values are explainable by a tidal truncation event, but only if the eccentricity of the orbits is larger than 0.8. Very eccentric orbits would strongly impact the possibility of forming planets in these disks, as their radii would be just a few au. We propose here to obtain the still missing observation of CO in these disks around multiple stars in the Taurus region. We will determine the gas disk radii to confirm whether these disk are really small. Such a result would strongly impact our current understanding of planet formation around binaries. | Disks around low-mass stars | Disks and planet formation | 2020-12-31T20:45:02.000 |
| 1549 | 2023.1.01182.S | 0 | Unveiling the physics controlling cloud and star formation in extragalactic Central Molecular Zones (eCMZs) | Gas-rich galaxy centers like our own Central Molecular Zone (CMZ) are extreme environments for cloud and star formation where many formation promoting or inhibiting forces acting locally or on larger scales compete. We propose ~20pc resolution, sensitive (rms~0.5K per 2.5 km/s) CO(2-1) imaging of a representative, unbiased set of 15 nearby well-studied extragalactic CMZs to provide the first robust statistical assessment of CMZ molecular cloud (complex) properties (mass, line width, size, pressure, timescales etc.) and correlate these with global CMZ and galaxy properties to determine whether local processes (i.e. stellar feedback) or large-scale environment control their star formation activity and answer if the unexpected properties of our own CMZ are unusual or common. Further we will quantify if and how central AGN and starbursts alter CMZ cloud properties, and thus regulate subsequent star formation. This comprehensive study will provide the urgently needed data to distinguish between theories for CMZ star formation that either argue for a highly time-variable evolution caused by local processes or a more steady-state evolution regulated by the large-scale environment. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2025-07-01T23:22:30.000 |
| 1550 | 2021.1.00473.S | 95 | A Chemistry Survey of Protoplanetary Disks in Binary Systems | T Tauri disks display diverse chemical inventories. The reason for this diversity is unknown. In particular it is currently unclear what role, if any, initial chemical conditions play in setting the disk chemical trajectories. To address this, we propose to map out the chemistry of five pairs of nearby intermediate-separation binary T Tauri disks at 0.3" scale. Each binary system likely formed from a single cloud core with identical chemical initial conditions. By comparing chemical inventories within binaries and between binary pairs we will obtain first constraints on how important these initial conditions are. More particularly we will probe the disks using common tracers of disk CO masses, probes of C/N/O gas-phase ratios, and deuterium fractionation probes, and in a number of organic molecules of different complexity. Together these observations will enable unique constraints on whether disk chemistry mainly depends on the chemical starting point, or whether the chemistry is completely reset and only depends on the details of star+disk system. Which scenario correctly describes reality will have a large impact on how we model the chemical evolution in planet forming disks. | Disks around low-mass stars | Disks and planet formation | 2023-07-13T14:01:32.000 |
| 1551 | 2022.1.00534.S | 20 | Caught red handed: dusty quasars blowing out molecular gas | The canonical picture of galaxy evolution invokes the injection of energy from supermassive black holes to reduce star formation efficiency in massive galaxies. However, the physical channels that allow energy and momentum released on sub-pc scales to affect gas on galactic scales are largely unconstrained. Theoretical models predict that radiation pressure on dust in the vicinity of the black hole is a major driving mechanism of galactic-scale outflows of cold gas. A recent study has found evidence for a direct link between quasar dust-reddening and molecular outflows. Here, we propose a survey of 10 reddened quasars at z=2.5 in CO(9-8) or CO(10-9) to investigate this relationship and explore the impact of radiative feedback on star-forming gas. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-05-05T19:44:37.000 |
| 1552 | 2018.1.00299.S | 470 | Infall in the very early stages of high-mass star formation | Although high-mass stars are the main source of kinematic and chemical enrichemnt in galaxies, their formation, in particular how they accrete their initial mass, is still poorly understood. To understand this, we need to measure the properties of high-mass star forming cores in very early stages of evolution. With this aim we performed an ALMA survey of high-mass clumps (500 - 5000 Msun) in early stage of evolution, identifying a large sample of massive pre-stellar core candidates. For one of the clumps, G331, addditional ALMA observations shows infall signatures to its most massive core, suggesting that is still accreting material. Our results suggest that the initial condition of high-mass stars are sub-virial cores of intermediate mass accreting from their environment. To determine if the process seen for G331 is ubiqutous, we propose to observe a combination of optically thick (HCO+, HNC) and thin (N2H+) tracers to meassure the total mass accretion (radial and/or along filaments) onto the 12 most massive cores detected in our survey. With these observation we will determine how high-mass stars acquire their mass and put constraints on high-mass star forming models. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-09-03T17:43:16.000 |
| 1553 | 2012.1.00536.S | 0 | Physical Properties of Galaxies that Ionize the Universe | Measuring the properties of low-luminosity galaxies near redshift 6 is central to understanding the reionization of the universe. Although hundreds of bright galaxies have now been identified at this era, their number density is too low to even maintain the ionization of the intergalactic gas, and lower luminosity galaxies detectable only via their line emission provide the closest relation between any high-redshift galaxy population and the sources that actually reionized the universe. Prior to ALMA, however, our knowledge of these important galaxies was limited to number counts and luminosity functions of hydrogen Lyman-alpha emission. The luminosity and line profile of this resonance line depend sensitively on the gas kinematics and dust content of the host galaxy, so Lyman-alpha observations alone provide little physical information about the galaxy properties. To establish the typical star formation rate, dynamical mass, and systemic velocity for the lowest luminosity galaxies yet detected at this important era, we request ALMA observations of their [CII] 158 um fine structure emission. | Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies | Galaxy evolution | 2015-07-02T13:41:03.000 |
| 1554 | 2016.1.00985.S | 19 | Dense Core Magnetic Fields in High-Mass Infrared Dark Clouds | High-mass Stars are cosmic engines known to dominate the energetics in galaxies. However, their formation is still not well understood. Massive, cold, dense clouds, often appearing as Infrared Dark Clouds (IRDCs), are massive stellar nurseries. No measurements of magnetic fields in IRDCs in a state prior to the onset of high-mass star formation (HMSF) have been available until very recently. Only studies of early stages can constrain the initial conditions for HMSF. We now reported observations of magnetic fields in two of the most massive IRDCs. We show that G11.11-0.12 and G0.253+0.016 are strongly magnetized. This shows that magnetic field is as important as turbulence and gravity for HMSF. We now propose to study the field on sub-parsec scales where the gas fragments into cores that form stars. To do so we pick dense cores within these unique unperturbed IRDCs. The interpretation of observations is supported by extensive custom--made numerical simulations of magnetized clouds. Combined with near-IR, far-IR and submm polarization data on larger scales, these observations will provide the first panoramic view of the magnetized nature and thus initial conditions of HMSF. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-07-27T14:47:05.000 |
| 1555 | 2021.1.00726.S | 16 | Constraining the Interstellar Medium Properties of the Most Luminous Galaxy Known | At a redshift of 4.601 and with a luminosity of Lbol = 3.5 x 10^14 Lsun, the obscured quasar WISE J22460526 (W2246) is the most luminous galaxy detected to date. ALMA observations of the [CII]158um emission line have revealed a uniform, highly turbulent interstellar medium (ISM) that is being blown away from the host galaxy isotropically, likely due to the energetic feedback from central AGN. Deep observations of the 212um dust continuum further revealed that the gas reservoir at the center of W2246 is being fed by a multiple merger process, while [NII] observations point to an extremely dense ionized medium. However, there are many ISM properties of this outstanding source that are still unknown. Here we propose to obtain ALMA observations of the [OIII]88um emission line in W2246 at an angular resolution similar to that of the existing line dataset, ~0.3". When combined with the wealth of far-IR emission lines already in the ALMA archive, these observations will allow us to fully characterize the properties of the gas in a galaxy that represents the ultimate laboratory for studying and model the ISM physics and kinematics under strong feedback at high redshift. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2023-12-20T17:27:06.000 |
| 1556 | 2022.1.01786.S | 51 | The heating mechanism for the cool, far-IR emitting dust in AGN | In order to understand the links between AGN and galaxy evolution, it it important to determine precise star formation rates (SFR) for the AGN host galaxies. Far-IR luminosities are often considered to provide a "clean" diagnostic of the SFR. However, recent work has suggested that emission from the kpc-scale NLR or outer parts of the circum-nuclear torus can make a major contribution, and perhaps dominate, the far-IR continuum. Therefore, we propose to use the unique capabilities of the ACA to make a decisive test of the idea that AGN-heated cool dust is important at far-IR wavelengths by using Band 9 (680GHz) observations to image three nearby radio AGN. If the far-IR emission proves to be emitted by extended cone-like structures aligned along the axes of the large-scale radio structures (i.e. following the morphology of the NLR) this will provide clear evidence for a major contribution of the NLR at far-IR wavelength. On the other hand, in the case of a dominant torus component, the far-IR emission will be concentrated in a nuclear point source. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-09-08T21:44:39.000 |
| 1557 | 2023.1.00533.S | 0 | Suppressed Star Formation Near Sgr A*? | We propose 1 mm polarization mosaic observations of the circumnuclear disk (CND) to investigate the role of the magnetic (B-) field on the nuclear star formation near Sgr A*. Recent ALMA CS line data reported that a lower limit of 62 out of 1091 cores are dense enough to resist the tidal disruption. The B-field appears to be dynamically important to regulate the gas in the CND, which can potentially increase gas density higher than the tidal threshold. Despite this, no evidence of star formation is seen in the CND. The unexplored mechanism that may be suppressing star formation in this environment is support against gravitational collapse via the strong B-field. We propose to resolve the CND down to the protostellar core scale to constrain the small-scale B-field geometry in the CND. We aim to (1) resolve the B-field orientation towards the cores to investigate whether the B-field tension force is sufficient to suppress star formation, and (2) to use the optically thin 1 mm dust continuum emission to resolve the embedded core populations down to 0.1 Msun. These observations will provide unparalleled insight into the physics of star formation in the vicinity of a SMBH. | Galactic centres/nuclei | Active galaxies | 3000-01-01T00:00:00.000 |
| 1558 | 2019.1.00021.S | 36 | The structure of the detached shells around DR Ser, V644 Sco, and S Sct | In Cycle 6 we proposed to observe the detached shells around the carbon AGB stars DR Ser, V644 Sco, and S Sct in CO(1-0) to determine the evolution of the mass loss from AGB stars during and after a thermal pulse. To recover the flux on all scales, the Cycle 6 observations required two main-array configurations. The extended configuration at 1" resolution was observed in Cycle 6. We here request to observe the remaining configurations to create a complete dataset that is essential to correctly determine the creation and evolution of the detached shells. The shells span the entire age range of known detached shell sources, allowing us to constrain the mass-loss rate shortly after the thermal pulse, and to follow the evolution of the shells until they get photodissociated. Un unexpected velocity-splitting of the shells in the Cycle 6 data further confirm that the data will constrain the hydrodynamical properties of the shells. The proposed observations will yield the most detailed view of the evolution of the mass loss throughout the TP cycle on the AGB, and will constrain critical aspects of late stellar evolution, and hence of the chemical evolution of stars and the ISM. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2021-04-07T19:31:44.000 |
| 1559 | 2016.1.00790.S | 144 | Constraining Quenching Processes in Galaxies Significantly Below the Main Sequence at z~0.7 | Large surveys have shown that most galaxies fall along a well-defined relationship between star formation rate (SFR) and stellar mass. An increasing fraction of low-redshift massive galaxies have markedly depressed SFRs, but the physics of this "quenching" are poorly understood. Proposed quenching mechanisms imply very different, testable predictions for the molecular gas properties. If the decrease in SFR is due to bulge formation, massive galaxies can have high gas masses but long depletion times, but if quenching is due to gas depletion, we expect low gas fractions and short depletion times. We propose to measure molecular gas masses in a sample of massive z~0.7 galaxies with SFRs 3-10x below the main sequence. These objects are selected from the LEGA-C survey of galaxies with ultra-deep VLT spectroscopy, and span a range of colors, dynamics and stellar ages. We will extend gas scaling relations to the quiescent population at z~0.7, when the red sequence is actively being assembled. Our results will provide valuable constraints on theoretical quenching prescriptions, and reveal whether tension observed in the local quiescent population improves or worsens at moderate redshift. | Galaxy structure & evolution | Galaxy evolution | 2018-03-21T17:16:20.000 |
| 1560 | 2012.1.01011.S | 8 | Nature of the pre-brown dwarf core Oph B-11 | The origin of brown dwarfs (BDs) is an important astrophysical mystery because its solution can also shed light on how a broad range of objects, from typical stars to giant planets, are formed and gain their masses. Using the IRAM Plateau de Bure interferometer (PdBI) at 93 GHz, we have recently identified the first bona-fide example of a pre-brown dwarf core, a self-gravitating starless condensation of gas and dust in the brown-dwarf mass regime (André, Ward-Thompson, Greaves 2012, Science, 337, 69). Given the current uncertainty in its radius (< 460 AU) and mass (~20 MJup), this object (Oph B-11) may even turn out to be the precursor to an isolated planetary mass object. Our result tends to support models according to which BDs form in a similar manner to normal stars, from the direct collapse of a prestellar core. We propose ALMA Cycle 1 observations in Band 3 (93 GHz), Band 6 (220 GHz), Band 7 (370 GHz), and Band 9 (670 GHz), in order to obtain robust measurements of the size, structure, mass of Oph B-11, and constrain its levels of rotation, infall, outflow motions. Such measurements may serve as benchmarks in future surveys for pre-brown dwarfs in nearby clouds, which will be necessary to assess whether most BDs originate from ultra-low-mass cores such as Oph B-11. | Low-mass star formation | ISM and star formation | 2015-05-19T13:39:14.000 |
| 1561 | 2019.A.00006.T | 39 | Diagnosing the Heart of an Old Supernova | Recent observations emphasize the need to invoke a central engine in a growing number of supernovae to be able to explain the energetics. The most common model for this engine is in the form of a rapidly spinning pulsar remnant that imparts its energy to the supernova ejecta as it spins down. This pulsar should produce pulsar wind nebula (PWN) emission from its strong ionized wind. Although the supernova ejecta should initially be optically thick to this emission, it is expected to become visible in the years to decades after explosion. Here, we propose 84 minutes of ALMA observations at Band 3 and Band 7 to investigate a supernova that shows strong indications of an emerging PWN emission. If this is the case, then this will be the first time that we can actively monitor a pulsar and its pulsar wind nebula from the time of formation. | Supernovae (SN) ejecta | Stars and stellar evolution | 2020-08-19T19:03:19.000 |
| 1562 | 2015.1.00242.S | 570 | BASIC: A Bright ALMA Survey of SMGs in the Chandra Deep Field-South | We propose an ALMA survey of a large, uniformly selected sample of 76 bright SMGs (~1 source per 1.5 arcmin^2) discovered with SCUBA-2 down to the confusion limit of S(850um)>2 mJy in the GOODS-S/CDF-S. These observations will bridge for the first time the critical transition range in SFR (~500 M_sun/yr) between the rare hyperluminous, dusty, optically faint galaxies found in shallow, wide-area submm surveys (e.g., LABOCA, HATLAS, SPT, Planck) and the extinction-corrected UV-selected Lyman Break Galaxies that are being probed with direct ALMA observations of small areas. These two populations are essentially disjoint, and key physical changes in star formation mechanisms may be occurring over this SFR range. ALMA observations of our SCUBA-2 sample will allow us to determine what fraction are single or multiple sources, measure their physical sizes and morphologies, pinpoint optical, NIR, and X-ray counterparts, construct spectral energy distributions, and estimate SFRs for these unique sources. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-01-10T00:00:00.000 |
| 1563 | 2015.1.00551.S | 44 | Mechanism of Material Feeding to the Planet-Forming Disk in HL Tau | We propose ALMA observations of HL Tau in the C18O (2-1), 13CO (2-1), and SO (6_5-5_4) lines at Band 6, and the HCN (1-0), HCO+ (1-0), and the SO (3_2-2_1; 4_5-4_4) lines at Band 3. The ALMA discovery of ringlike gaps in the circumstellar disk around HL Tau implies the ongoing planet formation. Our recent work using the ALMA long baseline data identified both the inner (r~100 AU) disk in Keplerian rotation and the outer envelope in the infalling motion. The infalling velocity appears to be slower than the free-fall velocity, though the missing short-spacing information and contamination from the associated outflows hinder us from unveiling the gas motion unambiguously. Here we propose to perform ALMA observations to sample the shorter spatial scales and combine the data with the long-baseline data, to unveil the mechanism of material feeding from the envelope to the planet-forming disk. We will also observe the optically-thin C18O line to avoid the outflow contamination, and multi-transitional SO lines to study the physical conditions of the accretion shocks at the transitional region from the envelope to the disk. | Low-mass star formation | ISM and star formation | 2020-10-20T00:00:00.000 |
| 1564 | 2018.1.00799.S | 98 | What is the role of angular momentum in disk formation? Comparing big and small disks around Class 0 | The existence of large and massive disks around Class 0 protostars is hotly contended, both observationally and on theoretical grounds. One of the key parameters to constrain the disk formation is the radial distribution of the specific angular momentum, which is directly related to the maximum size of a Keplerian disk. We propose to observe 2 Class 0 objects with very different disk properties with ALMA in Band 3 to determine the dense gas kinematics. These observations will provide a unique dataset to determine the angular momentum profile form 10,000 au down to ~500 au for both sources. These results will establish if the difference in the disk size between these two sources is due to the initial conditions of the parental dense core. | Low-mass star formation | ISM and star formation | 2020-02-19T22:24:20.000 |
| 1565 | 2011.0.00017.S | 0 | Expanding the frontiers of chemical complexity with ALMA | The search for complex pre-biotic and biotic molecules in the interstellar medium (ISM) will be a primary focus of ALMA science. The molecular inventory of meteorites found on Earth includes more than 80 distinct amino acids (the building blocks of proteins), and their composition suggests an interstellar origin. The key search site for new complex organics in the ISM is the hot dense core Sgr B2(N), due partly to its high column density. However, the firm identification of new molecules requires a robust spectral model to unweave the emission lines of weakly-emitting, more complex, species from known molecules. We have already constructed a unique model of this kind, using our previous single-dish line survey, which has already allowed our team to uncover several new species. We propose to use ALMA Early Science to perform a deep, unbiased line survey of Sgr B2(N) in band 3 (8 hours observing time). The proposed survey will improve the detection threshold for complex organic molecules by nearly a factor of 20 compared to our previous survey of this source. Such a sensitivity improvement should lead to the firm detection of a few, perhaps a dozen, new complex organics, while the adaptation of our existing spectral model will allow a rapid turn-around from detection to publication. The use of our team's cutting edge chemical models will allow the broader implications of new discoveries to be understood, and place strong constraints on chemical formation pathways. The discovery of biologically-relevant molecules in the ISM will be of high scientific impact, and is of broad appeal to the public and the media. The combination of ALMA's unique spectral sensitivity with our established methodologies will provide an efficient showcase of ALMA's capabilities in this field. | Inter-Stellar Medium (ISM)/Molecular clouds, Astrochemistry | ISM and star formation | 2014-09-12T00:00:00.000 |
| 1566 | 2012.1.00524.S | 6 | Shaping the Outflows of Binary AGB Stars | The required conditions for stars to evolve into planetary nebulae (PNs) continue to puzzle. Since PNs are found in a wide variety of shapes, processes that could sculpt circumstellar envelopes (CSEs) are being investigated. A binary companion will have a strong gravitational effect, but known binary AGB stars are rare. We propose to observe a small sample of confirmed binary AGB stars, covering a decisive range in binary separation, in order to determine the gravitational influence of a companion on the circumstellar morphology of the AGB primary. ALMA is the only facility with the necessary sensitivity and resolution to study the effects of binary interaction systematically. The data will be analysed using state-of-the-art 3D radiative transfer and the results will be compared to 3D Smoothed Particle Hydrodynamics (SPH) models of the gravitational interaction. By constraining the shaping effects we believe that long-standing questions regarding this important transitional phase can be answered, and that major advances in the study of late stellar evolution will be made. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-06-05T16:49:11.000 |
| 1567 | 2022.1.01771.S | 30 | Resolving the feedback action of cosmic rays in distant star-forming galaxies | The exact role cosmic rays (CRs) play in mediating feedback within galaxies is a pressing question. We propose high resolution ALMA Band 7 observations of redshifted OH+, H2O+ and CH+ absorption lines from a galaxies at z~2.2, which has previously been found to exhibit an inside-out radial quenching pattern in its star-formation. This will reveal the interaction patterns of CRs within their host galaxy on 0.5 kpc scales. Accompanied by existing H-band VLT observations to trace the star-formation within this galaxy, the requested data will demonstrate the impact of CR quenching in shaping the evolution of this system, and will capture the importance of CRs in bringing about the downfall of star-formation in galaxies during the cosmic noon. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2024-09-14T12:32:52.000 |
| 1568 | 2017.1.00568.S | 27 | Water masers toward IRAS16293-2422 | Water masers offer the possibility to diagnose gas motions in the disk and outflow of deeply embedded protostars at incredibly high angular precision, even by ALMA standards. Traditionally the 22 GHz transition was used for observing masers, and the observations reveal how dense and hot gas (n~1e8 cm-3, T~1000K) moves over timescales of years in both jet/outflow shocks as well as the disk surface on <10AU scales. ALMA is now opening the window to observing the 183 GHz H2O transition, a significantly lower-excited maser than that at 22 GHz (n~1e6 cm-3, T~150K). These lower pumping conditions imply that the maser is more readily excited in protostellar systems, where such physical conditions are much more prevalent than those required to pump the 22 GHz maser. We therefore propose to undertake a pilot study of the 183 GHz maser toward the prototypical deeply embedded source, IRAS16293-2422, along with its H2-18O equivalent at 203 GHz. These observations will open up a new window for ALMA to track gas dynamics on the smallest scales. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-10-09T12:54:16.000 |
| 1569 | 2017.1.01358.S | 52 | C+ Emission from Luminous and Normal LAGER Lyman Alpha Galaxies at z=7 | We will observe the [CII] line for 6 Lyman-alpha emitters at z~7 from our LAGER survey. LAGER is the largest volume narrow-band survey at this redshift. The current sample is from a 1.2 million cubic-Mpc survey, which we aim to extend to 10 million cubic-Mpcs. After more than 12 nights of imaging and 3 of optical spectrosocopy we have a uniformly selected sample of 27 high confidence LAEs. We see an excess of highly luminous (L > 3 L*) LAEs. This parallels the change seen at the bright end of Lyman-break galaxies but is more dramatic. Do we have an excess of luminous LAEs because star-formation properties of galaxies have changed at cosmic dawn? or is it because the luminous galaxies form an ionized bubble in the local IGM, allowing Lyman-alpha to escape? [CII] observations will probe kinematics and dynamical masses, measure SFR independent of LyA, and measure velocity offsets between LyA and [CII] to test reionization. We will observe the [CII] line in three luminous and three "normal" Lyman-alpha emitters. This will double the number of galaxies at Z>6 where both LyA and [CII] have been observed, and will be the largest LyA selected sample at z=7. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2019-02-27T19:31:11.000 |
| 1570 | 2015.1.01107.S | 7 | Is precipitation driving radio mode AGN feedback in giant ellipticals? | The nature of the material accreted onto the supermassive black holes (SMBH) at the hearts of active galactic nuclei (AGN) with radio mode activity remains one of the outstanding questions of accretion physics. In particular, it is not clear whether the accretion in massive early type galaxies proceeds from the hot X-ray emitting interstellar medium (ISM) or from the accumulated cold ISM. Here we propose to map the CO line emission in NGC 4636, the nearest (d 14.7 Mpc) X-ray bright giant elliptical galaxy with a radio mode AGN and confirmed reservoirs of cold gas. This galaxy provides a unique opportunity to resolve the cold molecular gas on the smallest physical spatial scales in a radio mode AGN and map its distribution and the velocity structure down to the Bondi accretion radius of the central SMBH. In conjunction with existing multi-wavelength data, this pioneering observation will allow us to uniquely address the fundamental question: what is the nature of the material feeding radio-mode AGN? Is it cold or hot gas, or is the hot ISM undergoing a cooling instability before it is accreted onto black holes? | Early-type galaxies | Galaxy evolution | 2018-11-11T04:39:12.000 |
| 1571 | 2022.1.01215.S | 364 | Revealing Protocluster Growth Around Powerful Radio Galaxies Across Cosmic Noon | High redshift radio galaxies (HzRGs) are thought to pinpoint the cores of galaxy protoclusters. Yet, to date, there remains significant confusion about the Mpc-scale overdensities of obscured star formation around HzRGs. To remedy this situation, we reduced SCUBA-2 850micron data of 30 HzRGs at z=1-4.5, finding the central 6Mpc regions to be >5x overdense in submillimeter sources (SMGs) compared to the field. This depends critically, however, on spectroscopic confirmation and whether bright SMGs break into fainter sources at higher angular resolution. We propose ALMA Band-5/-6/-7 observations (FWHM~1-2") targeting CO(7-6) and [CI](2-1), and the continuum, in the 10 brightest SMGs in 10 HzRG fields (100 SMGs in total) across the Cosmic Noon (z=1.5-3.5). This will resolve the critical issues of redshift and source multiplicity, required to accurately quantify the SMG overdensities around HzRGs. It will provide unambiguous identifications in existing OIR data, allowing us to infer key physical properties of the SMGs. The outcome will be the first systematic study of SMG-overdensities and their evolution with redshift, and the physical properties of SMGs in overdense regions. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2024-01-11T12:16:07.000 |
| 1572 | 2011.0.00131.S | 0 | Piecing the shell together: ALMA and the detached shell around R Scl | Spherically symmetric and very thin shells of gas and dust have been observed around about a dozen of carbon AGB stars - evidence that these stars have undergone episodes of major mass-loss eruptions. The origin of these detached shells is likely connected to the changes in mass-loss rate and expansion velocity during a He-shell flash. Recurring He-shell flashes are responsible for the chemical evolution of the star, the circumstellar envelope, and eventually the interstellar medium. We propose to observe the detached shell around the carbon AGB star R Scl using the compact configuration of the ALMA early science array in the CO(1-0), CO(2-1), and CO(3-2) transitions in bands 3, 6, and 7, respectively. The images from the ALMA observations will give unique information on the structure and evolution of the gaseous detached shell, and allow to determine the change in the physical stellar parameters during a He-shell flash. The observations will hence shed light on the origin of highly episodic mass loss and the He-shell flash phenomenon, as well as the mass-loss mechanism on the AGB and the structure of the circumstellar medium. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2013-03-29T09:04:41.000 |
| 1573 | 2013.1.00163.S | 33 | Masses of Low Mass T Tauri Stars | We propose to measure the masses of young (<10 MY old) low-mass (<0.5 solar masses) stars by the rotation of their circumstellar disks. The improvements in the understanding of the evolution of young stars that result from the proposed research will enable astronomers to obtain a more reliable understanding of the mass spectra of the stars produced in star forming regions and of the chronology of their formation. | Disks around low-mass stars | Disks and planet formation | 2016-07-31T00:00:00.000 |
| 1574 | 2021.1.00222.S | 5 | The origin of Argonium (ArH+) | ABSTRACT: Among the many hydrides detected in the interstellar medium, the molecular ion ArH+ is uniquely expected to reach observable abundances only in nearly pure atomic hydrogen regions with less than 0.1% H2. Previous observations of ArH+ emission associated with the supernova remnant Cas A and ArH+ absorption along Galactic sightlines toward distant star-forming regions have allowed the identification of ArH+ and the evaluation of its column densities. However, due to the complexity of the velocity structure and the presence of large amounts of H2-bearing gas, information on the intrinsic ArH+ line profile and the in situ abundance of ArH+ cannot be extracted from the data. We propose to observe the ground state ArH+ transition at 617.5 GHz toward the radio loud quasar and bright ALMA calibrator 3C454.3 where there are exceptionally complete observations including optical NaI, KI, CaII absorption along with HI, OH HCO+, CO and many other molecules, tracing the cold and warm gas phases. The proposed observation will allow us to identify in a unique way the conditions under which ArH+ exists in the ISM and which phases of the atomic gas are traced by ArH+. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-07-29T20:42:51.000 |
| 1575 | 2018.1.00641.S | 3 | Evidence of accretion disks during the formation of high-mass stars in the Central Molecular Zone | The Central Molecular Zone (CMZ) in our Galatic Center is a unique high-mass star forming environment with extreme physical conditions. Whether accretion disks play a role in high-mass star formation in the CMZ in the same way as the Galactic disk regions is unclear. Our recent SMA, JVLA, and ALMA observations toward two massive clouds in the CMZ reveal four massive protostellar cores that may give birth to massive O-type stars, and tentative signatures of accretion disks are seen. To obtain critical evidence of accretion disks in these four cores, we propose to observe them with long baseline configurations to resolve them down to 300 AU. This will enable us to learn whether the formation of massive stars in the CMZ fits into the standard disk accretion model. | High-mass star formation | ISM and star formation | 2021-12-31T00:00:00.000 |
| 1576 | 2017.1.01002.S | 31 | Searching for hot molecular cores in the extreme outer Galaxy | The recent discovery of a hot molecular core in a nearby low metallicity galaxy, the Large Magellanic Cloud (LMC), suggests that the galactic metallicity has a significant effect on chemistry of warm and dense molecular gas associated with a protostar. While remarkable chemical differences are reported for the LMC hot core, it is still unclear if the observed chemical characteristics is essentially common in other low metallicity environments or it is unique only in the LMC. Here we propose ALMA observations to search for hot cores in the star-forming region at the edge of our Galaxy. The proposed target, WB89-789, is an active star-forming region located at the extreme outer Galaxy (galactocentric distance ~20 kpc), where the metallicity is lower than the solar neighborhood by a factor of four. The low metallicity environment of the outer Galaxy, which is common with the LMC, provide us an ideal laboratory to test the universality of the low metallicity molecular chemistry observed in the LMC. This proposal aims to elucidate a possible link between metallicity and hot core chemistry, particularly by focusing on properties of complex organic molecules and their parental species. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-09-21T16:02:49.000 |
| 1577 | 2019.2.00055.S | 9 | Tracing CO-dark molecular gas at low metallicity | We propose an ALMA/ACA 850 micron continuum map of most of the star-forming area of WLM, a Local Group dwarf irregular galaxy with an oxygen abundance that is 13% of solar. In C1 we detected 10 tiny CO cores in two star-forming regions in WLM, and in C6 we mapped WLM in CO(2-1). The unprecedented resolution (18 pc) of the continuum map proposed here in combination with our other data (Spitzer, HI, CO, Halpha, FUV) will reveal the distribution of the cool dust at the scale of FUV clumps. From these data, we will get a first glimpse of the distribution of total H2 gas, its relationship to the CO cores and to young stars, and the nature of CO-dark gas at a spatial resolution of 18 pc and at 13% solar metallicity. This will shed light on the physical conditions under which stars form in a metal-poor environment, possibly similar to that in the early universe. | Dwarf/metal-poor galaxies | Local Universe | 2022-10-19T19:25:24.000 |
| 1578 | 2015.1.01205.S | 26 | The early coevolution of galaxies and black holes | We propose observations of the dust continuum and of one high-J CO transition in six heavily obscured QSOs residing in SMGs at z>2.5 in the CDFS. All QSOs are obscured by an X-ray column density of NH>3e23 cm-2. Their hosts are massive (M*>1e11 Msun) and feature vigorous star formation rates (SFR>300 Msun/yr). Through band 4 observations with 0.3" FWHM resolution, i.e. half-light radius ~1 kpc at the median target redshift, we will measure the morphology and compactness of star formation and the mass and density of the ISM. With 5 hr of ALMA time (including overheads) we will assess whether: 1) star formation is taking place in a compact (~0.5-2 kpc) region, with size similar to that of compact quiescent galaxies (cQGs) at z<2. This, coupled to other physical quantities such as SFR, stellar mass, gas depletion time, would reveal whether our targets are the likely progenitors of cQGs; 2) the host gas density is so high that it can produce most of the nuclear absorption measured from the X-ray spectra. This might help explaining why the fraction of heavily obscured QSOs has been observed to increase with redshift. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2018-02-04T04:20:56.000 |
| 1579 | 2016.1.01591.S | 17 | Ice in the embers: Testing the existence of cold molecular gas in a lensed compact quiescent galaxy at z=2.15 | We propose for a CO(3-2) observation of a strongly lensed compact quiescent galaxy (cQG) where we find rotation and a compact exponential light profile, suggesting a disk galaxy. Otherwise, the proposed galaxy is a typical example of the population of compact cQGs, which have in the last couple of years been identified as an important piece in a consistent understanding of how galaxy evolves. The cQGs are widely believed to be dispersion-dominated bulges with an unknown quenching mechanism preventing further star formation, thus observing the molecular gas content will help unveil the true nature behind the cease in star formation. As the study of molecular emission from quiescent galaxies at z>2 is unprecedented, this can be considered a pilot study. Therefore, this observation is meant as a detection experiment and the observation time is chosen based on feasibility arguments and comparison to lower redshift post-starburst galaxies. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2018-05-18T04:06:40.000 |
| 1580 | 2017.1.01228.S | 15 | "Resolving" the Unusual Molecular Gas Excess in z=1.6 Cluster Galaxies | We propose for 4.4 hours of spatially-resolved (0.3) CO (2-1) emission in gas-rich z=1.6 cluster galaxies. Our Cycle 3 program of unresolved CO emission has uncovered massive gas reservoirs in 11 clusters galaxies, constituting the largest sample of molecular gas in z>1 clusters to date. These data reveal systematically higher gas fractions than the coeval field. The physical origin of this gas excess is not clear, and high-resolution imaging is crucial to investigate the nature of the CO in high-z clusters. Our proposed ALMA Cycle 5 observations will yield the first glimpse of spatially resolved molecular gas in high-redshift cluster galaxies, mapping out asymmetric CO morphologies and providing insight on how distant cluster environments affect the gas for the very first time. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2019-03-05T20:40:29.000 |
| 1581 | 2021.2.00102.S | 0 | Mapping the Large-Scale Flow of Material to a Protoplanetary Disk During Planet Formation | Protoplanetary disks have traditionally been viewed as isolated reservoirs of planetary building blocks. However, recent detections of large-scale streamers and spirals associated with Class II disks suggest that they can continue to accrete material from their surroundings while planet formation is underway. Observations of the RU Lup system have revealed both non-Keplerian spiral arms and a large, nearby arc-like structure, raising the possibility that the arc-like structure is feeding the disk. To investigate whether the arc-like structure is supplying new material to RU Lup and to estimate the available mass, we propose an ACA mosaic to map RU Lup's surroundings in CO isotopologue emission. These observations will advance our understanding of how late infall can affect the mass, composition, and angular momentum of disks, and therefore the properties of planets forming within them. | Disks around low-mass stars | Disks and planet formation | 2023-06-15T09:48:28.000 |
| 1582 | 2018.1.01055.L | 690 | The Chemistry of Planet Formation | Planets form and obtain their compositions in dust and gas-rich disks around young stars. The planet forming process is intimately linked to the disk chemical structure. First, chemistry shapes the outcome of planet formation, including planetary hospitality to life. Second, the chemistry is sensitive to the distribution of dust and pebbles in disks, and as planets open up disk gaps they may change the chemical environment within which they form. Third, molecular emission is often the only tool we have to explore disk ionization levels, kinematics and mass distribution, all key ingredients of planet formation models. We propose a Large Program to map out the radial and vertical disk chemical structures at 10 au scales, in five disks where dust sub-structure is detected and planet formation appears to be ongoing. The resulting data will give us access to the chemistry in the planet forming zone of disks, explore how ongoing planet formation shape the disk chemistry environment, and constrain the disk gas properties in the previously unexplored inner disk midplane. | Disks around low-mass stars | Disks and planet formation | 2021-02-06T21:13:05.000 |
| 1583 | 2016.2.00046.S | 334 | WISDOM: From (Giant) Molecular Clouds to Supermassive Black Holes | Supermassive black holes (SMBHs) are key to understand galaxy evolution, but the SMBH mass-central velocity dispersion relation underpinning our understanding is based on a relatively small number of measurements and a handful of methods. We have shown that it is straightforward to estimate the mass of SMBHs in the ALMA era, by probing the near-Keplerian rotation of molecular disks around them at high angular resolution. As part of mm-Wave Interferometric Survey of Dark Object Masses (WISDOM), we have identified numerous promising targets from high resolution (0.1") dust imaging with HST, and hereby request low spatial resolution (5.4") CO(2-1) imaging of 21 galaxies across the Hubble sequence. We aim to 1) quantify their molecular gas content, thus identifying the best targets for SMBH measurements at higher resolution, and 2) study the properties of the spatially-resolved molecular cloud populations analogously to the local universe, where constraining the diffuse emission is essential. Our work will revolutionise studies of the co-evolution of SMBHs and galaxies, and systematically probe molecular cloud properties in the central bulge-dominated regions of many galaxies. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2018-08-11T18:06:50.000 |
| 1584 | 2015.1.01543.T | 20 | Unlensed HyLIRG systems from the South Pole Telescope 2500deg^2 survey | From a 2500 degree^2 survey, the South Pole Telescope (SPT) has detected at 1.4mm, ~100 bright high redshift star forming galaxies, with APEX/LABOCA and Herschel/SPIRE followup. Most of these are strongly lensed ULIRGs, however a few are candidates for unlensed, hyperluminous galaxies. We propose to map the extreme z=4.30 Hyper-luminous galaxy system, SPT2349-56 using Band-3 CO(4-3) Band-4 CO(7-6) & [CI], and Band-7 [CII]. SPT2349-56 is completely unlensed, and is the current record holder for the most luminous system (in a 20" beam) in the Universe. Our observations will characterize this systems, going well beyond the ALMA subcomponents already detected in a Band-7 mapping program. Our main scientific goals are (1) detect all subcomponents in continuum and lines which make up the S870=60mJy from single dish measurements; (2) confirm the likely nature of this sytems as group/clusters caught in the act of forming massive galaxies; (3) detect continuum and CO lines from additional faint S850~1-2mJy sources identified in the Band-7 imaging (and beyond), completely characterizing this system in dust and molecular gas. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2018-03-02T03:06:05.000 |
| 1585 | 2017.A.00021.T | 21 | Radio Polarlimetry of GRB Afterglows | We have been monitoring the extremely bright GRB171205A afterglow in mm/submm band using SMA and ALMA (both 7m and 12m arrays). With our approved Cycle 5 program (2017.1.00801.T), we have also successfully conducted the radio afterglow polarimetric observation for the first time. Our coordinated SMA monitoring at 230 GHz reveals that unexpected brightening of the afterglow around 20 days after the burst, which would revise the total explosion energy. We therefore request additional two epochs of follow-up observations in early to mid of January. | Gamma Ray Bursts (GRB) | Cosmology | 2018-07-16T06:54:22.000 |
| 1586 | 2016.1.01123.S | 176 | Formation and early evolution of embedded proto-clusters | Contrary to the classical paradigm for cluster formation, recent numerical and observational results suggest that both stars and gas are independently virialized during the early stages of cluster evolution. Combining the spatial resolution and large-scale mapping capabilities of the ALMA ACA + TP arrays as stand alone interferometer, here we propose to investigate the internal structure of a selected subsample of 6 intermediate-mass clusters in the Orion A cloud. Using different ALMA Band 3 millimeter line tracers for both the dense and diffuse gas components, we expect to systematically characterize impact of the mass inflow and stellar feedback on the evolution of these proto-clusters. In addition to previous VISTA, Spitzer, Herschel-Planck, and APOGEE results in these regions, we aim to statistically test the most recent theoretical predictions of our simulations for embedded clusters comparing the dynamical state of both stellar and gas components in these young stellar systems. | Intermediate-mass star formation | ISM and star formation | 2019-10-08T00:00:00.000 |
| 1587 | 2021.1.00225.S | 298 | Mapping Obscuration to Reionization: A blank field 2mm survey in COSMOS | We propose 36 hours of band 4 (2mm) time to extend the Mapping Obscuration to Reionization (MORA) Survey to a 0.2deg^2 region in COSMOS to 90uJy/beam RMS (`Ex-MORA') with these goals: (1) Detect ~20 new z>4 dusty star-forming galaxies (DSFGs) to directly constrain the galaxy infrared luminosity function (IRLF) beyond z>4 and ~double the number of known unlensed DSFGs at z>4. Though some DSFGs are known out to z~7, their volume density is unconstrained and requires an unbiased census which gives volume density constraints. (2) Measure the average ISM masses of Epoch of Reionization (EoR) galaxies and the cosmic molecular gas budget through 2mm stacking to z~8 with a sensitivity of ~10^9Msun. Ex-MORA will be covered by deep JWST imaging (from COSMOS-Webb and PRIMER) leading to the detection of thousands of new EoR galaxies in the Ex-MORA footprint. Mapping at 2mm rather than ~1mm provides significant advantage for the z>3 Universe as the negative K-correction filters out dusty galaxies at lower redshifts. The rich set of ancillary data in the center of COSMOS will give detailed constraints on detections, allowing direct refinement of the IRLF close to and embedded within the EoR. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-01-11T23:08:57.000 |
| 1588 | 2023.1.00334.S | 0 | Measuring accurate gas masses for the exoALMA planet-forming disks | The gas mass of planet-forming disks is a crucial ingredient for our understanding of planet formation. We propose to measure accurate gas masses for the 15 sources in the ALMA large program exoALMA, ALMA's first exoplanet hunting campaign, by observing N2H+ 3-2 in the 11 sources where this line has not yet been observed. Measuring gas masses is difficult, with the most readily available gas mass tracer, CO, having been shown to have up to two orders of magnitude uncertainty due to a lack of constraints on the CO abundance. N2H+, a chemical tracer sensitive to the CO abundance, was recently shown to observationally measure the CO-to-H2 ratio and gas disk mass when combined with CO isotopologue lines, providing a path to measuring accurate gas masses. We will combine the requested observations with archival N2H+ and CO observations to measure gas masses and CO-to-H2 ratio for the 15 exoALMA disks, the sample of disks most thoroughly searched for exoplanets with ALMA and with the best characterization of these planets. Linking these two, the gas reservoir and the young planets that are actively forming in it, will provide a massive leap in our understanding of planet formation. | Disks around low-mass stars | Disks and planet formation | 2025-04-08T20:51:04.000 |
| 1589 | 2017.1.00815.S | 40 | A Wide, Deep Dense Gas Map of M100 to Connect Extragalactic and Galactic Dense Gas Results | Resolved observations of nearby galaxies and the Milky Way's Central Molecular Zone suggest an environment-dependent role for dense gas in star formation. These results conflict with current work on the Solar Neighborhood, which finds a uniform dense gas star formation efficiency. To help resolve this tension, we propose to make the first resolved observation of emission from spectroscopic ``dense gas tracers'' (HCN, HCO+, CS) that spans from the center of a galaxy all the way out to conditions similar to those found in the Solar Neighborhood. This will test the theoretical idea of a threshold ISM pressure above which clouds couple to their environment. And it will link the two major bodies of work on dense gas: extragalactic and Milky Way. We target NGC 4321 (M100), a very well studied nearby galaxy with dynamical features similar to the Milky Way. We have already studied the inner part of the galaxy and shown that the key trends exist. We are now in a position to make the first full galaxy, resolved dense gas map. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-12-02T15:11:34.000 |
| 1590 | 2021.1.01722.S | 18 | Revealing the Formation of Cold Supernova Ejecta Dust at the Center of SNR 0540-69.3 | Core-collapse supernovae (SNe) are thought to be the main source of dust in the early universe; however, the mechanism of SN dust formation is poorly understood. SNR 0540-69.3 is the youngest plerionic supernova remnant (SNR) in the Large Magellanic Cloud, and it is called a twin of the Crab due to its pulsar wind nebula (PWN). Spitzer and Herschel fluxes indicate the presence of dust at the center of this SNR, but their angular resolutions are insufficient to resolve the dust clumps. The archival ALMA Band 3 image shows detailed structures of this PWN, including bright clumps around the pulsar, and extended filaments apparently aligned along a CSM, but dust emission is too weak at this frequency. To reveal the distribution of cold dust in SNR 0540-69.3, we request ALMA Band 6, 8, and 10 observations. We plan to use the Band 6 and the archival Band 3 images to construct a map of synchrotron spectral indices, and then use it for background subtraction to reveal dust emission in Band 8 and 10 images. We expect to resolve the clumps and filaments of cold SN ejecta dust, and obtain a unique sight to understand the roles of PWNe and circumstellar media on SN dust production. | Supernovae (SN) ejecta | Stars and stellar evolution | 2023-08-09T03:27:38.000 |
| 1591 | 2016.1.00464.S | 29 | Determining the chemical origin of gas-phase methanol in the TW Hya protoplanetary disk | Detecting complex organic molecules (COMs) in protoplanetary disks is a "holy grail" for astrochemistry, because it links the complexity observed towards protostars with that in comets. The ALMA era has shone light on COMs in disks with the first detections of gas-phase methyl cyanide, CH3CN, in MWC 480, and methanol, CH3OH, in TW Hya. As a COM with an ice-chemistry origin, CH3OH is a powerful probe of the location and abundance of the disk ice reservoir, and of the non-thermal desorption mechanisms required to release it from the grain surfaces. We will observe four transitions of gas-phase methanol which span a range of upper level energies (17-40K), with a spatial resolution of 0.5" (25AU) and a high sensitivity (< 2mJy/beam) to constrain its radial and vertical location in TW Hya. Parametric modelling to reproduce the spatially and spectrally resolved line emission will reveal its location and abundance, and chemical models will determine if theorised processes (e.g. photodesorption) are responsible for its chemical origin. These data are critical for robust determinations of the likelihood of using ALMA to detect COMs of even higher complexity in solar-analogue disks. | Astrochemistry | ISM and star formation | 2018-04-26T09:44:43.000 |
| 1592 | 2019.2.00033.S | 20 | Atomic carbon in a prototypical barred-spiral galaxy M83 | Atomic carbon (CI) has been proposed as a tracer of molecular mass alternative to CO, especially in high-redshift galaxies where cosmic-ray induced reactions can destroy CO, or in outflows where the optical depth of CO is unknown. However, the CI abundance with respect to H2 varies with many other factors such as turbulence, cloud age, UV field, and density. We first need to understand how the CI abundance changes in a nearby galaxy where the physical conditions are well known. We propose to map the closest and brightest face-on barred-spiral galaxy M83 in CI over 5.2kpc x 5.7 kpc covering various galactic structures such as the galactic center, bar, arm, and interarm. We will examine the variation of the ratio between two major forms of carbon, CI and CO, among these galactic structures and examine the influence of turbulence, cosmic rays, and UV radiation. We already have larger and deep ALMA maps of CO 1-0 and 2-1. We will also compare the chemical state from CI/CO with the excitation inferred from CO(2-1)/(1-0). Our detailed analysis in M83 will serve as the best reference for CI studies in galaxies under the wide variety of physical conditions we cover. | Starbursts, star formation | Active galaxies | 2022-07-28T08:09:36.000 |
| 1593 | 2018.1.01488.S | 48 | A 150-pc Precessing Molecular Jet in the S0 Galaxy NGC1377: Outburst from an Accreting SMBH II | We propose high (0."05= 5 pc) resolution Band 6 and 9 and moderate (0. "2=20 pc) resolution Band 3 ALMA observations of the centre of the unusual S0 galaxy NGC1377. With ALMA we discovered a highly collimated, precessing molecular outflow in NGC1377. We have recently imaged the jet at 2 pc resolution, revealing an extremely collimated jet of turbulent gas. The jet signals an unexplored and transient phase in the feeding of a supermassive black hole (SMBH). By mapping in the CO6-5, SiO, CO, HNCO and HCN emission we will trace different physical conditions allowing us to probe separate components of the nucleus and jet. We aim to (1) determine the jet's driving mechanism and search for the elusive torus; (2) study evolution of the gas in the jet and search for signs of dense gas and star formation; (3) investigate if the precession is caused by a misaligned accretion flow. This evolutionary phase should be extremely short-lived, which can explain other features of NGC1377, including its extraordinarily weak radio emission (far below the FIR-radio correlation). NGC1377 presents a prime opportunity to study the interplay between SMBH growth and feedback in unprecedented detail. | Outflows, jets, feedback | Active galaxies | 2022-07-01T17:06:36.000 |
| 1594 | 2016.1.00572.S | 8 | A first look at the quiet Sun with ALMA | The chromosphere, even the quiet one, is still not fully understood. Observations at mm wavelengths provide a unique chromospheric diagnostic. We propose to carry out center-to-limb observations at two frequencies (Bands 3 and 6) and perform detailed tests of 3D models of the quiet chromosphere. Our observations will shed light on thethermal structure of the quiet chromosphere by comparing them with state-of-the-art radiative MHD simulations and simultaneous imaging and spectral observations in optical, UV, EUV, and X-rays. We will assess whether the models can reproduce the mm observations and in case of discrepancies we will investigate their origin and how the models could be adjusted. The comparison of observations and models will also help us clarify the role of spicules in the limb brightening. The Band 3 observations will also be appropriate for the study of weak transient activity. These events may have a bearing on the heating of the upper atmosphere. Their occurrence rate will be compared with that of similar events that will be detected by the instruments that we have arranged to be co-observing with ALMA. | The Sun | Sun | 2018-07-26T00:00:00.000 |
| 1595 | 2018.1.01081.S | 160 | M0.10-0.08: A Local Laboratory to Study Shocked Gas in Extreme Environments | Shocked gas is often observed in the inner 400 pc of gas rich galactic nuclei. Our Galactic center provides a unique opportunity to study shocked gas in molecular clouds at sub-parsec scales. We propose to study a compact molecular cloud, M0.10-0.08, which has elevated emission in several 3 mm shock tracers (e.g., SiO, HCN) in single-dish observations (Mills & Battersby 2017). However, the source of the shocked emission is up for debate. M0.10-0.08 is located near two possible mechanisms for this shock activity: an interaction between an expanding bubble and a gas stream (Butterfield et al. 2018) or a gravitational tidal compression (Kruijssen et al. 2015). The low-resolution of the single-dish observations are unable to determine the morphological structure of the shocked gas. Our proposed ALMA observations will be able to determine the location and kinematics of the shocked emission and determine which mechanism is producing the shocked gas in this cloud. By understanding the mechanisms producing shocked gas in this cloud, we will be able to better understand observations of shocked gas in external galactic nuclei. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-07-06T00:41:33.000 |
| 1596 | 2017.1.01457.S | 25 | Do Molecules Condense in the Wind of the Nearest Lyman Break Analog Galaxy? | The intergalactic medium was enriched with metals early in the age of the universe. These metals originated in low mass galaxies and were dispersed by galactic winds. While the shallow potential wells of these galaxies made baryon retention difficult, winds are not only subject to gravitational forces: cooling and dissipation of their bulk kinetic energy strongly limits their ability to escape. Lines that probe molecular gas are crucial for understanding the evolution of winds because this gas is the ultimate dissipative reservoir of kinetic energy via slow molecular shocks. To understand the role molecular gas plays in dissipation, we proposal to observe [CI](1-0) in the nearest analog of Lyman break galaxies in the early universe, Haro 11. Focusing on regions were gas is rapidly cooling between the warm ionized medium and warm neutral medium, we will probe the cooling and dissipation rate in the cold neutral/molecular media. Comparing these rates to our vast multiwavelength data set and kinetic energy output of the starburst, we will constrain the fractional energy lost in the molecular gas and take another step in determining the fate of winds from galaxies. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2019-06-06T13:23:50.000 |
| 1597 | 2023.1.01327.S | 0 | Propagation of cosmic rays in molecular clouds interacting with a supernova remnant | Cosmic rays (CRs) are a major component of the Galaxy. Especially, since low-energy CRs lose their energy via ionization, they are believed to have a strong influence on the chemical evolution in molecular clouds and on star and planet formation. However, the influence of CRs has been discussed only hypothetically in theories because the propagation process of CRs in molecular clouds is highly unknown. A recent study noted that CR protons with E~0.01 MeV, ~10 MeV, ~GeV attribute to the ionization rate, Fe I Ka line, and Gamma-ray emission, and indicated that the relative spatial distributions among the the three observables are the key to reveal the propagation process. Actually, there are no samples where the three observables were measured in the same region. We focus on the southwestern edge of the supernova remnant W44, where both the Fe I Ka line and gamma-rays are detected. We propose DCO+ (J=2-1) and H13CO (J=1-0) observations at two positions in this region to measure the ionization rate and its spatial distribution. This observation will reveal the propagation of MeV CRs observationally for the first time. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-11-17T08:30:15.000 |
| 1598 | 2022.1.01314.S | 110 | ACA CO 1-0 Maps to Match MeerKAT 21-cm Maps | Stars form from molecular gas, while most of the gas in galaxies is atomic gas, making the transformation of HI to H2 and the phase balance of the ISM one of the key elements in understanding galaxies. The SKA pathfinder MeerKAT is now the premier telescope to map 21-cm emission from southern galaxies. We propose ACA-only CO 1-0 mapping of 10 galaxies that are currently obtaining ultra-deep, high quality 21-cm maps of MeerKAT's Large Survey Project MHONGOOSE. This will create a paired ALMA CO and MeerKAT 21-cm data set that we will use to make new measurements on a series of important, but recently neglected topics: comparing the kinematics and stability of the molecular and atomic phases, measuring how the star formation law depends on ISM phase, and testing and improving prescriptions to predict and explain the balance of atomic and molecular gas in galaxies. With this proposal, ALMA will have produced CO maps for half of these key MeerKAT targets, a major step towards building synergy between these two facilities. | Spiral galaxies | Local Universe | 2024-03-06T21:37:13.000 |
| 1599 | 2017.1.01387.S | 133 | Understanding the nature of the ULIRG population in massive clusters at z ~ 1-1.5 | Mid/far-infrared and submillimeter surveys of z~1-1.5 clusters have found apparent over-densities of dust-obscured, but strongly star-forming galaxies within some cluster cores. We have completed a 870um survey of ten massive z~1-1.5 clusters with SCUBA-2 finding a wide range of activity within their cores. Using ALMA to map an over-density of four SCUBA-2 submm sources in the core of a z=1.46 cluster we resolved this emission into fourteen distinct 1mm continuum sources (each possessing ULIRG-like luminosities) and simultaneously confirmed five of these as cluster members from CO(5-4) emission. We propose to use ALMA to measure the dust continuum and search for CO(5-4) line emission for ULIRGs in the central 3 Mpc of two other active clusters from our survey: RX J0152 and XDCP J0044. Using this data to examine the dynamics, molecular gas mass, star formation efficiency, and dust to gas ratio of these cluster ULIRGs to compare them to similarly luminous systems in the field and test their connection to potential descendant populations of elliptical and S0 galaxies in clusters today. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2019-06-13T15:54:38.000 |
| 1600 | 2015.1.00407.S | 11 | Fast outflows quenching star formation at high redshift | According to theoretical models, quasar driven outflows at high redshift clean massive galaxies of their gas content and quench star formation. We have recently discovered powerful AGN-driven outflows by studying the velocity field of [OIII]5007 in three quasars at z~2.4. The spatial distribution of the starforming regions in their host galaxies is anticorrelated with the presence of fast outflows, providing the very first evidence of quasar feedback quenching star formation. However, this evidence is tentative as it is based only on rest-frame optical spectra. We propose to map CO(3-2) to trace the distribution of the cold molecular gas in the three quasars, the only ones known so far showing evidence of outflows quenching star formation. The CO(3-2) maps will be compared with our [OIII] maps with similar spatial resolution: the molecular gas should be absent in the outflow dominated region, while surviving in the rest of the galaxy. This would be the first direct confirmation of star formation quenching by quasar outflows. Our ALMA observations will then open the way for the physical characterization of quasar driven feedback in larger samples of objects. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-11-04T19:08:23.000 |
| 1601 | 2016.1.00544.S | 60 | The birth of the giants: Imaging spectacular mergers at the dawn of galaxy formation | Through a low-resolution ALMA snapshot survey of [CII] emission in QSO host galaxies at z>6 (within 1 Gyr of the Big Bang), we have unexpectedly identified four QSOs that show gas-rich companions at close (projected) separations. The implications of detecting interactions/mergers of gas-rich galaxies at such high redshift are significant, as they have been invoked in the past to explain the existence of massive `red and dead' galaxies by z~2. This sample of galaxy companions in the very early universe is the first known of this kind. Higher resolution/sensitivity imaging in the [CII] line and the underlying dust continuum is needed to investigate the on-going gravitational interactions through mapping the morphology and the kinematics of the gas. At the same time, we will constrain the dynamical masses of the QSO hosts and the companions, and map their star formation activity. Given the extreme brightness of our sources, high-resolution (0.2", 1.5 kpc) imaging of the [CII] and dust emission can be easily attained with ALMA. This will allow us to directly zoom into the build-up of the most massive galaxies at the dawn of cosmic time for the first time. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2018-02-01T16:58:47.000 |
| 1602 | 2016.1.00441.S | 63 | Probing the chromospheric heating regions of the solar analogue alpha Centauri with ALMA | Comparison of our ALMA Band 3, 4, 6, 7, 8 and 9 data for the nearby solar-typ alpha Cen with results from our semi-empirical non-LTE chromospher models suggests that the data are sensitive probes of the location of the base of the transition region toward the corona. This chromospheric temperature plateau constitutes a critical region, beyond which a dramatic increase of the temperature occurs, due to the dissibation of non-radiative energy, likely carried by acoustic and MHD waves. This scenario is similar to that inferred for the Sun and thus provides feed-back to the solar physics community, which during C4 will gain access to solar ALMA observations in Band 3. The ``quiet Sun/star'' models assume stationarity, whereas the heating processes are highly dynamic, implying variability over a wide range of the mode spectrum, in particular for the active K-star alpha Cen B. The present proposal seeks to address observationally the steadiness of these unique chromospheric ALMA SEDs of alpha Cen A and B. | The Sun, Main sequence stars | Sun | 2018-05-04T00:00:00.000 |
| 1603 | 2017.1.00575.S | 28 | Measuring line width of RRL from BLR of the Circinus galaxy | We propose to measure the line widths of radio recombination lines (RRLs) (H35a, H36a, H40a, and H42a) from broad line region of the nearby type II galaxy Circinus. Broad line emission of RRLs (H35a, H36a) in Circinus had been detected with the Cycle 3 data with limited velocity coverage, which caused the difficulty of deriving the line widths of broad RRLs. Thus, we propose to re-observe the RRLs (H35a, H36a) with two overlapped frequency tuning to have about twice velocity coverage than that in Cycle 3. Observations of H40a and H42a are also proposed to confirm the broad lines of RRLs, as well as to derive the pressure broadening, which can be used to determine the density of electron density in the broad line region. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-11-22T23:37:37.000 |
| 1604 | 2019.1.00720.S | 24 | Doubly deuterated water toward isolated and clustered protostars | Understanding the evolution of water during star formation, from the molecular cloud down to the protoplanetary disk, is a central goal of astrochemistry. The amount of deuterated relative to non-deuterated water (D2O/HDO and HDO/H2O) traces the physical and chemical evolution of water because H2O is predominantly formed in the molecular cloud while deuterated isotopologues form later in the dense core phase. As a consequence, the D/H ratio of water should differ between isolated and clustered protostars since collapse time-scales depend on physical properties of the local environment such as density and temperature. We propose to observe the D2O transition at 316.8 GHz toward three isolated and two clustered protostars. HDO and H2O column densities have previously been measured toward the five sources allowing for direct comparison between the D2O/HDO and HDO/H2O ratios. Comparing the HDO/H2O and D2O/HDO ratios will provide critical feedback to chemical models, improve our understanding of the water evolution during star formation, and show the impact of the local cloud environment on the physical and chemical evolution during star formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2021-01-24T14:50:22.000 |
| 1605 | 2013.1.01292.S | 126 | An ALMA survey to unveil the main mode of star formation in the early Universe | In recent years, convincing evidence have been accumulated that galaxies built up their stellar mass through a steady, diffuse and inefficient gas conversion dominantly taking place in non-interacting disk dominated galaxies. This has been confirmed at least up to z~3, beyond that even the deepest Herschel and JVLA surveys are not able to probe deep enough in L_IR sensitivity to detect normal massive galaxies. Thanks to exceptional ALMA sensitivity we are now in the position to easily detect a statistical sample of normal star forming galaxies at z~4 and test, for the first time, if the secular mode of stellar mass growth extends over all cosmic time. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2016-01-23T14:33:10.000 |
| 1606 | 2017.1.00545.S | 57 | How to form high-mass stars in proto-clusters? | Although high-mass stars (M >8 Msun) play a major role in the evolution of galaxies, their formation and evolution are still very unclear. The two particularly promising models of high-mass star formation are "turbulent core accretion" and "competitive accretion" (see reviews in Krumholz & Bonnell 2009; Tan et al. 2014). In order to distinguish from different models for high-mass star formation, we propose to use ALMA 12-m array to mosaic 11 protoclusters. We aim to: (1). Study the spatial distributions of individual cores and their mass assembly in the protoclusters; (2). Study infall motions of individual cores with inverse P-Cygni profiles in HCN (4-3) and HCO+ (4-3) lines (3). Reveal the population of low-mass protostellar cores to see whether low-mass stars form along with their high-mass counterparts. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2019-08-14T05:18:39.000 |
| 1607 | 2016.1.00580.S | 32 | Confusion-free Mapping of the Node within the Cosmic Web at z = 3 | The z=3.09 SSA22 proto-cluster is one of the densest field at z>2 and therefore provide an unique laboratory to understand how galaxies and supermassive black holes (SMBHs) are formed and evolved in such extreme environment. In ALMA Cycle 2, we mapped a 2'x3' region of the proto-cluster core at 1.1mm, which results in the discovery of incredibly elevated star-forming and accretion activity at the 'node' of the 50 Mpc scale 'cosmic web'. Furthermore all of the dusty starburst galaxies are along the extensively extended Lyman-alpha filaments. To uncover the dust-obscured activity at the heart of the large-scale structure thoroughly, we propose to map an additional 4'x3' region, including the density peak of the proto-cluster. Utilizing the combined 20 arcmin^2 'ALMA Deep Field', we will (i) unveil the nature of dusty star-forming galaxies (number counts, clustering, the relation to the Lyman-alpha filaments, contribution to the cosmic star-formation rate density), (ii) characterize dusty activity in various populations via stacking analysis, and (iii) uncover how galaxies and SMBHs are co-evolved within the proto-cluser core. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-07-19T08:40:45.000 |
| 1608 | 2019.2.00014.S | 0 | Line ratio mapping: recovering the Total Power in the northern filaments of Centaurus A | Centaurus A is a very well-studied nearby radio-galaxy surrounded by HI shells. The powerful radio-jet emitted by the central AGN seems to hit one of these shells, at ~15 kpc from the galaxy centre. This source is thus a perfect target to probe the phenomenon of jet-gas interaction. On top of atomic gas, we have found molecular gas and studied the ionised gas and UV emission associated to young stars at the position of the interaction, lying in elongated filaments. We now aim to study accurately the spatial variations of the cold gas physical conditions within those filaments. We propose to fully and precisely map the CO32/CO10 line ratio. In order to achieve this scientific objective, we already observed both lines with ALMA and ACA. However, we recently discovered that even ACA does not fully recover all the extended CO(3-2) emission: only half of the flux measured by APEX is retrieved. It is thus very likely that ACA does not fully recover the CO(1-0) emission either. We therefore propose to observe both the CO(1-0) and CO(3-2) lines with the ALMA Total Power only. It is the only facility able to map the full filaments with the needed sensitivity in a reasonable amount of time. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2022-05-18T20:24:10.000 |
| 1609 | 2016.1.00951.S | 11 | Filaments and Massive Star Formation | The filamentary nature of the interstellar medium and molecular clouds sparks many questions about the mass assembly of molecular clumps and the formation of dense cores within them. We investigate a nearby, cold, and massive (1300 Msun) clump embedded in the infrared dark cloud G350 in the NGC 6334 star-forming complex. The molecular line emission from NH2D and H13CO+ as well as 3mm continuum traces gas at different evolutionary stages and at a range of densities. The sensitive ALMA observations will probe the mass accretion and fragmentation of molecular clumps and dense core formation. The data from this study will inform development of theoretical models of massive star formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-04-25T19:44:05.000 |
| 1610 | 2018.1.00081.S | 57 | The first measurement of a metallicity gradient in a dust-obscured galaxy at z=4 | We propose 0.2arcsec(1.3 kpc)-resolution observations of [OIII]88 and [NII]205 lines for one of the best-studied submillimeter bright galaxies (SMGs) at z = 4.34, following our successful high-resolution observations of CO(4-3) and [CII] lines. The target, COSMOS-AzTEC-1, is a very massive, star-forming galaxy and the CO emision is concentrated on the central 1 kpc region, suggesting that AzTEC-1 is the most likely progenitors of compact quiescent galaxies at the peak of the cosmic star formation history. If the concentration of molecular gas is caused by an infall of pristine gas into the central 1 kpc region, we would see a deficit of metal-rich gas in the center. If not, metal-poor gas would be accreted onto the surrounding disk, supporting a scenario that the most massive galaxies grow from inside out. The primary goal of this proposal is to measure the gas-phase metallicities in the very bright, compact SMG using [OIII]/[NII] ratio. We will for the first time explore the metallicity gradient in such a heavily dust-obscured galaxy to constrain the scenarios of gaseous processes. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-12-18T11:59:02.000 |
| 1611 | 2016.1.00550.S | 33 | (How) do very massive stars form in our Galaxy? | Sgr B2 is the densest region of star formation in the Galaxy, and it is therefore the most likely to form the most massive stars in the local universe. Such proto-very massive stars (proto-VMS) may accrete from significantly different structures than the ordered disks we are accustomed to observing around nearby low-mass stars. We propose ALMA long-baseline observations to identify these structures and determine their masses and kinematic properties. We will determine whether the most massive stars, at least in our Galaxy, form by a scaled-up process similar to low-mass stars or by a more complex competitive or cooperative accretion process. We will also search for clues about whether stellar mergers are responsible for creating VMS. | High-mass star formation, HII regions | ISM and star formation | 2018-10-13T18:53:40.000 |
| 1612 | 2017.1.01419.S | 170 | Planet formation in sparse stellar groups | A significant fraction of the stars are born in sparse stellar groups of 10-100 stars. While the unprecedented sensitivity of ALMA has allowed to study the gas and dust masses and surface density profiles of many disks in star forming regions containing > 100 members, little is known about disks in sparse stellar groups. Constraining their properties is important as environmental conditions have an impact on disk evolution, which in turn will affect planet formation. For example, if disks in sparse groups are very extended (as expected from simulations), they could be the precursors of giant planets at large orbital distances. Here we propose to resolve the continuum and gas components of 10 selected gas rich disks in Epsilon- and Eta- Cham, the only sparse stellar groups within 250 pc with mean ages below 10 Myr. Given the age, distance, accretion levels, and SEDs, our sample comprises the best targets to study in detail disks in sparse stellar regions. We will test if these disks are different than those in crowded regions. | Disks around low-mass stars | Disks and planet formation | 2019-11-22T16:26:32.000 |
| 1613 | 2016.A.00011.S | 0 | Resolving the Chemical and Physical Structure of the Disk Forming Zone in L1527 | This is a resubmission of the Cycle 2 proposal (2013.1.00858.S), which was evaluated as ranked-A. However, this program has not been completed due to the faults of the alma staff. So, we request the DDT observations to complete the original science goal proposed for cycle 2. We aim to resolve the transition zone between the infalling rotating envelope and the inner disk in the low-mass Class 0 protostellar core L1527 at a high angular resolution. With our ALMA Cycle 0 observations, we recently discovered a drastic chemical change in the transition zone around the centrifugal barrier (100 AU in radius). Carbon-chain molecules and their geometrical isomers reside mainly in the infalling rotating envelope, while SO preferentially traces the transition zone. Such a phenomenon seems to be caused by the accretion shock in front of the centrifugal barrier. Detailed exploration of the shock structure at a high angular resolution is thus an important and urgent issue for understanding the disk formation. This observation will put a stringent constraint on chemical evolution from protostellar cores to protoplanetary disks. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-03-28T18:01:28.000 |
| 1614 | 2015.1.01541.S | 23 | Anchoring Spiral Galactic Magnetic Fields in Molecular Clouds | The formation of molecular clouds is poorly understood. Many cloud formation models assume that a large-scale galactic magnetic field is irrelevant at the scale of individual clouds, because the turbulence and rotation of a cloud may randomize the orientation of its magnetic field. The only observation of cloud fields in a face-on galaxy (M33, Li & Henning, Nature, 2011), however, supports the opposite picture: galactic fields could be strong enough to impose their direction upon individual clouds, thereby regulating cloud accumulation and fragmentation. Our location in the disk of the Galaxy makes an assessment of the situation difficult and observations of clouds in face-on galaxies are necessary. Only ALMA can offer the resolution and sensitivity to survey magnetic fields of clouds in face-on galaxies using the polarization of thermal dust emission. In this proposal, we start with NGC 628, a bright grand design spiral galaxy in the southern sky. | Spiral galaxies | Local Universe | 2018-02-16T01:10:49.000 |
| 1615 | 2019.2.00035.S | 9 | Understanding how CI, CO and dust trace molecular gas in z=0.35 normal star forming galaxies | We propose CI(1-0) and dust imaging in 6 galaxies at z=0.35 which are part of a sample imaged in Cycle 1 at higher angular resolution. Our Cycle 1 project (2012.00978.S) was the first set of observations of dust, CO(1-0) and CI(1-0) in 12 normal galaxies, forming a statistically complete sample selected at 250 microns, and aims to determine a calibration for molecular gas using all three tracers for the first time. The Cycle 1 results are surprising, with 50% showing disturbed kinematics, either due to interactions with small satellite companions or potential outflows. The range of L_CI/L_CO ratios spans the full range of values seen in quiescent clouds in the Milky Way to extreme SMG and QSO, yet these galaxies are unremarkable systems with 11.1< Log Lir < 11.7, and so we do not understand what drives this variation. The limitations of Cycle 1 mean we have very different u-v coverage for the band 3 and 7 data-sets, therefore we request Band 7 ACA for the CI and dust in 6 sources with extreme CI/CO ratios, or where the CI and dust emission may be missing flux in extended structures. These ACA data will enable a robust morphological comparison between the CO, CI and dust emission. | Spiral galaxies, Merging and interacting galaxies | Local Universe | 2021-04-09T12:39:18.000 |
| 1616 | 2022.1.01178.S | 0 | The ISM distribution, gas kinematics and system dynamics of five rotation-dominated quasar-starburst systems at z > 6 | We propose ALMA band-6 observations of the [CII] line along with the dust continuum emission toward five z > 6 quasar-starburst systems at resolutions of 0.042" to 0.09" (physical sizes of 250 to 500 pc at the quasar redshifts). We reduced ALMA archival [CII] data of ~100 z~6 quasars, and selected five objects that are [CII]-brightest and rotation-dominated quasar-starburst systems. With the proposed high resolution ALMA [CII] observations combined with archival short-baseline [CII] data, we will study the spacial distribution and the extent of the ISM, the resolved [C II]-FIR deficit, and the heating mechanism of the dust. With 3D tilted ring kinematic modeling, we will study the gas kinematics in the sub-kpc to kpc regions, and search for evidence of non-circular motions. Through dynamical modeling, we are able to investigate the composition and the distribution of mass matters in these quasar-host systems. Especially, we will have the dynamical measurements of the black hole masses in the earliest Universe for the first time. In addition, we will investigate the coevolution of quasars and their hosts across cosmic time. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-04-06T08:12:04.000 |
| 1617 | 2015.1.00122.S | 17 | Gas and dust in the most luminous Lyman-alpha emitter at the epoch of re-ionisation: PopIII? | We have recently discovered, and spectroscopically confirmed, the most luminous Lyman-alpha (Lya) emitter ever found, located well into the era of re-ionization (CR7, z = 6.604, L(Lya)=10^43.9 erg/s; Sobral+2015, arXiv:1504.01734). Near-infrared spectroscopy reveals the presence of a strong HeII164nm emission line (6 sigma) with narrow FWHM (130 km/s, thus disfavouring AGN and WR stars) and absence of metal lines, suggesting the presence of PopIII (metal-free) stars. We can only fit the SED of CR7 with a 2-component model consisting of i) PopIII and ii) a chemically enriched population, with each contributing 80% and 20% of the total UV light, respectively. HST/WFC3 observations confirm that CR7 consists of different components (A, B, C), separated by ~5kpc. The brightest (A) dominates the UV and may be PopIII-dominated, while B+C are likely enriched. Our extraordinary interpretation (finding metal-free stars for the first time) requires the most stringent tests. We therefore propose to target CR7 with ALMA in the [CII] line and the adjacent dust continuum, to test if any sign of metal enrichment (Carbon and/or dust in the ISM) can be found in this object and, if so, where. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2017-12-30T20:43:18.000 |
| 1618 | 2021.A.00031.S | 30 | The puzzling JWST object timely distangled by ALMA: Dusty starburst at z~5 or Ultra high-z galaxy at z~17? | JWST has sparked a revolution of effort to discover and study galaxies at very early cosmic epochs. In particular, remarkably bright z~17 galaxy candidates are identified from several teams, which, if real, defies every early galaxy evolution model that assumes Lambda CDM cosmology. However, the latest study reports a tentative SCUBA2 850um detection from one of these candidates and shows that a z~5 dusty starburst galaxy with strong nebular emission lines can make its JWST/NIRCam broadband photometry at 1-5um resemble the extreme high-z galaxy SED. Here we propose a timely 1-hr ALMA Band 7 follow-up via DDT for such a z~17 galaxy candidate to confirm/rule out the lower-z scenario. Rather than waiting for the regular call, validating the robustness of first galaxy candidates at the farthest frontier is of urgent importance to the community in designing the next generation of follow-up observations, including ALMA cycle10 in April 2023 and JWST cycle2 in January 2023. Given this aspect, we waive the proprietary period of this DDT program. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2022-09-28T09:48:18.000 |
| 1619 | 2016.1.01253.S | 42 | Origin and evolution of atomic gas in debris discs - A new way of studying planetary systems | Thanks to ALMA, CO has been detected around a few main sequence stars with infrared excess. This comes as a surprise as debris discs were expected to be gas free. In most of these systems, CO is thought to be secondary gas produced from the solid bodies of debris belts. CO is then quickly photodissociated by impinging UV radiation and transforms to C+O that viscously evolves spreading all the way into the star. Kral et al. (2016) created the first self-consistent model of the evolution of such atomic gas in debris discs and can explain all gas observations of Beta Pic. The model now needs to be tested for other systems with different spectral types, CO production rates, ... To do so, we need to observe C I in other systems and we have chosen the best two targets to realise this test. These observations will definitely tell us whether the mystery of the origin and evolution of gas is now solved. C I observations would not only confirm our scenario but is also a new avenue to extend our knowledge of inner regions of planetary systems where terrestrial planets are located... | Debris disks | Disks and planet formation | 2018-04-21T17:03:48.000 |
| 1620 | 2012.1.00797.S | 0 | Deciphering black hole feedback: molecular outflow in an obscured quasar | We propose to complete our search for outflowing molecular gas in the obscured quasar SDSS J1356+1026, which was ranked as a top-priority project in cycle 0, but has not been observed.This nearby (z=0.123) luminous quasar is blowing a 20 kpc-scale bubble of ionized gas, and provides strong evidence that black holes can inject energy into their large-scale environments without the help of star formation or radio jets. The bulk of the outflow may well be in the molecular phase, and we will search for it with CO(1-0) and CO(3-2) observations with ALMA. With one hour of integration, we will probe the majority of the outflowing mass and reveal the physial conditions of the outflow. SDSS J1356+1026 provides a key to understanding the prevalence of black hole energy injection in the growth and evolution of galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2015-04-17T13:13:49.000 |
| 1621 | 2018.1.00503.S | 119 | The galaxy-wide impact of powerful feedback in ULIRGs | In recent years, the SPIRE Fourier Transform Spectrometer (FTS) has enabled observations of high-J CO transitions (J = 5 to J = 13) for a large number of local Ultra Luminous infrared galaxies (ULIRGs). These observations have been successfully used, together with low-J CO, mid-IR and far-IR spectral lines, in radiative transfer modeling codes (such as RADEX) to determine the relative contributions of Active Galactic Nuclei (AGN), star formation, and mechanical heating to the energy budget, and to constrain the density, temperature and column density in different phases of the interstellar medium (ISM). While such studies abound for local ULIRGs, they include only 3 sources hosting strong molecular outflows, a key step in quenching star formation in the outflow host galaxy. Here, we propose to observe low-J CO lines from 9 local ULIRGs hosting powerful molecular outflows, which have near-complete observations of the mid/high-J CO lines, as well as mid-IR and FIR spectroscopy, in order to complete their CO SLED from J = 1-0 to J = 13 - 12. This will be the first statistical test for any galaxy-wide changes to the ISM and star formation in ULIRGs as a result of molecular outflows. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-10-26T21:52:44.000 |
| 1622 | 2021.1.00181.S | 11 | Molecular gas and obscured SFR in a typical sub-L* galaxy at z=6 | Accurate estimates of the mass and properties of the cold gas in distant normal star-forming galaxies are the key to understand how they grow, but also a challenge at z~3-6 due to their faintness. Here we propose an in-depth analysis of a strongly lensed sub-L* galaxy at z=6 to measure its molecular gas and obscured SFR content. The [CII] emission securely identified two lensed images in the ALMA Large Cluster Survey due to their magnification (20-160). The target is intrinsically faint and representative of low-mass galaxies at the end of reionization (M*~1e9 Msun, SFR~5 Msun/yr, much lower than any [CII]-detected source at z~6). We will (1) determine the molecular gas mass using [CI](2-1) and the dust in the Rayleigh Jeans tail, cross-calibrating the estimates from [CII], CO(1-0) (scheduled at VLA), and the dynamical mass (with ALMA+approved JWST); (2) estimate the obscured SFR via the LIR-L'CO(7-6) relation and by modeling the dust emission; (3) provide a benchmark (also on resolved scale) for the ISM conditions and the dust temperature in typical sub-L* galaxies at z=6 with CO/CI/CII and continuum ratios, creating a reference template for future studies of statistical samples. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2023-02-08T16:41:28.000 |
| 1623 | 2022.1.01587.S | 5 | ALMA reveals a [CII] radio-driven kpc-scale outflow at z~6 | The interactions between radio jets and the interstellar medium are thought to play a defining role for the co-evolution of supermassive black holes and galactic stellar masses. However, observational constraints on these feedback processes are still very limited at z~2 and non-existent beyond z>4, where theoretical galaxy formation models can be best constrained. Recent ALMA observations have revealed evidence of a collimated [CII] emission, with similar morphology, extent, and position angle to a ~2kpc jet in a radio-bright quasar at z~6. This is the first evidence of a [CII] outflow driven by a radio jet at these redshifts. However, the limited significance (2-4sigma) of the emission prevents a detailed analysis of this unique system. Here we propose deep 0.04" (~300pc) resolution that will allow us to test directly how the radio jet is affecting the dust and gas in the host galaxy. We will quantify for the first time the effects of radio jets during the formation of a massive galaxy within the first billion years of the universe. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-08-18T17:47:26.000 |
| 1624 | 2021.1.00045.S | 0 | The surface magnetic field of AGB stars: Zeeman measurements of atmospheric OH | Magnetic fields appear ubituitous throughout the circumstellar envelopes (CSEs) of evolved asymptotic giant branch (AGB) stars. However, the magnetic field strength on the surface of AGB stars is very poorly constrained. It is the magnetic field near the surface that will possibly affect the stellar mass loss and hence evolution. So far only one AGB star has had its surface magnetic field measured using observations in the visible and very few other AGB stars are accessible with this technique. Maser observations have revealed strong magnetic fields in the CSEs, but it is unclear if these measurements can be extrapolated to the star. Recently, ALMA discovered non-masing excited OH in the atmosphere of AGB stars. The magnetic succeptibility of OH means that there is now a direct probe of the magnetic field near the stellar surface. Here we propose to detect the magnetic field of the AGB star W Hya for which maser observations imply a field of several Gauss near the surface. If we can confirm this field we can, for the first time, benchmark the maser measurements in the CSEs with the surface field and determine if the magnetic field has the power to affect the mass loss mechanism. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2023-08-04T19:29:58.000 |
| 1625 | 2021.1.00546.S | 35 | Unveiling the kinematics of a highly dense prestellar core with substructures at 1000 au scale | Prestellar cores (PSC) are self-gravitating dense and cold structures within molecular clouds where future stars are born. They are expected, at the stage of transitioning to the protostellar phase, to harbor centrally concentrated dense (sub)structures that will seed the formation of a new star or the binary/multiple stellar systems. Characterizing this critical stage of evolution is key to our understanding of star formation. In a rare detection, recently dense 'kernel'(~2000 au) and substructures are reported towards an Orion PSC G205-M3. However, it is unclear how the structure and substructures form in the prestellar core (PSC), and the role of gravity and turbulence in producing the substructures. To this end, we propose high-resolution ALMA observation using N2H+ and N2D+ to measure the temperature profile, kinematics, and velocity dispersion in the central dense region of the PSC. These molecules do not suffer depletion in the dense region, and using the high-resolution ALMA observation for the first time we will be able to unveil the fragmentation mechanism and kinematics of the PSC at the onset of collapse and star formation. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-02-10T15:32:59.000 |
| 1626 | 2023.1.00521.S | 0 | Quiescent or Not? Deep ALMA Observations of a Quiescent Galaxy at z=7.3 | We propose ALMA Band 6 observations to detect the [CII]158um line and dust continuum of the highest confirmed redshift quiescent galaxy at z=7.3. The galaxy shows no signs of recent on-going star formation based on its rest-optical emission line-free JWST/NIRSpec spectrum. The spectroscopic redshift has been confirmed by prominent optical absorption lines. SED-fitting results suggest a recent starburst at 5-10Msun/yr about 50Myrs in the past. Its low stellar mass (5e8Msun) suggests expulsion of gas through winds/feedback or stripping through galaxy-galaxy interaction as likely causes if its current state. But is this galaxy really quiescent? And why? With the proposed ALMA observations, we aim at answering these questions by (i) measuring its obscured star formation, (ii) constraining its gas reservoir and circumgalactic metal enrichment, (iii) finding potential signs of outflows (that could have led to the expulsion of gas), and (iv) characterizing its immediate environment as probed by dust-obscured companion galaxies. These observations are the first of its kind, starting the era of studying quiescent galaxies at very high redshifts through a synergy between ALMA and JWST. | Galaxy structure & evolution | Galaxy evolution | 2025-08-26T19:34:58.000 |
| 1627 | 2013.1.00266.S | 14 | HMSFSiO | We propose ALMA high-angular resolution and high sensitivity observations of SiO v=1, J=2-1 maser lines toward new SiO maser sources of 2 high-mass star-forming regions, G19.61-0.24A and G75.78+0.34 which are detected by the Korean VLBI Network single dish telescope. Through the ALMA observations, we investigate the exact positions and spatial distributions of SiO v=1, J=2-1 maser emission. We also expect to investigate the inner part of jets/outflows which regions are playing an important role for launching and collimating the jets/outflows probably related with rotating accretion disks close to the central protostars. In addition, the observational results of several transitions of CH3OH masers, SiO thermal emission, and continuum etc. are compared with those of SiO masers. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2015-11-19T13:20:10.000 |
| 1628 | 2021.1.00128.L | 1087 | AGE-PRO: the ALMA survey of Gas Evolution in PROtoplanetary disks | We propose a Large Program designed to systematically trace the evolution of gas disk mass and size throughout the lifetime of protoplanetary disks, using a well-defined sample of 30 disks between 0.1-10 Myr old. Gas is the dominant mass constituent of protoplanetary disks. Its structure and evolution profoundly impact every major step of planet formation: planetesimal formation, accretion of planetary atmospheres, and migration of planets. Yet, we do not have a basic understanding of how the gas disk evolves and what mechanism drives the global evolution. This program will provide the first homogeneous and sensitive survey to constrain the evolution of the mass and size of gas disks at three evolutionary phases: the embedded disk phase, the middle-age, and the end of the disk lifetime. By combining deep observations of CO isotopologues and N2H+, we will improve the accuracy of current mass measurements by a factor 10-20, and size measurements by a factor of 5. The results will provide fundamental insights into the global evolution of protoplanetary disks, and provide a key legacy dataset to test current main theories of disk evolution and planet formation. | Disks around low-mass stars | Disks and planet formation | 2023-07-16T03:40:15.000 |
| 1629 | 2013.1.01194.S | 55 | A CF+ survey of the diffuse medium in the inner galaxy | Herschel and Planck data confirm the presence of diffuse ISM gas that is not well traced by the usual atomic or molecular probes, ie H I or CO. It can be followed in C+, in emission at 1.9 THz, but we propose a more accessible probe of C+ by following gas-phase fluorine into HF and CF+. When H2 is present, fluorine concentrates into HF exothermically via F+H2->HF+H and forms CF+ via C+ + HF->CF+ + H, making CF+ the 2nd largest fluorine reservoir where C+ and H2 coexist. Since HF tracks H2, CF+ is a perfect tracer of the H I-> H2 transition. Recent observations toward the Horsehead and the bright QSOs BLLAC and 3C111 illustrate this in the science case. We propose to use ALMA to perform an exploratory survey of CF+ absorption in the inner galactic plane using well characterized sight-lines towards continuum sources studied in the Herschel PRISMAS survey and other means. We target HOC+ simultaneously because HOC+ forms in the reaction of C+ and H2O. By comparison with the existing data, we will determine the fraction of diffuse gas in molecular form and investigate the relative contributions of atomic, molecular and ionized gas to the C+ budget. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2017-01-03T20:46:27.000 |
| 1630 | 2017.1.00078.S | 170 | Can C0/CO abundance ratio be a robust discriminator of PDRs and XDRs? -A test study in NGC 7469 | To identify energy sources of galaxies at mm/submm (least affected by dust extinction) can be an excellent way to uncover dust-obscured AGNs, which are elusive at optical. Although we have proposed that HCN abundance enhancement with respect to HCO+ can be a potential method, we here propose to test another energy diagnostics using C0 and CO lines to make an independent way to pursue. Indeed, chemical models predict a drastic (orders of magnitude!) enhancement of [CI](1-0)/13CO(2-1) ratio in XDRs than in PDRs, which reflects much higher C0/CO abundance ratio in the former. In this program, we then try to measure (i) [CI](1-0)/13CO(2-1) flux ratio, and (ii) C0/CO abundance ratio via non-LTE modellings (using 12CO J=1-0, 2-1, 3-2, and [CI](1-0) lines), in the central 2 kpc of the type-1 luminous Seyfert galaxy NGC 7469. We will selectively probe its (relatively large) XDR with a proposed 0.3" resolution. This is the first, robust and spatially resolved measurement of the C0/CO ratio around an AGN. As an additional goal, we also try to estimate a molecular mass conversion factor from [CI](1-0) line, as this is argued to be a good mass tracer applicable to high redshifts. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy chemistry | Active galaxies | 2019-06-01T11:48:14.000 |
| 1631 | 2013.1.01099.S | 9 | First interstellar detection of the H2F+ ion and fluorine chemistry in the z=0.89 molecular absorber toward PKS1830-211 | By using new laboratory transition frequencies of the H2F+ ion, we propose a search for the ion and observations of HF and CF+ in the z=0.89 molecular absorber toward PKS 1830-211. The detection will contribute to understanding the fluorine chemistry through determined abundances of fluorine bearing molecules. So far H2F+ has not been detected in space. From chemical reaction, the ion is expected to be abundant in diffuse cloud. The molecular fractional abundances of PKS 1830-211 are found in-between those in typical Galactic diffuse and translucent clouds. The condition is suitable for H2F+ production. The rotational temperature of strongly polar molecules is equal to Tcmb=5.14 K at z=0.89, so the absorption spectrum is not too crowded (only low-energy levels are populated), and line identification is easy. HF and CF+ are known to be abundant reservoir of fluorine, and the observations are important for understanding chemical reactions in low temperature cloud. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-06-29T04:49:54.000 |
| 1632 | 2013.1.00883.S | 3 | HD141569: Pristine gas and evolved dust | The transition from proto-planetary to debris disk is a crucial stage of disk evolution and planet formation scenarios. It is a fast process, very few sources have been identified with simultaneous signatures of primordial and 2nd-generation material. Among them, HD141569 is a B9.5Ve star surrounded by several rings of micronic grains imaged at optical and NIR wavelengths (R>200 AU). The dust disk presents asymetries and tightly wound spirals which are likely resulting from planet formation. The 12CO(2-1) image from the IRAM array reveals that the CO disk is pristine and distributed in a cold (20K at 100AU), geometrically thin, but reasonnably optically thick disk, extending out to 225AU. We propose to use the unique sensitivity and resolving power of ALMA to study the gas and dust properties using B3 (continuum observations at 0.8'' resolution) and B7 (continuum, 12CO and 13CO 3-2 at 0.4'' resolution). The proposed observations will provide for the first time a quantitative measurement of the degree of evolution of the gas and dust in a transient object wich evolution status is critical with respect to the formation of gaseous planet. | Debris disks | Disks and planet formation | 2016-11-09T23:12:18.000 |
| 1633 | 2023.1.00607.S | 0 | A Census of Magnetic Fields inside Massive Dense Cores in the Central Molecular Zone | Magnetic fields have been suggested to be dynamically important in massive dense cores in the Galactic disk where high-mass stars are born. The Central Molecular Zone (CMZ) around the Galactic Center represents a different star forming environment than the Galactic disk, where the role of magnetic fields in the evolution of massive dense cores is undetermined. A previous ALMA polarization observation has revealed interesting magnetic field substructures in a small sample of massive cores in the CMZ and a potential correlation between magnetic fields and star formation states. Here, we propose to expand the experiment to a sample of 20 fields in the CMZ, quadrupling the current sample size, to uncover their polarized dust emission at 0.01 pc resolution. We will also compare with massive dense core samples in the Galactic disk to investigate how magnetic fields impact gas dynamics in the unique environment of the CMZ. This will be the first high angular resolution (<1") polarization survey toward a complete sample of CMZ massive dense cores outside of Sgr B2. | High-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1634 | 2017.1.00090.S | 33 | Do the Accretion Environments of Low Luminosity AGN Resemble that of Sgr A*? | Low luminosity active galactic nuclei (LLAGN) are powerful probes for understanding accretion and outflow in black hole systems. They represent an important link to the lowest luminosity AGN, Sagittarius A*, with 9 orders of magnitude sub-Eddington luminosity. Millimeter wavelength polarimetry has proven a unique tool for characterizing the accretion environments of Sgr A* and other LLAGN, including M87 and 3C 84. We propose ALMA Band 6 polarimetry to measure the accretion rates in three nearby LLAGN: NGC 4374 (M84), 4552, and 4579. All sources are currently undetected in linear polarization up to a frequency of 43 GHz (and 230 GHz in the case of NGC 4374). The theory of radiatively inefficient accretion flows predicts rotation measures (RMs) between 10^4 and 10^10 rad m^-2 for these sources; these RMs would depolarize past VLA measurements. ALMA polarimetry will provide sensitivity to RMs as large as 3 x 10^9 rad m^-2, testing accretion models on scales between 10 and 100,000 Schwarzschild radii. Detection of the RM will provide an accurate constraint on the accretion rate for direct comparison with X-ray estimates. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2019-04-27T18:30:22.000 |
| 1635 | 2021.1.01415.S | 0 | Tracing evolution of giant molecular clouds in the Large Magellanic Cloud: CI view | The aim of this observation is to reveal for the first time the detailed molecular gas distribution of an active star-forming region within a low-metallicity environment to understand the formation and structure of GMCs as well as the star-formation process at low metallicity. We propose mosaic observations toward five GMCs having different evolutionary stages in the LMC in [CI] with a final angular resolution of 3 arcsec by using the ACA standalone mode. CO observations in previous cycles will be used to precisely determine the density and temperature of the CO gas, and in combination with the velocity information, we can investigate the dynamics of GMCs associated and cold-dense molecular clumps prior to massive star formation. [CI] line is an important probe to reveal the distribution of molecular gas without CO emission, being a significant mass component of the cloud in low metallicity environment, affecting the system's self-gravity and providing an additional supply of gas to fuel star formation, and also a key to understand the variations of the CO-to-H2 conversion factor. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2023-09-16T09:36:29.000 |
| 1636 | 2021.1.00055.S | 76 | Comprehensive ISM view down to a ~100 pc scale for a sub-L* galaxy at z=6 by ALMA, JWST, and JVLA | We propose deep follow-up for [CII]158um and [OI]146um lines targeting two multiple images of a strongly lensed galaxy at z=6 discovered by a 100-hr ALMA Lensing Cluster Survey. Among normal star-forming galaxies at z>6, both images are the brightest lensed sources known, (H~23.7mag, [CII] flux~20mJy), but intrinsically a faint z=6 sub-L* galaxy (Mstar~10^9Msun) due to high magnifications of mu~20-160. Combined with scheduled deep JWST and JVLA observations that precisely characterize host ISM and molecular gas properties, we will assess the cold ISM properties down to a ~ 100 pc (source plane) via the two major coolant lines with underlying dust continuum, dramatically transforming our understanding of a typical z=6 galaxy by 1) studying detailed [CII] kinematics including star-forming clump motions and rotation curve of the host up to ~3 x effective radius, 2) searching for [CII] broad-wing and extended halo features, and 3) mapping every phase of the ISM: ionized, diffuse, dense neutral, and molecular. We will also observe the [CII] line of the two other multiple images to 4) refine the lens models. A comparable study is impossible, except for this uniquely lensed system. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2023-08-31T13:56:08.000 |
| 1637 | 2022.1.00435.S | 20 | A deep search for H2DO+, the missing link in the gas-phase deuteration chemistry of water | The deuterium-to-hydrogen (D/H) ratio is the main tool for investigating when, where, and how the water on Earth, in comets, and other solar system bodies formed. Therefore, a thorough understanding of the water chemistry network in star-forming regions, and the deuteration routes in particular, is key for interpreting the observed D/H ratios. A cornerstone molecule in the gas-phase water chemistry is H3O+. Observations of its deuterated isotopologue, H2DO+, and hence H2DO+/H3O+ measurements, were not possible in the pre-ALMA era because of the lack of sensitivity at high frequencies. We aim at measuring the H2DO+/H3O+ ratio around a protostar for the first time. A deep search for H2DO+, along with observations of H3O+ to constrain the spatial extent and excitation, is proposed in the high-mass star-forming region G34.26+0.15, where H3O+ emission was previously detected with a single-dish telescope. The proposed observations will pin down the importance of the low-temperature gas-phase channel in the deuteration of water and contribute to a more complete picture of the water deuteration chemistry. | High-mass star formation, Astrochemistry | ISM and star formation | 2023-10-04T16:24:11.000 |
| 1638 | 2018.1.01142.S | 120 | Exploring the molecular gas and continuum emission in giant gravitational arcs | Giant gravitational arcs offer the best opportunity to obtain sub-kpc observations of the interstellar medium in high redshift galaxies. The first targets were intrinsically infrared luminous lensed galaxies, observations that reveal the conditions of the bright end of dusty star-forming galaxies. Here we aim to study the ISM of optically bright strongly lensed galaxies. We propose observations of mid-J CO lines and continuum observations in three highly magnified (>30) low-metallicity star-forming galaxies. We will obtain gas and dust masses, as well as obscured star-formation rates, in three of the brightest and most studied optical arcs. The availability of good lensing models will allow translating our detections into source plane properties, one of the main issues associated with the observations of lensed galaxies. High magnification values are usually associated with large angular extents in the image plane. In these cases, the lower resolving power of ACA offers the optimal observation setup for the detection of the emission of the arcs. The results from this campaign will be crucial for future higher spatial resolutions observations with ALMA. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2020-09-10T16:31:15.000 |
| 1639 | 2017.1.00864.T | 53 | Constraining Jet Formation and Evolution with X-ray Binaries | Relativistic jets are launched from accreting black holes (BHs) on all scales, from stellar-mass BHs in X-ray binaries (BHXBs) to supermassive BHs in active galactic nuclei (AGN). These jets deposit significant amounts of energy into the surrounding medium, which affects star formation, galaxy evolution, and even the distribution of matter in the universe. Therefore, it is essential that we understand the physics of these accretion-fed outflows. Of the many objects that launch jets, BHXBs are ideal testbeds, as they evolve on timescales of days to months (unlike AGN that evolve over millions of years). Broad-band spectral measurements of BHXB jet emission constrain the physical conditions in the jet, which can then be coupled to the properties of the accretion flow, probing the mechanism that governs how jets are launched and quenched. The mm regime bridges a crucial gap between radio and IR frequencies in the broad-band jet spectrum. Here we target the next outbursting BHXB with ALMA, to probe the evolving mm flux. Coupled with our exceptional multi-wavelength coverage, we will constrain the dynamic broad-band spectral energy distribution in BHXBs with unparalleled accuracy. | Black holes, Transients | Stars and stellar evolution | 2018-12-08T15:22:32.000 |
| 1640 | 2017.1.00127.S | 22 | Extended Star Formation in the Brightest Unlensed Submillimeter Galaxies | Distant SMGs represent the most massive of the young galaxies rapidly building up their mass in the early universe. Their importance in terms of understanding the cosmic stellar mass build-up history is amplified if they represent the pinnacle of the "cosmic downsizing" phenomenon. We have obtained 345GHz continuum images at 0.02" resolution toward three unlensed submillimeter galaxies during cycle 3 of ALMA, with a primary science goal to investigate the detailed spatial distributions of dust in the intrinsically most luminous SMGs as a direct test of how such extreme starbursts can be fueled and sustained. We found that the morphology of dust in the central kpc is highly complex with extreme star formation properties that are comparable to (or exceeding) the Eddington limit for starbursts. We have also found that the amount of missing flux is extremely high (70-85%) compared to lower resolution SMA images, which suggests that the bulk of the star formation is in fact taking place in the extended disk. Here we propose 2.3 hours of Cycle 5 time in the C43-5 configuration to recover this missing flux and to properly image the dusty star formation activity beyond the central kpc. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-01-30T02:04:10.000 |
| 1641 | 2015.1.01471.S | 8 | Isotopic ratios in Neptune's atmosphere and the origin of CO and HCN (Resubmission of cycle 1 program) | This proposal is a resubmission of the proposal 2012.1.00624.S accepted in cycle 1 with "highest priority of being observed", but this project has not been observed. In order to avoid duplication, if this project is finally observed in cycle 2, we do not need observations during cycle 3. Isotopic measurements represent a powerful tool to diagnose the origin and evolution of planetary atmospheres. The 14N/15N ratio, in particular, shows a large range of variability throughout the Solar System. The main goals of this proposal are i) to determine the 12C/13C, 16O/18O and 14N/15N isotopic ratios in Neptune CO and HCN, in order to constrain the origin of these species in Neptune's atmosphere and to characterize isotope-related fractionation effects within the atmosphere ii) to take benefit of the large bandwidth of ALMA to simultaneously search for two additional species, CS and CH3CCH. The detection of CS would bring support to the cometary origin hypothesis for CO and/or HCN, and the measurement of CH3CCH would provide new constraints on Neptune's hydrocarbon photochemistry. This will provide novel clues to understand the origin of these molecules. | Solar system - Planetary atmospheres | Solar system | 2017-05-16T13:49:29.000 |
| 1642 | 2016.2.00172.S | 9 | Unveiling the merging substructures of a high-z cluster mapping their Sunyaev-Zel'dovich effect | ClJ0152-1357 is a massive z=0.834 non-virialized galaxy cluster characterized by a complex combination of several merging subclumps observed in many spectral bands. Thanks to its high redshift, high mass, electron temperature and density, and the merging directions apparently lying on the plane of the sky, it is a representative target to investigate the interacting substructures in a cluster in the early stages of its evolution. Our 18 GHz ATCA observations (Massardi et al. 2010), limited to the region of the most massive subclump, showed that the peak of the Sunyaev-Zel'dovich (SZ) signal is significantly displaced from the X-ray peak possibly as a consequence of major mergings of the subclumps. The combination of X-ray and SZ mapping at comparable resolutions can disentangle the temperature and the density distributions and retrieve a detailed picture of the ISM. Henceforth, we propose Band 4 (at the maximum of the negative SZ peak) ACA standalone observations to map to ~10 arcsec resolution (comparable to that of the available XMM-Newton images) the whole cluster region, to unveil the subclump properties and reconstruct models of the substructure interactions. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2019-07-08T00:00:00.000 |
| 1643 | 2019.1.01797.V | 0 | Imaging of the black hole shadow and jet base in M87 | The supermassive black hole (SMBH) at the heart of the Virgo A galaxy (M87) powers one of the most well-studied relativistic jets in the sky. Due to its high mass and close proximity, it shows the shadow cast by the black hole (BH) event horizon (EH), and promises successful imaging with unprecedented detail the jet launching mechanism. We propose four tracks of Band 6 VLBI observations with the EHT+ALMA VLBI array. The successful observations in Cycle 4 and the improvements introduced for Cycle 7 (inclusion of the KP and the NOEMA, together with a further optimized GLT) provide enhanced angular resolution and sensitivity to refine the shadow feature and enable new tests of strong-field GR. The relativistic jet and BH magnetosphere can be mapped including polarimetry, testing models of jet launch from spinning BH at the EH. The observations will be accompanied by complementary (requested) 3mm observations with the GMVA+ALMA, together with a multi-band campaign including X and gamma rays up to the TeV regime. Ultimately, we aim to connect the smallest objects predicted by Einstein's GR to galactic scale outflows that impact large scale structure in the Universe. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-12-19T23:36:13.000 |
| 1644 | 2021.1.01719.S | 40 | Unveiling the thermodynamical properties of distant, massive ICM-selected clusters | We propose ACA and ALMA observations of the Sunyaev Zeldovich (SZ) effect of two clusters, one dynamically disturbed, one relaxed, in the most massive and distant sample of SZ-selected clusters identified by the South Pole Telescope 2500 deg2 survey. We will exploit the exquisite synergies provided by ALMA, ACA, and SPT observation to probe the SZ signal of the two high-z clusters from kpc scales out to the virial radius. In combination with existing deep HST, Spitzer, XMM-Newton, and Chandra data, this will allow for building a comprehensive picture of the physical processes shaping the properties of high-redshift clusters. This will represent a key pilot study for demonstrating the feasibility of a detailed characterization of those transformational processes that have a dramatic impact on the early evolution of clusters and cluster galaxies. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2023-03-17T13:06:32.000 |
| 1645 | 2024.1.01568.S | 0 | SZ view of the thermodynamic properties of a complete sample of distant, massive ICM-selected clusters | We propose deep Band 1 observationa of the Sunyaev Zeldovich (SZ) effect for a complete SZ-selected sample of massive and distant galaxy clusters. This sample at redshift 1.4 | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 3000-01-01T00:00:00.000 |
| 1646 | 2019.A.00017.S | 10 | ALMA Observation of the New Record Breaking Quasar | We request ALMA DDT observations of a newly discovered redshift record breaking quasar, J0313-1806, at z=7.61. These observations would challenge models of the early growth of supermassive black holes (SMBHs) and place new constraints on the co-evolution between SMBH and its host at cosmic dawn. In particular, the proposed observations will deliver a 100 times better redshift measurement, and enable us to direct probe the morphology and kinematics of the quasar host galaxy. In addintion, the ALMA observations will allow us to investigate the spatial distribution of dust emission and star formation in the quasar host galaxy. These measurements will be combined with the relativistic quasar outflows detected in our infrared spectrum, and allow us to probe the mode of star formation, its connection to SMBH growth and AGN feedback. The ALMA observations will also be used to search for [CII] emitters in the vicinity of the quasar and probe whether this early quasar reside in an overdense region. Moreover, the host galaxy properties measured from ALMA observations will be crucial for planning the JWST Cycle 1 and ALMA Cycle 8 programs for further detailed studies of this exciting object. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-10-09T19:20:34.000 |
| 1647 | 2022.1.00624.T | 0 | Unveiling Short GRB Millimeter Afterglows with ALMA | Short gamma-ray bursts (SGRBs) are relativistic explosions which originate from the mergers of two compact objects (NS-NS/NS-BH). Such merging systems are also at the forefront of transient astrophysics, with the recent multi-messenger discovery of GW170817. Modeling of SGRB afterglow emission from the radio to X-ray bands provides a unique way to probe the burst basic explosion properties: the energy scales, circumburst densities, and jet opening angles. These properties not only provide critical insight into merger environments, but also serve as a vital baseline for comparison to properties inferred from future gravitational wave events. In the millimeter band, the faint and rapidly-fading afterglows of SGRBs require the sensitivity and dynamic scheduling of ALMA. Here, we propose to use ALMA TOO observations to identify and monitor, or place deep limits on the millimeter afterglows of 2 SGRBs in Cycle 9. Our proposed observations will be sensitive to SGRBs over a wide range of densities and jet opening angles. Our search will continue ALMA's newfound role in SGRB millimeter studies, and will offer hundred-fold improvement over previous millimeter searches with other facilities. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2024-11-23T04:01:15.000 |
| 1648 | 2018.1.01616.S | 41 | Resolving the dust emission in heavily obscured, hyper-luminous quasars at z ~ 1.5 | We propose a detailed ALMA study of four sources from a unique sample of 156 distant (0.5 < z < 3) heavily obscured, hyper luminous quasars (QSRs) which have sub-galactic, young radio jets. These four sources show interesting (sub)arcsec structure in 10 GHz JVLA snapshot images. The key observational goals are to spatially resolve the submm emission and look for CO line emission. Our ALMA Cycle-0 345 GHz snapshot imaging revealed all of them to be unresolved at 1" scale. This high-resolution study follows up the brightest targets with known redshifts. The setups are optimized to map the morphology of the 345 GHz (band-7) continuum on 1-2.4 kpc scales: similar to the radio jet structures and cores. The overall science goal of our multi-telescope program is to study the earliest stages in the life-cycle of luminous AGN. The key feature under investigation for this proposal is the onset of the various feedback mechanisms including, the contribution of radio jets to ISM purging and star formation quenching. In particular, we wish to study the structure and dynamics of the ISM in detail through kpc resolution imaging of the dust continuum and CO line emission. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2021-01-22T15:26:08.000 |
| 1649 | 2018.1.00704.S | 50 | Dissecting a high-mass star-forming dense clump in the center of a hub-filament system | The processes driving high-mass star formation (HMSF) are under intense debate. Central questions are related to the mass accumulation process from clump scales (>0.1 pc) to protostars and relative birth order of high vs. low-mass stars. Sensitive, high-resolution observations are crucial to disentangle between the various proposed scenarios. G22C1 is a globally collapsing massive clump at the center of a hub-filament system. A high-mass star-forming hot core (SMA1) has been detected with SMA observations. Multipolar outflows demonstrate the presence of substructures and compact star formation. On larger scales, filamentary inflows are feeding the globally collapsing massive clump G22C1 while SMA1 exhibits spectral infall signatures. In short, G22C1 is an ideal target for studying the mass accumulation in HMSF. We propose to map the entire G22C1 clump using ALMA/Band 7. Simultaneous observations of HCO+/H13CO+ (4-3), CO (3-2), SiO (8-7) and two 1.8 GHz windows will enable us to (a) observe the internal structure of SMA1 and companion low-mass cores around SMA1, (b) study the kinematics of embedded dense cores, and (c) determine the relative birth order of high and low-mass stars. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2020-08-15T20:27:47.000 |
| 1650 | 2016.1.01599.S | 15 | Nature and origin of the candidate pre-brown dwarf core OphB-11 | The origin of brown dwarfs (BDs) is an important astrophysical mystery because its solution can also shed light on how a broad range of objects, from typical stars to giant planets, are formed and gain their masses. Using the IRAM Plateau de Bure interferometer (PdBI) at 3.2 mm, we identified a good example of a pre-brown dwarf core (Oph B-11), a self-gravitating starless condensation of gas and dust in the brown-dwarf mass regime (André et al. 2012, Science). Our PdBI result tends to support models according to which BDs form in a similar manner to normal stars, from the direct collapse of a prestellar core. Because the Oph B-11 core is weak and difficult to observe from IRAM, however, its basic properties (e.g. radius, mass, density) remain uncertain and its formation mechanism is not well understood. We propose ALMA/ACA mosacing observations in Bands 6 of Oph B-11 and its immediate vicinity in order to obtain robust measurements of its size, structure, mass, and test the hypothesis that the pre-BD core was formed as a result of low-velocity shock compression. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-04-18T13:27:05.000 |
| 1651 | 2018.1.00119.S | 30 | Constraining the Interstellar Medium Properties of the Most Luminous Galaxy Known | At a redshift of 4.601 and with a luminosity of Lbol = 3.5 x 10^14 Lsun, WISE J22460526 (W2246 hereafter) is the most luminous galaxy detected to date. Cycle 2 ALMA observations of the [CII]158um emission line have revealed a strikingly uniform and highly turbulent interstellar medium (ISM) that is being blown away from the host galaxy isotropically, likely by the energetic feedback from central AGN. Recent cycle 4 observations revealed that the gas reservoir at the center of W2246 is being fed by a multiple merger process, and cycle 5 [NII] observations point to an extremely dense ionized medium. However, there are many ISM properties of this outstanding source that are still unknown. Here we propose to obtain ALMA multi-band observations of W2246 in the [CI]607um, [CI]370um, [OI]145um, [OIII]88um and [OI]63um emission lines, at an angular resolution similar to that of our [CII] and [NII] data, ~0.3". The goal of this project is to use this suite of far-infrared lines to characterize the properties of the gas in a galaxy that represents the ultimate laboratory for studying and model the ISM physics and kinematics under strong feedback at high redshift. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2022-10-14T23:52:53.000 |
| 1652 | 2013.1.00099.S | 25 | Dense Gas Thermometry of Starburst Galaxies | A characterization of the physical properties of the dense gas within the interstellar medium of starburst galaxies is critical to our understanding of their evolution. Many of the molecular tracers used to characterize the dense gas in star-forming galaxies suffer from a coupled degenerate sensitivity to the kinetic temperature and volume density. A molecular tracer which can decouple individual physical conditions is required. Results from a survey of a sample of active star-forming galaxies has shown that Formaldehyde (H2CO) is a reliable and accurate density probe for extragalactic environments where the kinetic temperature is known. Ammonia (NH3) is a traditional probe of the kinetic temperature in dense gas environments, but its utility requires an assumption of cospatiality between dense gas tracers is required. Using the unique sensitivities to kinetic temperature afforded by the excitation characteristics of several transitions of H2CO, we propose to continue our characterization of the dense gas in galaxies exhibiting starbursts by imaging the gas kinetic temperature in a representative pilot sample of three starburst galaxies: Arp220, NGC253, and NGC4945. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2016-01-05T00:00:00.000 |
| 1653 | 2012.1.00469.S | 3 | Probing the effect of ionization on the circumstellar structure of the massive embedded star AFGL 4176 | Using the ALMA Cycle 1 extended configuration in band 6, we prepose to observe AFGL4176, a highly luminous embedded massive star for which we have already mid-infrared interferometric and ATCA 20-24GHz observations to hand, to determine the impact ionizing radiation can have on the surrounding geometry, kinematics and physical properties of the accreting material. Our proposed observations centered at ~240 and 255 GHz will trace molecular and ionized gas, as well as dust, in the same observation, using observations of CH3CN 13(k)-12(k), H29alpha and dust continuum respectively. These observations will also allow us for the first time to combine and model interferometric observations from two state-of-the-art telescopes in different wavelength regimes: ALMA and VLT. By combining and modelling the results of our proposed ALMA observations with our MIDI mid-IR interferometric data, we will trace the geometry continuously on scales spanning hundreds to tens of thousands of AU. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2015-09-12T12:41:27.000 |
| 1654 | 2023.1.01358.S | 0 | Deciphering the large- and small-scale B-field morphology in a massive star-forming clump | Determining the morphology of the magnetic field in high-mass star-forming regions is crucial for understanding their role and importance in the formation of massive stars. G31.41+0.31 is a well-known example of an OB-cluster forming clump with an hourglass magnetic field in the inner 0.1 pc, as resolved by high-resolution (0.2-arcsecond) 0.89-1.3 mm dust polarization maps. However, a recent 2-arcsecond resolution 7 mm polarization map revealed that the large-scale (0.4 pc) magnetic field is rather uniform and perpendicular to the axis of the small-scale hourglass field. We hypothesize that this discrepancy is caused by the misinterpretation of the 0.89-1.3 mm map due to missing short-spacing data or that the 0.89-1.3 mm and 7 mm maps trace different polarization mechanisms. To investigate this discrepancy, we propose a 0.2-arcsecond resolution, optically thin, full polarization observation at 2.1 mm (band 4) that could recover the cloud up to 20" (~0.4 pc). We aim to discern how the large-scale uniform B-field is connected to the small-scaled hourglass field and clear up the polarization mechanism(s) traced in previous studies. | High-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1655 | 2024.1.01483.S | 0 | Unlocking the Door to Gas Dynamics of ~1-10pc scale Star Clusters at Cosmic Dawn | Recent JWST studies have identified strongly lensed star clusters (SCs) even at z=6-10, offering us new hope of directly studying such compact systems and their local environments at cosmological distances. We propose [OIII]88um and [CII]158um observations of a remarkably bright (muv=24.4mag), but intrinsically faint (~0.02L*) strongly lensed galaxy newly discovered at z=8.304 in the latest JWST observations. In the 5" long lensed arc, the NIRCam maps out diffuse ISM gas as well as numerous clumps that are the most distant spec-z confirmed, gravitationally-bound SCs known, with the intrinsic sizes less than 10 pc scales, the size of local SCs. The main goal of this program is to obtain total fluxes of the [CII] and [OIII] lines from individual bright SCs to the entire galaxy by combining ALMA compact and extended configurations. Beyond the first FIR views of the earliest-stage of assembly of the Milky Way-type galaxy, this is a critical step to design the next deep high-resolution ALMA and JWST follow-up, which provides the key insights into the dynamical mass, ionization state, and feedback effects down to the individual SCs less than 10-pc scales at cosmic dawn. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1656 | 2017.1.01618.S | 102 | Do there exist mini-SMGs at cosmic noon? | We propose band-6 observations of six low-mass (Ms~10^9Msun) but red (UV slope >= -1.2) star-forming galaxies primarily selected from our large spectroscopic sample of z = 2.2 Lyman alpha emitters. SED fitting to their rest-frame UV to NIR photometry gives as high IRX=L(IR)/L(UV)~10 as of submm galaxies (SMGs), placing them well above the average IRX-Ms relation. In the literature, only one such miniature SMGs has been likely identified at cosmic noon because of faint dust emission. In this proposal, we will measure L(IR) for the six objects from dust continuum and derive dust-obscured star formation rates, SFR(IR), and dust masses, Md. High SFR(IR) and Md, if obtained as expected, will demonstrate that even low-mass galaxies, although not majority, experience dusty starburst, urging dust formation models to find a way to very efficient dust production in low-mass galaxies, which appears to be a more serious problem than the dust budget crisis of SMGs. | Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies | Galaxy evolution | 2019-04-16T16:02:25.000 |
| 1657 | 2024.1.01696.S | 0 | The initial gas motions: Outflow and shock towards extremely young high-mass clumps | How the initial gas motions (e.g., outflow, infall, shock) link to the high-mass star formation (HMSF) remains unclear. Systematic researches on outflows and shocks in initial environments of HMSF (e.g., infrared dark clouds) are limited due to the requirement of high-sensitivity telescopes and suitable sources. Our previous ALMA observation revealed a highly suitable sample of 16 extremely cold, dense clumps with SiO 2-1 detection. More than 1/3 of the observed shock events in this sample originate from outflows, characterized by SiO linewidths > 20km/s and blue- or red-shifted line wings. However, insufficient observations from our previous ACA and TP data hindering quantitative analysis of the outflows. Therefore, we propose new ACA and TP observations to recover extended structures of existing high-sensitivity 12m data. We expect to (1)investigate outflows (e.g., mass entrainment rate) from extremely young high-mass clumps, (2)identify the starless candidates (cores with SiO FWHM < 20km/s and no associated outflow), (3)understand the gas fed pattern at core scale by camparing infall and outflow distributions. The proposed observation will be part of a PhD thesis. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1658 | 2022.1.01401.S | 20 | A new ALMA window on Cosmic Dawn: pilot at z~10 | Searches in CO or C+ for ultra-high-redshift galaxy candidates have consistently failed, possibly due to underabunbdance of C at the earliest epochs, while [OIII] has shown promise. The pioneering and unexpected detection of water in absorption against the CMB in the z=6.34 galaxy HFLS3 strongly suggests that the CMB will be found to pump other transitions depending on redshift. We have therfore conducted a systematic search in the ALMA archive for other species in absorption in ultra-high-redshift galaxies, and detected a P Cygni line in the galaxy GS-z10-1, which we identify as either the OH+ 909 GHz or 972 GHz transition. The positive flux significant at 5.4 sigma and the absorption at -3.0 sigma, and the redshift is consistent with the photometric estimate of z_phot = 9.9 +/- 0.5. Here we request urgent follow-up redshift confirmation through the bright [OIII] 88micron line, which is redshifted to ALMA Band 7. This will be a highly effective proof of concept for redshift determination in ultra-high-redshift galaxies using absorption lines in the low frequency end of Band 3 and in future in Band 2, and will open up the >3mm windows for exploring Cosmic Dawn. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-01-11T12:16:00.000 |
| 1659 | 2023.1.00882.S | 0 | Physics of the cold circumgalactic medium in the Spiderweb: new high-z science with ALMA Band-1 | ALMA Band-1 will open exciting new science areas, one of which is to study how cold molecular gas on large scales drives the evolution of distant galaxies. ALMA's ultra-compact configurations are unique for imaging low-surface-brightness emission from molecular gas in the circumgalactic medium (CGM). We will use Band-1 to image CO(1-0) from widespread, cold molecular gas across the halo of the massive Spiderweb Galaxy (z=2). For the first time, we will study the physical processes of molecular gas locally within the CGM (excitation, carbon abundance, star formation, and AGN feedback), by comparing the CO(1-0) to CO(4-3) and [CI] (ALMA Band-4), diffuse starlight (HST), and the radio source (VLA). In addition, utilizing the large field-of-view of Band-1, we will characterize large molecular gas reservoirs in 19 CO-detected protocluster galaxies in the Spiderweb field, some of which already revealed molecular disks or tidal debris on tens of kpc scales. Our deep CO(1-0) imaging of spectacular molecular reservoirs around the Spiderweb and neighboring galaxies will highlight new Band-1 science, and showcase ALMA's role in studying the critical role of the cold CGM in galaxy evolution. | Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1660 | 2018.A.00026.S | 46 | Mapping CO Emission in eta Carinae near Periastron Passage with ALMA | Numerous molecules are formed in eta Car's nebula despite the intense ionizing radiation field from the hot binary at the center. The shielded features may be a result of a stellar merger following an eruption by a single massive star. The present-day binary from the hypothetical initial triple-star has an eccentric 5.54-year orbit, currently at phase 0.82; periastron occurs in 12 months. We propose to observe CO (2-1) and (1-0) and H30-alpha at 0.2"-2.0" resolution in phase < 0.9 (a ~6 month window), just prior to a sharp drop in X-ray/UV field intensity as the hot companion dives into the primary's dense wind. This will allow us to physically characterize the shielding structures associated with at least 7 known kinematic components during the ionization high state, complemented by our single-dish ground-, airborne, and space-based observations, and upcoming HST, VLTI, and Chandra observations. The DDT path is motivated by our extended team's new publication describing the radiation field's cyclic evolution and nebula response times, and will reward us with insight into eta Car's role in a broader paradigm for LBV activity related to stellar mergers. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2019-11-06T21:28:16.000 |
| 1661 | 2012.1.00240.S | 6 | Mapping Star Formation and Gas Dynamics in Luminous Quasar Host Galaxies at z~6 | Understanding the growth of the first supermassive black holes (SMBHs) and their host galaxies is one of the primary goals of modern galaxy evolution studies. We propose to make spatially resolved observations of the [C II] 158 micron fine structure line and dust continuum emission in three z~6 quasars that are detected in our Cycle 0 project, to trace the distribution of star formation and measure the kinematics of the host galaxy. Strong FIR dust continuum, molecular CO line emission, and massive star formation have been discovered in about 30% of the quasars known at z~6. These FIR luminous quasars at z~6 provide the brightest sample to study galaxy formation and SMBH-galaxy coevolution within 1 Gyr of the Big Bang. Deep imaging of the [C II] line emission from the brightest source, SDSS J1148+5251 at z=6.42, reveals a peak star formation rate surface density of 1000 Msun/yr over the central few kpc region, together with strong gas outflow driven by AGN feedback. We have an ALMA Cycle 0 project to search for [C II] line emission from a sample of five FIR-luminous quasars at z~6. We have data in hand for three of them and all are strongly detected. The line velocity maps of two of them show tantalizing hints of velocity gradients which may suggest emission from a rotating starburst disk; the third object shows a broader [C II] line compare to previous CO observations. High S/N and resolution observations are required to confirm and fully understand these intriguing trends. The excellent capability of ALMA in Cycle 1 now open a unique opportunity to resolve the [C II] line, dust continuum emission, and star forming activity, on kpc scale (0.2" resolution) from these most distant starburst quasar host galaxies. We here propose to extend the [CII]/dust continuum imaging to all the three new Cycle 0 detections at z~6 with ALMA in C32-6 to measure the star formation rate surface density and constrain the general bulge building process in these earliest quasar host galaxies. Moreover, the resolved velocity field of the [C II] line emission will trace the kinetic properties of the atomic gas in the starburst nuclear region, measure the circular velocity and dynamical mass of the stellar bulge, and address if the gas outflows found in J1148+5251 are common in all these young quasar host galaxies at the earliest epoch. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2016-09-28T17:44:10.000 |
| 1662 | 2023.1.00040.S | 0 | Angular momentum in hub-filament systems: Deciphering signatures of rotation and global collapse. | High-angular resolution observations of high-mass disk and toroid candidates suggest that their angular momentum is up to 2 orders of magnitude higher than that of low-mass disks. IRAM 30-m N2H+ observations of one of these toroids, G31.41+0.31, have revealed that the kinematics at large cloud scales (10^5 au) and small toroid scales (a few 10^3 au) could be tightly connected, and that the specific angular momentum distribution for high-mass YSOs might be fitted with a single power-law from cloud to circumstellar scales. We propose to map with ALMA at 3.7" resolution and with a mosaic of 75 pointings the entire G31.41+0.31 cloud in N2H+(1-0) at 93.174 GHz. The goal is twofold: i) to map the velocity field of all the IR-dark filaments to search for velocity gradients along the filaments that could confirm that matter is flowing toward the central hub/core, and ii) to trace the kinematics of the gas at intermediate scales, filling the gap between 10^5 au and a few ~1000 au, to estimate the radial distribution of specific angular momentum over the cloud and determine whether this quantity decreases with radius in a manner similar to the trend found for low-mass star-forming regions. | High-mass star formation | ISM and star formation | 2025-11-18T15:17:09.000 |
| 1663 | 2017.1.01355.L | 1619 | ALMA-IMF: ALMA transforms our view of the origin of stellar masses | Studying massive protoclusters is an absolute requirement for investigating the origin of the IMF in the typical, yet extreme environments where massive stars are born. Recent ALMA imaging of a young massive protocluster revealed the first definitive case of a core mass function (CMF) whose shape is different from the IMF. In contrast, the CMF shape in more evolved but still embedded massive clusters more closely resembles the IMF. This raises the intriguing possibility of CMF evolution with time. We aim to determine when and by which physical processes the CMF of massive protoclusters is reconciled with the canonical IMF. We propose to investigate the CMF evolution of massive protoclusters with the 15 most massive pc^2 clouds at d < 6 kpc. We will focus on 1) investigating the distribution of 0.5-200 Msun cores at 1~mm and 3~mm at the 2000~AU core size; 2) characterizing the core mass evolution through gas inflows toward individual cores and gas outflows driven by protostars; and 3) compare massive protocluster CMFs to the IMF and determine which variables (such as inflows, outflows, or forming filaments) might be correlated with CMF evolution toward the IMF shape. | High-mass star formation, Low-mass star formation | ISM and star formation | 2019-04-25T20:23:51.000 |
| 1664 | 2017.1.00983.S | 163 | Quantifying the Feedback Potential of Young Massive Protoclusters | In a series of radio and infrared surveys, we have identified a sample of 20 massive protoclusters existing in a specific evolutionary state in which outflows dominate their infrared appearance. Our SMA millimeter data at 3" resolution reveal high velocity CO emission (up to +-80 km/s) with complex morphology indicative of multiple actively-accreting protostars. We propose to test the theoretical idea that the combined outflow feedback is enough to maintain turbulence but not enough to disrupt the parental gas reservoir, thereby allowing star formation to proceed at a regulated rate. We will image 10 protoclusters on scales of 0.8"-20" for which we also have SOFIA mid-IR imaging observations. Using a set of outflow and hot core tracers, we will resolve individual outflows, identify their driving sources, and compute their momentum and energies. The combination of SOFIA and ALMA continuum imaging will enable measurements of the individual protostellar luminosities thereby allowing an accurate estimate of the contribution of radiative feedback. We will compare these results with the gravitational energy of the gas and the dynamical mass of the cluster. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2020-02-26T00:00:00.000 |
| 1665 | 2022.1.01384.S | 20 | Probing the origins of [CII] emission in the Epoch of Reionization | We propose band 5 observations to measure [NII]205um emission lines from three [CII] luminous galaxies in the epoch of reionization (at z=6.5-7.7). These galaxies were recently spectroscopically confirmed by their luminous [CII]158um emission lines as a part of an ALMA observing campaign. While the recent [CII]158um line observation provided a large number of detections, the detailed origins of [CII] lines are still elusive. Despite the uncertainty, [CII]158um emission lines are used as tracers of several galaxy properties (e.g., star formation rates and neutral gas mass). To accurately understand the origins of the [CII] emission line and to understand the conditions of ionized and photodissociation gas, multiple emission line observations are needed. By the proposed observations of [NII] 205um we will achieve the following: (1) investigate whether PDR or HII regions are the dominant source of [CII] line, (2) model ionized and photodissociation gas by combining existing and incoming observations. These observation provide a showcase of emission line from ionized gas in the EoR, in conjunction with the scheduled Cycle-1 JWST observations. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2024-01-16T19:28:57.000 |
| 1666 | 2023.1.01468.S | 0 | Mass-loss and the evolution of the most massive stars in the Galaxy | Massive stars impact on fields as diverse as galactic evolution, core-collapse SNe and the birth of black holes and neutron stars; the latter particularly relevant with the dawn of gravitational wave astronomy. However, we lack a complete understanding of their evolution: for a star of given mass we cannot yet predict how it will die, nor the nature of the resulting relativistic remnant. This is the result of the lack of a theoretical framework for quantifying mass-loss, with evolutionary codes relying on empirical constraints which, at worst, are uncertain at the order of magnitude level. Consequently, we propose to observe the Arches cluster, which contains very large numbers of very massive (>60 Msun) stars for which we may obtain mass-loss rates via simultaneous quantitative analysis of extant VLT spectroscopy, HST photometry and critically, ALMA mm-continuum observations. This will provide a unique insight into the dependance of mass-loss on properties such as stellar mass and luminosity for the most massive stars that nature permits; essential input physics for stellar evolutionary models as well as spectral and population synthesis codes. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2025-07-22T11:11:32.000 |
| 1667 | 2015.1.00408.S | 14 | The G16.59-0.051 Disk+Jet System: A Bridge between Low- and High-Mass Star Formation | Comparing the few disk+jet systems detected around B-type YSOs with those in low-mass YSOs is fundamental to test if the process of mass accretion/ejection does simply scale with the YSO mass and should help judging about the existence of such ordered structures in the extreme environmental conditions of an O-type star. We have discovered a clear example of a B-type YSO surrounded by a disk+jet system in the HMSFR G16.59-0.051. A small (size~0.3") rotating structure (the "disk") is traced both by the 3-D velocities of the 6.7 GHz methanol masers and the LSR velocities of the NH3(2,2) line emission. Our recent JVLA A-array observations (at 6, 2 and 1.3 cm) have revealed an extended (3"-4") 6 cm radio jet (emerging from the disk and directed close to the maser rotation axis), and compact 1.3~cm, free-free emission placed near the centre of the maser distribution. The stellar mass implied by the observed luminosity (13 M_sun) agrees well with the equilibrium mass (12 M_sun) of the maser disk. We propose ALMA observations of typical "disk" and "molecular outflow" tracers, employing the C36-5 configuration of the array and Band 6. | High-mass star formation | ISM and star formation | 2018-02-16T10:11:22.000 |
| 1668 | 2021.1.00637.S | 19 | A [CII] census in two giant Lyman-alpha blobs at z=3 | Extended Lyman-alpha nebulae (so called Lyman-alpha blobs, LABs) provides a benchmark of the presence of plentiful hydrogen on circumgalactic medium (CGM) scales and provides clues to understanding galaxy formation and evolution. One of the most spectacular LABs known to date is LAB1 in the SSA22 proto-cluster at z = 3.1. Recent ALMA observations revealed that the [CII] emission is widely distributed in a central 100 kpc region of LAB1, also showing multiple major-mergers. To expand our understanding from one case study to the more general picture, we here propose to observe [CII]158um emission and dust continuum for two additional LABs in the proto-cluster, LAB2 and LAB8. In conjunction with MUSE Lyman-alpha data, we will uncover the ISM in and around galaxies associated with these two spectacular LABs. Our immediate goals include: (i) to determine the power source of the Lyman-alpha emission; (ii) to uncover the interplay between galaxies and surrounding gas; and (iii) to trace galaxy assembly in LABs. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-09-23T14:41:23.000 |
| 1669 | 2021.1.01628.S | 93 | 85 birds -- 1 stone: The most efficient line survey of SMGs in Bands 3 through 8 | The Herschel space observatory mapped more than 1000 sqr. deg. and detected more than half a million sources. Recent redshift searches are enabling full spectroscopic follow up; however, exploiting this with ALMA is challenging, as the large overheads favour deep studies of individual sources. Here, we propose an alternative to targeted single-spectral line surveys. Instead, using ALMA as efficiently as possible, to observe 16 sources in CO, [CI], and H2O, as well as absorption and fine-structure lines together with the dust continuum, each of which are sensitive to different phases of the ISM and galactic phenomena, such as turbulence, obscured AGN, molecular gas mass, gas temperature and star-formation rate. We can do this within 6.5 hours by observing sources within 10 degrees on the sky in quick snapshots that do not require re-calibration, targeting 85 spectral lines in within a single tuning set-up in Bands 3, 4, 5, 6, 7, and 8. We will facilitate future observations by making this method public and widely available within the ALMA (and wider interferometric) community. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2022-12-14T20:07:48.000 |
| 1670 | 2022.1.00450.S | 341 | A systematic Characterization of the Outflows at Ophiuchus Molecular Cloud | While essentially all nearby ($<$ 200 pc) star-forming regions (Ophiuchus, Lupus, Chamaeleon, and Taurus) have already been surveyed by ALMA in the continuum, a systematic identification and characterization of their molecular outflows is yet to be done. The Ophiuchus molecular cloud is particularly well suitable for such an study as it contains a large number of embedded sources. Using ALMA archival data available for the entire population of young stellar objects in the cloud, we have identified a total of 20 new molecular outflows associated to Class I to Flat spectrum sources. Here we propose a Band-6 project to characterize the morphology and dynamical parameters of the new identified outflows. This will result in the first systematic demographic study of outflows at high angular resolution in a nearby molecular cloud and associated to Class I to Flat spectrum sources, which will help to put into context the many studies of individual outflows already present in the literature. | Outflows, jets and ionized winds | ISM and star formation | 2024-08-31T18:51:24.000 |
| 1671 | 2024.1.01577.S | 0 | The Definitive View of M83's Center: Completing A Deep Parsec-Scale Survey of the Nearest Nuclei | We propose to make 0.13" (3 pc) Band 3 and 7 observations of M83's central 450 pc, substantially increasing the sensitivity and spatial resolution of prior ALMA observations. The proposed observations will complete a uniform-resolution and sensitivity archival sample of the nuclei of the 4 nearest massive spiral galaxies accessible to ALMA which can be compared with our own Milky Way center. M83 is a key target for this sample as its face-on orientation allows the radial distribution of gas and star formation to be directly probed, testing models for the structure and evolution of galaxy nuclei. In addition to the continuum we will observe multiple lines of key dense gas tracers (HCN, HCO+, CS, HC3N) as well as the H40 alpha recombination line. With these data we will make accurate measurements of the clustered star formation rate, gas kinematics, and gas density. Our observations of M83, when combined with data for other galaxies in the ALMA archive, will be a major step toward building a sample capable of probing the secular processes driving the cycle of activity in galaxy centers. | Starbursts, star formation, Galactic centres/nuclei | Active galaxies | 3000-01-01T00:00:00.000 |
| 1672 | 2015.1.00341.S | 51 | Revealing Magnetic Field Structures: IM-mass Cores in OMC-3 | Understanding the magnetic field on size scales smaller than a core (<0.05 pc) is crucial to see how the magnetic field is responsible for setting initial conditions of star-formation. We propose polarization and molecular line observations toward candidates of intermediate-mass prestellar and protostellar cores in OMC-3, where is the nearest ideal laboratory for studying the magnetically regulated core-collapse process. Proposed polarization observations will spatially resolve the polarization distribution and we aim to measure the polarization degree down to 200 AU scale for all the targets, and down to 12 AU for the brightest and youngest protostellar source found in OMC-3. Proposed line observations will directly image core internal structures such as pseudo disk, circumstellar disk, and root of the outflow, and reveal their kinematic structures with the same angular resolution obtained for polarization images. The obtained results will be compared and iterated with theoretical models (MHD simulations) optimized specifically for our targets, and finally study how the magnetic field changes with respect to the evolutionary stages of cores. | Intermediate-mass star formation | ISM and star formation | 2018-11-20T00:00:00.000 |
| 1673 | 2021.1.01503.S | 0 | Massive, rapidly quenched galaxies 2 Gyr after the Big Bang. What happened to their ISM? | Reconstructing a detailed view of all the possible quenching pathways of massive galaxies is a daunting task. While their stellar component provides a wealth of information, little is yet known of their interstellar medium besides it being insufficient to sustain star formation. Recent efforts to probe the ISM of quiescent galaxies extend only to z=2 and have produced mixed results. Here we propose to investigate the ISM content of a homogeneously-selected sample of 10 spectroscopically confirmed quiescent galaxies at 2.3 < z < 3.2 (the largest in this range). These rapidly quenched, bulge-dominated, compact galaxies are representative of some of the earliest quenching events known to have occurred in the Universe. We request a total of 25.8h of ALMA continuum observations at 1.1mm to obtain a direct constraint on their dust emission, a critical piece of information still lacking at these redshifts. These observations will systematically extend gas fraction evolution studies up to z~3 and down to 5% on individual sources. They will also clarify whether dust obscured star formation has anything to do with post-starburst spectra dominating massive quiescent galaxies at these epochs. | Galaxy structure & evolution | Galaxy evolution | 2025-03-07T16:45:22.000 |
| 1674 | 2011.0.00525.S | 0 | Imaging the Most Luminous Galaxy within z=0.01 | We propose high resolution imaging of molecular gas in the most luminous galaxy within z=0.01. Our main targets in the merger NGC 3256 (D=40 Mpc, Lbol=4e11 Lsun) are the double nuclei with a 1 kpc (5") separation and the >1000 km/s-wide high-velocity gas in the central region, which we have previously found and attributed to a massive molecular outflow. We will assess the dynamical and physical properties of the molecular gas in the merger to uncover the interplay between molecular gas and the high luminosity starburst, a key process in the merger-induced galaxy evolution. Our cycle 0 observations of this nearby luminous infrared galaxy (LIRG) will also serve as a pilot study for full-ALMA observations of more distant LIRGs (z ~< 0.1) since the linear resolution and mass sensitivity will be comparable. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2013-11-08T09:59:00.000 |
| 1675 | 2018.1.00765.S | 157 | The parsec scale view of the starburst ISM through molecular diagnostics | Extreme activities in starburst galaxies have a direct impact in their molecular interstellar medium (ISM). Parsec-scale resolution observations allow for the study of the ISM in starburst galaxies down to young stellar cluster scales. Thanks to its proximity and brightness, the starburst galaxy NGC 253 allows for the most detailed studies of the ISM in an starburst environment using (sub-)millimeter molecular and recombination lines. These lines are an effective probe due to their large penetration depth. Using measurements of a variety of molecular diagnostic and recombination lines, we will study the physical conditions, effects of UV-photons and shocks, excitation conditions, and star formation rates on young star cluster spatial scales. We will perform a spectral scan in Bands 6 & 7 with 0.2 resolution in the central 15 of NGC 253 to cover all transitions of interest. Short spacing information will be provided by the our ongoing project. Our spectral scan will efficiently reveal the highly excited physical conditions, effects of feedback, the evolutionary stages within the central molecular zone in the nearest starburst galaxy NGC 253. | Galaxy chemistry, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2021-02-12T09:49:45.000 |
| 1676 | 2013.1.00812.S | 10 | Hiding in the Shadow of Giants: Low mass cores in massive (proto)clusters | Most stars form in clusters, yet basic aspects of how this occurs remain unknown, including the relative birth order of high and low mass stars. In clump-scale "competitive accretion"-type models, massive stars and their surrounding cluster of lower mass stars form simultaneously. Thus a key, testable prediction of these models is that centrally condensed low-mass cores should exist within the accretion reservoir of a forming massive star. Using the unprecedented sensitivity and dynamic range of ALMA, we propose to test these models by searching for the 1.0 mm continuum emission from the low-mass core population associated with two young massive (proto)clusters that show strong evidence for recent shocks, active outflows, and hence ongoing accretion (both GLIMPSE Extended Green Objects, EGOs). By imaging the full extent of the associated (sub)mm clumps (~0.8 pc diameter), we will characterize the entire low-mass core population of our target clusters, down to 0.1 Msun. To measure the kinematics of these cores, we also target the N2H+(3-2) line. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-08-07T11:05:20.000 |
| 1677 | 2022.1.00788.S | 6 | A zoom-in view on the archetypal disk at z > 4. Is it really a disk? | High-resolution dynamical studies of star-forming galaxies up to z ~ 4 have been crucial to gaining insights into the processes driving the growth of galaxies across cosmic time. Understanding the dynamical properties of typical galaxies at z > 4 is the next step to pushing our understanding into the early phases of structure assembly. We propose to gather 1 kpc-resolution [CII] line data of a main-sequence galaxy at z = 5.5, HZ4. Generally considered as the archetypal high-z rotating disk, the application of a novel kinematic classification method on ALMA archive data of HZ4 shows that it is, instead, a merger. Thanks to the requested data, we will solve this puzzle and characterize its dynamical state robustly with morphological and kinematic analysis. This will allow us to gain insight into the assembly of early galaxies. The combination of multi-wavelength observations on matched spatial scales will provide the most detailed view of 1 kpc-scales of a typical galaxy at z = 5.5, investigating the dark matter content and turbulent structure of its interstellar medium. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2024-10-25T20:45:16.000 |
| 1678 | 2018.1.00248.S | 10 | Zooming into a Swift/BAT-selected buried AGN of NGC 7172 with a candidate dispersion-dominated thick gaseous disk | We propose to conduct 0.1" or 16-pc resolution ALMA Band-6 observations of CO(2-1) at the nucleus of NGC 7172, hosting a "New-type" AGN selected by the Swift/BAT all sky survey. Subsequent X-ray spectroscopy suggests the fractions of scattered soft X-rays w.r.t.the direct emission is only < 0.2%, an order of magnitude smaller than classical type-2 Seyferts (1 - 3%). Furthermore, our recent ~100-pc resolution ALMA observations of CO(2-1) reveal a drastic increase of the velocity dispersion to rotation velocity ratio, sigma/Vrot, a key indicator of the disk thickness, at r<100 pc of NGC 7172. These facts make NGC 7172 a promising target hosting a SMBH embedded by a geometrically thick torus with a very small opening angle. Our primary goal is to test if the CO(2-1) gas disk in NGC 7172 exhibits a high sigma/Vrot ratio beyond unity, which supports the presence of geometrically thick cold molecular material in the central ~10 pc region of a new-type AGN. We will also search for any signature of molecular outflows at r<100pc, to compare with the putative OH outflow by Herschel and ~kpc scale outflow uncovered in the previous ALMA data. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2020-12-18T19:23:14.000 |
| 1679 | 2021.1.01006.S | 32 | Revealing the cold ISM properties at 150pc scales in a strongly lensed UV-bright star-forming galaxy at Cosmic Noon | Strong gravitational lensing has become a prime tool for resolving the star-forming interstellar medium of high redshift galaxies down to sub-kpc scales. While the first ALMA studies focused on intrinsically luminous lensed targets, recent work has pioneered the study of star formation and molecular gas in fainter, lower mass and lower metallicity galaxies, which are more representative of the global population at z~2. Here we propose high resolution imaging of CO and dust continuum emission of a strongly lensed, but otherwise typical, main sequence galaxy at z=2.4. Recent HST and SINFONI observations reveal ionized gas outflows arising from an active nucleus, making this target a unique opportunity for investigating the effect of an AGN on the molecular gas. The proposed observations will allow us to measure the resolved star formation law, the sizes and the relative distributions of gas and dust. The results of this program will help us build a complete picture of a typical star-forming galaxy at cosmic noon by connecting stars, gas and dust at 150pc scales. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2023-09-05T22:20:22.000 |
| 1680 | 2012.1.00538.S | 1 | The physical structure of a massive and dense cold core | Despite significant efforts to understand the formation of massive, clustered stars, we lack a clear understanding about its nature. Two very different scenarios have been proposed for this process: Core Accretion and Competitive Accretion. The former requires a centrally concentrated monotonicaly collapsing cloud, while the latter, a distribution of smaller cores spatially distributed within the cloud. Here we propose to observe G305.136+0.068, a massive and dense cold core (T~15 K), which by being isolated constitutes an ideal case for observationally constraining these scenarios. Thanks to the new capabilities offered by ALMA, we can study in detail the mass distribution and kinematics of the core through the mapping of different molecular lines: N2H+ will trace the physical and kinematic conditions of the densest part of the core, while HCO+ and CS will allow us to trace the outer and less dense regions. For the first time, we will achieve the necesary spatial resolution to distinguish between Core and Competitive Accretion and therefore, advance in our understanding of massive star formation theory. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2015-06-19T13:23:08.000 |
| 1681 | 2021.1.01311.S | 8 | Confirming a z~6.9 Sub-mm Galaxy in COSMOS Hosting a Radio-Loud AGN | We propose Band 6 observations to confirm the redshift of a dusty, massive z~6.9 galaxy identified over the COSMOS field that shows multiple signatures of hosting a radio-loud AGN. We will employ a [CII]158mum scanning strategy has proven to be highly successful at spectroscopically detecting massive reionization-era galaxies with ALMA. Upon confirmation, this source will be not only the highest-redshift radio-loud galaxy yet discovered, but also the highest-redshift unlensed sub-mm galaxy (L_IR ~ 3e13 L_sol). Because this galaxy was selected over a relatively small field, confirming its high-redshift nature would suggest that radio-loud (non-quasar) AGN may be a significant accretion mode for supermassive black hole formation, helping understand how these objects formed so rapidly in the early Universe. Our observations will simultaneously provide morphological and kinematic maps of the gas and dust within this highly obscured system, constraints on its small-scale environment via serendipitous [CII] detections from ~50x lower-mass neighboring sources, and improved insight into contribution of dusty galaxies to the cosmic star formation rate budget at z>6. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2023-01-07T22:16:14.000 |
| 1682 | 2024.1.00534.L | 0 | ALMA Chemical Evolution (ACE) Survey: A Full Census of the Cycle of Gas, Metals, and Dust at Cosmic Noon | The cycle of baryons through galaxies is at the core of galaxy evolution. To understand the baryon cycle, the content and conditions within the multi-phase ISM must be constrained. We propose the ALMA Chemical Evolution (ACE) survey to study the baryon cycle of the important, yet unexplored, population of sub-solar metallicity galaxies at Cosmic Noon (z~1-3). ACE will observe CO and dust continuum of 25 galaxies at z~2 with key metallicity measurements down to 35% solar. It will not only double the size of the existing CO+metallicity samples of main-sequence galaxies at z>1, but also extend them to an order of magnitude lower mass and metallicity. ACE will study the fundamental role of molecular gas reservoirs in shaping the mass-metallicity relation and will link metals in gas-phase to those locked up in dust grains to constrain the buildup of dust, for the first time in a range of galaxies at Cosmic Noon. This survey is timely to provide unprecedented observational constraints for the numerous recent theoretical advances, marking a transformative leap forward in understanding the fundamentals of galaxy evolution and baryon cycle at the peak of cosmic star formation activity. | Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1683 | 2018.1.01218.S | 34 | Disk substructures in TW Hya: Optically Thick or Large Grains? | Our understanding of protoplanetary disks is rapidly changing as complex substructures are now routinely revealed by ALMA. However, the role of disk substructures in the dust evolution process is not well understood. Here we request Band 3 observations with 0.05arcsec of angular resolution toward the closest protoplanetary disk, TW Hya. Previous ALMA observations of TW Hya show multiple rings that are consistent with either optically thick emission, or optically thin emission from cm-sized dust grains. We plan to resolve the disk substructure at the longest wavelength (hence optically thinner emission) probed by ALMA. Our proposed observations, combined with previous data between 0.87 and 7 mm, will allow us to map the spectral index in the disk and constrain the dust density and size distribution in the rings. This will inform us whether disk substructures are trapping large dust grains and enabling dust growth beyond cm sizes. Confirming this scenario would have a critical impact on our theories of planetary formation. | Disks around low-mass stars | Disks and planet formation | 2020-11-27T15:33:53.000 |
| 1684 | 2018.1.01429.S | 69 | The first molecular line inventory in hybrid disks | The transition from the late phase of protoplanetary disks to young debris disks remains a poorly explored evolutionary stage of planet-forming disks. The new class of "hybrid" disks, recently discovered by our team, includes disks with debris disk-like dust properties but having primordial gas content. These disks may represent the protoplanetary to debris disk transition. In order to establish how the chemical properties evolve, we propose to study all four hybrid disks discovered so far, together with five evolved Herbig Ae systems with relatively low gas content as comparison targets. The observations will provide the first inventory of the most important and best observable molecules in these disks. We will characterize their morphology and kinematics, and perform a detailed chemical analysis using our ANDES and ALCHEMIC chemistry codes adapted to these disks. Our program will reveal the chemistry of an independent evolutionary path for the gas component around A-type stars. The measurements are expected to provide final proofs that the gas in hybrid disks is the direct residual of the gas in the Herbig disks. | Debris disks | Disks and planet formation | 2019-12-27T19:59:50.000 |
| 1685 | 2019.1.01365.S | 7 | Is the IMF top-heavy in an intensely star-forming disk at z=2.6? | The ratio of the intensity of the CO isotopologues 13CO/C18O is sensitive to the shape of the stellar initial mass (IMF) function, since the relative abundance of 13C/18O in the ISM is driven by the ratio of high-to-low mass stars. Determining whether a universal IMF can be applied even in the most vigorously star-forming galaxies in the early Universe is a fundamental question of galaxy evolution. We will map the 13CO/C18O ratio in the extraordinarily bright lensed submm galaxy 9io9 at z=2.554. We will determine whether 9io9 follows the trend seen in other IR-luminous starburst systems, with suppressed 13CO/C18O, hinting at a top-heavy IMF. Moreover, we will search for variations in the isotopologue ratio across the source, where gravitational lensing provides access to sub-kpc physical scales in the z=2.554 source plane. We will link any variations to the conditions of the ISM to better understand how 13C/18O can be exploited as an IMF tracer and to explore the properties of this remarkable galaxy in more detail. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-03-10T07:15:58.000 |
| 1686 | 2016.1.00901.S | 3 | Seeing to the Event Horizon: Terahertz Spectra of Sagittarius A* | The millimeter/submillimeter spectrum of the Galactic Center supermassive black hole, Sagittarius A*, originates from within a few Schwarzschild radii of the event horizon. Determination of the turnover frequency and spectral index after the turnover is critical for assessing the optical depth of the emission and the maximum electron temperature present in the accretion flow and/or jet. These measurements will set important boundary conditions for models of the Event Horizon Telescope images of Sgr A*, directly enabling constraints on the nature of accretion and outflow, black hole spin, and tests of general relativity. Specifically, we propose to obtain spectra at frequencies from 230 to 900 GHz (bands 6, 9, and 10) of Sgr A*. There are only limited prior observations for Sgr A* up to 690 GHz and no interferometric observations at 900 GHz. Our ALMA Cycle 2 observations show that the spectrum of Sgr A* is flat between 230 and 345 GHz (bands 6 and 7). The spectrum must turn over steeply at THz frequencies in order to connect with near infrared spectra. Only ALMA can provide this broadband high frequency spectrum and give insights into the event horizon structure of Sgr A*. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-05-09T12:31:30.000 |
| 1687 | 2019.1.01407.S | 83 | Mystery in Deuterium fraction - An evolutionary picture of deuterium chemistry in protostellar phase | We propose to observe H2D+ emission using ACA toward 3 protostellar cores in Perseus. The deuterium fraction N2D+/N2H+ has been used as an evolutionary indicator for protostellar cores as it decreases due to the heating from the central protostar. However, in episodic accretion, the thermal history in protostellar phase becomes more complicated. The cloud cores can be heated up and cooled down several times such that the N2D+/N2H+ ratio being an evolutionary indicator is unclear. Based on our previous CO, DCO+, and N2D+ ALMA survey in 25 protostars, we propose an evolutionary picture of protostellar cores: from a cold-center protostellar core at pre-epidosic accretion phase evolves to a warm-center protostellar core after starting episodic accretion. To confirm that, we propose to observe H2D+, the parent molecular ion of N2D+ and DCO+, toward three representive protostars (Per-emb-4, 20, and 51) from our survey. We will use the H2D+ distribution to check our proposed scenario. This result would provide a standard evolutionary picture of the deuterium fractionation at the protostellar phase. | Low-mass star formation, Astrochemistry | ISM and star formation | 2022-10-01T04:18:22.000 |
| 1688 | 2018.1.01540.S | 16 | Multiscale tests of dense filament and core formation in a magnetized molecular cloud | Molecular clouds, dense filaments, and cores all form out of a magnetized ISM; however the degree to which magnetic fields influence the formation of dense cloud substructures is still an active topic of debate. Here we propose a comprehensive observational study of one of the highest column density regions in the Vela C giant molecular cloud, in which we will directly link (a) cloud-scale magnetic fields measured by extremely sensitive balloon-borne polarimetry, (b) filament scale magnetic fields traced by APEX polarimetry at 870 microns, and (c) sub-filament and core scale fields from ALMA band 4 polarimetry for a 0.1 pc embedded clump. Our proposed observations will trace the magnetic field from 0.007pc to 50pc. By measuring the degree of order in the magnetic field and the orientation of the field direction relative to cloud structure on different size scales, we will determine the dynamical importance of the magnetic field in the different density regimes within Vela C. | Intermediate-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-03-07T21:28:18.000 |
| 1689 | 2021.1.00720.S | 270 | Establishing a timeline for the high-mass star-formation process | Studying the first stages of high-mass star formation is observationally demanding, because the entire early evolution takes place while the young stellar objects (YSOs) are embedded in their parent cloud. In recent years it has become possible to arrange high-mass star forming regions (HMSFRs) on a relative timeline. This, however, does not give any information on the actual age of individual YSOs. With the high-resolution obtainable with ALMA and (new) chemical models, one can better constrain the actual age of these objects. In cold, dense material molecules are locked onto grains, but evaporate into the gas phase at different temperatures, depending on the chemical properties of each species. When this happens their gas phase abundance increases drastically. With the continued heating by the YSO the evaporation fronts will expand making it possible to assign an age to individual YSOs, with the aid of chemical models that link the size of the evaporation region and the luminosity of the YSO to an actual age. We therefore want to observe selected molecules in HMSFRs in different evolutionary phases and compare the derived column densities with the model results. | High-mass star formation, Astrochemistry | ISM and star formation | 2022-11-14T20:34:04.000 |
| 1690 | 2015.1.00311.S | 30 | ALMA probes the SagA* Accretion | We propose to search for HI 30alpha recombination line emission in the accretion zone of the Galactic Center supermassive black hole SgrA*. These observations are stimulated by the the detection of broad HeI line emission in the NIR (Hall etal 1982). The ALMA sensitivity is such that we will easily detect a 0.001 solar masses of HII if the gas density is 10^6 cm^-3 and these numbers are consistent with what one might expect in the accretion zone of SgrA*. This technique offers a vital new window to SgrA* -- X-ray observations can't probe the 10^4 K gas. The submm recombination lines have higher spontaneous decay rates than the cm-wave lines; they therefore can more reliably probe the very high densities which will be in proximity to SgrA*. If the line is detected, it will yield estimates for the mass of ionized gas and the radius where this gas resides from the velocity extent of the emission. The requested resolution of 0.2 arcsec is needed to resolve the emission on the scale of 10^16 cm. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2017-06-28T18:16:37.000 |
| 1691 | 2013.1.00198.S | 25 | Chemical Abundances in Planet-Forming Disks: The Carbon Reservoir | Recent observational results have suggested that the CO abundance in the TW Hya disk is well below the ISM value. This result was enabled by a detection of HD by Herschel that set strong constraints on the total gas content thereby opening a pathway to explore chemical abundances in protoplanetary disks. We propose resolved ALMA observations of simple carbon bearing species in two protoplanetary disks systems of disparate age (TW Hya at 3-10 Myr and DM Tau at 1 Myr) that each have HD detections. We will target transitions of C2H, C3H2 and H2CO (TW Hya; to be combined with cycle 1 observations of C18O) and C2H, C3H2, CH3OH, and C18O (DM Tau) with enough resolution to explore chemical gradients within each disk. Armed with the additional information from HD and dust continuum we will characterize radial abundance gradients relative to H2 (from HD) and CO (from C18O) in each disk in the emissive layers. With these data we can start to explore the question of where the carbon resides in protoplanetary disks, while also setting more stringent constraints on the distribution and evolution of chemical abundances. | Astrochemistry | ISM and star formation | 2016-10-17T02:44:14.000 |
| 1692 | 2021.1.00347.S | 20 | Triggering and supression of star formation in recent gas-rich minor mergers | Galaxy mergers are a crucial part of our galaxy evolution paradigm. Gas-rich & gas-poor mergers have been well studied. However a third intermediate class exists, where one of the merging objects has gas, and the other does not (gas-rich+gas-poor). Such mergers are quite common at low redshift, but have not been well characterised. A recent study suggests that mergers where a gas-rich minor companion is accreted onto a gas-poor central actually lead to very low efficiency star formation, in stark contrast to the starburst often observed in purely gas-rich mergers. In order to understand this phenomenon we here propose to observe a carefully constructed sample of gas-rich+gas-poor & gas-rich minor mergers with ALMA, revealing the compactness/dynamical state of their molecular reservoir, and how this relates to their star formation efficiencies, & those of a robust control sample selected from the literature. A short investment of ALMA time will allow us to reveal how gas gas-rich+gas-poor mergers differ from better studied gas-rich mergers, and lay the ground work for future observational & theoretical efforts to fully resolve the physical processes behind these differences. | Merging and interacting galaxies, Early-type galaxies | Galaxy evolution | 2023-10-26T12:46:57.000 |
| 1693 | 2016.1.01134.S | 9 | Completing the submillimetre portrait of LAB1 | In Cycle 2 we obtained deep Band 7 observations of the original 100kpc Lyman-alpha Blob SSA22-LAB01 (z=3.1). The 0.3" resolution 850um map revealed twin extended (1"-2") submillimetre sources embedded in the heart of the LAB. However, the ALMA observations raise a new mystery: nearly 50% of the total flux measured with a single dish (JCMT/SCUBA-2) is missing in the ALMA map. There is strong evidence for highly extended (possibly up to 40kpc) dust emission in this system with total flux ~2mJy. This dust could be associated with a population of faint satellites, with the circumgalactic medium (CGM), or with tidally disturbed material around the two central sources. These scenarios are testable, and would yield important information on the large-scale distribution of dust around galaxies forming in massive halos at z~3. We will map the extended dust with new Band 7 observations that will bridge the uv-plane coverage between the single dish and Cycle 2 observations, completing the submillimetre continuum portrait of this remarkable object. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2018-04-27T03:05:13.000 |
| 1694 | 2019.1.01329.S | 71 | The physical nature of massive quenched galaxies at z>3.5 | Determining why galaxies stop converting gas into stars is a key unanswered question of galaxy evolution. Multiple processes could play a role in quenching a galaxy, yet evidence is scarce to favor one explanation over the other. Using NIR spectra, we recently discovered quiescent galaxies in the first billion years of the Universe, with properties that models fail to predict. Studying these systems further is necessary to understand the first appearance of quiescent galaxies in the Universe, and give constraints on the quenching models. We propose dust continuum and [CI] observation with ALMA for the spectroscopically confirmed massive quenched galaxies at z > 3.5. Deep dust continuum imaging at Band-7 will enable us to investigate whether these red and massive galaxies have strongly dust-obscured star-formation or are truly quenched. We will also conduct deep [CI] spectroscopy at Band-3 to investigate their cold gas fractions, which will allow us to disentangle the quenching processes with different timescales. These data will provide us with deep insights into how galaxies stop star formation and massive quenched galaxies first appear in the early Universe. | Galaxy structure & evolution | Galaxy evolution | 2022-07-09T17:16:32.000 |
| 1695 | 2013.1.00179.S | 4 | Binary properties encoded in the circumstellar spiral pattern of AFGL 3068 | Theoretical models show the formation of a spiral pattern in the circumstellar envelope (CSE) of an AGB star due to the presence of a binary companion. This spiral pattern preserves the information about the orbital motion of binary stars, and can be used to constrain key binary properties (stellar masses, separation, and orbital inclination) using high-sensitivity high-resolution interferometric observations of the molecular line emission from the CSE. We propose to use ALMA to observe the circumstellar CO(2-1) line emission from the CSE of an extreme carbon star AFGL 3068 to obtain the critical 3D information of its spiral pattern. This pattern has only been observed in a dust scattered light image (thus 2D), leaving a degeneracy in the determination of the binary parameters. The proposed observations will provide new diagnostics to significantly extend the method of mass determination for embedded stars and their companions using our newly-developed model. The resulting determination of the binary properties will be an important step towards theoretical investigations of the effect of binarity on late stellar evolution and the onset of bipolarity at the end of the AGB phase. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2016-12-28T06:07:51.000 |
| 1696 | 2022.1.00477.S | 22 | Constraining the water evolution in an embedded disk around HH100 | Water is a key molecule that can trace the planet formation process and link it to the history of the Solar System. Yet, we still do not know how it is delivered to planet-forming disks. Previous observations of water vapor toward protostellar systems indicate that its abundance is much lower than expected compared to ice observations. The low abundance can be caused by early planet formation or the physical properties of the protostar. By tracing the history of water during the earliest stages of planet formation, it could potentially serve as a tracer of planet formation in various environments. We propose to detect and characterize the warm water vapor emission from a young planet-forming disk around HH100IRS. Cycle 7 and 8 ALMA observations indicate that water lines are tentatively detected. In addition, the same observations reveal the presence of a Keplerian disk around HH100. This program requests deeper observations to spatially resolve the water emission around the Keplerian disk. It will reveal whether water enters the young disk as ice or vapor during the early stages of planet formation which is still missing in the star and planet formation studies. | Astrochemistry | ISM and star formation | 2024-07-28T13:13:28.000 |
| 1697 | 2017.1.00075.S | 28 | Mapping the hot atmospheres of evolved stars | Shocks, convection and stellar activity have a major impact on the circumstellar chemistry and mass loss of evolved AGB stars. Surface and extended atmosphere studies of these stars have so far been limited to the visual to near-infrared wavelength ranges, with limited imaging capabilities, or the marginal resolving power offered at radio wavelengths. Using ALMA long baselines, we have resolved exquisit details of the stellar atmosphere of W Hya and Mira. For W Hya we show numerous hotspots close to the actual stellar photosphere, and a hot gas layer with temperature >5000 K. This firmly proves the existence of a (likely shock-heated) chromosphere that shows stellar activity. Only ALMA can image this activity, as at other wavelengths opacity sources limit our view on the stellar surface. Here we propose to map the stellar disk structure of W Hya and R Leo across three ALMA bands. Such observations are crucial for modeling the structure of AGB atmospheres, as our current results challenge almost all available models that underlie our understanding of AGB mass loss. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-01-22T15:34:02.000 |
| 1698 | 2023.1.01671.S | 0 | Direct calibration of atomic carbon as a molecular gas tracer in M83 | We propose to directly calibrate the relationship between CO, [CI], and H2 emission on the scale of individual molecular clouds in the highly star-forming (SF) core of M83. Hernandez+ 2023 recently reported high (>30%) CO-dark molecular gas fractions in the nucleus of M83, based on direct detections of H2 emission from JWST/MIRI spectroscopy. Such dramatic CO-dark gas fractions in a high-metallicity environment is unexpected, and could have severe implications for models of star formation in dynamic, SF environments at all metallicities. We will obtain ~10 pc resolution maps of [CI] (1-0) and (2-1), which are routinely used as tracers of molecular gas in high-redshift galaxies. These maps will immediately confirm the presence of significant CO-dark, warm H2 gas at the scale of individual molecular clouds in M83. Joint modeling of the dust SED, CO SLED, and non-LTE [CI] SLED (see Papadapoulous+ 2022) will allow us to determine what processes dominate the heating of the ISM in M83s nucleus (FUV photons vs. turbulence / cosmic rays). The observations proposed here will test the limits of existing tools for measuring the properties of molecular gas in external galaxies. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2025-09-13T14:45:15.000 |
| 1699 | 2017.1.00293.S | 19 | Characterizing the accretion structures around the HMYSOs in W51 | The formation process of the most massive O-type stars is one of the main open issues in star formation. There has not yet been a clear detection of a Keplerian accretion disk reported around an O-type forming star. We recently observed accretion structures on ~1000 AU (0.15", resolution 0.04") scales at 1.1 mm, but these structures are far more disordered than the disks seen around low-mass stars. The presence of outflows indicates that the structures are linked to disks on small scales (<500 AU). However, with existing 1 mm data, ths innermost region is obscured by optically thick dust. We propose to image the accretion structures in three well-known high-mass (>20 solar masses) forming stars massive star-forming complex W51 and address the following questions: (1) What are the kinematics on scales <500 AU, where the dust is optically thick at 1 mm but thin at 3 mm? (2) How much of the continuum emission seen on 300 AU scales is free-free emission from ionized gas? What fraction, if any, of the disk is ionized? Are the outflows from these high-mass protostars ionized? (3) Are there large grains in the accretion flow or around the disk? | High-mass star formation | ISM and star formation | 2019-02-02T09:28:53.000 |
| 1700 | 2015.1.01199.S | 25 | A Novel Approach to Observing the Gas-Dissipation Timescale of Protoplanetary Disks | Determining the gas-dissipation timescale in protoplanetary disks is an important quantity for understanding the formation of planetary systems, in particular gas giants. Traditional tracers of the H2 rich gas, such as CO, provide mass estimates with large uncertainties that may increase with disk age. To counter this we use our solar system as a template where there is a clear enhancement in the C/N ratio relative to the solar value in meteorites and comets. This is due to a decrease in the amount of incorporated nitrogen. Thus N may be preferentially available in the gas over longer timescales than C, making N-bearing molecules better tracers of the mass in mature protoplanetary disks. We propose a pilot study to observe N2H+ emission in two ~5-11 Myr-old disks in the Upper Scorpious OB association that have previous ALMA dust continuum and CO measurements. Our aim is to evaluate the ability of N2H+ to act as primordial gas (mainly H2) tracer and our estimates suggest that we have sensitivity to H2 gas masses > 0.004 Msun. Positive results would lead to a future survey of N2H+ in a large number of disks to constrain the gas-dissipation timescale. | Disks around low-mass stars | Disks and planet formation | 2017-04-19T21:56:47.000 |
| 1701 | 2018.1.00717.S | 13 | High angular resolution molecular and dust images of Supernova 1987A | Supernova (SN) 1987A is a unique SN, which modern telescopes can spatially resolve at wavelengths ranging from X-ray to radio. Its time evolution has been monitored over 30 years, revealing how a SN has transformed into a SN remnant in remarkable detail. For the cycle 6 program, we request deep high-angular resolution images of SN 1987A in bands 6, 7 & 9, covering SiO 6-5, SiO 7-6, CO 6-5 and dust 450-micron and 850-micron emission. The combination of these images will give temperature and column density maps of dust and SiO. Furthermore, SiO data provide the 3-dimensional velocity map of this molecule. With these images, we will investigate four science cases. (1) probing potential on-going interaction between ejecta dust and reverse shocks, (2) tracing the past dust formation and investigating chemistry operating in the SN ejecta (3) identifying the neutron star and (4) investigating the proper motion of clumps in the ejecta and its cooling. | Supernovae (SN) ejecta, Pulsars and neutron stars | Stars and stellar evolution | 2020-12-27T14:27:11.000 |
| 1702 | 2016.1.01293.S | 19 | The Structure of a Massive, Dusty Galaxy During Reionization | We request deep, 0.25"-resolution imaging of a unique dusty galaxy in the Epoch of Reionization (EoR), selected via its millimeter-wavelength dust emission in the 2500-square-degree South Pole Telescope (SPT) survey. Spectroscopically confirmed to lie at z=6.900, SPT0311-58 has a large dust mass and is likely one of the most rapidly star-forming objects in the EoR. Although we see no evidence of AGN activity, this galaxy is most similar to the massive quasar host galaxies of its era. We will use the combination of the 158um CII and 88um OIII fine structure lines to determine how such a massive object has been assembled, to map the distribution of star forming regions, and to identify any signatures of the growing black hole that might be expected to accompany rapid stellar mass growth. Deep CII imaging should reveal accreting and outflowing gas, minor merging partners, and other signatures of early galaxy assembly. These observations will also determine whether this source is gravitationally lensed and allow us to model the lensing geometry. These maps will be the first steps toward understanding the most spectacular galaxy discovered by the SPT. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-01-03T20:30:27.000 |
| 1703 | 2021.A.00013.S | 33 | ALMA Observations of the DART Mission: Revealing Composition of the Impact Ejecta and the Interior of S-Type Asteroids | We propose ALMA Cycle 8 DDT observations of ejecta from the DART mission. The DART impact will afford an unprecedented opportunity to remotely characterize the interior composition of an asteroid via high-resolution molecular spectroscopy of the ejecta, excavating relatively unprocessed interior material in the first mission of its kind. Such detailed measurements of interior asteroid composition are ordinarily impossible without exceedingly rare rendezvous missions. Our objectives are to quantify the abundances, distributions, and kinematics of silicate and sulfur compounds that will be liberated from the interior by the impact at high spatial and spectral resolution, thereby addressing key questions regarding the presence of sulfur-bearing species in asteroid regolith. Simultaneous continuum observations will provide the first measure of Didymos' emissivity, revealing highly complementary surface composition information for comparison with the ejecta. These data will yield exceptional insights into asteroid composition to inform our understanding of the terrestrial planet region of the protosolar disk, and can only be measured with the high sensitivity and resolution of ALMA. | Solar system - Asteroids | Solar system | 2023-04-04T15:48:12.000 |
| 1704 | 2019.1.01741.S | 22 | Abundance vs. IMF -- Studying CO isotopologues at z=2-3 | We propose to observe three gravitationally lensed dusty starburst galaxies at z=2-3 with ALMA at 3 mm to measure their 13C16O and 12C18O fluxes and column densities. Elevated ratios of C18O/13CO have recently been presented as evidence of a top-heavy IMF at z=2-3. However, both isotopologues are also commonly used as abundance tracers at low redshift, making their interpretation difficult. We will combine these ALMA measurements with our existing IRAM 12CO and [CI] data to meaure line ratios of 13CO/C18O, 13CO/12CO, and 13CO/[CI] and column densities to distinguish between these scenarios. Each result would be interesting, e.g., finding evidence of changes in abundance would have important ramifications for the on-going discussion about the CO-to-H2 conversion factor. We will use our published multi-line CO LVG modeling and [CI] 1-0 and 2-1 fluxes to constrain the gas conditions as well as possible at z=2-3, and combine these mesasurements with similar IRAM/NOEMA data of brighter, Northern sources, to increase the total number of such observations in the literature from 3 to 12 starbursts, a reasonable sample size for such fundamental astrophysical quantities. | Starburst galaxies | Active galaxies | 2021-06-20T19:49:21.000 |
| 1705 | 2015.1.00934.S | 37 | Investigating molecular gas in disks around young Brown Dwarfs with ALMA | We propose to observe with ALMA the three disks around young very low mass stars and brown dwarfs which have a previous detection of molecular CO. With the proposed high sensitivity, angular resolution and spectral resolution, we will study the gas kinematics and spatial extent with unprecedented details for disks around these very low mass objects. From the gas kinematics we will obtain dynamical estimates for the stellar/sub-stellar mass, thus providing crucial tests for evolutionary models of these objects and for all studies which are based on this fundamental parameter. We will also measure the radius of the disk in gas. This will be compared to the radius in dust obtained for these disks by our previous ALMA observations. The comparison of them will allow us to investigate radial migration of solids in the regime of low disk masses and temperatures, and test the predictions of models of solids evolution in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2017-09-23T21:06:18.000 |
| 1706 | 2022.1.00986.S | 22 | B335: a unique test-bed for COMs variability | Recently, the Bok globule B335, one of the best-studied protostars in an isolated dense core, brightened in the MIR and in ALMA Band 7 observations. Models indicate an increase in luminosity by a factor of 5-7, likely the result of a mass accretion event. In response, the emission lines from COMs increased strongly. This is the first known example of a hot corino varying in real time. Therefore, we propose to observe B335 to track the evolution of the hot corino. By this observation, we aim to detect changes in COMs emission size, as predicted by models, and to test the freeze-out timescale from theoretical calculations. Also, the relative abundances of COMs may be changing in response to the protostellar luminosity variation, opening windows on the ice composition and how the COMs chemistry responds to the enhanced radiation field. | Low-mass star formation, Astrochemistry | ISM and star formation | 2024-08-01T19:17:50.000 |
| 1707 | 2016.2.00014.S | 186 | ALMA Observations of the Most Massive Galaxy Clusters at z > 1 | MaDCoWS is a comprehensive program to detect and characterize the most massive galaxy clusters in the universe at z ~ 1 and above, and is the only all-sky survey sensitive to galaxy clusters at this epoch. The cluster sample resulting from the overall program is designed to be optimal for (1) unbiased calibration of scaling relations for cluster mass estimation techniques (e.g. X-ray, SZ, and weak lensing), (2) identification of extreme mass sources that can be used for cosmological studies such as the f_gas test and measurements of primordial non-Gaussianity, (3) strong lensing studies of cluster concentrations and central mass distributions, as well as identifying lensed high-z targets for ALMA and JWST studies of galaxy formation and reionization, and (4) investigations of the evolution of massive galaxies in the most overdense environments close to their epoch of star formation and mass assembly. Here we propose ALMA ACA observations of 10 of the richest galaxies clusters at z > 1 visible from Chajnantor. With accurate ALMA-measured Sunyaev-Zel'dovich (SZ) masses, this will establish a legacy sample of the most massive (M_vir ~ 10^{15} M_sun) clusters in existence at z > 1. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2018-11-16T16:38:58.000 |
| 1708 | 2017.1.00287.S | 358 | Validating the L850-MH2 calibration with Herschel-ATLAS galaxies up to z~0.4 (resubmission) | Disentangling the physical processes contributing to the decline in the cosmic star formation rate requires the measurement of the interstellar gas content of galaxies out to high redshift, but CO line observations are difficult and time-consuming. The development of a calibration between the dust continuum luminosity at 350 GHz (lambda = 850um) and the molecular gas content provides a more efficient method to infer the gas mass of high redshift galaxies, yet current measurements of the Lv850/MH2 ratio rely on small galaxy samples. How this ratio varies with other galaxy properties remains unknown. We thus propose to use 3.9 hrs of ALMA Band-6 and Band-7 to observe the dust continuum at 350 GHz to an rms of 0.2 mJy/beam, simultaneously tracing the CO(J=3-2) line at 346 GHz, for 34 galaxies selected from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). With this large sample, we will (i) confirm the Lv850/MH2 ratio found in previous studies, (ii) identify any physical properties affecting the shape or scatter in the calibration, and (iii) provide to the community a robust calibration to apply to higher redshift observations. Resubmission of proposal 2016.1.00994.S. | Spiral galaxies | Local Universe | 2019-05-31T16:27:23.000 |
| 1709 | 2018.1.01669.S | 17 | The [CI] lines as dynamical tracers: rotation, outflow, and heating mechanisms in a massive AGN-host starburst at z=2.6 | In Cycle 2 we detected molecular gas in the AGN-host starburst galaxy PKS 0529-549 at z=2.6, using the [CI](2-1) line. The [CI] emission is consistent with a rotating disk: 3D models give a strikingly high Vrot/sigma=10, similar to local galaxy disks. The spatial resolution of the ALMA data (0.4"x0.3"), however, severely limits the interpretation: we cannot categorically exclude other scenarios like a galaxy merger. Moreover, integral-field spectroscopy from SINFONI shows that PKS 0529-549 has an outflow of ionized gas, aligned with two radio lobes, but this is not evident in the current [CI] data. We propose for follow-up observations of both [CI] lines at 0.1" resolution. This will allow us to unambiguously probe the gas kinematics: we will trace the rotation curve (distribution of baryons and dark matter) and investigate the possible molecular phase of the outflow. The ratio of the two [CI] lines will provide the kinetic temperature of the gas, which will be compared to the dust temperature to study gas heating mechanisms. This program will constrain theoretical models of stellar and AGN feedback and provide key insights in the formation and evolution of massive galaxies. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-01-02T17:54:10.000 |
| 1710 | 2011.0.00130.S | 0 | Spectroscopy of a normal star-forming galaxy at z=2 with 300 parsec resolution: physical conditions in the cold ISM at high redshift | We propose band 9 observations of [CII] emission and 630 GHz continuum in the lensed galaxy MACS J0451+0006 (J0451). J0451 is a normal L* star-forming galaxy at z=2.01 magnified by a factor of 49x due to gravitational lensing, such that ALMA's resolution (0.8 arcseconds) corresponds to only 300 parsecs in the source plane. Our extensive observations and accurate lensing mass model yield an intrinsic radius 2.5 kpc, stellar mass 1.4x10^10 Msun, star formation rate 18 Msun/yr, far-infrared luminosity 1.6x10^11 Lsun, and metallicity 0.6 Zsun, all typical of L* galaxies at z=2. We now seek to characterize the physical conditions, spatial distribution, and kinematics of the cold ISM via resolved observations of [CII]. Our specific goals are to (1) determine the physical conditions of the cold ISM in a typical z=2 galaxy; (2) determine the mode of star formation (i.e. extended disk vs. compact central starburst) via the distribution and kinematics of [CII]; (3) compare the spatial distribution and kinematics of the cold ISM (traced by [CII]) with the bright star-forming regions (traced by Halpha); and (4) determine whether the enhanced [CII] emission seen in the most extreme, luminous high-redshift galaxies is also characteristic of fainter L* galaxies, and if so, determine the physical origin. Our proposal will provide the first study of the cold ISM in a typical high-redshift galaxy, and the first high-resolution data necessary to determine the mode of star formation. These observations would not be possible without lensing; similar resolution and sensitivity would normally require several days of integration with the completed ALMA array. J0451 therefore presents a unique opportunity to study the cold ISM in a normal high-redshift galaxy with ALMA early science. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2014-02-19T16:24:00.000 |
| 1711 | 2016.1.00085.S | 311 | Protostellar Multiplicity in Isolation | Multiple star systems are a common outcome of star formation. While the multiplicity frequency and separation distribution are well-characterized for field stars, theoretical studies predict that the majority of multiple systems form very early in the protostellar phase and undergo significant and rapid dynamical evolution. Thus knowledge of the intrinsic multiplicity fraction and separation distribution before modification via dynamical evolution requires studying the youngest objects: protostars still embedded in and accreting from their parent cores. Recent surveys have made great progress in characterizing protostellar multiplicity in clustered environments but have left unanswered a key question: does the formation of multiple systems depend on environment? Here we propose an ALMA band 6 multiplicity survey of 31 truly isolated protostellar cores down to approximately 25 AU resolution in order to measure the protostellar multiplicity fraction and separation distribution in isolated globules and determine the effects of environment on fragmentation. | Low-mass star formation | ISM and star formation | 2019-03-04T15:37:51.000 |
| 1712 | 2016.1.01539.S | 15 | Distribution of dense molecular gas in the active center of Lupus3 | The critical processes on the star formation process occur on spatial scales ranging from 0.05 pc to 100 AU, when the gas moves from dense cloud core onto protostellar envelope scales. These scales determine the mass reservoir of the forming stars, and the number of companions in multiple systems. Lupus is among the nearest low mass star forming clouds in the southern hemisphere, and the central core of Lupus 3 has the right angular size and protostellar density and variety to allow us to measure the gas processes on scales from cores to envelopes using the ACA as a stand alone instrument in Band 6. We will observe CO, 13CO, C18O, H2CO, and DCN lines in Band 6 to sample the large scale gas in the filaments (CO 2-1), high velocity outflow emission (CO 2-1 plus 13CO and C18O for opacity correction), structure of the protostellar envelope (13CO and C18O), and high density (DCN) and temperature (H2CO) gas and dust (in the continuum). Thus, we will obtain a comprehensive dynamical state of Lupus 3 to investigate its internal fragmentation and feedback processes. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-07-26T00:00:00.000 |
| 1713 | 2013.1.00857.S | 30 | The Density (and Destiny) of the Circumnuclear Disk | The innermost concentration of molecular gas in our Galaxy is the Circumnuclear Disk (CND), a ring of gas and dust at a radius of ~1.5 pc from the central supermassive black hole. Depending upon the mass of this gas reservoir, the fate of the CND (whether it will it form stars, or eventually accrete on the black hole) will have a substantial impact on the evolution of the central parsec of our Galaxy. Its fate depends upon its density: gas clumps with densities > 10^7 cm^-3 are stable, and can collapse and form stars, whereas unstable clumps should quickly be sheared apart and eventually accrete onto the black hole. We propose to use the resolution and sensitivity of Cycle 2 ALMA to conduct a robust probe of gas density on the scales of individual clumps (1", or 0.04 pc) via simultaneous excitation analyses of multiple tracers and the inclusion of radiative excitation. Ultimately, this study will yield the authoritative values for the CND mass and density, quantities which vary in recent literature by 3-4 orders of magnitude, and will indicate the amount of gas present in the central parsecs, and whether it will feed the central black hole or contribute to a nuclear starburst. | Starbursts, star formation, Galactic centres/nuclei | Active galaxies | 2016-03-02T17:10:38.000 |
| 1714 | 2015.1.00126.S | 17 | Submillimeter nature of a putative molecular torus in the type-1 low-luminosity AGN of NGC 1097 | The detailed nature of a dusty molecular torus, which is the heart of the unification scheme of active galactic nuclei (AGNs), is still a matter of debate, despite the more than decades-long modeling effort. Here, we propose to observe the CO(3-2) line emission towards the central region of a nearby type-1 low-luminosity AGN, NGC 1097, at 80 mas (5.6 pc) resolution. The 860 micron continuum and HCO+(4-3) line emission will also be detected. With this unprecedented high resolution and sensitivity, we will resolve the innermost r < 20 pc region, where previous observations suggest the presence of a geometrically thick molecular disk. The sphere of influence of this AGN (~ 12 pc) will also be resolved. With these data, we will study the spatial distribution of gas and dust around the AGN and infer the gas kinematics of the region to constrain molecular disk models, as well as to directly estimate the black hole mass. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-01-25T05:42:50.000 |
| 1715 | 2013.1.00105.S | 46 | Completing the disk census in Taurus | We propose to observe 69 single and multiple young stellar systems in Taurus to answer how protoplanetary disk mass depends on both stellar mass and multiplicity. While previous surveys have demonstrated a clear correlation between stellar and disk mass, most sources below spectral type M3 are undetected and it is not known if the same dependence holds down to the stellar mass limit. Our Cycle 0 observations of wide binaries in Taurus detected disk masses down to 10-4 MSun and revealed a range of disk mass distributions. ALMA’s unmatched combination of sensitivity and resolution enables us to observe a complete sample to tackle this issue; these systems will be observed at a sensitivity level over 10 times better than previous large surveys of this region. The sample has been chosen to provide complete coverage of all stars in the disk-only phase by targeting undetected single stars and undetected or unresolved multiple systems. Using these new 1.3mm (Band 6) continuum fluxes as a measure of outer disk mass, combined with the wealth of ancillary data on Taurus, we will be able to establish the influence of stellar mass and multiplicity on the potential for planet formation. | Disks around low-mass stars | Disks and planet formation | 2016-11-12T17:15:09.000 |
| 1716 | 2013.1.00814.S | 23 | Probing the Formation of Nuclear Stellar Cusps | We propose observations with ALMA to spectroscopically map the molecular gas and dust that is associated with the build up of nuclear cusps in late merger stages of Luminous Infrared Galaxies (LIRGs). Our Hubble Space Telescope (HST) near-IR imaging program of the GOALS survey has recently spatially resolved the nuclear stellar structure in 88 LIRGs and revealed an increasing fraction of strong cusps towards late merger stages. ALMA will spatially resolve the morphology of the gas components of the cusp on a scale comparable to that of the HST. We have selected the five strongest cusp galaxies in our sample and a well matched comparison sample of five pre-cusp galaxies. The aim of this proposal is to unveil the molecular gas morphology (CO) and mechanisms associated with cusp formation and to accurately measure how much gas mass is involved in the build-up of stellar cusps. The decomposition of the gas kinematics will provide an unprecedented spatial measurement of the mass-to-light ratio of nuclear cusps and cores, providing a crucial test whether the central dark matter distribution is affected by the cusp/core evolution as seen in the stellar component or not. | Galactic centres/nuclei, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2016-11-06T15:45:14.000 |
| 1717 | 2023.1.00734.S | 0 | The First Map of the Star Formation in a Galaxy at z>3 | The Science Verification observations of the z=3.042 lensed galaxy SDP 81 produced spectacular maps of the ISM with a resolution of ~50 pc, revealing massive clouds of gas in a collapsing disk. The early epoch and the rapid global star-formation rate imply that we are seeing this galaxy during its formation phase. In order to investigate the physical relationship between the ISM and the star formation, we need an independent map of the star-formation rate with a similar resolution. Although there are published star-formation maps for galaxies at z>3, they have all been produced from maps of the ISM by assuming a constant star-formation efficiency and are therefore of no value for investigating star-formation physics (they are essentially scaled maps of the ISM). The only practical method for mapping the star formation in a galaxy at z>3 is to combine ALMA Band-10 observations with ALMA observations in lower bands to map the bolometric dust luminosity. We propose to use this technique to produce the first ever map of the star-formation rate in a z>3 galaxy, which will have a resolution of only 200 pc, the size of a giant molecular cloud association in our galaxy. | Sub-mm Galaxies (SMG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1718 | 2016.1.00389.S | 21 | Characterizing the Envelope-Disk Transition in the Young Protostellar System HH 111 | In star formation, rotationally supported Keplerian disks are expected to form inside flattened collapsing envelopes around the protostars. However, current simulations of magnetized core collapse show that magnetic braking can significantly reduce the angular momentum in the innermost part of the envelopes, potentially preventing such disks from forming in the early phase of star formation. In order to investigate this problem, we have observed the very young Class I system HH 111 in Cycle 1. We indeed detected a substantial loss of angular momentum in the innermost part of the envelope possibly due to magnetic braking. We also found tentative evidence that only a relatively small Keplerian disk of order 100 AU in radius is formed around the central protostar, even though there is significantly more angular momentum on the 1000 AU scale to form a much larger disk. Here, we propose to finish our Cycle-1 project, resolving the structure and kinematics of the innermost part of the envelope and the disk, in order to confirm the Keplerian rotation profile of the disk and to better study the envelope-disk transition. | Low-mass star formation | ISM and star formation | 2017-12-17T02:54:40.000 |
| 1719 | 2017.1.01120.S | 14 | Size ratios in Kuiper Belt Binaries | A surprisingly high fraction of the bodies in the Kuiper Belt are in binary or multiple systems. The physical properties of the components in binary systems are essential constraints on possible binary formation mechanisms including co-formation, collisions, rotational breakup, and dynamical capture. Determining the relative size of binary components, their albedos, and densities can help to characterize formation and evolutionary processes of the outer Solar System. Utilizing the sensitivity and resolution of ALMA, we will obtain thermal images of four binary Kuiper Belt Objects. For each system, we will obtain the first resolved measurements of the two binary components at thermal wavelengths, allowing us to independently derive the size and albedo of each component of a system using the radiometric method. These results will determine the diameter ratio and make the first measurement capable of detecting albedo differences in these four systems. Improved diameter measurements will be used to derive more accurate densities using the system mass determined from the binary orbit. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2018-10-31T01:19:57.000 |
| 1720 | 2024.1.00408.S | 0 | Characterizing the complete disk population of Herbig Ae/Be stars within 1 kpc | This is a survey program to obtain millimeter continuum and CO line flux for the complete population of intermediate and high-mass YSOs within 1 kpc (Herbig Ae/Be stars, 1.5-11 solar mass). Using the ACA, we will cover representatively the whole parameter space of intermediate and high-mass star formation in age, stellar mass, and effective temperature, for a volume-complete population of Herbig Ae/Be stars. Hence, this ACA-standalone survey will provide the means to study the disk evolution, star formation mechanisms, and the planet formation potential of a large sample of disks distributed representatively throughout the whole intermediate and high-mass star formation regime. This will greatly improve the current biases affecting studies on this disk population. We will characterise the population of disks around the more massive Herbig Be stars for the first time, and we will compare the trends we find for Herbig Ae/Be stars with surveys of lower-mass YSOs. In addition, this survey will reveal which disks are bright enough in the continuum and line for follow-up by the community. 32 sources (60% of the proposed sample) are in the LST range encouraged for this Cycle in the ACA. | Disks around high-mass stars | Disks and planet formation | 2025-10-30T04:53:47.000 |
| 1721 | 2021.1.01018.S | 84 | The Birth of Giants: Assembly of the First Massive Galaxies | Over the last decade, a coherent picture of the Universe during the epoch of reionisation has started to emerge. Optical and near-IR spectra of high-redshift quasars have undoubtedly been the most polyvalent tools in the exploration of the first Gyr of the Universe. To obtain a pan-chromatic legacy sample of the brightest quasars at z~6, ESO recently awarded a Large Programme (XQR-30) to obtain optical/near-infrared spectra of the highest quality in a carefully selected sample. Here we request ~1.5 kpc (0.3") resolution ALMA [CII] imaging of this sample of quasars. These observations are critical for a number of reasons: (a) characterise the host galaxy that cannot be traced in the optical/near-infrared and spatially resolve star formation and gas surface densities; (b) provide accurate systemic redshifts that are crucial to fully exploit the optical spectroscopy; (c) pin-down the frequency of merging events in z>6 quasar hosts. Together with accurate black hole masses from XQR-30, the ALMA data will also put the targeted quasars in the framework of the black hole-host galaxy co-evolution paradigm and shed light on the formation of the first massive galaxies. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2023-08-29T12:26:31.000 |
| 1722 | 2024.1.00835.S | 0 | CO 2-1 observations of nearby intermediate massive galaxies of MeerKATs MHONGOOSE survey | Stars form from molecular gas, while most of the gas in nearby galaxies is atomic, making the transformation of HI to H2 and the phase balance of the ISM one of the key elements in understanding galaxy evolution. MeerKAT is now the premier telescope to map 21-cm HI emission from southern galaxies. We propose 12m+ACA CO 2-1 observations of galaxies that are currently getting ultra-deep, high-quality 21-cm maps from MeerKAT's Large Survey Project MHONGOOSE. MHONGOOSE observations will be the deepest observation of HI in nearby galaxies and unsurpassed till the SKA era. We will use this paired ALMA CO and MeerKAT HI data set to gain critical insights on a series of important, but neglected topics: comparing the kinematics and stability of the molecular and atomic gas phases, measuring how the star formation law depends on ISM phase, and testing and improving prescriptions to predict and explain the balance between atomic and molecular gas in galaxies. Our sample of intermediate stellar mass galaxies probes a largely unexplored parameter space where the balance of H2 and HI are the main factor driving the rate of star formation. | Surveys of galaxies | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 1723 | 2021.1.00767.V | 0 | Ultra-high resolution imaging of 3C84 | 3C84 is a prime target for high angular resolution studies of jet formation, due to its proximity and large SMBH mass, which provides a spatial resolution of 20 Rs. Previous 1.3cm RadioAstron space-VLBI imaging and 3mm GMVA maps show a prominent two rail jet, which is anchored in an E-W oriented compact component, perpendicular to the outer jet. With the proposed EHT+ALMA observation we address the question of the physical nature of this elongated jet base and the "true" location of the jet apex. EHT imaging with ultra-high angular resolution will allow for a number of questions to be answered: the Faraday depth, magnetic field and particle density can be estimated through the rotation measure. The location of the jet base will be precisely pinpointed. The transverse jet width and nozzle (profile) will allow for a discrimination between magnetic and/or pressure confinement in the jet launching region. Finally, the magnetic field topology and orientation will be constrained by polarisation imaging. These parameters will set important constraints for the future theoretical modelling of BH jet launching. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-04-24T15:36:02.000 |
| 1724 | 2012.1.00781.S | 2 | IRAS 16272-4837: The birth of a massive protostar | We propose Band 7 observations of the unique IRDC IRAS 16262-4837. This massive dense core hosts one of the most luminous IRAS sources with no counterpart cm radio continuum emission. Furthermore, Spitzer-MIPS and p-Artemis 450 micron continuum detect just two embedded protostars, each with a luminosity of an OB star. Single dish molecular lines trace a compact high velocity outflow arising from this core, and dense gas tracers show clear indication of systematic infall mortions onto the binary protostars. Thus, this source is likely one of the youngest massive protostars in the Galaxy. We will map the core in CO 3-2 and isotopologues to resolve and study the massive molecular outflows arising from this binary protostar. We will also map the core in the HCO+ and H13CO+ 4-3 lines to model de kinematic structure of the infalling envelope onto the protostars. We will use the Lime 3d radiative transfer program to model selfconsistently the infalling core and the molecular outflow cavities from both protostars in molecular lines and dust continuum. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2016-05-13T16:43:31.000 |
| 1725 | 2018.1.01763.S | 4 | Investigating thermal diagnostics of the solar chromospheric network | We propose to use observations from ALMA Bands 3 and 6 to investigate the temperature structure of the solar chromospheric network, and its evolution. Firm constraints on the actual temperature of the network elements, as well as on the duration, and spatio-temporal distribution of individual heating events, will allow us to validate current radiative-magneto-hydrodynamical models of the solar atmosphere, and assess the role of the dissipation of waves vs. magnetic reconnection as the mechanism responsible for network heating. By using temperature maps of the chromospheric network at high temporal resolution, both on disk and near the limb, we will shed light on the presence, and nature, of the ubiquitous, fast evolving spicules observed around the network. Coordinated observations will be obtained together with ALMA at up to three different observatories, providing a broad range complementary chromospheric diagnostics from UV, optical, and NIR spectral lines that can be compared to the ALMA observations to provide a more complete picture of thermal structure of the solar chromosphere. | The Sun | Sun | 2020-03-01T03:14:25.000 |
| 1726 | 2018.A.00009.S | 38 | The unique and massive SPT0348-62 protocluster at z=5.7 | We propose line spectroscopy and continuum imaging towards the densest protocluster discovered so far at any redshift, SPT0348-62, made more remarkable being at z=5.7, less than 1Gyr after the Big Bang. Using ALMA in Cy4, spt0348 was shown to have at least 5 ULIRGs/SMGs detected in dust and C+ emission within 20" (integrated SFR of ~10^4 Msun/yr). Recently, we obtained a deep LABOCA image reaching 1mJy rms, which finds 6 bright sources, peaking at 870um, (870>500>350>250) consistent with the colours of the central SPT source. The proposed observations to resolve these satellite LABOCA sources are urgent and essential to obtain insight into this truly unique protocluster field. Our goals are: (i) determine whether the 6 red LABOCA sources (z~6) are in the protocluster - there is little doubt they are given the rareness of 870um-peaking sources, but redshifts are required to determine the membership and luminosity of the cluster; (ii) use the velocities of the satellites to constrain the dynamical mass of the structure. Even the assumption of fully infalling satellites requires a mass only 2 times less than the virial mass. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2019-11-21T21:01:27.000 |
| 1727 | 2023.1.01175.V | 0 | Imaging M84 and Sombrero at < 50 gravitational radii: jets and accretion inflow | We request EHT+ALMA 230GHz imaging of the twin jet bases of the M84 and Sombrero galaxies. Among the very few AGNs that the EHT can image at <50 gravitational radii, M84 and Sombrero were identified as having a strong (beyond SgrA* and M87) EHT flux in the March 2022 observing run. We thus have the unique opportunity to 'bridge the gap' between SgrA* and M87, and image jet base (after M87) at <50 gravitational radii, and perhaps their black hole shadows (after M87 and SgrA*) if super-resolution imaging is possible. Our immediate aim is to constrain jet launching and collimation theory with the base of the twin jets in M84 and Sombrero: specifically the morphology of the jet base, its lateral profile, core-shift from the black hole, magnetic field, and orientation. Quasi-simultaneous VLBA and GMVA imaging will enable these goals, but the EHT+ALMA observations are the crucial ingredient. The morphology and flux of the nuclear emission will also constrain emission from the accretion inflow and allow constraints on whether future 'super-resolution' imaging can image the black hole shadow in M84 and Sombrero. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 1728 | 2012.1.01087.S | 0 | Water in the Wind of the High Redshift Radio Galaxy MRC 1138-262: Does Molecular Gas Reform in Outflows? | MRC1138-262 at z=2.156 is one of the best studied radio galaxies in the distant Universe. It has all the halmarks of a galaxy that is in the "quenching phase" of AGN feedback -- it is already massive, has a large gas content, and is driving a powerful outflow. A recent detection of the 0-0 H2 S(3) line with Spitzer suggests it has a significant amount of shock heated molecular gas. By analogy with nearby AGN, the question is, how does molecular gas participate in the outflow when such gas should be easily destroyed? One possible mechanism for solving this puzzle is having the molecular gas "reform" on dust grains in the flow. The critical observation is to determine the dynamics, cooling rate, and distribution of the molecular gas in an important cooling line for shocks such as water and determine the relation of these cooling lines to the dust continuum. To begin to address this question, we propose to observe the vigorous outflow in MRC1138-262 in a water, CO(7-6), and [CI]J=2-1 lines that are redshifted into band 6 around 237-256 GHz. By using the C32-3 array, we can acheive sub-arcsecond resolution in the lines and dust continuum to match the resolution of our ground based optical emission line data. If the warm ionized gas and the molecular gas share the same kinematics and the dust has a similar morphology to both the WIM and CMM, then this support the notion that perhaps the molecular gas reforms in the wind on dust grains as has been observed locally in shock regions (e.g. Stephan's Quintet). While this program is obviously only a small step in our developing understanding of the nature of molecules in outflows, it is an important in that it begins to constrain how such molecular outflows develop and are sustained and in an environment which is much more extreme than in local AGN. As such, observing MRC 1138-262 provides strigent tests of our ideas on how the quenching phase of feedback might work. | Outflows, jets, feedback | Active galaxies | 2015-06-06T19:47:04.000 |
| 1729 | 2019.1.01779.T | 9 | The Death Throes of Massive Stars: Early Millimeter Observations of Energetic Explosions in a Dense Medium | The new era of fast-cadence wide-field optical surveys has produced a cornucopia of both known and unknown transients. Supernovae are now discovered routinely within hours of explosion, providing a new window into the end-lives of stars that suggests a period of extreme instability immediately precedes core-collapse. Just this year, an entirely new class of luminous extragalactic explosions was uncovered with properties that defy nearly all basic models, but appear to be stellar explosions in dense aspherical circumstellar material (CSM). We request time on the Atacama Compact Array (ACA) to study the most nearby CSM surrounding these exotic explosions, which encodes the most recent mass-loss history of the stellar progenitor. Given the ready supply of young explosions from ZTF and ATLAS, this is a suitable time to embark on such an investigation to better understand the final stages and extrema of stellar evolution and energy production in collapsing stars. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2021-01-22T14:25:06.000 |
| 1730 | 2011.0.00210.S | 0 | Probing Formation of Keplerian Disks around Protostars | We propose to use ALMA to directly image Keplerian disks forming around protostars in the innermost envelopes. Keplerian disks have been found around pre-main-sequence stars, and intensively studied because they are most probable sites of planet formation. According to the classical picture of star formation, Keplerian disks are naturally formed as a by-product of star formation. We have been using the submillimeter array (SMA) to study the disk formation around protostars, and found that rotation-law of infalling envelopes around protostars may change at the innermost envelopes, which may suggest a hint of disk formation there. However, the sensitivity of the SMA was not high enough to directly image disks forming around these protostars. We will take advantage of unprecedented sensitivity of ALMA, which is extremely better than SMA and other mm-interferometer even in cycle 0 phase, to directly image Keplerian disks forming around protostars. Observational results will be also carefully compared with theoretical calculations of the disk formation around protostars to understand the details of the disk formation mechanism. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2013-11-15T05:44:00.000 |
| 1731 | 2022.1.01135.S | 8 | Spatially resolved deep submm follow-up of z > 6 low-luminosity quasars with approved JWST's stellar light observations | In this program, we will measure [CII] and FIR continuum emission of a sample of 8 low-luminosity quasars at z > 6. All of our sample will be observed by JWST to robustly measure the stellar light of their host galaxies. Combined with the stellar mass data, we will discuss the location of these quasars relative to the star-forming main sequence. Our high resoliution (0.3") observations will also provide a spatially resolved picture of specific star formation rate. These will tell if the quasar feedback (quenching) is in action particularly around the nucleus. As these quasars are likely to be hosted by lower mass galaxies, we can perform a fair comparison of the host galaxy properties with non-AGN normal galaxies (such as provided by ALPINE and REBELS programs studying at comparable cosmic times): we will identify the distinctive properties of quasar hosts, which is crucial to understand the triggering mechanism of quasar activity. Owing to the high resolution, we will also perform dynamical modelings of the host galaxies to obtain their dynamical masses. With these, we will test the usual assumption in z > 6 quasar studies, dynamical mass ~ stellar mass. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-09-15T06:34:19.000 |
| 1732 | 2016.1.00345.S | 96 | The Disk/FLow System in the Massive Protostar IRAS 18566+0408 | The presence of accretion disks and ionized/molecular jets during the formation of B-type stars is a well established fact, but whether this is also the case for high luminosity protostars which will form O-stars is still debated. We propose 0.3" resolution molecular line and continuum observations of IRAS18566+0408 which is one of the most luminous protostars in the Galaxy. We have observed this object with CARMA at 1" resolution and established the presence of a high density and temperature core, with high pressure gas participating in the flow. The proposed observations will allow to study the dense gas on the scale of 2000 AU which is necessary to investigate the formation of individual stars. Besides determining the multiplicity in this core, we will search for evidence of an accretion disk, and constrain its physical properties. We have already obtained matching resolution VLA maps of the ionized jet in IRAS18566+0408, and the ALMA data will allow to study the relationship between ionized and molecular gas, and how the jet connects to the large scale bipolar flow observed in CO(2-1). | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2019-04-09T20:01:32.000 |
| 1733 | 2012.1.00915.S | 0 | Measurements of high-density gas tracers in lensed submillimter galaxies | Submillimeter galaxies (SMGs) constitute a population of high-redshift and heavily dust-obscured galaxies undergoing a phase of intense star formation, accounting for a large part of the total energy emitted in the Universe at far-infrared wavelengths. This population spans the peak epoch of star formation in the Universe, and is believed to be evolutionary linked to quasars and present-day ellipticals. Most star formation takes place in dense cloud cores, traced by molecular species such as HCN, HNC, and HCO+, which have some of the brightest lines after CO. Estimating the dense gas properties in SMGs using these lines is therefore essential in understanding galaxy evolution and the history of obscured star formation in the Universe. To date, the detection of such lines at high redshift has been limited mostly to the brightest quasars. We propose deep ALMA observations of the (3-2) transitions of HCN, HNC, and HCO+ in the lensed SMGs H-ATLAS J090740.0-004200 and J091043.1-000321, at z=1.5746 and z=1.784, respectively. At these redshifts, the targeted lines will fall in ALMA Band 3, and can be obtained in a single tuning in a relative short integration. Because of their large luminosities enhanced by gravitational lensing, favorable redshifts, and availability of ancillary data, these targets are well suited for the ALMA Cycle 1 capabilities. Targeting two SMGs will enable the comparison of the dense gas content between two galaxies characterized by different CO excitation, and will provide a faster progress in this area than has been previously possible. The three chosen lines will provide us with the necessary diagnostics to constrain the total amount of dense gas and its physical properties, estimate the age of the starburst, and look for indications of AGN activity. We aim to obtain the first multi-line diagnostic set for dense gas in high redshift SMGs, showcasing the potential of ALMA to break new ground in the study of obscured star formation at high redshift. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2015-02-28T14:52:39.000 |
| 1734 | 2023.1.00750.S | 0 | Hii gas at Cosmic Noon: An ACA survey of OIII at z = 2.5 to 5 | We aim to do a survey of the [OIII] 88um line in ten dusty star-forming galaxies (DSFGs) detected from Herschel surveys. This will be the first comprehensive follow-up of [OIII]-emission in DSFGs, and we target specifically the peak of cosmic star-formation rate to probe the fraction of high-ionization gas in their dusty photo-dissociation regions (PDRs). These galaxies have well-characterized dust, CO, atomic carbon and ionized carbon emissions from ALMA and ACA. While studies find near-homogeneous dust properties, the varying depletion times, excitation conditions and morphologies suggest a diverse population. In an effort to understand the intrinsic variations in this population, we propose an ACA survey to probe the only PDR region missing from current surveys: the high-excitation conditions seen through [OIII] 88 micron emission. We select a sample of ten luminosity-limited Herschel galaxies at Cosmic Noon (z = 2.5 to 5) with good atmospheric conditions. Finally, the additional dust observations will enable accurate dust continuum fitting, which is currently limited by the poor resolution of the Herschel data. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-07-16T09:51:58.000 |
| 1735 | 2016.1.00697.S | 17 | ALMA Observations of the Molecular Gas in the Nearest Dual AGNs | Major galaxy mergers are particularly important for galaxy evolution as they can funnel fuel (gas) into the center of the galaxy triggering both star formation and an AGN. Thus, as a natural consequence, systems with 2+ accreting supermassive black holes (SMBHs) caught in the act of merging represent a critical stage in galaxy evolution. Several, 17, such dual AGN are known. The properties of the gas in these systems will offer critical clues to the conditions under which both SMBHs can be activated during these encounters and their influence on the host galaxies. We are currently performing a comprehensive multi wavelength study of the physical properties of the gas in all its phases at a critical stage in the merger process: near coalescence, when the two SMBHs are growing simultaneously. Here, we propose to use ALMA band 6 observations to map at high spatial resolution, ~100 pc, the molecular gas distribution and its kinematics in 3 merging galaxy systems for which this is currently possible. These observations will prove instrumental in determining the conditions which are conducive to simultaneous growth of both SMBHs as well as its effect on the host galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2018-10-09T07:31:37.000 |
| 1736 | 2019.1.01026.S | 311 | A Complete Continuum Imaging Survey of Strongly-Lensed, High-Redshift Starbursts | From the South Pole Telescopes 2500 sq. degree survey of the southern sky, we have constructed a catalog of 81 strongly lensed high-redshift dusty star-forming galaxies (DSFGs). These sources were selected at 1.4 mm and have complete APEX/LABOCA, Herschel/SPIRE, PACS, and Spitzer/IRAC imaging, and ALMA 3mm spectroscopy. ALMA has already measured the spectroscopic redshifts for nearly all of these sources. ALMA high resolution 870 micron images have allowed the creation of reliable lens models for slightly over half of the sample. These lens models provide a wealth of information about the background source, including the magnifications and intrinsic source properties. This proposal represents the completion of this source catalog by requesting 870 micron imaging for the final 16 sources. In order to decrease the overhead fractions, we include an additional 23 sources as fillers, which will benefit from higher resolution imaging. This adds 40 min of on-source time without additional overheads, bringing the total request time to 3.58 hours. The completion of this catalog will provide a window into the nature of DSFGs and be an invaluable source for the broader ALMA community. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2021-01-31T14:19:50.000 |
| 1737 | 2013.1.00291.S | 6 | The emergent low-mass cluster B59: how to beat magnetic fields | B59 is the only star-forming site in the quiescent and magnetized Pipe nebula. It contains a small cluster of low-mass protostars and a very twisted magnetic field in comparison with the more pristine regions of the cloud. We propose to perform a detailed dynamical study of B59 using linear polarization observations. These data will reveal the magnetic field morphology in sources in B59 wich are at distinct evolutionary stages: Class 0, I and II. We want to trace the evolution of the magnetic field properties in the three stages. We expect to resolve the field morphology at the dust envelope of Class 0 objects and at the circumstellar disks at Class I and II objects. Since all targets belong to the same (low-turbulent) parental cloud, we will be able to test predictions of magnetized molecular cloud models. As a complement, molecular line data will trace the kinematics of the cores in order to better constrain the possible ambiguity of projection effects in the polarization data. | Low-mass star formation | ISM and star formation | 2018-12-28T00:00:00.000 |
| 1738 | 2019.1.01230.S | 162 | Studying the coronal properties of complete volume-limited sample of accreting supermassive black holes | The compact radio/mm emission observed in most Active Galactic Nuclei (AGN) is thought to be created by self-absorbed synchrotron emission from the accretion disk corona, the region which is also responsible for the X-ray emission. If this was confirmed, then the nuclear mm-emission could be an excellent tracer of AGN activity and of the AGN bolometric luminosity, being largely unaffected by obscuration. With the goal of understanding the origin of the nuclear 100 GHz emission, and its relation with the X-ray radiation, we propose to observe with ALMA, for the first time, a complete sample of nearby AGN with spatial resolutions between 1.5 and 23 pc. Only the exquisite resolution of ALMA can probe these scales, necessary to infer the coronal emission. A tight relation between 100 GHz and X-ray emission would provide very compelling evidence that the same emission mechanism is at work in the two bands. This would also suggest that the detection of flat nuclear mm emission is a reliable tracer of AGN activity, and would provide a new proxy of the bolometric AGN power, possibly more reliable than the X-rays. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2022-08-26T16:27:01.000 |
| 1739 | 2023.1.00402.S | 0 | Measuring accurate gas masses of the planet-forming disks in Lupus | We propose to carry out a systematic survey of N2H+ in a large, mass-limited (Mdust > 1 Mearth, 13CO detected) sample of protoplanetary disks to provide CO-to-H2 ratios and accurate gas disk masses in the Lupus star-forming region. Previous 13CO, C18O and dust continuum observations show CO to be underabundant by up to 2 orders of magnitude beyond what is expected from freeze-out and (isotope-selective) photodissociation. Whether this means that planet-forming disks are generally gas-poor or that carbon is locked up in other compounds than CO is currently unknown. N2H+, a sensitive probe of CO-poor gas, has been shown to directly measure the CO-to-H2 ratio in disks and is thus uniquely positioned to answer this question. Our observations of N2H+, supported by thermochemical models, will allow us correct existing CO-based gas masses for any underabundance of CO, thus providing accurate gas masses. This will allow us to discriminate between the two alternatives (gas poor vs low CO) that have radically different implications for prospective planet formation. Our observations will provide a definitive answer to the ubiquitous low CO - gas mass conundrum posed by planet-forming disks. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 1740 | 2016.1.00440.S | 31 | A Model Independent Study of Turbulence and Temperature in TW Hya | Despite being a cornerstone of the global evolution of a protoplanetary disk and the subsequent formation of planets, turbulence in disks is incredibly poorly constrained observationally. All derivations thus far have been limited to model-fitting, yielding a global average or simple radial power-law profile describing the turbulent line broadening. Theoretical models of turbulence predict strongly localised variations which would not be captured with such methods. We propose to measure, in a model independent way, therefore free of bias from prior assumptions about the disk structure, the radial profile of turbulent line broadening in the TW Hya disk. This will allow us to confront directly models of turbulence and remain unbiased from the distinctly non-parametric features observed in TW Hya in mm-continuum and scattered light. | Disks around low-mass stars | Disks and planet formation | 2017-12-24T02:48:41.000 |
| 1741 | 2018.1.00589.S | 77 | A Resolved Measurement of the (Break of) HCN, H_2, and Star Formation Relations in a Local Starburst Environment | Galaxies follow several scaling `laws' between the amount of star formation and its available fuel. Samples of luminous Galactic clumps follow the extragalactic Gao-Solomon relation between HCN (proxy for the amount of dense gas) and bolometric luminosity (star formation rate). These clumps are key because they dominate the star-formation rate of our Galaxy, and presumably correspond to the typical environments in vigorous star-forming galaxies and starbursts. We propose for the first resolved measurement of scaling laws between HCN, H2 and star formation rate in one of the most luminous star-forming clumps in the Milky Way (W49N, Lbol>10^7 Lsun), including two J-transitions and isotopologues to disentangle optical depth and excitation effects. Our single-dish measurements show that the extragalactic relations are valid in this environment at clump scales. The ALMA data will serve to measure at which scale these relations break, somewhere between the scale of the full clump (6 pc) and of star forming cores (0.1 pc). The results will give important insight on the possible origin of extragalactic star formation relations as the outcome of the physics within cluster forming clumps. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-07-31T20:49:24.000 |
| 1742 | 2019.1.00178.S | 4 | Measuring the magnetic field through CN Zeeman effect in G31.41+0.31 | We want to directly estimate the magnetic field strength towards the Main core in G31.41+0.31 by using the Zeeman splitting of CN. G31.41+0.31 is one of the clearest examples of an hourglass-shaped magnetic field morphology in a high-mass star-forming region. Taking advantage of the simple magnetic field morphology, we propose to observe several transitions of CN at 1mm and 0.2 arcsec of angular resolution and estimate the magnetic field strength along the line of sight. Since CN is a paramagnetic molecule, it shows a strong Zeeman effect under the influence of the magnetic field. Previous SMA 1 arcsec observations have clearly detected CN in absorption towards this core, while previous ALMA 0.2 arcsec dust polarization observations have allowed us to obtain a very rough estimate of the magnetic field by means of the Davis-Chandrasekhar-Fermi method. The Zeeman splitting will allow us to obtain a precise measurement of the magnetic field strength along the line of sight to better constrain the mass-to-flux ratio and to assess the importance of the magnetic field in the dynamics of the Main core in G31. | High-mass star formation | ISM and star formation | 2022-12-22T17:18:09.000 |
| 1743 | 2022.1.01262.S | 132 | What is the role of major mergers in galaxy formation and evolution? | In the local universe, the role of major mergers in triggering enhanced star formation is well-established, primarily based on the evidence that the morphology of many IR-bright galaxies are highly disturbed. In contrast, the significance of major mergers in forming stars at high redshifts is under debate, due to increasing observational evidence of z ~ 1-3 galaxies with copious star-forming clumps without an apparent equal mass companion. However, the fraction of major mergers may be significantly underestimated because visually distinguishing late-stage mergers or post-mergers from isolated systems is exceedingly difficult. We address this problem by mapping CO(2-1) emission at 50 pc scales in 14 disk-like post-mergers in the local universe. By detecting and analyzing the molecular clumps and disk-wide structure in a sample of post-mergers and comparing it to nearby isolated early and late-type systems, we will address the role of major mergers in the formation of molecular clumps in the extended disks. This is particularly important in understanding the formation process of clumpy starbursts and ultimately the role of major mergers in the history of cosmic star formation. | Merging and interacting galaxies | Galaxy evolution | 2024-06-21T02:31:23.000 |
| 1744 | 2015.1.01301.S | 50 | Gas Dissipation through Disk Evolution in Transitional Disk Systems with Large Cavities | It is widely believed that protoplanetary disks dissipate inside-out. In particular, as an intermediate phase from gas-rich primordial disks to gas-poor debris disks, transitional disks that have a cavity in the central region of the disk could be ideal testbeds to catch gas dissipation in progress within their cavities. Here we propose band 6 (1.3 mm) observations of fifteen transitional disk systems with a relatively large (r >0.''15) cavity in dust continuum, especially focusing on CO line emissions (12CO, 13CO and C18O) at a spatial resolution of 0.''2 to estimate the amount of the gas in the cavity of dust continuum. Our goal is to obtain observational evidence of gas-dissipation in progress among transitional disk systems. To determine to what extent the gas is still contained in the cavity, we measure the `depletion facor' of the CO gas, i.e., the flux ratio of the-gas-outside-the-cavity to inside-the-cavity. Systematic and quantitative comparisons of the gas in the cavity will enable to help our understanding of the disk evolution in transitional disk systems. | Disks around low-mass stars | Disks and planet formation | 2018-03-02T00:44:21.000 |
| 1745 | 2018.1.01050.S | 33 | Heavily Resolving The Molecular Gas Layer in a Protoype of Edge-on Galaxies: NGC 4565 | We propose to directly measure the thickness of molecular gas layer in an edge-on galaxy, NGC 4565. This measurement requires high linear resolution (0''.5), high sensitivity (0.15 K for 10 km/s channel width), and wide spatial coverage (600'' by 30''), which is possible by ALMA in a sensible integration time (17 hours for 12-m array). The thickness of molecular gas layer is important in numerous studies of star formations (i.e. deriving the volume density of molecular gas) and galaxy structure (i.e. comparison to the expectation from hydrostatic equilibrium). This measurement would also be an important constraint to study the star formation efficiency per free fall time in the sample of ALMA PHANGS Large Program. Previous measurements have only barely resolved the vertical distribution of molecular gas, or only limited to the central region. Therefore, we propose to overcome these limitations by observing the whole stellar disk (14 kpc in radius) with finer resolution (25 pc) and better sensitivity (about 1 Solar mass per square parsec). | Spiral galaxies | Local Universe | 2023-02-04T14:27:30.000 |
| 1746 | 2021.1.01156.V | 0 | Towards a sample of SMBH shadows, rings, accretion flows and jet bases: exploratory EHT+ALMA flux measurements | The photon ring around the black hole in M87 (billions Msun, powerful jet) has been imaged with the Event Horizon Telescope (EHT), and exciting results on SgrA* (millions Msun, no/weak jet) are in the pipeline. Here we request 6.4 hours of ALMA time to enable EHT+ALMA 230GHz nuclear flux measurements of 8 black holes, as a step towards observing all 16 black holes with bright enough 43 or 86~GHz cores which can be imaged at <100 Schwarzschild radius resolution with the EHT. Our immediate aim is to identify sources in which near-future deep EHT+ALMA imaging can: (a) resolve the jet base thus providing unique and crucial constraints to jet launching theory over a larger parameter space (mass, spin, accretion rate, jet orientation and power); (b) resolve accretion flows and orbiting hotspots, providing unique constraints to accretion theory; and (c) identify SMBHs whose photon rings can be resolved using super-resolution techniques developed by the EHT Collaboration, thus providing additional constraints to gravity theories. This proposal is thus a first step towards leveraging the transformational results coming from M87 and SgrA* to a multi-parametric sample of black holes. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-07-23T12:47:55.000 |
| 1747 | 2021.1.01594.S | 23 | Spectroscopic Follow-up of Two Luminous Galaxy Candidates in the Epoch of Reionization | The exploration of the early universe and luminous sources therein has been significantly advanced through synergistic strategies across multiple facilities. Remarkably, sub-mm follow-up observations by ALMA of high-z source candidates selected from UV-to-near-infrared observations have opened up a new frontier and enabled us to witness the early evolution of galaxies at the early stage of cosmic reionization. We here propose follow-up observations of 2 luminous (MUV~-22) galaxy candidates at z ~8 with ALMA Band 6. These galaxies were selected from one of the approved Cycle1 JWST GO programs. Our goal is to securely determine the redshift of these galaxies via spectral scanning, targeting the [C II] 158m line. The line is detectable with ~30 minutes on-source exposure per source. Detection of [C II] by our observations will confirm these galaxies as one of the most luminous sources in the epoch of reionization and enable future investigation of their ISM properties with the spectroscopic dataset provided by JWST/NIRSpec. Even non-detection will be a valuable outcome, by providing the JWST GO team an opportunity to finalize their observing targets. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 2023-07-13T17:57:41.000 |
| 1748 | 2018.1.01366.S | 55 | Unveiling chemical compositions of high-mass star-forming cores in low metallicity galaxies | Interstellar chemistry in low metallicity environments is crucial to understand chemical processes in the past universe. Prior to this proposal, we conducted spectral line surveys toward molecular clouds in nearby low metallicity galaxies, LMC and SMC, with single-dish telescopes. As a result, we found that molecular clouds in LMC experience chemical processes different from those in our Galaxy. However, the beam size of single-dish telescopes (5-10 pc at LMC) is too large to resolve internal structures of molecular clouds, and emission from star-forming cores (~0.1 pc), which reflect the chemical compositions of molecular gas associated with newly formed stars, is almost diluted out. Here we propose ALMA band 6 and 7 spectral line observations toward high-mass YSOs in LMC/SMC to unveil the impact of low metallicity environments on chemistry of star-forming cores. This proposal should elucidate a possible link between chemical properties of dense molecular gas and metallicity of the host galaxy. Furthermore, this program has potential to identify a hot molecular core in low-metallicity galaxies, which should help understand chemical diversity of complex molecules in our universe. | Astrochemistry, Magellanic Clouds | ISM and star formation | 2019-12-20T13:48:40.000 |
| 1749 | 2016.1.01363.S | 97 | Widespread SiO in IRDCs: Cloud-Cloud Collision Formation of Molecular Cloud Filaments? | Infrared-Dark Clouds (IRDCs) are filamentary molecular clouds believed to represent the initial conditions of massive star and star cluster formation. Several scenarios have been proposed to explain the filamentary structures observed for these clouds: shock-induced formation, flow-driven formation, cloud-cloud collisions ad magnetically-regulated formation. Among them, the cloud-cloud collision scenario predicts that already molecular clouds collide at velocities of some km s-1, yielding cold and filamentary IRDC structures. As a result, relics of the initial cloud-cloud interaction are expected. Recent single-dish high-sensitivity mapping of the SiO (2-1) line toward two quiescent IRDCs (Clouds H and G) shows that this emission is widespread over parsec-scales across both clouds. Here, we propose to image the emission of SiO (2-1) toward Clouds H and G to clearly establish whether this emission arises from the possible inter-shocked layer originated in the initial cloud-cloud collision, or whether widespread SiO is associated with a population of low-mass protostars that remain deeply embedded and undetected at all wavelengths toward these clouds. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-12-09T00:00:00.000 |
| 1750 | 2022.1.01039.S | 32 | CONICS: Cosmic Noon ISM Conditions Survey | The COsmic Noon ISM Conditions Survey (CONICS) is a comprehensive survey of the mass and conditions in the cold interstellar medium (ISM) of 11 star-forming galaxies during the peak of cosmic star formation (z=2-3). Carefully drawn from optically-selected CO(3-2) surveys, these galaxies form the largest, representative sample of star-forming galaxies at this epoch and benefit from exquisite multi-wavelength data. With only two tunings, we will efficiently measure the CO(4-3)+[CI](1-0) and CO(7-6)+[CI](2-0) emission and underlying dust continuum in Bands 4 and 6, providing a homogeneous dataset that is sufficient to constrain the latest generation of radiative transfer models of the cold medium. This program will provide fundamental insights into the boundary conditions for star formation during the peak of the cosmic star formation history by measuring (i) the total mass in cold gas and dust (ii) the physical conditions in the cold molecular medium (e.g., temperature, density). Building on years of investments with ALMA and NOEMA, CONICS will provide the most comprehensive survey of the gas masses and ISM conditions in galaxies at cosmic noon to date. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2024-01-09T15:22:39.000 |
| 1751 | 2023.1.00251.S | 0 | Unveiling a hidden gem: an extraordinarily bright strongly lensed galaxy behind Milky Way dust clouds | We propose a B3 and B4 spectral scan to confirm the redshift of J154506, an exceptionally bright (~130mJy at 500um) and massive extragalactic source at redshift z~5-6.5. ACA spectral scan capabilities, targeting the CO /[CI]/H2O lines over a wide redshift range, are a highly efficient tool for unambiguous redshift confirmation. This will allow deriving a robust lensing model, reconstructing the source plane, and accurately determining its intrinsic properties. In addition, the targeted lines (at least two will be detected) will lead to immediate scientific results such as the determination of gas density and temperature, and robust estimation of the total mass of the molecular gas. Finally, J154506's highly lensed nature will enable spatially resolved follow-up studies that are essential for uncovering the mechanisms driving rapid mass buildup in the early Universe. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-12-24T13:37:35.000 |
| 1752 | 2021.1.00723.S | 46 | Probing the physical condirtion of the extremely high density prestellar core G208.68-19.20-N2 | A compact (r~ 220 au) and extremely dense (> 10^9 cm^-3) object embedded in a filamentary structure has been unveiled in the prestellar core, G208.68-19.20-N2 (G208-N2), in Orion Molecular Cloud 3. This compact object referred as a "nucleus" is likely to be in the evolutionary stage immediately before the onset of star formation. In order to study the physical conditions of the nucleus and filament, we plan to constrain the dust temperature using the continuum emission observed with the high frequency bands of ALMA. If the dust temperature is lower than 10 K, the peak of its spectral energy distribution appears in the submillimeter band that can be accessible with the high frequency bands of ALMA. W also plan to study the gas kinematics, such as gas flow, turbulent decay, and rotation in the vicinity of the nucleus using the ortho-H2D+ line emission at 372 GHz. The light deuterium-bearing species like H2D+ might be the unique probe for dense and cold region where most of the molecular species including N2D+ are heavily depleted onto the dust. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-09-30T13:54:23.000 |
| 1753 | 2021.A.00008.S | 11 | [CII] confirmation of a z = 13.27 galaxy | We propose to robustly confirm/reject the existence of a star-forming galaxy at z=13.27. Recently, a tentative 3.8 sigma detection of [OIII] at 88 microns was reported for this target, dubbed HD1 (Harikane+2021). If confirmed, it would make HD1 the highest-z galaxy known to date. The existence of such a mature galaxy only 300 Myr after the Big Bang has major implications for galaxy formation theories, and sets the stage for future JWST studies. However, a 3.8 sigma single-line detection is both weak and not spectroscopically secure, and may instead be caused by random noise features or CO emission from a low-z foreground galaxy. The community thus deserves a rapid, definitive test to determine which scenario is true; we therefore request DDT observations totalling 7.2 hours, which will robustly detect, if present, the bright [CII] 158 micron fine-structure line (redshifted to Band 4). A non-detection would instead, most likely, imply that HD1 is a z~3.9 passive galaxy, challenging our understanding of quenching when the Universe only was 1.6 Gyr old. This low-risk/high-gain DDT proposal will thus have major implications for studies of galaxy formation and evolution. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2022-09-21T15:17:07.000 |
| 1754 | 2021.2.00096.S | 9 | Investigating a bottleneck in the phosporous cycle, and a search for active volcanism on Venus | Venus hosts an extremely dense, dry, CO2 and sulphur-rich atmosphere, believed to be influenced by volcanic outgassing, yet evidence for present-day (active) volcanism on Venus is scarce. We propose to use the ACA to perform two related studies of Venus's atmosphere, to address its origin, evolution, composition and habitability. Our first objective is to observe the chloride salts NaCl and KCl as direct probes of active volcanic outgassing. Our second objective is to detect the PO and PS molecules to quantify the phosphorous budget in the upper atmosphere, thereby elucidating possible chemical pathways to phosphine (PH3) - a theorized biomarker. | Solar system - Planetary atmospheres | Solar system | 2023-08-16T22:55:37.000 |
| 1755 | 2023.1.01393.S | 0 | Water deuteration in solar-type protostars: an effect of environment? | Water deuterium fractionation is commonly used as a tool to characterize the evolution of water from the earliest stages of the star formation process until its incorporation into planets. So far, the HDO/H2O ratio has been determined towards seven Class 0 protostars. The three isolated sources show an HDO/H2O ratio higher than the clustered sources and it is interpreted as an effect of different initial conditions in the two types of environments. Most recently, the HDO/H2O ratio was investigated towards two Class I objects, which belong to different molecular clouds, and their HDO/H2O ratios were found to be similar to the isolated Class 0 sources. The reason for that would be that they come from regions with a lower source density than the studied clustered Class 0 protostars. The sample is however too limited for firm conclusions. We propose to determine the HDO/H2O ratios in 6 additional protostars with different environments and evolutionary stages to confirm that the environment is the main reason for the different HDO/H2O ratios and that water deuterium fractionation ratio can actually be used as a tracer of the initial conditions from which the protostar forms. | Astrochemistry | ISM and star formation | 2025-09-09T14:55:49.000 |
| 1756 | 2016.1.01468.S | 161 | The nitrogen isotopic ratio in interstellar ices | To which extent planetary systems preserve their interstellar heritage is a central question in astrochemistry. In this context, knowledge on the formation of the solar system brings invaluable insights to our understanding of the formation of planetary systems in general. Yet, the origin of the volatiles in the solar system is not fully known, especially for nitrogen. The isotopic ratio of nitrogen displays unexplained large variations in the Solar system, and one salient problem is that the isotopic ratio of nitrogen in comets is remarkably homogeneous but twice smaller than that on Earth and thrice smaller than that in the Sun. Moreover, these sharp discrepancies cast doubts on our understanding of the formation of comets and their use as tracers of the early Solar system. One solution could be the existence of a secondary reservoir of nitrogen in prestellar ices, which would have been trapped in comets. If this is the case, the isotopic ratio should be different from that of the bulk in gas phase. We propose to use ALMA to accurately measure the isotopic ratio of nitrogen in prestellar volatiles desorbed from ices towards two protostars. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-03-31T16:24:21.000 |
| 1757 | 2015.1.01003.S | 36 | Proper Motions of Gas In the Immediate Vicinity of the Galactic Suppermassive Black Hole | We propose to search for warm neutral gas at high projected velocities along the ling of sight, as an indicator of high possible motions across the line of sight. We propose to use SgrA* as the background source for measuring an absorption line profile, which are hopefully closer to the Galactic Center in high excited state. The high brightness temperature of SgrA* would compensate the low optical depth of faint features. This is a resubmission of our Cycle 1 proposal as it still may not get scheduled within Cycle 2. However, we note that with Cycle 3, we will have two main advantages: (1) Although officially a minimum of 36 telescopes will be available, we anticipate that even more will be operational. This means our raw sensitivity will be improved as compared to Cycle 1 and 2. (2) As we are using absorption against SgrA* to determine our angular resolution, we are not sensitive to which array configurations will be assigned to this project. However, very long baselines will be available in Cycle 3. This does help to suppress extended emission within the primary beam. Also absolute positions will be better defined, which will be important for proper motion studies. | Galactic centres/nuclei | Active galaxies | 2017-10-14T00:00:00.000 |
| 1758 | 2013.1.00262.S | 13 | ALLO: ALMA Lensed Line Observations | We request 3.3 hours of band 6 time to observe [CI] (2-1) and CO (7-6) lines in 5 extremely lensed, but otherwise typical star-forming galaxies at redshifts z=2-3. These galaxies are part of our survey of [CII](158 micron) and [OI] (63 micron) lines with Herschel (the Herschel Extreme Lensing Line Observations 'HELLO'). The HELLO sample of normal galaxies forms an ideal complement to studies of dusty starbursts at z=2. Our propsed ALMA observations reach interesting limits of [CI](2-1)/FIR = 10^{-5.5} in 40 minutes (with overheads) per galaxy. In 2 cases, we will also detect the H2O 2(1,1)-2(0,2) line. Combined with the Herschel [CII] line measurements, the [CI] and CO lines will give a complete picture of the physical conditions, including density, far-ultraviolet flux, temperature, and pressures in atomic and molecular gas. With the [CII], [OI], [CI], and multiple CO lines we will have the total cooling budget and we can determine whether their ISM at z=2 is fundamentally different from the local universe. ALMA's spatial resolution will also allow a study of spatially resolved kinematics of these galaxies, among which some show outflows and some show cold rotation. | Starbursts, star formation | Active galaxies | 2016-08-13T18:02:11.000 |
| 1759 | 2017.1.01411.T | 105 | The Final Evolution of Massive Stars toward Supernovae | In the last few years, the new paradigm shift has been observed in the field of massive star evolution. Several optical observations of core-collapse supernovae (CC-SNe) have led to an emerging picture that the massive stars are much more dynamic in the last few years than widely accepted previously. However, the existence of the very dense circumstellar matter (CSM), created by intensive mass loss in the final few years, has been inferred mainly from the optical observations, interpretation of which includes highly model-dependent analysis of the radiation transfer effects and a combined effect from various alternative processes. We propose ToO observations of one CC-SN at Bands 3 and 6. The quick ToO at the mm wavelengths within ~10 days after the explosion is a unique and the most powerful diagnostics of the CSM environment in the vicinity of the SN progenitor. This relatively handy project (<3 hours) will bring us new and robust information on the yet-unclarified final evolution of massive stars, and may become a good test case to show the great capability of ALMA in the time domain astronomy. | Supernovae (SN) ejecta | Stars and stellar evolution | 2019-06-14T15:31:31.000 |
| 1760 | 2013.1.00521.S | 36 | Isolating the starbursts in the most massive AGN hosts | Using Spitzer, Herschel, SCUBA and LABOCA, we have obtained 12-band 3.6 to 870µm photometry of 71 radio galaxies covering 1 | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2016-09-08T17:56:17.000 |
| 1761 | 2021.1.00675.S | 43 | New constraints on dark matter models with strongly lensed quasars | Gravitationally lensed quasars have been established as a method to detect and quantify low-mass dark matter haloes at cosmological distances. The population of low-mass haloes is dependent on the mass of the dark matter particle, thus investigations of these lenses can give independent constraints on warm dark matter. From our successful pilot programme, we have established that with ALMA observations we can obtain a statistically significant sample of systems suitable for our analysis. By observing the prevalence of flux ratio anomalies in a sample 10 four-image lensed quasar systems, we will robustly test the cold dark matter paradigm in combination with our data in-hand. In a joint analysis with existing data, we expect to be able to exclude thermal relic masses of a warm dark matter particle up to 7 keV from 25 strong lens systems. This constraint will be more stringent than limits inferred with other methods (such as a 3.5 keV limit from the Lyman-alpha forest) and has the advantage that it does not assume a galaxy formation model, so will be an independent test of these other inferences. This proposal is a resubmission of an approved cycle 7 programme that was not completed. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2023-08-24T15:20:09.000 |
| 1762 | 2013.1.01157.S | 0 | IRAS 15398-3359: Very Low Mass Class 0 Protostar? | In star-formation studies, an important target is to understand when and how the rotationally supported disk is formed around the protostar. In order to address this question, we recently conducted the ALMA observations of the CCH (N=4-3) and H2CO (515-414 etc.) lines in Band 7 toward the low-mass Class 0 protostar IRAS 15398-3359 at a resolution of 0."5. We detected a beautiful outflow feature as well as a flattened envelope around the protostar. From the analysis of the outflow structure, the inclination angle of the envelope is estimated to be 10 degree (i.e. almost edge-on). Then, the velocity structure of the envelope is analyzed, and the mass of the protostar is roughly estimated to be as low as 0.02 Msun. Furthermore, the H2CO emission shows a sign of a Keplerian disk. These results will be an important clue to understanding the initial stage of disk formation processes, if confirmed. We here propose to observe the CCH (N=3-2) and H2CO (515-414 etc.) lines in the Band 6 and Band 7 at the resolution of 0."23 and 0."16, respectively. This observation will provide us with a deep insight into the initial stage of disk formation in Class 0 protostars. | Low-mass star formation, Astrochemistry | ISM and star formation | 2016-11-09T18:28:08.000 |
| 1763 | 2021.1.00590.S | 28 | No disk is an island: exploring possible late stage infall on disks in the Lupus clouds | The current text-book description of how protoplanetary disks evolve assumes that, after the dispersion of the protostellar envelope, disks are isolated from the environment. In particular, no late infall of material from the molecular cloud onto the disk is expected in the Class II phase. Detecting such an infall is mainly hampered by the difficulties in carrying out observations at intermediate size of about 200-1000 au, ~1-5 arcsec, the scale between the leftover clouds and the disks. These sizes are too small for single dish telescopes and largely filtered out by interferometry, but accessibe with ALMA in its most compact configuration. However, there are indications from Herschel and scattered light images, CO maps, and theoretical predictions that infall onto disks can continue well into the Class II phase. Detecting such an infall will greatly change our view of star formation and disk evolution, and help to solve some of the current open questions in the field, such as the missing mass budget in planet formation. We propose ALMA ~1" Band 6 mosaics of 4 prototype disks and their environment in the Lupus cloud to reveal the structure and kinematics of the kilo-au environment. | Low-mass star formation | ISM and star formation | 2023-05-31T13:47:52.000 |
| 1764 | 2023.1.00757.S | 0 | Illuminating the dark side of star formation at z > 3 | We propose an ALMA spectral scan observation in band 3 (3mm) to spectroscopically confirm the redshifts of 6 Radio-Selected NIRdark galaxies. The cosmic star formation rate density has been reliably traced back to 10-11 billion years after the Big Bang; however, its evolution is still poorly constrained at earlier cosmic epochs, and biased towards galaxies luminous in the ultraviolet and with low obscuration by dust. An approach to search for dust-obscured galaxies based on their emission at radio wavelength has been recently proved to be very effective in finding candidates at very redshifts. From a radio-selected sample in the COSMOS field, 22 galaxies have been identified to be at zphot>4.5. The contribution of these elusive systems to the SFRD is substantial and can be as high as 40% of the previously known SFRD based on UV-luminous galaxies. However, in order to validate this exciting result it is needed to unambiguously confirm the redshifts of such extremely obscured galaxies. This can be achieved effectively only with the proposed ALMA observations. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-11-19T15:54:23.000 |
| 1765 | 2013.1.00645.S | 3 | Resolving the narrow Kuiper belt analog around epsilon Eridani | The nearby star epsilon Eridani hosts the closest known analog to our Kuiper belt and is the only K dwarf among the ``Fab Four'' prototype debris disk systems first discovered with IRAS. Sub-mm/mm imaging with SCUBA and MAMBO have revealed the presence of a belt of large grains at a radius of ~ 70 AU which is constrained to have a width <~ 6 AU, implying a Kuiper belt analog which is at least as narrow as the one in Fomalhaut recently studied with ALMA and our own classical Kuiper belt.We will obtain ALMA continuum imaging at 230 GHz (1.3mm) in order to provide the first high resolution and high signal to noise sub-mm data for part of the dust ring of the epsilon Eridani system. The proximity of epsilon Eridani (3.2 pc) makes this the best debris disk to constrain the narrowness of its planetesimal belt. The data will resolve the width of the ring for the first time, setting constraints on the mechanisms which maintain such narrow rings, such as planetesimal shepherding by planets. Additionally it may identify the presence of clumps suggested by previous single-dish images interpreted as planetesimals trapped in resonance with an unseen planet. | Debris disks | Disks and planet formation | 2016-07-31T08:16:47.000 |
| 1766 | 2023.1.00991.S | 0 | A shocking exploration of phosphorus astrochemistry | Phosphorus remains an an astrochemical enigma in dense star-forming regions: while the emission of PN and PO seems to be correlated with shocks, we still do not understand the underlying chemistry. With only two spatially resolved detections of P molecules to date, additional resolved observations are urgently needed to make progress. This program will target phosphrous molecules towards three nearby protostars with diverse shock environments and bright single-dish detections of PN, providing an ideal test bed for exploring the drivers of phosphorus astrochemistry. By covering PN and PO lines in ALMA Bands 3, 4, and 6 at 1" resolution, we will constrain the molecular column densities, excitation conditions, and emission origins. With this we can test, for the first time, what conditions are needed to eject P into the gas, and how the gas-phase P chemistry depends on a wide range of environmental factors. This program will help illuminate the journey of phosphorus, a key bioelement, in dense star-forming regions. And, with an improved understanding of their chemistry, gas-phase P molecules may become a valuable probe of the chemistry and physics of astrophysical shocks. | Astrochemistry | ISM and star formation | 2025-09-27T16:32:29.000 |
| 1767 | 2018.1.00037.S | 36 | The nature of a rotating dense gaseous torus in NGC 1068 | We propose the longest-baseline ALMA band 6 observation of the nucleus of the prototypical type-2 AGN, NGC 1068. Our Cycle-4 data of HCN J=3-2 and HCO+ J=3-2 lines have revealed clearly, for the first time, the long-sought-after rotation of dense molecular gas along the putative torus direction around a central mass-accreting supermassive black hole (SMBH). However, we have also found surprising torus properties, when compared to a classical torus picture; (1) the torus dense molecular emission is highly asymmetric, and (2) rotation at a few pc scale is far from Keplerian motion. With the proposed 0.02" (~1pc) resolution data of HCN and HCO+ J=3-2 lines, as well as the isotopologue H13CN J=3-2 line, we will (1) investigate the origin of the asymmetric dense molecular emission, (2) derive mass distribution of the torus from the optically-thin isotopologue line, and (3) search for mass inflow signatures and Keplerian velocity increase toward the central SMBH. This is a crucial step toward understanding the dusty gaseous torus in an AGN. Since our observing strategy is based on the clearly detected emission lines in our ALMA Cycle-4 data, our feasibility estimate is highly secure. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2020-11-07T00:24:49.000 |
| 1768 | 2015.1.00513.S | 4 | Anatomy of a Fried Egg | IRAS 17163-3907 was recently identified %by Lagadec et al (2011) as the closest and brightest Yellow Hypergiant. Infrared imaging of the dust emission implies a very intense mass-loss, with 2-4~Msun of gas ejected in the last 500 years. This led to the formation of at least two concentric dusty shells. This makes IRAS~17163 a unique object for the study of the mass-loss process in a spectacular short-lived phase towards the end of the life of a massive star, before it explodes as a supernova. Our Cycle 2 proposal to observe it was accepted, but only compact array observations were taken, enabling us to discover the formation of a swept-up ISM bubble around this Yellow Hypergiant.We propose to complete our observations and study these shells in CO J=2-1 emission with ALMA, to probe the kinematics and morphology of the gas in this massive stellar envelope. This will enable us to measure the amount of gas ejected, the time scale of the ejection and check whether the dust and gas ejection are coupled. These measurements are the key for understanding the physics of the intense mass loss during this short-lived, and thus rare, phase of stellar evolution. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2017-01-29T10:44:42.000 |
| 1769 | 2017.1.01334.S | 38 | Non accreting proto-planetary discs: a new evolutionary class? | The aim of this proposal is to observe three unusual protoplanetary discs in the young (2-3 Myr), nearby (~160 pc) Chameleon I region: they have a large IR excess but do not show any detectable accretion, contrary to the conventional picture of disc evolution in which accretion and IR excess disappear at the same time as the disc is dissipated. The targets have a measured sub-mm continuum but no gas detection in an ALMA Cycle 2 survey, opening the question whether they are gas depleted and transitioning to the discless phase. We propose a sensitive search of gas emission lines (CO isotopologues) to establish their gas content, allowing us to assess whether they are young, optically thick debris discs (i.e., little or no gas left over), gas rich discs with inefficient angular momentum transport, or low mass discs that are surprisingly resilient to photo-evaporation. In any case, we would gain insight on a class of object that has received little attention up to now. ALMA is the only instrument sensitive enough to perform such a search. | Disks around low-mass stars | Disks and planet formation | 2019-02-22T04:43:16.000 |
| 1770 | 2015.1.00030.S | 2 | Resolving the molecular gas within 100 pc of M87's supermassive black hole | The proximity of M87 (3C 274), the archetypical giant elliptical radio galaxy at the centre of the Virgo galaxy cluster, presents a unique opportunity to investigate in detail the circumnuclear molecular gas revealed first by CO J=1-0 observations with the IRAM 30-m and more recently imaged for the first time with ALMA (this team's Cycle 1 data). The preliminary results from the ALMA data show that the molecular gas is unresolved and resides within 100~pc of the supermassive black hole (SMBH). With this Cycle 3 proposal we wish to obtain 0.12'' (~10~pc) imaging of the CO J=1-0 line to unambiguously resolve the molecular gas structures for the first time, allowing us to investigate the nature and origin of molecular gas that resides within the 3.1'' sphere of influence (SOI) of the SMBH in unprecedented detail. Such observations are only now possible with ALMA's long baseline capability. | Galactic centres/nuclei | Active galaxies | 2018-09-20T00:00:00.000 |
| 1771 | 2024.1.01556.S | 0 | Tracking the Impact of Luminous Accretion Outbursts on Massive Protostars | The recent discovery of accretion outbursts in massive protostars has motivated new hydrodynamic simulations of protostellar accretion, that suggest massive stars gain up to ~50% of their total mass from episodic accretion. Such outbursts can dramatically increase the dust continuum emission (a proxy for luminosity), trigger strong maser flares, and significantly alter their hot core astrochemistry. However, still little is known about the characteristics of the decline and long-term impact. Monitoring of the outbursts from the NGC6334I-MM1 and G358.93-0.03MM1 over the last 9 and 5 years respectively show declining continuum and maser emission, but also remarkable changes in the spectral lines. As of 2022 the G358.93 CH3CN transitions had increased by 40%, methanol vt=1 dropped by 40%, and methanol vt=0 unchanged compared to 3 years prior. Our goal is to follow the evolution of these two objects with a new epoch of multi-band (sub)millimeter line and continuum images. With these data we will track the post-burst luminosity decline via the dust continuum light curve and measure the resulting changes in the gas chemistry. | High-mass star formation | ISM and star formation | 2025-11-01T15:30:56.000 |
| 1772 | 2012.1.00621.S | 8 | Proper Motions of Gas in the Immediate Vicinity of the Galactic Supermassive Black Hole | We propose to search for neutral gas at high projected velocities along the line of sight, as an indicator of high possible motions across the line of sight. We propose to use SgrA* as the background source for measuring an absorption line profile. This utilizes the high brightness temperature of SgrA* to compensate for the low optical depth of faint features. By using high excitation lines in the submillimeter bands (HCN(J=4-3),HCO+(J=4-3),CS(J=7-6),H13CN(J=4-3),HC15N(J=4-3)), we will sample material which are hopefully closer to the Galactic Center. This will also minimize confusion from the lower excitation material, which will not populate the higher energy levels of the molecules. We propose to utilize SgrA* to provide an effective “delta-function pencil beam”. This improves upon the normal synthesized beam provided by the interferometer. With the multi-epoch measurements, our goals are: (1) detect and measure the line profile of high excitation transitions in absorption against SgrA*, (2) measure the time variation of the proper motions of the clouds in front of SgrA*, (3) measure the chemical species that survive immediately surrounding SgrA*. | Galactic centres/nuclei | Active galaxies | 2017-10-14T00:00:00.000 |
| 1773 | 2013.1.00446.S | 3 | Characterizing the Atmosphere and Surface of Pluto | We will use the unmatched sensitivity of ALMA to make significant advances in understanding of Pluto's atmosphere and surface. The atmosphere exhibits sublimation-condensation exchanges with surface ices and active photochemisty, but is poorly characterized. Our goals: * Atmospheric CO detection, vastly improving determination of its abundance, with implications for the nature of surface-atmosphere interaction and constraining atmospheric temperature * Sensitive search for photochemically produced nitriles like HCN which play major roles in the atmospheric budget * High SNR individual brightness temperature measurements of Pluto and Charon, and determination of their submm surface emissivities Our observations are designed to measure important aspects of Pluto and Charon that only ALMA can provide. The New Horizons spacecraft will fly through the Pluto system in July 2015. Our measurements are both distinct from (CO and nitrile abundances) and complementary to (upper atmospheric structure; relation to hazes; surface Tb and emissivity properties) New Horizons observations. They will serve as benchmarks for the study of dwarf planets and other Kuiper Belt objects. | Solar system - Planetary atmospheres, Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2016-07-23T12:00:26.000 |
| 1774 | 2022.1.00687.S | 10 | Search for Molecular Gas Nebulae surrounding Galaxy Groups | The circumgalactic medium (CGM) is the venue where traces of outflowing material expelled from galaxies and inflows of gas from dark matter filaments are found. To understand how galaxies evolve, it becomes crucial to constrain the physical properties of the CGM across all phases (molecular, neutral and ionized). We propose to observe with ACA the extended molecular gas emission associated with two galaxy groups at redshift z ~ 0.5. There is already a wealth of archival data available for both these targets from MUSE, ALMA and HST. The detection would be the first of its kind around 'normal' galaxies at this redshift and allow us to link the molecular, neutral and ionized gas phases with the SFR, metallicity and stellar mass of galaxies in the group. | Merging and interacting galaxies, Outflows, jets, feedback | Galaxy evolution | 2024-09-11T12:34:17.000 |
| 1775 | 2019.1.00110.S | 9 | Dynamical Properties of Dusty Star-Forming Galaxies in the Peak Epoch of Star Formation | Dusty star-forming galaxies (DSFGs) at high redshift are thought to be predominantly highly dissipative mergers of gas-rich galaxies representing extreme, short-lived starbursts. This picture is supported by studies of gas dynamics, but unfortunately, the resolution of such investigations typically remained limited to 3-4 kpc in the past, which is barely adequate to resolve the galaxies. Using the advanced capabilities of ALMA and the magnifying effect provided by gravitational lensing, we here propose to study the [CII] gas dynamics in 4 strongly-lensed Herschel-selected DSFGs in Einstein Ring configurations, covering the peak epoch of galaxy formation (z=2-6) down to 100-500pc resolution. Enabled by uv plane lens modeling (pioneered by our group) and dynamical models, we will carry out a comprehensive investigation of the occurance rate of major mergers vs. disks in our sample, measure dynamical masses and gas fractions, and constrain the physical properties of individual gas clumps down to unprecedented physical scales at high redshift. The proposed lens configurations will also be ideal to study dark matter halo substructure - allowing our analysis to unfold its full potential. | Starburst galaxies, Gravitational lenses | Active galaxies | 2022-07-08T20:45:20.000 |
| 1776 | 2018.1.00579.T | 21 | Radio Polarimetry of GRB Afterglows | Gamma-Ray Bursts (GRBs) are currently being exploited as probes of the first generation of stars. Therefore, ongoing research aimed at understanding GRB progenitor stars represents one of the most pressing inquiries in modern astrophysics. Undoubtedly one of the most critical measurements is the Faraday depolarization along with spectrum evolution caused by non-energized electron, which requires the revision of the standard mass of the progenitor star. As we demonstrated by making the first radio polarization measurement with our Cycle 5 program, linear polarizations in Band3 with the high sensitivity are essential for discovering these non-energized electrons, because the Faraday depolarization caused by the non-energized electrons suppress the linear polarization degree at a frequency of 100-1000 GHz. In this program, we intend to conduct linear polarlimetry at the millimeter wavelength (Band3) together with simultaneous ACA photometry (Band7). The intensive studies of non-energized electron in a number of afterglows will make a revolutionary change in the GRB progenitors, because diversity of GRB prompt emissions and afterglows are likely linking with type of progenitor stars. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-12-24T03:14:01.000 |
| 1777 | 2016.1.00184.S | 17 | High-Resolution [Cii] Imaging of the Most Luminous Galaxy | The WISE mission has identified a rare population of high-redshift, hyper-luminous infrared galaxies, all with bolometric luminosities above 10^13 L_Sun, and many exceeding 10^14 L_Sun. Characterized by their extremely red mid-IR colors and very hot dust temperatures, these hot, dust obscured galaxies (Hot DOGs) likely probe a key stage in the galaxy evolution paradigm. During Cycle-2 we obtained band 7 observations of the highest redshift Hot DOG W2246-0526 at z=4.601, which has been shown to be the most luminous unlensed galaxy or quasar known. These observations showed a rich reservoir of ionized gas in this galaxy through a highly significant detection of the [CII] emission line. The very bright [CII] flux observed for W2246-0526 enables the chance to obtain with ALMA an unprecedentedly detailed distribution of the gas in such a high-z, unlensed galaxy. Here we request 0.06" resolution observations of the [CII] emission line and study in detail the host galaxy of this remarkable object. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-10-09T07:31:37.000 |
| 1778 | 2011.0.00767.S | 0 | The [CII] Line Study of a Star-forming Galaxy in the Epoch of Cosmic Reionization | Detecting galaxies from the local to the highest redshift Universe, including the epoch of cosmic reionization at z > 6, and characterizing their star formation activity and physical properties are obviously a key issue to understand the formation and evolution of galaxies as well as disentangle the relationship between the diverse populations of galaxies. While star formation and dynamics of low-z galaxies have been well studied using the CO lines as a tracer, those of high-z galaxies have not due to its faintness.Meanwhile, the ionized carbon 158 micron [CII]line can be a powerful alternative to detect high-z galaxies, because it is the strongest cooling line of ISM in galaxies and observable at submm/mm when redshifted to z >6. The ALMA can detect high-z [CII]line only in a few hours and resolve galaxies in this line emission on a few kpc scales, enabling to probe obscured star formation and constrain the sizes, the dynamical masses and ISM in early star-forming galaxies at the epoch of reionization for the first time.Here, we propose the ALMA [CII]line observation of a star-forming galaxy at z >6. We particularly propose to target a z = 6.96 galaxy IOK-1, because it is one of the spectroscopically confirmed highest-class redshift objects in the epoch of reionization and we have a lot of information about this galaxy that can be compared with the ALMA observation. Using IOK-1 as a probe, we will (1) reveal the relation between high-z and local star-forming galaxies, (2) estimate obscured SFR at z~7, (3) investigate the morphology, dynamics and physical properties of a z~7 galaxy, (4) to constrain the physical states of ISM in a z~7 galaxy. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2014-02-27T15:42:00.000 |
| 1779 | 2017.1.00394.S | 19 | [CII] and Continuum High Resolution map of a Quasar Host formed through a wet merger of galaxies at z=4.4. | The z=4.4 quasar BRI 1335-0417 provides the unique opportunity to study the ISM of a quasar host galaxy in unprecedented detail. Our high-quality, 0.2" (~1kpc) resolution imaging of the CO(2-1) emission (using the VLA in an unparalleled effort, >50 hour integration) demonstrates that the molecular gas in the host galaxy is distributed over 10 kpc, and is dynamically complex, hinting at an ongoing gas-rich ('wet') merger. This is the highest-quality/resolution CO dataset available for any unlensed high-redshift source accessible with ALMA. We here propose to complement this dataset with spatially-matched [CII] (and underlying continuum) emission. This is possible given the recent detection of strong [CII] emission in the source using APEX. In only 1.2 hours of on-source integration with ALMA, we will map the [CII] and underlying continuum at kpc resolution and unprecedented sensitivity. Together with the CO imaging, this will provide the first beam-matched dataset of a high-z galaxy to study the interplay of star formation (as traced through [CII] and FIR emission), central black hole accretion (through unresolved FIR emission) and the molecular gas reservoir (CO). | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-01-31T02:51:35.000 |
| 1780 | 2017.1.00297.S | 476 | An ALMA-ACA Survey of CO(2-1) in PG QSOs | We propose ALMA ACA-only observations for a sample of 24 southern z<0.1 PG QSOs to characterize their gas contents and kinematics via CO(2-1). These powerful QSOs are well characterized across the EM spectrum, yet our knowledge of their gas reserviors, which may directly relate to their AGN power, remains biased/incomplete. The all-sky nature of this basic survey is naturally suited to undersubscribed ACA, and will provide a uniform characterization of the CO properties of this important sample, unlocking the potential for future follow-up. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-02-02T21:10:46.000 |
| 1781 | 2012.1.00031.S | 0 | A Survey of Dense Cores in Chamaeleon I | Recent interferometric surveys of "starless" cores haved found that 1) 5-20% of these objects actually harbor low-luminosity star-forming objects and 2) that none of the truly starless cores have any detectable substructure or evidence for fragmentation. However, these surveys were intentionally biased and suffer from small sample sizes. Here we propose to carry out a 3mm continuum and CO (1-0) survey of the Chamaeleon I molecular cloud, targeting all 60 "starless" cores and all 13 positively identified young stellar objects. This survey will enable the first accurate, uniform, and high resolution census of dense cores in a molecular cloud, classifying them as being starless or protostellar. The properties of these cores and the relative numbers in each phase will allow us to study the time evolution of the star formation process and accretion timescales. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2015-02-24T22:34:33.000 |
| 1782 | 2018.1.00378.S | 16 | ALMA CO Survey of the Brightest X-Ray Supernova Remnants in the Nearby Spiral Galaxy M33 | Investigating the interstellar gas associated with supernova remnants (SNRs) is important in understanding the origins of both synchrotron X-rays and thermal X-rays, via magnetic field amplification and ionization of neutral gas, respectively. Most recently, we revealed the giant molecular clouds (GMC) possibly interacting with the 8 X-ray brightest SNRs in the spiral galaxy M33 using the CO data of the IRAM 30-m single dish telescope. However, we could not resolve molecular clouds along the SNR shells due to the coarse angular resolution of the IRAM CO data of ~12 arcsec (~50 pc resolution at the distance of M33). To clarify the cloud association and physical properties of molecular clouds (mass and density), we need further CO observations with finer angular resolution of at least an arcsecond. Here, we propose CO 2-1 observations toward the GMCs in the M33 SNRs using ALMA with an angular resolution of ~0.5 arcsec (~2 pc resolution at the distance of M33). ALMA's unprecedented sensitivity and spatial resolution will allow us to study the shock-cloud interaction in the M33 SNRs for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-12-25T16:06:12.000 |
| 1783 | 2013.1.01155.S | 9 | ALMA Observations of the Most Luminous Young Stellar Object in the Large Magellanic Cloud | We propose to probe the dense circumstellar environment of the most luminous young stellar object (YSO) in the Large Magellanic Cloud (LMC) and among the most luminous forming stars detected in any galaxy. Our recent Herschel Space Observatory key program HERITAGE performed a uniform far-IR survey of the LMC, and using these observations we identifed thousands of YSOs in the LMC, including the proposed target, which we have determined to have a total luminosity of approximately 10^6 L_sun, making it the most luminous forming star in the LMC. To understand how stars with such tremendous masses form, we must observe them during their short-lived formation stages. We propose band 3 ALMA observations of this massive YSO of CO, 13CO, C18O, HCO+, HCN, and 1 mm continuum to 1) determine its multiplicity, 2) accurately determine the physical properties of the star-forming clump/core(s) (masses, densities, line widths, etc.), and 3) measure the feedback from the massive star into the surrounding medium. We will use 12CO to trace the high velocity, low density outflow, while C18O, 13CO, HCN, and HCO+ will be used to trace the low-velocity, high-density gas perturbed by the wind. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2016-11-27T06:16:52.000 |
| 1784 | 2021.1.00348.S | 3 | Measuring the magnetic field through CN Zeeman effect in G31.41+0.31 | This proposal aims to estimate the magnetic field strength toward G31.41+0.31 (G31) by using the Zeeman splitting of CN. G31 is one of the clearest examples of magnetically regulated high-mass star formation. Taking advantage of the simple magnetic field morphology, which has been successfully modelled with an almost pure 3-D poloidal (hour-glass) field, we propose to observe several transitions of CN(1-0) at 3mm and 1.2 arcsec resolution to estimate the magnetic field strength along the line of sight. Since CN is a paramagnetic molecule, it shows a strong Zeeman effect under the influence of the magnetic field. Previous ALMA 1.2 arcsec observations of G31 have clearly detected CN in absorption with all the hyperfine transitions well resolved and unblended, and SMA 1 arcsec and ALMA 0.2 arcsec dust polarization observations have allowed to roughly estimate the magnetic field strength by using the Davis-Chandrasekhar-Fermi method. Zeeman splitting will allow us to obtain a precise measurement of the magnetic field strength along the line of sight to better constrain the mass-to-flux ratio and to directly confirm the importance of the magnetic field in the dynamics of the G31 core. | High-mass star formation | ISM and star formation | 2024-06-14T19:50:54.000 |
| 1785 | 2019.1.00900.S | 22 | How is star-formation quenched at high redshift? Looking for clues by observing post-starburst galaxies | Despite decades of investigation, galaxy quenching is a missing piece in galaxy formation and evolution models. Capturing galaxies during their main quenching phase and estimating their molecular gas content are the key to constrain the processes responsible for the cessation of star formation. Here we propose to observe four post-starburst (k+a) galaxies at z=1.1-1.4 in Band 4. The optical spectra showing deep Balmer absorption lines and little or no [OII]3727 nebular emission make these massive galaxies (Mstar>1e10.6Msun) bonafide quenching objects after a star formation burst occurred <1Gyr prior z~1. With the proposed observations we aim at (i) detecting CO(3-2) and dust continuum emission at rest-frame 1mm (for individual objects and through stacking), to constrain the molecular gas masses and fractions in two independent ways; (ii) estimate the star formation efficiency and place these objects on the Schmidt-Kennicutt relation; (iii) correlate all these quantities with age, morphology, and size, so to constrain the main quenching mechanism at work at high-redshift (gas removal vs gas heating/efficiency reduction), compared to what observed in the local Universe. | Starbursts, star formation, Early-type galaxies | Active galaxies | 2021-04-17T06:22:44.000 |
| 1786 | 2017.1.00914.S | 496 | Extending SPARKS: Exploring the origin of single high-mass protostars, and rich clusters | ALMA is the only instrument to revolutionize our understanding of the early evolution of high-mass protostars, which is one of the main open issues in today's astrophysics. In our Cycle 2 project, SPARKS, we targeted a homogenous sample of 35 objects from the most massive infrared-quiet clumps selected from the ATLASGAL survey. SPARKS has been very successful reaching its science goals: we discovered the highest mass young protostars with envelope masses up to 130 AU within 2000 AU scales, and revealed excellent candidates of high-mass prestellar cores. At the same time, SPARKS revealed very intriguing fragmentation properties: single high-mass protostars with very high core formation efficiency versus typically low-mass protostars forming clusters. It is clear that now we need to understand the origin of these extrem routes of fragmentiation, and to search for more examples of these extreme fragmentation are crucial. Since the number of the most massive infrared quiet clumps in the inner Galaxy is limited, the only possible way to search for them, is to complete and extend the sample of all infrared quiet massive clumps up to 4.5 kpc from ATLASGAL. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-10-19T17:54:12.000 |
| 1787 | 2012.1.00550.S | 2 | First images of a protoplanetary disk around a very massive protostar | One of the most important questions in the field of star formation is to test whether very massive stars (i.e., stars that will become O-type stars) form by accretion from circumstellar disks (as is the case for low-mass stars) or whether other mechanisms are at work. IRAS 16547--4247 is the most massive protostar associated with collimated jets (ATCA and the VLA) and a rotating molecular structure (SMA), which may be confirmed as a disk by observations with a higher angular resolution. We propose to undertake ALMA observations of several tracers of dense gas that will provide a critical test of the presence of an accretion disk around this source. In particular,we hope to discover the first evidence of a Keplerian signature (inner parts rotating faster than the outer parts) in a disk associated with a massive forming star. The confirmation of an accretion disk around a massive forming star will not only prove that they form by a mechanism analogous to solar-type stars but will also open the possibility of studying the physical conditions of these disks and asking whether they can form planets as well as brown dwarfs and even stars. As part of the project, we will also search for recombination lines from the powerful thermal jet associated with this source. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2016-08-17T15:04:24.000 |
| 1788 | 2016.2.00200.S | 194 | The hybrid disk phenomenon over the stellar mass range | Based on ALMA observations, our group recently identified a new class of young (10-50 Myr) circumstellar disks that exhibit debris disk-like dust properties but have large amounts of CO gas of primordial origin. These "hybrid disks" may be the missing links between the protoplanetary and debris disk phases. So far, hybrid disks are only found around A-type stars. Our proposal has two main goals: (1) use CO isotopologue observations to decide on the hybrid nature of two known CO-bearing debris disks around A-type stars; and (2) look for gas in ten massive debris disks around F-M-type members of nearby young moving groups. By combining our results with previous ALMA data, we will have an almost complete survey of young debris disks with high fractional luminosity within 150 pc covering the A-M spectral type range. This will allow us to determine how the incidence of hybrid disks varies over the stellar mass range of 0.5-3 solar masses. If we find that hybrid disks are exclusive to A-type stars, this would imply that these stars can retain their primordial gas much longer, allowing significantly more time, e.g., for the in situ formation of wide separation Uranus-like planets. | Debris disks | Disks and planet formation | 2018-09-11T14:30:20.000 |
| 1789 | 2013.1.00989.S | 10 | Probing the inner-most region of the relativistic jet in extreme TeV blazars | We propose to observe continuum spectrum of five extreme TeV blazars, which are unique probe to study enigmatic extragalactic background light (EBL), for the first time in mm/sub-mm regimes at two frequencies. The goal of this study is to investigate whether their relativistic jets are optically thin at mm wavelengths. Our preparatory study with ALMA shows optically thin mm-spectrum in most normal blazars, contrary to the most accepted "one-zone SED model" predicting their relativistic jets are optically thick in mm regime. In addition, our study with VLBI does not favor it also for extreme TeV blazars. If mm emission is optically thin in also extreme TeV blazars, it requires alternative models such as the structured jet model where both of high-energy emission and mm emission can come from the jet base. It will not only give a new picture of jets in blazars, but also affect studies on EBL based on SED models. These sources are faint for other radio interferometers. Furthermore, sequential observation in two bands is necessary for this proposal, since blazars are usually variable within days-weeks at mm/sub-mm wavelengths. Only ALMA cycle-2 can perform proposed observations. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-07-16T10:10:42.000 |
| 1790 | 2016.1.01141.S | 101 | Formation and Evolutionary Processes of Low-mass YSOs in Lupus | The Lupus star forming regions are among the nearest, low-mass star-forming complexes, and together they host objects spanning evolutionary stages from pre-stellar to pre-MS. By studying members of the same region, environmental factors can be considered sufficiently comparable. We plan to observe 8 objects from prestellar to protostellar phases. These sources are chosen from our group's multi-wavelength source catalog and Band 7 observations in Cycle 2. Our molecular line selection in Band 6 will probe the dense cores (N2D+, C18O, continuum) and molecular outflows (CO, SiO). We aim to reveal formation and evolution processes of cores -- composed of envelopes and circumstellar disks -- through their morphology, velocity structure, density structure, and angular momentum distribution. Complementarily, the outflow opening angles and dynamical timescales constrain mass accretion mechanisms and disk formation. Our selection of sources within regions at the same environment, with identical observing strategy, allows for consistent comparison of sources within our sample and across evolutionary stages. | Outflows, jets and ionized winds, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-11-06T00:00:00.000 |
| 1791 | 2011.0.00628.S | 0 | Disks and complex organics in the inner regions of low-mass protostars | One of the key questions that ALMA will address is how circumstellar disks form around low-mass protostars and how their physics and chemistry evolve until the planet-forming stages. We here propose to observe a range of transitions from isotopologues of common molecular species (H13CO+, C34S) and of complex organic molecules tracing the inner few hundred AU of two embedded low-mass protostars. These observations will address two coupled questions about low-mass star formation prompted by recent ground-based submillimeter interferometric observations: what is the origin of complex organic molecules around low-mass protostars and when are rotationally supported disks formed around such sources? This is made possible with the angular resolution and sensitivity offered by ALMA in its extended array in cycle 0. A key facet of these observations will be the spatial resolution and the sensitivity to reveal emission from complex molecules and relate those to the density distribution and kinematical profile revealed in H13CO+ and C34S on few hundred AU scales. | Disks around low-mass stars, Astrochemistry | Disks and planet formation | 2014-08-12T13:52:46.000 |
| 1792 | 2015.1.00723.S | 16 | Dissecting the colossi: confronting recent theory with two multi-merging HyLIRGs | Amongst sub-mm galaxies (SMGs), only a handful are hyperluminous infrared galaxies (HyLIRGs; > 10^13 solar luminosities in the IR). For a standard IMF, a HyLIRG hosts a staggering star formation rate of > 1000 solar masses per year for a very short (Myrs) period. Exploiting the relationship between CO luminosity and line width determined for fainter starbursts, we have identified and removed lensed sources from the widest {\it Herschel} extragalactic imaging surveys to yield a sample of rare, intrinsically luminous galaxies. Panchromatic observations of the two best HyLIRG candidates led to the discovery of at least two components on each system, each of them being an excepcionally bright, gas-rich HyLIRG. We propose to observe our two excepcionally bright merging HyLIRGs in CO, CI and H2O at high resolution (0.20'') with the aim of studying in detail their kinematic, the morphology of their gas and dust, and explore the presence of molecular outflows. These observations will be compared with the most recent hydrodynamic simulations of isolated and merging galaxies, providing important clues of the evolution of these unique systems. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-03-13T14:45:45.000 |
| 1793 | 2021.1.00657.T | 6 | Revealing the Structure and Magnetization of GRB Jets with ALMA Polarization Observations | Polarization measurements of the afterglows of long-duration gamma-ray bursts (GRBs) probe the structure and magnetization of their relativistic jets, revealing the nature of their elusive central engine. While reverse shock (RS) polarization probes magnetic field structure in the jet, polarized forward shock (FS) emission is sensitive to the jet angular structure and viewing geometry. The ideal window to search for these polarization signatures is in ALMA Band 3, where both components are observable longer than at higher frequencies, while still being unaffected by interstellar scintillation and depolarization from synchrotron self-absorption. Pioneering ALMA Cycle 6 full Stokes observations of GRB 190114C uncovered polarized RS emission at 97 GHz (the first detection of radio/mm polarization in a GRB), yielding direct measurements of the angular coherence scale and magnetic field geometry in the jet. We now propose to triple the sample with linear polarimetry of up to two new GRB afterglows to determine whether the low level of polarization (1%) seen in GRB 190114C is common, aiming to constrain the central engine and jet acceleration mechanisms in these relativistic transients. | Transients | Stars and stellar evolution | 2024-02-07T16:11:14.000 |
| 1794 | 2015.1.00412.S | 146 | Chemistry in the Brightest Luminous-Infrared Merger | We propose to fill a large gap in extragalactic spectral surveys by observing NGC 3256, the most luminous galaxy within z=0.01. This galaxy is the brightest on the sky among the luminous infrared galaxies (LIRGs) powered by merger-induced galaxy-wide starburst. This class, whose energy source is known to be starburst (not an AGN), is the majority of the luminous LIRGs (11.5 ~ < log L(IR) < 12). Also, they are ~10 times more luminous than NGC 253 and M82. Yet disproportionally little attention has been paid for its astrochemical properties. We will observe key molecular tracers in multiple transitions in Bands 3 and 6, and compare the derived chemical abundances to those in Arp 220, a ULIRG having very compact energy source(s), NGC 253, a local starburst, and the Seyfert nucleus of NGC 1068, as well as other sources with spectral scans. Principal component analysis will reveal the effects of merger and high-luminosity in the chemical composition. | Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2017-06-09T01:03:19.000 |
| 1795 | 2018.1.01291.S | 54 | Searching for the Water Snow Line in Circumstellar Disks of Eruptive Stars | The location of the water snow line in protoplanetary disks is key to various planetary formation processes including the transport of water to the surfaces of terrestrial planets. While the presence of this snow line has long been predicted, its identification in resolved imaging has been complicated by its temperature dependent location which typically lies within 1-5 au for Solar mass stars. During an ALMA campaign to characterize the disks and outflows surrounding accretion-enhanced outbursting FUor protostars, we obtained the first resolved images exhibiting signatures of the water snow line in a protoplanetary disk. The presence of the snow line in an outbursting protostar, whose increase in luminosity has caused the location of the snow line to move from ~3 au to 43 au, indicates that the radial position of water ice may be more variable throughout protostellar evolution than previously believed. We propose ALMA band-6 continuum observations at 0.025'' resolution (10 au) to identify the location of water snow lines in two more FUor disks, solidifying the prevalence of such a feature and confirming its variable position during protostellar evolution and planet formation. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2020-12-24T20:50:55.000 |
| 1796 | 2015.1.00241.S | 16 | Star formation in the 1000 km/s shock of Stephan's Quintet | Stephan's Quintet galaxy group is one of these must-do targets revealing surprises each time being looked at by a new instrument. The most striking feature is a giant intergalactic shock created by a 1000km/s galaxy collision, with very low star formation despite an amount of warm molecular hydrogen comparable to the molecular content of the Milky Way. Our Herschel [CII] and IRAM 30m CO(1-0) measurements show that the gas kinematics are complex (FWHM=1000 km/s) on large scales (10 kpc). PdBI CO(1-0) observations reveal molecular complexes of 2-5kpc in size, but with star formation efficiencies varying by a factor of 20. Why? We propose to map the CO(2-1) and SiO(2-1) emission at spatial resolution of 0.2"=80pc, comparable to the size of Giant Molecular Clouds (GMCs), to measure the gas turbulence on scales where gravitationally bound clouds may form, and identify whether the star-forming regions in the shock are the sites of dissipation of kinetic energy through molecular shocks. These ALMA observations will characterize the role of the energy cascade, from bulk motions to turbulent motions on GMC scales, on the regulation of star formation in extremely turbulent environments. | Merging and interacting galaxies, Galaxy groups and clusters | Galaxy evolution | 2018-01-17T17:08:55.000 |
| 1797 | 2017.1.01340.S | 0 | A pilot search for new FIR absorbers at z~1 on three gravitaionally lensed SPT sources | Observations of absorption lines from the foreground intervening gas in the spectra of background bright sources have allowed direct constraints on gas abundances. This technique has been widely used in UV/optical/NIR for over a decade, however such studies in FIR/submillimeter at cosmological distances (z>0.1) are restricted to only three gravitationally lensed systems, and new absorbers have not been found for over a decade. Our 2500 degree-square SPT survey has uncovered over 100 bright submillimeter galaxies, the majority of which are strong galaxy-galaxy lensed so ideal for searches of new FIR absorbers. In this pilot study we propose to target prominent absorption lines in CI and CO, on three lensing systems at z~1. The foreground lens galaxies have confirmed spectroscopic redshifts and star-forming activites based on their optical spectra. We aim to directly measure the abundances of CI and CO in the line-of-sight and compare the results to galactic molecular clouds as well as other FIR absorbers. Discovery of any absorber will provide a major step forward in the studies of FIR absorption, and lead to a full search in our SPT sample. | Galaxy structure & evolution | Galaxy evolution | 2019-11-22T16:26:32.000 |
| 1798 | 2016.1.01150.S | 11 | Linking interstellar and cometary O2: A deep search for 16O18O in a solar system precursor | The detection of O2 in comet 67P/C-G by the Rosetta-ROSINA team with a high abundance of 3.7% w.r.t. H2O was one of the biggest scientific surprises of 2015. The Rosetta team argued convincingly that the O2 must be of primordial nature, i.e., coming from the interstellar cloud from which our solar system formed. Astrochemical model predictions suggest that a high abundance of O2 is only found to match the cometary value for relatively warm and dense cloud conditions. However, interstellar O2 gas is notoriously difficult to detect, making the origin of cometary O2 a conundrum. In this proposal, we propose to carry out a deep search for O2, through its 16O18O isotopolog, toward the warm compact gas surrounding the chemically richest solar-type protostar IRAS16293 -2422, where ices have just been sublimated. The unique sensitivity offered by ALMA will allow us to detect O2 down to a four times deeper abundance (at 3 sigma) than the cometary values and therefore to assess whether high primordial abundances of O2 ice are indeed associated with forming solar-mass protostars through a comparison with other ALMA and Rosetta datasets. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-02-17T17:07:07.000 |
| 1799 | 2012.1.00463.S | 4 | VVV-WIT-01: A Supernova in the Milky Way or an Entirely New Kind of Variable Star | A search of the VVV 1st Data Release led to the discovery of WIT-01, a very high amplitude variable with unusual colors from amongst 50 million sources (Minniti et al. 2012, ATel 4041). WIT-01 is very red: H-Ks=5.2 mag, and invisible in the Z, Y and J passbands. The very rapid decline in flux by >6.5 magnitudes plus the very red colors are unprecedented, and inconsistent with known examples of variable stars. Therefore, this object would have to be the prototype of a new sub-class of pre main sequence (PMS) variable, or an even more exciting possibility, it could be a highly extincted supernova in the Milky Way, detected at some time after maximum light. We request observations with ALMA to prove or disprove the SNe hypothesis by determining the spectral index of the millimetre continuum emission. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-09-01T12:55:46.000 |
| 1800 | 2017.A.00034.S | 90 | Witnessing the Formation of a Spiral Galaxy in the Early Universe | Disk dominated spiral galaxies account for 72% of all galaxies in the local universe, but we do not know exactly when and how these galaxies formed. By combining Cycle 3 and 5 ALMA data taken toward AzTEC 4, a bright unlensed Submillimeter Galaxy forming stars at > 1000 Msun/yr, we have found the first direct evidence of a formation site of a spiral galaxy in the very early universe. This is in direct contradiction to the common belief that bright submillimeter galaxies evolve into spheroidal dominated early type galaxies. Photometric redshift suggests that this source is located at z~5, right at the end of the Epoch of Reionization. However, this is not spectroscopically confirmed. The purpose of this DDT request is to obtain the spectroscopic redshift of this intriguing source by scanning the Band 3 frequency range. Once the redshift is confirmed, this will become the first direct evidence of spiral galaxy formation at the very early universe, offering significant constraints to theoretical models of galaxy formation and evolution. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-10-18T10:03:44.000 |
| 1801 | 2018.1.00859.S | 75 | Molecular gas across the CGM of Enormous Ly-alpha Nebulae | Massive galaxies at high-z are known to co-evolve with their circum-galactic medium (CGM), generally detected in Ly-alpha. Absorption-line work showed that this CGM hosts large amounts of cool (~10^4 K) metal-enriched gas, likely in dense clumps, with large covering fraction. But a critical connection between the CGM and the stellar growth of massive galaxies has remained missing: we had yet to identify the reservoir of halo gas that has enough mass to fuel widespread star-formation, namely the cold molecular gas (~10-100 K). Following our discovery of CO and [CI] in the Spiderweb Nebula, we propose to use the exquisite surface-brightness sensitivity of ALMA in its most compact configurations to image the [CI] 3P1-3P0 tracer of cold molecular gas across ~250 kpc in two of the most enigmatic Enormous Lya Nebulae (ELANe), the Mammoth and Slug Nebulae at z~2.3. We recently detected extended CO(1-0) across these nebulae. ALMA will reveal the mass, chemistry and nature of these Lya nebulae, and their role in the early evolution of a massive galaxy. Studying extended reservoirs of cold gas across the CGM with ALMA opens a powerful new window on galaxy formation in the Early Universe. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2020-02-28T03:07:01.000 |
| 1802 | 2015.1.00057.S | 24 | Rosette Globulettes | Our previous observations and modelling of very tiny molecular clouds, called globulettes, that reside in HII regions surrounding young stellar clusters, open a number of questions regarding their nature and fate. Why do most objects lack tails and bright Halpha-emitting rims? How long can they survive in the hot nebular gas and UV radiation field? Are they gravitationally unstable to form free-floating planetary mass objects and low-mass brown dwarfs to be ejected into interstellar space? Our modelling suggests that globulettes may have a complex structure with a dense, cold core surrounded by thinner gas but enclosed by an outer dense and warm shell. Only with ALMA we can resolve the internal structure of globulettes for the first time. We have selected two representative globulettes in the Rosette Nebula for closer inspection. | Inter-Stellar Medium (ISM)/Molecular clouds, HII regions | ISM and star formation | 2017-08-25T10:33:47.000 |
| 1803 | 2015.1.01323.S | 28 | Characterizing the possibilities of planet formation in the hostile enviroment of Carina | Proplyds, a singular class of young stellar object (YSO), were originally discovered in the Orion Nebula. Elsewhere, reliable proplyd candidates have only been found in the Carina Nebula, where harsher ionizing conditions prevail in the center of this star-forming region. Proplyds stand as unique astrophysical laboratories for studying the survival possibilities of circumstellar disks evolving in ambients dominated by extreme irradiation. Thus, studies of these special targets have ramifications for the planet formation efficiency in massive stellar clusters, where most of the stars are probably formed. This proposal aims to determine the proplyd masses in the Carina Nebula and to set observational constraints to the efficiency of extreme external photoevaporation in circumstellar disk models. The results will help us to determine whether or not proplyds subjected to extreme irradiation can host planetary systems, and whether or not the formation of planetary systems is plausible in rich and young stellar clusters. | Disks around high-mass stars | Disks and planet formation | 2016-12-28T15:11:26.000 |
| 1804 | 2017.1.00363.S | 18 | Molecular gas in the symbiotic stellar system R Aqr | This is a resubmission of a cycle 4 project, after incorporating the comments from the TAC and data from very recent ALMA observations. We propose to map the molecular gas in the symbiotic stellar system (SS) R Aqr. R Aqr is a prototypical SS, an interacting binary with an AGB star plus a compact white dwarf (WD). It is a weak emitter in CO lines, nevertheless it is the strongest among SSs. Previous low-resolution data suggest that CO emission mainly comes from a very small region around the AGB star, about 0.1" wide, comparable to the binary orbit. This clump is very probably gas ejected by the AGB, not yet photodissociated by the WD UV emission, that feeds an accretion disk and therefore powers the symbiotic phenomenon. The compact clump was confirmed by recent ALMA data (2012.1.00524.S, by S. Ramstedt et al.), which also show faint emission occupying about 1" in total. We propose to map with high resolution, 0.035", CO J=3-2 and J=6-5 lines in R Aqr, to study the properties of the molecular gas and, hopefully, obtain a direct description of the mass transfer from the AGB to the WD. Continuum maps at these wavelengths will accurately measure the relative positions of the stars. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-01-09T02:32:07.000 |
| 1805 | 2015.1.00415.S | 2 | Direct Mass Measurements of Supermassive Black Holes in Distant Gravitational Lens Galaxies | Gravitational lensing allows a direct measurement of the masses of supermassive black holes (SMBH) at cosmological distances through the flux of the central demagnified image, which is sensitive to the central mass distribution of the lens galaxy. The high sensitivity and resolution of ALMA provides a new opportunity to search for these central images, which previously have been extremely difficult to detect. Our work with ALMA observations of the lens SDP.81 has shown that even a non-detection can place relevant constraints on the SMBH mass. We propose for ALMA imaging of the lens SDP.9 to detect the central image and thus constrain its SMBH mass. This system represents the best chance to detect a central image due to the known lens and source redshifts, the high luminosity of the source, a known CO flux, the double image configuration (producing brighter central images than quad configurations), and the availability of existing HST imaging to measure the lens core radius. Our proposed ALMA observations of SDP.9 will open a completely new territory of direct SMBH mass measurements in galaxies at z>0.4 given current and future samples of hundreds of lensed submillimeter galaxies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-03-10T09:29:06.000 |
| 1806 | 2022.1.01203.S | 4685 | The Initial Conditions for Massive Star Formation in inner and outer Galaxy | The initial conditions of massive star formation are not well understood observationally. This greatly limits theoretical exploration. Lack of a promising sample has greatly affected previous ALMA surveys (including ours) on "starless" clumps, most of which turn out to be not truly starless (i.e., not "initial" conditions). Thanks to newly available and updated catalogs of HiGAL and ATLASGAL clumps, we make a robust source selection of the youngest (L/M<1 Lsun/Msun, mostly <0.2) massive clumps both in the inner and outer Galaxy. We propose a Band 6+3 snapshot survey for a first glimpse of these promising sites to characterize and compare the initial conditions in various Galactic environments (inner/outer Galaxy, on/off spiral arms, on/off large filaments). Our unique setup enables systematic measure of the N2D+/N2H+ deuteration for the first time in hundreds of sources, a key indicator for bona fide starless cores. Sensitive dust continuum images will reveal whether/how starless clumps fragment to dense cores, a highly debated process in different theories of massive star formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2024-01-27T23:21:45.000 |
| 1807 | 2015.1.01469.S | 103 | Final Piece of the Puzzle: What Drives the Enhanced X-ray Emission from the Most Powerful Jets in the Early Universe | We propose ALMA observations of 15 highly radio-loud quasars at z>4 to obtain their far-infrared luminosity and investigate its correlation with their X-ray luminosity. A positive correlation between these two quantities may indicate a dominating jet-linked X-ray emission mechanism of inverse Compton scattering of the host-galaxy photon field produced by a starburst. With this mechanism, the enhanced star-forming activity at high redshifts can also explain the X-ray emission enhancement of these objects over their counterparts at lower redshifts. The lack of such far-infrared/X-ray correlation would support an alternative mechanism of the inverse Compton scattering of the cosmic microwave background photons. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-03-10T18:31:29.000 |
| 1808 | 2016.2.00060.S | 297 | How extreme are the extreme star-forming hosts of optically-bright quasars at 2 < z < 4? | We propose band 7 continuum ACA stand-alone observations of the most infrared-luminous type 1 quasar hosts in the Herschel HerS and HeLMS fields. The proposed observations will establish whether the Herschel-SPIRE fluxes come from a single component alone, placing the hosts of these type 1 quasars among the most extreme star formers in the Universe with SED-derived star formation rates (SFRs) above 1000 solar masses per year, that will immediately chanllenge the models for galaxy assembly. If not, we will resolve the SPIRE fluxes into multiple components, allowing for revised SFRs. Such multiplicity could either be the result of unrelated sources lying closely to one another in projection but far apart in redshift, or real oversensities, in which case we will have immediately identified a sample of high-redshift overdense region candidates around type 1 quasars, hosting multiple starbursts, that will be ideal targets for follow up observations. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-07-15T01:31:16.000 |
| 1809 | 2021.1.00966.S | 360 | Towards a sample of SMBH shadows, rings, accretion flows and jet bases: ACA fluxes of SMBHs with large photon rings | The photon ring around the black hole in M87 (billions Msun, powerful jet) has been imaged with the Event Horizon Telescope (EHT), and exciting results on SgrA* (millions Msun, no/weak jet) are in the pipeline. With the commissioning of ALMA passive-phasing, new telescopes, and larger bandwidths, the EHT+ALMA can now image sources down 10s of mJy. A dozen additional galaxies have photon rings likely large enough to be resolved by the EHT, but they are relatively faint at centimeter radio,and their 230 GHz is unknown. Our immediate aim is to measure the 230 GHz nuclear flux of 23 SMBHs with photon ring size > 5 microarcsec (piggy-backing an additional 15 SMBHs with photon ring size > 2 microarcsec). Those found to have a nuclear flux >= 10mJy will be followed up at higher resolution (12m array and VLBA). Our longer term goal is to identify all SMBHs in which the EHT can resolve the photon ring and jet base and drive the technical requirements of the next-generation-EHT. Identification of one to a few new EHT-feasible targets will allow us to leverage the transformational results of the EHT in M87 and SgrA* to a larger number of galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-04-08T22:39:00.000 |
| 1810 | 2018.A.00020.T | 37 | CO(3-2) spectroscopy of first GRB detected at TeV energies | This is an urgent DDT to observe GRB 190114C, the first gamma-ray burst (GRB) detected at TeV energies. This event also has one of the densest lines of sight towards a GRB afterglow to date, which makes it ideal for observing molecular absorption. This observation will help us understand the connection between the very dense environment of this GRB and the very high energy emission. The observation will cover the CO(3-2) transition at a redshift of 0.4252. We expect to detect this transition both in absorption and in emission. VLT/X-shooter spectroscopy has revealed that the line of sight is very dense; it has the strongest NaID ever seen for a GRB and for the first time we have detected DIBs in a GRB. Detecting molecular absorptions with ALMA would be a first for GRBs. At the same time we expect to see CO emission from the host galaxy which is more massive than usual GRB hosts. These data will be combined with optical and near infrared afterglow spectroscopy obtained with X-shooter at the VLT, and with an extensive follow-up campaign in radio from another ALMA programme, from ATCA and from GMRT to produce an extensive study of the interstellar medium. | Gamma Ray Bursts (GRB) | Cosmology | 2019-08-25T12:05:26.000 |
| 1811 | 2018.1.00211.S | 68 | Understanding nuclear streaming: stellar, atomic and molecular gas kinematics in the inner 100pc: Continuation | In this continuation project, we propose CO kinematic observations of nine nearby active galaxies, chosen for their streaming inflows/outflows and/or bright (IR) molecular disks in our previous 0.5arcsec resolution optical and IR Integral Field observations. These inflows have been observed in ionised and hot molecular gas, with most of them being the tracers of a much more massive gas reservoir of cold molecular gas. We thus propose to obtain the 0.5arcsec spectral-line observations of the nine active galaxies. This besides the ones which have already been observed by us and a handful of others in the ALMA archive will allow us to: a) map the morphology, kinematics and CO distribution on kpc to 50pc scales, for comparison with stellar features (e.g. bars and disks) and kinematics b) search for signatures of molecular gas inflows and outflows and compare the corresponding molecular and ionised gas mass inflow/outflow rates using models of circular rotation and stellar kinematics as references. c) compare mass inflow/outflow rates with nuclear star formation rates and black hole accretion rates and thus constrain the inflow timescales. | Active Galactic Nuclei (AGN)/Quasars (QSO), Spiral galaxies | Active galaxies | 2020-08-06T22:41:16.000 |
| 1812 | 2018.1.00458.S | 16 | Filamentary streamers, conveyor belts and disks in the proto-O star W33A | We propose to follow-up our Cycle 1 (delivered in Cycle 2) observations to fully trace the 3D velocity field of the material accreting onto a newly forming O-star. Our target, W33A, a proto-O-star, is nearby (2.4 kpc) and well studied, already having a rare combination of high resolution observations at near-IR (Gemini-AO- 0.13") and mid-IR (VLTI-MIDI - 0.04") plus our Cycle 1 data (~0.3"). Our ALMA data show a spiral filament feeding material to the central region, where the velocity profile show signs of rotation, suggesting the O-star is forming via a disk. This `disk' appears disrupted by infalling streams (we find at one on 1000au scales - Maud et al. 2017 MNRAS 472 120), fragmentation due to gravitational instability, or interaction with companions. However, we have not yet resolved the disk scales <500au of the system to determine which is the case. Our 3D radiative transfer models (dust & gas) including infall from the outer rotating envelope onto a compact system best matches the binary scenario (disk radii <250au). ALMA will reveal the answer, as it is the only instrument that can zoom in and image the sub-100au scales, allowing us to test massive star formation theories. | High-mass star formation | ISM and star formation | 2020-11-23T21:54:56.000 |
| 1813 | 2013.1.01180.S | 36 | Bulge Asymmetries and Dynamical Evolution (BAaDE) | We have initiated the largest ever survey of red giant SiO masers in the Galactic bulge and inner Galaxy. At the 43 GHz and 86 GHz frequencies of the SiO maser we are not hindered by extinction, and accurate stellar velocities (<1 km/s) and positions are obtained with minimal observing time. The detection of up to ~35,000 red giant SiO maser sources will yield numbers comparable to optical surveys, but with the additional strength of a much more thorough coverage of the highly obscured inner Galaxy. The number of sources will be large enough to trace complex structures and minority populations. The velocity structure of these tracers is to be compared with the kinematic structures seen in gas, complex orbit structure in the bar, or stellar streams resulting from infallen systems. Modeling of the bar and bulge dynamics will be done using the new kinematic information in the inner Galaxy region. Our survey will also yield luminous SiO masers suitable for orbit and parallax determination using VLBI. We are successfully observing with our calibration scheme using the VLA at 43 GHz; we here propose to demonstrate its feasibility with ALMA in the southern sky at 86 GHz. | Spiral galaxies, Galactic centres/nuclei | Local Universe | 2016-03-23T15:59:59.000 |
| 1814 | 2018.1.01001.S | 31 | Into the Mystic: testing the role of ionizing feedback in regulating star formation | Feedback plays a critical but poorly understood role in regulating star formation. Momentum injected by photoionization of fresh material off of cloud surfaces has recently been recognized to play an important role in the evolution and eventual destruction of molecular clouds. This may compress the gas, fostering star formation or drive turbulence, preventing collapse. Theoretical models predict measurable differences in the kinematics and star formation efficiencies in feedback-altered gas. We propose to map the Mystic Mountains, a heavily irradiated complex of dust pillars in the Carina Nebula to measure the kinematics of gas subject to intense stellar feedback. Using the ACA in stand-alone mode, we will measure the distribution of (1) turbulence as a function of distance from the ionization front and (2) protostars forming within the cloud complex. These observations also allow us to constrain pillar formation models and estimate the cloud destruction timescale. Together with observations of the cold gas kinematics in less extreme regions, these data allow us to constrain the role of ionizing feedback in regulating star formation. | Inter-Stellar Medium (ISM)/Molecular clouds, HII regions | ISM and star formation | 2020-02-27T03:03:21.000 |
| 1815 | 2023.1.01515.S | 0 | Detailed observations of the magnetically intertwined Double Helix Nebula in the Galactic Center | Magnetic field plays an important role in the formation and the evolution of molecular clouds. The double helix nebular (DHN) showing the spectacular helical shape in mid-infrared is located ~100 pc above Sgr A* with strong magnetic field along with the helices and suggested to be a magnetized jet launched by the circumnuclear disk (CND). Previous studies with CO(J=1-0, 2-1, 3-2) observations discovered a huge 100 pc molecular tower extended from the CND to the DHN and 1-2 pc elongated 13CO clumps with ~1000 solar masses are stuck perpendicular to the magnetic field lines (Enokiya et al. 2014, Torii et al. 2015). However, there are no direct evidences indicating existence of the jet. Here, we propose HCO+(J=4-3) and CO(J=3-2) observations of the DHN to find direct evidence of shocked gas originated from the jet and to derive the density and temeperature of the molecular clumps formed by the jet. ACA's unprecedented sensitivity and spatial resolution will allow us to study the formation and evolution of the molecular cloud interacted with strong helical magnetized jet and examine the validity of the model for the first time. | Outflows, jets and ionized winds | ISM and star formation | 2025-08-29T20:05:07.000 |
| 1816 | 2015.1.01549.S | 16 | Physical Properties of Possible "Hot" Rings around Protostars | This is the resubmission of the previously approve ALMA Cycle 2 proposal (2013.1.01086.S). We propsoe to use ALMA to investigate physical propoerties of possible "hot" rings we found in our ALMA Cycle 0 observations. In our ALMA cycle 0 observations of young protostars in Taurus, we have detected intriguing SO emission associated with Kepleriand disks surrouding the protostars. The SO emission is rotates in the same manner as the associated C18O envelopes and disks, but their velocity patterns are quite different from those of the envelopes and disks. Our model suggests that the SO emission srizes from hot rings, which may be formed with accretion shocks. In this proposal, we plan to observe multi transitions of the SO lines as well as C18O lines in band 6 and band 7 at 0.2" resolutios to invetigate physical conditions of the SO emiiting regions and to reveal the origin of the SO emission. | Low-mass star formation | ISM and star formation | 2017-10-21T21:29:54.000 |
| 1817 | 2018.1.00876.S | 26 | Inventory of molecular gas in a z~0.7 galaxy group: a test case for environmental star formation regulation in galaxies | How do dense environments, such as groups and clusters, affect star formation regulation and galaxy growth? What are the physical processes responsible for quenching in these structures? This proposal adresses these questions by probing the overall molecular gas content in and around the galaxies living in the COSMOS-Gr30 group at z~0.7. Deep MUSE observations indeed revelead a huge and unexpected ionized gas structure wrapping around 8 of the 45 galaxies located in an over-dense region of this group. This gas has probably been expelled recently from the galaxies due to tidal interactions, stripping, or outflows. The goal of this proposal is to make a census of the overall molecular gas content, i.e. both in the galaxies and in the intra-group medium, available for future star formation in this remarkable structure. To achieve this goal we will map this region in CO(3-2) in order to unveil the extended molecular gas in the intra-group medium, characterize the star formation efficiency in the galaxies and their potential dependence with their location in the structure. These observations will provide crucial tests for star formation regulation models in galaxies. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2020-07-31T12:13:23.000 |
| 1818 | 2023.1.00737.S | 0 | Formation of sulphur allotropes in the Horsehead nebula | The Horsehead nebula is the only ISM source in which S2H has been detected. Therefore, it is the unique testbed to investigate the formation of long sulphur chains (allotropes) in space thus far. It has been proposed that S2H is formed when H2S ice is irradiated by UV photons. High sensitivity mapping with the ACA will allow us to determine the spatial distribution of both molecules, hence providing valuable information on the S2H formation route and its efficiency. The detection of S2H makes this source the most promising object to search for sulphur allotropes. In particular, we will search for S3, the following chemical step to form long sulphur chains. The detection of S3 will be the first one in the ISM and would confirm that long sulphur chains are an important sulphur resevoir in the interstellar medium. The observation of high excitation transitions of other abundant sulphur-bearing species such as 13CS, SO, OCS and SO2 would help to constrain sulphur chemistry in the transition between the photon-dominated region and the molecular cloud. This project is the fundamental stone on which to build our knowledge of the formation of sulphur allotropes in the ISM. | Astrochemistry | ISM and star formation | 2025-11-11T14:21:19.000 |
| 1819 | 2015.1.00657.S | 95 | A spectral line survey of disks | The volatile composition of protoplanetary disks regulates the outcomes of planet formation, including planet bulk properties and chemical habitability. Molecules also provide the only probes of disk kinematics, gas masses, snowlines and other defining disk characteristics. To guide future studies of disks we, as a community, need to know what molecules are present at detectable abundances in disks. We therefore propose to carry out a band 7 spectral line survey toward two young disks around T Tauri star LkCa 15 and Herbig Ae star MWC 480 with an O- and N-rich chemistry respectively. The targeted 45 GHz wide window covers several common disk probes, but the real motivation for the survey is its legacy value as the first unbiased view of disk volatile compositions. To maximize its utility to the disk community we waive all proprietary time and commit to deliver the first fully reduced data products within a month of data arrival. These data will provide the first key steps towards characterizing the organic content of protoplanetary disks across the mass and luminosity regime, directing future ALMA observations beyond our current biased view. | Disks around low-mass stars | Disks and planet formation | 2018-01-10T23:18:50.000 |
| 1820 | 2018.1.00769.S | 24 | Dust Polarization in Young Protostellar Disks: Constraints on Dust Grain Growth | We propose a multi-wavelength dust polarization study of three young protostellar systems in the Ophiuchus molecular cloud. These protostars have large, bright disks that show signatures of dust scattering from previous Cycle 3 polarization observations in Band 6. We will observe the disks at resolutions of ~ 0.25 arcsec (~30 au) in dust polarization in each of Band 7, Band 5, and Band 4. With these observations, we will resolve the polarization structure of each disk over multiple beams. The multiple wavelengths are key to trace different dust grain sizes in the disk and different optical depths. We will use models of dust scattering and grain alignment to characterize the polarization signatures and to constrain the dust grain sizes in these young disks. Grain growth in disks is an important question for disk evolution and planet formation, but it is not well understood. Dust scattering offers an unique opportunity to constrain grain sizes robustly. We will apply this method to a sample of young disks and compare these results to previous techniques. | Low-mass star formation | ISM and star formation | 2024-04-18T18:19:21.000 |
| 1821 | 2013.1.00260.S | 4 | Fragmentation, rotation and infall of a massive disk | Understanding the fragmentation, rotation and infall properties of disks around young high-mass stars remains one of the key questions in star formation research. The unique capabilities of ALMA allow us to probe the physical properties of the gas and dust in the inner envelope and disk region around the central high-mass star. Specifically, using the high-frequency band 9 receivers with 1km baselines at a spatial resolution of ~0.1'', we can for the first time resolve the predicted fragmentation scales on the order of several hundred AU. Simultaneously, we can study the gas infall rates via absorption line studies against the bright submm continuum emission. Therefore, we propose to observe one of the best 10^5 Lsun high-mass disk/outflow candidates G351.77-0.54 at 690GHz in continuum and spectral line emission. Important questions which these observations will address are: What are the fragmentation properties of this massive disk candidate? How large are the infall rates close to the protostar? Are the kinematic properties of the disk-like structure of Keplerian nature or still dominated by a flattened envelope? Are the outflow properties related to those of the accretion disk? | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2016-08-11T11:21:54.000 |
| 1822 | 2023.1.00570.S | 12 | ALMA polarisation as a new probe of supergiant mass loss and dust formation | The origin of high mass-loss events from evolved massive stars remains elusive. Two of the best studied stars, with numerous obvious discrete ejecta, are VY CMa and NML Cyg. Observations have revealed several arcs and clumps with apparent high dust masses ejected over the last few hundred years. ALMA observations have revealed that the most prominent of the dust clumps of VY CMa appears to contain magnetically aligned dust grains. Now what appears to be a similarly massive dust clumps has been found around NML Cyg. Here we propose a multi-band study in order to characterize the properties of the dust in these spectacular ejections and compare them for two of the most prominent supergiant stars. Through obtaining the first polarization SED in the near-stellar environment, our polarisation observations will additionally enable us to determine the dust alignment mechanism and grain size distribution. Only ALMA can provide this important information about the mass-loss of these supernova progenitors. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2025-07-22T14:29:18.000 |
| 1823 | 2017.1.01202.S | 184 | Dust growth in protoplanetary disks in Chamaeleon I | Dust growth in protoplanetary disks is essential to our understanding of planet formation. The maximum grain size in these disks can be probed with the millimeter spectral index of their dust continuum emission. Previous surveys in the young Taurus and Ophiuchus star-forming regions have revealed large grains in their protoplanetary disks, but tentative evidence of a different behavior is found for sources in the older Chamaeleon I region. However, due to its Southern location, only a few objects in this association have enough (sub)mm observations to estimate their spectral indices. We propose to obtain 2mm observations of 53 sources in Chamaeleon I and combine them with pre-existing (sub)mm data to determine their spectral indices, disk dust masses, and radii. These observations will provide the first statistical view of grain growth in this older region, and allow us to study the temporal evolution of this process by comparing Chamaeleon I with younger associations. | Disks around low-mass stars | Disks and planet formation | 2019-04-18T06:27:24.000 |
| 1824 | 2022.1.01566.S | 82 | Dust Temperatures in 70um Dark IRDCs | Dust temperatures and masses are key physical properties of star-forming cores that are generally hard to estimate. Core masses are important to test theories of high-mass star formation as well as to study the universality of the initial mass function (IMF). In a survey of twelve (70 um dark) high-mass clumps, a total of 294 low-to-intermediate mass cores (71% prestellar) have been detected at 220 GHz. Unfortunately, due to the lack of temperature information at 1" scales, the conclusions may be misleading and favoring a particular high-mas star formation theory. In this proposal, we aim to obtain dust temperatures at the size scales traced by ALMA. We will carry out a spectral energy distribution (SED) fitting from 140 to 470 GHz. With both temperatures and masses estimated at 1" resolution (~4,000 AU), we will tackle the following two questions: 1.) Do high-mass prestellar cores exist at the earliest stages of fragmentation? Can we support or rule out any of the two competing theories? 2.) How does the CMF vary after determining temperatures/masses at the observed core scales? | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-08-09T21:09:48.000 |
| 1825 | 2016.1.01154.V | 0 | Imaging the Black Hole Shadow and Jet Launching Region of M87 | The supermassive black hole at the heart of the Virgo A galaxy (M87) powers one of the most well-studied relativistic jets in the sky. Due to its high mass and close proximity, it presents us (along with SgrA* in the Galactic Center) with the opportunity to resolve the shadow cast by the black hole event horizon against the backdrop of surrounding hot plasma. The Event Horizon Telescope (EHT) Consortium has previously used a 1.3mm three-station VLBI array to measure a size of the jet base in M87 to be just 5.5 Schwarzschild radii. With this important confirmation of horizon-scale structure, we propose two tracks of Band 6 VLBI observations with the EHT+ALMA. An ALMA-anchored EHT array can detect the shadow feature, which would provide the strongest evidence for the existence of supermassive black holes and a enable new tests of strong-field GR. Through full polarimetric imaging, the relativistic jet and black hole magnetosphere can be mapped, testing models of jet launch from spinning black holes at the event horizon. In sum, we aim to connect the smallest objects predicted by Einstein's GR to galactic scale outflows that impact large scale structure in the Universe. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-10-21T09:39:23.000 |
| 1826 | 2016.1.00285.S | 77 | The Ionizing Flux in Lensed Galaxies at z~2 | The cosmic star formation rate density varies as a function of cosmological redshift, peaking around z=2-3. Enhanced star formation produces a stronger X-ray flux and larger cosmic ray flux, both of which influence interstellar chemistry through ionization of H and H2. By observing the oxygen bearing ions OH+ and H2O+, we can infer the ionization rate due to particles and photons. ALMA offers the potential to study the ground state transitions of these two molecules in z~2 galaxies, providing the very first opportunity to constrain the total ionizing flux in such objects. We select 4 lensed submillimeter bright galaxies as our targets, all of which show CH+ absorption which traces neutral, mostly atomic gas where OH+ and H2O+ are expected to form. Star formation rates in these galaxies vary from 300 to 1500 M_sun per year, and we expect positive correlation between star formation rate and ionization rate. Deviations from this expectation may hint at the presenece of buried AGN. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-12-14T19:13:45.000 |
| 1827 | 2018.1.00343.S | 6 | Connecting the threads: First mapping of B-fields from 2000 AU to 300 AU in a core with VeLLO | VeLLOs, at the lowest spectrum of substellar masses, are found to be progenitors of very low mass protostars and/or brown-dwarfs which are found to be forming like normal protostars and associated with bipolar outflows. Investigations of B-fields in various low and high mass star-forming regions have been done but never attempted in cores with VeLLOs may be due to their faintness. But these sources are potential candidates to map the inherent cloud B-fields existing on the core scales as momentum flux of outflows from VeLLOs is too low to alter the surrounding B-fields. Therefore, a systematic investigation of B-fields in the cores with VeLLOs at different spatial scales can give us a clue about parent fields geometry. A correlation between B-field orientation, outflow direction and core geometry can help in constraining the available models of low-mass star formation. We are proposing L1521F, the brightest (in 870 um in submm) among other cores with VeLLOs for the polarization observations of dust emission in ALMA band 3. B-field strength will be estimated from Chandrasekhar-Fermi relation which will allow us to understand the energy budget of this core. | Low-mass star formation | ISM and star formation | 2020-07-26T10:41:16.000 |
| 1828 | 2023.1.00360.L | 207 | UNveiling the Initial Conditions of high-mass star-formation (UNIC) | High-mass stars play a key role in shaping the evolution of galaxies, regulating the energetics of the interstellar medium, and the formation of Sun-like systems in dense clusters. ALMA has begun to revolutionize our understanding of the global and local physics involved in this complex process. However, the characterisation of the initial prestellar conditions is left unexplored and provides a major source of uncertainty. The proposed large program ALMA-UNIC will erase this uncertainty, unveiling the initial conditions of prestellar cores in terms of mass distribution, kinematic properties, and ionisation state, a crucial quantity for the dynamics and chemistry of star-forming gas. Previous works showed that oH2D+ is a unique and unambiguous tracer of prestellar conditions, and, furthermore, it allows inferring the cosmic-ray ionisation rate. ALMA-UNIC shall target well-characterised high-mass clumps to generate the most comprehensive and statistically meaningful catalogue of properties of prestellar cores in such regions. Together with cutting-edge MHD numerical simulations of giant molecular clouds, ALMA-UNIC will unveil the initial conditions in the process of star formation. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2025-03-25T18:36:15.000 |
| 1829 | 2013.1.00122.S | 8 | Mapping the Gas in II Zw 40 | We propose to map CO(1-0), CO(3-2), and continuum in the dwarf starburst galaxy IIZw40, which appears to be highly efficient at forming stars. The goals are to determine gas masses, to constrain the star formation efficiency, and to look for evidence of radiative feedback in the form of hot, CO(3-2)-bright gas. Mapping at subarcsecond resolution is critical in the determination of efficiencies and line ratios. | Starbursts, star formation | Active galaxies | 2015-11-13T15:32:27.000 |
| 1830 | 2013.1.01312.S | 6 | Wide-field imaging of dense gas in the nearby barred galaxxy M83 | We propose to make a sensitive mosaic observations of the nearby barred galaxy M83 in HCN (J=1-0). The cycle0 observations of M83 in 12CO (1-0) enabled us to identify ~200 giant molecular clouds (GMCs) over wide range of galactic environments. Comparison with the HII regions indicated that progress of star formation strongly depends on the ratio between two time scales, namely free-fall time and crossing-time. In addition, by adopting a star formation law (SF-law) which relates, SFR, gas mass, and the two time scales, excellent agreement between the observation and the model were obtained for the radial distribution based analyses. Motivated by this finding, we aim to investigate the formation process of dense gas in terms of it's environmental dependence, with the deep HCN observation. Since gas clouds denser than 1e4 cm-3 is known to be the basic unit of star formation, to verify the environmental dependence of SF-law, it is more essential to clarify the formation process of such dense gas. By comparing the deep HCN data with the CO data, and with the already available working hypothesis (time scale dependence of SF), we will address the formation process of dense gas. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2016-06-04T04:31:35.000 |
| 1831 | 2012.1.00225.S | 10 | The Warm/Dense Circumnuclear Disk and Black Hole Mass of Centaurus A | In powerful radio-galaxies the properties of the circumnuclear gas from hundred parsecs down to the accretion disk are hitherto poorly understood. Cen~A is by far the closest giant elliptical and powerful radio galaxy, and is the key to understanding molecular gas properties and the feeding mechanisms in the entire class of powerful radio galaxies. Although it is known that gas with a wide range of temperatures and densities are found to co-exist in the r < 200 pc circumnuclear gas of Cen~A, we still do not have high resolution information of the warm and dense gas. We aim to probe such material via CO(3-2), CO(6-5) with 5 pc resolution, as well as HCO+ and HCN(1-0) with 10 pc resolution, in a mosaic encompassing the inner circumnuclear disk (r<200pc). We will study 1) the distribution and kinematics of such warm and dense molecular gas, especially in an inner gap at r < 80 pc found in our lower resolution CO(2-1) data, 2) probe the physical mechanisms feeding the active galactic nuclei, and 3) obtain a measure of the mass of the supermassive black hole. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2015-10-09T14:42:25.000 |
| 1832 | 2021.2.00062.S | 690 | Time Filler: Feedback Scaling Relations for Gas Infall and Outflows in Massive Starburst Galaxies at Redshifts 1.5-6 | ALMA has recently demonstrated that the ground-state OH+ transitions are an ideal tracer of stellar feedback in massive starburst galaxies back to the first billion years of cosmic time based on detections in ~20 systems at redshifts 2-6. Most detections were obtained with the ACA, revealing a mix of red- and blueshifted absorption, emission, P-Cygni, and inverse P-Cygni line profiles, which are characteristic of gas infall and outflows - revealing the gas supply for the starbursts, and the feedback terminating them. These modest samples revealed relationships between the dust temperature and OH+ optical depth, and the OH+ emission strength and far-IR luminosity/star formation rate, but with substantial scatter. Here, we aim to significantly improve the statistical significance of these relations, and to identify the best cases suitable for high-resolution follow-up with the 12m array by targeting 70 of the brightest lensed starbursts across the sky from the SPT, ACT and Planck surveys, with a particular focus on the undersubscribed LST range. Given the simple selection on apparent brightness, sample completion is not essential, making this an ideal time filler project. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2023-04-04T12:40:11.000 |
| 1833 | 2023.1.01244.V | 0 | The Multi-frequency Horizon-scale View of M87 | This proposal aims to capture the first multi-frequency (at 230 GHz and first ever 260 and 345 GHz) event-horizon-scale resolution, polarized images of the black hole shadow, and the jet at the center of M87. M87* is an active super-massive black hole with powerful relativistic jets. Past observations of M87* by the Event Horizon Telescope Collaboration led to the first total intensity and polarimetry images of a black hole at horizon scales, which shed light on the physics of accretion processes and allowed tight constraints on General Relativity. The proposed high-resolution, multi-frequency images of M87* will enable us to further constrain General Relativity (GR) in the strong gravity regime by testing the achromaticity of the emission ring. We will also be able to understand what mechanism is responsible for jet launching and collimation by investigating the disk-jet connection near the horizon. These objectives will be achieved through joint observations by ALMA and the EHT 2024 extended global array at 230, 260, and 345 GHz frequencies, with three full imaging tracks of 9 hours each, conducted in close succession. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 1834 | 2018.1.00475.S | 6 | CO Polarization Observations of Protoplanetary Disks: Are Magnetic Fields Toroidal in Disks? | Magnetic fields are believed to play a fundamental role in transporting angular momentum in protoplanetary disks. Despite the central prediction of MHD disks that the magnetic fields are predominantly toroidal, it has rarely been tested before. The potential contamination of dust polarization by dust scattering undermines its reliability to trace magnetic fields in disks. Here we propose that the magnetic fields in protoplanetary disks can be detected through the CO polarization arising from the Goldreich-Kylafis effect. Our ALMA CO polarization data in cycle 4 indicate that ALMA is extremely powerful for detecting the Goldreich-Kylafis effect. We have selected two targets with the best possible conditions to detect CO linear polarization with a minimum impact of resonant scattering (i.e. the conversion from linear to circular polarization). The proposed data will (1)provide the first detection of magnetic fields in protoplanetary disks to test weather the magnetic fields are toroidal and (2)resolve the polarization mechanisms of dust emission in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2023-08-16T00:00:00.000 |
| 1835 | 2022.1.00328.S | 10 | Hunting the possible main carrier of Phosphorus in star-forming regions: Phosphine (PH3) | The detection of prebiotic molecules in star-forming regions allows us to better understand how the building blocks of life originate in the interstellar medium. However, among life's key elements (CHNOPS), Phosphorus (P) is the least understood in terms of its ISM chemistry. ALMA observations of P-bearing molecules (PN and PO) towards the AFGL 5142 star-forming region suggest that, besides the role of shocks sputtering dust grains, photochemistry may also play a key role in P-chemistry. However, to confirm this scenario, there is an important missing piece, never detected in star-forming regions: phosphine (PH3). This species is expected to be formed efficiently on the surfaces of grains through hydrogenation of atomic P, and it can desorb thanks to shock-induced grain sputtering. Once in the gas-phase, PH3 can be converted to PO and PN by photochemistry induced by radiation from the star. Therefore, the relative abundance ratios between PH3, PO and PN will constrain the relative importance of shocks and photochemistry in the chemistry of P in star-forming regions. We thus propose to detect PH3 for the first time in a star-forming region. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-01-04T16:24:44.000 |
| 1836 | 2021.1.00219.S | 10 | Unveiling the nature of a huge cold gas reservoir ~18 kpc away from the powerful radio galaxy at z = 5.2 | We propose the [CII] 158 um line and adjacent rest-160 um continuum observations of TN J0924-2201 at z=5.2 using ALMA Band-7, in order to investigate the feeding and feedback processes in one of the most distant powerful radio galaxies known. Specifically, this source is exceptionally gas-rich among HzRGs, with a huge (Mgas~10^11 Msun) and off-center cold molecular gas reservoir detected in CO(1-0) line, indicating that TN J0924 is in a short-lived but crucial gas-rich phase during the growth of the most massive galaxies. Although JVLA CO(1-0) measurement shows the intriguing spatial distribution, its S/N is too low for kinematic studies. Deep ALMA [CII] observation will allow us to study the kinematic properties of the gas reservoir (to see if it is e.g., infalling, outflowing, or rotating) and the physical properties of the circumgalactic medium (using PDR models). Furthermore, we will search for signatures of large-scale shocks via [CII]/CO(1-0) ratios, and assess the star formation rate of the gas reservoir (to see if it associates with significant star formation). TN J0924 is known to reside in a significant overdense region, and we will search for dusty companion galaxies. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-01-05T15:47:45.000 |
| 1837 | 2012.1.00400.S | 3 | Searching for H2D+ in the disk of TW Hya | Most of the mass in a protoplanetary disk is represented by molecular gas concentrated near the midplane, but it is exceedingly difficult to find clear signatures of gas in such locations. Emission lines from deuterated species like H2D+ and D2H+ provide the best - and perhaps only - diagnostics for probing gas in the disk midplane, and thereby learning about the local kinematics and ionization fraction. We propose to search for the ortho-H2D+ 372.421 GHz line toward the well-studied, nearby disk around TW Hya with the "compact" configuration. The proposed observation will allow us to detect ortho-H2D+ fractional abundances down to 3 mJy km/s, more than two order of magnitude below present upper limits. This corresponds to ortho-H2D+ fractional abundance of 3e-13 which is below any published model predictions. A detection will constrain the ionization fraction in the cold disk midplane and help probe the gas kinematics and the viability of MRI-based disk transport physics in this region of the disk. A non-detection will challenge the existing models, helping improve our understanding of accretion flows in the disk midplane. | Disks around low-mass stars | Disks and planet formation | 2016-07-28T14:09:00.000 |
| 1838 | 2017.1.00135.S | 26 | First measurement of "cloud-scale" gas-to-dust ratio of a dwarf galaxy WLM | WLM is one of the-lowest-metallicity, star-forming dwarf galaxies within 1-Mpc distance. In the previous cycle, our ALMA high-resolution and high-sensitivity observations discovered ten small molecular clouds with a typical size of 5 pc in diameter (Rubio et al. 2015). We propose 6-hrs dust-continuum mosaic observations in band 7 toward the clouds to measure the metallicity dependence of "cloud-scale" gas-to-dust ratio (GDR) for the first time. Based on this proposed observation, we investigate (1) the origin of large scatter of galactic-scale GDR in the low-metallicity regime, (2) star formation histories of WLM by comparing with theoretical dust and galaxy models, and (3) metallicity dependence of a ratio of 850um luminosity and ISM mass. The requested sensitivities is determined based on the LABOCA 870um flux and allow us to detect dust continuum with 14-sigma. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2019-12-05T23:28:28.000 |
| 1839 | 2012.1.00456.S | 0 | Mapping Ionizing Photon Rates in the Era of ALMA | We propose for Band-3 (95 GHz) imaging to create ionizing photon rate maps. These observations will showcase ALMA's ability to precisely quantify star formation activity among a physically diverse sample of 9 extragalactic star-forming complexes within galaxies spanning a large range in physical properties (e.g., SFR, metallicity, ISRF, H_2/HI ratios). Each region has a wealth of ancillary data as they have been targeted by the SINGS/KINGFISH mid/far-infrared spectroscopic mapping programs, as well as with the Jansky VLA in the Ka-band (33GHz). By targeting emission at 95 GHz, these observations sample a 'sweet spot' in galaxy radio-to-infrared spectra where contributions from synchrotron, anomalous microwave, and thermal dust emission are minimized with respect to free-free emission arising from newly formed massive stars. Consequently, these new ALMA data will yield an extinction-free measure of the ionzing flux and serve as the zero-point to calibrate other SFR diagnostics available from the rich existing and forthcoming data from the SINGS/KINGFISH legacy programs including, but not limited to, warm/cool dust, PAHs, UV/H-alpha+IR hybrids, [CII]158um (and other mid- and far-infrared fine structure lines). At 2" resolution, and given the range of distances to our sample galaxies, we will map the distributions of ionizing photon rates on spatial scales spanning 90-160pc for comparison with our ancillary dust, H-alpha, Pa-alpha, PAH, atomic and molecular (CO) line maps, providing a better quantitative understanding of the connections between anomalous dust, free-free emission, and gas conditions across the full range of abundances, radiation fields, and ISM physical conditions present in normal galaxies today. The observational setup will also allow for the serendipitous detection of a number of dense molecular gas tracers available within Band-3 (e.g., HCN, HCO+, HNC), potentially enabling studies of the resolved star formation law and astrochemistry. This program is an ideal use of ALMA Cyle1 time as the continuum sensitivity of ALMA in 2012-13 is already powerful enough to make a major scientific advance in the study of extragalactic star formation. | Starbursts, star formation | Active galaxies | 2015-03-31T00:00:00.000 |
| 1840 | 2013.1.01041.S | 3 | Revealing the progenitors of SSCs through shock dissipation in the Antennae merger | We identified a source we believe to be a progenitor of a massive SSC in the Antennae overlap region observing near-IR H2 emission tracing dissipation of its turbulent energy. We propose to look for other pre-cluster clouds (PCCs) with ALMA. To achieve this goal, we propose to map the overlap region in the SiO(5-4) and HNCO(10_(0,10)-9_(0,9)) line emission at an angular resolution of 0.5 arcsec, matched to the size of PCC sources. These molecules are known to be shock tracer in dense gas. The proposed ALMA observations have the combination of sensitivity and spectral and spatial resolution needed to identify several PCC sources and estimate their formation timescale. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2015-11-12T12:48:55.000 |
| 1841 | 2024.1.00201.S | 0 | How low mass protoclusters disperse their natal clouds in Orion A tail. | Low-mass-star formation is the key to understanding the origin of our home, the Sun and Earth, and the origin of terrestrial life. Outside of massive star forming regions, most low mass stars also form in clusters. How these clusters disperse their natal clouds is still unclear, but it is the critical step to understand the initial status of Sun-like stars and planets. We have identified 12 low-mass-star protoclusters in the southern tail of Orion A and found very rich patterns in star-cloud relationship. They uniquely form a complete low-mass-star cluster evolutionary sequence in the same environment to facilitate comparative studies. We propose mosaicking isotopic CO(2-1) lines, SiO and many other line tracers using ACA+TP toward five of them that are in the intermediate state actively shedding their natal clouds. The ALMA data will help us establish the YSO-cloud relationship. Combining them with archival Herschel and Spitzer data and single dish isotopic CO(1-0) line data cubes will allow us to explore the multi-scale dynamical status of these gas clumps, clouds, cores and YSOs and answer the question of how these low mass stars are maturing by expelling their natal clouds. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1842 | 2015.1.00600.S | 28 | Dissecting disks around young B-type stars | The goal of this proposal is to characterize the structure and properties of circumstellar disks around B-type (proto)stars. Our ALMA Cycle 0 observations have demonstrated that disk-mediated accretion is a viable formation route for B-type stars. We could identify (at least) two circumstellar disks around B-type (proto)stars, consistent with Keplerian rotation. However, the angular resolution is not sufficient to discriminate pure Keplerian rotation from other similar rotation curves, and hence derive robust estimates of the stellar mass. We propose to conduct new observations in band 7, with 3 times better angular resolution, 0.15 arcsec. By observing already proven disk tracers (e.g. CH3CN, CH3OH, HC3N) we will (i) resolve the disk structure, determine the rotation curve and investigate variations of temperature and density with radius, (ii) obtain high-fidelity, high-angular images of the disks and their surroundings to search for non-symmetric distributions, (iii) compare observations with predictions from numerical simulations, and (iv) draw some general conclusions on the properties of disks around B-type (proto)stars to compare with low-mass disks. | Disks around high-mass stars | Disks and planet formation | 2017-12-12T15:48:45.000 |
| 1843 | 2024.1.01542.S | 0 | Filament formation and triggered star formation by cloud collision in NGC 1333 | We propose to observe the NGC 1333 molecular cloud with a mosaic mapping and study how cloud-cloud collisions (CCCs) form filaments and induce star formation. CCCs are a promising mechanism for generating molecular filaments by oblique shock wave with magnetic fields as shown by MHD simulations. We will observe filaments with different column densities and star formation activity in the NGC 1333 cloud in CO isotopes and some dense gas tracers at 0.01 pc resolution, which is sufficient to resolve the filament substructures. Also by using shock tracers such as SiO and CH3OH, the presence of collision is to be confirmed, and the morphological and velocity structures of observed filaments are compared with the theoretical oblique shock model. We will classify the filaments according to their line masses and divide them into evolutionary stages based on their star formation activity. We will investigate how CCCs enhance the mass accretion onto the filaments and increase their line masses above the critical value for gravitational instability. This is a resubmission of our ongoing program. Half of the TP-array data have been taken, but none of the 7m array so far. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1844 | 2016.1.01018.S | 109 | The Masses, Diversity, and Evolution of Circum-Planetary Disks | Circum-planetary disks are natural outcomes of giant planet formation but are observationally difficult to study. Fortunately, a handful of widely separated (>100 AU) planetary-mass companions have recently been discovered around young stars with adaptive optics imaging, enabling the first investigations of the formation and environments of young giant planets. Early ALMA results point to a diverse range of masses and evolutionary states for these subdisks. Here we propose ALMA 880 micron continuum and CO observations of six young planets that themselves harbor disks to assess the diversity, demographics, and evolution of subdisks as a population. By increasing the sample by a factor of three we will also constrain the formation of these objects by distinguishing planet-planet scattering from disk instability or cloud fragmentation. Finally, we will measure the dynamical mass of the candidate protoplanet FW Tau b through CO 3-2 line emission. If its low mass (5-15 Mjup) is confirmed, this will be the first mass measurement for a directly imaged planet, indicating that the same accretion and outflow processes that occur in young stars also operate in the planetary regime. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2019-05-31T15:11:47.000 |
| 1845 | 2019.1.00059.S | 20 | Observing in real time the onset of outflow collimation in a massive protostar | Over 20 yr we have seen in “real time” that the expanding H2O maser shell found around the radio continuum emission of the massive protostar W75N VLA2, as well as the continuum source itself have evolved from an almost isotropic outflow into a jet (phenomenon not seen before in any protostar). We interpret this unique behavior in terms of an episodic, short-lived (tens of years), originally isotropic ionized wind whose morphology evolves as it moves within a toroidal density stratification. Through ALMA Band 6 continuum observations we will test this scenario by detecting the expected dust torus around VLA2. In addition, through molecular line observations we also expect to find collimated outflows associated with VLA2 and VLA1 (a radio jet separated from VLA 2 by 0.7”), parallel to each other and to the magnetic field orientation we found in the region. If such a parallel orientation of the outflows is observed, this would strongly indicate that the magnetic field plays a key role in the ejection and evolution of the outflows of these massive protostars. This opens a new, exciting window of opportunity to study how basic ingredients of massive star formation evolve in “real time". | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2023-08-11T22:31:38.000 |
| 1846 | 2024.1.00970.S | 0 | Mapping the Spatial Distribution of Complex Molecules in L1544 with ALMA Band 1 | Low-mass stars like our Sun form in prestellar cores, which are cold (10 K) and dense (> 10^5 cm^-3) collections of gas and dust within molecular clouds. A significant amount of the chemical inventory around planet forming disks and young stars is believed to be inherited from the prestellar core phase. Therefore, it is important to understand the formation of interstellar complex organic molecules (or COMs) in prestellar cores to answer larger questions regarding the origins of life. We propose to show-case ALMA Band 1 capabilities with a 26-hour 12m program that will map the evolved core L1544 in a 2' x 2' region (3 total pointings) down to 2.6 mJy rms at high spectral (~0.1 km/s) and spatial (~ 10'', 1700 AU) resolution. We will probe for the first time the 2D spatial distribution of COMs larger than methanol in a cold prestellar core, i.e., acetaldehyde, CH3CHO, and methylcyanoacetylene, CH3C3N. Only ALMA Band 1 can probe, relatively quickly, the spatial distribution of highly complex molecules at high sensitivity at core-scale resolution. From these observations quantitative constraints will be placed on COM formation mechanisms, still largely debated for cold (10 K) cores. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 3000-01-01T00:00:00.000 |
| 1847 | 2018.1.00541.S | 248 | Why is star formation boosted from the inside out in low z starburst galaxies? | High spatial resolution maps of stars and gas in nearby galaxies provide vital insight into how stars are form on kpc (and below) scales. Such local studies, such as HERACLES, PAWS and EMPIRE, have shown that star formation depends sensitively on environment, as well as the raw gas reservoir available as fuel. However, these local samples are limited by statistics, and hence do not sample galaxies at the extremes of star formation. We propose to study the interplay between gas and star formation in a sample of low-z starbursts, selected from the MaNGA IFU survey. Although rare in the low redshift universe, local starbursts represent analogs to star formation at high-z, where galaxies were more gas-rich and formed stars at much higher rates than obseved today. We have recently shown (Ellison et al. 2018) that these low-z starbursts are centrally concentrated, building stellar mass from the inside-out. By combining the kpc-scale MaNGA SFR maps with CO maps obtained on the same spatial scale, we will distinguish whether the central starbursts occur due to a simple abundance of molecular gas, or whether they additionally exhibit elevated star formation efficiencies. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2020-02-27T00:02:53.000 |
| 1848 | 2017.1.00931.S | 63 | From Beginning to End -- Star Formation and Molecular Cloud Evolution in the Small Magellanic Cloud | We propose 12CO, 13CO, and C18O (2-1) Band 6 observations of two molecular clouds in the SW Bar of the Small Magellanic Cloud (SMC) to explore how the properties of molecular gas change as a cloud evolves and forms stars. By directly observing low-mass pre-main sequence (PMS) stars via Hubble Space Telescope (HST) imaging, we can trace the history of star formation in these clouds over the last ~20 Myr. ALMA molecular gas maps at 1" (0.3 pc) angular resolution will reveal the detailed distribution of gas with respect to the stars, and allow us to investigate the physical state of the gas before and after the onset of star formation. We target two clouds at opposite extremes of cloud evolution (judged from the ratio of PMS stars to CO emission from existing APEX measurements): pre-star formation conditions in the B1-2-E cloud, and on-going massive star formation in the SWBar Filament. The combination of ALMA and HST observations let us trace the full life cycle of SF, from natal molecular gas to newly formed stars, allowing us to simultaneously characterize cloud star formation histories, gas conditions, and the sources and effects of stellar feedback. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2019-12-21T00:00:00.000 |
| 1849 | 2024.1.00031.S | 0 | Ultimate sampling of the global dust emission in a normal sub-L* galaxy at z=6 | We ask for Band 9 observations to detect the dust continuum of one of the brightest lensed [CII] emitters known at z=6.07. We will combine these observations with 7 independent ALMA points to map the dust SED from ~60 to 370um rest-frame plus Herschel upper limits, thus obtaining continuous coverage of both the peak and the Rayleigh-Jeans tail of the emission. This will allow us to derive a robust temperature, IR luminosity, and obscured SFR, while shrinking the dust mass uncertainties by a further factor of 3-5x. This remarkable source is also covered by JWST/NIRCam + NIRSpec IFU, HST, and VLT/MUSE observations, giving us access to the stellar and ionized gas phases. Together with ALMA coverage of several FIR and molecular lines, the requested observations will provide a complete set of observables of both warm and cold phases of the gaseous and dusty ISM for a normal, sub-L* galaxy at the end of reionization. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 3000-01-01T00:00:00.000 |
| 1850 | 2023.1.00487.S | 0 | Vertical structure and planetary system dynamics | The vertical structure of debris disks encodes valuable information about the dynamical state of planetary systems between 10Myr and 1Gyr. Resolving vertical structure at millimeter wavelengths provides insight into the prevalence of Uranus and Neptune analogues and the total mass reservoir of both dust and gas, while resolving the vertical structure at two widely separated wavelengths also probes the physics of the collisional cascade that generates the observed dust, including the tensile strengths of the bodies. Here we propose to leverage archival data, including ongoing high-resolution Band 7 observations from the ARKS large program, to complete a sample of the brightest, well characterized, nearly edge-on disks debris disks with well-resolved (at least 2 beams per FWHM) vertical structure: two gas-bearing disks and two gas-poor disks will be observed at two widely separated frequencies, and compared with existing scattered light observations from GPI, SPHERE, HST, and JWST. The proposed observations will expand the number of systems with dual-frequency resolved observations from one to five, enabling a comparison of properties across spectral type and age. | Debris disks | Disks and planet formation | 2025-10-03T00:12:37.000 |
| 1851 | 2018.1.00538.S | 442 | ALMA-BASS: CND-scale molecular gas survey toward nearby luminous AGNs selected with the Swift-BAT hard X-ray survey | We propose a 100 pc resolution CO(2-1) survey toward the circumnuclear disk (CND)-scale of 33 nearby and luminous AGNs, drawn from the Swift-BAT X-ray catalog, as a part of our extensive multi-wavelengths follow-up studies (The BAT AGN Spectroscopic Survey = BASS). With a common equivalent sensitivity for H2 mass (10^5 Msun), we will address the following questions. (1) CND-scale gas mass: Is the AGN activity more strongly related to the CND-scale gas mass, rather than the galaxy-scale one measured with APEX (i.e., are the CNDs the reservoir of gas fueling)? (2) Molecular outflows: We aim to detect outflows and measure outflow rates. By using the CND-scale gas mass and star formation rate derived by us, we will estimate the CND-scale gas depletion time scale. Is it consistent with the AGN duty-cycle? (3) AGN feeding: As we will measure the size of the line/continuum emitting regions, we can estimate gas mass surface density. Does AGN accretion rate depend on it, as expected in accretion models? As our sample comprises the least-biased luminous AGNs in the local universe, this CO(2-1) survey has great legacy value to motivate subsequent higher resolution follow-up studies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2019-11-06T08:06:30.000 |
| 1852 | 2019.1.00147.S | 198 | CO(7-6) and [CI] survey in z>6 quasars | Quasar hosts at z>6 (age of the universe: <1 Gyr) experience intense star formation (>100 Msun/yr) and rapid gas accretion (>10 Msun/yr) onto their central massive black hole. Over the last few years, ~50 quasars at z>6 have been observed in their [CII] and underlying dust continuum emission. This enabled measurements of their precise redshifts, star formation rates, host dynamics, and galactic environment. Here we propose to further investigate the cold ISM in z>6 quasar hosts by targeting the carbon monoxide CO(7-6) and atomic carbon [CI]2-1 lines, which are conveniently covered in a single 3mm frequency setting at z>6.1. This will allow us to estimate the mass in dust, molecular and neutral gas, and the gas-to-dust ratio. Furthermore, the combination of these lines with the (already secured) [CII] emission enables diagnostics of the density of the cold ISM and of the mechanism responsible for the gas excitation (nuclear activity vs star formation). This filler project will triple the number of z>6 quasars with available data on [CI], CO(7-6), and [CII], thus providing us with a statistical base for unraveling the early evolution of massive galaxies at cosmic dawn. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-02-12T05:21:02.000 |
| 1853 | 2017.1.00766.S | 260 | From the main sequence to the red cloud: linking the molecular cloud lifecycle to galaxy evolution | The molecular cloud lifecycle, the efficiency of star formation and the coupling of feedback to the ISM depend both on local and global conditions, and strongly affect the global evolution of galaxies, from the main sequence to the red cloud. Mapping the molecular gas on the cloud scale across a broad range of environments is a key step to measure these quantities and understand how the local physical processes contribute to regulating star-formation and feedback in galaxies on large scales. We propose to apply the high sensitivity and high angular resolution of ALMA to map the molecular gas disc down to cloud scales in a sample of early-type galaxies, which are in (or have completed) the transition from the main sequence to the red cloud, and study the interplay between small-scale physics and galactic structure. Combined with our previous results on ~20 star-forming main sequence galaxies, we will thus cover the complete evolutionary track of galaxies. This will provide strong constraints on whether galaxy quenching is driven by a cloud-scale inefficiency of star formation or by galaxy-scale processes. | Early-type galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2020-06-22T00:00:00.000 |
| 1854 | 2018.A.00030.S | 9 | First characterisation of a multi-planetary system at the stage of formation | Many questions regarding planet formation are still open, in particular how material is accreted from the protoplanetary disk onto the forming planet through its circumplanetary disk (CPD). PDS 70 is a unique source to investigate such processes as it hosts two planetary companions within an inner cavity. These sources, PDS 70b and c, were robustly detected with SPHERE (infrared) and MUSE (Halpha). The analysis of ALMA Band 7 observations, at an angular resolution of 70 mas, indicates continuum emission at the location of the planets and represents the very first detection of a CPD. However, higher resolution observations at 30mas are required to confirm the presence of these two CPD and spatially resolve the CPD around PDS 70c from the edge of the continuum ring. In addition, substructure within the dust ring and a peak of CO emission offset from the bulk Keplerian profile strongly suggests the presence of a third companion of the disk. The requested observations would also allow for the characterization of substructure within the dust ring, required to confirm the presence of a third companion. The high impact nature of these results clearly warrants immediate DDT observations. | Exo-planets | Disks and planet formation | 2020-12-31T00:00:00.000 |
| 1855 | 2023.1.00341.S | 0 | Shocked Molecular Clouds Associated with the Historical Supernova Remnant RCW 86 | Investigating supernova feedback is essential in understanding both star formation and the evolution of the ISM. We propose multi-CO line observations of shock-interacting clouds in the historical supernova remnant RCW 86 to better understand the heating process of shocked gas and its relation to the shock-ionized plasma. Most recently, we have revealed the shock-excited clouds in RCW 86 using 12CO(J=3-2) data taken by a single-dish telescope. Through an X-ray spectroscopic analysis, we found a relatively high plasma temperature toward the shocked clouds, suggesting a strong relation between them. However, we could not estimate the kinematic temperature Tkin and H2 density n(H2) of shocked clouds and compare them with plasma parameters quantitatively due to a lack of other CO lines with a sufficient angular resolution. The proposed ALMA ACA observations of 12CO and 13CO(J=1-0) at a resolution of 13 arcseconds (~0.16 pc, compatible with that of the XMM-Newton X-ray data) will derive Tkin and n(H2) under the non-LTE assumption and compare them with physical properties of X-ray hot plasma for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-01-23T13:19:11.000 |
| 1856 | 2019.1.00512.S | 18 | Chemistry in extremely FUV illuminated protoplanetary disks | The composition of planets is set by the chemical inventory of the protoplanetary disk where they form. Up to now, studies have focused on characterizing the molecular inventory of disks around isolated stars. However, most Solar-type stars form in clusters where the radiation field can be enhanced by several orders of magnitude relative to isolated stars. Theoretical studies predict that the chemistry of heavily irradiated disks should be affected, but currently we have no observational constraints to test these predictions. To address this unknown, we propose to carry-out a modest survey of the molecular inventory in four disks in the massive star forming region of Orion, the closest region that has such a high-UV radiation field (G0~10^5). The disk sample span a range of distances from the ionizing stars in the cluster to explore the effect of proximity to ionizing stars. We will target molecular tracers that have been used successfully to characterize the chemistry in isolated disks: CO isotopologues, CN, HCN, DCN, C2H, C3H2, CS, and H2CO. This will allow a direct comparison to assess what is the impact of strong FUV radiation on the disk chemistry. | Disks around low-mass stars | Disks and planet formation | 2022-11-18T07:23:43.000 |
| 1857 | 2017.1.00551.S | 12 | Multiplicity of brown dwarfs at the earliest evolutionary stages | The multiplicity properties of brown dwarfs (BDs) have been studied in the field and in star forming regions: BDs are normally found in tight binaries (sep < 20 au) with mass ratii close to 1. Are they born with these properties or/and are they the result of their evolution? To shed light on this topic, here we propose band 7 ALMA observations of 5 Class 0 proto-BDs, that is, BDs at the earliest stages of their evolution when they are still deeply embedded in their parental cloud. The main goal is to search for companions and compare the proto-BD binary properties with those reported in more evolved BDs. Note that non-detections will also help to put constraints on the binary frequency, separation range and mass ratio. The results will be compared with predictions from different models of BD formation, to check which of them can reproduce the observed properties. | Low-mass star formation | ISM and star formation | 2018-12-19T13:17:45.000 |
| 1858 | 2023.1.00703.S | 0 | Revealing the Outgassing Mechanisms of Mega-Comet C/2014 UN271: Spectrally Resolved CO and Synergy with JWST | We propose ALMA observations to perform spectrally resolved measurements of CO in "mega-comet" C/2014 UN271. UN271 is the most massive and distantly active comet ever discovered, with a nucleus size of 140 km and activity beginning at heliocentric distances (rH) ~ 28 au. ALMA and HST observations have confirmed the large nucleus size and indicated a huge dust production rate (10^3 kg/s), and JWST DDT observations detected CO and CO2 at rH = 18 au. We will reveal the kinematics of CO in UN271 for the first time, and test whether there are extended CO sources. We will simultaneously measure the continuum flux of mm-sized dust grains, thereby calculating the dust production rate and calculating the dust-to-gas ratio. These observations will yield fundamental insights into the mechanisms driving activity in UN271, shedding light on its formation history and the composition of small Kuiper Belt objects, which are too distant to observe significant outgassing and whose compositions have hence remained elusive. | Solar system - Comets | Solar system | 2025-03-20T00:00:00.000 |
| 1859 | 2017.1.01462.S | 312 | Unbiased Chemical Survey of Protostellar Sources in Perseus | It is well known that low-mass protostellar cores show significant chemical diversity. One distinct case is hot corino chemistry characterized by rich saturated complex organic molecules, while the other distinct case is warm carbon chain chemistry (WCCC) characterized by rich carbon-chain molecules. However, the number of sources definitively classified into them are limited, and the statistics is apparently poor. We here propose to conduct an unbiased survey of chemical composition toward 37 Class 0/I protostars in the Perseus molecular cloud complex. Our recent observations toward these target sources with the single-dish telescopes shows clear chemical diversity, where many intermediate sources are found between the two distinct cases. We are going to confirm this result with ALMA to establish chemical diversity in the 100 AU scale. A relative occurrence of each category (hot corino chemistry, WCCC, or intermediate) as well as preferential association of the sources in each category with a specific part of the cloud complex will give us an important clue to understanding the origin of the chemical diversity in terms of evolutionary history and/or environmental effects. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-10-27T10:47:16.000 |
| 1860 | 2018.A.00050.T | 40 | Sgr A* Coordinated observations with Spitzer, Chandra, NuSTAR | ALMA observatory program aiming at monitoring the submm flux of Sgr A* in coordination with space observatories. The windows of observation are selected in order to maximize the ALMA coverage in the programmed space observatory epochs from https://www.cfa.harvard.edu/irac/gc/ | Galactic centres/nuclei | Active galaxies | 2019-08-14T00:00:00.000 |
| 1861 | 2016.1.00391.S | 13 | Direct Detection of Infall in a Protostellar System | Gravitational collapse is the foundation of modern star formation models. Although the model has been widely accepted, direct and unambiguous observational evidence has been elusive. A red-shifted absorption by a molecular line against the protostellar continuum emission provides unambiguous evidence of infall. The unprecedented resolution and sensitivity of ALMA allowed detection of this feature toward B335 (Evans et al. 2015), demonstrating the feasibility of this method. We propose to search for the infall signature in BHR71, an isolated Class 0 protostar similar to B335, but with 10 times the luminosity and the mass infall rate. We have extensive observations on BHR71, where we find hints of infall, as well as a 3-D dust radiative transfer model. Therefore, BHR71 is an excellent target for comparison with B335, but the resolving power of ALMA is necessary to detect the signature of infall. | Low-mass star formation | ISM and star formation | 2018-04-03T16:49:18.000 |
| 1862 | 2015.1.01082.S | 45 | ALMA imaging of the Orion Bar: Density structures and chemical stratification in PDRs | We propose to study the small-scale (a few hundred AU!) density structure of the Orion Bar PDR. We would like to investigate the nature of the inhomogeneities and instabilities revealed by our ALMA (Cycle 1) CO 3-2 and HCO+ 4-3 images of this prototypical UV-irradiated cloud. We propose to carry out a detailed analysis of the penetration of the UV-radiation throughout these structures. Our goal is to disentangle the respective roles of temperature and density enhancement and of non-thermal processes on molecule formation. These are key questions controlling the life-time of molecular clouds against photoevaporation and the applicability of PDR molecular diagnostics respectively. We propose to image the very high critical density HCN 4-3 line and to follow the CN 3-2/HCN 4-3 intensity ratio, a sensitive tracer of the UV field attenuation. We also propose to spatially resolve the reactive ion CO+ emission. Owing to its specific temperature-dependent formation pathway from OH and C+ (both mapped by us with Herschel) we will be able to separate the thermal and non-thermal (reactions with UV-pumped vibrationally-excited H2 in particular) contributions to the PDR chemistry. | Intermediate-mass star formation | ISM and star formation | 2020-10-12T00:00:00.000 |
| 1863 | 2018.1.00478.S | 662 | On the nature of 3mm-selected sources: the highest redshift dusty star-forming galaxies? | At z>4, the largest submm/mm surveys are only sensitive to the most extreme dusty star-forming galaxies (SFR>1000 M_sun/yr). Less extreme sources can be detected in the deepest single-dish telescope surveys, however, the identified population of DSFGs are overwhelmed by the more abundant low-z population (not to mention their large positional uncertainties). Recent deep pencil-beam surveys from ALMA have also failed to detect high-z sources. We have analyzed, for the first time, the potential of 3mm observations to detect high-z DSFGs. This wavelength naturally filters out z<2 galaxies due to a very negative K-correction. We find 14 serendipitously-detected 3mm sources within ~160 sq. arcmin of ALMA archival observations. Three of them already have spectroscopic redshifts (z=2.5-4.5), which confirms their high-z nature. Here, we request 19h of observations (including overheads) to conduct a blind redshift survey for the remaining sources using an optimized band 3 + band 4 spectral setup. This work will reveal the nature of 3mm galaxies and their contribution to the cosmic star formation rate density, and will costrain the infrared galaxy luminosity function at high-z. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2020-01-18T01:04:02.000 |
| 1864 | 2021.2.00137.S | 11 | Properties of the most extended molecular halo ever observed | Cycle 7 ACA low-resolution (~80 kpc) observations led to the unprecedented discovery of a giant CO(3-2)-line emitting molecular gas halo extending out to r=200 kpc from cid_346, an X-ray selected quasar at z~2 ongoing an explosive feedback phase with energetics outflows. The ACA-detected halo has a CO(3-2) flux that is 14 times larger than that measured by ALMA in the same source on ISM scales (r<8 kpc), it has a broader velocity distribution (FWHM ~ 1000 km/s), and it is not associated with a known optical-infrared-submillimeter overdensity of galaxies at the same redshift. The proposed observations aim at measuring with higher accuracy the molecular CGM mass, and understanding its composition (outflows, inflows, hidden companions, etc) by combining the information from multiple molecular gas tracers and spectrally resolving its kinematics on CGM scales. Here we propose deeper, multi-tracer (CO3-2, [CI]1-0, [CI]2-1, CO7-6) follow up observations of this source. | Outflows, jets, feedback | Active galaxies | 2023-12-21T17:53:58.000 |
| 1865 | 2016.1.00925.T | 326 | Constraining the Jet Properties of Transient X-ray Binaries | Since active galactic nuclei (AGN) likely play a major role in galaxy formation, it is essential that we understand the processes of accretion onto compact objects and accretion-fed outflows, like relativistic jets. Black hole X-ray binaries (BHXBs) provide ideal laboratories for probing jet phenomena as they evolve on timescales of days to months (unlike AGN that evolve over millions of years). Broad-band spectral measurements of this jet emission in BHXBs allow us to constrain the physical conditions in the jet, which can then be coupled to the properties of the accretion flow, probing the mechanism that governs how jets are launched and quenched. The mm regime bridges a crucial gap between radio and IR frequencies in the broad-band jet spectrum. We propose targeting the next outbursting BHXB (f_6GHz> 1mJy) with 3 epochs of ALMA target of opportunity observations to measure the dynamic mm behaviour in a BHXB. Coupled with our exceptional multi-wavlength coverage, these ALMA observations allow us to accurately measure the mm flux density & spectral index, and constrain the dynamic broad-band spectral energy distribution in BHXBs with unparalleled accuracy. | Black holes, Transients | Stars and stellar evolution | 2018-11-14T23:24:23.000 |
| 1866 | 2023.1.01143.L | 0 | The Large 12P COMA survey (COmetary Molecules with ALMA) | Cometary observations with ALMA can elucidate the origin and composition of our Solar System's most ancient materials, while providing major advances in our understanding of coma physics and chemistry. This large program aims to leverage the vast collecting area of ALMA to perform spectral imaging of 12P (Pons-Brooks), one of the brightest comets of our era. The unprecedented sensitivity and high angular resolution of these data would provide (1) the first ever spatial maps for multiple gases, from which their coma and nucleus sources can be quantified; (2) isotopic ratios in key cosmogonic indicators (D/H, 14N/15N), to shed light on the physical/chemical history of primitive, planet-forming materials, including D/H in molecules not previously observed in comets; (3) new insights into interstellar/protoplanetary disk ice compositions; and (4) likely detections of new cometary molecules. Comprehensive mm/sub-mm mapping of 26 different molecules in this rare apparition of a bright, Halley-type comet can only be performed using ALMA, and will provide a valuable legacy dataset for the interstellar, protoplanetary disk and cometary science communities. | Solar system - Comets | Solar system | 2025-05-28T20:01:59.000 |
| 1867 | 2016.1.01475.S | 66 | Are Class 0 molecular jets really molecular? ALMA insight into the origin of protostellar jets | We propose to exploit the new capabilities reached by ALMA in Cycle 4 to image for the first time a protostellar molecular jet (HH212) at 0.12 resolution, ie. comparable to HST images of Class 2 atomic jets, with sensitivity to extended emission up to 4. We will observe a range of bright jet tracers in Band 7 (SO, SiO, CO, SO2) with differing critical densities and chemical behaviors. This unprecedented dataset will allow us to carry out, for the first time, several decisive tests of the origin of molecules in protostellar jets, namely: whether they are ejected from the dusty disk surface or whether they could reform behind shocks in dust-free winds; this will bring key constraints on the long-lasting issue of the launch region of jets from accreting stars. The comparison of these data with models will be the central subject of the Ph.D. thesis of B. Tabone. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-12-06T14:34:38.000 |
| 1868 | 2019.1.01768.S | 9 | Probing the magnetic field towards a massive dense core in the potential well of a hub-filament system | There is a growing evidence of the role of hub-filament systems in the formation of high-mass stars. These systems are believed to provide the fast accretion rates and the internal turbulent support needed for the massive dense prestellar cores to accrete a large fraction of their mass before the feedback from the central protostars disperse the surrounding material. However, the formation and evolution of these systems at the early prestellar phase are still unexplored. Especially the strength of the magnetic field in dense cores (densities >10^7cm-3) is not constrained observationally. We propose ALMA (cycle 7) 3mm full polarization observations to measure the Zeeman splitting of the hyperfine transitions of the CN(1-0) to derive the magnetic field intensity of one of the most extreme massive dense prestellar core sitting in the centre of a hub threaded by multiple filaments. With these observations we seek to measure the Zeeman effect to derive the magnetic field strength and study the role of the magnetic field and its interplay with turbulence and gravity in the formation and evolution of such massive, cold, and dense prestellar cores, the progenitors of high-mass stars. | High-mass star formation | ISM and star formation | 2024-05-14T16:53:57.000 |
| 1869 | 2015.1.01516.S | 19 | Mysterious millimeter excess of radio continuum spectrum in the merging Seyfert galaxy NGC 985 with double nucleus | Aim: We propose to confirm the presence of millimeter excess, which was inferred from the radio continuum up to 43 GHz toward the Seyfert nucleus in the undergoing merger galaxy NGC 985 with double nucleus, by using ALMA at ~100 GHz. Scientific Impact: The possible physical processes are synchrotron radiation from accretion disk's corona including nonthermal particles or extremely frustrated radio jets in highly dense environment around the merging nuclei. Any of them is observationally the first case, if we detect it successfully. Why do we need ALMA?: On the basis of our previous VLA observations at 8--43 GHz, the millimeter excess is expected to be ~2 mJy, which was negative detection in our observation using the Nobeyama Millimeter Array at 100 GHz. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-04-09T00:03:15.000 |
| 1870 | 2019.1.01032.T | 87 | A Precision Test of Gamma-ray Burst Afterglow Models | GRBs are powered by extreme compact objects (newly-formed black holes or magnetars) that eject matter at ultra-relativistic velocities (Lorentz factor >>100). This makes them ideal laboratories to study radiation processes in extreme conditions. The fast-reacting GRB satellite Swift has been in orbit for almost 15 years, but only in the last few years have radio and submillimeter facilities obtained sufficient sensitivity and response time to test afterglow models in detail. Those tests are fundamental and address key difficulties in understanding the physics of cosmic particle-accelerators. We propose a joint ALMA+JCMT+NOEMA+GMRT effort to study one GRB afterglow this cycle from early (hours) to late times (months) across the radio spectrum. With ALMA, we propose to secure 5 epochs at 95 and 340 GHz spanning three months following the GRB. We will complement these observations with X-ray and optical data to model the broadband afterglow in detail, allowing us to precisely test models and characterise non-standard radiation components. | Gamma Ray Bursts (GRB) | Cosmology | 2022-06-22T09:31:58.000 |
| 1871 | 2021.1.00116.S | 46 | Clarifying CI distribution in molecular cloud by absorption observation toward compact quasars behind the Milky Way | We propose to perform [CI] absorption observations toward two compact quasars, J1851+0035 and J1935+2031, behind the Milky Way (MW). High-resolution ALMA beam toward QSOs can reveal the internal structure of a molecular cloud in the MW at a scale of ~100AU. Many observations found that [CI] distributions are similar to those of CO against the prediction by the classical photo-dissociation region (PDR) model. A model that molecular cloud consists of many clumps so as UV radiation can penetrate into the cloud, called clumpy PDR model, is suggested, although being unproven. Recent ALMA observations revealed that molecular clouds traced by CO are composed of many small clumpy structures. Investigating the consistency of the spectral features between [CI] and CO and PDR probes, we will reveal [CI] structure and UV effect within a molecular cloud so as to verify the clumpy PDR model. Unless we found the consistency, the effect of turbulence or chemical evolution should be considered. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2022-11-20T06:31:18.000 |
| 1872 | 2024.1.00028.S | 0 | Beholding Massive Star Cluster Formation and Evolution with the "Evil Eye" | We aim to build a complete timeline of massive star cluster assembly via a mass-limited survey of the youngest massive clusters (``proto-YMCs'') in the Evil Eye Galaxy (M64), the nearest post-merger starburst system (d = 4.4 Mpc). We will observe free-free emission, thermal dust emission, and dense molecular gas tracers in Band 3 and 7 at ~0.1" = 2 pc resolution, matching that of existing HST imaging and forthcoming JWST observations. The combined dataset will allow us to: (1) identify ``proto-YMCs'' as progenitors of the more evolved clusters visible to JWST and HST, (2) derive the time span of the starless, embedded, and exposed phases of cluster formation based on source number statistics, (3) quantify feedback-driven gas expulsion during cluster assembly with two independent methods, and (4) put forming clusters in the context of large-scale gas filaments and converging flows. This will be the first joint ALMA-JWST-HST census of YMCs in all evolutionary stages across an entire starburst galaxy, where observational constraints on YMC mass, evolutionary timeline, and feedback strength provide the best stress tests for theories of cluster formation. | Starbursts, star formation | Active galaxies | 2025-10-31T02:53:51.000 |
| 1873 | 2016.1.00924.S | 100 | Understanding the Formation of Globular Clusters | In previous ALMA observations, we identified an extraordinary molecular cloud with the properties required to form a globular cluster (including size and mass). The lack of associated thermal radio emission indicates that star formation has not yet altered the environment, and places this cloud at a very early stage of evolution. Given the extremely short lifetime expected for this phase of cluster evolution (< 1Myr), we expect clouds such as this to be exceptionally rare, which is reflected by the fact that this is the only such cloud identified in the ALMA Antennae data set. Thus, we have the opportunity to determine the physical conditions in a proto-globular cluster molecular cloud -- before these conditions have been disrupted by star formation -- for the first time. With this proposal we seek to determine the resolved physical conditions in this cloud, constraining possible formation mechanisms. We propose ~0.1" (=10 pc, 5x better than the Cycle 0 observations) imaging of this singular molecular cloud in 12CO(2-1), 12CO(3-2), 13CO(2-1) to determine its basic physical properties including mass, size, linewidth, and temperature. | Starbursts, star formation | Active galaxies | 2018-02-02T17:40:52.000 |
| 1874 | 2018.1.01817.S | 374 | Following the evolution of the most luminous AGN: the epoch of z=2-3.5 | We propose to obtain sensitive dust continuum flux measurements for a well defined sample containing the most luminous quasars at z=2.0-3.5, for which we have Herschel detections (18 sources) or upper limits (43 sources). The ALMA observations will allow us to study the relation between the nuclear luminosities (L_AGN, already obtained from existing optical spectra) and the luminosity associated to the star formation in the host galaxy (L_SF). The ALMA observations will also allow us to determine the presence of dust enshrouded companions and therefore systematically determine any possible relation between L_AGN, L_SF, the presence of nearby sources, and the impact of feedback acting at the highest AGN luminosities. Future ALMA observations will allow us to further constrain the dynamical mass of the host galaxies using spectral information and determine whether the observed companions are physically associated to the quasars. Using NIR spectroscopy we will obtain accurate BH masses and accretion rates. The end result will be the most complete and statistically significant census of star forming activity among luminous quasars at the epoch of peak black hole activity. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2020-08-30T15:44:51.000 |
| 1875 | 2017.1.00224.S | 25 | Chemical evolution in the prototype young eruptive star EX Lup one decade after the outburst | We propose to obtain the first proof of the chemical changes in the cold molecular content of a protoplanetary disk induced by a powerful heat flash from an accretion outburst. Accretion variability is a general characteristic of young Sun-like stars. In the most extreme cases, accretion rate may increase by several orderd of magnitude for a period of several months. The systematic study of the effects of such powerful irradiation and heating events has just started recently, when our group discovered the crystallization of silicate grains and changes in the infrared molecular lines in the disk of EX Lup, the prototype of the EXor class of young eruptive stars. EX Lup underwent an outburst in 2008 and has been in quiescence ever since. We made a time-dependent chemical model predicting several orders of magnitude increase in the abundance of gas-phase molecules such as HCO+, HCN, HNC, CN, C2H, and H2CO, an effect still visible a decade after the outburst. Our proposed ALMA observations will explore the chemical composition of the gas in EX Lup's disk and has the potential to prove our predictions on the chemical changes induced by the accretion outburst for the first time. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-02-23T13:46:00.000 |
| 1876 | 2023.1.00265.S | 0 | Variations in the spinning dust spectrum of Rho Oph W | The diffuse galactic signal at cm-wavelengths is dominated by the excess microwave emission (EME, also called anomalous microwave emission). The EME is conspicuous in PDRs. A widely accepted interpretation of EME is electric dipole radiation from spinning very small grains, or spinning-dust. PAHs could account for the EME. A characteristic of spinning dust is the Boltzmann cut-off above 40GHz, imposed by the rotation frequency of the smallest grains. This cut-off provides a measurement of the minimum size of the carriers. We propose a Band1 mosaic of the Rho-Oph-W PDR, which is the brightest EME source clear of free-free contamination. Previous ATCA 17GHz-39GHz images point at spectral variations in Rho-Oph-W, which could be interpreted in terms of a gradient for the minimum PAH size into the PDR. ALMA may dramatically improve the 39GHz image, and will allow an accurate 20-39GHz spectral index map with which to map the Boltzmann cut-off. The data may also provide the serendipitous detection of fine-structure in the EME spectrum or PAH rotational lines, as well as carbon radio-recombination lines, which would test collisons with C+ ions as the grain spin-up mechanism. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2025-04-01T13:40:41.000 |
| 1877 | 2017.1.00984.S | 130 | Starburst-driven superwind in the nearby galaxy NGC 1808 traced by CI | Multi-line imaging of galactic superwinds is essential to determine the energetics of outflowing gas and understand how the winds regulate star formation in their host galaxies. In this study, we propose observations of atomic carbon CI (J=1-0 at 492 GHz) complemented with molecular gas tracers (mainly CO) in the central region of NGC 1808, a nearby starburst galaxy with a superwind. We aim to: 1) Measure the distribution of atomic carbon gas with respect to the molecular gas and tracers of star formation. A comparison of atomic and molecular lines at high resolution (25-50 pc) would allow us to determine the physical conditions (kinetic temperature and density) of molecular gas and reveal the structure of the photodissociation region (PDR) in the starburst environment. 2) Measure the CI flux in a resolved superwind to analyze whether CI traces the same bulk molecular gas as CO, and search for CO-dark gas in the outflow. The derived physical conditions will be used to construct a PDR model for the outflow gas. Such model can become a reference for interpreting CI and CO data at high redshift, where superwinds are considered to be a major feedback mechanism in galaxy evolution. | Starbursts, star formation | Active galaxies | 2020-02-19T00:00:00.000 |
| 1878 | 2017.1.00607.S | 55 | Rosette Globulettes | Our previous observations and modelling of very tiny molecular clouds, called globulettes, that reside in H II regions surrounding young stellar clusters, open a number of questions regarding their nature and fate. Why do most objects lack tails and bright Halpha-emitting rims? How long can they survive in the hot nebular gas and UV radiation field? Are they gravitationally unstable to form free-floating planetary mass objects and low-mass brown dwarfs to be ejected into interstellar space? The results from our first, preliminary ALMA observations of two objects in the Rosette Nebula were a surprise to us since they indicate that the objects contain cores that are much more massive and dense than inferred from our previous surveys. The total masses appear to be at least 4 times larger than estimated before, and obviously the objects can be gravitationally unstable. We still lack some crucial data to confirm the findings, and we are anxious to publish these important results quickly. The proposed observations will provide unprecedented strong evidence for a new mechanism creating free-floating brown dwarfs. It will thus have an impact on the wider field of low-mass star formation. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-11-28T16:36:32.000 |
| 1879 | 2017.1.00001.S | 60 | A sub-kpc search for obscured substructures in z ~ 2 star-forming `main-sequence' galaxies | Evidence is mounting that galaxies assembled most of their stellar mass via accretion of cold gas, leading to gas-rich, unstable disks and disk-wide clumpy star formation. Indeed, rest-frame UV images show bright star-forming clumps in galaxies at z ~ 2. But ALMA images now show that these clumps contain only a small fraction of the young stars; the star-forming clumps predicted by theory must be heavily obscured, or our picture of galaxy assembly needs to be re-thought. We will search for clumps in the obscured, intensely star-forming regions of z ~ 2 galaxies by observing the two highest S/N SFGs found in the ALMA HUDF survey that are on the main-sequence and show no sign of AGN. We propose sub-kpc resolution 870 micron dust continuum imaging of them; size constraints from ALMA HUDF images guarantee effective investment of significant ALMA time. Finding obscured clumps will revolutionize our view of the type of clumps that contribute to bulge assembly and provide critical inputs for simulations. Finding smooth disks at z ~ 2 may imply clump migration occurred at earlier times, guiding the search to higher redshift, or it may require new mechanisms facilitating bulge formation. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-02-22T01:01:25.000 |
| 1880 | 2021.1.00393.S | 280 | How do nuclear outflows impact molecular gas reservoirs in high-redshift luminous quasars? | We propose to observe the molecular gas via the CO(3-2) emission line in 50 luminous quasars at 2.1 | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-08-30T14:03:16.000 |
| 1881 | 2015.1.00920.S | 21 | Spatially resolving the CO excitation in a lensed, normal star-forming galaxy at z=1.7 | CO observations are widely used to assess the molecular gas content of galaxies. At high-redshift, only the higher CO transitions are accessible at submillimeter wavelengths. The CO excitation ladder needed to convert such measurements to a molecular gas mass is very poorly understood, with up to an order of magnitude uncertainty in the conversion factor for high-J lines. Recent observations and numerical simulations are finding a correlation between CO excitation and star formation surface density, with much higher excitations for massive star-forming clumps with high SF surface densities. We propose observations of the CO(3-2), CO(6-5) and CO(8-7) transition for an exceptionally bright lensed galaxy at z=1.7. Together with proposed CO(1-0) observations from the eVLA, the extreme magnification and extent of the arc will allow us to spatially resolve the excitation ladder over multiple clumps and interclump regions, even at moderate resolution of 1.5". This will be the first spatially resolved observation of CO excitation in a normal star-forming galaxy at high redshift and a direct test of current theoretical models | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-06-14T00:00:00.000 |
| 1882 | 2016.1.01376.S | 81 | Characterizing Chemical Composition of the Isolated Low-Mass Protostellar Core B335 | B335 is a low-mass protostar in an isolated condition, and has been subject to extensive studies on star formation processes as an ideal target. On the other hand, its chemical compositions have not been investigated in detail. Our recent observation with ALMA at a 0.5" resolution has revealed that B335 harbors various complex organic molecules (COMs) such as HCOOCH3, NH2CHO, and (CH3)2CO in the vicinity of the protostar, indicating that this source is definitively a hot corino source characterized by rich COMs. The lines of COMs and related species show very broad line width. Since the COMs are most likely evaporated from dust grains at the temperature higher than 100 K, we can constrain the size of the emitting region from the observed flux density to be larger than 17 AU. Hence, we will be able to resolve it at a resolution of 0.1" (10-15 AU) at least partly. With this motivation, we propose to observe the COMs line at this resolution to explore their distribution and kinematics. The result will make essential contributions in characterizeing physical properties and chemical compositions of this important source. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-10-03T00:04:25.000 |
| 1883 | 2019.1.00426.S | 6 | Dark matter halo substructure at z>1 | We propose a powerful and fundamental test of dark matter models by searching for halo substructure along the line of sight to the z=3.2588 strong gravitational lens G12v2.30. The ALMA Science Verification data on the lensed galaxy SDP81 from the Herschel ATLAS has already been used to demonstrate the existence of a single 1e9 Msun clump along the line of sight. It is not widely realised that ON ITS OWN this 1e9 Msun clump is a challenge to dark matter halo models. Our target has about 5x the expected amount of substructure as SDP81, because of the higher lens redshift (1.225 as opposed to 0.299). We request band 3 observations at the highest angular resolution with the C43-10 array, to the same mass sensitivity as achieved in SDP81. If substructure is as prevalent as suggested by SDP81, we expect a striking signal in G12v2.30. These observations will test a fundamental prediction of Lambda CDM structure formation and pave the way for comparative constraints on CDM and Warm Dark Matter at higher resolutions / higher frequencies, as well as resolving the background hyperluminous starburst galaxy on scales below 50 parsecs. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2022-10-29T01:20:29.000 |
| 1884 | 2019.1.01063.S | 44 | The Kinematical Transition between the Envelope and Core around Young Embedded Protostars | It is still unclear what fraction of the initial core mass and angular momentum is accreted onto protostars or disks during the low mass star formation process because the kinematic information over high dynamic ranges lacks. These issues are essential to understand what determines the solar-type stellar mass. The crucial problem is that the kinematic structure between a disk/inner envelope scales (~100 - 1000 au) and core scales (~several x 1000 au) are missing. In order to fill the missing link, we propose the line mapping (~1.7'x1.7'; 0.07 x 0.07 pc) observations with ACA in the C18O 2-1 line toward four protostars at different evolutionary stages at angular resolutions of ~6.4''(~1000 au). We have revealed the kinematic structures of these four sources on a disk to envelope scale with ALMA 12-m array though the information > 1000 au lacks. Proposed ACA observations will enable us to probe the kinematics on the envelope to the core scales, which can not be covered by ALMA 12-m array, and determine the kinematical transition from the envelope to the core. With ALMA results, we will access to the kinematic structure on the whole scale of the star formation. | Low-mass star formation | ISM and star formation | 2021-04-16T05:56:30.000 |
| 1885 | 2015.1.00188.S | 20 | Molecular Knots in the Crab Supernova Remnant | We propose to measure the CO 3-2 emission from bright H2-emitting knots and absorbing dust blobs in the Crab Nebula. This will provide a critical test of how energetic photons and particles produced in a young SN remnant interact with diffuse gas, cleanly differentiating between competing models. Only ALMA has the sensitivity and resolution to execute this test. We will study four locations with contrasting properties. Our detailed observations and Cloudy models of these knots suggest that the Crab filaments present an exotic environment in which H2 emission comes from a mostly-neutral zone probably heated by cosmic rays produced in the SN. Our model robustly predicts that the CO 3-2 line strength should be 1800 mJy km s-1, hundreds of times stronger than CO 1-0 and easily detectable by ALMA. The H2 emitting knots in the Crab present a novel phase of the ISM representative of many important astrophysical environments | Supernovae (SN) ejecta | Stars and stellar evolution | 2017-09-23T21:06:18.000 |
| 1886 | 2013.1.00798.S | 11 | Characterising the gas and dust distribution in the disc surrounding IM Lupi | The first steps of planet formation are believed to be the growth of initially small, micrometric dust grains and their decoupling from the gas phase via vertical settling and radial migration. IM Lupi is an ideal laboratory to validate and quantify these theories. It is a southern T Tauri star with one of the best characterised protoplanetary disc. We have performed extensive modelling of the currently available data and showed that the disc displays strong evidence of dust evolution: grain growth and vertical settling. We propose to obtain band 3 and band 6 continuum and CO isotopologues observations to map the spatial distribution of the millimetre-sized dust grains and molecular gas and to compare them with the spatial distribution of micrometric grains observed in the near-infrared. The disc is large, bright in the molecular lines and at an intermediate inclination (50 degrees) making it an ideal target to accurately locate both the dust and gas components. These observations will allow us to unambiguously constrain the degree of radial migration of the dust grains and determine how strong is the dynamical coupling between gas and dust. | Disks around low-mass stars | Disks and planet formation | 2016-07-31T10:13:29.000 |
| 1887 | 2015.A.00018.S | 1 | [OIII] line kinematics of a Lya emitter at z=7.2 | We have detected the [O III] 88 micron line from a z=7.2 LyA emitter (LAE) with a >5sigma significance with ALMA Band~8 observations in Cycle~2. The current data also show marginal (~3sigma) red- and blue-shifted high-velocity components around the line. We here request additional Band~8 observations of the line for the following two aims: (1) to confirm the high-velocity components and (2) to examine whether the components are explained by a rotational motion or outflow/inflow. This program will be the first study of kinematics in LAEs in the reionization epoch, about a decade prior to studies using ultraviolet metal emission lines with ELTs. Since it has turned out that the observing chance for this LAE with a 0.1'' spatial resolution is much less in Cycle~4 than in the rest of Cycle~3, we urgently propose this program as a DDT one in Cycle~3. | Lyman Alpha Emitters/Blobs (LAE/LAB), Galaxy structure & evolution | Galaxy evolution | 2017-05-01T05:17:00.000 |
| 1888 | 2023.1.00715.S | 0 | Virgo Filaments: mapping CO in HI-deficient galaxies | It is now well established that galaxies are gas deficient in galaxy clusters, such as Virgo, the benchmark cluster in the local Universe. We want to explore the influence of environment in cosmic filaments inflowing on the Virgo cluster to quantify the degree of pre-processing in such over-dense structures. From a survey comprised of Halpha mapping, HI and CO global contents of hundreds of galaxies in Virgo filaments, we ask to observe 7 spiral galaxies that show high HI deficiency. They have thus likely experienced environmental processing of their HI envelope, as they moved through the dense filaments. We now want investigate the effect of the environment in processing the denser molecular gas feeding star formation. Maps in CO(1-0) covering both central and the outer regions of the galaxies will serve the following goals. We will i) determine their molecular gas distribution; ii) get insight into the perturbation level, thus distinguishing between stripping and starvation by lack of gas supply; iii) compare their molecular morphology to the ionized gas and determine the star formation efficiency. | Spiral galaxies, Galaxy groups and clusters | Local Universe | 2025-04-08T11:03:30.000 |
| 1889 | 2017.1.01526.T | 150 | A Precision Test of Gamma-ray Burst Afterglow Models | GRBs are powered by extreme compact objects (e.g. black holes or magnetars) that eject matter at ultra-relativistic velocities (Lorentz factor >>100). This makes them ideal laboratories to study radiation processes in extreme conditions. Up to now the Swift satellite has detected >1000 GRB afterglows but only 20-30 were bright enough for extensive follow-up from radio to X-ray wavelengths to provide crucial constraints on the radiation processes. Swift has been in orbit for more than 11 years. Although all systems are still fully operational, the window to test the afterglow models gradually gets smaller. Those tests are fundamental and address key difficulties in understanding physics of cosmic particle-accelerators. Because of this, we propose a joint ALMA+JCMT+NOEMA proposal to study one GRB afterglow with a peak flux of >1 mJy from early (hours) to late times (months) for the first time. We propose to secure 5 epochs at 92 and 332 GHz separated by 7-14 days in each band. We will complement these observations with X-ray to radio data to model the broadband afterglow. This allows us to precisely test models and characterise non-standard radiation components. | Gamma Ray Bursts (GRB) | Cosmology | 2019-05-30T09:35:57.000 |
| 1890 | 2016.A.00043.T | 23 | ALMA observation of the nearest short GRB | Short gamma-ray bursts (sGRBs) are presumed to result from compact object mergers (of two neutron stars, or one neutron star and one stellar mass black hole). Today, Fermi detected sGRB 170817A and we detected a bright optical afterglow in subsequent follow-up, suggesting that the sGRB may be the nearest detected to date. Unlike the X-ray and optical emission, the millimeter afterglow emission will peak on timescales of several days, maximizing the chance of detection and allowing us to measure the jet energy and collimation and the circumburst density. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2018-04-10T22:15:57.000 |
| 1891 | 2013.1.01064.S | 19 | A dusty dwarf galaxy at z=7.37 | A1689-zD1, a star-forming galaxy lensed by the foreground cluster A1689, is the brightest z>7 galaxy candidate known. We have recently discovered its redshift to be z=7.37 using very deep near-infrared continuum spectroscopy of the Lyman break. We request an observation of the source with ALMA to characterise the dust mass and infrared star-formation rate and to detect the [CII]158μm line to determine the redshift to high precision. Cycle 0 observations of the lensing galaxy cluster serendipitously detected the source in band 6 at modest significance, showing a significant, but low, dust mass. We expect a clear detection of both the [CII] line and the continuum in 4 bands in this modest, UV bright galaxy only 700 Myr after the big bang. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 2016-01-12T15:25:59.000 |
| 1892 | 2017.1.00048.S | 34 | Dissecting the Most Extreme Obscured Starburst Nucleus known at z>5 | Cosmological simulations suggest that massive galaxies formed in the densest regions in the very early universe through hierarchical buildup, predicting the existence of massive protoclusters of intensely star-forming galaxies at high redshift. We have identified such a unique region within ~1 billion years of the Big Bang, hosting an extreme starburst and 14 normal star-forming galaxies. Advancing upon our highly successful efforts related to this region in cycles 0-4, we here propose to measure the detailed physical properties of the dust (i.e., the extinction-corrected brightness temperature, luminosity, star formation rate surface density, and dust optical depth) in the hot (>49K), compact (<250pc), optically-thick nucleus of the best-studied unlensed starburst at z>5 (i.e., not limited by lens modeling accuracy) at rest-frame ~70um at <200pc resolution. This unprecedented investigation of the exceptional central starburst in a rare galaxy protocluster at z=5.3 will critically constrain the extreme properties of starburst nuclei at such early epochs, which dwarf any galaxies in the present-day universe. | Starbursts, star formation, Galactic centres/nuclei | Active galaxies | 2019-05-25T19:27:44.000 |
| 1893 | 2019.1.01039.S | 36 | Tracing accretion onto a YMC progenitor candidate in M33 | We propose 12CO(1-0) and 12CO(3-2) observations of the only known potential YMC progenitor molecular cloud in M33. From previous observations, the target cloud is unresolved on 8 pc scales with a mass of ~10^5 Msol. The proposed observations will resolve 1 pc scales in CO(3-2), sufficient to determine if this is a YMC progenitor and which formation mechanism best describes the cloud substructure. Connected to this cloud are multiple filaments, which appear to be accreting material onto the cloud based on CO(2-1) observations. We target 4 pc scales in CO(1-0) to recover faint CO emission associated with cloud accretion. By combining with an in-hand 8 pc HI VLA map, these observations will provide an unambiguous top-down view of molecular cloud accretion from 1 to 100 pc scales. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-06-18T15:15:00.000 |
| 1894 | 2022.1.01621.S | 10 | Uncovering the next stage of organic chemical complexity in planet-forming disks | The precursors to larger, biologically-relevant molecules are detected throughout interstellar space, but determining the presence and properties of these molecules in planet-forming disks is challenging. Recent observations of disks have revealed unexpectedly high column densities of mid-sized organics such as CH3CN and HC3N, demonstrating an active carbon chemistry is at work. If this is similar to other carbon-rich astrochemical environments (e.g. dark clouds and circumstellar envelopes) then larger hydrocarbon chains should also be abundant and observable. The goal of this proposal is to search for the next stage of chemical complexity in protoplanetary disks, vinyl cyanide (CH2CHCN) and propyne (CH3CCH), for the first time. We target four disks spanning a range of spectral types, all of which show strong emission from mid-sized organics. We will provide the first view of the spatial distribution, abundance and excitation conditions of these molecules in disks. We will determine the degree to which organic chemical complexity can be built up (or retained) in the vicinity of forming planets, and reveal whether this chemistry is similar to other astrophysical environments. | Low-mass star formation, Astrochemistry | ISM and star formation | 2024-09-21T22:01:42.000 |
| 1895 | 2015.1.00768.S | 24 | Probing magnetic fields in the inner envelopes and outer disks of Class 0 protostars | We propose ALMA Band 7 dust polarization observations of 3 Class 0 protostellar cores in Serpens in order to infer the magnetic field (B-field) morphologies in their inner envelopes (0.36" resolution) and outer disks (0.08"). Recent ALMA Band 6 Stokes I data show fragmenting filamentary structure near all of the sources, suggesting that B-fields play an important role in the shaping of structure, the formation of multiple-star systems, and possibly the fragmentation of massive disks (in the case of Ser-emb 6) down to <100 AU scales. With the observations we propose, (1) we will definitively answer the question of whether B-fields are toroidally wrapped by envelope and/or disk rotation, (2) we will be able to investigate the role of B-fields in filament and multiple-star formation at the smallest scales ever observed, and (3) for the first time, we will be able to characterize the B-fields role in the fragmentation process in a massive, gravitationally unstable disk. | Low-mass star formation | ISM and star formation | 2018-04-06T20:29:00.000 |
| 1896 | 2015.1.00230.S | 41 | Mass accretion flows in high-mass star formation | The formation of high-mass stars is one of the major topics of astrophysical research, in particular the process of accretion from large-scale clouds to small-scale cores. With this proposal we aim at characterizing this process by observing three highly-fragmented massive clumps that lie in the NGC6334 star forming complex. Our previous studies show large-scale velocity gradients and mass flows of 10^-3 Msun/yr at 1-pc scales. Detailed interferometric observations, show similar levels of accretion onto the different cores at 1000-AU scales. What is the link between the two scales? How is the mass transported from 1-pc to 1000-AU scales? What is the role of the magnetic field? We plan to answer these questions by observing HCN, HCO+ and other tracers: (i) ALMA high-fidelity images will permit to search for 'accretion channels' that connect the cloud/clump with the cores; (ii) The spatial distribution and line shapes (containing information of the accretion) will be modeled with a 3D radiative transfer pipeline developed by us; (iii) The HCO+/HCN ratio, as a probe of the magnetic field, will complement the already available information on the magnetic field in this region. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-09-11T08:30:43.000 |
| 1897 | 2015.1.00872.S | 127 | Is the central sub-kiloparsec gas surface-density the decisive parameter for fueling supermassive black holes? | We will test whether the bulk of supermassive black holes in galaxies grows from gas transported by gravitational instabilites from kpc all the way to the edge of the accretion disk. As a difference to the widely popular but empirically unproven scenario of major galaxy merger-driven inflow of gas, numerical simulations suggest that if for whatever reason the gas density inside the central ~1 kpc is sufficiently high, then a gaseous disk can become gravitationally unstable, forming a cascade of nested, self-propagating instabilities providing efficient gas transport to the very <1pc-center. The clear and testable prediction is a systematically higher mean gas surface density inside the central ~200pc of strongly accreting QSOs, compared to inactive galaxies with otherwise identical mass, SFR, etc. We will test this hypothesis by measuring CO(2-1) inside this region for each five highly accreting QSOs, and z-, mass- and SFR-matched inactive galaxies. The proposed observations, only possible with ALMA, would provide a confirmation of the fuelling hypothesis at >95% significance and answer this decade-old fundamental question on black hole growth. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-11-30T18:48:35.000 |
| 1898 | 2016.1.01435.S | 64 | ALMA-LEGUS: Connecting Star Formation to its Fuel | We propose to study dust and star formation on scales of tens of parsecs by mapping the submm/mm continuum in the well-studied nearby spiral NGC628, with unprecedented sensitivity and physical resolution. We will use the dust maps in conjunction with the star formation maps obtained by the HST LEGUS project to investigate whether and how the far-infrared/submillimeter continuum slope, and dust mass determinations, are impacted by variations in the local stellar radiation field produced by different tiers in the hierarchical star formation ladder. When combined with existing HI maps, the dust maps will provide a complementary map of the molecular gas, which we will compare with archival ALMA CO(2-1) maps to constrain the CO-dark component within this galaxy. We will ultimately derive an accurate accounting of all the star-forming and non-star-forming molecular gas, which we will use to investigate the local scaling relation(s) between star formation and gas surface densities. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2018-01-26T00:13:23.000 |
| 1899 | 2019.1.00471.S | 10 | A Comprehensive View of Star Formation on 300pc Scales at z=4 from ALMA and JWST | We propose high-resolution CII and continuum imaging of SPT2147-50, a z=3.76 lensed dusty galaxy set to be observed by JWST as part of the TEMPLATES Early Release Science program soon after launch. The JWST data will provide panchromatic rest-UV to optical imaging and IFU spectroscopy of H-alpha, Pa-alpha, and PAH emission at up to ~0.1" resolution -- in other words, virtually every major SFR indicator used at high redshift. We propose to match this spatial resolution in dust continuum and CII emission, the two most common long-wavelength SFR indicators, in order to assemble a comprehensive view of star formation at matched physical scales of ~300pc at z~4. While CII is commonly used as an SFR indicator at high redshift, its interpretation is difficult because the line arises from gas in a wide variety of conditions. Even before the launch of JWST, these data will allow us to investigate the origins of scatter in relations between L_CII and SFR and in the `CII deficit'. Cycle 7 is the *only* chance to acquire these data before the launch of JWST, ensuring that high-quality dust and CII maps will be available to the community for the first joint ALMA+JWST multiwavelength studies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2022-07-02T16:40:22.000 |
| 1900 | 2019.2.00208.S | 9 | The first minisurvey for neutral carbon gas in debris disks around G-type stars to test secondary gas disk models | One of the most unexpected discoveries of ALMA was the detection of CO gas in debris disks. Intriguingly, most detections are in disks around A-type stars, while no CO was ever detected in debris disks around G-type stars. A current model, however, predicts the production of neutral carbon in collisions of planetesimals, and CI may trace cold gas better than CO. To detect carbon and to observationally test the current secondary gas disk models, we propose to measure the CI 492 GHz (Band 8) emission in four dust-rich debris disks around G-type stars. We will measure the quantity of neutral carbon gas and its spatial distribution with respect to the parent planetesimal belt in each system. The detection of CI in CO-poor disks will provide strong support for the new secondary disk models, and pave the way for new type of future gas surveys in debris disks. In our Solar System comets played an important role in water/volatile delivery to Earth. Detection of carbon gas in outer debris belts can demonstrate that similar volatile-rich planetesimals are available in these young analogues of our Solar System, too. | Debris disks | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 1901 | 2021.1.00499.S | 49 | Probing Gas, Dust, Stars, and Star Formation Activity down to 100-pc Scales using Strong Gravitational Lensing | Herschel and other submm surveys have shown that dusty star forming galaxies (DSFGs) with SFR 100-1000 Msun/yr are ubiquitous in the early Universe. Yet, they remain a challenge for theoretical modeling because of complex interplay among gas accretion, star formation, and feedback processes occurring on 10-100 pc scales that are beyond observational or numerical resolution today. We address this challenge observationally by utilizing the magnifying properties of strong gravitational lensing. A Cycle 5 shallow, low-resolution imaging survey of 15 Planck-selected DSFGs, with apparent luminosity exceeding 10^14 Lsun, successfully demonstrated that these targets are all strongly-magnified sources at z>1. To provide a direct view of the most luminous DSFGs known at spatial scales where the star formation process usually takes place, we propose deeper, higher-resolution CO(3-2) and 1mm continuum observations of the 4 best-suited Planck starbursts with bright CO lines, clear lensing geometries, and robust lens models. These targets are situated at the peak of Cosmic SF evolution (z=2-3), and the results of this analysis will offer insight into the physical conditions of high-z galaxies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2022-12-12T00:02:43.000 |
| 1902 | 2017.A.00042.T | 25 | Caught in the act: H2O masers flaring in a low-mass protostar | Water masers offer the possibility to diagnose gas motions in the disk and outflow of deeply embedded protostars at incredibly high angular precision, even by ALMA standards. Maser monitoring observations show that protostars flare, and the brightness in masers increase many times over periods of just a few months. Thus, masers provide a unique insight into the time variability of deeply embedded protostars. One example of such water maser variability is seen toward the low-mass Class 0 protostar IRAS16293-2422, where the 22 GHz water maser has increased in brightness by a factor of 20 over 2.5 months (mid-March to June, 2018, increase from 240 to 4700 Jy), but only observed with a single dish. We here propose for DDT time to observe this flare with ALMA in the 183 GHz H2O maser line. These observations will: (i) reveal the location of the maser spots irrespective of ALMA configuration; (ii) allow us to infer the gas temperature by comparison to the 22 GHz data; (iii) complement our accepted A-ranked Cycle 5 ALMA proposal nominally to be carried out in September by allowing us to track the flare; and finally (iv) open up a new window for ALMA to track gas dynamics on small scales. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-01-17T12:22:46.000 |
| 1903 | 2016.1.01454.S | 192 | Unveiling the Dustiest Galaxies in the Universe with ALMA | Using new ultra-deep near-infrared data from the UltraVISTA survey, we have uncovered a remarkable population of massive galaxies at z ~ 2 that appear to have extraordinary dust obscuration of their stellar populations, Av = 3.0 - 5.0. This amount of obscuration is substantially more than seen in submillimeter galaxies, which typically have Av = 1.5 - 2.5. If truly this dusty, this population are undoubtedly the most dust-obscured galaxies yet seen. The largest uncertainty with these galaxies are their redshifts, as even with ultra-deep 38-band UV/IR/MIR photometric data, the lack of strong features in their SEDs leaves considerable uncertainty in the photometric redshift, and hence the total dust content. They are far too faint for conventional optical/NIR spectroscopy (R < 27.5, H < 24.5), so we request Band 6 spectral scans for the four most strongly star-forming of these galaxies. Our primary goal is to detect multiple CO transitions to pinpoint both their spectroscopic redshift and to measure approximate gas fractions. Once redshifts for this population are confirmed, this will open up an exciting opportunity to study a new population of extraordinarily dusty galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-04-27T22:17:43.000 |
| 1904 | 2024.1.01086.S | 0 | Spatially Resolved Dust in a Spectacular Lensed Quiescent Galaxy at z=2 | Taking the first steps into new discovery space with a boost from strong gravitational lensing, ALMA has now directly detected dust in lensed quiescent galaxy MRG-M0138 at z=1.95 that implies a remarkably low molecular-gas fraction of 0.6% and an extreme gas surface density. However, constraints on the dust SED hinge on assumptions about the dust temperature and overall dust shape. Furthermore, centrally-concentrated unresolved dust also drives uncertainties in recovered stellar populations. We propose to reduce systematic uncertainties in Td and SFR for this spectacular galaxy, providing high resolution data complementary to existing HST/grism and JWST NIRSpec/IFU spectroscopy. This program will yield (1) 200-pc-scale dust-continuum maps (B6) at rest-frame 430um, and (2) global constraints on Td and IR luminosity (B9) at rest-frame 150um. Only ALMA can provide the high spatial resolution data to complement existing optical to NIR space-based data, enabling a spatially resolved SED modeling effort to illuminate the physical mechanisms driving the formation and quenching of a unique laboratory. | Gravitational lenses | Cosmology | 3000-01-01T00:00:00.000 |
| 1905 | 2013.1.01204.S | 9 | Hierarchical Structures and Kinematics of a 30pc IR-dark Filament | Recent Herschel images have shown increasing evidence that star forming dense cores are preferentially located along dense ridges (or filaments) in molecular clouds, but little is known how these cores are formed in the context of filamentary structures, especially in the high-mass case. We propose to obtain high fidelity mosaic images in 3mm dust continuum and N2H+/HNC (1-0) lines of the filamentary IRDC G11.11-0.12, a high-mass analogue to the well-studied low-mass star forming filament Taurus L1495/B213. This IRDC represents a quasi-sinusoidal shaped filament containing hierarchical structures at multiple scales from ~1 pc down to ~0.01 pc. The proposed observations will enable us to study the detailed kinematics associated with the hierarchical structures, and to investigate how dense cores form and evolve physically and chemically within filaments. The proposed study will (1) provide a full picture of the structures, kinematics, dense core formation and evolution, of a giant molecular cloud that has a simple filamentary morphology, (2) have a distinguishing power to leading high-mass star formation scenarios, and (3) set a model for other filamentary complexes. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-10-15T00:00:00.000 |
| 1906 | 2018.1.01205.L | 2247 | Fifty AU STudy of the chemistry in the disk/envelope system of Solar-like protostars (FAUST) | The huge variety of planetary systems discovered in recent decades likely depends on the early history of their formation. The proposed FAUST Large Program focuses specifically on the early history of Solar-like protostars and their chemical diversity at scales of ~50 au, where planets are expected to form. In particular, the goal of the project is to reveal and quantify the variety of chemical composition of the envelope/disk system at scales of 50 au in a sample of Class 0 and I protostars representative of the chemical diversity observed at larger scales. For each source, we propose 50 au spatial resolution observations of a set of molecules able to: (1) disentangle the components of the 50-2000 au envelope/disk system; (2) characterise the organic complexity in each of them; (3) probe their ionization structure; (4) measure their molecular deuteration. The output will be a homogeneous database of thousands of images from different lines and species, i.e., an unprecedented source-survey of the chemical diversity of Solar-like protostars at 50 au scales. FAUST will provide the community with a legacy dataset that will be a milestone for astrochemistry and star formation studies. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-03-08T00:00:00.000 |
| 1907 | 2015.1.00027.S | 186 | AGN feedback and molecular line flux ratios in dust/gas-rich ultraluminous luminous infrared galaxies | We propose molecular line observations of nearby dust/gas-rich ultraluminous infrared galaxies (ULIRGs) whose energy sources (AGN or starburst) are quantitatively well-calibrated through infrared spectroscopy. Our scientific goal is to establish a firm energy diagnostic method of dust/gas-rich galaxies, based on bright molecular line flux ratios at the dust-extinction-free (sub)millimeter wavelength range. It is suggested that enhanced HCN emission is empirically an excellent AGN indicator, but its validity and physical origin is still unclear. By combining with our ALMA Cycle 0 and 2 data, we aim to obtain molecular line flux ratios for multiple sources in each energy source category, at multiple transition lines of HCN/HCO+/HNC, to see the overall trend of molecular line flux ratios as a function of primary energy source, and to understand its physical origin. ALMA is best suited, because of (1) its high sensitivity and stable spectral baseline, and (2) its high spatial resolution to pinpoint AGN-affected molecular gas at galaxy nuclei. Our data will be a valuable basis to interpret future ALMA molecular gas observational results of the cosmologically important ULIRG population. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2017-04-01T12:27:54.000 |
| 1908 | 2023.1.00854.S | 0 | Tracing the ISM enrichment from massive stars at the peak of cosmic starformtion | 12C and 13C abundance ratios have long been considered to be a diagnostic of the enrichment history of the ISM and as a cosmological probe of stellar physics and galaxy evolution. But at cosmological distances until today only one upper limit for [12C]/[13C] has been published in the literature. This short coming stems from the fact that the determination of (in particular) [12C] requires detailed modelling of the optically thick 12CO lines in conjunction their rare isotopes based on multiple transitions. Building up on ALMA cycle 9 observations we propose to measure the [12C0]/[13C0] and simultaneously the [12C0]/[C180] enrichment history at cosmological distances in a sample of 8 bright CO emitters selected from the South Pole Telescope (SPT) survey to constrain the star formation history of these massive systems at the peak of cosmic star-formation. Our experiment is design such that at the same time we will be able to test recent claims for a top heavy IMF in these systems based on the 13CO and C18O ratios and to put this finding on a larger statistical footing. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2025-04-10T18:55:20.000 |
| 1909 | 2017.1.01500.S | 93 | The diffuse molecular component in the nuclear bulge of the Milky Way | The old and well established view of the interstellar medium in the Galactic center region suffered an important change with the recent discovery of a low density gas component with an excitation temperature close to that of the cosmic background radiation, using the ALMA telescope. Given our successful pilot study in Cycle 1, aimed to detect such diffuse gas in the bulge of the Galaxy, we propose to perform a complete characterization of the physical properties of this newly discovered interstellar medium component. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-02-23T16:46:20.000 |
| 1910 | 2021.1.00560.S | 18 | Detecting winds from RGB stars | Measurements of mass-loss rates from red and early-asymptotic giant branch (RGB/early-AGB) stars are an order of magnitude too low to explain the difference in mass between RGB stars and their dusty AGB progeny. Part of the problem is a lack of calibration of chromospheric mass-loss rate indicators. We proposal a pilot study to make the first conclusive measurements of molecular mass lost from 12 bright RGB/early-AGB stars, plus alpha Her, a more-massive star which is also transitioning from a chromospheric to a dusty wind. These will test the validity of the mass-loss rates and wind velocities of chromospheric indicators. We will also measure the radio photospheric flux of these stars, giving insight into their chromospheric heating. We will also resolve the envelopes of at least some stars, giving our first indication of whether these winds are smooth, clumpy, or complex in morphology. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2023-04-18T15:16:14.000 |
| 1911 | 2018.1.00896.S | 2 | Characterizing multiple polarization mechanisms in the bright, inclined disk of IM Lup | This is a follow-up of our successful Cycle 4 ALMA polarization observations of the large, bright, inclined protoplanetary disk IM Lup. Our Band 7 observations, published in Hull et al. (2018), show a polarization morphology consistent with dust scattering. Here we propose to observe IM Lup in both Band 3 and Band 6 in order to characterize the polarization at longer wavelengths. The results in HL Tau by Stephens et al. (2017) show radiative alignment dominating at Band 3; scattering at Band 7; and a superposition of the two at Band 6. We aim to test whether the transition from scattering to radiative alignment is the same for an optically thinner and significantly more evolved Class II source like IM Lup. | Disks around low-mass stars | Disks and planet formation | 2020-08-14T15:02:54.000 |
| 1912 | 2019.1.00657.S | 34 | Black hole mass measurements in the most MASSIVE Galaxies | Massive early-type galaxies (ETGs), as the end point of galaxy evolution, are the subject of intense interest. Yet, their complex formation histories remain obscure. In lower-mass objects black holes (BHs) are strongly correlated with properties of the stellar bulge implying co-evolution between the BH and stellar components. The BH mass in massive ETGs, however, does not correlate well with galaxy parameters. The most massive ETGs and their central BHs therefore may have followed different evolutionary paths from their less-massive counterparts. We propose here to complete our cycle-4, 5 and 6 observations of the molecular discs that lie in the heart of two of the most massive molecular gas hosting ETGs in the local universe, in order to estimate their SMBH masses. With these observations we can test the feedback paradigm, constrain the environmental dependance of SMBH-host galaxy relations, provide important cross-checks on SMBH mass measurement techniques and anchor studies of the SMBH-host galaxy relations which use molecular gas. In this way a short investment of ALMA time can help reveal more about the complex formation histories of the most massive galaxies in our universe. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2022-09-09T19:58:18.000 |
| 1913 | 2018.1.01740.S | 11 | Looking Through the Cosmic Lens: probing the dark matter in lensed high-redshift galaxies using rotation curves | Determining the dark matter structure is a major goal to understand the galaxy formation and evolution in a 'Cosmic Perspective'. Recent findings of declining rotation curves in high-redshift star-forming disks suggests that massive galaxies at z~1.5-2 have dark matter fractions that are negligible. However, these results rely on stacking, and the assumption adopted to normalize the rotation curves may affect strongly the resulting stacked rotation curve shape. Thus, direct observation of the outer part of the rotation curves is needed. The measurement of rotation curve is challenging, especially for the high-redshift galaxies when HI observation becomes extremely difficult. Nevertheless, strongly gravitational lens offer high magnification around its caustic lines, boosting sensitivity in the outer regions of the lensed background disk galaxies. This will allow us to map the outer part of rotation curves, pinpoint the structure of dark matter. Therefore, we here propose deep imaging of the [CI] lines, a robust extended gas tracer, to measure the rotation curve in two strongly lensed high-redshift dusty star-forming galaxies, taking the advantage of such a technique. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2021-01-29T17:26:34.000 |
| 1914 | 2018.1.00452.S | 184 | The formation of interstellar formamide | Many of the organic molecules detected in interstellar molecular clouds are also found in comets. These molecules could have played an important role in the pre-biotic chemistry of an early Earth which was subjected to cometary bombardment. There is disagreement between astrochemists about whether formamide (NH2CHO) is formed predominantly from HNCO hydrogenation in ices or from H2CO in the warm gas. There has been evidence published favoring both in observations and laboratory work. As a molecular species, formamide is of astrobiological importance because it contains a peptide bond and could be the predecessor to amino acids. This ubiquitous species has been detected in the interstellar medium, star-forming regions, and solar system bodies (comets, moons) indicating that it can survive the process of planetary system formation. Investigating formamide and two other pre-biotic species, methyl isocyanate (CH3NCO) and acetamide (NH2COCH3), will grant insight into species that may have been the spark for biotic molecules delivered to Earth. We propose these ALMA observations of high- and low-mass star-forming regions to investigate the origin of these species. | Astrochemistry | ISM and star formation | 2020-08-04T03:19:51.000 |
| 1915 | 2011.0.00259.S | 0 | Testing the models for the inital steps toward planet formation: the evolution of solids in brown dwarfs disks | The core accretion scenario for the formation of planetary systems in disks predicts that the initial phases of this process are characterized by the grain growth process. In this view, the solid components of disks (dust grains) grow to larger sizes to produce planetesimals and rocky cores of planets before accreting gas from the disk. The models for grain evolution in disks have now reached a sufficient level of sophistication that can make testable predictions. These models can explain the observations of large grains in the massive disks around solar-type young stars, but do predict clearly that the grain growth process is strongly dependent on the disk mass (density). The expected masses (densities) of disks in the substellar regime are so low that models predict no grain growth. ALMA Early Science offers the unique possibility to perform this test and verify whether grain growth can occurr in BDs disks. We propose to observe the four disks around brown dwarfs that are already known to have disks detected at millimeter wavelengths and to probe the presence of large grains by measuring the spectral energy distribution at millimetre wavelengths. | Disks around low-mass stars, Brown dwarfs | Disks and planet formation | 2013-12-05T08:43:00.000 |
| 1916 | 2019.2.00094.S | 182 | Are There High-mass Prestellar Cores in Orion? | Gravitationally bound, massive (>30 Msun within r<0.01 pc), and monolithic (i.e., non-fragmenting) dense cores are initial conditions in one of the leading theoreticalmodelsof high-mass star formation. So far, only few such cores have been detected. We are carrying out a systematic search for high-mass prestellar cores in Orion, the closest high-mass star formation region. Thanks to the wealth of archival data and previous studies, we are able to narrow down the search to the 7 most massive cores in Orion. Here we propose ACA observations to (1) resolve the potential fragmentation, (2) confirm the starless nature, and (3) evaluate the virial status. With only few hours of ACA time, we can finally tell whether high-mass prestellar cores exist in Orion, the most well studied high-mass star formation region. The results will clearly impact the development of theoretical models. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2021-04-27T21:53:07.000 |
| 1917 | 2013.1.00385.S | 8 | Probing Star Formation in Quasar Host Galaxies at z~2 | Feedback from black hole (BH) growth in the quasar phase plays a crucial role in massive galaxy evolution. We propose to obtain ALMA band 6 continuum and CO (6-5) observations of a sample of 10 quasars at z~2 with existing high-resolution HST imaging. This unique sample will allow the first simultaneous study of BH growth in high-redshift quasars together with stellar population, molecular gas and star formation in their host galaxies: ALMA observations is the only way to directly probe the total star formation rate, gas mass and gas kinematics, while HST imaging and ground-based spectroscopy measure the host galaxy luminosity and stellar mass, as well as mass and accretion rate of the central BH. We will study whether quasar host galaxies follow the same star formation vs. stellar mass main sequence as star forming galaxies, whether their star formation process is enhanced by mergers or suppressed by BH activity. We will also determine the galaxy gas content and gas fraction in the quasar phase. Our observations will provide direct constraints on the mode of star formation and feedback during the peak epoch of BH growth, shedding light on the origin of BH/galaxy mass correlation. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-11-12T23:15:30.000 |
| 1918 | 2017.1.00027.S | 13 | Unveiling the Galaxy Formation Sequence | The spectacular ALMA observations of the z=3.04 Herschel galaxy SDP 81 revealed a collapsing disk containing a galaxy-building starburst. However, the short time needed for the disk to collapse suggests that SDP 81 may only represent one phase in the galaxy-formation process. We propose to observe a sample of eight of these galaxy-building starbursts in Band 6 in both line and continuum with a resolution of 0.05 arcsec, in a strategy designed to produce the same science results as the SV observations of SDP 81 but much more cheaply. Our observations will provide maps of the dust and gas in these galaxies, and the kinematics will allow us to estimate each galaxy's mass, the gas, stellar and dark-matter fractions, the relative importance of interactions and rotation; and, in the cases where there is s disk, determine whether the disk is collapsing. In general, our observations will take the study of these galaxy-building starbursts from one, possibly unrepresentative object to a statistical sample (although still of modest size), allowing us to make a first attempt at disentangling the different phases of the galaxy-formation process. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-12-20T15:26:59.000 |
| 1919 | 2018.A.00068.T | 21 | Accretion burst event in high mass YSO G24.33+0.14 | Episodic mass accretion onto a high-mass (HM) YSO is predicted to achieve an extremely high accretion rate of >10^-3 MSun/yr within short time scale. Such accretion burst events are identified recently in NGC6334I and S255IR as outbursts of radio and infrared continuum emission. At the same time, they show sudden flare of the 6.7 GHz methanol maser, suggesting that the maser flare is useful to detect luminosity change of HM-YSO triggered by accretion burst. In Sep. 2019, the newly established Maser Monitoring Organization (M2O) reported a 6.7 GHz methanol maser flare in G24.33+0.14. This is the fourth example of possible accretion bursts in HM-YSOs after NGC6334I, S255IR, and G358.93-0.03, which is another new detection by M2O in Jan. 2019. G24.33+0.14 was observed in a pre-burst phase in ALMA Cycle 3. Thus, we can investigate millimeter methanol maser variability for the first time along with continuum emission. Our multi-transition multi-epoch data will reveal luminosity/temperature change and energy/mass ejection in the accretion burst. Since the maser flare will decay within one month (e.g. some methanol lines in G358.93-0.03), immediate ToO observations are required. | High-mass star formation | ISM and star formation | 2020-07-15T08:20:44.000 |
| 1920 | 2018.1.01420.S | 24 | Are they low-mass protostars? A census of hundreds of compact sources in the Central Molecular Zone | The Central Molecular Zone (CMZ) around the Galactic center is a unique star forming environment with extreme physical conditions. How the low-mass stars in clusters in the CMZ are formed has been unknown. In previous ALMA 1.3 mm contiuum data, we identified hundreds of faint compact sources at 2000 AU scales in three massive protoclusters in the CMZ. Assuming thermal dust emission, these sources may represent a large population of low-mass protostars that are expected from the canonical initial mass function. However, the alternative possibility that they are a mix of non-thermal and thermal free-free emission cannot be ruled out. Here we propose to use ALMA to map 3 mm lines and continuum emission, to obtain spatial distributions of dense gas and estimate spectral indices of the sources, in order to assess their nature. If the majority of the compact sources are associated with dense gas and are dust emission, this will be the first time we detect clutered low-mass star formation around the Galactic center, and will be a unique oppoturnity to examine if (low-mass) star formation in the extreme environments of the CMZ can be described by the canonical IMF. | Low-mass star formation | ISM and star formation | 2021-12-31T00:00:00.000 |
| 1921 | 2012.1.00013.S | 4 | A Change of Rotation Profile in HH 111: Formation of a Keplerian Disk around a Protostar | Recently, I have mapped a nearby protostellar system HH 111 in Orion with the Submillimeter Array (SMA). A flattened envelope can be seen extending far out from the central source perpendicular to the jet axis. A roughly resolved disk can also be seen deeply embedded in the envelope aligned with it. More importantly, I have found a change of rotation profile from the envelope to the disk (Lee 2010) and a Keplerian rotation in the disk (Lee 2011), as expected in theoretical models of disk formation in star formation. I propose to map this system again with ALMA in order to re-examine the findings at higher angular and velocity resolutions with unprecedented high sensitivity. The change of rotation profile, if confirmed, would be the first seen in star formation, in support of the current theory of disk formation. | Low-mass star formation | ISM and star formation | 2015-09-17T18:35:49.000 |
| 1922 | 2015.1.00993.S | 25 | Chemical Composition in a Merging Galaxy NGC3256 | NGC3256 is late stage merging galaxy and SB/AGN activity is considered to strongly impact the chemical and physical properties of ISM. Chemical properties as traced in molecular gas composition contain significant information that will tell us the current state and duration of the SB/AGN activities, and how that is affected by the ongoing tidal interaction. The spectrum of our previous LMT line survey seems to be like SB galaxies not AGN-host galaxies, however it reflects mean value of double nuclei. High resolution and sensitivity imaging of numerous molecules with ALMA is strong tool to create accurate picture of NGC3256. In addition, molecular gas outflows are identified in NGC3256, and we try first mapping of shocked gas tracers in the nuclear outflow. | Merging and interacting galaxies, Galaxy chemistry | Galaxy evolution | 2017-04-27T13:24:51.000 |
| 1923 | 2017.1.00830.S | 42 | Black Hole Masses, central parsec gas dynamics, and Event Horizon Detectability in a sample of nearby galaxies | Resubmission: 2 galaxies delivered. 6 remain to be observed in Cycle 4. Despite it now being well established that nearly all galaxies have a central black hole whose mass scales with the host galaxy properties, we do not have a complete understanding of the physics at work. In particular, we do not know whether black holes, or galaxies, drive the scaling relations. Although we know that the M-sigma and M-L relations are incompatible in the largest galaxies, we do not know which is wrong. We are now at the limits of what can be learned with ~80 data points with substantial measurement uncertainties, and urgently require additional precision data. ALMA is capable of measuring black hole masses at high precision in a large sample. We propose observations of a modest pilot sample of nearby galaxies in order to: (1) Measure black hole masses in 3 new sources with large angular spheres of influence, (2) measure the central parsec gas dynamics in most or all 8 sources allowing us to better understand the systematics in molecular line black hole mass measurements, and (3) determine suitability for event horizon shadow resolution with the Event Horizon Telescope. | Galactic centres/nuclei | Active galaxies | 2019-01-10T08:20:19.000 |
| 1924 | 2022.1.00316.L | 143 | COMPASS: Complex Organic Molecules in Protostars with ALMA Spectral Surveys | The emergence of complex organic molecules in the interstellar medium is a fundamental puzzle of astrochemistry. Targeted observations with ALMA have opened the door to high-sensitivity spectral surveys over wide bandwidths to elucidate the chemical complexity of young stars in a systematic manner. We propose a Large Program to perform unbiased line surveys in the 279 to 312 GHz frequency range of 11 nearby Solar-type protostars. The targeted protostars are known hosts of complex organic molecules and sample different natal environments and evolutionary stages. The proposed spectral coverage will allow us to unambiguously identify complex organic molecules and their isotopologues and to accurately derive the abundances for species with abundances down to 0.01% relative to methanol. The concerted effort will provide a deep understanding of the complex organic inventories and isotopic ratios depending on the physical environment and evolutionary past. This will move the field forward in disentangling the formation of such molecules under interstellar conditions and ultimately address how much diversity in organic inventories we can expect for emerging planetary systems. | Low-mass star formation, Astrochemistry | ISM and star formation | 2025-05-27T09:59:08.000 |
| 1925 | 2015.1.00235.S | 32 | Mass loss on the RGB: reaching the limits | For stars with initial masses below about 1 Msol, mass loss on the first red giant branch (RGB) dominates that of the later AGB phase. Nevertheless, RGB mass loss is often parameterised by a simple Reimers law in evolution models. Groenewegen showed that mass loss exists in nearby RGB stars from modelling the SEDs. As follow-up, 5 stars were observed with IRAM and APEX. HIP 53449 was detected in the CO 2-1 line (and marginally in the J=3-2 line), the object with the largest mass-loss rate based on the previous analysis of the SED. The shape of the line profiles is intruiging. The expansion velocity is unexpectedly large, and there is a hint for a rotating disk. The comparison to a line emission code suggests that the CO envelope is significantly smaller than follows from the photodissociation radius. It is proposed to observe HIP53449, and the star with the next largest detection probability HIP 67665, in the CO 2-1 and 3-2 lines. The observations will unequivocally determine the line profiles. More importantly the spatial resolution of ALMA will allow to determine the size of the CO shell and show if it is indeed much smaller than the standard photodissociation radius. | Main sequence stars, Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2017-02-08T14:30:58.000 |
| 1926 | 2012.1.00108.S | 3 | A Deeper Look into the Life Cycle of the Molecular Gas in the Nearest Nuclear Starburst: GMCs, Molecular Superwind, and Feedback | We propose to complement our ALMA cycle 0 observations of NGC253, the nearest nuclear starburst, with new observations including ACA+TP. These new ALMA capabilities in cycle 1 will allow us an unprecently deep look at the outflowing molecular gas. Our cycle 0 CO observations (released to us in late April, recalibrated, and reimaged) show a groundbreaking picture of molecular gas entrainment in a superwind. In them we are able to identify expanding shell structures in the starburst unequivocally associated with high-velocity molecular gas tendrils (Figs. 2 and 3). We are hampered, however, by the lack of short spacings and total power measurements in the cycle 0 observations. This limitation means that we only recover a fraction of the CO luminosity, making it impossible to correctly estimate the mass and energetics of the molecular outflow. That is our goal for cycle 1. With a modest investment of ALMA band 3 we will be able to recover flux in all scales, and measure two a parameter fundamentally related to the evolution of starbursts: the mass, energetics, and ejection mechanism of the molecular gas entrained in the galactic superwind, thought to be the main way to quench massive starbursts. Because we have not yet received the extended configuration observations of dense gas that constitute part of our cycle 0 data, and since projects are not carried from one cycle to the next, we add that request to this proposal. Those observations will allow us to measure the properties of Giant Molecular clouds, thought to drive the high star formation efficiencies in a starburst. They will also provide high resolution data on the aforementioned expanding shell structures. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2015-12-23T15:46:41.000 |
| 1927 | 2015.1.00550.S | 28 | Collision-induced Star Formation in the Milky Way's Central Molecular Zone | Cloud-cloud collision is proposed to be an efficient process to form high-mass stars and their clusters, which may be particularly important in the extremely dense environment of the Milky Way's central molecular zone (CMZ); several localized starburst activities and the argued top-heavy initial mass function within the CMZ may result from frequent cloud-cloud collisions there. The presence and efficiency of the collision-induced star formation (SF) has been an issue of controversy, but we recently discovered a clear signature of collision in the cloud CO-0.30-0.07 in the CMZ; our ALMA/ACA data detected a pair of clumps contacting at a well-defined interface and a linear C18O filament just behind and parallel to the interface. Furthermore, our observations are so far consistent with the primary predictions of the collision-induced SF theory: formation of multiple filamentary structures and core-like features. We propose to conduct a higher-resolution imaging toward the cloud, in order to detect self-gravitating objects capable of forming stars and investigate the core-mass function, and thereby find the first unambiguous evidence for collision-induced SF. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-05-06T16:17:56.000 |
| 1928 | 2016.1.00311.S | 245 | TW Hya as a Chemical Rosetta Stone | The active chemical processes in protoplanetary disks are highly sensitive to the local physical environment. However, our understanding of what physical information molecular lines encode has been previously hindered by limits on sensitivity, where most of our information comes from bright, often optically thick lines at relatively low spatial resolution. We propose a high resolution (10 AU) chemical mapping survey of TW Hya in the rarer isotopologues of the characteristic species, HCN, CN, HCO+, N2H+, CS, and H2CO, to link these key, abundant molecules to underlying physics, providing a "rosetta stone'' for future disk surveys. TW Hya is an ideal target for a chemical mapping survey given the large amount of information (including HD mass) we currently have on its physical structure, along with its nearby proximity and face-on inclination. This suite of observations will be a key resource for interpreting future observations and constraining disk chemical models. To facilitate its use we will make all data products (fits cubes, spectra, radial profiles, etc.) publicly available through a central website for broader access to the community. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-10-22T19:50:22.000 |
| 1929 | 2024.1.01008.S | 0 | Waves of grains: Variations in SED flux density constrain tensile strengths of bodies in the collisional cascade | Dust in debris disks is produced by a "collisional cascade," in which grains are continuously replenished as larger bodies collide and fragment into smaller bodies. The smallest grains are removed u to the "blowout size" at which gravity balances radiation pressure. One prediction of collisional cascade theory that has never been tested observationally is that the small-size cutoff in the collisional cascade should produce waves in the grain size distribution (because grains slightly larger than the blowout size lack collisional partners, but then grains slightly larger than that have an excess of collisional partners, and so on). These waves translate into ripples in the millimeter-wavelength spectral energy distribution, with a characteristic "wavelength" that can diagnose the tensile strengths of the dust in the collisional cascade, a property that is critical for understanding solid body evolution during planet formation but which is extremely difficult to measure outside the solar system. Here we propose to obtain a well-sampled SED of a bright debris disk using ALMA's maximum absolute flux accuracy across 7 bands, spanning more than an order of magnitude in wavelength. | Debris disks | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 1930 | 2021.1.00200.S | 10 | [CI] observations of the Magellanic Supernova Remnant N49 | Atomic carbon line emission (CI) is thought to be a powerful tool for deducing the H2 distribution in galaxies and one that can be as reliable as low-J CO line emission. However, it is not fully understand how the [CI]/[CO] abundance ratio is modified under the environment where cosmic-ray induced and/or shock destructions of CO molecules occur efficiently. We here propose to observe [CI] 3P1-3P0 line emission toward molecular clouds interacting with the Magellanic supernova remnant N49. The edge-on viewed CO clouds revealed by previous ALMA observations provide the best laboratory to investigate variations of [CI]/[CO] through the cosmic-ray induced / shock destructions of CO without any contamination along the line of sight. In short, [CI]/[CO] enhancements via the shock destructions can be seen only inside the SNR boundary, whereas cosmic-ray induced destructions will affect whole the clouds owing to their energy dependent diffusions. The proposed ALMA ACA Band 8 observations at a resolution of ~3 arcsec or ~0.8 pc will allow us to study the spatial variations of [CI]/[CO] in the molecular clouds interacting with the Magellanic supernova remnant for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2023-05-20T09:40:38.000 |
| 1931 | 2019.2.00082.S | 10 | Recovering the flux lost toward VY CMa | VY CMa is the best studied Red Supergiant stars. Its study is shedding light to the mass loss processes which drive the mass ejection in this phase of the massive star evolution, and its ejecta allow us to understand the dust formation in O-rich environments with elemental abundances dominated by the hot-bottom burning and the third dredge up. However, to obtain an accurate view of both the shaping and chemical processes taking place in this star we must recover the flux lost in previous ALMA observations. The aim of this proposal is to complement these ALMA data with short-spacing visibilities to recover the emission from the most extended components and to be able to obtain the most complete understanding of the aforementioned processes. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2021-04-28T11:20:39.000 |
| 1932 | 2018.1.00978.S | 29 | How do supermassive black holes grow? Tracing gas transport in the luminous AGN NGC4593 down to the central 5pc. | We propose to map the circum-nuclear molecular gas distribution, using CO(2-1), in the nearest massive high-accretion rate AGN, NGC4593, at 5 pc spatial resolution. We will test simulation-predictions on a potentially essential gas transport mechanism to fuel supermassive black holes (BHs) in galaxy centers. Gas transport is caused by torques resulting from a (1) high central molecular surface mass density, (2) a lopsided gas distribution, and (3) signature overdense structures as e.g. single armed spirals, from several 100 pc all the way into the sphere of influence of the BHs, and to the accretion disk. NGC4593 is the nearest AGN with a M(BH)~10^7 Msun and accretion rate of several % of Eddington and thus representative of the AGN population responsible for >50% of the BH mass density growth since z=1, and likely beyond. Multiwavelength data exist for this AGN, includin HST and coarse CO from ALMA showing a central single armed dust and gas spiral. ALMA's high spatial resolution now permits, for the first time, a trace of the molecular gas all the way to the BH's sphere of influence (~10 pc), to test this essential but empirically untested secular mechanism for BH growth. | Galactic centres/nuclei | Active galaxies | 2020-11-06T20:10:39.000 |
| 1933 | 2018.1.00443.S | 757 | How is the mass assembled in high-mass star-forming regions? | One of the key problems in Galactic star-formation studies is to understand how the gas flow from the large, parsec scales down to the sub-parsec scales to form massive cores, the birth-place of future massive stars. It has not yet been demonstrated how the high infall rates observed in massive clumps (size of ~1-2 pc) relates to the infall rates in the inner cores (~0.1 pc), and if at the sub-parsec scales they are as high as predicted in some star-formation models. In addition, it is not yet defined if the infall rate changes with the evolution or it stays relatively stationary, leading to different star formation mechanisms. With this proposal we aim to investigate these open problems by measuring the infall rate at the core scales in a sample of clumps selected 1) to show clear evidences of large-scale infall motions in single-dish observations and 2) to be representative of different evolutionary stages. Our setup will also allow us to study the outflow properties and to put them in relation with the observed infall rates at various evolutionary phases. These results will shed light on how the mass is assembled during the earliest phases of massive star formation. | High-mass star formation | ISM and star formation | 2020-01-10T23:49:05.000 |
| 1934 | 2022.1.01531.S | 66 | An Unbiased Survey of Disk Structures and Planet Formation around Very Low-mass Stars in Taurus | High-resolution ALMA images of dust disks reveal that some disks are large and exhibit exquisite substructures, while others are small and may lack substructures. Since most of these are images of disks around 0.5-2 Msun stars, the stellar mass range is insufficient to use as a lever arm for correlations of disk morphology versus stellar mass. We request high resolution (0.05") images of 8 very low-mass (0.1-0.3 Msun) T Tauri disks in a larger sample that also includes 6 archival objects, selected to be unbiased to substructures and mm-brightness, to evaluate the differences in the dust morphology in disks versus stellar mass. The ultimate goal is to understand how the differences at the disk stage relate to differences in the population of exoplanets around very low-mass and solar-mass stars. The sample is complete for disks around M3-M5 stars, with selection criteria for extinction, known binaries and declination. These observations provide an important complement to unbiased, high-resolution surveys of disks around solar-mass stars in Taurus and other nearby regions. | Disks around low-mass stars | Disks and planet formation | 2024-07-04T02:43:03.000 |
| 1935 | 2022.1.01296.S | 5 | First Thermal Imaging of Triton | Triton, the largest known KBO-type body in our solar system, represents (with Pluto) a potentially ubiquitous class of worlds with nitrogen atmospheres controlled by volatile transport, sublimation and condensation, and are therefore strongly coupled to surface temperature. We propose observations of Triton's 350 GHz thermal continuum emission at 28 mas resolution and 0.4 K sensitivity (Band 7, C-8 configuration). Using three well calibrated visits, separated by ~120° longitude, we will (a) accurately measure the disk average brightness temperature, allowing older archival data, including spectral lines of CO and HCN, to be more accurately analyzed, and allowing comparison to and contrast with Pluto, and (b) map variations in thermal emission predicted by new volatile transport modeling, with ~16 independent beams across the disk for each visit. The sensitivity and resolution that only ALMA can achieve will provide high fidelity images of Triton's thermal emission, placing strong constraints on the distribution of ices on the surface, and in turn constraining volatile transport and evolution models of Triton, and more generally icy worlds with nitrogen dominated surfaces. | Solar system - Planetary surfaces, Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2025-02-13T22:12:20.000 |
| 1936 | 2016.A.00013.S | 27 | SEARCHING FOR A KUIPER BELT ANALOG IN PROXIMA CENTAURI WITH ALMA | After our discovery a few months ago of a terrestrial planet in the habitable zone of the closest star, Proxima Centauri (Anglada-Escude et al. 2016), a large effort is being carried out to characterize the planet and the star-planetary system. Our calculations indicate that there are reasonable expectations that Proxima Centauri is surrounded by a compact Kuiper-belt analog with a flux density high enough to be imaged with ALMA. We request DDT observing time in band 6 to attempt its detection with ACA and imaging with the 12-m array. If successful, our observations would provide valuable information on the dynamical history and architecture of the planetary system. They would allow us to determine the orbital inclination and the true mass of the Proxima b planet,and to characterize its debris environment, which would affect its habitability, its prospective direct detection in the optical, and even the feasibility of a visit using microprobes. This project is presented as a DDT, as its expected results would provide immediate and huge scientific impact (while requiring a modest integration time) on a source that is being extensively studied after the recent planet discovery. | Debris disks, Exo-planets | Disks and planet formation | 2017-10-03T18:57:13.000 |
| 1937 | 2019.1.01558.S | 13 | Investigating the Impact of SNR W41's Shock on a Dense Molecular Filament and its Molecular Cores | G23.33-0.30 is a massive molecular filament that is experiencing an ongoing interaction with the shock from SNR W41. This interaction has resulted in an extreme velocity discontinuity in the filament, which hosts at least three molecular cores that reside at the locations of the discontinuities. This proposal seeks to address whether the SNR shock has helped or hindered the formation of stars within this dense filament. Molecular line emission at 30,000 AU spatial scales exhibit extremely turbulent line widths, implying significant nonthermal support against gravity. On the other hand, if the molecular cores are too dense for the shock to penetrate, the virial state of the cores at small spatial scales (~5000 AU) may favor collapse. We will measure the virial parameter of the cores (Mvir/Mcore) at 5000 AU to determine if they can still collapse to form stars. The investigation of dense molecular cores under the impulse of SNR shocks is of vital importance, since it has larger implications for the effect of SNR shocks on the star formation efficiency at Galactic scales. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2021-03-30T18:39:01.000 |
| 1938 | 2016.1.01305.S | 22 | Exploring the Early Stages of Formation of Disks and Outflows in Uneven Close Binary Systems. The Case of SVS 13 | The formation of accretion disks in close (separation < 100 AU) binary systems, and particularly in those where both components show different properties, is poorly understood. Theoretical models have shown that, depending on the mass ratio of the components and the specific angular momentum of the system, a circumstellar disk can be formed around one or both of the components. Under some high angular momentum conditions even a circumbinary disk can be formed. However, very few candidates of young close binary systems have been resolved. A remarkable example is SVS 13, a binary system with a projected separation of 65 AU that has been resolved by the VLA. The observations suggest that one of the components is associated with a circumstellar disk, while the companion is an optically visible star with marginal or absent dust emission. We propose ALMA band 7 line and continuum observations that will allow us to test the role of the different ingredients in the formation of a star-disk-jet system in the presence of a close companion. This scenario is probably more common than the isolated case. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-08-10T06:06:12.000 |
| 1939 | 2019.1.00188.S | 26 | Towards a Strong Foundation for Complex Organic Molecules in Planet Forming Disks | Formation of complex organics starts with H2CO. The origin of this species in planet-forming disks is still a puzzle. To-date, CH3OH has only been found in the gas of one disk, while H2CO is seen in many. Recent studies of H2CO in four disks (TW Hya, DM Tau, DG Tauri, and HD163296) suggest formation both in the gas and on the grains. Strikingly, H2CO abundances increase outside the location of the mm-sized grains. Do grain growth and drift reduce the outer disk's protection against stellar UV, boosting photodesorption of CO ice, its embedded H2CO, and fragments of CH3OH leading to H2CO formation? Recent continuum and CO data of three more disks (AS209, IM Lup, and HD169142) allow doubling of the sample in which to explore this hypothesis. We propose H2CO 312-211 observations of these disks to study the radial distribution of H2CO and its relation to the mm-sized dust. Together with lines of CN (UV tracer) and C3H+ (hydrocarbon-chemistry tracer), this allows a direct test whether H2CO probes non-thermal desorption of CO/H2CO/CH3OH ices. Analysis of our data will be supported by thermochemical modeling and laboratory measurements of H2CO photodesorption yields. | Disks around low-mass stars | Disks and planet formation | 2021-07-02T15:25:36.000 |
| 1940 | 2016.1.00320.S | 62 | Surveying the Seeds of Star Formation: Starless Cores in Aquila | Starless cores represent the initial conditions for the next generation of stars. The degree of substructure in these cores is directly linked to core formation processes and stellar multiplicity. We have conducted ALMA surveys of starless cores in Chamaeleon I (Cycle 1), Ophiuchus (Cycle 2), and Orion B North (Cycle 3). We find evidence for both starless core fragmentation and hidden protostars in the Ophiuchus sample, and have used nondetections in the Chamaeleon I sample to constrain the evolutionary stage of this cloud's starless core population. We find that fragmentation is biased toward the most unstable starless cores that are rare in the clouds targeted to date. As such, the statistics on starless core fragmentation remain poor. Here we extend our survey to the Aquila molecular cloud. We target the 100 most unstable starless cores in this cloud with Band 3 continuum and CO observations, increasing our total sample of unstable starless cores by a factor of five. With these data we will fully determine the fraction of cores harboring hidden protostars, the timescales of fragmentation, and the role of turbulent fragmentation in the formation of multiple systems. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-08-10T22:06:06.000 |
| 1941 | 2011.0.00003.E | 0 | Single quasar observations over tens of minutes or longer to determine the properties of atmospheric delay variation over baselines up to 15 km | ALMA engineering data release. | 2018-07-10T12:50:53.000 | ||
| 1942 | 2021.1.00342.S | 16 | Searching for H2D+ in the circumbinary disk surrounding GGTau A | H2D+ has been proven to be among the best tracers of cold, dense and CO-depleted mid-plane of protoplanetary disks where planet formation is expected to occur. In contrast to the generally agreed importance of H2D+, so far all attempts to detect this key molecule in a protoplanetary disk have failed. We propose a very deep search for the 372.421 GHz (1(1,0)-1(1,1)) line of ortho-H2D+ and selected a very promising object for this search, the massive (~0.12 Solar Mass) and cold (~14 K at 200 AU) outer circumbinary disk surrounding the nearby low-mass star GG Tau A. Our disk modeling shows that H2D+ can be detected in a classical regime of cosmic ray ionization (~10^-17 s^-1) in about 2.6 hours of observing time. The first detection of H2D+ emission in a protoplanetary disk would be a great achievement and would pave the way for a better understanding of the gas properties in the mid-plane of protoplanetary disks. We should note that even a non-detection will significantly improve our understanding of the properties of these planet-forming regions, especially it will challenge our understanding of the ionization structure and the basics of chemical processes in the disk mid-plane. | Astrochemistry | ISM and star formation | 2024-02-01T19:01:56.000 |
| 1943 | 2016.1.00856.S | 13 | The complex interplay between gas accretion and stellar feedbacks in primordial galaxies | We have observed the [CII] emission in two normal protogalaxies, with SFR~6 Msun/yr at z>7. For the galaxy with the deepest observation we detect [CII] emission at redshift z=7.107, fully consistent with the Lyalpha redshift, but spatially offset by 0.7"(4 kpc) from the optical emission (Maiolino et al.2015). These results support expectations from recent models that molecular clouds in the central parts of primordial galaxies are rapidly disrupted by stellar feedback. As a result, [CII] emission mostly arises from more external accreting clumps of neutral gas. Cycle 2 [OIII] observations support that most of the gas contained in the galaxy is swept away from feedback mechanism. We detect three [OIII] clumps within a radius of 15 kpc from the Lyalpha emitters. However the low sensitivity of [CII] and [OIII] observations is no sufficient to map the distribution of these clumps around the star-forming galaxy as expected by models. We propose deeper [OIII] and [CII] observations in Cycle 4. By reaching a sensitivity 2x higher than previous observations, we will map in detail the distribution of the accreting gas clumps and will provide information on the gas accretion rate. | Galaxy structure & evolution | Galaxy evolution | 2019-01-05T13:31:10.000 |
| 1944 | 2016.1.00115.S | 3 | Disentangle the polarization mechanims between magnetic field and self-scattering | We propose to observe the polarization of the circumstellar disk around HL Tau to determine the polarization mechanism of whether the grain alignment with magnetic fields or the self-scattering of thermal dust emission. The previous observations of polarization of the HL Tau disk with SMA and CARMA can be explained by either of the two mechanisms. We focus on the difference in the wavelength dependence; the polarization degree does not so much depend on the observed wavelengths if the mechanism is the magnetic field although the polarization degree strongly depends on the wavelengths if it is the self-scattering. We modeled the wavelength dependence and found that combining the upcoming archival data of Band 7 and this proposing data of Band 3, we can clearly distinguish the mechanisms even in the case of non-detection. This observation will determine the basic interpretation of the mm-wave polarization of protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2018-01-27T16:39:52.000 |
| 1945 | 2013.1.00487.S | 2 | Characterizing the Circum-Planetary Disk of GSC 6214-210 b with ALMA | Circum-planetary disks are natural outcomes of giant planet formation but are observationally difficult to study. Fortunately, a handful of wide-separation planetary-mass companions (PMCs) below 15 Mjup have recently been discovered from direct imaging planet searches, enabling a detailed look at the atmospheres and environments of young gas giants for the first time. We propose ALMA 870 um continuum observations of the 14 +/- 2 Mjup companion GSC 6214-210 b, the only young (5-10 Myr), wide-separation (330 AU, or 2.2") PMC known to harbor a circum-planetry disk based on accretion activity and thermal IR excess. Planet scattering will severely truncate these disks, so measuring the dust mass for GSC 6214-210 b will allow us to discriminate in situ formation via either disk instability or turbulent fragmentation versus dynamical scattering to a wide orbit following formation closer in. Our 5-sigma detection goal of 1.8 Lunar masses can be achieved in 11 min of on-source integration time (41 min total) with ALMA. Altogether, these observations will provide the first insight into the origin of the growing population of gas giants being found on extreme orbits beyond 100 AU. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2015-11-11T11:44:51.000 |
| 1946 | 2013.1.00376.S | 3 | HCN emission: a diagnostic of Enceladus' cryovolcanic activity and torus dynamics | The Cassini mission has discovered active cryo-volcanism on Saturn's satellite Enceladus. Localized fractures with enhanced temperatures are the sources of active plumes rich in gas and icy grains. Plume gases are dominated by water but contain several other compounds (NH3, CO2, HCN…). The presence of liquid water beneath the surface and powering the cryo-volcanism is advocated for, but no single mechanism appears to be able to explain in detail the currently observed composition. Gases and grains escaping Enceladus populate rings of gases (the Enceladus torus) and particles (Saturn's E-ring). Models indicate that the spatial, vertical and velocity structure of the torus is determined by source rates as well as a variety of physical processes, including neutral-neutral collisions. Our observations with Herschel have permitted the first direct detection of H2O in the torus, but at a low spatial resolution (13"). We propose to use ALMA to search for HCN emission in the torus in order to (i) determine the HCN abundance in the plumes and constrain their origin (ii) map the HCN emission in the torus at a much improved resolution of ~4" to constrain torus structure and kinematics. | Solar system - Planetary atmospheres, Solar system - Planetary surfaces | Solar system | 2016-06-16T20:48:03.000 |
| 1947 | 2019.1.01181.S | 60 | Understanding the origin of the nuclear emission in radio-quiet AGN - A simultaneous 100GHz/X-ray monitoring of IC 4329A | To understand the origin of the nuclear radio emission in radio-quiet AGN, and to test whether it is produced in the same region that creates the X-ray radiation (the corona), we will study the mm/X-ray variability of the brightest unobscured AGN in the southern sky. Using band 3 we will monitor IC 4329A, observing it once per day over ten consecutive days. The unique resolution capabilities of ALMA will allow us to probe physical scales of 15-36 pc, so that we will be able to exclude contamination from the host galaxy, and to avoid dilution of the coronal flux. These observations will be carried out simultaneously with X-ray monitoring, using the new NASA monitor NICER, which provides unprecedented sensitivity in the 0.3-5 keV band. The simultaneous NICER monitoring of the source has already been approved. This would be the first time such monitoring is carried out, and the detection of correlated mm/X-ray variability would be crucial proof for a coronal origin of the compact radio emission in radio-quiet AGN. Besides, this would also be fundamental to understand the origin of the X-ray emission, proving, for the first time, that the X-ray corona is magnetically-heated. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-06-22T20:54:30.000 |
| 1948 | 2024.1.00061.S | 0 | Understanding star formation quenching by investigating the gas excitation of high-redshift post-starburst galaxies | Despite decades of investigation, galaxy quenching is a missing piece in galaxy formation and evolution models. Capturing galaxies during their main quenching phase, estimating their molecular gas content and conditions (e.g. excitation) is the key to constrain the processes responsible for the cessation of star formation. We propose to observe the CO(5-4) emission of all the 8 post-starburst (k+a) galaxies at intermediate and high redshift with a secure detection of low-J (J = 2, 3) CO transitions and visible from ALMA. With these observations we will empirically estimate the molecular gas excitation (r53 and r52 ratios) in post-SB galaxies close to their quenching epoch and their obscured SFR. This will allow us to test different quenching scenarios: "gas stabilization" (predicting low r53 and r52 ratios) vs "gas exhaustion" (predicting large r53 and r52 ratios). | Early-type galaxies | Galaxy evolution | 2025-11-12T10:24:15.000 |
| 1949 | 2017.1.01162.S | 22 | A GMC Catalog for the Circumnuclear Disk of Centaurus A | In powerful radio-galaxies the properties of the circumnuclear disks (CND) from hundred parsecs down to the accretion disk are hitherto poorly understood. Centaurus A (Cen A) is by far the nearest (D = 3.8Mpc) and best studied powerful radio galaxy and giant elliptical (Israel 1998). Two of the main characteristic features of this source are (1)the high concentration of gas in the inner few hundreds of parsec forming a CND (Espada et al. 2009), and (2)the radio and X-ray jet/lobe structure which is powered by a putative super massive black hole (SMBH). We have already studied the emission of a whole suite of molecular lines (CO(3-2), CO(6-5), HCO+(4-3), and HCN(4-3)) towards the CND probing different density and temperature regimes and with angular resolutions of about 5 pc (Espada et al. 2017, see Fig. 1). Here we ask for follow-up CO(3-2) observations using the ACA to alleviate the missing flux problem in the 12m array CO(3-2) data, since we estimated that 50% of the flux was lost. By combining our previous data with the new ACA data, we will be able to build an unbiased GMC catalog. Preliminar results suggest that GMC properties are similar to those in our Galactic Center. | Active Galactic Nuclei (AGN)/Quasars (QSO), Giant Molecular Clouds (GMC) properties | Active galaxies | 2019-12-20T00:00:00.000 |
| 1950 | 2015.1.00976.S | 22 | Mapping Jet-ISM Interactions in the Prototypical Microquasar GRS 1915+105 | The relativistic jets of AGN and black hole X-ray binaries (BHXBs) carry a significant amount of energy and matter into their surrounding environment and may be significant sources of feedback. Galactic BHXBs are ideal targets for studying jet-ISM interactions in detail due to their close proximity and rapid timescale evolution. However, unlike AGN, there are only two Galactic BHXBs with confirmed jet-blown bubbles in the ISM. We propose targeting IRAS 19132+1035, the candidate jet-ISM interaction site of the prototypical microquasar GRS 1915+105, to identify a critical third Galactic BHXB with a jet-blown bubble. This will advance our understanding of jet physics and ISM interaction in BHXBs, as well as the use of BHXBs as AGN analogues. With 1 hr of Band 6 ALMA-12 m observations, we will map the CO, H2CO, H(30) alpha, N2D+, and SiO line emission over 1.25 sq. arcmin, providing excellent diagnostics of shock energetics and ISM excitation. By resolving excitation and shock conditions in this region, we will definitively test if IRAS 19132+1035 is a jet-ISM interaction site of GRS 1915+105 and if so calculate the time-averaged jet power of GRS 1915+105 through calorimetry. | Outflows, jets and ionized winds | ISM and star formation | 2017-04-20T04:07:51.000 |
| 1951 | 2022.1.00276.S | 66 | Resolving the Cloud-Cluster Ecosystem in M33 | We propose ALMA observations of the inner disk of M33, over a region which matches a six-band photometric survey conducted by the Hubble Space Telescope. The new HST survey will provide an unmatchable perspective on the cluster population and dust extinction map over a 25 square-kpc region. We will achieve a high quality map of CO(1-0) over the same area with 3" = 12 pc linear resolution, identifying >5000 molecular clouds down to a mass of 2500 Msun. These data will constrain the lifetimes, mass accretion rates, and cluster formation properties of the molecular cloud population. These new results are essential for understanding how the structure of the molecular ISM and how the evolution of clouds controls the effectiveness of stellar feedback. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2025-01-22T17:50:48.000 |
| 1952 | 2023.1.01606.S | 0 | Magnetic Fields in Massive Collapsing Clumps | The importance of magnetic fields (B-fields) in the high-mass star formation (HMSF) is a long-standing question. However, there is a lack of statistically significant results down to the sub-core scale, particularly between the envelope and the disk. Massive collapsing clumps, which have large-scale infall and highly dynamic process, are privileged sample to study the role of magnetic fields in HMSF. Based on a sucessful pilot ALMA non-polarization observations, we propose to observe 17 massive collapsing clumps with 700-1500 au resolution in both continuum and lines at polarization mode. We expect to achieve: 1) more than 40 independent measurement of polarization per field; 2) sufficient strong H13CO+ and HN13C lines to study gas kinematics down to sub-core scale. With such a large sample, we will answer: 1) what's role of B-fields in mass assembly; 2) how do B-fields influence the fragmentation; 3) can massive prestellar cores exist in a magnetized protocluster environment? | High-mass star formation | ISM and star formation | 2025-08-01T19:38:23.000 |
| 1953 | 2023.1.00646.S | 0 | Magnetic fields of starless cores in IRDC G035.39-00.33 | The magnetic fields of starless cores are key to constrain the initial conditions of star formation process. Unlike protostellar cores, the polarized intensity of starless cores is hard to detect since starless cores lack embedded bright continuum sources; thus the dust polarization of starless cores has rarely been studied. IRDC G035.39-00.33 is a quiescent massive star-forming region and it is likely at very early evolutionary stage. We propose to observe the mean B-field directions of five brightest compact embedded cores toward IRDC G035.39-00.33 in Band 6, including three starless cores and two protostellar cores. With our results, we could examine if the initial core-scale B-fields are aligned with the filament-scale B-field observed with JCMT/POL2, which is essential to study if B-fields regulate core formation. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-10-02T01:14:00.000 |
| 1954 | 2021.1.00067.S | 144 | Resolving the 870 m dust emission in high-redshift SMGs: Fuelling starbursts through bars and rings? | ALMA observations of high-redshift star forming galaxies have revealed compact (~2-3kpc FWHM) dusty cores in everything from main sequence galaxies to the brightest SMGs. Despite their prevalence and their implications for bulge growth and morphological transformation, very little is known about the small scale structure of the star formation within the ISM of these galaxies. A recent pilot study of six ALMA-SMGs at 0.08'' resolution (~500pc) revealed structures with sizes of 0.5-1 kpc embedded within (dominant) exponential dust disks. The dust morphologies show clear curvature and/or clumps bracketing elongated nuclear emission, suggestive of bars, star-forming rings and spiral arms. Here, we propose to build on this pilot study and measure the dust continuum morphologies for a complete sample of nineteen bright (>8mJy) SMGs at z=2-3.5. We will split the sample by star formation rate to determine how the strength of the central starburst correlates with morphology and bar/ring strength. This sub-kpc census is necessary to determine the distribution of the star formation in these dusty cores, which may be a ubiquitous phase of early massive galaxy growth. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2023-09-01T09:39:57.000 |
| 1955 | 2017.1.01168.S | 36 | Spatially resolved molecular spectroscopy of the most extreme star forming galaxy in the Epoch of Reionization | We propose to spatially resolve molecular lines in the most massive star forming galaxy discovered in the epoch of reionization (EoR). SPT0311-58 was discovered via its thermal dust continuum with the South Pole Telescope. We obtained a spectroscopic redshift of z=6.9 with ALMA in Cy 3. In Cy 4 we obtained high resolution imaging in [CII] and [OIII], demonstrating that the source is only modestly gravitational lensed and is comprised of two distinct galaxies separates by 8 kpc. The presence of such a massive system at this early time is an unexpected and fortuitous discovery. We now propose to image the system in multiple CO line transitions, water, and neutral carbon. These ALMA observations will provide key and unprecedented insights into the molecular composition of this system, allowing us to directly constrain the ISM properties of an intensely star forming and interacting pair of galaxies in the EoR. We have arranged these observations to be maximally efficient, with 0.3 resolution and 5 different line transitions robustly detected in just 13 hours of observing time with B3 and B4. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-01-26T01:00:44.000 |
| 1956 | 2019.1.01710.S | 10 | The birth of a protostar: nascent outflow and envelope kinematics at the earliest time | High-resolution observations of extremely young sources in which the initial conditions are preserved can serve as a link between observations of pre-stellar collapsing cores and Class 0 protostars, improving our understanding of the onset of star formation. The L1451-mm core is an exceptional ALMA laboratory to study a protostar and its environment close to its birth. This source drives one of the most compact CO outflows known, with lobes unresolved at 1" scales (~ 300 au) and no high-velocity counterpart. The dense gas shows no signs of central heating in current observations (~3.5", 1000 au). We propose Band 6 molecular line and continuum observations with 0.36" resolution (~100 au) to: 1) resolve for the first time the structure and kinematics of the outflow and constrain its origin and launching mechanism; 2) determine the impact of the outflow on the envelope at a very early evolutionary stage; and 3) study the kinematics of the dense gas surrounding the central source at scales of the transition between envelope and disk. The proposed observations are a robust test to our current theoretical understanding of the collapse of dense cores and the birth of protostars. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2023-06-28T16:40:51.000 |
| 1957 | 2013.1.00305.S | 17 | Build-up of protoplanetary core-accretion in the dust trap of HD142527 | According to recent theoretical progress, the clearing of the protoplanetary cavity by an accreting gaseous giant should lead to apressure enhancement in the outer rim of the gap, shaped into a horseshoe, where dust grains are trapped, and where temperatures drop. Core-accretion may occur efficiently in these dust traps, leading to second generation planet formation. In this scenario the origin of the outer disk pressure enhancement is due to on-going dynamical clearing. Inside the gap, the first generation giant(s) channel outer disk material across the gap, thus feeding stellar accretion. The HD142527 disk is an ideal laboratory to test the scenario of second generation core accretion at large stellocentric radii. It hosts the best-studied horse-shoe and the largest cavity in a face-on orientation, in which gas kinematics have been resolved in Cycle0. We aim to 1- measure grain growth inside the dust trap of HD142527, 2- measure physical conditions and kinematics in the dust trap, and 3- understand the cavity dynamics to ascertain the physical origin of the gap-crossing flows. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2016-09-04T23:20:14.000 |
| 1958 | 2019.1.01222.S | 7 | Shadows, streamers, spirals and planets: A deep characterization of the circumbinary disk around GG Tau A | A substantial fraction of stars form in binary systems, implying that circumbinary disks and - thus circumbinary planets - could be frequent. The conditions for planet formation are expected to be very different around binary stars, and a detailed understanding of binary-disk interaction is key in predicting and understanding the end-state of properties of (circum-)binary systems. Our recent SPHERE observations of the emblematic circumbinary system GG Tau A at 50 mas resolution reveals the presence of numerous shadows, streamers and spirals - direct imprints of binary-disk interactions and possible planet formation. We propose to obtain ALMA Band 7 observations at high angular resolution (50 mas) to 1) detect and characterize the circumstellar disks around GG Tau Aa and Ab, 2) detect the counterparts of the streamers and spirals in the dust continuum and 12CO, and 3) search for signatures of ongoing planet formation. Our combined multi-wavelength study in scattered light, gas and dust will allow us to characterize binary-disk interactions at unprecedented detail and constrain the reservoir and occurrence of planetary formation in a multiple system. | Disks around low-mass stars | Disks and planet formation | 2022-10-31T21:00:06.000 |
| 1959 | 2017.1.00979.S | 20 | Disk eccentricity and circumplanetary dust in the HD 106906 system | HD 106906 is the only system known to host an external planetary-mass companion dynamically perturbing a directly imaged debris disk. The system provides a unique opportunity to study dynamical mechanisms that shape the architectures of planetary systems. The origin of the companion is not yet clear, but ALMA observations interpreted in the context of dynamical models can disentangle a planetary ejection scenario from an in situ formation mechanism, with implications for an entire class of large-separation companions. We propose to image the disk at 0.3" resolution in Band 7 in order to test a prediction about the distribution of parent bodies based on the scattered light images. By measuring the eccentricity of the parent body belt through a combination of apo- to pericenter flux ratio and stellocentric offset, we will prove or disprove an in situ formation scenario. Based on the infrared colors and sensitivity of our observation, it is also extremely likely that we will detect a circumplanetary disk around the companion, providing further support for an in situ formation scenario and identifying only the second circumplanetary disk imaged at mm wavelengths. | Debris disks | Disks and planet formation | 2019-10-01T20:45:07.000 |
| 1960 | 2017.1.01553.S | 67 | Interplay between the Orion A South (OMC-4) filament and dense cores therein | We propose to map the quiescent filament in Orion A South (OMC-4) with 3-mm and 1-mm continuum as well as the dense molecular tracers including N2H+, HNC and HC3N, aiming to reveal the detailed structures and kinematic features of the V-shaped filament of OMC-4, to resolve the dense clumps therein into individual cores of Jeans Scale, and to determine the dynamical properties and the instabilities status of the cores. Eventually, these results would help to understanding several fundamental properties and characters of the filament structures and there roles in mass aggregation and initiating the star formation. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-01-03T15:43:25.000 |
| 1961 | 2015.1.00306.S | 33 | The earliest stages of molecular outflow activity from the young protostar Lupus 3 MMS | We propose Band 3 and Band 6 observations of CO isotopologues and continuum for the class 0 source Lupus 3 MMS. Consistent observations in two bands, performed with the same angular- and spectral-resolution, allow a comprehensive study of the morphology, kinematics, and temperature structure of the outflow and its driving protostellar source. We will map the entire outflow using the 12m array and the ACA, studying the collimated and cavity structures of the outflow. This is a particularly interesting source because accretion has only very recently begun, and we will use its outflow as a proxy for the accretion history, therefore providing a case study for the very earliest stages of the low-mass star formation process. | Outflows, jets and ionized winds | ISM and star formation | 2018-03-31T17:32:34.000 |
| 1962 | 2015.A.00023.S | 1 | Measuring the Size of a New Dwarf Planet Candidate | We seek to accurately measure the size of a new dwarf planet candidate discovered by the Dark Energy Survey (DES). The object is currently the second most distant known TNO at 92.5 AU with an r-band magnitude of 23.2, suggesting that its diameter may be >1000 km. An object of this size would be comparable to the largest main belt asteroid, Ceres, or Pluto's moon Charon. Optical measurements alone cannot determine the candidate's size because its albedo is unknown. TNOs are known to exhibit a wide range of albedos, from a dark, organic-rich 5% to icy 80% or more, meaning our candidate may range in size from 350-1200km. We propose to use ALMA to study the thermal emission of our candidate to obtain a more accurate size measurement and potentially establish it among the five largest known minor bodies in the solar system. This object, if found to have a low albedo and large diameter, would signal a larger population of 1000-km-class TNOs. Measurement of its size will also enable a calculation of its albedo/composition. Six hours of integration time will result in a robust detection of our dwarf planet candidate for even our smallest size estimate. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2017-03-16T17:11:49.000 |
| 1963 | 2017.1.01532.S | 19 | The chaotic formation of a massive galaxy at z=6.6 | High redshift quasars are thought to be hosted by massive and luminous galaxies. One of the most stunning examples is the bright quasar host J0305-3150 at z=6.6. Our ALMA Cycle 1 and 2 observations of the [CII], CO(6-5) and CO(7-6) lines and the underlying continuum revealed a luminous source with a very high star-formation rate and a massive cold gas reservoir. High-resolution (~0.2, 1kpc) follow-up of the [CII] line and the underlying continuum in Cycle 3 revealed a spectacular morphology of the ISM, with kinematics inconsistent with simple rotation. The brightness of the CO lines (observable in one setup) now allows us to resolve the kinematics/morphology of the molecular gas in this quasar. This will be the first spatially resolved CO/H2 map of a z>6.5 galaxy. The comparison of the [CII] and CO kinematics and morphologies will provide spatially resolved constraints on the characteristics of the ISM (densities, radiation field) of this unique system. We also propose to push the resolution of the [CII]/dust setup further, to an unprecedented 0.05" (or 250pc) to finally resolve the bright continuum emission that is coincident with the central accreting supermassive black hole. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-12-14T01:26:04.000 |
| 1964 | 2015.1.00167.S | 115 | Spatially resolved wideband spectroscopy in ULIRG obscured nuclei II | Molecular spectroscopy is shown to be a good probe of the heating mechanism in heavily obscured nuclei. Though extensively observed, the closest ULIRG prototype Arp220 continues to surprise us at high resolution mm/submm (Tunnard+2015,Rangwala+2015,Aalto+2015). Our still ongoing Cycle 1 project to explore the chemistry of Arp220 at high resolution reached the confusion limit and isolated the chemistry of the two nuclei. First results are being published. We unveiled the rich chemistry of each nucleus, with differences both to local galaxies and between nuclei. The faintest species (some complex ones) are emitted in regions with different excitation conditions. Thus, a full picture of the physical morphology of its two nuclei requires more accurate determination of molecular abundances and of the excitation conditions of each detected species. This motivates us to extend the survey towards the lower frequencies to increase the number of transitions and energy ranges covered. This survey will provide a basic tamplete, not only for future studies of Arp220 but for all kinds of IR luminous galaxies near and far. If Band 6 setups are observed in Cycle 2 the time request will be 6.4h. | Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2017-12-16T11:55:42.000 |
| 1965 | 2022.1.01626.S | 40 | Non-star-forming molecular gas in intra-cluster multiphase orphan cloud | We propose to map CO emission in the recently discovered multiphase gas "orphan" cloud which is far away (> 80 kpc) from any galaxy. It is projected about 800 kpc from the center of the nearby galaxy cluster Abell 1367. It is the first and still the only known isolated "intra-cluster" cloud detected in X-ray, H-alpha and CO emission. The presence of abundant hot, warm and cold medium suggests a rich physics of gas mixing with the surrounding intra-cluster medium (ICM) is taking place. Recent MUSE IFU observations revealed a complex H-alpha morphology and a velocity gradient of 200 km/s. New IRAM 30-m observations of two regions in the cloud found 2e8 Msolar of molecular gas, constituting about 10% of the cloud's total mass budget. Yet, only a very small amount of star formation was found in the cloud, indicating that the conversion of the molecular gas to stars is extremely inefficient. The cloud likely represents a late evolutionary product of a gas stripping event of a massive infalling galaxy. With the A1367 orphan cloud, we have a unique opportunity to study in detail stripped ISM far from its parent galaxy that has developed into an ICM inhomogeneity. | Galaxy groups and clusters | Cosmology | 2024-02-18T22:30:54.000 |
| 1966 | 2016.2.00088.S | 17 | Measuring the CO envelope of OH26.5 : the CO photodissociation radius | We plan to observe OH26.5+0.6 using the ACA in order to recover the large-scale flux which has been resolved out in our observations of the 12 metre-array configuration. This will be used to establish the CO envelope size which is directly tied to the gas density and to study past mass loss behaviour of the star at the tip of the asymptotic giant branch. These stars are important contributors of dust and heavy elements as they lose most of their mass via cool, slow winds, forming a circumstellar envelope of molecules and dust around the central star. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-08-14T17:48:01.000 |
| 1967 | 2011.0.00921.S | 0 | Physical conditions for planet formation: the case of T Cha | T Cha is a young star surrounded by a transitional disk in which a gap of 15AU has been detected. High angular observations obtained with VLT/NACO allowed us to detect an extremely red substellar companion located within the gap of the disc. At the time of writting this proposal we have obtained NACO second epoch observations that confirmed that the star and its companion are bound. Therefore, for the first time we are witnessing in-situ formation of a substellar object, probably a young planet, within the disk of T Cha. We propose to use the unique capabilities of ALMA to (i) derive the kinematics and properties of the gaseous disk, measure the dust mass, and compare the mass and morphology of these two components (dust and gas) to provide key constrains to understand the physics that govern the early stages of planetary formation, and (ii) obtain the dynamical mass of the central object to properly characterize the binary system and provide important clues about its formation mechanism. | Disks around low-mass stars | Disks and planet formation | 2013-12-28T08:12:05.000 |
| 1968 | 2012.1.00377.S | 34 | Fire and Wind in Compton-thick Monster: The Case of NGC 4418 | [This project will take ~125 min of 12m-array time on the galaxy. See Tech. Justification.] We propose to study a putative Compton-thick AGN and its molecular outflow in the luminous infrared galaxy NGC 4418 to reveal the true nature and evolutionary path of this elusive galaxy nucleus. For the fiery hot but dust-enshrouded nucleus we will use the new 1 km baseline to measure the size and surface temperature of its continuum core, i.e., dust photosphere. We will then obtain the bolometric luminosity from within the central few 10 pc using the Stefan-Boltzmann law. We will also measure the dynamical mass of the core using molecular lines including bright CO(3–2). The luminosity-to-mass ratio and luminosity density measured this way will constrain the nature of the hidden nucleus because, for example, stars cannot have as high an L/M ratio as an accreting black hole. Our SMA data suggest that the nucleus of NGC 4418 is an ideal target for this new approach and for Cycle 1 ALMA. We will also map in CO(2–1) a multi-kpc superwind that we found emanating from the nucleus. We will measure the distribution and velocity field of molecular gas in the outflow to determine the mass outflow rate and kinematical age. NGC 4418 is among the nearest galaxies that have both a highly Compton-thick nucleus and a giant outflow. Thus the proposed observations will become an archetype of ALMA studies on galaxies in rapid transition from the buried infrared-luminous phase to optically visible Seyfert/quasars. The AGN/starburst feedback widely regarded important in galaxy evolution is in full action here for detailed analysis. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2016-09-30T04:55:11.000 |
| 1969 | 2018.1.00295.S | 78 | FIR [O III] emission from a candidate z ~ 10 galaxy | We propose ALMA Band 7 observations of a secure candidate for a z ~ 10.0 Lyman break galaxy to detect the [O III] 88 micron line. Given the extremely-high brightness of the [O III] line, which has been demonstrated by our recent ALMA detections of the [O III] line in z = 7-9 LBGs, the proposed study allows us to not only determine the spectroscopic redshift of the z ~ 10.0 candidate LBG, but also characterize metal enrichment for the first time when the age of the Universe was only 480 Myr. The observations will detect 960 micron dust continuum emission even in the case of non-detection of the line, which places a stringent limit on formation process of dust grains in the primordial Universe. ALMA will therefore provide a very unique opportunity before the JWST era that allows a tantalizing glimpse into the earliest production of heavy elements. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-12-11T12:16:10.000 |
| 1970 | 2018.1.01496.S | 134 | Phosphorus-bearing molecules towards a Solar-system precursor | The study of the chemical composition of planet-forming regions is a fundamental step to understand how prebiotic chemistry could proceed in the early Earth. Phosphorus compounds, and in particular the P-O chemical bond, play a key role in the formation large biomolecules such as DNA. We have recently detected PO for the first time towards massive star-forming regions, but the detection towards a Solar-system precursor at protoplanetary disk scales (< 100 au) is still lacking. This project proposes to detect PO (and also PN) towards the Solar-like protostellar system IRAS16293-2422 at high spatial resolution (0.35 au). This will allow us to disentangle if the P-bearing emission previously detected with a single-dish telescope arises from the centrifugal barrier (~50 au), the surrounding envelope (50-200 au) or from more extended gas associated molecular outflows (>200 au). This will put important constraints about the formation of P-bearing molecules. The molecular abundances of PO and PN will be compared with those we have recently derived in the comet 67P to investigate if there is a Phosphorus chemical thread. | Low-mass star formation, Astrochemistry | ISM and star formation | 2021-01-08T00:05:29.000 |
| 1971 | 2013.1.00091.S | 7 | Are the azimuthal asymmetries of transition disks particle traps? | Circumstellar disks around young stars are known to be the birthplaces of planets. Planet formation starts with the coagulation of dust particles to larger dust aggregates. However, after many decades of research it is still an enigma how Nature manages to overcome the 'meter size barrier'. At sizes beyond about 0.1 millimetre at ~50AU distances, the particles acquire high radial drift velocities and high collision speeds, leading to destruction and loss. In recent years the concept of "particle traps" has gained popularity as a possible solution to this problem: Large scale pressure bumps such as vortices can attract and trap dust particles, and provide a calm localised environment where dust growth proceeds very effectively. This idea can be tested with ALMA in Cycle 2. Our program aims to investigate the process of dust trapping in the transition disks around SR24S and LkHa330. With two ALMA observations per source at 345GHz (Band 7) and at 230GHz (Band 6), we will test the theoretical predictions for the azimuthal profile of the spectral index and the gas density distributions. A confirmation would lend credence to the notion that planetesimals form in very localised 'hotspots' | Exo-planets | Disks and planet formation | 2016-10-09T17:44:10.000 |
| 1972 | 2023.1.00461.S | 0 | Unveiling the contribution of dusty star-forming galaxies to the cosmic metal enrichment | We propose to observe three dusty star-forming galaxies in the MUSE Ultra Deep Field with ALMA to determine their precise redshift, and to unveil their contribution to the cosmic enrichment. With 300 hours of MUSE and HST imaging and spectroscopy, the MUDF provides an extremely deep survey of the unobscured galaxy population in a strategic field where a z~3.22 quasar pair enables a unique study of how dust-free galaxies correlate with the intergalactic gas. ALMA has mapped this field by uncovering seven dusty star-forming galaxies, three of which are associated to quasar absorbers. Other three sources - corresponding to 40% of the sample - remain undetected in the deep MUSE data thus leaving open questions on galaxy-IGM connections. We propose band 3 spectral scans to target the CO(3-2) line (and the underlying 3-mm dust continuum), to constrain the redshifts of the remaining three dusty galaxies. The proposed observations will complete our view of the connection between dusty star-forming galaxies and the enriched gas detected in absorption and will shed light on how galaxies of different physical proprerties contribute to the cosmic metal enrichment in different environments. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2025-03-11T19:22:12.000 |
| 1973 | 2021.1.01179.S | 20 | The Cluster Formation and Evolution Cycle of a Starburst-Driven Nuclear Outflow: The Case of NGC 7552 | The complex interplay between feedback-driven outflows and their host galaxy ISM remains largely unconstrained at the relevant physical scales of individual star clusters. Here we propose to observe the nuclear starburst region of the nearby (D_L = 22 Mpc) luminous infrared galaxy (LIRG: LIR > 10^11 Lsun) NGC 7552, to measure the properties of ~20 embedded star clusters suggested from previous ATCA, SMA, and SINFONI imaging. As the only starbust LIRG for which ALMA can resolve individual clusters (0.1" ~ 10pc), NGC 7552 represents the best laboratory to study the earliest phases of cluster formation and evolution in a truly extreme environment. Observations of the H40/42 recombination lines, CO (3-2) emission, and the continuum in Bands 3 and 7 allow us to estimate the gas mass, dust opacity, stellar content, and dynamical state of each massive cluster. The main question we will then address is: How do the derived cluster properties, and their inferred cluster formation efficiencies, change in this extreme starburst environment, and what is the impact of different types of feedback occurring in the youngest clusters still deeply enshrouded in their natal cocoons. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2023-06-01T15:55:55.000 |
| 1974 | 2019.1.01068.S | 5 | The Hero Twins?: Keplerian disk pairs in the heart of two massive protoclusters | We have recently discovered two remarkable systems, each containing two candidate high-mass protostellar disks separated by <6000 AU. The existence of such closely clustered disks represents an important new constraint for models of massive star formation: the requirement to produce multiple high-mass protostars with disks within the scale of an individual prestellar core (0.1 pc). More remarkably, in one system the disks appear to be misaligned by 180 degrees, posing a challenge to the canonical picture of disk formation as a consequence of the orderly collapse of a rotating core. We propose to image these systems at 0.09" (120 AU) resolution in disk-tracing lines at 1.3 and 2.1 mm (including SO2 and multiple ladders of v=0 and vibrationally excited CH3CN) to resolve the extent and kinematics of the candidate disks and so directly measure the masses of the central protostars. By measuring protostellar masses and disk masses and sizes in these highly clustered environments, we will provide new quantitative benchmarks for massive star formation models. | High-mass star formation | ISM and star formation | 2022-10-22T17:47:42.000 |
| 1975 | 2017.1.00139.S | 73 | The interstellar medium in the first Gyr of the Universe | The first massive galaxies formed in intense bursts of star formation in the first Gyr of the universe (z>6). So far, virtually all highly star-forming galaxies known at z>6 are quasar host galaxies. The interpretation of their phenomenology is hindered by the unknown effect of the bright, central nucleus on the interstellar medium (ISM). Recently, via our ALMA Cycle 3 survey of [CII] in z>6 quasars, we serendipitously discovered 4 highly star-forming galaxies adjacent to quasars, but which show no indication of a central accreting massive black hole (Decarli et al 2017a, Nature). This offers the outstanding opportunity to study the interplay between gas and star formation, without the complication of the additional nuclear emission. We propose a multi-line study of the ISM in two of these quasar companions, as well as the quasars themselves, targeting 11 key ISM tracers with only 4 frequency settings. Our results will allow us to study the interplay between various gas phases, star formation, and the impact of nuclear activity at the dawn of galaxy formation. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-06-07T11:08:53.000 |
| 1976 | 2018.1.01056.S | 11 | Understanding column densities toward massive gas flows in gas-rich central galaxies | ALMA has shown that radio AGN drive massive flows of molecular gas in central cluster galaxies. The molecular gas has likely condensed from low entropy gas in the cluster core that has been lifted by X-ray cavities. However, the uplifted masses rival the maximum mass that the cavities can lift, implying a remarkably efficient coupling. Measurements of column density in these massive molecular flows are required to accurately calibrate the uplifted mass, instead of relying on the Galactic CO-to-H2 conversion. We propose to test this by mapping the distribution of molecular gas in Zw3146 using every CO transition up to CO(4-3). Zw3146 is a prime candidate to address this issue as it is both extremely gas-rich and is experiencing a powerful AGN outburst, making it an ideal candidate for hosting AGN-driven gas flows. It is also one of the few BCGs in which all four low-J CO lines can be observed by ALMA. These observations will allow the column density and CO-to-H2 conversion factor to be measured in both the molecular filaments and the nuclear gas, revealing any spatial variations in gas excitation and molecular mass calibration. This will be the first analysis of its kind in a BCG. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2020-12-13T20:16:48.000 |
| 1977 | 2022.A.00035.S | 14 | Deep Band 1 observations of a planet forming disc, resolving dust rings and detecting molecular emission lines | In the last decade ALMA has revolutionised the study of protoplanetary disks through observations mostly in band 3, 6 and 7. With the expected idle time at low frequencies in the 2023 Long Baseline Campaign, we now propose to repeat this success in the newly incorporated Band 1. We propose to observe HD 163296, a benchmark (and the brightest) system for the community. These observations will be extremely useful for the whole community upon their release. By demonstrating Band 1 capabilities in resolving dust structure and detecting lines from important molecular species, these observations will trigger future high resolution, low frequency ALMA observations that build on this result both in HD163296 and in other disks. | Low-mass star formation | ISM and star formation | 2024-04-11T00:27:35.000 |
| 1978 | 2015.1.01379.S | 17 | Key laboratory for AGN feedback and spheroid formation: a moderately luminous AGN at z ~ 2 | We detected possible gas outflows in star-forming galaxies at z~2--3 hosting hidden AGN activity. These results suggest a causal link between the AGN feedback and the concomitant migration of galaxies to the red sequence (Cimatti et al. 2013, ApJL). We propose an ALMA observation of a representative active galaxy at z~2 in order to detect the molecular gas outflow and understand its role in the scenario of rapid quenching of star formation. ALMA is essential to study directly the cold gas reservoir and penetrate the regions obscuring the AGN. We ask observations of two different CO transitions through two ALMA bands. We will use the CO (3-2) flux (band 3) to obtain a robust estimate of the total gas mass, and the CO (6-5) lines (band 6) to study in depth the properties of the molecular gas outflow. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-07-20T15:57:04.000 |
| 1979 | 2015.1.00581.S | 47 | Spying on our Neighbors: Peering into Low Metallicity Molecular Clouds in the Small Magellanic Cloud | A dominant reservoir of H2 gas faint in CO emerges as metallicity decreases, which alters the structure of molecular clouds and perhaps the sites of star formation. With ALMA, we can reach the resolution necessary to see the structure of photodissociation regions and the transition from ``CO-bright'' to ``CO-faint'' molecular gas for the first time at 1/5 Solar metallicity in the Small Magellanic Cloud. We propose to map four regions in the Southwest Bar of the SMC at high spatial and spectral resolution (1.6" or 0.5 pc scales and ~0.1 km/s) in 12CO, 13CO, and C18O (2-1). We will determine the mass, structure, and kinematics of molecular clouds across a range of environments and explore the effect of the CO-faint molecular gas on low metallicity star formation. With the slew of ancillary data in hand (much collected by the Co-Is in this proposal), including PAHs, [CII], [CI], [NII], [OI], dust continuum, and dust-based H2 maps, we can fully exploit the ALMA observations. This proposal is a resubmission; only ACA observations were completed in Cycle 2 and our science goals require the higher resolution 12m observations. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2017-05-05T21:04:47.000 |
| 1980 | 2018.1.00625.S | 14 | Unveiling Counter Rotation between the Disk and Envelope around the Class I Protostar IRAS 04169+2702 | We propose ALMA observations of the disk and envelope around the Class I protostar IRAS 04169+2702 at a high spatial dynamic range (0.3"-7"; 40-1000 au) in the C18O (3-2) and the other Band 7 lines. Our previous SMA observations of IRAS 04169 found that the 13CO (3-2) and SO (6_5-5_4) emission show a compact (r~200 au) disklike feature with the northwest (blue) to southeast (red) velocity gradient. On the other hand, the C18O (2-1) emission traces a more extended (r~500 au) protostellar envelope with the northwest (red) to southeast (blue) velocity gradient, opposite to that in the inner 13CO and SO emission. The high spatial dynamic range and spectral resolution (= 0.22 km s-1; close to the thermal line width) of ALMA enable us to unveil the origin of this apparent flip of the velocity gradient; i.e., counter rotation between the disk and envelope or gas motions related to turbulences. If there is indeed such a counter rotation, this should be an unique observational evidence for the effect of the magnetic field. From the comparison between the ALMA results and our own theoretical model, we will investigate the effect of the magnetic fields / turbulences on disk formation. | Low-mass star formation | ISM and star formation | 2022-12-24T01:29:30.000 |
| 1981 | 2018.1.00223.S | 77 | Molecular Gas in Twin Galactic Outflows | We propose a CO multi-line study to characterize two types of galactic molecular outflows in a single object, the luminous infrared galaxy NGC 3256. Molecular outflows are prevalent among active galaxies. The feedback through such outflows may affect the wind-driving activities and the host galaxy evolution. Yet the parameters of the observed outflows are still rather uncertain. This is because the physical conditions and hence line emissivities are poorly constrained for the outflowing gas. Moreover, they may vary with the types of galactic outflows (e.g., driven by starburst or AGN). In Cycle 0, we found twin molecular outflows in NGC 3256; a starburst-driven wind and an AGN-driven jet. The latter is the most spectacular molecular jet from a galaxy nucleus. We aim at the following with our new observations. 1) to determine the CO excitation in both outflows and improve their mass and outflow parameters 2) to resolve the molecular jet and the outflow-driving merger nuclei to 20 pc scales 3) to obtain the full extent of the outflows in space and velocity We will improve the resolution and sensitivity of our previous observations by factors of 3-6 to achieve these goals. | Outflows, jets, feedback | Active galaxies | 2019-12-06T17:53:55.000 |
| 1982 | 2012.1.00391.S | 0 | AGN feedback at high-z: OH molecular outflows in two high-z QSOs | In the last few years our group has made significant progress in the study of large scale galaxy outflows and their effects on the properties of their host galaxies. By observing with the Herschel satellite the OH 119 micron doublet, we have identified in the form of high-velocity P-Cygni line profiles the presence of strong molecular outflows in a large sample of local ultraluminous infrared galaxies (ULIRGs), PG QSOs and low luminosity AGNs. In some of these objects the inferred molecular mass outflow rates are several times larger than their current star formation rates, and, if maintained, could expel the total molecular gas content of the galaxy in ~10^7yr. Objects with higher AGN luminosity (and higher AGN contribution to Lir) tend to have higher terminal outflow velocities and shorter gas depletion timescales, which might indicate that the molecular outflows in these systems are mostly driven by the AGN. ALMA offers for the first time the possibility to extend these kind of studies to the high redshift Universe. We propose to observe the OH 119 micron doublet in two of the most luminous (Lbol ~ 10^14 Lsun) QSOs in the high redshift Universe: the Cloverleaf quasar (z=2.56) and ULAS J131911.29+095051.4 (z=6.13). We want to test if large scale molecular outflows at high-z are as effective as in the local Universe shutting down further star formation and black hole growth in the galaxy. The probable detection of OH P-Cygni line profiles in these high-z quasars will allow us to unambiguously identify the outflows and compare their properties (maximum outflow velocity, line EW) with the trends observed in the local Universe. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2015-05-02T12:38:00.000 |
| 1983 | 2023.1.00965.S | 0 | Establishing a link between the intracluster medium and star formation in galaxies with ALMA Band 1 | We aim to investigate the influence of the intracluster medium (ICM) on star formation in galaxies by obtaining a high-resolution detection of the ICM in MS0451, a well-studied galaxy cluster at z = 0.5. The ICM comprises a hot gas that interacts with galaxies through ram-pressure stripping, potentially leading to the cessation of star formation. Rich ancillary datasets of the target cluster exist: MUSE and HST provide accurate characterization of the star-forming properties of its member galaxies, and single-dish infra-red telescopes and X-ray telescopes have detected the ICM although at lower angular resolution. We will use the Sunyaev-Zeldovich effect to measure the ICM temperature, pressure, and electron number density at a better resolution than existing SZ detections. The proposed observations offers an opportunity to demonstrate the ability of the newly commissioned Band 1 in advancing ICM studies, and will help establish a direct link between the ICM and the star formation properties of galaxies within this well-studied clutser. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2025-05-06T09:27:26.000 |
| 1984 | 2015.1.00587.S | 175 | Why do isolated galaxies host red pseudobulges? | Despite the widespread idea that pseudobulges grow continuously via star formation, AMIGA sample of highly isolated galaxies is dominated by discs hosting red pseudobulges, consistent with an early formation epoch and scant subsequent growth. Only single dish studies of the molecular gas in isolated galaxies have been feasible so far, and those suggest it to be more extended than in denser environments, where gravitational torques/accretion from companions might play a dominant role in increasing SFE when compared to bars or gas accretion from the cosmic web. Although segregating the full range of environmental effects is crucial, most current studies mix galaxies residing in very different environments, and a reference sample where environmental effects are minimized is missing. We propose to map a sample of 18 very isolated galaxies in the CO(1-0) line with ALMA at 0.5" resolution in order to investigate differences in molecular gas distribution/kinematics between: disc/pseudobulges, barred/non barred, and compare with samples in denser environments. Solely ALMA can both map the disc of a significant sample of isolated galaxies and resolve their small pseudobulges in ~ 6h. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2017-07-14T19:12:58.000 |
| 1985 | 2019.1.01127.S | 7 | No Fire Without Fuel: Mapping atomic carbon around a massive quenched galaxy at z=1.91 | Recent observations with ALMA revealed a significant amount of cold gas remained (~10%) in quenched galaxies at redshift z>1.5, which is much higher than those found in typical local early-type galaxies (<<1%). The finding questions the primary driver of quenching mechanism at this redshift other than gas depletion. In this proposal, we aim to detect atomic gas in and around (r<40kpc) a massive (logM*=11.2), quenched galaxy at z=1.91. The galaxy was previously studied, revealing its compact morphology (with effective radius of 0.6kpc) and low metallicity composition. With such extraordinary nature, the galaxy is a uniquely powerful and ideal target to investigate the primary quenching mechanism. With an 8hr exposure with Band 5, we will detect atomic carbon (via [CI]1-0 line) down to 25uJy, or H2 gas mass of 5*10^Msun. Spatial and kinematical distribution of atomic gas will reveal the quenching mechanism of this galaxy. The inferred gas mass map will also provide a unique opportunity to test the minor merger scenario i.e. whether massive, compact galaxies at high redshift will evolve to local early-type galaxies via the accretion of satellite galaxies and gas clumps. | Early-type galaxies | Galaxy evolution | 2021-04-14T03:46:51.000 |
| 1986 | 2021.1.00138.S | 43 | Constraining Ionization in a Diverse Sample of Protoplanetary Disks | Ionization is influential in shaping both physical and chemical structure in protoplanetary disks. However, ionization is poorly constrained in observed disks, with strong constraints towards only two sources, TW Hya and IM Lup. In both disks, it was found that ionization from cosmic rays is suppressed by two orders of magnitude, implying that coupling of disk material to magnetic fields may be too weak to explain angular momentum transport in this system. We propose a survey of ionization-tracing molecular ions towards seven physically well-characterized disks that will complement existing observations in the ALMA archive to place constraints on ionization in a diverse disk sample. In addition to verifying whether or not low CR ionization levels are typical, the proposed observations will have implications for the cold ionization-driven chemistry occurring in these disks, which governs the formation of water and complex organics, and will additionally supply realistic, observationally motivated ionization models for future disk physical modeling, namely magneto-hydrodynamic (MHD) simulations. | Disks around low-mass stars | Disks and planet formation | 2023-06-15T21:24:17.000 |
| 1987 | 2023.1.01365.S | 0 | Observation of high excitation lines of NGC 7469 for a robust submm energy diagnostics of XDR vs PDR | A great way to uncover dust-obscured AGNs can be via molecular/atomic emission lines at (sub)mm (least affected by dust extinction) which are elusive at optical. In Izumi et al. 2020, the AGN (XDR) in NGC 7469 was found to have a [CI](1-0)/13CO(2-1) line ratio about 10 times higher than in starburst (PDR). This ratio is potentially a good marker of AGNs that could be used in a new diagnostic method for dusty environments. Therefore, it's important to quantitatively evaluate whether (1) very high gas excitation (temperature), (2) increase of C abundance from destruction of CO molecules, occurred by XDR. However, this isn't constrainable with archive data. So we need to observe high excitation lines ([CI](2-1), CO(7-6), and 13CO(4-3)) with 0.3" resolution in NGC 7469. This is the first, spatially resolved measurement of the high frequency lines of NGC7469. Here, we will (i) measure gas temperature and C/CO abundance ratio via non-LTE modelings (combined with archive data; [CI](1-0)), (ii) investigate spatial distribution & physical/chemical properties of gas, for XDR vs PDR characterization. Additionally, we will make a useful template for the interpretation of high-z objects. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-05-26T19:45:10.000 |
| 1988 | 2022.1.00194.S | 9 | Detailed Physical Properties of the Interstellar Medium in a z=5.2 Dusty Starburst (Completion) | Studies of the interstellar medium (ISM) at high redshift have progressed tremendously in the past years, but studies of the physical properties based on a suite of fine structure lines (which are critical for studying the earliest cosmic epochs, where CO is faint due to decreasing metallicity) are still in their beginning stages. We here propose to complete an in-depth study of the ISM based on six CNO fine structure lines in a massive starburst galaxy at redshift 5.2 (where all lines fall into a "sweet spot" in the atmosphere), allowing us to push these studies back to the first billion years of cosmic time. This will allow us to measure the fraction of [CII] emission that originated from the neutral vs. ionized medium, the density of both the neutral and ionized medium, the effective temperature in HII regions associated with star-forming clouds, and the O/N abundance ratio. This study will detect fine structure lines up to rest-frame wavelengths of 52 micron in one of the most distant starburst galaxies known, making it an ideal demonstration case for the ALMA band-10 receivers. | Starburst galaxies | Active galaxies | 2023-12-29T22:59:25.000 |
| 1989 | 2023.1.00336.S | 0 | Origins of Oxygen: ALMA probing chemical enrichment of the first stars | We propose band-6 observations to measure the [O III] 88 micron line in a galaxy unambiguously confirmed to be at redshift z ~ 11.6 by JWST/NIRSpec through identification of the Lyman-alpha break. This galaxy, JADES-GS-z11-0, is the most luminous spectroscopically confirmed galaxy at z > 10 in the Southern hemisphere. The NIRSpec measurements, however, are not able to capture any nebular emission. ALMA now has the unique opportunity to characterize the interstellar medium by directly probing the gas, metal, and dust content of a galaxy seen less than 400 million years after the Big Bang. A single deep line scan of dz ~ 0.2, using one full side-band in band 6, will cover >99% of the redshift uncertainty arising from the low spectral resolution (R ~ 100) NIRSpec observations confirming the break. Therefore, a detection yields the highest-redshift line confirmation to date as well as the earliest detection of oxygen. Even in case of a non-detection, the redshift constraints from NIRSpec guarantee that the ALMA observations will place meaningful constraints on the physical properties (i.e. metal and dust enrichment, gas density and ionization state) of this source. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2025-01-22T16:54:35.000 |
| 1990 | 2018.1.01112.S | 21 | Direct radiative feedback by the AGN on the cold molecular gas in NGC 2110 | We propose to observe multiple transitions of the HCN and HCO+ molecules in the nearby Seyfert 2 galaxy NGC 2110. Archival ALMA observations show a remarkable structure: a region of depressed CO 2-1 emission that is exactly filled by the extended (600 pc) AGN-ionised emission line region. A thorough study of existing data suggests that warm molecular gas found within the structure is being excited by the AGN. NGC 2110 may be the best example to-date of the direct and localised radiative impact of the AGN on cold molecular gas. With the proposed observations, we will be able to map the dense gas right around the nucleus, verify the role that the AGN plays in suppressing CO emission, and explore the excitation gradients in the circum-nuclear region. This will have important implications for our understanding of the regulatory role of AGN feedback in a normal and representative Seyfert AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2020-11-20T19:22:33.000 |
| 1991 | 2017.1.00614.S | 21 | Eccentric wide hot-subdwarf binaries: Testing the circumbinary disk hypothesis | Hot subdwarf B (sdB) stars are evolved core-helium-burning stars with exceptionally thin hydrogen envelopes. Wide sdB binaries are formed through stable Roche-lobe overflow (RLOF) on the tip of the red-giant-branch. Contrary to theoretical models which predict cirularization before the onset of mass loss, observations show that the majority of wide sdB binaries have significantly eccentric orbits. One of the main unknowns during the evolution of these post-RLOF systems is the formation of a circumbinary dusty disk during the mass-loss phase. The interaction of such a disk with the binary is the only mechanism that can explain the observed high eccentricities of wide sdB binaries. Although there is plenty of circumstantial evidence for the existence of such a disk, no direct detection has been attempted untill now. With this proposal we will attempt the first direct detection of a CB disk around wide sdB binaries. The results will be used to test the current binary interaction models requiring such a disk, while derived dust masses will be used to further refine these models. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2019-06-27T14:11:36.000 |
| 1992 | 2016.1.00931.S | 53 | An Anemone galaxy: Dense clouds and filaments at the leading edge of ram pressure stripped Coma spiral NGC 4921 | We propose to map CO(2-1) molecular gas along the leading edge ISM front of the strongly ram pressure stripped spiral NGC 4921 in the Coma cluster. This massive face-on spiral shows the clearest and most spectacular ram pressure leading edge dust front known, with numerous young star clusters and associated dense clouds decoupling from stripped disk gas. We seek CO(2-1) observations at 0.2'' resolution in a 20''x50'' mosaic along the leading side to learn the gas surface densities and kinematics to properly interpret the physical processes that occur in the dense gas during strong stripping. We will characterize numerous types of ISM features associated with ongoing rps, including the linear, V-shaped, and Y-shaped filaments extending from upstream heads, which are proposed to be in different evolutionary stages of decoupling. Mapping the gas surface densities near the leading edge will constrain molecular gas formation through gas compression. Comparison of simulations with these detailed observations will give us a better understanding of the efficiency of stripping, and therefore its impact as a quenching mechanism throughout the universe. | Galaxy groups and clusters | Cosmology | 2018-07-26T04:25:52.000 |
| 1993 | 2012.1.00799.S | 6 | Resolving the double gaps in the disk around HD 169142 | Gaps and holes of the transitional disks have been attracting attention, since such structure has been expected to be the result of the dynamical interaction between the forming planet and the disk, though grain growth and photoevaporation can also create such structures. Recently, Subaru/HiCIAO near-infrared observation revealed a possible double-gapped structure in the transitional disk around the Herbig Ae star HD 169142. Such structure is hard to be created by photoevaporation and/or grain growth alone, thus double-gapped structure can be a smoking-gun evidence that the forming planets are actually present in the disk. However, infrared observations can trace only the surface region of the disk, thus the Subaru/HiCIAO detected gap can be either a true radial gap or rather a shadow casted by the inner disk structure. To know what is occurring in the possible double-gapped disk of HD 169142, here we propose to make high angular resolution imaging of the dust and gas disk around HD 169142 with ALMA in Band 7. Both the inner and outer gaps should be clearly resolved for the first time with the high spatial resolution (0.165”) achieved with ALMA, hence we can discuss the distribution of dust and gas in the gaps simultaneously. When both the dust and gas are depleted in the gaps, it strongly indicates that the forming planets are responsible for such double-gapped structure. When only the dust is depleted and the gas component remains in the gaps, it implies that the grain growth is a likely cause of the double-gapped structure of dust disk. In any case, this observation will reveal the origin of the amazing double-gapped structure found in the disk around transitional object HD 169142, and it will contribute our understanding of the evolution of transitional disks and planet formation. | Disks around high-mass stars | Disks and planet formation | 2016-12-03T10:00:04.000 |
| 1994 | 2015.1.01537.S | 0 | The Outer Disk of V582 Mon (KH 15D) | V582 Mon, also known as KH 15D, is a binary T Tauri star with nearly equal mass components totaling 1.3 solar masses in a tight (P=48.37 days), eccentric (e=0.6) orbit. As a member of NGC 2264, it has an inferred age of ~2 Myr and distance of ~750 pc. Its importance derives from the fact that it is embedded in a circumbinary ring that stretches from about 1-4 AU, spanning the terrestrial planet formation zone. The ring reveals its presence by occulting a portion of the binary orbit. It is composed of micron to mm-sized grains and is inclined to the binary plane, which causes precession as a coherent unit on a time scale of ~1000 years. Occultations will cease by ~2030; there is some evidence that a luminous giant planet has formed. Such rings must be a common feature of proto-Tatooine (circumbinary) systems such as KH 15D or we would never have found such a perfectly positioned one. With ~1 hour of ALMA time we can obtain a high confidence confirmation that an outer disk is present, determine its spectral index to about 10%, constraining grain growth, and search for a CO disk which will constrain the total mass of the stellar system and inclination of the disk. | Disks around low-mass stars | Disks and planet formation | 2017-03-24T21:09:05.000 |
| 1995 | 2019.1.01446.S | 17 | Search for interstellar precursors of adenine | We propose a targeted search for 4 molecules with potential connections to biology towards the NGC6334(I) star forming regions. These biological precursors of the nucleobase adenine are NH2CN, C3NH, HNCNH and HCCN. At present time, only the 3 first species have been detected towards star forming region. Nonetheless, our APEX data strongly indicate the presence of HCCN towards NGC6334(I). Thus, a question remains open: can interstellar chemistry readily produce these molecules and in what abundance? This has particular importance when considering that the conditions seen in hot cores are replicated in protoplanetary disks at radii commensurate with the terrestrial planet forming zone. The aim of this proposal is to use the high sensitivity capability of ALMA to begin a sensitive census of biological precursor molecules in star-forming regions. Incidentally, these observations will allow us to confirm our HCCN detection in NGC6334(I). Finally, as we aim to couple laboratory experiments and theoretical chemistry with observations and modelling, the proposed observations will guide further development of chemical networks (for gas phase and grain surface reactions). | High-mass star formation | ISM and star formation | 2021-06-16T20:30:13.000 |
| 1996 | 2021.1.01081.S | 9 | LiH | Li abundances of Big Bang Nucleosynthesis prediction and meteorites are significantly higher than the ones measured in old metal-poor stars and in current Solar photosphere, respectively. These discrepancies are the long-standing cosmological lithium problem and lithium problem in the Sun, which plague our current understanding of cosmology, stellar evolution, and Galactic chemical evolution. Though the majority of the interstellar Li is in the form of LiH according to its chemistry, there is no evident LiH detection in previous observations, including several attempts with ALMA, indicating that LiH may be frozen on ice. Therefore, we propose to observe LiH 1-0 with ALMA towards Sgr A*, whose extremely turbulent environment might release LiH to the gas phase. The determination of the interstellar LiH abundance of Sgr A*, along with previous ALMA LiH observations toward other clouds with low turbulence, will allow us to i) figure out whether the interstellar LiH is in gas, or in ice, ii) constrain the molecular chemistry in shock conditions, iii) understand the Galactic Li evolution, and iv) shed light on the lithium problems. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-03-30T07:14:25.000 |
| 1997 | 2016.1.00852.S | 17 | Mapping CO(1-0) in a turbulent, clumpy disk at the Jeans length | Over 2/3 of the stars in our universe formed in galaxies at redshifts z = 1 3. During this epoch, star forming regions in typical, main-sequence, galaxies are 10 100× brighter than HII regions in local galaxies and are contained within extremely gas rich, turbulent disks. However, due to poor resolution there is limited information on the clumps themselves. A key missing parameter is the depletion time of gas at the resolution scale of individual star forming clumps. Even with HST or adaptive optics measurments of SFR is not sufficient on typical glaxies at z>0.5. In our program we circumvent the challenges of redshift by studying rare, nearby galaxies that are closely matched in properties to z=1-3 turbulent disk galaxies. We have in hand HST maps allowing measurement of SFR at ~100 pc resolution. We now propose to map CO(1-0) in 3 clumpy, gas rich disk galaxies at z=0.14 at similar resolution. Using DYNAMO we can not only make high-spatial resolution observations, but we also use well studied techniques of low-z Universe to study galaxies that are more common at z=1-3. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2018-12-19T20:08:03.000 |
| 1998 | 2015.1.00329.S | 59 | Do Optically-Luminous PG QSOs in the Local Universe Reside in Molecular Gas-Rich Hosts? | We propose to test the hypothesis that bright UV-excess PG QSOs reside in molecular gas-rich hosts by obtaining CO(1-0) observations of the 5 most luminous, distant PG QSO hosts which were undetected in our z < 0.3 IRAM 30m Telescope survey. Approximately 38% of the hosts were detected, but of the more distant, bright QSOs with high stellar mass hosts, only major mergers were detected. We focus here on QSOs with relatively undisturbed hosts; these hosts are ellipticals or late-stage mergers. Their far-IR excesses favor the latter interpretation, thus they may be the tail-end of the ULIRG-to-optical QSO evolution. These observations, combined with our IRAM data, will enable us to assess the star formation and ISM properties over the full range of host morphologies, and thus place these hosts in the context of ULIRGs and QSOs with prior CO detections. The primary goals of this study are (1) to determine if optically-luminous QSOs, as a class, reside in gas-rich hosts and (2) to assess whether the ISMs of these extreme QSOs are similar to that of local spiral and starburst galaxies by measuring their gas-to-dust ratios. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-01-14T00:24:40.000 |
| 1999 | 2013.1.01242.S | 0 | SiO Observations of the Circumnuclear Molecular Ring and Its Interior | Recent ALMA, CARMA, SMA, VLA and GBT observations of the Galactic center show highly excited SiO (5-4) and (2-1) line emission as well as methanol and water masers within 2' of Sgr A*. These emission lines are considered to be excellent indicators of on-going star formation activity. We aim to firmly establish that these lines are indeed tracers of on-going star formation between 0.2 and 6 pc from Sgr A* in the orbiting molecular ring and its interior. This will be achieved by resolving the SiO (5-4), (7-6) and (2-1) line emission from protostellar outflow candidates and demonstrating the kinematics and morphology of jet driven outflows. In addition, we will search for continuum sources at the center of protostellar outflow candidates to determine whether they have a dust spectrum. This ALMA study of the molecular ring and its interior will pin down the star formation hypothesis and will be able to distinguish between clump-clump collisions versus on-going star formation within the inner 6 pc of Sgr A*. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2016-12-22T00:02:21.000 |
| 2000 | 2018.1.00532.S | 71 | GG Tau ring: Dust trap or not Dust trap, that is the question... | We propose to observe the gas and dust ring orbiting the triple TTauri star GG Tauri. Located about 180 to 260 au from the star, this ring has a total mass of 0.13 Msun, estimated from 1.3 mm continuum measurements and a gas-to-dust ratio of 100. However, hydrodynamical models reveal that large dust particles can remain trapped at gas pressure maxima (dust traps), forming dust rings as those recently observed by ALMA around many transition disks. If the GG Tau ring is a dust trap, its total mass can be lower by a factor of 3-5. To check this, we propose to directly measure the gas mass by observing the ring in CS J=5-4 at the resolution of 0.3 arcsec because with its high dipole moment, CS is a high density tracer. We will analyse these new data with the existing images in CS J=3-2 (NOEMA) and CS J=7-6 (ALMA projects 2012.1.00129.S and 2015.1.00224.S at 0.4 and 0.1 arcsec). By performing non-LTE analysis, with these 3 transitions we will be able to determine the H2 density and temperature in the ring, and thus measure the gas mass and the gas-to-dust ratio. | Disks around low-mass stars | Disks and planet formation | 2019-12-31T16:05:23.000 |
| 2001 | 2012.1.00303.S | 3 | Inner disc, dust ring and spiral-like structures in the circumstellar disc AB Aurigae | More and more circumstellar discs around pre-main-sequence stars are found to have complex structures, such as great cavities seen in thermal dust emission and spiral-like features seen in the optical near-infrared images. Among them, AB Aurigae exhibits a spectacular spiral pattern. One popular formation mechanism often invoked for these two structures is the gravitational perturbation created by embedded companion/brown dwarf in the discs. However, the explanations of the spiral formations are purely based on the morphologies due to the lack of the kinematic information. We have started SMA+PdBI+30m observations toward AB Aurigae with high sensitivity and high angular resolution to trace the kinematics of the spirals using CO lines. Using the 12CO 2-1 images with 0.5" resolution of AB Aurigae, we found the "spiral" like features appear counter-rotating with respect to the circumstellar disc. Late accretion from the envelope above and below the disc plane is the simplest explanation for this. We propose to observe the spiral-like structures using 12CO 3-2 and 13CO 3-2 lines and the dense disc using 0.88 mm continuum with the highest angular resolution of 0.2". This will allow us to constrain the density and kinetic temperature of these spiral-like structures, to resolve/detect the possible inner disc, the streamer and the dust ring, and to determine to what extent this infalling material affects the ring properties. | Disks around high-mass stars | Disks and planet formation | 2016-10-31T23:32:19.000 |
| 2002 | 2017.1.00706.S | 103 | Through the magnifying glass: ALMA's sharp view of the core of OH231.8+4.2 | OH231.8 is a key object to understand the remarkable changes in nebular morphology and kinematics during the short AGB-to-PN transition. We have recently mapped with ALMA the fast bipolar outflow around this extreme AGB star unveiling an extravagant array of structures that urge us to reconsider the nebular formation scenarios proposed to date. We aim at a follow-up study with higher angular resolution of the most enlightening structures discovered, which lie at the core but are only marginally resolved in our 0.2"-resolution maps. For the first time, ALMA brings to light the position of the mass-lossing star QX Pup, which we found to be enshrouded inside a thick gas/dust <0.15" clump. The star is launching a <100yr old bipolar outflow selectivelty traced by SiO(7-6). We propose to map the continuum and line emission from the core in band 6 with ~0.02" resolution. We will observe SiO v=0 J=6-5 and J=5-4 to isolate the young bipolar outflow and a series of high-excitation transitions to probe the inner layers of the AGB envelope. The proposed observations will bring us to the closest we have ever been to live-watching the launch of a bipolar outflow from a mass-lossing star. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2019-12-05T17:30:28.000 |
| 2003 | 2018.1.00064.S | 34 | Wind and Turbulence: Tracing [CI] in the Resolved Galactic-Scale Outflow in Circinus Galaxy | Galactic winds regulate feedback, quench star formation, and are thought to limit the total mass in galaxies. ALMA has revolutionized our understanding of the molecular phase of nearby winds via the brightest tracer: CO. However, CO is easily dissociated into [CI] when exposed to energetic radiation in powerful starburst- or AGN-driven winds. Thus, much of the molecular mass is missed by CO. Consequently, the molecular mass outflow rates and energetics of the winds -- crucial parameters for understanding the driving mechanisms and impact of galactic-scale winds on the evolution of their host galaxies -- are underestimated. Fortunately, [CI] is sufficiently bright compared to CO to make effective line ratio assessments, and is a complementary tracer of H2. [CI] also suffers less from high optical depth effects. Thus, observations of [CI] can recover the missing molecular mass. We propose to map [CI] in the Circinus Galaxy, the nearest Seyfert, which hosts a well-known AGN-driven wind. Low resolution observations indicate that the wind in Circinus has a relatively large fraction of dissociated CO in the form of [CI], making it ideal for resolved [CI] observations. | Outflows, jets, feedback | Active galaxies | 2019-12-07T20:55:09.000 |
| 2004 | 2015.1.01105.S | 48 | Tracing the reionization epoch with ALMA | Recent exiting results have shown that up to z=6 (just a billion years after the Big Bang) star forming galaxies have [CII] emission comparable to the low redshift metal poor galaxies; however at earlier epochs (z=7) the sceario is much more confused, with some indications that the [CII] emission from star forming galaxies is considerably below the epectation for a given SFR. Understanding how the properties of primeval galaxies evolve at these early epochs is crucial, since they are probably the key players in the process of reionization We propose to use ALMA to detect and map [CII]158 micron line in a representative sample of bright galaxies in the reionization epoch, for which we have obtained accurate redshifts from the Lyalpha emission line. These galaxies are the brightest is a new sample of high redshift galaxies that we observed with FORS2 as part of an ongoing ESO Large program. Our observations will be deep enough to either detect unambigously the [CII] line, or to set deep lower limits such that we will be able to conclude with no doubts that the properties of galaxies have evolved considerably in the time between z=7 and z=6. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2017-02-17T19:54:09.000 |
| 2005 | 2011.0.00101.S | 0 | Shedding Light on Distant Starburst Galaxies Hosting Gamma-ray Bursts v9 | Studies of distant starburst galaxies hosting gamma-ray bursts (GRBs) offer unique insights into extreme star-forming regions during early epochs. We propose to carry out a pilot program to observe the 345 GHz continuum from the host galaxies of GRB021004 and GRB080607 at z > 2 with ALMA. The selected targets show contrast examples in the host galaxy population in the observed neutral gas surface mass density in front of the GRB birth site. The host galaxy of GRB080607 exhibits a large gas surface mass density of ~ 400 M_sun pc^-2, including a large molecular gas column density in the afterglow spectrum. In contrast, the host galaxy of GRB021004 exhibits ionized ISM and complex velocity field in the afterglow spectrum. Both hosts have been identified with associated stellar light in late-time HST images and have constraints for the ISM metallicity from afterglow absorption-line measurements. In addition, the early-time afterglow spectra of the GRBs have revealed the presence of strong Mg II absorbers at z ~ 1.5. We aim to obtain a deep sub-mm map of the fields around the two GRB host galaxies with a 5-simga limit of 0.5 mJy in the 345 GHz waveband. This sensitivity limit is an order of magnitude improvement from previous single-dish observations of these fields that yielded null results. We expect that the proposed observations will allow us to resolve the extragalactic background light in the sub-mm and to constrain the dust luminosity of these luminous GRB host galaxies. The proposed pilot program will offer important insights into both the progenitor environment and the contribution of dusty starburst galaxies to the GRB host population at z > 2. It will also allow us to examine the dust luminosity of strong Mg II absorbers in the foreground. | Starburst galaxies, Gamma Ray Bursts (GRB) | Active galaxies | 2012-12-06T04:27:58.000 |
| 2006 | 2017.1.00707.S | 74 | Unveiling the nature of the very-low luminosity source in the Planck cold clump G204NE | Our high resolution (0.26" x 0.16") ALMA Cycle-4 observations have successfully detected very compact (60-120 AU in radius) CO evaporation areas around the first core candidate sources B1-bN and B1-bS. Our results imply that the CO evaporation radius can be a good indicator for the evolutionary stage of extreme young objects prior to Class 0. Here, we propose to examine nature of the very-low luminosity (0.027 L_sun) object in the Planck cold clump G204.4-11.3 NE.(G204 NE) Since this core has enough mass (3.2 M_sun) to form a low-mass protostar, we hypothesize that the source has a very-low luminosity because it is in the very early evolutionary stage. In order to test this hypothesis, we plan to observe the C18O, CO, N2D+, and H2CO lines in Band 6 at an angular resolution of 0.13" (= 55 AU at 420 pc). For a comparison, another Class0/I source, G204SW, in the same clump is also observed. The C18O and N2D+ lines will be used to determine the CO evaporation radius. The CO and H2CO lines will be used to study the properties of the outflow. The observed chemical and physical properties of the source in G204 NE will be compared with those of the FHSC candidate soures, B1-bN and B1-bS. | Low-mass star formation | ISM and star formation | 2019-01-11T23:37:07.000 |
| 2007 | 2011.0.00474.S | 0 | Where do massive stars get their mass from ? | Massive stars are most likely forming at the centre of parsec scale converging accreting filaments. MHD simulations predict that the gas along these filaments can show velocity differences of few km/s according to the direction of these filaments with respect to the cloud. SDC335.579-0.292 is a unique massive-star-forming Infrared Dark Cloud (IRDC). It shows pristine dark filamentary structures converging towards two of the most luminous protostars known in the Galaxy. Low resolution (36’’) molecular line studies of SDC335.579-0.292 suggest that this cloud is globally collapsing and that the dark filaments might be accreting in a similar way as in the simulations. However only high resolution (5’’) observations of the velocity field can confirm such speculations. We therefore propose to observe SDC335.579-0.292 with ALMA ES at 3mm in the compact configuration in order to get the systemic gas velocity along the set of filaments which are observed in this IRDC. We expect to measure velocity differences of a couple of km/s between the different filaments. This would strongly support the dynamical picture of massive star formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2014-03-01T00:00:00.000 |
| 2008 | 2018.1.00388.S | 149 | Detection of the First circumprimary/circumsecondary disks in Class 0 protobinary system: VLA1623A | Our proposal aims to detect and kinetically resolve the cirumprimary disks around Class 0 binary. It will be the first detection of circumprimary disks in Class 0 binary. Furthermore, we propose to use SO to trace shock fronts between circumbinary disk and accretion flows. The motion of circumprimary disk around the youngest Class 0 binary system will be observed and analyzed.This project will be an important observational test for binary formation theories. The goal of the proposal is to: (1) Detect the extremely young eccentric Class 0 circumprimary disks on VLA1623A binaries. (2) Detect shocks on the outer circumbinary disk and identify shock fronts. (3) Determine the temperature of the circumbinary disk around VLA1623A binaries. | Low-mass star formation | ISM and star formation | 2020-08-17T20:28:20.000 |
| 2009 | 2011.0.00647.S | 0 | The origin of molecular jets: new clues from CO and SiO in HH212 | We propose to use ALMA in its extended configuration to investigate the SiO bipolar microjet driven by the low-mass protostar HH212. We wish to constrain its origin by observing CO(6-5) at 691.5 GHz at the unprecedented angular resolution of 90 AU. We propose to observe also CO(3-2) and SiO(8-7), on a 220 AU scale, with a sensitivity at least one order of magnitude higher than that of previous SMA data. In this way, we will be able to constrain for the first time the CO opacity, the SiO abundance, the jet density and mass-flux rate on a 220 AU scale. These parameters will hold crucial clues to the jet launch region. Observations will be confronted with updated predictions for SiO in C-shocks and dust-free wind models, to elucidate the SiO formation process. | Outflows, jets and ionized winds, Astrochemistry | ISM and star formation | 2014-02-26T08:04:00.000 |
| 2010 | 2013.1.00463.S | 0 | Mass growth at high-z: molecular gas and dust in the core of a galaxy cluster at z=1.63 | Over most of the cosmic history, rich galaxy environments such as galaxy clusters are places of little ongoing star formation. This trend is expected to reverse at high redshifts, however, when clusters and their constituent massive galaxies are forming, likely via interactions and mergers between massive, gas rich galaxies. A z=1.63 galaxy cluster from the SpARCs survey forms such an environment, for which we have 18 spectroscopically confirmed cluster members. One of these galaxies, in the core of this cluster, appears to be associated with a bright 250 micron source (most likely a blend of several fainter sources) detected by SPIRE on Herschel. It is also relatively close to the BCG, which is bright at 24 micron. We aim to resolve the confused SPIRE source in ALMA band 7 using seven pointings on and around the galaxy associated with it, and four adjoining pointings on the area towards and including the BCG. This will establish the origin of the 250 micron flux. In addition, we aim to measure the CO(2-1), CO(3-2) and CO(5-4) line fluxes (and possibly linewidths) to estimate the molecular gas mass and temperature of the SPIRE source(s), using ALMA band 3, 4 and 6 respectively. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2017-02-05T11:57:04.000 |
| 2011 | 2017.1.01158.S | 1006 | ACA Study on the Driving Mechanisms of Starburst and Main-Sequence Star Formation in Local Galaxies | We propose an ACA stand-alone observation in 12CO (J=2-1) emission line of 56 local galaxies to reveal the driving mechanism of different star formation modes in galaxies, starburst and main-sequence star formation. The two modes are described on the stellar mass - star formation rate plane. The previous studies have found that starburst galaxies often involved with galaxy mergeres and have more compact star-forming regions than main-sequence galaxies. These results imply that galaxy mergers drive compressed gas and resultant high activities of star formation. However, this picture is observationally unclear because the information on the extent of molecular gas distribution in galaxies is poor. Therefore, we systematically measure the CO extent of the galaxies with the ACA's resolutions (6"). Our sample widely ranges from main-sequence galaxis to starbursts, and is composed of 35 disk galaxies and 21 mergers. This observation enable us to directly compare between star formation levels, morphologies, and extents of molecular gas distribution. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2019-02-15T12:58:38.000 |
| 2012 | 2019.2.00030.S | 59 | Revealing Chemical Diversity and Chemical Evolution in the NGC2264-D Cluster-Forming Clump | It is essential for understanding formation processes of massive stars and the solar system to reveal the formation and evolution of cluster-forming regions. Chemical composition is known as a useful tool to investigate the evolution and physical conditions of starless and star-forming cores. We apply similar methods using chemical composition to the larger cluster scale. We propose observations of carbon-chain species (HC3N and HC5N), CH3OH, and CH3CN in Band 3 toward two clumps in NGC2264-D, n3 and n5, with the ALMA ACA. The NGC2264 cluster-forming region is an ideal target source to study clusters with high-mass protostars because it is the second nearest cluster. We will derive the (carbon-chain species)/(complex organic molecules) ratios to investigate the chemical evolution and chemical diversity along filament and those of each clump and test our hypotheses regarding the cluster formation. Such chemical studies have never been tested in cluster regions so far, and thus, our proposed observations will be unique. | Astrochemistry | ISM and star formation | 2021-05-06T17:21:57.000 |
| 2013 | 2022.1.00112.S | 11 | Young Massive Star Clusters in the Local Galaxy Merger NGC 3256 | According to hierachical collapse models, most young stars in starburst systems are formed in young massive clusters (YMCs). Therefore, it is important to study the properties of these YMCs to understand the star formation process in these systems. We propose to observe the nearest lumninous infrared galaxy, NGC 3256, with Band 3 and Band 7 continuum at ~0.05" (~10 pc) resolution to measure the stellar mass and gas mass of embedded YMCs. We also request simultaneous CO 1-0 and 3-2 line observations to help better constrain the gas mass in these YMCs.. From these observations, we will achieve a better undertanding of the YMC propperties and their interaction with GMCs. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2024-10-10T11:53:05.000 |
| 2014 | 2019.1.00579.S | 29 | Unlocking large-scale vortices in protoplanetary discs | One serious challenge for planet formation is the rapid inward drift of pebble-sized particles in protoplanetary discs. Dust trapping at local pressure maxima is proposed to stall this drift allowing the formation of planetesimals. The cold dust emission in AB Aurigae forms an asymmetric ring suggestive of dust trapping. Our continuum images at 2mm and 1mm (0.78"x0.58") show that the intensity variations along the ring are smaller at 2mm than at 1mm, contrary to what dust trapping models predict. Two-fluid simulations prove that this feature can only arise if the gas vortex has started to decay due to turbulent viscosity, and dust particles are thus losing the azimuthal trapping. Yet, our interpretation is limited by the angular resolution and wavelength coverage of our data. We propose to image the AB Aurigae disc in the continuum at 2mm and 1.3mm, at an angular resolution of 0.07"-0.15" to radially and azimuthally characterize the dust trap. Assuming that the dust trap is caused by a giant planet, our simulation indicate a possible detection of dust emission at the Lagrangian point 60 degrees behind the planet. This detection would challenge current planet formation theories. | Disks around low-mass stars | Disks and planet formation | 2022-07-28T11:16:18.000 |
| 2015 | 2022.1.01507.S | 2727 | A CO emission follow-up survey of the DINGO Pilot survey: the evolution of molecular gas over the past 3 Gyrs | The differing evolutions of the cosmic densities of gas and star formation post the cosmic noon (z<2) is a subject of intense ongoing research. Recent comparative measurements of the cosmic densities of SFR, stars, atomic hydrogen (HI) and molecular hydrogen (H_2) suggest that it is necessary over the past Gyrs for (i) the HI reservoirs of galaxies to replenish through infall, and (ii) HI to convert to H_2 at the centres of galaxies, in a fine balancing act as the molecular gas depletion timescale does not change with redshift, while HI density is higher than H_2 density at all redshifts. To disentangle this process we need to measure the H_2-to-HI content in the same set of galaxies in bins of stellar mass, SFR, and environment, and at different redshifts. DINGO is an ongoing survey of HI upto z=0.4 in the GAMA survey regions, which is making it possible for the first time to undertake such a study. We propose a pilot survey to observe the CO(1-0) line emission using standalone ACA from galaxies within the central 1 deg. x 1 deg. area observed in the DINGO pilot survey, in two redshift ranges covering upto z=0.26 (past 3 Gyrs), and use stacking to reach our science objectives. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2024-07-26T00:55:42.000 |
| 2016 | 2022.1.01071.S | 37 | Scrutinizing the dust-formation region in AGB stars with ALMA and SPHERE | We will study the mass-loss process experienced by low- and intermediate-mass stars at the end of their lives using quasi-simultaneous ALMA and SPHERE observations of a small sample of AGB stars. These data will spatially resolve the crucial dust-formation region at visible and sub-mm wavelengths, providing crucial constraints for our understanding. While the SPHERE images of polarised light will reveal the distribution of the dust grains that drive the outflow, the ALMA observations will probe the gas properties that allow dust to nucleate and growth. Our strategy builds on previous observations of this type to better constrain the gas density and temperature distributions. Specifically, we aim to obtain an accurate picture of the gas temperature in the innermost regions because recent results reveal a steeper temperature profile than expected. The degree of variation of the gas density and temperature as a function of position, and the correlation between these two quantities will be directly compared to state-of-the-art 3D hydrodynamical codes. In this way, we will test the assumptions and validity of predictions from such theoretical models in an unprecedented way. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-10-06T11:58:06.000 |
| 2017 | 2015.1.00152.S | 20 | Tracing the massive galaxy evolution in z = 2.5 protocluster with dense molecular tracer and atomic line | We propose emission line surveyes for CO(4-3) and [CI] to investigate the evolutionary track of massive galaxies and possible environmental effects. Our samples are H_alpha emitters (HAEs) associated to the protocluster at z = 2.5, which are identified with Subaru narrowband survey. The multi-band data sets of radio, submm in hand have revealed interesting results that suggest variety of evolutionary phases among HAEs and presumably, the on-set of environmental effect. Our primary goal of this proposal is to confirm and study the truth, via CO(4-3) and [CI] observation. In detail, we would like to investigate items as follows: (1) Study the total gas content with various indicator : CO(4-3) and [CI] (2) Model the kinematics to investigate the velocity strucutre and the physical mechanism (3) Test the KS law of sub-mJy sources in kpc scales (4) Derive global gas properties from CO ladder, [CI] and dust continuum (5) Constrain the dust temperature of sub-mJy SMGs | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2018-04-14T10:41:45.000 |
| 2018 | 2019.1.00187.S | 84 | Initial mass estimates for AGB stars from oxygen isotopes | Asymptotic giant branch (AGB) stars are significant contributors of enriched gas and dust to the interstellar medium (ISM). The initial masses of individual AGB stars have only been estimated for a few stars. This value is important for understanding the full evolutionary processes of low- and intermediate-mass stars before, during and after they enter the AGB phase, including how much enriched matter they return to the ISM. The abundance ratios of the rarer oxygen isotopes can be used, in conjunction with stellar evolution models, to estimate the initial masses of AGB stars. With this proposal, we wish to observe C17O and C18O with the goal of determining the initial masses for our sample of AGB stars, all of which have been previously observed at high resolution. With the requested observations we will be able to check the initial mass dependence of the morphological and chemical properties of our sample stars. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2021-01-27T16:14:57.000 |
| 2019 | 2016.1.00470.S | 15 | The puzzling eclipse of J1407 - a giant exoring system? | In 2007, the 16 Myr old pre-main sequence star, 1SWASP J1407, underwent a complex eclipse up to three magnitudes deep (>95%) and lasting about 50 days. The best explanation to date is that the star was eclipsed by a substellar companion with a gigantic ring system with gaps carved by moons. This would be a spectacular first discovery of an extrasolar planetary ring system, but more data is required to make progress on the interpretation. Extensive follow-up, including continuous monitoring, with telescopes at optical wavelengths has yielded no further detections yet. Due to its sensitivity to cold dust emission, and its high angular resolution, ALMA is the best instrument to constrain the nature of the eclipsing object. These observations could yield the first confirmed detection and mass measurement of an exoplanetary ring system. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2018-08-02T12:21:21.000 |
| 2020 | 2016.1.01182.S | 57 | (Proto)Binaries and multiplicity properties in high-mass star-forming clusters | In this proposal we ask for ALMA band-6 observations to study the multiplicity properties in massive star forming clusters in different evolutionary stages with the goal of investigating how multiplicity varies with the cluster evolution. We plan observations with an angular resolution of 60 mas of four young, massive star-forming clusters at different stages of embeddedness. We wish to: (i) search for (proto)binary/multiple systems candidates, (ii) determine their properties (e.g. separation, mass ratio) and (iii) compare their spatial distribution to large-scale properties of the clump in which they are embedded (e.g. radial profile, turbulence level from relative velocities of the members of the cluster). These observations will be compared to predictions by numerical simulations and, eventually, be complemented by VLT infrared high-angular resolution observations. ALMA is well suited to target young, embedded clusters, while already proposed VLT infrared observations will focus on the study of more evolved objects in open clusters. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2019-09-27T00:00:00.000 |
| 2021 | 2015.1.00449.S | 57 | Fragmentation of massive dense clumps: unveiling the initial conditions of high-mass star formation | This is the resubmission of project 2012.1.00366.S, approved in cycle-1, postponed to cycle-2, but not observed yet. The project aims at determining the population of dense cores (size, number, spatial distribution) embedded in 11 carefully selected massive clumps through high-angular resolution observations of N2H+ (3-2) and (sub-)mm continuum, in order to test high-mass star formation competing theories. High-mass stars are born from the gravitational collapse of such clumps (i) either via competitive accretion in highly fragmented clumps (ii) or through accretion onto single cores if fragmentation is suppressed. Simulations show that the fragmentation process is efficiently inhibited if a strong magnetic support dominates the dynamics during collapse. Vice-versa, a faint magnetic support favours the formation of many small fragments. Therefore, if the magnetic support dominates over turbulence in the formation of massive stars, we expect a majority of clumps with low fragmentation levels, and vice-versa. | High-mass star formation | ISM and star formation | 2017-10-21T11:48:24.000 |
| 2022 | 2013.1.01258.S | 15 | Tomography of a Galaxy Protocluster at z=5.3 | Cosmological simulations suggest that massive galaxies at present day formed in the densest regions in the early universe, predicting the existence of massive protoclusters of intensely star-forming galaxies at high redshift. We have recently identified such a unique region within 1.1 billion years of the Big Bang, hosting an extreme starburst and at least 13 normal star-forming (Ly-break) galaxies, within a narrow redshift interval (dz=0.002). This environment is a "smoking gun" for early massive galaxy formation through hierarchical buildup, giving key importance to understanding the physical properties of its member galaxies in detail. Building on our efforts in cycle-0, this proposal aims to add an essential missing piece to our comprehensive dataset on this region by mapping it out in [CII] and far-infrared continuum emission, and by imaging the cycle-0 targets down to 850 pc resolution. This will critically constrain the interstellar medium content, excitation, distribution and gas dynamics of the protocluster members, constituting their fuel for star formation, and dust-obscured star formation rates. This will be the first detailed ISM study of Ly-break galaxies at z>3. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-06-05T14:29:59.000 |
| 2023 | 2017.1.00066.S | 18 | Distance and nature of a dust cloud towards NGC 3269 | A small patch of dust with a diameter of 4" is seen projected against the Sa-galaxy NGC 3269. Its distance is unknown, i.e. the cloud may be associated with the galaxy itself or it may be a small cloudlet in the local ISM, or a larger dust cloud in the Milky Way halo. If in NGC 3269, it would be a rare case of an isolated GMC complex in an Sa galaxy otherwise devoid of any traces of ISM or ongoing star formation. If within the Galactic dust layer at d 100 - 500 pc, it would represent a (sub)Jupiter mass cloud with a diameter of 2-10 10^-3 pc or 400-2000 A.U. If in the halo at d 10 kpc its size would be 0.2 pc, corresponding to a large globule. Another intriguing possibility is that the dust patch is related to the nearest supernova remnant only 10' away that was discovered recently. The distance then could be about 140 pc. In order to decide between these different alternatives and to derive some basic physical properties of the object we propose to observe it in the 230.538 GHz 12 CO(2-1) spectral line with ALMA. We wish to emphasize that whichever the distance of the dust patch turns out to be the cloud will be a unique first example of its class. | Low-mass star formation | ISM and star formation | 2019-08-31T21:43:33.000 |
| 2024 | 2018.1.01631.S | 81 | Probing the Sulfur Chemistry in Protoplanetary Disks | Circumstellar disks are the birthplace of planets. These protoplanetary disks (PPDs) constitute a pivotal stage in the evolution from interstellar molecular clouds to planetary systems. Their chemical structures encode information both on the chemical evolution during star and planet formation, and on the future compositions of forming planets. With this proposal we address the elusive sulphur chemistry in disks. In Cycle 3 and 4, we observed CS 5-4 in five PPDs in the Taurus region and, for the first time, detected H2CS and CS isotopologues in disks (only targeted toward 2/5 disks). We propose to use B6 and B7 lines of these molecules to map out the sulphur chemistry and volatile reservoir in three disks, maximally leveraging the previous detections. The complete data set will contain several lines for each species, which will allow us to both measure their abundances and constrain their radial and vertical distributions. Our proposed set-ups will also cover strong lines from S-bearing molecules that have been detected in PDRs, protostellar envelopes and prestellar cores, and whose detections would provide additional constraints on the PPD sulphur disk chemistry. | Disks around low-mass stars | Disks and planet formation | 2021-01-30T21:03:33.000 |
| 2025 | 2023.1.00454.S | 0 | Probing host galaxy dynamical mass of the most luminous quasars at cosmic noon | To address the fundamental, yet unsolved, issue of supermassive black hole (BH) growth and its link to galaxy evolution, it is crucial to measure accurately the mass of both the central BH and of the host galaxy. The combination of the on-going upgrade of the VLTI/GRAVITY near-IR interferometer, GRAVITY+, and the capabilities of ALMA provide a unique opportunity to make decisive progress. While GRAVITY+ will enable accurate measurements of BH masses from the size of the broad-line region out to beyond the cosmic noon epoch, ALMA can measure the dynamical mass of the host via submillimeter molecular gas line kinematics -- the only viable method for the most luminous distant quasars. Moreover, while host masses have been well determined for sizable samples of local and z>~6 quasars, few have been obtained at z~2. We propose to observe CO(3-2) line emission with ALMA to weigh the host galaxies of a unique sample of southern luminous quasars at z~2.3 for which GRAVITY+ will obtain accurate BH mass, and to bridge the existing censuses of host masses at low- and very high-redshift. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-03-16T15:52:58.000 |
| 2026 | 2015.1.01148.S | 30 | Molecular gas in WISE-selected Hyper-luminous Hot, Dust-obscured Galaxies | A new population of hyper-luminous, dusty obscured galaxies at z~ 2-3 using WISE has been discovered recently. They are hyper-luminous and rare (about 1000 such objects in all sky). They also trace the peak epoch of cosmic star formation and QSO activity. The hot dust temperature and extremely high luminosity indicate that these objects are likely heavily obscured quasars. The detailed SED decomposition found that the emission from cold dust contributes a small part of the total IR luminosity but is still comparable to those found in SMGs, indicating SFRs ~1000 solar mass per year. The physical conditions of molecular gas will be crucial to understand how both starburst and QSO activities have been fueled. The previous attempt to detect CO line failed due to shallow line sensitivity. Here we propose to detect CO J=4-3 line of three such objects with ALMA band 3 in order to 1) check L'CO- LIR relation; 2) study the total molecular gas content and galaxy kinematics; 3) search the molecular gas outflow which may be related to extreme starburst and QSOs activity. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-10-01T03:42:53.000 |
| 2027 | 2023.1.01276.S | 0 | Understanding disk substructures: relating the inner and outer parts of protoplanetary disks | We propose to observe 33 protoplanetary disks around nearby (<200 pc) young stars that have been fully characterized with high-resolution spectroscopy, from the ultraviolet to the infrared, as part of the HST/ULLYSES and VLT/PENELLOPE large programs. Our primary goal is to detect disk structures in the ALMA continuum in order to unveil their origin by comparing their morphology with the properties of the inner disk (mass accretion rates, winds/outflows) estimated from their spectra, critically testing different disk evolution models. The addition of ALMA to this multi-wavelength, multi-technique observational effort will provide a holistic view of the inner and outer disk in order to obtain, for the first time, observational evidence that links dust structures to inner disk properties for a significantly large well-characterized sample of young stars in different star-forming regions. This comprehensive dataset can then be used as a benchmark sample in population studies. The data obtained from this proposal will be immediable available to the community. | Disks around low-mass stars | Disks and planet formation | 2025-04-09T13:21:05.000 |
| 2028 | 2021.1.00306.S | 85 | Testing the SFE bimodality: measuring the CO-to-H2 conversion factor in ULIRGs using 13CO | Local ultraluminous infrared galaxies (ULIRGs) are gas and dust-rich major mergers hosting strong starbursts. They have star-formation efficiencies (SFE) much higher than main-sequence galaxies and indeed the existence of a SFE bimodality has been suggested based on these differences. The SFE of ULIRGs relies on the CO-to-H2 conversion factor (alpha_CO) assumed for ULIRGs, ~4 times lower than the standard Galactic alpha_CO. Warmer, denser, and more turbulent ISM in ULIRGs could justify a reduced CO optical depth and, hence, a reduced alpha_CO. However, the nuclear gas column densities in ULIRGs are very high and recent spatially resolved ALMA data suggest highly suppressed 12CO emission in, at least, some ULIRGs, which would be at odds with a reduced alpha_CO. We propose to observe the optically thinner 13CO isotopologue in a representative sample, in terms of interaction stage and nuclear 12CO emission suppression (from flat-top to Gaussian-like line profiles), of ULIRGs (10 new + 2 archive). We will determine the nuclear optical depths using radiative transfer models and estimate their alpha_CO, which is key to establish their SFE and the existence (or not) of a bimodal SFE. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2023-06-23T13:31:30.000 |
| 2029 | 2024.1.00382.S | 0 | Star formation at extreme gas densities | Investigating the fragmentation process of molecular clouds at ultra high densities (n>10^7 cm-3) is essential to understand extraordinary star formation conditions such as those leading to the origin of globular clusters in the early Universe. We propose to investigate the OMC-1S proto-cluster as local analogue of the extreme gas densities expected at high redshift. We will obtain a new ALMA 12m+7m Band 9 mosaic at 652 GHz to resolve the N2H+ (7-6) emission previously detected by single-dish observations as unambiguous tracer of large reservoirs of gas at densities >10^7 cm-3. Mimicking the conditions in starburst galaxies, we aim to characterize the substructure and kinematics of this high density, star-forming gas in OMC-1S down to 200~au resolution. With these observations we will investigate whether the filament-to-core fragmentation mechanism observed in nearby clouds can be extrapolated into these extreme environments. These extreme star-formation conditions are expected to be common in the early Universe as recently revealed by JWST, but the underlying astrophysical processes can only be resolved with the proposed Band 9 observations. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 2030 | 2015.1.00024.S | 4 | Resolving the Rotation of Protostellar Jets | Protostellar jets are believed to be launched from accretion disks around protostars, carrying away extra angular momenta from the disks, allowing material to fall onto the protostars. Their launching radius and thus model (X-wind v.s. disk-wind) are still uncertain but can be determined from their rotation, which can be measured with ALMA's unprecedented sensitivity and resolution. HH 212 and HH 211 are two nearby well-defined jets lying almost in the plane of the sky, ideal for jet rotation measurement. We have mapped them at ~ 0.3" resolution, the highest achievable with the Submillimeter Array (SMA), with tentative detections of jet rotation. Since the jets can not be resolved by the SMA, we propose to observe them with ALMA at ~ 0.05" resolution, about 6 times higher than that in our SMA observations, in order to fully resolve the jets and measure their rotation precisely. At this high resolution, we can measure a rotation with a specific angular momentum down to a few AU km/s. No detection of jet rotation would cast serious doubt on the X-wind model and disk-wind model as the jet launching models. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-03-25T01:38:01.000 |
| 2031 | 2013.1.00659.S | 2 | Detecting in CO(1-0) the Strongest Molecular Outflow found by Herschel in the Southern Sky | We have recently discovered, in IRAS 20100-4156, the second most powerful molecular outflows seen in any ULIRG in the Local Universe. Judging from the absorption profile of the 119um OH doublet, its outflow properties are more extreme than those of Mrk231, itself the most extreme source in the Herschel-SHINING sample. Because of their exceptional molecular outflow properties we are obtaining further observations of these two sources to study their molecular outflows in detail. In March we obtained Herschel spectra of transitions between the excited levels of OH to constrain the outflow geometry. In August we obtained CO(1-0) data for the northern hemisphere target IRAS 03158+4227 from PdBI. Here we propose to observe the high-velocity wings of the CO(1-0) line in our southern hemisphere target IRAS 20100-4156 using the exquisite sensitivity and resolution of ALMA to measure the mass of the molecular gas in the wind, the geometry of the outflow to determine the outflow rate and kinetic power and, in combination with the measurement of the molecular gas reservoir from the CO(1-0) core, the gas depletion time scale for this still deeply buried, but possibly quickly evolving, ULIRG. | Merging and interacting galaxies, Outflows, jets, feedback | Galaxy evolution | 2015-09-27T11:05:12.000 |
| 2032 | 2021.1.01092.S | 20 | Uncovering the Molecular Gas Content of FRB Host Galaxies | Over the past 2 years, the fast radio burst (FRB) community has precisely localized ~10 events to their host galaxies. This affords a terrific opportunity to constrain the unknown origin(s) of these enigmatic signals through analysis of their stellar populations and high-resolution studies of their local environments. Optical and near-IR observations have now assessed the stellar components, including estimates of star formation rates and stellar masses. These reveal a diverse population of primarily star-forming galaxies favoring progenitor scenarios linked to more massive stars. Here, we propose to use ALMA to provide direct measurements of the cold gas present in FRB hosts via the CO J=3-2 emission-line. We will target six new hosts accessible with ALMA to survey their molecular gas masses and infer their star formation efficiencies. These results will be compared to the locus of normal, star-forming galaxies at low-z and the hosts of other transient populations (e.g. supernovae) to derive unique constraints on FRB progenitors. Last, these data will enable future programs to map CO at much higher spatial resolution and thereby dissect the very local environments of FRBs. | Surveys of galaxies | Galaxy evolution | 2023-04-20T21:47:07.000 |
| 2033 | 2016.1.01013.S | 38 | Testing a New Mode for Cloud Collapse in Galaxy Centers | The vast majority of dense gas in the Milky Way is in the Central Molecular Zone (CMZ, central 500 pc of the Galaxy) and most of the star formation in the CMZ is confined to gas streams about 100 pc from the Galactic center. These gas streams are on eccentric orbits that pass by the bottom of the Galactic gravitational potential well at Sgr A*. Initial investigation suggests that pericenter passage by Sgr A* may induce tidally-driven compression of clouds and subsequent star formation further downstream. This new mode of cloud collapse could give us an absolute timeline for star formation, with t= 0 occurring at pericenter passage on the streams, a fourth dimension for studies of star formation. We propose to obtain maps of the most structured cloud approaching pericenter. We outline three testable predictions of the tidally-driven cloud collapse scenario, which precludes current active star formation in the cloud. The countervailing scenarios predict none of these signatures, and instead predict star formation activity. We will perform the first detailed observational test of cloud collapse by tidal compression where the influence of the tidal field is the strongest. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-05-19T00:00:00.000 |
| 2034 | 2018.1.00657.S | 244 | What is the role of molecular gas when galaxies transition from blue to red? | The processes that cause the transition of galaxies from actively starforming to quiescent objects are still poorly understood. Galaxies in Hickson Compact Groups (HCG) are ideal objects to study this topic in a dense environment. Infrared (IR) colours are very powerful to find transitioning galaxies from underpopulated regions (canyon or IR Transition Zone) in the IR color space that indicate a fast transition from star-forming to quiescent. For a sample of transitioning HCG galaxies with CO(1-0) data we found clear evidence for a drastic decrease in the the star formation efficiency (SFE) and in the molecular gas fraction from active to transitioning galaxies (Lisenfeld+2017). However, it is still unclear what causes the decrease and perturbation of the molecular gas. Interactions with neighboring galaxies, intragroup gas and shocks causing turbulence are the suspected reasons. Here, we propose to map a small sample of southern canyon/IRTZ galaxies with the lowest SFE in CO(2-1) in order to derive a detailed image of the molecular gas distribution and kinematics that will allow us to find out whether tidal processes or interaction with intragroup gas is the dominant cause. | Merging and interacting galaxies | Galaxy evolution | 2020-03-06T10:26:13.000 |
| 2035 | 2013.1.00126.S | 9 | Defining the Neutral Material which Survives to within 0.1 parsec of the Galactic Supermassive Black Hole | Previous observations of hydrogen recombination lines toward the Galactic center detected ionized mini spiral arms, which appear to be material that is gravitationally accreted toward the Galactic supermassive black hole SgrA*. The new capabilities offered by Cycle 2 ALMA in band 9 allow us to probe the very hot neutral counterpart in the very central region. By observing the spatial distribution, the velocity, and the linewidth of this gas, we will determine how closely the hot neutral material can approach SgrA*, without being ionized, and to constrain the excitation conditions of this material within a ~0.1 pc radius. The optimal tracer of this material is multiple, highly-excited molecular transitions, which will better differentiate zone of different excitations, and provide more information on the kinematics of the accretion flow than observations of the hydrogen recombination line. | Galactic centres/nuclei | Active galaxies | 2016-09-25T05:58:26.000 |
| 2036 | 2015.1.00078.S | 15 | The jet-launching mechansim in HD101584 | One of the most challenging, but still unresolved, problems in stellar astrophysics is the transformation of ordinary stars into extra-ordinary planetary nebulae (PNe). Stars that are essentially spherical until the asymptotic giant branch (AGB) suddenly develop high-velocity jets, and on timescales of the order 100 years evolve into objects of great geometrical complexity. It is suspected that the complex outflows seen in proto-PNe are produced through transient interactions with a binary companion - but the mechanism is hotly debated. We have obtained ALMA data that strongly suggest that HD101584 went through a common-envelope evolution about 500 years ago, where the released orbital energy was not enough to drive the energetic outflow in the form of a jet. Another process must augment, or even dominate, the ejection. We propose here very-high-angular resolution data to study the properties of the central region where most of the mass resides, and the jet is launched. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2017-09-22T11:46:03.000 |
| 2037 | 2022.1.00482.S | 222 | ALMA CO-CAVITY: Molecular Gas in Void Galaxies | Here we introduce ALMA CO-CAVITY, the first survey to shed light onto the detailed molecular gas properties of void galaxies. It is built on a large well selected sample from the CAHA Observatory Legacy project called CAVITY, which will allow statistically significant conclusions on the properties of galaxies in voids thanks to optical IFU data for 300 void galaxies. Here we aim to observe CO(1-0) emission with resolutions better than 1 kpc for 41 star forming void galaxies with M* > 10^9 Msun, already with optical IFU data and HI information from the literature. With data for this large number of void galaxies, we will draw conclusions for the first time of the molecular gas properties as a function of stellar mass, morphological type, void-centric distance, and SF activity, among other properties. With the CO data we will characterize the molecular gas morphology and kinematics of void galaxies, as well as the build-up of stellar mass and quenching mechanisms. We aim to obtain resolved Kennicutt-Schmidt relations to resolutions better than 1 kpc, as well as SFE, Mmol/Mstar, and Mmol/MHI, and compare them to samples of non-void galaxies. | Surveys of galaxies | Galaxy evolution | 2024-09-20T14:57:39.000 |
| 2038 | 2018.1.01311.S | 2 | Search for the Keplerian Disk in the Protostellar Object B335 | B335 is a well-known star-forming region in an isolated condition without influences of other protostellar activities, and its physical and chemical character has extensively been studied as an ideal testbed of theories. In this source, the infall motion is known to be dominant near the protostar, and no rotation motion has been reported so far. With the ALMA observation at a 0.1" resolution, we have recently discovered the rotation motion toward this source for the first time, using the lines of complex organic molecules (COMs). This rotation can be explained by the infalling-rotating envelope model rather than the Keplerian motion. Although the Keplerian disk seems to be very small, its identification will be very important for the understanding of disk-formation processes. The main goal of this proposal is to identify the small Keplerian disk expected inside the infalling-rotating envelope traced by COMs. By resolving the COM emission, we will approach to the innermost structure of B335 where the disk should be being formed. | Low-mass star formation, Astrochemistry | ISM and star formation | 2021-01-09T09:31:51.000 |
| 2039 | 2017.1.00273.S | 116 | A unique and massive z=4.3 protocluster from the South Pole Telescope 2500 deg^2 survey | We propose to obtain deep line spectroscopy and continuum imaging towards the densest protocluster system discovered so far, SPT2349-56 at z=4.3. This system has been recently confirmed, using ALMA in cycle-4, having 13 ULIRGs/SMGs detected in dust-continuum and 9 detected in CO emission within 20" (integrated SFR of ~10^4 Msun/yr). Since it was found in a blind 1.4-mm survey of 2500 deg^2, it is unlikely there are many other systems like these in the entire sky. The proposed observations are thus essential to obtain an unbiased, coherent census of galaxy population in this truly unique protocluster field. Our main goals are to (i) characterize the environment, by identifying all line emitters down to 0.2mJy over the full LABOCA-detected structure. Given the high density of ULIRGs already detected, we expect to detect a plethora of fainter CO emitting galaxies at z=4.3. Along with our rich complimentary data, this proposal will enable a full characterization of the protocluster galaxy properties (gas, dynamical and stellar masses; multi-line diagnostics of the ISM). | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2020-02-28T00:00:00.000 |
| 2040 | 2013.1.00031.S | 17 | Are Close Binaries Formed through Disk Fragmentation? | Over 50% of sun-like stars are found in binary/multiple systems. Their formation is thought to occur during the early stages of the star formation process, but the formation mechanism remains unclear. The most likely possibilities are either disk fragmentation or turbulent fragmentation with dynamical evolution. To understand protostellar multiplicity, we have conducted a VLA 8 mm survey of all protostars (N~80) in the Perseus molecular cloud (d=230 pc) at a resolution of 0.3" (70 AU). With this unprecedented survey, we identified 17 close proto-binary systems with separations less than 500 AU, and of these, 14 are new discoveries. While these detections are significant, the VLA data do not convey their formation mechanism. Therefore, we propose to use ALMA to observe dust continuum and molecular line emission (C18O, 13CO) toward these 17 sources to determine if these sources have circumbinary disks in the apparent dust continuum and we will use the molecular line maps to determine if the disks are rotationally-supported. This sample is large enough to reveal general trends as to whether or not binaries typically form via disk fragmentation or turbulent fragmentation. | Low-mass star formation | ISM and star formation | 2017-01-08T07:14:44.000 |
| 2041 | 2021.1.01398.S | 545 | ACA Monitoring of Event Horizon Telescope (EHT) targets during the April 2022 EHT Campaign | The Event Horizon Telescope (EHT) observations will be carried out in Cycle 8, with the aim of resolving black hole shadows and jet launching regions in AGNs. These are expected to be observed over a 12-day period in March-April 2022, using several ~5-15 hr observing runs, triggered based on weather and telescope readiness, i.e. individual sources will be observed over several days with unpredictable gaps in daily coverage. Here we propose daily ACA monitoring of four sources: SgrA*, M87, 3C279, and CenA - during the 2022 EHT campaign. The primary goals of this proposal are to obtain: (a) better than 10% absolute flux calibration (per daily epoch) for all sources in the EHT observing runs (via bootstrapping); (b) constrain the origin of variability (e.g. proper motions vs relative brightening of individual components, or hot-spot orbits in Sgr A*) seen in EHT images on individual days using the argument of spectral variability; (c) a better comparison with the multi-wavelength (cm to X-ray) campaign (EHT private communication). Overall, these observations will lead to a significantly better, and perhaps crucial, understanding of the physical mechanisms on event horizon scales. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2023-03-22T20:35:21.000 |
| 2042 | 2017.1.00377.S | 905 | Exploring the mid-IR SED of high-mass YSOs | Despite their importance, there is still no solid diagnostic tools to classify massive young stellar objects (YSOs) according to their evolutionary stage. The most promising evolutionary indicator is the bolometric luminosity to envelope mass ratio. However, this method is severely hampered by the poor resolution of IR observations, which limit the accessible scales to those of entire proto-clusters. Observationally, very little is known about the spectral energy distribution of individual YSOs: measurements of single members of a proto-clusters are feasible only at long wavelengths thanks to radio/(sub)mm interferometers. We propose here a novel approach to investigate the mid-IR properties of single members of proto-clusters through ALMA observations. We will observe lines sensitive to the IR radiation field from 11 to 45 micron in a sample of well known and characterised massive clumps. These data will allow us to confirm the relation between the presence of these transitions and the corresponding pumping IR field and to use these lines as proxy of the IR emission to indirectly estimate the mid-/near-IR monochromatic luminosities of each member of the protocluster. | High-mass star formation | ISM and star formation | 2019-02-22T19:44:31.000 |
| 2043 | 2018.1.01246.S | 55 | Deriving True Star Formation Rates in Dust-Obscured Starburst Galaxies | Hydrogen radio recombination lines (RRLs) are powerful tracers of the physical properties of the ionized gas in dust embedded regions. They are extinction-free direct probes of ionizing photons, and thus the far-ultraviolet luminosity of OB stars in star forming regions. We propose to observe H26a and H41a in two local starburst LIRGs (NGC3256 and IIZw096) and exploit their dust penetrating power to (1) estimate the true star formation rate (SFRs) using a direct tracer that is dust extinction free, (2) obtain accurate dust extinction maps by comparing the SFR maps based on the RRLs and dust-corrected H-alpha, and (3) compare the radiation from the RRLs and the dust heating derived from the continuum emission in the submm and mid-infrared to investigate star formation with different time scales. The proposed observation will produce a definitive picture of the extreme environments of star formation deeply embedded in the dust and provide a reliable calibration of the gold standard H-alpha SFR indicator, which is especially critical in the JWST era for exploring high redshift galaxies. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2019-12-24T10:59:53.000 |
| 2044 | 2016.1.00830.S | 37 | The Orcus-Vanth System: A Rosetta Stone for accretion in planetary systems | The dwarf planets in the Kuiper belt provide one of the most compelling cases of the breakdown of the simple theory of pairwise accretion. The formation of these large rock-rich dwarf planets through coagulation of the population of small low density near rock-free objects appears difficult. Alternative accretion theories predict a wide variety of behaviors of the size-density relationship through the small body-large body transition. The Orcus-Vanth binary system is uniquely suited to determining the density behavior through this transition and pointing to the accretion history of the solar system. The new higher resolution capabilities of ALMA in Cycle 4 allow us to use resolved thermal radiometry to measure the individual component sizes and, the unique capability of highly accurate relative astrometry over moderate angles will let us determine the astrometric wobble of Orcus induced by Vanth to measure the individual component masses, yielding simultaneous densities of two of these transitional objects and a chance to determine how solid bodies in planetary systems form. | Solar system - Planetary surfaces | Solar system | 2018-01-13T05:10:16.000 |
| 2045 | 2013.1.00725.S | 0 | Interferometric mapping of magnetic fields in the W43 mini-starburst | The immediate objective of this proposal is to map polarized dust emission in the 6 most intense clumps in the W43 mini-starburst at sub-arcsecond resolution, in band 6, with ALMA. W43 has been found to contain two of the largest cloud groups of the first Galactic quadrant at the interface of the Galactic bar with the inner Scutum spiral arm. From the whole region, the W43-MM1 is the largest clump likely forming a large cluster of high-mass stars. W43-MM1 has already been mapped in polarization with BIMA and recently by the SMA at 4 and 2 arcsec resolution respectively. Both results suggested pinched morphologies for the field and slightly super-critical equilibrium conditions. Thus, we would like to extend these results to whole mini-starburst by mapping our sample with ALMA to derive the magnetic field morphology and to estimate the field strength on the plane of the sky allowing us to evaluate the dynamical equilibrium of each clump. Additionally, we will get, as a by-product, an exquisite Stokes I continuum image for each source in our sample, which we will use to study the fragmention process inside the clumps selected in the W43 mini-starburst. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-10-28T11:02:59.000 |
| 2046 | 2021.1.01580.S | 3 | Mapping the gas flow around the gap carving planet HD97048b | The kinematic detection of a planet carving a dust gap in the disc surrounding HD 97048 demonstrated the planetary origin for at least some of the gaps commonly observed in discs. The next step is to study in detail the physics of the planet disc interaction. Here we propose to observe HD 97048 in several molecular tracers sampling the vertical structure of the disc to map the 3D structure of the gas flow around the planet. We request 0.1" spatial resolution and 60m/s velocity observations in the band 7 transition of 12CO, CS, and HCN. Together with archival 13CO at similar resolution, they will offer the most comprehensive view of the gas flow around a young planet to date. These observations will allow us to refine the constraints on the mass of the planet, to disentangle different dynamical processes in its vicinity, and to potentially detect the first chemical signature of an embedded planet. | Disks around low-mass stars | Disks and planet formation | 2024-03-03T19:39:10.000 |
| 2047 | 2023.1.00548.S | 0 | The complex feeding-feedback cycle of Abell 2495: where is the molecular gas? | We request ALMA observations of a cluster of galaxies whose Chandra, VLA and MUSE Halpha observations unveiled cooling and feedback signatures but also intriguing spatial offsets (few kpc) between the X-ray emission peak, the central radio galaxy, and the Halpha ionized component, all linked by a dust filament. This poses the question of how the separation of the low entropy intra-cluster medium, active galactic nucleus (AGN) and cooled ionized component occurred in the context of the feeding-feedback cycle of this cool-core cluster. We aim at mapping the distribution of the molecular gas traced by CO 1-0 emission and studying its kinematics in order to determine if the AGN is still being fed by cold gas despite the apparent detachment of the supermassive black hole from its most likely fuel sources, or if the feeding-feedback cycle has been interrupted. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2025-10-23T22:41:08.000 |
| 2048 | 2016.1.00087.S | 100 | N+ in the most luminous SMGs in the Universe at z>4 | From a 500 degree^2 survey, HATLAS has used colour selection in the SPIRE bands to find the reddest sources likely to lie at the highest redshifts. From these we have identified the 2 sources which are unlensed, involved in a clear major merger, and represent the most luminous galaxies known in the Universe at z>4. We propose to observe at high resolution (0.24'') N+ along with CO to combine with existing C+ observations to map the metallicity in these systems and diagnose their ISM properties, seraching for the mechanisms controlling the extremes of star formation that can be sustained. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2018-05-30T18:11:44.000 |
| 2049 | 2012.1.00994.S | 4 | Completing the redshift distribution in a flux limited sample of strongly lensed SMGs from the South Pole Telescope Survey | Recent ground and space-based multi wavelength (sub)millimeter surveys covering hundreds of square degrees have discovered a large number of strongly lensed, ultra-bright submm galaxies (SMGs). The largest of these, by nearly an order of magnitude at present, is the South Pole Telescope (SPT) survey, which covers 2500 square degrees. Its 1.4mm detection wavelength ensures a uniform source selection function across z=1-8. Both aspects make SPT the ideal survey to uncover substantial numbers of the elusive z>4 SMG population. We have been granted ALMA observing time in cycle 0 to determine the redshifts of 26 SPT sources via frequency scans in the 3mm band. This survey is a large success with 45 detected line features, 16 unambiguous redshifts at z>3 (>60% of the sample) including two sources at z=5.7 which places them among the highest redshift SMGs discovered so far. Our sample has a mean redshift of z~3.5 (compared to z~2.5 for radio identified SMGs) and our data indicates that the redshift distribution cloud be almost flat between z=2.5-4.5. For 8 sources in our sample, however, we only detect a single line feature. In these cases we can only narrow the line identification to two plausible CO transitions which hampers the interpretation of our results. In this proposal we ask to establish their redshifts via observations of a second CO line in band 6. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-01-28T11:45:52.000 |
| 2050 | 2016.1.01188.S | 42 | Unveiling the Galaxy Formation Sequence | The spectacular ALMA observations of the z=3.04 Herschel galaxy SDP 81 revealed a collapsing disk containing a galaxy-building starburst. However, the short time needed for the disk to collapse suggests that SDP 81 may only represent one phase in the galaxy-formation process. We propose to observe a sample of eight of these galaxy-building starbursts in Band 6 in both line and continuum with a resolution of 0.05 arcsec, in a strategy designed to produce the same science results as the SV observations of SDP 81 but much more cheaply. Our observations will provide maps of the dust and gas in these galaxies, and the kinematics will allow us to estimate each galaxy's mass, the gas, stellar and dark-matter fractions, the relative importance of interactions and rotation; and, in the cases where there is s disk, determine whether the disk is collapsing. In general, our observations will take the study of these galaxy-building starbursts from one, possibly unrepresentative object to a statistical sample (although still of modest size), allowing us to make a first attempt at disentangling the different phases of the galaxy-formation process. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-12-07T20:27:48.000 |
| 2051 | 2019.A.00023.S | 20 | Confirmation of a black hole at z=10.154 | With this proposal, we propose to unambiguously confirm the most distant black hole to date, located at z=10.15! We rely on a successful selection technique that already confirmed a z=5.55 source out of four candidates from our pilot study in the GAMA09 field (Drouart et al, accepted). We now have a short window of opportunity to publicize with a high impact publication, as well as a press release, a new distance record for black hole, breaking the symbolic z=10 limit. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2020-12-19T19:41:07.000 |
| 2052 | 2017.1.01023.S | 34 | Resolving molecular outflows in HH137 and HH138 | We would like to observe the 12CO(2-1), C18O(2-1), SiO(5-4) and N2D+(3-2) lines towards the Herbig-Haro objects HH137 and HH138, located in the Carina region at 2.2 kpc, using Band 6 receiver of the ALMA interferometer. Our aims are to disentangle in some detail the morphology of the molecular outflow previously detected in the H2 image obtained with Gemini and in the CO(3-2) line obtained using APEX, to know the velocity structure of the gas, to investigate the presence of non-straight morphologies, precession and wiggling effects in the outflow. Also, to investigate the collision region between the dense clump and an arc-like structure seen at 4.5 micron linked to the HH objects, and test the proposed scenario for these objects. | Outflows, jets and ionized winds, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-04-20T18:26:24.000 |
| 2053 | 2021.1.00715.S | 8 | Formation of low-mass dense cores from a web of filaments | Dense cores are the direct progenitors of protostars, and hence their formation mechanism is very important to understand the origin of the stellar initial mass function, as indicated by the resemblance to the core mass function (CMF). So far, observational studies of CMF are quite incomplete particulary in the very low-mass (< 0.1 Mo) regime. Sampling a large number of low-mass cores requires high sensitivity, high resolution, and extensive coverage. Surveying large area with ALMA toward nearby cluster-forming region is the best approach for this purpose. We intend to carry out a survey of Corona Australis cloud for dense low-mass cores by the 12m array. A wide area of the cluster-forming cloud has been surveyed by ACA standalone, and it demonstrates a complex web of filaments with prestellar cores. Compact low-mass cores are, however, heavy contaminated and seem to be merged with each other, due to the highly clustering distribution and poor spatial resolution. Higher resolution observation by the 12m array can overcome this problem, and make it possible to investigate the CMF down to 0.01 Mo. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-12-27T02:12:47.000 |
| 2054 | 2016.1.00778.S | 20 | Spatially Resolving the Molecular Gas and Dust in the Highest Redshift HI-detected Galaxy | We propose to image the molecular gas and dust in the highest redshift HI detected galaxy in emission. While the optical image shows a relatively undisturbed strongly barred galaxy, its high star formation rate and cold gas properties depict a more complex picture. The total amount of cold gas exceeds 10^11 Msun, with comparable amounts of HI and H2. The VLA HI image shows that the atomic gas is highly asymmetric within the disk and extends far beyond it to the south. The LMT CO(1-0) spectrum shows a narrow component consistent with the HI width and a symmetric broad faint component, suggestive of an outflow. ALMA CO(3-2) and HCN(2-1) observations will provide the distribution, kinematics and density of the molecular gas. The high gas fraction and star formation properties makes it an ideal analog to the clumpy galaxies seen at higher redshift. This study will result in the first images of the cold hydrogen content (both atomic and molecular) for a galaxy beyond the local Universe. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-02-01T20:04:13.000 |
| 2055 | 2017.1.01330.S | 83 | Dust Trapping in the Substructures of Protoplanetary Disks: A Pilot Program at 3 mm | Substructure in protoplanetary disks is fundamental to allow the transformation of disk material into planetary systems. Theory predicts that without substructure in the gaseous disk component, large solids are lost due to radial drift, impeding planetesimal and planet formation. If disk inhomogeneities exist, they create localized pressure enhancements that can effectively trap drifting solids, evolving the particle-size distribution to include large grains. This idea can be tested observationally, by spatially constraining the distribution of solids of different size at high spatial resolution. In Cycle 4 we were awarded an ALMA Large Program at 1.3mm to study substructure in 20 protoplanetary disks. These upcoming observations will constrain the spatial distribution of ~1mm particles down to 6AU scales. Here we propose ALMA 3 mm observations with matched spatial resolution and sensitivity for a subset of 4 bright disks. This proof-of-concept program will probe particles 3 times larger in size, allowing us to constrain the particle-size distribution in ~6-10AU scales, and test if particle trapping occurs in the small-scale substructure of protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2019-12-27T23:57:02.000 |
| 2056 | 2016.1.01140.S | 84 | Disentangling the Origin of the Millimeter Excess in Nearby AGNs toward Understanding of the Nature of AGN Coronae | By using the ALMA Bands 3, 4, and 6, we disentangle the origin of the millimeter excess in the nearby Seyferts NGC 985 and IC 4329A which is established by the past observations. It is possibly coming from the disk coronae. By utilizing the three ALMA bands, we unveil the nature of the AGN coronae. Scientific Impact: The possible process for the excess is either synchrotron radiation from thermal or thermal+non-thermal accretion disk corona. If we can disentangle these models, it is observationally the first case in either case and we can determine the size, the magnetic field strength, and the heating mechanism of the coronae. Why do we need ALMA?: On the basis of our ALMA Cycle-3 observations of NGC 985 at 85-150 GHz, the excess has been confirmed to be ~3 mJy at ~100 GHz but with no break. With additional band-6 data, we can disentangle the scenarios. For IC 4329A, ALMA archival data shows 13 mJy at 230 GHz and we previously obtained 66.8 mJy at 1.4 GHz and 11.4 mJy at 8.4 GHz. Thus, this object also has the excess. To unveil the origin of the excess, new ALMA continuum spectral data are necessary. ALMA's spatial resolution can exclude dust contamination. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-04-27T06:01:48.000 |
| 2057 | 2019.1.00526.S | 10 | A new molecular gas mass tracer in galaxies: a first test in the local Universe | A full accounting of H2 gas in galaxies is fundamental for understanding their star formation activity and thus their global evolution. Since H2 molecules do not emit radiation captured by radiotelescopes, CO is frequently used as a tracer as it exists where molecular gas resides and has bright rotational transitions in the (sub)mm wavelength regime. However, its utility as a tracer for extragalactic objects has been debated the last decade. We propose ACA observations to compensate the missing flux in our A-rated project. We aim to image [CI] 1-0 in a local starburst for providing a benchmark over a significant range of average thermal, density, and dynamical states of H2 gas, testing if [CI] is the best tracer for studies related to the molecular gas content. The proposed observations will allow us to i) compare the utility of CI versus CO as a tracer, ii) examine cosmic-ray chemistry, iii) use the CO SLED (up to 13-12) and CI 1-0, 2-1 lines to constrain power sources in heating ISM, iv) search for any starburst/AGN-induced molecular gas outflows, v) spatially resolve the submm continuum at 480 GHz, and vi) test CI as a tracer for rotational curves of galaxies at high-redshift. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG), Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2021-01-08T15:23:43.000 |
| 2058 | 2013.1.00319.S | 6 | The life cycle of dust and gas: CO observations of AGB stars in the Large Magellanic Cloud | The life cycle of dust and gas is one of the main topics in modern astrophysics. Both intermediate mass Asymptotic Giant Branch (AGB) stars and Supernovae are believed to be important contributors of dust and gas to the interstellar medium, although the relative contribution remains uncertain. However, we lack evidence of how the gas mass-loss rate of AGB stars depends on luminosity and in particular on metallicity. A sample of 4 carbon-rich and 2 oxygen-rich very dusty AGB stars in the LMC have been selected for which detailed radiative transfer modelling strongly suggests that we will be able to detect the CO J=2-1 and J=3-2 lines, and for which dust mass-loss rates are available.The observations will result in the first direct determination of the gas mass-loss rate in extragalactic AGB stars by modelling of the CO lines, and yield, through the expansion velocity, the essential parameter for an accurate determination of the dust mass-loss rate. The observations will also provide a critical test to the predictions of dust-driven wind theory on how expansion velocity, dust-to-gas ratio and mass-loss rate depend on metallicity. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2016-08-18T11:50:08.000 |
| 2059 | 2022.1.01363.S | 0 | Molecular Gas content of a ULIRG at z>7 | While we have made great progress characterizing galaxy growth over the first billion years of the Universe, there is still a fundamental gap in our understanding. Stellar mass content studies as well as star formation rate estimates both coincide in showing that early galaxies grew very rapidly, but what sustains this growth? Are high-z galaxies particularly efficient at forming stars or do they have particularly large molecular gas reservoirs fueling their growth? Answering this question requires studying the molecular gas content of galaxies, and at z>7, high-J CO lines are our best bet. Recent samples of bright [CII] detected galaxies have opened the door to such studies but they still remain very challenging due to how faint CO lines are expected to be. Here we propose a first study of the molecular content of a galaxy at z>7 through the CO(7-6) line. Our source is a ULIRG, bright in [CII], with enhanced metallicity, and dust content (compared to galaxies at similar redshift). This combination implies a higher CO content, and dust shielding that prevents CO photodissociation. This is one of the best sources for a first study of the molecular gas content in a galaxy at z>7. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-09-12T17:53:14.000 |
| 2060 | 2016.2.00094.S | 117 | Multi-transition Analysis of Molecular Gas in the Luminous Merger NGC 3256 | We propose ACA observations of the luminous infrared galaxy NGC 3256 to combine the data with our existing 12 m-array datasets and facilitate multi-transition excitation analysis for extended emission. NGC 3256 is a merging galaxy with active star formation that is most bolometrically luminous within z=0.01. We have been observing the galaxy with ALMA since Cycle 0, targeting the merger gas dynamics, evolution of the two nuclei, the dual outflows that we discovered, and the star-forming interstellar medium. However, some of the data do not have short-baseline information making it difficult to conduct multi-line excitation analysis with line ratios for the physical conditions of extended molecular gas. By supplementing ACA data to several lines, this program aims to reveal the physical conditions of the star-forming molecular gas in the merger disk and the extended molecular outflow from the northern merger nucleus. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2018-08-29T14:27:22.000 |
| 2061 | 2015.1.00661.S | 26 | Star formation outside of powerful AGN host galaxies | In the last decade several cases have been discovered where massive molecular gas reservoirs were found at <100 kpc distance from an AGN, residing in a gas-rich companion galaxy. Thus it is possible that in a fraction of massive local galaxies a part of their stellar mass was formed outside of their host galaxy in a close starbursting companion and was later incorporated via mergers. We here propose to do ALMA observations of the z=2.8 quasar SMM J04135+10277 and the z=2.6 radio galaxy TXS0828+193. Previous CO observations discovered very massive gas reservoirs outside of their host galaxies, while no such reservoirs were found in the host galaxies themselves. In case of SMM J04135 a companion galaxy is detected in IRAC bands, while in case of TXS0828 the CO emission does not have a counterpart in optical and in near-IR wavelength. Our goals are: 1) To study the structure and distribution of the submm/mm emission and determine the star formation of the companion galaxies; 2) To determine structure and the excitation properties of the molecular gas; The study of these interacting systems is crucial to understand the growth and hierarchical build-up of galaxies. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-08-04T14:32:46.000 |
| 2062 | 2023.1.01643.S | 0 | Estimating the cosmic-ray ionisation rate across OMC-2 and OMC-3 | The ionization fraction is a key property of the ISM regulating the coupling gas-magnetic fields and chemistry during star-formation. In the cold and dense molecular gas of the ISM, the ionization is driven by H3+, which depends on the Cosmic Rays Ionisation Rate (CRIR). Over the years, the standard value of CRIR~1e-17 s-1 has been challenged through the observations of multiple tracers as proxies of H3+, which cannot be detected at mm wavelengths. Recently, o-H2D+ (the main deuterated form of H3+) has been proposed as the best alternative to estimate the CRIR in dense regions. Observable at high-resolution only in ALMA Band 7, o-H2D+ has been explored in high-mass clumps, but never on parsec scales. This project aims to determine the CRIR with o-H2D+ from clouds to clump scales. For that we propose new ACA stand-alone observations in Band 7 along the OMC-2/3 regions covering a wide range of column (~5E21-5E23 cm-2) and volume (1E5-1E7 cm-3) densities. These observations will set strong constrains to the expected correlations between CRIR, N, and n predicted by theoretical models. These results will provide a first direct determination of ionization fraction at cloud scales. | Astrochemistry | ISM and star formation | 2024-10-04T15:23:22.000 |
| 2063 | 2022.1.01354.S | 10 | Looking for disk fragmentation in a nearby high-mass face-on disk | G327.3-0.6 is a very luminous high-mass star-forming hot core at a distance of 3.3 kpc, nearby for a high-mass source. Analysis of previous ALMA data and ancillary IR data revealed that there is a very compact outflow, previously undetected in single-dish observations, and, in spite of a very large visual extinction (Av=10,000), an IR source was seen toward the center down to wavelengths as short as 3.6 um. The most likely scenario is that we are looking down to the powering source through the cone of the outflow (detected by ALMA), which would allow us to map a face-on disk in detail. ALMA spectral fitting reveals a source size of 1500 AU. Hence we propose the highest resolution observations to search for disk fragmentation and spiral structures as predicted by models. The unique geometry will allow multiwavelength studies from the IR to the mm, which can largely promote modelling. G327.3-0.6 could become a prototypical disk source for high-mass stars, as TW Hya is for low-mass stars. | High-mass star formation | ISM and star formation | 2024-06-12T16:41:57.000 |
| 2064 | 2019.1.00036.S | 66 | Probing the Over-massive Black Hole Populations in Compact, High-Dispersion Galaxies | The distribution of over-massive black hole mass in compact, high-dispersion galaxies is surprisingly not yet well understood. Their BH mass-galaxy scaling relations are subjected to large positive scatter towards the high-mass hots (M ~ 10^11 Msun) and black hole mass (M_BH > 10^9 Msun) regimes. The systematic differences in the scaling relations between the compact, high-dispersion galaxies and the giant ellipticals/bright cluster galaxies would also imply that the BHs in the two types of galaxies grew in different ways. To determine the true distribution of over-massive BHs and constrain their mass scaling relations to the host properties, a set of intermediately high-spatial-resolution observations of CO(2-1) emission of their circumnuclear gas disks (CNDs) is required. With these observations, we can (1) test the feedback paradigm and (2) anchor studies of the SMBH-host galaxy relations which use molecular gas. In this way, an investment of ALMA time and a homogenous technical/model approach can help reveal more about the complex formation histories of the most massive galaxies in our universe. | Galactic centres/nuclei | Active galaxies | 2022-07-01T22:38:56.000 |
| 2065 | 2019.1.00863.T | 49 | Unveiling the First Short GRB Millimeter Afterglows with ALMA | Short gamma-ray bursts (SGRBs) are relativistic explosions which originate from the mergers of two compact objects (NS-NS/NS-BH). Such merging systems are also at the forefront of transient astrophysics, with the recent multi-messenger discovery of GW170817. Modeling of SGRB afterglow emission from the radio to X-ray bands provides a unique way to probe the burst basic explosion properties: the energy scales, circumburst densities, and jet opening angles. These properties not only provide critical insight into merger environments, but also serve as a vital baseline for comparison to properties inferred from future gravitational wave events. In the millimeter band, the faint and rapidly-fading afterglows of SGRBs require the sensitivity and dynamic scheduling of ALMA. Here, we propose to use ALMA TOO observations to identify and monitor, or place deep limits on the millimeter afterglows of 2 SGRBs in Cycle 7. Our proposed observations will be sensitive to SGRBs over a wide range of densities and jet opening angles. Our search will offer hundred-fold improvement over previous millimeter searches with other facilities, and any detections would be a milestone in SGRB studies. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2022-11-26T23:13:41.000 |
| 2066 | 2018.1.01173.S | 5 | Witnessing the formation of planets in the TW Hya disk | Planets are formed from dust and gas in protoplanetary disks (PPD) around young stars. A young planet is surrounded by a circumplanetary disk (CPD) in the PPD and is one of the promising objects that we can directly detect. However, the CPDs have not been found at (sub)millimeter wavelengths to date. Recently, we discovered a millimeter blob at a radius of 52 au in the TW Hya disk. This is the first detection of an asymmetric ~au scale substructure of millimeter continuum emission associated with the PPD. Although the blob can be well-explained by a CPD around a Neptune mass planet, a dust clump accumulated in a small vortex is not ruled out. In this proposal, we aim at deep observations at ~1.5 au resolution to unveil the nature of the millimeter blob. In addition, a candidate CPD associated with the 25 au gap will be searched. Once the blob is confirmed to host the central "hot spot" requiring internal heating sources such as viscous heating and irradiation by the central planet, this will offer the first direct evidence of a forming planet in the CPD and will place significant constraints on the planet formation processes. | Disks around low-mass stars | Disks and planet formation | 2022-11-11T22:55:13.000 |
| 2067 | 2013.1.00694.S | 23 | Mapping Ionization Processes in Protoplanetary Disks with Chemistry | Midplane ionization in protoplanetary disks plays a vital role in setting turbulent (MRI) and thermal physics, and drives gas-phase pathways towards chemical complexity and deuteration. Ionization sources include stellar photons, cosmic rays (CRs), and short-lived radionuclides (SLRs). Each process has widely differing energies and physical regimes. X-rays dominate the inner 50 AU, whereas CRs and SLRs are important further out. Molecular ions present in the cold gas as seen in sub-mm emission allow us to trace ionization in the dense midplane. Within the CO snow line, HCO+ is the preferred ionization tracer, whereas N2H+ provides insight at larger radii. As a result, these lines can be used in tandem to measure ionization on all radial scales. Guided by our work on ionization processes, we have isolated IM Lup as the ideal target for a resolved ionization study with ALMA. The IM Lup system has a gas-rich and extended (R~700AU) disk, along with an X-ray stable star. The proposed set of observations allows us to directly trace midplane ionization and its source as a function of distance from the parent star via sensitive H13CO+ and N2H+ resolved observations. | Disks around low-mass stars | Disks and planet formation | 2016-03-26T13:38:23.000 |
| 2068 | 2023.1.01576.S | 0 | Oxygen enrichment in the Small Magellanic Cloud | Isotopic abundance ratios provide a powerful tool for tracing stellar nucleosynthesis, evaluating the effects of stellar ejecta, and constraining the chemical evolution of galaxies. While the 18O/17O isotopic ratios, representing ejecta from massive versus less massive stars, have been extensively studied in the Milky Way and the Large Magellanic Cloud, their determination in very metal-poor galaxies (less than 1/5 times the solar metallicity), such as dwarf galaxies and high-redshifted galaxies, has been much less conclusive. As one of the most metal-deficient star-forming galaxies in the Local Group, the Small Magellanic Cloud (SMC) represents an ideal prototype of such objects. To improve our understanding of the SMC's isotope ratios, we propose sensitive ACA observations of C18O (2-1) and C17O (2-1) towards N12A/LIRS36, the most prominent 13CO emitter in the SMC. The successful observations will constrain the 18O/17O isotopic ratio in the SMC for the first time, which can shed light on the oxygen enrichment in the SMC, benchmarking oxygen isotopic ratios of very metal-poor galaxies, and the dependence of 18O/17O isotopic ratios on metallicity. | Merging and interacting galaxies, Dwarf/metal-poor galaxies | Galaxy evolution | 2025-08-31T01:25:31.000 |
| 2069 | 2015.1.01528.S | 218 | AS2UDS : Clustering of ~1000 ALMA-identified submillimeter galaxies | We propose ALMA band-7 continuum follow-up observations of an uniformly selected sample of 533 submillimeter sources with S850 > 3.5mJy from our SCUBA-2 survey of the UKIDSS-UDS. We expect to precisely locate almost 1000 SMGs with S850 > 1mJy. With this unprecedented large number of SMGs with precise positions, our science goals are to 1) measure the angular correlation function and so derive the halo mass, building the evolutionary links between SMGs and other high-z galaxy populations and their local desendants, 2) test whether brighter SMGs are more likely to break up into multiple faint components, and derive intrinsic number counts, 3) precisely identify the counterparts in other wavelengths and so derive redshift distributions, in particular the form of the high-z tail. With a sample of ~1000 ALMA SMGs (~10 times larger than that of previously samples such as ALESS), we will measure the multi-wavelength properties of the population, redshift distribution and most critically their clustering, allowing us to properly link SMGs with their proposed descendants: luminous ellipticals. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2017-12-09T22:03:58.000 |
| 2070 | 2017.1.00487.S | 3 | Spatially resolved star formation in a high-z galaxy | High-redshift dusty star-forming galaxies are now beginning to be spatially resolved and imaged at ~100 pc scales, thanks to the fantastic sensitivity offered by ALMA. These observations reveal that star formation, as traced by warm dust emission, is extended and clumpy over the entire galaxy. The warm dust emission is converted into star formation rates, indicating global rates of > 1000 solar masses per year. However, this conversion implicitly assumes that the warm dust emission scales with star formation, which may or may not be true. We propose to use a Galactic star-formation tracer, water, to map the actual star formation across one resolved galaxy at z=3.179, AzTEC8, in three water transitions and at an angular resolution of 0.02" (~150 pc). These observations will directly reveal if the warm dust traces star formation or not, thereby opening up a new window for studying spatially resolved star formation at high redshift. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-05-11T14:11:05.000 |
| 2071 | 2016.1.00698.S | 41 | Unveiling the Most Distant Massive Galaxy Cluster | We propose to map the Sunyaev-Zel'dovich (SZ) effect caused by the intracluster medium (ICM) of the highest redshift (z=2.0+-0.07) genuinely massive (M>1e14 Msun; ICM temperature kT~6 keV) cluster of galaxies ever discovered. Our target, XLSSU J021744.1-034536, was discovered through its faint X-ray emission in the XMM-XXL survey, and its high redshift was confirmed through detections of the cluster red sequence in multi-band imaging and the Fe emission line of the ICM in deep XMM follow-up data. The arcminute-scale SZ effect has already been measured by CARMA at 30 GHz, further confirming the presence of hot gas. The existing, low-resolution X-ray and SZ data suggest that the cluster is undergoing a merger, but cannot reveal details within the cluster with any certainty. The proposed ALMA observations will provide the first high-resolution look at the morphology and dynamical state of the ICM in this cosmologically important system. At the same time, the data will demonstrate the potential of millimeter interferometry for mapping clusters at very high redshifts, where obtaining equivalent-resolution X-ray imaging is prohibitively expensive. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2018-02-23T02:34:59.000 |
| 2072 | 2016.1.00319.S | 225 | Comparing two externally irradiated protostars in Ophiuchus | Our own Solar System formed in the vicinity of at least one massive star, and it is therefore crucial to study the consequences of external irradiation on the properties of protostellar envelopes. We here propose studies of two protostars in Ophiuchus subject to different levels of external irradiation. In particular, we will study the temperature of their irradiated envelopes through observations of the excellent thermometer H2CO (formaldehyde), which will shed light on the respective contributions from internal and external heating. Single-dish observations show beam-averaged H2CO temperatures of 36 K and 16 K, respectively, in the two sources, which should cause a significant difference in the chemistry as a result of, for example, CO evaporation. The observations also target chemical differentiation between typical organic species (H2CO and CH3OH) and unsaturated hydrocarbon molecular species (c-C3H2) in the envelope, as these species show very different excitation properties in single-dish observations. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-04-06T23:30:36.000 |
| 2073 | 2016.1.01082.S | 29 | To what extent is the protostellar outflow HH 212 driven by collimated jets? | HH 212 is a text-book example of a jet driven protostellar outflow. Current jet-launching models predict that a wind driven component should be present, but as of yet, it has eluded conclusive detection in HH 212. We propose to use the stand-alone ACA mode of ALMA Cycle 4 in Band 6 to perform the first full-scale, high-sensitivity, short uv spacing, observation of HH 212 to map previously undetectable flux. With the new data we will perform mass-velocity (with optical depth correction), and position-velocity analyses to conclusively detect and study the wind componenet of HH 212, and in turn obtain a greater understanding of the kinematics of protostellar outflows in general. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-11-11T00:00:00.000 |
| 2074 | 2019.1.00877.S | 6 | How Hierarchical is Cluster Formation? A deep, high-resolution census of the G11.92-0.61 gas reservoir | A crucial open question is how (or even whether) the formation of a high-mass star is intrinsically linked to the formation of a surrounding cluster. Hierarchical cluster formation models differ on whether distributed subclusters contain high-mass protostars at early times or consist only of low-mass protostars (with high-mass stars forming only at late times and/or only in central hubs fed by filamentary accretion flows). We propose deep (5 sigma mass sensitivity 0.06 Msun, 10x deeper than the ALMA-IMF LP), high-resolution (0.2"~675 AU) ALMA 1.3 and 2.0 mm mosaics to obtain a census of star formation activity - including pre- and protostellar cores and (higher-mass) protoplanetary disks - throughout the 2.2 pc^2 extent of a normal cluster-forming cloud (the gas reservoir for the deeply embedded massive protocluster G11.92). We will combine the 1.3 and 2.0 mm ALMA data with existing 0.2" resolution VLA images at 3 and 0.9 cm to measure and model the SEDs of cluster members, and gauge their accretion activity using multiple 1.3 mm outflow tracers spanning a range in abundance and excitation. We will also make detailed comparisons with new AREPO simulations. | High-mass star formation | ISM and star formation | 2022-11-30T16:41:01.000 |
| 2075 | 2022.1.00406.S | 0 | CO polarization observations for investigating a new tool as a magnetic tracer | ALMA dut polarization observations have shown that dust grains are not always aligned with magnetic fields in protoplanetary disks. Scattering and dust alignment with other mechanisms play important roles in the dust polarization rather than dust alignment with magnetic fields. Therefore, we need to find another method to reveal the magnetic field structure in disks. Here, we propose to investigate the CO polarization produced by the Goldreich-Kylafis effect (G-K effect). The HD 142527 disk is the best target to detect CO linear polarization and investigate the G-K effect because dust grains as small as ISM are located in the south region of the disk and are aligned with the toroidal magnetic field. By comparing the CO polarization and dust polarization, we will resolve the ambiguity of whether the G-K effect produces the polarization parallel or perpendicular to the magnetic field. By applying this method to the northern region, we will reveal the entire magnetic field structure. This study will provide us with the fundamental idea of the relation between the G-K effect and the magnetic field in the disks. | Disks around low-mass stars | Disks and planet formation | 2025-01-24T00:00:00.000 |
| 2076 | 2021.1.00574.S | 0 | Constraining dust SEDs of ALMA-identified galaxies | We propose observations in Band 9 and Band 5 of 316 sub-mm galaxies from an ALMA Band 7 continuum survey in the UDS field. This large sample of ALMA-identified sub-mm galaxies comprises a complete and unbiased flux-limited sample, S_870>3.9mJy, across ~0.9 deg^2 survey field. The proposed Band 9 + 5 data, together with the high-quality Band 7 photometry, will significantly constrain the dust SEDs with an uncertainty of just 5% in T_d and 15% in L_fir (currently a factor of ~1.2-1.4 and 1.5-2, respectively). With well-constrained SEDs we will split the sources into subsets in L_fir, M_star, and redshift (~50 sources per bin) to identify bivariate trends of the sources in these key parameters. In this manner we will test if there are structural differences in the dust regions of sub-mm galaxies at different redshifts; address whether high-z sub-mm galaxies are systematically cooler than local ULIRGs and if this is due to lower M_dust and/or more compact sizes (sub-mm continuum sizes are available for half the sample); study whether SMGs form stars more efficiently than disk galaxies and examine the physics of star formation by deriving more precise SFR and gas surface densities. | Sub-mm Galaxies (SMG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 2077 | 2017.1.01689.S | 172 | Millimeter line variability in IRC +10216 with ALMA Compact Array. | The dynamical pulsation processes is the key to understanding AGB wind launching but is difficult to observe. The mm line variability has been found recently. Part of the line variation could be due to the pulsation dyhamics in the inner CSE. This offers the possibility to trace the elusive dynamical processes with mm monitoring. We have performed a systematic single dish monitoring of several millimeter lines toward the archetypal carbon star IRC +10216. Regular line intensity and line shape variations have been found, but need confirmation. Large differences in variation periods and phases and obvious velocity dependent phase delays in the varying line profiles remain unexplained. We propose to monitor the varying millimeter lines in this star with the smaller beam of ACA to achieve larger variation amplitudes and to confirm the peculiar variation behaviors. A series of 1.3 mm continuum and line observations with the ACA in standalone mode (once every month) are proposed to roughly evenly sample the infrared period of 630 day (in two years). This is the extention andd upgrade of an existing ACA monitoring in Cycle 4. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-11-17T21:38:40.000 |
| 2078 | 2021.1.00040.S | 0 | A Quest for the Progenitor System of Type Ia Supernova Remnant | Identifying the progenitor systems of Type-Ia supernovae, single degenerate or double degenerate, is a long-standing problem in astrophysics, despite as a "standard candle" for deriving the cosmological distance. We propose ALMA CO observations of the Type Ia supernova remnant 3C 397, in order to reveal its progenitor system. Most recently, we have revealed an expanding bubble toward 3C 397 using archival CO data obtained by a single-dish telescope, indicating the single degenerate origin. However, we could not establish the cloud association due to modest angular resolution (~20 arcsec), sensitivity, and lack of high-excitation lines of CO. The proposed ALMA ACA observations of CO(J = 2-1) and SiO(J = 5-4) at resolutions of ~6 arcsec (~0.3 pc at the distance of 3C 397) will verify the cloud/wind-bubble association with the Type Ia SNR 3C 397, and solve the problem of its progenitor system. ALMA is the only telescope array that can address the long-standing problem. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-07-11T03:56:43.000 |
| 2079 | 2017.A.00045.T | 215 | The origin of the non-thermal emission of the peculiar transient AT2018cow | The ATLAS survey has identified the peculiar transient AT2018cow, in a disturbed spiral galaxy at 60 Mpc. This transient has a multi-component broadband spectrum: It shows a very blue continuum, indicative of a very hot thermal component, a significant emission in X-ray and millimetre wavelengths, pointing towards a relativistic event, and an emerging broad-lined type Ic supernova component, typical of gamma-ray bursts. All this together make AT2018cow a unique event that may be originated from an unknown type of stellar explosion. We propose to use ALMA, in coordination with other ground-based and space observatories to study the broadband evolution of this first-of-its-type event. | Gamma Ray Bursts (GRB) | Cosmology | 2019-01-07T03:28:27.000 |
| 2080 | 2019.1.01514.S | 912 | Confirming large-scale structures of dusty galaxies around enormous Lyman-alpha nebulae and high-z quasars | Recently, rare enormous Lyman-alpha nebulae (ELANe) have been discovered around high-z quasars. ELANe are associated with multiple AGN and overdensities of Lyman-alpha emitters, implying they sit in very rich structures. To better constrain the environment of the 4 best known z~2-3 ELANe, we targeted these fields with SCUBA-2/JCMT, together with a control sample of 5 z~3 quasar fields. The exciting results show high number counts in all the 9 fields whit respect to blank fields at 850 micron, suggesting that even quasars reside in dense structures once probed at sub-mm wavelengths. To confirm/disproof the association of both ELANe and high-z quasars with dense environments, we thus propose to exploit the sensitiveness and frequency coverage of ALMA to target - with a fast-survey approach - all the 108 highest-fidelity sources detected with SCUBA-2. Our aim is to confirm their redshift association by targeting the CO(4-3) line (band 3 or band 4) and to get a precise position identification from their bright continuum in band 7. This dataset will also provide a first molecular and dust mass estimate, allowing us to study any trend within the discovered large-scale structures. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2021-04-15T12:07:48.000 |
| 2081 | 2012.1.00761.S | 3 | Unveiling Planet Formation Disk around Class III T Tauri Star Sz 91 in Lupus III | We propose high spatial resolution imaging of class III T Tauri star, Sz 91, in Lupus III (d=200 pc) in CO(3-2) and continuum emission with the extended configuration. Sz 91 is the most peculiar transition disk ever discovered, where planets are more likely to be currently forming. One of the spectacular features appears in its SED, where the large dip and sharp rising at mid-infrared, and it suggests the large inner hole of the disk with the sharp inner edge. Our recent SMA 345 GHz and CO(3-2) images at ~1 arcsec resolution successfully revealed a 200 AU scale disk in gas and dust together with the possible inner hole. This type of disks seems to be extremely rare among young population, 1-2 % or less. Furthermore, very recently an H-band scattered disk with a gap at R~40 AU has been discovered with Subaru/HiCIAO. These make it to be one of the most suitable targets to unveil planet forming regions with ALMA. Our proposal aims at (1) The first sensitive and high spatial resolution imaging of planet forming disk. Taking into account that the disk mass is estimated to be ~10^{-3} solar mass which is lightest among transition disks ever detected and the declination of Sz 91 is ~39 degree, only ALMA allows us the imaging in dust and gas at 0.2 arcsec resolution for the very rare and precious example. The resolution is needed to resolve the inner hole with direct imaging at 345 GHz. (2) Revealing the origin of inner hole with imaging of gas and dust. The same inner hole in gas as in dust is expected only for the photoevaporation. This, however, seems to be not the case for Sz 91, and dust growth or planet formation seems to be taking place and predicts the inner hole only in dust. With higher resolution and sensitivity of ALMA, we will confirm the gap formation mechanism based on the predicted distribution of gas as well as dust. The imaging of gas also provides the fundamental kinematical signatures of the disk such as a rotation law, the direction of the disk major axis etc.. | Disks around low-mass stars | Disks and planet formation | 2016-12-07T05:35:36.000 |
| 2082 | 2022.1.01625.S | 17 | Monitoring Giant Planet High-Altitude Jet Streams | The upper atmospheres of Jupiter and Saturn display remarkable variability from jet streams that evolve over non-seasonal timescales and influence their surrounding environments. Data acquired over multiple decades have revealed patterns in stratospheric temperatures that can be explained as the interaction of waves produced from convection and their impact on the changes in speeds of equatorial winds. Inspired from a terrestrial analogue, theories and models have been developed to better understand how each phenomenon compares to its counterparts in other planets, and how they can each be perturbed by large-scale weather events also. The initial step in understanding outlier data in any system is to first characterize its properties, recognizing trends and measuring its natural variability over appropriate timescales to properly contextualize anomalous behavior. We propose an ambitious observational campaign utilizing the ACA to create a record of stratospheric wind measurements for Jupiter and Saturn to investigate the dynamical impacts of processes and events operating different timescales. | Solar system - Planetary atmospheres | Solar system | 2024-05-16T22:27:19.000 |
| 2083 | 2011.0.00469.S | 0 | The cold debris disk in the unique planetary system around HR 8799 | HR 8799 is the only multi-planet system with direct imaging available, and its debris disk is a prime ALMA target to understand how planetary systems form and evolve. We propose to observe continuum emission of the cold planetesimal disk of HR 8799 at 345 GHz (Band 7) in order to (1) determine the disk structure probing for signatures of resonant structures, asymmetries and spiral structure; (2) constrain the unknown disk inclination; and (3) determine accurately the inner disk edge. We should be able to detect the various expected features, and compare the observed structure with predictions of models. Additionally, the observations will provide a first epoch for the exploration of orbital motions of the observed structures. | Debris disks | Disks and planet formation | 2014-03-12T21:22:00.000 |
| 2084 | 2013.1.00537.S | 8 | Exploring the chemical fingerprint of episodic accretion | We propose to test the episodic accretion model for low mass star formation using the chemical memory engraved in the envelope of low luminosity protostars. For this test, we will observe four low luminosity sources (IRAM04191, CB68, CB130-1, and L673-7), including two VeLLOs (IRAM014191 and L673-7), in C18O 2-1, HCO+ 4-3, and DCO+ 5-4 with the ALMA configuration of C34-1. With these data we will explore structure in chemical abundances between the inner and outer regions of the envelope. Chemical abundances are strongly sensitive to local physical conditions. Thus during a burst the chemical signature will change and this signature will persist even when the system enters the quiescent stage. With knowledge of the physical structure we will be able to extract key information regarding the presence and uncertain timescales of episodic accretion. | Intermediate-mass star formation, Astrochemistry | ISM and star formation | 2016-06-15T10:46:01.000 |
| 2085 | 2019.2.00227.S | 90 | Starbursting GMCs in Nearby (Ultra-)Luminous Infrared Galaxies | (U)LIRGs form stars 10-100 times more efficiently than main sequence galaxies, which is attributed to nearby (U)LIRGs being gas-rich merging galaxies. Numerical simulations and sub-kpc observations clearly show that tidal interaction between gas-rich progenitors is condensing gas and triggering subsequent starburst activity in the nuclear region and throughout the extended disk. However, it is unclear if the properties of GMCs -- the sites for star formation -- in (U)LIRGs differ as well from those in main sequence galaxies potentially implying important changes to current theories. Before ALMA it was impossible to study GMCs in (U)LIRGs. The ~60 pc resolution CO(2-1) data for 12 nearby (U)LIRGs in the ALMA archive miss ~30-50% of the total flux arising from shorter spacing. This missed flux severely biases any measurement of GMC properties and CO-to-H2 conversion factor by factors of 1.5-5. To remedy this situation, we request ACA for 12 U/LIRGs to assemble a homogeneous 17 sample suitable to study GMC properties in extreme star-forming environment. The proposed observations will give us an unprecedented, statistically significant number of more than 3,000 GMCs in U/LIRGs. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG), Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2021-04-08T12:33:57.000 |
| 2086 | 2023.1.01441.S | 0 | Do they exist? - Pushing the limits for low-mass dark matter halos searches | We propose to observe four strongly lensed dusty, star forming galaxies (DSFGs) in band 7 with the aim of detecting low mass dark matter halos, or confirm they do not exist, by measuring the perturbations they can potentially cause in lensed images of background sources. We have determined that the datasets from the proposed observations will be sensitive enough to the presence of subhalos of mass at least as low 10^9 M_sun, a mass regime that can not be achieved with current ALMA archival datasets other the data for SDP.81 from the science verification observations. This is a fundamental mass regime to probe since predictions from different dark matter models (e.g. Cold vs Warm dark matter) for the abundance of low mass halos begin to deviate below this mass limit. ALMA is in position to potentially challenge, or confirm, the favoured cosmological model of the last few decades. | Gravitational lenses | Cosmology | 2025-01-05T10:57:04.000 |
| 2087 | 2012.1.00979.S | 5 | A pilot survey for [CII]157.7um emission in star-forming galaxies at z=1.7 | We propose to conduct the observations of [CII] line and dust thermal emission from star-forming galaxies at z=1.7. We have already conducted z=1.7 [OII] emitter survey in SXDF with the narrow-band filter on Subaru telescope and identified more than 180 [OII] emitters. By subsequent near infrared spectroscopy, the H-alpha and [NII] spectra are obtained from our [OII] emitter sample. The targets consists of 4 normal star-forming galaxies extracted originally from these [OII] emitter sample with the spectroscopic redshift and high SFR. Our goal is to detect the [CII] emission line from less luminous galaxies at z>1 for the first time. And also, we aim to measure the dust obscured star formation rate by the dust continuum observation. By combining the dust obscured star formation rate with the UV-based dust un-obscured one, we can obtain the total star formation rate. These expensive data-set are very suitable for comparing SFRs between some independent indicators. Proposed observation provides us the precious information for [CII] studies of galaxies at highest redshift (z=3-8). | Starburst galaxies | Active galaxies | 2016-08-13T11:35:54.000 |
| 2088 | 2018.1.01670.S | 489 | Building a sample of [NII] 122 and 205 micron emission lines in high-z dusty star forming galaxies | The South Pole Telescope has detected around 100 bright and lensed dusty star-forming galaxies at high redshift in a 2500 deg^2 survey, with APEX/LABOCA and Herschel/SPIRE followup. We have secure redshifts for a sample of 76 DSFGs (CO and [CII] based) out to z~7. A successful proposal in Cycle 4 allowed us ACA observations of the [NII] 205 micron emission in 42 of our sources for 3 | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2019-12-19T20:02:26.000 |
| 2089 | 2017.1.00474.S | 21 | Multiple star formation of a starless core in the Orion A cloud | Our ALMA observations have focused on a prestellar core (TUKH122) located in the Orion A cloud to reveal the initial conditions of star formation in GMC cores. This core is located in a filament and is suggested to be on the verge of star formation because the turbulence is almost completely dissipated and this core is chemically evolved. Interestingly, we found some condensations within the core by ALMA cycle 3 observations, which may suggest a site of multiple star formation. To understand the differences of multiple and single star forming processes, it is highly needed to reveal the density and velocity structures in these condensations. Therefore, we propose to image 1.3 mm continuum, N2D+ (J=3-2), DCO+ (J=3-2) and 12CO (J=2-1) lines. We will investigate the density profiles toward these condensations and the parent core. Furthermore, velocity fields allow us to investigate fragmentation process and angular momentum of these condensations. These high dynamic range and fidelity data will give us the first robust example of the initial conditions of multiple star systems. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-12-18T00:00:00.000 |
| 2090 | 2018.1.01841.S | 43 | CO line widths of massive, compact galaxies with anomalously small Halpha line widths at z~2 | Five years ago the CANDELS survey identified a large populatio of compact (R_e ~ 1 kpc), massive (M_stars ~ 10^11 Msun) star forming galaxies at z=2-3. These are thought to be the immediate progenitors of quiescent galaxies at z~2, which are equally compact. Subsequent dynamical studies in the Halpha line revealed a puzzling anomaly: even though the expected line widths of these galaxies are sigma ~ 300 km/s, their observed line widths are a factor of 2-3 lower (100 - 150 km/s). Strikingly, with the exception of one object with an Halpha line width of sigma=320 km/s, no compact massive star forming galaxies at z~2 have been dynamically confirmed. It has been suggested that this is because the rapidly rotating gas is obscured by dust. Here we propose to test this hypothesis by obtaining CO kinematics of three of these galaxies. If dust is responsible for the peculiar Halpha kinematics then we should observe CO line widths of sigma ~ 300 km/s. If, on the other hand, we observe CO line widths that are similar to those of Halpha this may imply that the masses of compact star forming galaxies are overestimated by a factor of 10. | Starbursts, star formation, Early-type galaxies | Active galaxies | 2020-01-10T19:14:29.000 |
| 2091 | 2023.1.00691.S | 0 | Are terrestrial planets forming around HD 166191? | Giant collisions are necessary for terrestrial planets to grow to masses bigger than the mass of Mars. Simulations indicate that these giant collisions produce abundant amounts of SiO gas. The detection of SiO gas in a debris disk would be indicative of terrestrial planet forming giant collisionss. SiO, however, has never been detected in a debris disk, likely because of its short gas phase lifetime. The HD 166191 system provides a great opportunity to detect SiO in a debris disk for the first time, as intense collisional activity in its terrestrial planet zone was seen in the past 4 years with Spitzer. The size of the colliding bodies and the scale of the collision remain unknown. We propose observations in band 7 of the HD 166191 system to look for SiO produced in the collision and detect SiO in a debris disk for the first time, as well as constrain the millimeter-sized dust mass that was produced in the collision. This project will determine the scale of the collision seen in this system and thus if it is related to the formation of terrestrial planets. | Debris disks | Disks and planet formation | 2025-06-05T19:50:47.000 |
| 2092 | 2011.0.00223.S | 0 | The rotating equatorial disk in the Red Rectangle | We propose high-resolution (extended configuration) ALMA observation of the Red Rectangle in 12CO and 13CO J=3-2 (simultaneously observed in band 7) and in 12CO J=6-5 (band 9). The Red Rectangle is a well known protoplanetary nebula (PPN) surrounding a binary star that shows spectacular images in the optical and IR. It is the only PPN in which an equatorial disk in rotation has been clearly detected, by means of CO J=2-1 and J=1-0 PdBI maps. Such disks are still poorly observed, although their study is basic to understand the post-AGB evolution and the shaping of planetary nebulae. Both phenomena are thought to be driven by the ejection of very fast and collimated jets during the first post-AGB phases, which are probably due to reaccretion of circumstellar material via a rotating disk (as in young stars). High-resolution ALMA maps of CO emission, including the high-excitation J=6-5 line (a good probe of the temperature in our case), will significantly improve our knowledge of the structure and dynamics of the disk in the Red Rectangle. ALMA data will be combined with recently obtained Herschel/HIFI spectra of CO high-frequency lines. We will study in detail the distributions of density and temperature in the disk, including an accurate investigation of the origin of the evaporation of gas from the disk and a deep search for infalling gas in its inner regions. Because of the favorable conditions to the observation of this source and the expected spectacular results, we think that this project is very well adapted to the ALMA early science program. | Post-AGB stars, Disks around high-mass stars | Stars and stellar evolution | 2013-11-23T08:13:49.000 |
| 2093 | 2019.2.00081.S | 10 | Extended Measurements of the Most Energetic Event in the Universe | Galaxy clusters are the largest gravitationally-bound objects and, according to the hierarchical picture of structure formation, form through mergers and accretion, which violently dissipate their kinetic energy in shocks. The merger in 1E0657-56 -- a.k.a. "the Bullet Cluster" -- is one of the cleanest astrophysical labs for shock physics and may be the single most energetic event in the observable Universe since the Big Bang itself. The Bullet Cluster provides direct evidence that clusters are dominated by cold dark matter through the large spatial separations between the gas and lensing peaks. In 2013.1.00760.S, we observed this cluster using ALMA+ACA Band 3. Our analysis provides results which are competitive with X-ray observations, and indicate that expanding our coverage would provide further astrophysical tests. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2022-11-15T20:25:41.000 |
| 2094 | 2022.1.00554.S | 23 | Determining the primary nitrogen reservoir by ammonia ice deuteration | Nitrogen is one of the third most abundant heavy elements in the ISM. Observationally determining the primary nitrogen reservoir in the ISM is essential to understanding nitrogen chemistry. However, as the direct observations of N and N2 are challenging, the primary nitrogen reservoirs are not yet constrained. Based on the previous astrochemical modeling study, we propose to constrain the primary nitrogen reservoir in the ISM by observing multiply-deuterated ammonia gas in the warm inner regions of protostellar envelopes where ammonia ices have freshly sublimated. The proposed observations will distinguish whether the molecular forms (N2 or NH3) or atomic nitrogen are the primary reservoirs in the ISM. The result will provide fundamental insight into the nitrogen chemistry in the ISM and the interpretation of how nitrogen will be incorporated into planet-forming disks and eventually planetary bodies. | Low-mass star formation, Astrochemistry | ISM and star formation | 2025-09-17T15:12:11.000 |
| 2095 | 2017.1.01252.S | 9 | Exploring the Cosmic Origins of Chiral Molecules | We have recently reported the first detection of a chiral molecule in the interstellar medium, toward Sgr B2(N) (McGuire & Carroll 2016). Chiral molecules represent a critical class of organic species that drive biology. The cosmic origin of these species is proposed to have its origins in cometary and asteroidal material. Our initial detection of propylene oxide was in the cold outer envelope of Sgr B2, however it is not clear how representative this population is of the more evolved hot core chemistry, which seeds planetesimal inventories, and the detection lacks any information on spatial distribution. Here, we propose observations of the strongest propylene oxide transitions toward the hot cores of Sgr B2(N) to map the distribution and excitation of this key molecule in this source, and determine under what conditions it might be incorporated into icy material in pre-solar envrionments. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-01-23T19:50:12.000 |
| 2096 | 2019.2.00039.S | 24 | Mapping Neutral Carbon in the Helix Planetary Nebula | Though best known as optical emission-line sources, certain planetary nebulae (PNe) also contain large masses of molecular gas and dust that surround or (often) even lie embedded within their ionized interiors. The resulting PDRs in PNe thereby serve as relatively geometrically simple analogues to highly complex and/or poorly resolved systems, such as protoplanetary disks and active galactic nuclei. We propose to use the ALMA Compact Array (ACA) to map 492 GHz [C I] emission within the plasma-embedded globules and highly extended molecular envelope of the Helix Nebula. We seek to investigate and characterize gradients in the abundance of atomic carbon relative to CO across a range of PDR conditions in a system with well-understood geometry. Our primary goals are (1) to trace UV-driven photodissociation and chemistry of nebular molecular gas, and (2) to constrain the total carbon mass in this PN. Combined with our previous IRAM, APEX, and ALMA molecular line surveys of the Helix Nebula, the targeted 492 GHz [C I] line mapping proposed here will provide us with the most complete picture yet of the impact of UV irradiation on the physics and chemistry of this iconic object. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2022-11-10T18:40:47.000 |
| 2097 | 2022.1.01002.S | 80 | Molecular budget of AGN discs and outflows | We propose to map with ACA 7m array the CO emission in a sample of local AGN host galaxies in order to obtain a reliable overview of the molecular gas distribution and kinematics on kpc-scales. The sample is drawn from a parent sample of 60 hard X-ray selected local AGN from the INTEGRAL IBIS AGN catalog. The 8 selected targets have ALMA 12m array data probing low J CO in the central few kpc, and MUSE/SINFONI@VLT data probing the ionised and warm molecular phase in their discs and NLR. With this proposal we aim at investigating specifically the cold molecular gas distribution over the kpc-scales that were filtered-out by the 12m array. We aim at a) deriving the total mass in the discs and outflows, and assess the cold gas kinematics out to 10-15 kpc scales, a region comparable to the MUSE field of view; and (b) deriving the spatial distribution of the gas fraction, joining ACA and ALMA 12m CO data and the stellar mass distribution derived from optical and NIR imaging. This we will allow us to obtain a comprehensive overview of the cold gas phase, its distribution and kinematics, to probe the AGN-galaxy interaction and scaling relations over different physical scales. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-04-20T17:45:20.000 |
| 2098 | 2016.1.01399.S | 41 | Locating ammonia in TW Hya's disk via NH2D | Using Herschel/HIFI gas-phase ammonia, NH3, was recently, for the first time, detected in a planet-forming disk, around TW Hya. Ammonia is expected to be a major carrier of nitrogen in disks. The amount of gas-phase NH3 and the corresponding NH3/H2O ratio is degenerate with the location of the emitting molecules within the disk, which these single dish observations of this face on disk cannot constrain. We propose to locate ammonia in the TW Hya disk via detection of its deuterated form, NH2D. We expect that NH2D is a good tracer of ammonia in this disk known to be rich in deuterated species. Our Band 8 observations target the strongest predicted line of NH2D and will confirm or reject our hypothesis that ammonia is spatially co-located with the millimeter-sized grains at radii <60 au. If confirmed, this indicates that ammonia likely derives from an ice reservoir; if not, this indicates that gas-phase formation of ammonia dominates. | Disks around low-mass stars | Disks and planet formation | 2019-08-02T10:33:42.000 |
| 2099 | 2018.1.00370.S | 42 | Physical Properties of the Closest Superluminous Supernova Host Galaxy | Superluminous supernovae (SLSNe) are a new class of SNe, which are ~10-100 times brighter than ordinary Ia and core-collapse SNe. The physical nature of the progenitor is still a matter of debate, and it is important to understand the environment of SLSN. Molecular line observations provide physical properties of ISM, however, no observations have been made so far. We propose to observe the CO(1-0) and CO(3-2) lines and dust continuum in the host galaxy of SLSN~2017egm, the closest SLSN to date (z=0.03). The smallest distance, highest apparent brightness among SLSN hosts, and (super-)solar metallicity make the galaxy the best target for studying the environment of SLSN in great detail by using the CO line. Our spatially-resolving (500 pc) multiple CO line observations provide the physical properties such as molecular gas mass, density, excitation condition, and velocity field. Obscured star formation is examined from dust continuum observations. The derived quantities are compared to those of local spiral galaxies, starbursts, and star-forming regions in the Milky Way, allowing us to investigate the properties characteristic of SLSN environment. | Starbursts, star formation | Active galaxies | 2024-10-25T07:46:32.000 |
| 2100 | 2016.1.00639.S | 21 | Physical Properties of Galaxies that Ionize the Universe | Measuring the properties of low-luminosity galaxies near redshift 6 is central to understanding the reionization of the universe. Although hundreds of bright galaxies have now been identified at this era, their number density is too low to even maintain the ionization of the intergalactic gas, and lower luminosity galaxies detectable only via their line emission provide the closest relation between any post-reionization galaxy population and the objects that actually reionized the universe. Prior to ALMA, however, our knowledge of these important galaxies was limited to number counts and luminosity functions of hydrogen Lyman-alpha emission. The luminosity and line profile of this resonance line depend sensitively on the gas kinematics and dust content of the host galaxy, so Lyman-alpha observations alone provide little physical information about the galaxy properties. To establish the typical star formation rate, dynamical mass, and systemic velocity for the lowest luminosity galaxies yet detected at this important era, we request ALMA observations of their [CII] 158 um fine structure emission. | Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies | Galaxy evolution | 2019-04-16T00:00:00.000 |
| 2101 | 2019.1.00663.S | 63 | Molecular outflows in luminous gravitationally lensed galaxies at z=2-5 | Outflows are crucially important for the gas budget and evolution of luminous star forming galaxies and AGNs, with observed mass outflow rates of the same order as the star formation rate. At the peak of the star formation/AGN era at z=2-4, such outflows must play a major role, but become extremely difficult to observe in CO lines. In Cycle 3, we have carried out a very successful pilot project to test OH+ as a tracer of high-z outflows. OH+ is a sensitive outflow tracer in local IR-luminous galaxies, and lies close to CO(9-8) so that both lines are observed in one ALMA tuning. The OH+ line is detected in absorption, blueshifted with respect to the CO(8) which measures the bulk of the star forming gas. The outflow velocity can be measured pixel-by-pixel giving a detailed map of the outflow velocity field and column density. We now aim to expand our sample to 12 outflows, allowing determinations of outflow geometry, velocity field, relation to the underlying IR continuum distribution, mass outflow rates, and constraining driving mechanisms and relations with host galaxy properties, providing a decisive step forwards in our understanding of these flows. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2021-01-25T09:56:56.000 |
| 2102 | 2013.1.00331.S | 7 | The structure and dynamics of the very inner equatorial regions of bipolar planetary nebulae | The shaping mechanism of bipolar planetary nebulae (PNe) has not been fully understood yet. It is clear that the main role in shaping the nebula takes place at its innermost region, where an equatorial density enhancement should be related to the collimation of light and jet-launching from the central star. Appropriately sampling these equatorial condensations at the core of PNe would help determine the shaping mechanism. We request ALMA simultaneous band 7 observations (12CO, 13CO J=3-2 and continuum) of the innermost equatorial regions of 3 extreme bipolar nebulae with rich, tight and structured equatorial condensations. They are excellent candidates for ALMA's current capabilities in a reasonable amount of time: Mz 3, Hen 3-401 and NGC 6302. Our main aim is to use high spatial resolution to detect and map these structures, in order to derive accurate ages and sizes to compare with those of their outflows and determine their role in the shaping of the nebulae. Alternatively, should orbiting disks be found as predicted by models, this would be the first direct detection and mapping of stable disks around planetary nebulae showing well-developed, high-velocity bipolar outflows. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2016-12-08T16:05:47.000 |
| 2103 | 2023.1.00252.S | 0 | Filling in the gap - complex organic molecules in warm transition disks | The composition of planets and comets is set by that of the parent disk; therefore, the availability of complex organic molecules (COMs) in disks is key to constrain as they are the potential precursors of biomolecules. ALMA observations have revealed a rich reservoir of CH3OH, CH3OCH3 and CH3OCHO in two Herbig transition disks. In IRS48 and HD10054, the sublimation of ices at the irradiated dust cavity edge provides a unique opportunity to study the full volatile content of disks. Because these disks are too warm to form CH3OH in situ, the inheritance of interstellar ices is required. Analysis shows that the abundances of CH3OCHO and CH3OCH3 relative to CH3OH are not consistent with those measured for protostars and they also differ between the two disks. This may indicate the energetic processing of the COMs in disks, but with a sample size of two, it is unclear how common this is. We propose a survey of six Herbig transition disks around targeting multiple lines of the COMs detected in disks so far: CH3OH, CH3CN, CH3OCHO, CH3OCH3, tHCOOH. These data will show if the results for IRS48 and HD100546 apply to a larger sample and allow for comparisons to protostars and comets. | Astrochemistry | ISM and star formation | 2025-06-19T22:53:20.000 |
| 2104 | 2024.1.00657.S | 0 | The first deep ALMA and VLA survey of high-mass X-ray binaries | Winds of massive stars are a key influence on a wide range of astrophysical systems, including binary systems hosting a massive star and a pulsar, that may eventually form a merging double compact object binary. We propose the first deep joint ALMA + VLA campaign of such systems, called high-mass X-ray binaries (HMXBs). We request 19 hours of ALMA time (Bands 1, 4, 7) and 6 hours of VLA time (C and X band) to characterise the low-frequency SEDs of six HMXBs. Recent breakthroughs from pilot studies have revealed that sub-mm and radio emission of these targets will be easily detectable with ALMA. With our proposed observations, we will obtain the first unbiased measurements of the mass loss rates of the massive stars in the HMXBs. We will systematically compare these stellar wind properties between transiently and persistently accreting HMXBs, testing the popular but unproven hypothesis that stellar wind differences underlie their different accretion processes. This ALMA + VLA study will therefore open an unexplored avenue to understand mass transfer, mass loss, and binary evolution in HMXBs. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2025-10-16T12:24:14.000 |
| 2105 | 2017.1.01276.S | 1356 | Unveiling the nature of the most HST-dark galaxies at z > 4 | Our current understanding on the cosmic star formation history at z > 4 is mostly based on studies of UV-selected samples. To explore whether we are missing a significant population of massive, UV-faint galaxies, we have identified a significant population of massive galaxies that are very bright at IRAC yet undetected in even the deepest HST/WFC3 H-band imaging, i.e., H-dropouts. Both photometric redshifts and stacked far-infrared SED indicate that most of them are z>4 massive galaxies. This is further confirmed by our Cycle-3 870 um survey of a complete sample of 64 H-dropouts down to [4.5] < 24, yielding a 70% detection rate (median flux of 1.6 mJy). These galaxies are extremely compact (~0.2"), qualifying them as the most promising progenitors of z=2-3 compact quiescent galaxies. To unambiguously determine their nature, we propose a spectral scan towards a subsample of H-dropouts with the reddest 870um/450um colors to confirm their redshifts. These galaxies represent the best sample of massive galaxy candidates at z>4, and will provide profound implications on the number density and star formation properties of the most massive galaxies in the first 1.5 Gyr of the universe. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-04-21T02:27:47.000 |
| 2106 | 2016.2.00190.S | 2 | Identification of Warm Carbon-chain Chemistry in the Isolated Hot Corino Source B335 | Recently, we have conducted the molecular line observations of the isolated protostellar core B335 with ALMA in order to characterize its chemical composition. Various complex organic molecules have been detected, whose distributions are concentrated in the very small region (r~10 au) around the protostar. This result clearly indicates that B335 harbors 'hot corino'. At the same time, we have recognized the moderately bright carbon-chain emission (CCH) extended oveer a few 100 au scale. This is a characteristic signature of warm carbon-chain chemistry (WCCC). Hence, B335 is a hot corino source in the vicinity of the protostar with the WCCC feature in the larger scale. This may be a 'standard' chemical structure of isolated protostellar cores. However, our ALMA observation of B335 lacks short baseline data, which hampers us detailed characterization of the WCCC effect in the outer envelope. Here, we propose the ACA observation with the same frequency setting as the 12 m data already in hand. By combining the ACA and 12 m data, we will delineate the complete chemical feature of B335. The reesult will benefit both astrochemistry and star-formation communities. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-08-21T17:10:12.000 |
| 2107 | 2018.1.00576.S | 590 | ALMA survey of coronal magnetic activity of supermassive black holes in nearby Seyfert galaxies | AGNs host hot plasma, namely coronae, emitting intense X-ray photons. Like the Sun, these coronae are believed to be heated by their magnetic activity. However, coronal magnetic activity in AGNs have never been measured. Utilizing ALMA Cycle-4 observations (#2016:1:01140:S), we have successfully detected coronal radio synchrotron emission from a nearby Seyfert galaxy IC 4329A. This discovery has been first achieved by ALMA's high angular resolutions and sensitivity at the millimeter bands. The inferred magnetic field strength is of ~10 Gauss on scales of ~40 Schwarzschild radii from the black hole, which are key parameters for understanding of corona heating and jet launching. Here, we request ALMA Band-3, 4, and 6 observations toward nine Seyferts in order to establish the ubiquitousness of coronal magnetic activity in Seyferts. By establishing the existence of coronal synchrotron emission with this survey, ALMA will open a new observational window for the study of AGN accretion physics. We also request two epoch observations toward each target at the Band 3 to see the time variability. Variability measurements will enable us to constrain the size of the emitting region. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2019-11-05T18:39:39.000 |
| 2108 | 2013.1.00553.S | 26 | Molecular oxygen in Orion | The gas-phase abundance of O2 in cold, well-shielded clouds has been determined by SWAS, Odin, and Herschel to be 2 to 3 orders of magnitude lower than predicted. Explaining this discrepancy is a very strong test of chemical models and our understanding of interstellar chemistry. Herschel has had a major impact, but has not resolved the controversy. One of its limitations has been its relatively large beam size that dilutes the signal from sources of small angular size, and prevents identification of the emitting source and its size in the complex case of Orion OMC1. Unlike the common isotopologue, 18O16O can be observed from the ground. The 234 GHz line is the best candidate and should be detectable with ALMA, and ALMA only. With a synthesized beam size of a few arcsec, we will be able to pinpoint the location of the source of the oxygen emission and its characteristics, and find the explanation for the general absence but selective enhancement of O2 in interstellar clouds. An additional product of this study will be a deep survey in 14 GHz of band 6, with a sensitivity never achieved in standard surveys. This will help clarify why O2 behaves so differently than expected | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-09-25T00:00:00.000 |
| 2109 | 2019.1.01457.S | 71 | CO excitation and star-formation in gas-selected galaxies from z=0.5 to z=2.6 | Damped Lyman alpha galaxies trace the dominant reservoirs of neutral hydrogen gas throughout cosmic history. Studies from UV, optical and near-IR emission have revealed rather low levels of star-formation activity at the respective redshifts. Surprisingly, targeting DLA systems with ALMA, we have found that a high fraction of the DLA-selected galaxies also have significant amounts of molecular gas similar to their stellar masses. Current understanding of the role of these absorption selected galaxies in the context of galaxy evolution is severely limited, and we need to determine the physical nature of the molecular gas, and its connection to the star-formation activity in these systems. In order to constrain the state of the molecular gas we here propose to target 6 DLA galaxies with high CO luminosities. With the proposed observatons, we will measure CO in a range of spectral-line transitions from CO(J=2-1) through to CO(J=7-6), with which we will determine the excitation state, density and temperature of the gas. Individual CO lines and their ratios are needed to measure hidden star-formation, and star-formation surface densities. | Damped Lyman Alpha (DLA) systems | Cosmology | 2021-03-30T22:54:26.000 |
| 2110 | 2021.1.01438.S | 152 | Unveiling the early phases in the evolution of compact and massive galaxies at the cosmic noon | Using the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan survey an unique and puzzling sample of star-forming galaxies with extremely large luminosities in the UV and Lya (up to MUV=-24.6, log(Lya,erg/s)=44.0) has been recently discovered. From deep rest-frame UV and optical spectra and SED, these sources appear to be dominated by very intense bursts of star-formation (up to 700 Msun/yr) with very young (<10Myr), compact (~1kpc) and almost un-obscured (UV slopes of -1.7 to -2.5) stellar populations, without any evidence so far for AGN activity. We request ALMA observations for eight of the most luminous and vigorous star-forming galaxies in our sample to 1) constrain the presence of dust emission and the mechanisms of dust formation in the early phases of vigorous starbursts, and 2) probe the molecular gas mass and depletion times. These galaxies might represent an early phase in the evolution of massive galaxies, such as quiescent galaxies and/or (sub)millimeter selected galaxies detected at high redshift. They could represent a new class of extremely UV and Lya bright star-forming galaxies in the distant Universe that have been missed in previous surveys. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2022-12-09T16:40:20.000 |
| 2111 | 2016.1.00692.S | 10 | ALMA-GAIA Reference Frame Link | The Gaia spacecraft has started its five year mission to measure the sub-mas positions of over one billion stellar objects. The linking of the future Gaia celestial reference frame (GCRF) to that of the current IAU-sanctioned International Celestial Reference System (ICRS) is critical across all wavebands for many astronomical and terrestrial measurements, for space navigation and for tests of fundamental physical quantities. To align its coordinate frame with that of the radio ICRS, the Gaia star positions must be compared with counterpart radio objects. The two major comparison sets of objects are: (1) quasars with accurate sub-mas VLBI positions but nearly all are identified with faint objects; and (2) bright, single stars that have significant thermal emission at mm and sub-mm wavelengths. This proposal will select about 24 stars that are single and easily detected by ALMA with a 10-min integration in order to measure their positions with 0.5 mas accuracy at 350 GHz to compare with that of Gaia. This will be one of the methods of linking the Gaia reference to the ICRS reference frame. | Main sequence stars | Stars and stellar evolution | 2018-01-24T16:20:53.000 |
| 2112 | 2017.1.01347.S | 186 | Science with ALMA and JWST: Tracing the Heating and Cooling in Star Forming Regions in Galaxies at Cosmic Noon | We propose [CII] observations of a unique sample of galaxies at cosmic noon with existing mid-IR spectra that show much more luminous polycyclic aromatic hydrocarbon (PAH) emission than local infrared luminous galaxies. The trend of LPAH/LIR with LIR is reminiscence of the [CII]/LIR vs LIR relation, suggesting that both the PAH and [CII] emission are dominated by photodissociation regions in high redshift dusty galaxies. With this proposal we aim to confirm this relationship at high redshift, and further understand how the star formation may be different during the peak epoch. With the impending launch of JWST, our access to the powerful mid-infrared diagnosics of the interstellar medium, namely the bright PAH features, will be renewed. This project will be important in establishing the power of combining measurements from JWST and ALMA to understand the conditions for star formation during the peak epoch. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-08-13T22:50:31.000 |
| 2113 | 2018.1.01410.T | 145 | A Precision Test of Gamma-ray Burst Afterglow Models | GRBs are powered by extreme compact objects (black holes or magnetars) that eject matter at ultra-relativistic velocities (Lorentz factor >>100). This makes them ideal laboratories to study radiation processes in extreme conditions. The fast-reacting GRB satellite Swift has been in orbit for more than 13 years, but only in the last few years have radio and submillimeter facilities obtained sufficient sensitivity and response time to test afterglow models in detail. Those tests are fundamental and address key difficulties in understanding the physics of cosmic particle-accelerators. We propose a joint ALMA+JCMT+NOEMA+GMRT effort to study one GRB afterglow this cycle from early (hours) to late times (months) across the radio spectrum. With ALMA, we propose to secure 5 epochs at 95 and 340 GHz separated by 8-20 days in each band. We will complement these observations with X-ray and optical data to model the broadband afterglow in detail, allowing us to precisely test models and characterise non-standard radiation components. | Gamma Ray Bursts (GRB) | Cosmology | 2021-01-09T00:11:16.000 |
| 2114 | 2018.1.00293.S | 27 | The Dragonfly Galaxy: resolving feedback and star formation in a hyper-luminous AGN merger at z~2 | The Dragonfly Galaxy is one of the most IR-luminous radio galaxies in the high-z Universe. With one nucleus hosting a radio-loud AGN and the other dominated by a starburst, this system has all the properties to study different aspects in the evolution of massive galaxies. We performed both ALMA Cycle-2 and Cyle-4 programs of CO(6-5) and dust continuum, complemented with ambitious VLA observations of the jets. This revealed that molecular gas is re-distributed at a rate of >1000 Msun/yr, possibly through massive gas outflows from the merging nuclei, and that the radio jet interacts with the gas in one of the nuclear discs. With these ALMA Cycle-6 observations, we will zoom in at the gas in the central disks with a resolution approaching that of giant molecular clouds (~250 pc). This will allow us to trace the gas and dust across an unprecedented three orders of magnitude (from the CGM to the nucleus), to understand the symbiotic relation between the growth of the black hole and host galaxy. Imaging gas and dust in a z=2 merger on scales comparable with studies of local mergers like Arp 220 will grasp ALMA's promise of understanding galaxy evolution in the Early Universe. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2020-11-20T22:30:50.000 |
| 2115 | 2018.1.00581.S | 44 | Finally resolving the molecular "torus" of the closest Sy 2 AGN: the Circinus galaxy | A toroidal distribution of molecular gas and dust is a key component in the classical picture of active galactic nuclei (AGN). This so-called "molecular torus" is held responsible for the orientation dependent obscuration of the central engine, and it plays a fundamental role for the accretion onto the supermassive black hole. Despite its importance, its physical properties have become even less clear in the last years with the discovery of polar elongated dust structures and the contradicting first ALMA results for NGC1068. Here we propose to finally resolve the molecular "torus" in the Circinus galaxy, the closest Seyfert galaxy and thus the ideal target to study the continuum and molecular emission of the central, AGN dominated source. With the highest possible angular resolution down to ~22mas (0.4pc), we will directly map the molecular gas on scales similar to the already established parsec-scale dust structures. We target HCO+ and HCN (J=4-3 and 3-2) in order to trace the morphology, kinematics and temperature stratification of the dense material around this AGN. We especially aim to distinguish if the structures are dominated by inflowing, rotating or ouflowing motions. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2022-10-28T17:03:48.000 |
| 2116 | 2022.1.01040.S | 0 | Precision measurement of the black hole masses in the radio galaxies NGC 315 and NGC 4261 | NGC 315 and NGC 4261 are two of the nearest and best-studied FRI radio galaxies. Cycle 5 CO(2-1) observations of the circumnuclear disks at 0.30" resolution reveal high-velocity emission with spectacular rises in rotation speeds within each galaxy's innermost 100 pc. The central emission, extending to line-of-sight speeds of ~500-600 km/s, originates from deep within the gravitational sphere of influence of the central supermassive black hole (BH). NGC 315 and NGC 4261 are two of only a few early-type galaxies in which a central Keplerian rise in rotation speed has been firmly detected with ALMA, making them some of the best targets yet identified for high-precision BH mass measurement. Recent gas-dynamical modeling gives M_BH ~ 2.1x10^9 Msun for NGC 315 and 1.7x10^9 Msun for NGC 4261 (Boizelle et al. 2021). We propose to observe NGC 315 at 0.1" resolution and NGC 4261 at 0.15" resolution in order to highly resolve the gas rotation within the BHs' spheres of influence, which will enable us to carry out high-precision measurements of their central masses. The result will provide new benchmarks for testing BH mass measurement methods and for modeling the BH accretion flow and jet. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2025-02-10T00:52:17.000 |
| 2117 | 2015.1.01229.S | 17 | Exploring the Early Stages of Formation of Disks and Outflows in Uneven Close Binary Systems. The Case of SVS 13 | The formation of accretion disks in close (separation < 100 AU) binary systems, and particularly in those where both components show different properties, is poorly understood. Theoretical models have shown that depending on the mass ratio of the components and the specific angular momentum of the system, a circumstellar disk can be formed around one or both of the components. Under some high angular momentum conditions even a circumbinary disk can be formed. However, very few candidates of young close binary systems have been resolved. A remarkable example is SVS 13, a binary system with a projected separation of 65 AU that has been resolved by the VLA. The observations suggest that one of the components is associated with a circumstellar disk, while the companion is an optically visible star with marginal or absent dust emission. We propose ALMA band 7 line and continuum observations that will allow us to test the role of the different ingredients in the formation of a star-disk-jet system in the presence of a close companion. This scenario is probably more common than the isolated case. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-12-02T21:08:38.000 |
| 2118 | 2022.1.00999.S | 10 | Revolutionary insights into the z>7 gas and dust physics | Although high-z galaxy sample sizes with FIR line and dust continuum detections have known a boost with ALMA, the characterisation of their gas and dust reservoirs remains elusive. We propose to target five FIR lines ([OIII]52,[NII]122,[OI]145,[CI]370,CO7-6) and the underlying dust continuum in the brightest [CII]-, [OIII]88- and dust-detected z=7.306 galaxy (UVISTA-Y-003). This ambitious program will allow us to unambiguously constrain the gas densities, ionisation parameter, ionising photon escape fraction, molecular gas mass and gas-phase O, C and N abundances. We will gain unprecedented insights into the early metal and dust enrichment, the efficiency of star formation, and the contribution of massive galaxies to cosmic reionisation. The exquisite sampling of the rest-frame 52-370 micron dust SED comes for free, and will enable us - for the first time - to cover the z>7 dust SED peak and to constrain the dust temperature, mass and IR luminosity with high precision. The IR luminosity will be crucial to interpret the IRX-beta diagram; whereas the metal and dust masses will allow us to tie down the dominant dust production sources and the importance of gas accretion and outflows. | Starburst galaxies | Active galaxies | 2024-05-17T10:32:28.000 |
| 2119 | 2021.1.00450.S | 14 | Piercing the Opacity-Limited Envelopes of the Youngest Protostars in Orion | The coordinated ALMA (0.87 mm) and VLA (8 mm) survey of 328 protostars in Orion has revealed three extremely young protostars that are irregular, massive (~1 M_sun), compact (R~100 AU), and optically thick at 0.87 mm. These densities imply free fall timescales of ~100 yrs, but the derived properties imply cooling limited contraction over ~2000 yrs. Recently delivered polarization data are giving insights into the role the magnetic field plays to support these objects against collapse. The measured thermal energy is not sufficient to support the cores over a slower contraction, suggesting that there is additional support from rotational and/or turbulent motions. However, no line data exist yet to evalulate possible support mechanisms from rotation or turbulence. Band 3 observations are requested, where the optical depth will be lower, to map the line widths, spatial distribution of 13CO, C17O, C18O, and CN lines, the continuum of the inner envelopes from ~80 - 100 AU, and measure infall signatures. This will reveal the motions of the inner envelopes for the first time and determine the basic energy balance for support, by directly evaluating the turbulence and/or rotational energy. | Low-mass star formation | ISM and star formation | 2024-06-16T23:03:58.000 |
| 2120 | 2017.1.00358.S | 90 | CO spectral imaging the hosts of the most extremely-luminous AGNs. | A new class of extremely luminous active galaxies, `HotDOGs', were found by mid-IR selection from the WISE all-sky survey. HotDOGs are a population of powerful AGNs with characteristic hot far-IR SEDs, and luminosities reaching over 10^14 Lsun. They have well-defined redshifts, luminosities & SEDs, and are as numerous as comparably-luminous optical QSOs. HotDOGs' luminosity is dominated by very-obscured AGN, unlike either low-z ULIRGs or high-z submm-selected dust-enshrouded galaxies (SMGs/DSFGs). HotDOGs likely offer key tests of feedback/accretion. We propose sensitive Band-3 spectroscopy of the ISM in a complete sample of 10 HotDOGs/host galaxies, to reveal the size, morphology and dynamics of the molecular gas; and thus give the abundance of fuel for their AGNs, and the strength of their outflows. HotDOGs are the MOST extreme galaxies, forming their blackholes and undergoing feedback at the greatest rates: our spectral probe of their brightest CO lines will reveal the processing and consumption of gas in these dramatically luminous galaxies at an epoch when galaxy formation was at its most intense, and perhaps show how this remarkable phase is initiated and terminated. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-01-12T03:07:32.000 |
| 2121 | 2019.1.01382.S | 8 | Sub-kiloparsec mapping of the molecular gas in a quintessential merger-driven starburst at z=1.52 | We aim to map the spatially-resolved molecular gas distribution using the CO 5-4 line and dust continuum of PACS-787, an archetypal twin-galaxy merger at z=1.52 with extreme star formation rates from Herschel and ALMA. We already have CO measurements with ALMA of two transitions: J=2-1 at 2" resolution (giving total gas mass) and J=5-4 at 0.3-0.4" resolution (gas and dust mass on ~1 kpc scales). These show a merger of two massive gas-rich galaxies separated by 8.6 kpc, a high efficiency of forming stars in both nuclei, and the existence of compact (r ~ 1 kpc), likely counter-rotating disks that may funnel gas inflows to the nuclear regions. With a spatial resolution of 0.04", we will map the structure and kinematics of the two galaxies on scales of ~300 pc. A deep map of the two galaxies at such resolution will allow us to accurately model the two disks, derive their dynamical masses, constrain the L_CO to gas mass conversion factor, establish to which extent these starbursts are driven by higher gas content or higher star formation efficiency (SFE) and explore variations (radial or in clumps) of the SFE, thus shedding light on the physics of starbursts at high redshift. | Starburst galaxies | Active galaxies | 2022-06-09T11:59:29.000 |
| 2122 | 2019.1.01303.S | 15 | How to Feed a Torus: Resolving the center of Circinus | AGN tori are fundamentally important components in models of active black holes, however their typical sizes, geometry, and structure are poorly constrained. We propose to conduct 0.02" to 0.2" (0.4-4 pc) Band 3 and Band 7 observations of the central 300 pc of Circinus to make the highest-ever resolution study of an AGN torus and probe its connection to the surrounding gas. These observations will resolve the compact torus and the distribution of surrounding gas on scales from 0.4-300 pc and constrain the kinematics of the gas flow toward one of the nearest AGN (a Type 2 Seyfert at d=4.2 Mpc). We will measure the density of gas in the torus and its larger-scale surroundings and test chemical (e.g. X-ray Dominated Region or XDR) models for gas around an AGN. The lack of star formation in the nucleus of this galaxy will allow us to use these measurements to uniquely isolate and resolve the impact of the AGN on a galaxy's central gas reservoir. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2022-11-24T00:05:36.000 |
| 2123 | 2018.1.01020.S | 39 | Testing for efficient grain growth in the dust trap around Sz 91 | The probably most popular model for giant planet formation is the core accretion scenario. However, this model is facing serious difficulties. One of the most severe challenges for the model certainly is to overcome the radial drift barrier which is supposed to prevent the formation of planetesimals. Particle traps generated by pressure bumps in the disk are one possibility to slow the radial drift and allow planetesimals to form. In recent years we have characterized the transition disk around the young stellar object Sz91. Based on ALMA Band 7 continuum data (of 0.2 arcsec resolution) we found that the mm-sized particles accumulate in a sharp ring radially unresolved. This ring structure might represent a radial particle trap in which planetesimals could form. We here propose to observe this disk in Band 4 and 7 at high resolution to constrain the sharpness of the ring and the particle size distribution. | Disks around low-mass stars | Disks and planet formation | 2020-11-22T18:14:20.000 |
| 2124 | 2023.1.00868.S | 0 | A search for cold, carbon-rich accretion streams in a massive halo at z=2.9 | Cold accretion of gas from the cosmic web sustains star formation and supermassive black hole activity across cosmic time. Theory predicts the gas is funneled into the core of massive halos through narrow and cold streams, but direct observational evidence of them is scarce. In this proposal, we search for extended cold gas via the [CI](1-0) tracer in the environment of RO-1001, a massive protocluster of galaxies at z=2.9. Previous spatially and spectrally resolved observations of the diffuse Lyman Alpha (Lya) emission associated with this protocluster showed tantalizing hints of inflowing motion along three narrow filaments that connect at the center of the system. Encouraged by the recent detection of molecular [CI]-emitting streams in a similar Lya nebula, we expect to find the truly cold counterpart of the Lya filaments, finally witnessing the fuel of star formation being served into a growing halo. | Lyman Alpha Emitters/Blobs (LAE/LAB), Galaxy structure & evolution | Galaxy evolution | 2025-01-05T16:00:10.000 |
| 2125 | 2018.1.01003.S | 70 | The Role of Magnetic Fields within Dense Molecular Filaments in Vela C | Recent large scale maps of magnetic fields in molecular clouds show that many (perhaps most?) are consistent with having a dynamically important magnetic field. How then do dense structures such as filaments and cores manage to form from a globally magnetized cloud? In this proposal we aim to determine how the gas density distribution is affected by magnetic fields within dense filaments in the young, nearby GMC Vela C (d~700pc). Our ALMA Band 6 observations of the two densest filaments in Vela C will be compared with BLAST maps of large and intermediate scale cloud magnetic fields and 19 arcsec resolution APEX polarimetry maps. Our goal is to 1) determine whether the observed orientation of the magnetic field perpendicular to the dense filaments holds on sub-filament scales, and 2) determine both the filament fragmentation on small scales and also whether these filaments are currently forming protoclusters. We also target lines of several intermediate and high density tracing molecules that, where detected, can be used to determine whether gas is being accreted on to the filaments primarily parallel to the magnetic field (as predicted for a cloud with strong magnetic fields). | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2021-01-10T16:40:02.000 |
| 2126 | 2022.1.00160.S | 10 | Resolved CI study of different star forming environment | CI has been favored as an alternative molecular gas tracer due to its simple 3-level fine structure lines. A tight linear relation has been found between global CI and CO 1-0 luminosity, suggesting CI works well as a global gas tracer. However, only a handful of studies have focused on CI variations within galaxies. A recent study of the LIRG IRAS F18293-3413 shows a superlinear relation between CI and CO 1-0 luminosity at 300 pc scale, which can be due to various enviromental factors. To further study this relation, we propose to observe CI 2-1 along with Band 10 continuum at ~200 pc scale for two nearby galaxies (NGC 3267, NGC 660) and a LIRG (NGC 5104), which already have archival CI 1-0 observations. We also propose for complementary CO 1-0 observations for the galaxies that do not have suitable archival CO data. From these observations, we will fully constrain the gas properties and split out the influence of different enviromental factors onthe CI-CO correlation. | Galaxy chemistry, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2024-01-10T20:03:14.000 |
| 2127 | 2013.1.01052.S | 5 | Tracing the Star Formation at z=6.11 with [OIII] | The cosmic star formation near and beyond z~6 was actively taking shape and evolving through the assembly of normal galaxies eventually to merge into the larger more luminous systems. Probing the ISM in some of the earliest star-forming galaxies is ALMA's flagship. We propose to use ALMA to probe a z=6.11 galaxy of low mass and low metallicity using the 88 micron [OIII] which is the most luminous of the FIR fine structure lines in low-metallicity galaxies. The 88 micron [OIII] line follows tightly the star formation rate and has recently been calibrated as a star formation rate tracer in low-metallicity galaxies. Together these properties highlight the [OIII] line as the best probe of the high-z, low metallicity Universe. Additionally, we propose to observe the 158 micron[CII] line to benchmark the use of the [OIII]/[CII] ratio as an important probe of the structure of the ISM in high-z galaxies and to place constraints on the structure in terms of neutral phodissociation/molecular gas and ionized low density gas. | Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies | Galaxy evolution | 2018-03-22T00:00:00.000 |
| 2128 | 2015.1.01247.S | 36 | Molecular Gas in Dusty Quasars: Fuelling the Formation of Massive Galaxies at z~2.5 | We propose to detect 12CO(3-2) in 4 dust-obscured (Av~2.5), high luminosity (Lbol~1e14 L0), high star formation rate (SFR > 500 M0/yr) quasars at z~2.5 that are caught in a transformative, radiative-feedback dominated phase as they are transitioning from massive starburst galaxies to unobscured quasars. These dust obscured quasars are the highest luminosity quasars currently known at the main epoch of galaxy and supermassive black hole assembly. The proposed CO detection experiment will lead to a five-fold increase in the number of z~2-3 intrinsically luminous, ALMA-accessible quasars where molecular gas has been detected, thus paving the way for future high-resolution observations to look for signatures of AGN triggering and feedback in these systems. Previous searches for molecular gas in high redshift quasars have tended to focus on gravitationally lensed, intrinsically lower luminosity systems or quasars at redshifts above 4. Studying the molecular gas in our high luminosity, highly star-forming quasar hosts will therefore enable new insights into the interplay between star formation and black hole accretion at an epoch when both quantities were at their peak. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-03-07T14:49:38.000 |
| 2129 | 2017.1.00700.S | 13 | Fragmentation and binary formation in the AFGL 4176 disk | We propose to use the long-baseline capabilities of ALMA Cycle 5 at 1.2mm to resolve and characterise the structure and fragmentation of the best example to date of a disk around a forming O-type star. Our Cycle 1 observations of the AFGL4176 disk, also taken at 1.2mm, show that it is in near-Keplerian rotation, but our physical resolution was limited to ~1250 AU. We propose to observe the CH3CN 13(K)-12(K) lines, which are well-tested disk/kinematical tracers and temperature probes. In addition, we will observe 1.2mm continuum to trace the disk surface density at a resolution of 0.025" or 100AU, which using simulations we show is sufficient to uncover fragments in the disk. These three properties (the surface density, kinematics and temperature) will allow us to carry out a highly-resolved stability analysis of a disk around an O-type star. Further, we will search for fragments in the disk sufficiently massive to lead to companion formation, providing insight into the origin of massive binary systems. | Disks around high-mass stars | Disks and planet formation | 2019-01-24T00:10:30.000 |
| 2130 | 2015.1.00960.S | 126 | SiO megamasers in AGN accretion disks | We propose to search for 86 GHz SiO megamasers in 12 galaxies known to have 22 GHz H2O megamaser emission, arising from gas in the circumnuclear accretion disk around the central supermassive black hole. We are motivated in part by the recent detection of SiO as a megamaser in the circumnuclear disk of NGC 1068 (Wang et al. 2014), which is known to host a strong 22 GHz water megamaser. If we detect a disk-like profile in SiO emission, we can use the known (from 22 GHz observations) dynamics to associate the SiO masers with specific regions of the circumnuclear disk. Furthermore, a detection of SiO megamasers in a disk system would provide a fantastic target for current millimeter-wave VLBI facilities, opening up opportunities to map the innermost regions (<~0.1 pc) of the circumnuclear disk. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2017-12-17T05:57:49.000 |
| 2131 | 2013.1.01358.S | 9 | Galaxies in (and behind) two massive high-redshift clusters | We propose continuum, CO(4-3), and [CI] observations of 70 galaxies in the two highest redshift members of a mass-selected Sunyaev-Zel'dovich effect cluster sample. By observing the merging z=0.87 cluster ACT-CL J0102-4915 "El Gordo" and the more regular z=1.06 cluster ACT-CL J0546-5345, we will be able to study how total gas content (for which dust mass is a proxy) and molecular gas content vary with galaxy property, environmental density, and dynamical state in the most massive clusters to be assembled at early times. In addition (particularly for "El Gordo," recently the subject of exquisite strong and weak lensing models), we will be able to characterize the properties of "ordinary" dusty background galaxies that have been gravitationally lensed by the clusters. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2016-03-26T20:47:56.000 |
| 2132 | 2021.1.00782.S | 10 | A deep kinematical study of the young planetary system PDS 70 | Although several thousand exoplanets have been detected, many questions regarding their formation process are still open, largely hampered by the lack of observational constraints. PDS 70, with two planets directly imaged within a protoplanetary disk, is the so far only planetary system which has been directly caught during its formation. This system is thus a unique laboratory where the kinematical imprints of directly detected forming planets on their host protoplanetary disk can be observationally probed. With this proposal we aim to study the PDS 70 disk at the 13CO line in Band 7, in order to trace the kinematic disk structure deeper in the disk than ever before. While corresponding long-baseline observations targeting the 13CO isotopologue are already available in the archive, we ask for a completion of these data with short baseline observations, in order to recover the full emission of the disk. The analysis of these data will provide the first multi-line kinematic view of a directly detected protoplanetary system at formation. | Exo-planets | Disks and planet formation | 2024-03-12T00:00:00.000 |
| 2133 | 2019.1.00574.S | 14 | Caught in the act: disruption of a high-mass disk by anisotropic accretion | Disks and outflows play an important role in the formation process of stars of all masses, from low-mass up to the most massive O-type stars. However, the number of clear-cut disks around O-type stars is still very low. We used ALMA to search for disks in six of them, and found 3 candidates to be confirmed with higher resolution. In this proposal we will resolve the disk around G29.96-0.02, a well-known region for which rotating structures were claimed in the past. Our 0.2-arcsec ALMA observations reveal a new and interesting scenario where the disk is not what it was thought to be, and an energetic and collimated outflow plays a dominant role. Due to non-isotropic accretion, the disk plane orientation has changed. This has modified the orientation of the outflow, which is now disrupting the outer parts of the disk. Complex organic molecules, typically found tracing disks in massive stars, appear now to trace the base of the outflow. We find evidence for a possible compact disk (600 au in size) perpendicular to the current outflow axis. With 25-mas resolution (or 120 au) observations, we will search for the real disk in G29.96-0.02 and investigate the disk-outflow interaction. | High-mass star formation | ISM and star formation | 2022-11-16T23:28:14.000 |
| 2134 | 2021.1.00799.S | 62 | Characterizing the Decline of Massive Protostellar Outbursts | The discovery of 3 accretion outbursts in massive protostars over the past 4 years has motivated new hydrodynamic simulations of protostellar accretion. The results suggest that massive stars gain up to 40-60% of their total mass from episodic accretion, with an inverse relation between outburst duration and peak luminosity. All three of the outbursts arose from protostars that power copious hot core line emission, and each event triggered methanol maser flares. Two of the three outbursts (NGC6334I-MM1 and G358.93-0.03-MM1) remain at elevated luminosities after 6 and 2 years, respectively, and tracking their decline is a key observable to constrain future theory. Our primary goal is to continue characterizing the luminosity evolution of these objects by gathering a new epoch of multi-wavelength millimeter continuum and mid-IR images. With ALMA, in addition to comparing the dust continuum light curve with the maser light curve, we will also be able measure whether the thermal line excitation temperatures, physical extent, and velocity structure have altered since the initial peak of the outbursts, which will impact future studies of hot core chemistry. | High-mass star formation | ISM and star formation | 2023-01-12T19:23:12.000 |
| 2135 | 2016.1.01299.S | 17 | Architecture and disk structure in a high-mass protobinary system | High-mass stars exhibit a significantly higher multiplicity frequency than low-mass stars, likely reflecting differences in their formation mechanism. Theoretical work suggests that the high-mass binaries might form via the fragmentation of self-gravitational disks or alternative scenarios such as disk-assisted capture. Intriguingly, in recent VLTI/AMBER near-infrared interferometric observations we detected a close high-mass protobinary with a 57mas (approx. 170AU) separation. Around the individual stars we resolve near-infrared excess emission that is likely associated with hot dust in circumstellar disks. We characterised the system with SMA sub-mm interferometry and identified a suite of outflow- and disk/envelope-tracing lines that we would like to resolve now with ALMA 40mas-resolution imaging. Our aim is to resolve the circumbinary disk/envelope, to study the signatures of binary-disk interaction, and to search for the accretion streamers that feed the circumstellar disks. We will image the outflow-launching region and determine the dynamical mass of the central objects, providing a first glimpse into the evolution of high-mass multiple systems during the accretion phase. | Disks around high-mass stars | Disks and planet formation | 2018-08-02T04:51:26.000 |
| 2136 | 2019.1.01633.S | 12 | Gold Standard of Dynamical Mass Estimates for z>6 Quasar Host Galaxies | The knowledge of dynamical masses of galaxies is indispensable to put galaxies in an evolutionary context. However, deriving accurate dynamical masses requires significantly resolved measurements of a bright spectral line that are typically not accessible at high redshift. This is why other estimators (~v_disp^2 D) are often employed to put first constraints on dynamical masses in unresolved (or barely resolved) observations, but the implied uncertainties are significant. Out of a sample of 27 quasar host galaxies at z>6 in which bright [CII] emission was detected with ALMA at ~0.2-0.3" resolution, we have identified two galaxies that show large disks with apparently smooth rotation. Using a custom-made Markov Chain Monte Carlo fitting method, these two galaxies are prime targets to obtain accurate dynamical masses through the requested 0.09"(500 pc) and 0.06"(300 pc) [CII] imaging, and thus to test the applicability of low-resolution estimators. These measurements can be directly compared to the central black hole masses in these quasars, to assess how or if their black holes are over-massive compared to local scaling relations. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-01-25T15:41:15.000 |
| 2137 | 2022.A.00026.S | 21 | The state of Betelgeuse after the Great Dimming | Betelgeuse's Great Dimming in 2020 almost certainly involved a mass ejection leading to dust formation. This may have partially blocked the light in our direction, but could also have involved intrinsic stellar dimming and the formation of cool surface spots. In 2022, it was recognised that Betelguese had subsequently undergone a change in periodicity. By April this year, it had also reached an historically high optical brightness (~0.0 magn). Thus it may be undergoing an increase in pulsation amplitude generally, possibly pressaging an increase in mass loss rate or a symptom of an internal upheaval. ALMA in its longest baseline configurations can resolve the star and any starspots, as well as the proposed ejected gas and dust. Recognition of the unusual state of Betelgeuse came after the ALMA long-baseline deadline, but there is a need to catch the system in its' current active state. Comparison with pre-dimming band 7 observations will confirm the presence of recently-formed dust and ejected gas, and multi-band mm - sub-mm imaging will probe increasingly deep into the star, relating stellar inhomogeneities such as convection-related local cooling to the recent mass loss. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-02-21T15:07:43.000 |
| 2138 | 2013.1.01020.S | 10 | Gas Dissipation in Protoplanetary Disks at the Final Stage of Disk Evolution | We propose to investigate the final stage of protoplanetary disk evolution with ALMA. Our tagets (PDS~70, RX~J1604.3$-$2130, IRAS~04125$+$2902, and Sz~91) are weak-line T Tauri stars (WTTS) that have so-called {\it transitional disks}. The large cavities ($r>$20 ~AU) in the central disk-region around these four objects have been imaged at both (sub-)mm and near-infrared (NIR) wavelengths, and this imagery suggests the large-mm-size and small-sub-$\mu$m-size dust grains are dissipated inside the cavity. Among the many transitional disks that have been discovered around classical T Tauri stars (CTTS), these four WTTS systems are likely to be more evolved and close to the epoch of their final stage of disk evolution. We propose to use Band~6 observations at a maximum spatial resolution of 0.$''$18 to measure the amount of gas inside the cavity, in order to obtain observational evidence of gas-decreasing in transitional disks around WTTS. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2016-11-12T17:48:24.000 |
| 2139 | 2013.1.00183.S | 0 | The Pre-Stellar Core Mass Function with Deuterium Chemistry in an Infrared Dark Cloud | Similarities between the shapes of the core mass function (CMF) and the stellar initial mass function have been noted, which may reveal a fundamental aspect of the star formation process. However, the relation of these "cores", typically observed via their dust continuum emission, and the pre-stellar cores (PSC) that will actually form stars is unclear. Here we propose to measure the PSC mass function by mapping N2D+(3-2) over a contiguous region of an IRDC that we have already observed in N2H+ with CARMA and in which we have already identified at least two relatively massive N2D+ PSCs with ALMA in Cycle 0. We expect to identify ~75 N2D+ cores, and measure masses via mm continuum emission, mid-infrared extinction and virial methods. We will carry out astrochemical modeling of the cores to estimate deuteration ages, which can help de-bias the observed PSC mass function to obtain the true PSC mass function. We will also study the chemical evolution from PSCs to protostellar cores. Finally, we will measure core-to-core kinematics and compare with simulations of molecular cloud turbulence. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2017-10-23T00:00:00.000 |
| 2140 | 2019.2.00068.S | 17 | The 'Missing Link': Gas Accrection Flows in the Galactic Bar toward the Central Molecular Zone | We propose to observe 25 clouds in the Galactic bar with gas temperatures of tens of K and broad lines (>~10km/s) - these clouds are the best candidates for the gas flow that feeds the Central Molecular Zone (CMZ) of our Milky Way. Whereas the CMZ is a well studied region at all wavelengths (including the supermassive black hole Sgr A* and the vigorous star forming region Sgr B2), the streams that feed the CMZ have largely been neglected. Modeling the gas shows that it likely follows x1 and x2 orbits, enforced by the bar potential, with gas accretion at various points and cloud-cloud collision from some dynamical effects like (self-)intersecting orbits and accretion overshooting. We propose to probe these processes by simultaneously observing molecular lines that trace physical parameters such as shocks, turbulence, temperature, ionization etc. The ACA+TP is the perfect telescope for our study as it allows us to probe relatively large regions at molecular clump resolution with adequate sensitivity. The data will form an invaluable grid of cloud properties for improved detailed dynamical models of the inner Galaxy. | Galactic centres/nuclei | Active galaxies | 2024-06-06T21:51:14.000 |
| 2141 | 2017.1.01701.S | 15 | The Edge-On disk of HH 30: How much flatter can it get? | We propose to observe HH~30, a prototypical Edge-On disk, with the maximum resolution that ALMA can provide. We selected Band 6 and configuration C43-10, aiming at 0.02arcsec resolution. HH 30 is the perfect case to observe with ALMA at maximum resolution and obtain the best contraints on the full amount of dust settling of mm-sized particles. This is a key mechanism leading to rapid dust growth and pebble formation but it remains poorly constrained by observations to this date. We already have images at 0.4 and 0.12 arcsec resolution in Bands 4,6 and 7. The image of the disk is, so far, a straight line: HH 30 is perfectly edge-on, and the disk thickness seen by ALMA (mm-sized grains) is still unresolved. Because of its flatness, the surface brightness of the disk is high. This is the best available case to measure directly the amount of vertical dust settling in protoplanteray disks. | Disks around low-mass stars | Disks and planet formation | 2018-11-23T21:31:27.000 |
| 2142 | 2021.1.00379.S | 72 | Unveiling the distribution of the cosmic-rays ionization rate with ALMA | Cosmic rays are a global ionisation source and play a pivotal role in determining the chemical composition and ionisation fraction of the interstellar medium, with critical effects on both the star and planet formation process. However, the cosmic ray ionisation rate (CRIR) represents one of the bottlenecks for astrochemical models, and its determination is one of the most puzzling problems for modern astrophysics. In diffuse clouds, H3+ observations allowed reasonable estimates of CRIR, while for dense clouds, this is not possible due to the lack of rotational transitions, and estimates are strongly biased by the employed model. Recently, a new analytical approach to estimate the CRIR in the densest regions of molecular clouds has been proposed. The latter is model-independent and based on the estimate of the H3+ column density from its deuterated forms, known to be very abundant in dense and cold star-forming regions. With this proposal, we aim to obtain the first high-resolution maps of CRIR in two massive clumps where multiple cores were observed for the first time with ALMA in oH2D+, providing crucial constraints for chemical/physical modelling of star-forming regions. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-05-26T18:09:39.000 |
| 2143 | 2015.1.00561.S | 2 | Does the fine structure constant change with time ? | We propose to use the ALMA Band-6 receivers to obtain deep spectra in the redshifted CI 492 GHz and CO(4-3) 461 GHz transitions from the z=0.88582 lens towards PKS1830-210. A comparison between the redshifts of the fine-structure CI and rotational CO transitions provides a sensitive probe of changes in the fine structure constant and the proton-electron mass ratio. Using existing stringent constraints on changes in the proton-electron mass ratio from the same absorber, the proposed observations will yield the highest sensitivity to changes in the fine structure constant from any astrophysical method and will definitively confirm or deny the variations in the fine structure constant detected with the many-multiplet method. We request 38 minutes of time for this project, including all calibration and overheads. | Gravitational lenses | Cosmology | 2017-07-15T23:41:36.000 |
| 2144 | 2018.1.01434.S | 334 | DEATHSTAR: The S-type stars | Mass loss by a stellar wind is a decisive process for late stellar evolution. Through this wind, Asymptotic Giant Branch (AGB) stars are major contributors of synthesized elements and dust to their surroundings. The wind process is studied using hydrodynamical models with the goal of developing a predictive theory of AGB mass loss. The most reliable method to measure mass-loss rates is through CO line observations, but further progress in this fundamental field is still limited by the large observational uncertainties, where the assumed size of the CO envelope is a major factor. The DEATHSTAR project aims to solve this problem by directly measuring the CO envelope sizes. Data has already been collected for 50 M- and C-type AGB stars. To fully reach the project goals we propose to observe a sample of southern S-type AGB stars in CO(2-1) and (3-2) emission using the ACA in stand-alone mode. With this data we will develop the most accurate description of AGB mass loss to date, uniquely determine the gas-to-dust ratios of the sources, and through the large bandwidths covered in band 6 and 7, provide a goldmine for legacy science for the evolved star science community. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-10-12T10:45:12.000 |
| 2145 | 2015.1.00869.S | 46 | Studying the Late-Time Evolution of SN 1978K | We propose high signal-to-noise observations in ALMA bands 3, 4, 6, and 7 of SN 1978K, a remarkable Type IIn supernova that remains bright at X-ray through radio wavelengths 37 years after its explosion. Motivated by our Australia Telescope Compact Array detections of the target at 34 and 94 GHz in September 2014, we aim to characterise the spectral energy distribution between 90 and 350 GHz. SN 1978K is the first old extragalactic supernova (or young SNR) to be detected in the millimeter, apart from SN 1987A. Thus observations of SN 1978K will serve as a pathfinder for younger supernovae. Furthermore, our ongoing program of multi-wavelength observations has shown that now is a particularly important time to study the source: our recent X-ray and UV/optical observations have shown an onset of chromatic fading, after these remained constant for a decade. | Supernovae (SN) ejecta | Stars and stellar evolution | 2017-12-06T19:36:00.000 |
| 2146 | 2013.1.00032.S | 45 | AGN feedback and molecular line flux ratios in infrared luminous dusty galaxies | We propose molecular line observations of nearby infrared luminous dust/gas-rich galaxies for which the relative energetic importance of AGN and starburst has been quantitatively well-calibrated through previous infrared spectroscopy. Using different feedback from AGNs and starbursts to the surrounding molecular gas, we aim to establish a reliable method to scrutinize optically elusive buried AGNs in dusty galaxies, based on bright molecular line flux ratios at the dust-extinction-free (sub)millimeter wavelength. Our pre-ALMA and ALMA Cycle 0 observations have shown that enhanced HCN emission is empirically an excellent AGN indicator, but its physical origin is unclear. We propose ALMA Cycle 2 observations of these well-calibrated galaxies, at multiple transition lines of HCN/HCO+/HNC, in order to clarify the physical origin (i.e., an HCN abundance enhancement or excitation effect). Our (sub)millimeter energy diagnostic method using bright molecular lines, once established, will have a large potential to understand the interplay between suparmassive blackholes and star-formation in distant infrared luminous galaxies, which are known to dominate the cosmic dust-obscured activity. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2016-08-04T15:17:26.000 |
| 2147 | 2012.1.00532.S | 0 | The structure and properties of the molecular gas in the unique environment of N11B in the Large Magellanic Cloud | We propose observations of 12CO(1-0) in the star forming region N11B in the Large Magellanic Cloud. N11B is a unique case of multiple sequential star formation in a nearby metal-poor system. We intend to examine the structure of the molecular gas with ALMA in this region and to use the synergy between ALMA and Herschel to solve the long-standing paradigm of photodissociation regions (PDRs) in a low-metallicity environment. There is growing evidence that CO traces a small filling factor (<10%) of the interstellar medium (ISM) in the form of small clumps. On the other hand, the photodissociated envelopes can harbor a significant fraction of the molecular gas H2 - necessary to fuel star formation - accountable via the PDR lines, in particular [CII] 158um. ALMA Cycle 1 mosaic capabilities and sensitivity will ensure the detection of CO(1-0) throughout the region probed with Herschel. Our main objectives are to: - identify the CO clumps, measure their size and mass, and study the size distribution as a function of the metal-poor environment (e.g., feedback from the massive stellar clusters and the influence on the propagation of star formation under extremely porous ISM conditions) - examine the [CII]/CO(1-0) ratio throughout N11B and construct a model of the PDRs. We will quantify the mass of dark molecular gas and shed new light on the conversion factor between CO and H2 in a metal-deficient environment | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2015-05-22T18:34:59.000 |
| 2148 | 2021.1.00343.S | 5 | The prospective circumplanetary disk around an accreting circumbinary planet | The combination of sub-mm interferometry with ALMA and high-contrast imaging at visible/infrared wavelengths has opened up the door to study the process of planet formation while it is still ongoing. One prominent example is the PDS 70 system, where the b and c planets have been associated both with strong hydrogen-line emission from MUSE and with point-source counterparts in ALMA, both implying the presence of circumplanetary accretion disks. Recently, very strong hydrogen-line emission has been observed from the circumbinary planet 2M0103 (AB)b. Since the intrinsic properties of the emission are very similar between 2M0103 (AB)b and the PDS 70 planets, their disk properties may also potentially be very similar. Here, we propose ALMA band 7 observations of 2M0103 (AB)b, in order to detect and possibly spatially resolve the disk of an accreting circumbinary planet for the first time. The unique proximity at 47.2 pc and strong evidence of accretion for 2M0103 (AB)b makes it by far the most promising known candidate for detailed studies of the late stages of planet formation and the circumplanetary environment. | Exo-planets | Disks and planet formation | 2024-10-03T10:10:11.000 |
| 2149 | 2019.1.01238.S | 18 | The kpc-scale view to the molecular gas content in `typical' star-forming galaxies at z~1.5 | Sensitive measurements of the CO(2-1) emission line in high-z galaxies at ~kpc-scale are now possible with ALMA. We propose to complement our recently obtained spatially-resolved observations of the CO(2-1) emission for `main-sequence'star-forming galaxies at z~1.5. We already have CO(2-1) unresolved data for the three targets proposed to be observed in this project. These sources are also already observed in Halpha emission from KMOS (KGES survey). This data will guarantee the "success" of our proposed observations in order to put UDS_96844, CDFS_31127 and UDS_124101 in the global context of galaxy evolution. We will be able to perform a spatially-resolved view of the star formation activity, gas dynamics. We will be able to compare the ionized and molecular gas ISM morphologies and dynamics. By comparing the molecular gas masses for these systems with their dynamical masses inferred from two-dimensional kinematic model, we will be able to give upper limits to the CO-to-H2 conversion value in the central parts of 'typical' star-forming galaxies at high-z. The kinematic modelling will also help us to constrain the dark-matter content in the galaxy outkirts. | Galaxy structure & evolution | Galaxy evolution | 2022-11-17T08:21:39.000 |
| 2150 | 2013.1.00349.S | 6 | Spiral Arms and Accretion Motion in the Circumbinary Disk around the Protostellar Binary System L1551 NE | We propose follow-up ALMA Cycle 2 observations of the protostellar binary L1551 NE in the 0.9-mm dust continuum and C18O (3-2) and multiple lines at Band 7. Our ALMA Cycle 0 observation of L1551 NE found intriguing substructures of the circumbinary disk around the protostellar binary in the continuum emission, and non-axisymmetric gas motions in the line emission. Models of circumbinary disks around protostellar binaries make the generic predictions of spiral arms and non-axisymmetric gas motions, and our Cycle 0 results are consistent with those models. The angular resolution of the Cycle 0 data is, however, not high enough to unambiguously unveil the spiral arms and disentangle the gas motions in the spiral arms, inter-arm regions, and the circumstellar disks around the individual protostars. In Cycle 2, with the maximum 1.5 km baselines, we aim to unambiguously unveil the winding spiral arms, and gas motions in the spiral arms, inter-arm regions, and the circumstellar disks at a spatial resolution of ~0.13″. By comparing the Cycle 2 images with our theoretical model, we will study the accretion motion onto the protostellar binary in the circumbinary disk. | Low-mass star formation | ISM and star formation | 2016-08-14T14:42:19.000 |
| 2151 | 2015.1.01522.S | 32 | Polarimetric observations of a complete sample of radio sources | We propose ALMA Band 3 polarimetric observations of a complete sample of 32 sources of the faint (S(20 GHz) > 200 mJy) PACO sample (Bonavera et al. 2011), in the Southern Ecliptic Pole region (ecliptic latitude < -75 dec) to estimate the radio-source contribution to the CMB polarisation power spectrum at 100 GHz in total intensity and polarisation and, by complementing the low frequency observations already obtained with the ATCA, to characterize the polarisation properties of radio source populations up to about 100 GHz. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-02-28T10:43:20.000 |
| 2152 | 2022.1.00642.S | 45 | Rapid Dust Destruction in Quenched Galaxies? A Direct Test of State-of-the-Art Cosmological Simulations | ALMA observations of the submillimeter dust continuum are now in wide community use to measure cold gas masses at early cosmic times. This method relies on an assumed molecular gas-to-dust ratio, with a value =100 typically used. However, the most advanced cosmological simulation to explicitly include dust production and destruction physics finds that dust is preferentially destroyed as galaxies transition to quiescence, resulting in gas-to-dust ratios up to 10,000 or more. If confirmed by observations this finding would be sobering for ALMA submm observing campaigns: not only would dust be extremely difficult to detect, but inferred cold gas masses would be uncertain by orders of magnitude. We propose to directly test this efficient dust destruction, targeting the complete sample of all z~1 quiescent galaxies with existing CO detections to provide an independent handle on the gas mass. Our dust continuum observations will reach 3sigma limits on the gas-to-dust ratio of 500-900 in individual sources, enough to rule out the commonly-assumed value at high confidence. The results of this study could have wide-reaching consequences for current and future ALMA submm surveys. | Galaxy structure & evolution | Galaxy evolution | 2024-02-17T22:18:17.000 |
| 2153 | 2016.1.00641.S | 36 | Search for gas emission from Centaur Chariklo | Centaurs are small objects orbiting between Jupiter and Neptune. They are thought to have originated in the trans-Neptunian region and are keys to understand the history and evolution of the outer Solar System. Chariklo is the largest known Centaur, orbiting between 13.1 and 18.5 AU. A stellar occultation by Chariklo in June 2013 led to the discovery of the existence of two narrow and dense rings surrounding the body. This is the fifth ring system known in the Solar System, and the first one to be discovered around a small object. The formation mechanism of the ring system is unknown; one possibility could be the formation by cometary material ejected from the surface of Chariklo. To date, no cometary activity has been detected in this body as dust coma or gas emission, though recent VLT/SPHERE observations indicate the presence of a faint dust halo around Chariklo. We propose a deep search for CO gas at 230 GHz from Chariklo. Detection would (i) unambiguously reveal cometary activity (ii) constrain ring origin models (iii) address the general question of activity in asteroids and of the "asteroid-comet" continuum. | Solar system - Trans-Neptunian Objects (TNOs), Solar system - Asteroids | Solar system | 2018-10-31T14:19:36.000 |
| 2154 | 2023.1.00443.S | 0 | Delivering the Needed Large Samples of Extremely High SFR Sources at z>6 to Characterize Early Stellar+Black-Hole Growth | CISTERN will enable the largest representative selection of massive star-forming galaxies at z>~6. CISTERN will achieve this by using the dust-insensitive [CII] line to identify companion galaxies around 195 of the brightest QSOs+galaxies spectroscopically confirmed at z>5.9. Already ~50% of the highest SFR z>6 galaxies have been identified this way, but samples are small due to incomplete (~33%) targeting of known QSOs+galaxies. By expanding current targeting of bright z>5.9 sources, CISTERN will triple the size of high-SFR companion galaxy samples to ~75, greatly exceeding even the ASPIRE LP. Thanks to a [CII]-based SFR selection and its size, it will serve as a key z>~6 reference sample, being more immune to dust than JWST selections. It will facilitate detailed probes into the demographics of the highest SFR galaxies and contribution dusty galaxies make to the SFR density, while better characterizing density enhancements around the brightest QSOs+galaxies. Finally, by targeting 195 z>5.9 bright QSOs+galaxies, CISTERN will triple the [CII]+dust data for these sources, improving current probes of AGN demographics and the utility of QSOs for constraining cosmic reionization. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2025-04-10T15:53:35.000 |
| 2155 | 2012.1.00271.S | 4 | Spatial variation of physical and chemical properties for dense clumps at different evolutionary stages in supergiant HII region NGC604 | We propose to obtain high-resolution 13CO(1-0), C18O(1-0), CS(2-1), and 12CO(3-2) maps of the supergiant HII region (GHR) NGC604 in M33 to study the physical and chemical properties of molecular gas at different evolutionary stages in the giant HII region. 13CO(1-0), C18O(1-0) and CS(2-1),and 12CO(3-2) are tracers of total gas, dense clump, and moderately dense clump, respectively. Massive star formation process in galaxies is one of unresolved important issues in recent galactic astronomy, because it governs the energy budget of galaxies as well as chemical evolution of galaxies. In particular, the physical processes in starburst are crucial for the evolution of galaxies. GHRs provide us with an ideal environment to understand the clustered OB star formation process and their impact on the ambient interstellar medium (ISM). In other words, GHR can be ''mini-starburst'', therefore, understanding the star formation process in these GHRs will be also important to study starburst phenomena in various galaxies. GHRs in M33 can be good target to study starburst at GMC or clump scale due to its proximity. Our previous studies (~ a few 10-100 pc) suggest that giant molecular cloud complex associated with the NGC604 is a unique laboratory for the different, especially, early and intermediate stages of the triggered massive star formation associated with the GHR. The next questions are their internal structure; dense molecular gas in a few pc scale, i.e., so called ''clump'' scale. Our requested spatial and spectral (velocity) resolutions (1."2 or 5 pc and 0.7 km/s), and sensitivity (0.2 K at 100 GHz) can detect a typical molecular gas mas of dense clumps, i.e., 1000 Mo. We can simultaneously detect massive dust clump with dust mass of 250Mo by 0.85mm continuum emission and several O9 stars by 3mm continuum emission. The primary goal of this proposal is to obtain a clump-scale view of dense molecular medium in the NGC 604 complex. We will be able to achieve the following goals simultaneously: (1) detection of dense and moderately dense gas clouds at ~ 5 pc scale down to a gas mass sensitivity of ~ 1000 Mo, which are comparable to the properties of ''clumps'' in the Milky Way (2) Identification of the evolutionary phases of the detected dense clumps using our Subaru and other high resolution optical/IR data (3) Investigating the variation of physical and chemical properties of dense clumps along the evolutionary path of massive star formation (4) Verification of line-intensity ratio as indicator of the impact of UV on the dense ISM or evolutionary phase along star forming process at clump-scale This can be the limited but first unbiased survey of clump-scale gas condensations in the different evolutionary phases along the proposed sequential star formation in NGC 604. We will see how clump-scale (<10 pc) properties are related to the larger scale (~ 100 pc) phenomena in the massive star forming regions. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2016-03-25T18:24:58.000 |
| 2156 | 2017.1.00395.S | 163 | Tracking the Properties of Gas Clumps in Luminous Infrared Galaxies Along the Complete Merger Sequence | While galaxies spend most of their lives in a star-forming main sequence (MS), they can also ignite into a starburst mode, often associated with major mergers. It is still unknown, however, whether the extreme star formation (SF) rates achieved during the starburst phase, locally and at high-z, are caused by an increase in SF efficiency and/or the result of a high molecular gas fraction (MGF). Here we propose to obtain ALMA band 6 observations of the CO(2-1) line for 15 local luminous infrared galaxies with available near-IR HST line emission imaging, such that they span the whole merger sequence of galaxies and have integrated molecular gas fractions > 20%, similar to high-z galaxies. The goals of this project are to: (1) track the properties of molecular gas clouds at 70pc scales and establish a connection with the physical parameters describing the evolution of the interaction; (2) estimate the time-scale of cluster formation and disruption and calculate the MGF and SF efficiency of individual gas clumps on and off the MS; (3) constrain models of galaxy formation, which include information on the interstellar medium and stellar feedback on scales of individual gas clumps. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2019-12-06T19:26:50.000 |
| 2157 | 2018.1.01095.S | 47 | Molecular gas chemistry in radio galaxies: the impact of radio jets in NGC 3100 | Spatially-resolved studies of multiple molecular line transitions are powerful tools to investigate the impact of radio jets on the physics and kinematics of the surrounding gas, and nearby objects are exceptional laboratories for this kind of analysis. Such studies are however very sparse and mostly focused on Seyfert galaxies. We propose a multi-species, spatially-resolved study of the radio galaxy NGC 3100 (z~0.009). From previous ALMA Cycle 3 12^CO(2-1) observations in Band 6 we detected a well-resolved disc of 1.6x0.45 kpc^2. The CO disc appears disrupted along the jet axis and hints of non-circular motions (i.e. outflow) are observed along the disc minor axis. These findings make NGC~3100 a best candidate for a detailed jet-cold gas interaction study. We ask to observe other two CO transitions in Band 3 and 7, as well as dense (HCO+ in Band 7) and shock (SiO, HNCO in Band 4) gas tracers. Through these observations we will characterize the physical conditions of the different kinematical components of the molecular gas in different regions of NGC~3100, and assess the impact of the radio jets on the kinematics and chemistry of the immediately surrounding environment. | Outflows, jets, feedback, Early-type galaxies | Active galaxies | 2020-01-21T13:06:58.000 |
| 2158 | 2021.1.00999.S | 1430 | A Complete Molecular Gas Map of M33 with the ACA | We propose a complete CO(2-1) map of the Local Group spiral galaxy M33 on 30 pc scales with the ACA. Our proposed map will include everyyoung stellar cluster, and HII region (in Halpha). We will observe a complete sample of ~1500 GMCs (>10^4 Msol), increasing the current sample of 600 from previous ACA observations of M33's inner disc. This sample will be spatially complete to the HI surface density predicted for H2 formation (Sigma_HI > 10 Msol pc^-2). Our proposed Band 6 observations provide: (1) simultaneous imaging of 12CO/13CO/C18O(2-1) and (2) high velocity resolution (0.7 km/s) observations of molecular clouds matching existing 21-cm HI VLA observations. Combined with an excellent suite of ancillary data we will: (i) use CO and HI to improve GMC lifetime measurements and measure how H2 fraction varies through M33's disc to test H2 formation models; (ii) link atomic and molecular ISM kinematics to determine scales where gas transitions from ordered (large scale) to random (small scale) motions; and (iii) use CO line ratios to probe GMC evolution. Measuring environmental and evolutionary trends requires a large GMC sample that this complete map will provide. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2023-09-23T21:40:50.000 |
| 2159 | 2015.1.00669.S | 38 | Fibers and bundles: dissecting the internal substructure of massive filaments | The B213 cloud in Taurus has been identified as a prototypical star-forming filament by the latest Herschel results. Recent millimeter line observations have revealed the extraordinary level of internal complexity of this filament. Although apparently monolithic when observed at the continuum, the analysis of its gas kinematics demonstrates that B213 is instead formed by a collection of 35 small-scale fibers arranged in a bundle-like configuration. This complex substructure naturally explains the stability of the B213 filament at large scales while it allows its gravitational collapse in only those regions where it becomes locally unstable. In this proposal we aim to explore whether this hierarchical association of "filaments within filaments" can also explain the internal substructure of more massive filamentary clouds like the Orion Integral Shaped Filament. For that, we propose to carry out two 150-pointings ALMA N2H+(1-0) line emission mosaics of the OMC 1 & 2 regions. Complemented by large-scale, high-sensitivity IRAM30m observations, and using our FIVe analysis algorithm, we aim to fully characterize the internal substructure of these two regions down to scales of 0.01pc. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-05-11T22:36:00.000 |
| 2160 | 2013.1.00718.S | 13 | An ALMA 1.3 mm spectroscopic survey in the Hubble Ultra Deep Field | We propose to obtain an unbiased, deep CO/[CII] spectral scan and (parallel) ultra-deep continuum imaging toward a region in the Hubble Ultra Deep Field (UDF) using ALMA in band-6. We aim to encompass a region of 1 arcmin^2 in a 7-point mosaic, covering the entire band-6 through frequency scans, thus comprising the main epoch of galaxy assembly at 0 | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2016-05-06T12:14:31.000 |
| 2161 | 2016.1.01592.S | 14 | Exploring the Evolution of Molecular Clouds in NGC 1566 | We propose to observe the grand design nearby spiral galaxy NGC 1566 in HCN, HCO+, CS and SiO with a resolution of 0.6" (30pc), fine enough to identify giant molecular clouds (GMCs). Star formation rate(SFR) is important parameter of describing molecular cloud evolution. It basically depends on amount of molecular gas. Recently it is suggested that dynamics such as turbulence and streaming motion is important factor of the SFR. It is also reported that star formation efficiency of dense gas is constant both in large scale (entire galactic disk) and in small scale (within individual cloud). However there are no observations for star formation efficiency of the dense gas at a GMC scale(~50pc). It is important to identify the dense clouds in GMCs and derive its star formation efficiency comparing with the large scale gas dynamics such as turbulence and streaming motion. We also investigate environment dependence of cloud properties, deriving the relation between dense gas mass fraction , star formation efficiency, star formation efficiency of dense gas, virtualized parameter, shear strength and stellar feedback. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2018-02-10T15:43:41.000 |
| 2162 | 2015.1.00804.S | 75 | The Galaxy Merger Process: Molecular Gas Properties at the Beginning and the End | The galaxy merger process is still not well understood and more observational constraints are necessary to improve numerical simulations. We propose to observed two mergers (NGC 2623 and Arp 240) at opposite ends of the merger process in several 12CO and 13CO transitions. Combining the proposed observations with existing CO data, we will perform a radiative transfer analysis to constrain the physical conditions of the molecular gas at each merger stage. We will compare the physical conditions with other mergers at different stages to look for trends in the molecular gas properties, CO-to-H2 conversion factor and the [12CO]/[13CO] abundace ratio with merger stage. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-04-19T17:02:41.000 |
| 2163 | 2012.1.00676.S | 0 | The black hole - galaxy mass relationship at redshift 6 | We propose to make [CII] and rest-frame 160 micron continuum observations of a sample of z=6 quasars with observed black hole mass ~10^8 solar masses. The science goal is to measure the dynamical masses of the quasar host galaxies and determine the black hole to galaxy mass ratio at this epoch. Previous work at this redshift has been based on observations of SDSS quasars with black holes > 10^9 solar masses that are subject to a selection bias. Our aims are to measure the strength of the selection bias and hence the true relationship, which is a key constraint on theories of the early co-evolution of galaxies and their central supermassive black holes. The dust continuum luminosity measures the star formation rate to be compared with the black hole accretion rate. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2015-03-04T12:39:44.000 |
| 2164 | 2021.1.00854.S | 112 | Tracing planet-forming pebbles across the water snow line with the synergy of ALMA and JWST | ALMA observations trace the pebble (mm/cm size grains) distributions in the outer parts (>10 au) of protoplanetary disks, but cannot directly inform on the pebble mass delivered into the rocky planet forming region at < 5 au, which has strong implications on the architecture and composition of forming (rocky) planets. Recent work proposed that chemical signatures revealed from mid-IR spectra could provide a synergic view of the evolution and drift of planet-feeding pebbles from the outer to the inner disk. With the launch of JWST, there is an urgent need to complete the upcoming JWST data with complementary ALMA data. We propose to observe 11 disks at 1.3mm with 0.05" resolution, which will complete a total sample of 60 disks that will be observed in multiple approved JWST/MIRI programs, but do not have high-resolution mm images yet. More importantly, our sample will double the number of mm-faint disks, which have bright water emission and are some of the best targets for inner disk chemistry studies. A joint analysis of high quality ALMA and JWST data will allow us to test if the inner disk water vapor is enriched by the inward drift of pebbles in a large and well-balanced sample. | Disks around low-mass stars | Disks and planet formation | 2023-01-12T18:52:29.000 |
| 2165 | 2023.1.01362.S | 0 | Pandora's ELPIS: The Emission-Line Protocluster Imaging Survey of the furthest overdensity beyond Pandora's Cluster | How much of cosmic star formations is obscured by dust at the epoch of reionization (EoR)? Recently, ALMA has revealed the presence of dust out to z ~ 8, and the obscured star formation can be more prominent in a protocluster of galaxies. However, an unbiased search for dusty star-forming galaxies (DSFGs) at z ~ 8 remains a challenging task since virtually all studies that select z ~ 8 sources rely on the Lyman break technique, which biases against DSFGs, and no such overdensities have been identified so far. Here we propose the Emission-Line Protocluster Imaging Survey (ELPIS), a Band 6 [CII]+dust mapping of an 80"X40" area around the most distant known overdensity at z = 7.88 behind Pandora's Cluster, Abell 2744, which was recently confirmed by JWST. Strikingly, the number density of confirmed LBGs is 2-3 dex higher than in the general field, making this field an ideal place for a impartial search for DSFGs that have been overlooked. We will detect tens of DSFGs in addition to a fraction of known LBGs. This will present an order of magnitude increase in the number of known [CII] detections at z ~ 8, allowing us to address the obscured contribution to cosmic star formation. | Galaxy Clusters | Cosmology | 2025-05-10T07:02:30.000 |
| 2166 | 2022.1.00007.S | 0 | Overture to the super maser flare in Orion KL 2024 | A complete picture of Orion KL, the nearest high-mass star-forming region, is crucial in terms of understanding of high-mass star-formation. While it has been studied for a half century, there remains a number of unresolved properties. One of such outstanding characteristics is the super flare of the 22 GHz H2O maser, in which the flux density increases from kilo-Jy to Mega-Jy within a few years. Since the super maser flares were reported in 1985, 1998, and 2011, it would imply a 13-year period possibly caused by episodic dynamical processes. If it really has the periodicity, the next flare will start in 2024. Thus, we propose to start observations from the pre-flare phase in ALMA Cycle 9 to identify origins of the super maser flare. We will image the 183 GHz and 325 GHz H2O masers in Orion KL to compare positions and variabilities of that of the 22 GHz H2O masers. We will also explore a possible powering YSO of the super maser flare using continuum emission. The present study will contribute to understanding of broader context of high-mass star-formation such as time-variable activities of mass accretion and/or ejection, along with the pumping mechanisms in the maser flares. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2025-09-11T10:16:23.000 |
| 2167 | 2017.1.00629.S | 321 | Constraining the cold accretion onto the most massive Black Holes | The properties of the cold gas found in the cores of clusters of galaxies are relatively poorly constrained. Observations of the global emission from the ensemble of cold clouds traced by CO allow us to estimate the total mass and temperature of the gas. However, without information about the size and density of individual clouds, it is not possible to unambiguously determine its contribution to the baryon budget in the cluster core and how it fuels AGN activity. We propose to obtain CO(1-0) absorption observations toward the 23 brightest mm-continuum sources in cluster cores observable with ALMA to determine the properties of a statistically meaningful sample of these clouds. The results from these poor weather observations requested will form the basis of future observations to determine the chemistry and dynamics of these clouds. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2019-09-14T16:20:00.000 |
| 2168 | 2018.1.00627.S | 35 | Searching for hot molecular cores in the extreme outer Galaxy | The recent discovery of a hot molecular core in a nearby low-metallicity galaxy, the Large Magellanic Cloud (LMC), suggests that the galactic metallicity has a significant effect on chemistry in warm and dense molecular gas associated with a protostar. While remarkable chemical differences are reported between the LMC and Galactic hot cores, it is still unclear if the observed chemical characteristics is essentially common in other low-metallicity environments or it is unique only in the LMC. Here we propose ALMA observations to search for hot cores in a star-forming region at the edge of our Galaxy. The proposed target, WB89-789, is an active star-forming region located at the extreme outer Galaxy (galactocentric distance ~20 kpc), where the metallicity is lower than the solar neighborhood by a factor of four. This low metallicity environment, which is common with the LMC, provide us with an ideal laboratory to test the universality of the low-metallicity molecular chemistry observed in the LMC. This proposal aims to elucidate a possible link between metallicity and hot core chemistry, particularly by focusing on properties of complex organic molecules and their parental species. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-08-14T08:16:22.000 |
| 2169 | 2015.1.00113.S | 141 | Arp 220 Nuclear Disks at 50 mas Resolution | We propose ultra-high resolution (50uas, 20pc) imaging of Arp 220, the closest, brightest and best studied ultra-luminous IR galaxy (ULIRG). Our observations in the CO(1-0), (2-1) and (3-2), HCN(4-3), CS(7-6),(5-4) and (2-1) (all with their 13C isotopologues) and the dust continuum will resolve the gas structures and dynamics in the two (hypothesized) nuclear disks of this archetypical ULIRG. The observations will also place significant constraints on possible SMBHs. Indeed, our cycle 1 observations of Arp220 (Scoville et al. 2015), together with our extensive simulations, demonstrate that such extremely high fidelity observations are feasible, that will result in resolutions that exceed previous ULIRG observations by orders of magnitudes in beam area. Tracing a number of key diagnostic lines of the ISM will shed unprecedented insights in the inner workings of this prototypical ULIRG (gas densities, masses, outflows, gas dispersions), that hosts some of the most extreme star formation environments in the universe, both at low and high redshifts. Compact and extended configurations are requested to provide the required image fidelity at the superlative resolution of ALMA. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-07-17T19:55:40.000 |
| 2170 | 2011.0.00039.S | 0 | The ALMA view of the cool dust in an extreme low-metallicity starburst v1.6 | We propose Band 7, extended configuration, continuum observations of the most metal-poor starburst in the local universe, SBS 0335-052E. The starburst in SBS 0335-052E occurs in extreme conditions, dominated by Super Star Clusters (SSCs) which have formed in a relatively pristine interstellar medium (ISM) (12+logO/H=7.2). ALMA's superb sensitivity and spatial resolution can for the first time probe the cool dust in this tiny galaxy, and help understand how metal enrichment and dust production proceed in early stages of galaxy formation. Our analysis of the spectral energy distribution (SED) of this SBS 0335-052E suggests that the dust mass and dust-to-gas ratio (DGR) is highly uncertain; compared with the HI mass, the dust-to-gas ratios (DGRs) range from 3e-7 to 2e-5, much lower than predicted by a linear extrapolation of the DGR variation with metallicity. However, the SED fits are unconstrained, because there have been no detections of cool dust so far. We are likely missing a large fraction of dust mass traced by the cool dust which ALMA can now measure. SBS 0335-052 hosts six Super Star Clusters, spread over roughly 2.6 arcsec in diameter. Most of the star-formation activity occurs in the two brightest clusters, which host almost 10000 O stars in a compact region unresolved by the HST. With ALMA, we can assess the effects of feedback of the massive stars on the dust morphology and the clumping scale of the cool dust in an extreme unenriched ISM. Ultimately, our proposed observations can open a new window on the transition from metal-free star formation in the early universe to the chemically evolved massive galaxies typical of the current epoch. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2013-10-25T08:44:50.000 |
| 2171 | 2015.1.01384.S | 22 | Probing Subsurface Water Ice Reservoirs on Ceres | Water is one of the most significant and abundant tracers to understanding the solar system, because of its direct connection to astrobiology and sensitivity to probing the physical and chemical state of planetary bodies. Ceres is a large reservoir of water in the inner solar system. The recent discovery of active water outgassing from Ceres, and the arrival of NASAs Dawn spacecraft at Ceres, raise the new urgency to determine the thermal environment and characterizing any subsurface water reservoirs on Ceres. We hereby propose observations of Ceres in October 2015 with the aim of constructing complete spatially resolved thermal maps of the object. These maps will allow us to constrain the subsurface temperatures down to the diurnal thermal depth of a few mm, identify the temperature environment that could possibly host stable underground water ice, and search for excessively high thermal inertia that could be a signature of subsurface water ice. This proposal is the start of a 5-year investigation funded by NASA to observe Ceres with ALMA in a full Ceres-year to constrain its subsurface temperature environment down to 0.5-1 m. | Solar system - Planetary surfaces, Solar system - Asteroids | Solar system | 2017-03-02T14:12:50.000 |
| 2172 | 2019.2.00218.S | 126 | ACA Linescan of 2 z>5 SMGs in the CDF-S | We propose ALMA linescans for a complete sample of 58 S(850um)> 1.7 mJy SMGs from an extremely deep SCUBA-2 CDF-S map, all with accurate positions/fluxes from prior band 7 ALMA imaging. We aim to detect 2+ bright CO transitions in the majority of SMGs, establishing firm redshifts (unlocking great potential for individual and stacked spectral constraints from radio to X-ray), robust molecular gas (mass, excitation curves, kinematics, t_depl) and dust properties (mass, temperature) estimates. These precise physical constraints, which are unattainable by UV/opt/NIR methods, will advance our understanding of star formation in this critical flux regime, which accounts for ~30% of the 850um background. The samples completeness and the unsurpassed ancillary data in the central part of the CDF-S (deepest Chandra, Herschel, HST NIR/optical, etc.) make it a unique dataset for understanding the SMGs. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2022-11-01T22:22:03.000 |
| 2173 | 2021.1.01305.S | 10 | Molecular outflows in the epoch of reionization: OH observations of a quasar at z=6.04 | Molecular outflows are important in galaxy evolution owing to their role in regulating star formation and enriching the circumgalactic medium with metal-rich gas and dust. Although molecular outflows have been discovered in many active galactic nuclei and starbursts, evidence in quasars in the Epoch of Reionization (EoR; 6<~z<~20) is scarce. How prominent was feedback in dusty quasars during this epoch? To search for molecular outflows, we propose sensitive OH 119 um observations toward J2054-0005, a quasar at redshift z=6.04. Recently, OH absorption has proved to be a robust tracer of molecular outflows up to z~5, but detections in EoR quasars are notably lacking. Our target exhibits a bright compact continuum source and a prodigious star formation rate of ~1900 Msun/year, making it an ideal object to expect quasar feedback and demonstrate the potential of the OH 119 um line in tracing molecular outflows at z>6. We will estimate the outflow properties, such as kinetic energy and mass outflow rate. The results are expected to provide valuable information for galaxy evolution models. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-08-31T05:05:13.000 |
| 2174 | 2024.1.01137.S | 0 | Zooming into a deeply embedded CPD within the disc of HD163296 | ALMA has revealed that the disc of HD163296 is an exceptional laboratory for studying planet-disc interaction, hosting numerous signatures in both gas and dust emission potentially induced by embedded, yet unseen protoplanets. Recent analysis of Band 6 high-resolution archival data on small organics, HCN and C2H, has demonstrated the presence of circumplanetary material, likely a circumplanetary disc (CPD), co-spatial with a previously reported protoplanet candidate associated with kinematic perturbations traced by CO isotopologue emission. We request deep 0.15'' high spectral resolution observations of HCN in Band 7 to robustly constrain the physical properties of the CPD, including its kinetic temperature, and through radiative transfer modelling, its inclination relative to the host disc. These observations offer a unique opportunity to directly witness the assembly of a Jupiter-like planet, and are anticipated to provide missing links between circumplanetary gas structure and the dynamical and chemical environment surrounding the immediate vicinity of planet-forming regions. | Disks around high-mass stars, Exo-planets | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 2175 | 2021.1.00162.S | 5 | Constraining the Jupiter Equatorial Oscillation from ALMA direct wind measurements | An equatorial quasi-periodic oscillation in temperature and wind direction was discovered in the 1950s in Earth's stratosphere. Comparable equatorial stratospheric oscillations exist in Jupiter and Saturn. Our project aims at better understanding the processes that cause and maintain the Jupiter Equatorial Oscillation (JEO), which occurs between 1 and 30 mbar. We propose to map the winds around Jupiter's equator at two different stratospheric levels. We will observe at 1 mbar, using HCN(4-3), and 5 mbar, using CO(3-2). These two levels in the stratosphere are, respectively, the levels where the JEO is generated and a level where the JEO winds can reach ~200 m/s. We also propose to produce two wind maps separated by 6 months (March and September 2022) to investigate how the vertical structure of the JEO zonal winds evolves at different phases of the oscillation. | Solar system - Comets | Solar system | 2024-01-03T18:06:24.000 |
| 2176 | 2018.1.01305.S | 33 | Resolving stellar IMF and evolution modes in dusty starbursts at high redshift | We request ALMA observing time in order to built on our success of using it as a powerful new probe of the stellar Initial Mass Function (IMF) in dusty starburst galaxies (Zhang et al. 2018, Nature). Isotopes of CNO elements are solely produced by stellar nucleosynthesis, and ejected into interstellar medium (ISM) imprinted with IMF. Accomplished with galactic chemical evolution modelling, which is well-benchmarked against rich data in the Milky Way, the 13CO/C18O line ratio has been demonstrated as a powerful tool for probing stellar IMF in galaxies across cosmic time. This opens up a unique new window of exploring fundamental issues of galaxy evolution in the Early Universe, exploiting recent advances in stellar physics. We propose to perform deep observations of 13CO and C18O lines in two strongly lensed starbursts, with mid-resolution, to a) resolve spatial variations of the IMF within them, b) compare IMF and SFR surface density in extreme conditions on kpc scales, and c) connect the resolved IMF distribution with those found in local early-type galaxies, by tracing the evolution of both stars and ISM across cosmic time. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2019-11-28T14:35:47.000 |
| 2177 | 2022.1.01604.S | 9 | A new, fast, ultradeep constraint on the ISM content of the first generations of massive quiescent galaxies. | The question of whether quenching requires complete gas depletion does not have a clear answer yet. The literature offers contrasting results, whose intepretation requires large statistical samples that are not yet available. We propose to take advantage of a new, compelling method to measure the total gas fraction of high-z quiescent galaxies by using the brightest molecular gas mass tracer, i.e. the [CII] 158 microns fine-structure emission line. This line has long been overlooked since it is predominantly used for star-forming galaxies. However, it becomes particularly useful for quiescent galaxies at high-z since these are often selected to have suppressed sSFRs - but not absent - with respect to main sequence galaxies. By exploting ALMA bands 8-9-10 we will observe gas fractions down to 1% (without strictly requiring strong lensing) in 8 spectroscopically confirmed, well-studied, massive quiescent galaxies at 1.22.9. | Galaxy structure & evolution | Galaxy evolution | 2024-09-22T13:43:42.000 |
| 2178 | 2017.1.01401.S | 13 | Unvealing the true nature of the subluminous young stellar object Par-Lup3-4 | Par-Lup3-4, located close to the brown dwarf limit is an underluminous object for its spectral type which is also accreting. We propose Band 7 observations of CO(3-2) and continuum of Par-Lup3-4 to study the morphology and the physical parameters of the dust and gas disk surrounding the object. These observations will also allow us to confirm the low velocity molecular outflow that was detected recently in previous ALMA band 6 observations. Using the continuum emission from the dust we will measure the spectral index between 1.3 mm (using previous ALMA b6 observations) and 870 microns to probe possible evidence or grain growth inside the disk. Another important goal is to study the kinematics of the disk and estimate the dynamical mass of ParLup3-4, which will reveal the true nature of this object in the limit of the substellar regime. This proposal requesting only 2.17 h time, will provide unique information on the origin of low mass stars close to the brown dwarf boundary. | Low-mass star formation | ISM and star formation | 2019-04-12T08:37:04.000 |
| 2179 | 2023.1.00601.S | 0 | Probing molecular gas in the radiogalaxy Coma A, a unique local case of jet triggered star formation | We propose to obtain CO(1-0) observations of the nearby radio galaxy Coma A (z=0.085). The VLT/MUSE data revealed a spectacular nebula of ionized gas enshrouding the radio source and the presence of young stars located as far as 50 kpc from the nucleus. The shocks induced by the expansion of the radio lobes are causing the collapse of cold gas clouds, triggering star formation (SF). With the proposed ALMA observations we will explore the distribution of the molecular gas, the reservoir of material needed for star forming regions, and study its kinematics. This will enable us to probe the effects of the active nucleus on the surrounding medium to understand whether the radio source, that is currently forming stars, will cause the sterilization and quenching of future SF in the host. Coma A is a unique source in the local Universe and it represents a perfect laboratory to study jet-triggered SF, a process that has been fundamental for the evolution of galaxies in earlier epochs. The proposed observations represent an exceptional opportunity to study in detail the physical interaction between the active nucleus and its surroundings and to explore the effects of positive feedback. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-11-13T12:29:55.000 |
| 2180 | 2019.1.00473.S | 6 | Ionized Gas, Radiation Field, Masses, and Dust Temperature in Forming Massive Clusters in the NGC253 Starburst | Our ALMA observations in B7 at 0.1" resolution identified massive super star clusters (SSCs) in the process of formation in the core of the NGC253 starburst (Leroy et al. 2018). Follow up at 0.03" measured sizes and uncovered outflows from these SSCs (Levy et al., in prep.). The characterization of these clusters is needed to understand the high-efficiency "starburst mode" of star formation, the life cycle of massive clusters, and the effects of massive-star feedback on star forming clouds. This proposal aims to: 1) directly measure the ionizing photon flux and synchrotron emission in these objects, which impact the stellar masses and ages of the clusters, 2) constrain the dust optical depth and dramatically improve estimates for the temperature and gas mass of these sources, and 3) measure the sizes of the HII regions associated with these SSCs and to search for ionized gas outflows. Our observations also yield a direct constraint on the hardness of the ionizing radiation field and on the high mass end of the stellar IMF in these SSCs. These data are key to build a picture of the dominant star formation mechanism in starbursting systems at low and high redshift. | Starbursts, star formation | Active galaxies | 2022-10-19T22:26:01.000 |
| 2181 | 2022.1.01603.S | 20 | ALMA Cycle9: Chemical differentiation between starless twin substructures | The self-gravitating substructures in the starless cores are expected to form multiple stellar systems. However, such substructures at starless phase is rarely seen. We propose to observe G205.46-14.56M3, a starless core habors two substructures with a separation of 1200au, consistent with the turbulence-dominated core fragmentation scenario. As N2D+ is depleted, we propose to use H2D+ and D2H+ to trace the central dense region. It has been shown that the ortho-H2D+/para-D2H+ ratio is a reliable collapsing timescale indicator (Bovino et al. 2021). Therefore, we propose to observe ortho-H2D+ and para-D2H+ towards two substructures to derive their physical properties. The ratio will give us the ages of the two substructures of G205.46-14.56M3. By comparing the ages with the free-fall time, we test if they follow the rapid collapse as predicted by the turbulent-fragmentation theory. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2025-11-13T04:34:03.000 |
| 2182 | 2019.1.00582.S | 6 | WISDOM: NGC0383: The Most Accurate Extragalactic Supermassive Black Hole Mass Ever Measured | We propose to make the most accurate supermassive black hole (SMBH) mass measurement ever beyond our own Milky Way in the radio galaxy NGC0383 (radio source 3C31), also reaching closer to the SMBH than any other measurement (except again the Milky Way and the recent EHT measurement of the M87 SMBH). With 0.024" resolution, we can resolve the molecular gas accretion disc down to 25,000 Schwarzschild radii, a factor of 2 closer to the BH than the best existing megamaser measurement. In addition to the extremely precise SMBH mass measurement, we will probe with unprecedented detail the region of NGC0383 within the SMBH sphere of influence, all of which is within the Bondi radius. We will search for signatures of warps and/or non-circular motions that may be funnelling gas towards the SMBH, shedding light on the feeding of such radio-loud/jetted systems, and we will attempt to constrain accretion disc models and their connection to the larger scale disks/fuel reservoirs, also probed here. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2022-10-29T18:53:45.000 |
| 2183 | 2021.2.00180.S | 183 | Resolving systematics in the Planck sub-millimetre spectra of radio-loud AGNs | We have found the possible dust contamination as denoted by the sub-millimetre excess in the radio spectra of bright AGNs observed during the Planck campaign. The origin of the dust in most cases seem to be intrinsic as they are unaffected by the Galactic dust. A majority of sources in the sample showing this trait are blazars, which as per the definition are old ellipticals with no significant traces of dust. The SEDs of these sources seem to be unlike the starburst galaxies that are known to have higher gas/dust temperatures. We propose continuum observations of the dust emission in 16 AGNs. Our goal is to characterise the nature and origin of the sub-mm flux in terms of the particle acceleration in addition to the dust in these objects and re-visit the evolutionary stage of AGNs in elliptical galaxies. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-07-12T23:47:55.000 |
| 2184 | 2022.1.01220.S | 9 | Star Formation Under the Cosmic Microscope with JWST + ALMA | The James Webb Space Telescope (JWST), through the Directors Discretionary Early Release Science (ERS) Program, is going to spend 55 hours observing four gravitationally lensed starforming galaxies to spatially resolve the stellar components and the star formation in galaxies across the peak of cosmic star formation (1.3 | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-02-24T14:59:18.000 |
| 2185 | 2018.1.01113.S | 43 | The Nature of the Central Disk in V Hya: A Carbon Star Ejecting High-Velocity Bullets | The carbon star V Hya is experiencing heavy mass loss as it undergoes the transition from an AGB star to a bipolar planetary nebula (PN), and is possibly the earliest object known in this brief phase, which is so short that few nearby stars are likely to be caught in the act. Our STIS/HST data show a 25-yr history of high-velocity (>200 km/s) bullet-like ejections from the star. SMA CO observations with ~3.5" resolution also reveal an extended high-velocity, collimated outflow (aligned E-W) and a N-S elongated dense waist (size 8" in CO 3-2) on ~100-250 yr timescales. Our coronagraphic polarimetric imaging at 1 micron shows an inclined disk of size 0.6" (or 240 AU) at the center of the waist. We propose to observe the CO J=3-2, 2-1 lines and 0.87-1.3 mm dust continuum in V Hya at ~0.1" resolution to (a) determine whether this disk is rotating or expanding, and to constrain its mass, (b) study CO bullets close to the central source. These observations offer us an unprecedented opportunity to test binary interaction models for making the jet engines that launch the jet-like outflows that produce bipolar PNe outflows, and the disks that are the launch-sites of these outflows. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2022-03-01T00:00:00.000 |
| 2186 | 2013.1.00151.S | 86 | The gas content and gas depletion time of massive, normal star forming galaxies beyond z=3 | We request rest-frame ~250um continuum observations of a complete sample of 86 massive (log(M_stellar/M_sun) > 10.5) normal star-forming, i.e. main sequence, galaxies at high redshift in an epoch of increasing SFR density (z~3-4) identified in the 2 sq.deg COSMOS field. Using our new, empirically calibrated correlation between mono-chromatic sub-mm luminosity and total gas content we will measure the cool gas mass in these systems. Combined with estimations of their star formation rates from the IR spectral energy distribution (and incoming high-sensitivity Jansky VLA radio continuum imaging), the gas depletion time, or its inverse - the star formation efficiency, of each galaxy will be derived. The proposed observations will provide the first solid measurement of the mean depletion time for normal star-forming galaxies beyond the peak of star formation activity (at z~2-3). A reduced depletion time (relative to local star-forming galaxies) has been inferred for z~1-2.5 samples, but conflicting results based on small (< 5) samples exist beyond these redshifts. These proposed observations are vital in providing the necessary constraints for current galaxy evolution models. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2016-03-10T14:05:13.000 |
| 2187 | 2018.1.01034.T | 66 | Constraining Jet Formation and Evolution with X-ray Binaries | Relativistic jets launched by accreting black holes can affect star formation, galaxy evolution and even the distribution of matter in the universe. Therefore, it is essential that we understand the process of accretion and the physics of these accretion-fed outflows. Black hole X-ray binaries (BHXBs) provide ideal laboratories for probing jet phenomena due to their rapid (day-week) evolution timescales. In particular, broad-band spectral measurements of jet emission in BHXBs during bright outburst periods allow us to constrain the physical conditions in the jet, which can then be coupled to the properties of the accretion flow, probing the mechanisms that govern how jets are launched and quenched. The mm/sub-mm regime bridges a crucial gap between radio and IR frequencies, as data in this regime are essential when performing detailed spectral modelling. We propose targeting the next outbursting BHXB with ALMA ToO observations, to accurately measure the evolving mm/sub-mm flux. Coupled with our exceptional multi-wavelength coverage, we will constrain the dynamic broad-band spectral energy distribution in BHXBs with unparalleled accuracy. | Black holes, Transients | Stars and stellar evolution | 2020-08-28T16:21:10.000 |
| 2188 | 2017.1.00373.S | 119 | Molecular gas and dust in the reionization epoch: massive vigorously star forming galaxies at z~7 | Using state of the art FIR/mm photometry in the COSMOS field, we have discovered and solidly detected four FIR/mm luminous galaxies that could be the most distant ever known, with photometric redshift z~7 and possibly higher. Their FIR/mm colors are even redder than the most distant known FIR/mm galaxy HFLS-3 at z=6.337, while their large stellar mass and dust reservoirs make the redshift confirmation the most important step to proceed. We propose to use ALMA to confirm their very high redshifts via detection of multiple CO (and other weaker) transitions in Band 3 and with final confirmation via [CII] in Band 6. This project will be strongly constraining the earliest epochs of massive galaxy formation in the young Universe, unveiling the existence of vigorous star forming events that were building the first generation of ultra-massive galaxies, progenitors of local giant ellipticals. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-01-27T00:00:00.000 |
| 2189 | 2016.1.00928.S | 192 | Early Stages of Dense Core Evolution | With this ACA standalone proposal, we intend to survey dense cores aiming at investigating the evolution of density profiles at the early collapsing phases. Evolution of low-mass pre-stellar cores is characterized by the radial density profile. Our ALMA observations toward MC27, which is at very early stage of the low-mass multiple star formation in Taurus, shows density enhancement even at the very center while most of the other pre-stellar cores have a flat inner density profile at r < 1000 AU. We investigated the dust column density profile observed by large aperture single dish telescopes toward dense cores at d~150pc, and selected 16 targets as candidates for evolved starless cores that are very close to protostar forming phase. The ACA can look into the central part of each core down to ~5" (~ 750 AU) where the density exceeds 10^6 cm^-3, which is the characteristic density of the threshold for the dynamical collapse. The outcome of this survey will tell us the initial conditions of dense cores evolving toward star formation under the dynamical collapsing phase. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-03-25T00:00:00.000 |
| 2190 | 2017.1.01674.S | 22 | The resolved view to the molecular gas content in normal disks galaxies at z = 1.46 | Sensitive measurements of CO(2--1) emission line of high-z galaxies at ~kpc-scale is possible with ALMA. We propose to complement our recently obtained SINFONI AO-assisted observations of Halpha emission line of star-forming galaxies at z = 1.46 (SHiZELS survey) with a CO line emission map at matched resolution. We already have CO unresolved data for two targets within the SHiZELS survey. This data will guarantee the "success" of our proposed observations in order to put SHiZELS-8 and COS-30 in the global context of galaxy evolution through a resolved and unique view to the efficiency of star formation (SFR/M_H2) and its relationship to the star formation activity, gas dynamics of the galaxy and the clumpiness properties measured from Halpha emission line and its progenitors seen in CO emission line. By comparing the molecular masses for those systems with its dynamical masses inferred from dynamical models we will be able to give upper limits to the CO-to-H2 conversion value on 'typical' star-forming galaxies at high-z. These observations are indended to be part of my PhD thesis, a project which exploits IFU-AO data to understand the origin of clumpy-disk galaxies at high-z. | Galaxy structure & evolution | Galaxy evolution | 2018-12-19T17:19:01.000 |
| 2191 | 2021.1.01611.S | 13 | CI and high-J CO emission from jet-impacted clouds in IC5063: cosmic ray vs. shock heating and their impact on X_CO | Shocks and cosmic rays (CRs) are dominant pathways of feedback-ISM coupling in jet-driven outflows, that differently affect the molecular gas. Shocks drive hotter, thinner molecular outflows than CRs, requiring lower X_CO factors to provide the outflow mass. To overcome this uncertainty, which can be as high as 1 order of magnitude, we will determine X_CO in the galaxy IC5063 - a prototype for jet-driven outflows - by means of SLED fitting. We request CO(6-5), (7-6), CI(2-1), and HCO+(8-7) data that, combined with previous low-J CO and HCO+ data, will enable us to model the line emission via astrochemical, thermally-balanced radiative transfer calculations using CRs and shocks as heating sources. Once the shock- vs. CR- excited fraction of the clouds is known and X_CO is determined, the molecular mass content of the flow will be found. We will compare molecular and atomic (CI-based) masses to evaluate in which phase does most of the gas get accelerated. With our calculations also providing the cloud density and temperature, we will study how pressure changes associated with the jet passage lead to the evaporation of molecular clouds and to the flow mass loading. | Outflows, jets, feedback | Active galaxies | 2023-05-17T11:27:52.000 |
| 2192 | 2017.1.01311.S | 18 | Remote Detection of Organics in Enceladus' Plume | Enceladus, one of Saturn's major moons, is the source of a spectacular water plume originating from a global sub-surface ocean. This plume provides a unique opportunity to trace the composition of an underground water reservoir in the outer Solar System remotely. Excitingly, Cassini has measured high abundances of small organic molecules such as HCN and H2CO in the plume, suggestive of a rich underwater organic chemistry. Identification of salts and molecular H2 in the plume has drawn comparisons to the hydrothermal vent environments in Earth's oceans. More detailed and confident characterization of the plume will be difficult, however, as the Cassini mission is ending and no additional flybys will be conducted. Additionally, there is a persistent worry that some of the organics Cassini is `measuring' may be residual from Titan flybys. We therefore propose to use ALMA to obtain an independent data set securing the existence of the most detectable plume organic, HCN. In addition to providing unambiguous evidence of organics in Enceladus' plume, detection of HCN will establish ALMA as a powerful instrument for remote monitoring of the plume composition and its temporal evolution. | Solar system - Planetary atmospheres | Solar system | 2021-01-08T19:13:37.000 |
| 2193 | 2018.1.00973.S | 16 | Probing the effects of a tidal encounter on the sub-structure of a protoplanetary disk | RW Aur is a T Tauri star that has very recently undergone a tidal encounter with star B, which is also hosting circumstellar material. This object provides the unique opportunity to explore the impact of a star-disk fly-by in perturbing and disrupting part of the protoplanetary disk orbiting a new born star. Whereas this event is extremely rare in low mass star forming regions, it is expected to occur more frequently in dense and massive young associations, which are however too far for disks to be explored at high spatial resolution. How these impulsive events affect the angular momentum evolution of disks, the accretion rate onto the star and ultimately the planet formation potential of protoplanetary disks is still an open question. In this context, the spectacular RW Aurigae system offers the opportunity of a rare insight into this question. With this proposal we aim to probe the effects of the tidal encounter onto the circumprimary and circumsecondary disks, retrace past orbital interactions, and identify possible outflows triggered by the encounter. | Disks around low-mass stars | Disks and planet formation | 2020-01-10T10:17:50.000 |
| 2194 | 2016.1.01290.V | 0 | Pinpointing the Highly Magnetized Twin-Jet Base Near a Supermassive Black Hole | We propose to observe the innermost region of the nearby galaxy NGC 1052 with the EHT and ALMA37 at Band 6 to probe the origin of the twin jet and potentially the acretion disk region. The source is located a distance of 19 Mpc, similar to M87. In contrast with the one-sided jet of M87, NGC1052 shows a twin jet with both the jet and counterjet bases being visible and unaffected by differential Doppler boosting. Using VLBI at 3mm wavelengths, we have recently shown that the twin jets are detectable and extend from a bright and compact central feature. This marks the location of the black hole where we estimate magnetic fields between 360 G and 70000 G to reside. VLBI with EHT+ALMA at Band 6 will provide unprecedented angular resolution and sensitivity that are vital to directly investigate the region where both jets intitially form in greater detail than any previous observation. The morphology, close proximity and strong radio emission makes NGC1052 a prime target to examine the formation of a jet powered by a supermassive black hole at scales of several hundreds of gravitational radii without Doppler boosting complications. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-10-20T14:57:17.000 |
| 2195 | 2012.1.00323.S | 0 | The nature of the ISM in galaxies during the star-formation activity peak of the Universe v2 | The nature of the ISM in typical star-forming (SF) galaxies during the peak in SF activity of the Universe (z = 1-2) is still an open question. It is unclear what the characteristic ISM properties of typical SF galaxies is at z∼1. We propose to observe CO and C lines to determine the dominant physical properties (density, temperature, local radiation field, carbon abundance) of the star-forming ISM in three star-forming galaxies at z ∼ 1.2. The proposed targets are typical examples of the galaxies that are responsible for the bulk of SF during the SF peak of the Universe. These observations can reveal if the physical state of the ISM in such galaxies is similar to local counterparts – a scaled up version of typical nearby galaxies – or significantly different. These observations are the first such attempt towards a detailed understanding of the nature of the ISM in typical star-forming galaxies during the z =1-2 SF peak. | Galaxy structure & evolution | Galaxy evolution | 2015-04-16T14:56:06.000 |
| 2196 | 2015.1.01096.S | 52 | ISM and Kinematics of a Luminous UV-Selected Galaxy in the EOR | Recent ALMA observations have successfully pushed the detections of [CII] from normal star-forming galaxies to z ~ 5-6. Here we propose to further push this into the epoch of reionization (EOR). We will conduct sensitive Band-6 observations to detect the [CII] and far-IR continuum from a carefully chosen z ~ 7 Lyman-break galaxy in the HUDF. The galaxy is unanimously agreed by many groups to be at z ~ 7. It is among the brightest z ~ 7 galaxies and has a star formation rate of up to 110 Msun/yr. It is thus the best candidate to host strong [CII] emission. Its morphology shows hint of galactic interaction. Our observing strategy does not only provide the sensitivity to detect the [CII] line, but also the frequency coverage to encompass any potential redshift uncertainties and velocity offsets between its Ly-alpha and [CII] lines. Our ALMA observations will pin down its redshift and reveal the potentially very interesting kinematics. The [CII] and far-IR continuum results will allow us to test the dust properties, obscured star formation, and the nature of UV extinction in this galaxy. These will lead to a better understanding of the sources of the ionizing photons in the EOR. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2017-06-02T12:03:11.000 |
| 2197 | 2015.1.00263.S | 3 | Multi-phase outflows in ULIRGs: Mapping the massive cold component | Using H2 2.12micron integral-field spectroscopy (IFS), we have recently characterized the hot molecular component of massive outflows in local IR bright starbursts. In particular, high velocity (~1000 km/s, FWZI) hot molecular outflows extended over 2-3 kpc regions have been identified in three low-z ultra-luminous infrared galaxies (ULIRGs). Based on our previous works (Emonts+14, García-Burillo+15), we predict total cold molecular outflowing masses of ~10^8 Msun and outflow rates of 15-200 Msun/yr. Here we propose to obtain deep 0.35" CO(2-1) images of these three ULIRGs to: (i) map the massive cold molecular phase of the outflows; (ii) establish the mass loading and momentum boost factors; (iii) and, for the first time, determine the multi-phase (cold/hot molecular and ionized) sub-kpc structure of the outflows in the most extreme local star-forming galaxies. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2017-10-22T02:28:25.000 |
| 2198 | 2016.1.00236.T | 140 | Unlensed HyLIRG systems from the South Pole Telescope 2500deg^2 survey | From a 2500 degree^2 survey, the South Pole Telescope (SPT) has detected at 1.4mm, ~100 bright high redshift star forming galaxies. Most of these are strongly lensed ULIRGs, however three are candidates for unlensed, extreme hyper-luminous galaxies. We propose to map these systems in ISM diagnostic lines, resolving and detecting all known continuum components. With redshifts of z=4.2, 4.3, 5.7, we can efficiently obtain band6/7 C+/N+ measurements, along with deep mid-J CO. They represent the record holders for the most luminous systems in the Universe (S850~60mJy in the LABOCA beam). Our observations will characterize these systems, going well beyond the ALMA subcomponents already detected in a Band-7 mapping program. Our main scientific goals are (1) detect all subcomponents in continuum and CO which make up the single dish fluxes, (2) constrain the ISM metallicity through the C+/N+ line ratio. (3) further elucidate the `proto-cluster' aspect of these systems by searching for lines from additional faint S850~1-2mJy sources identified in the Band-7 imaging (and beyond), if they lie at the same redshifts, completely characterizing these systems in molecular gas. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-01-31T01:23:03.000 |
| 2199 | 2013.1.00403.S | 3 | Sub-Arcsec Molecular Gas Imaging of the z=2.8 Submillimeter Galaxy SMM J02399-0136 | We propose sub-arcsec imaging of the molecular gas in the z=2.8 submillimeter galaxy (SMG) SMM J02399-0136, the very first SMG discovered with a confirmed counterpart. This remarkable system is a merger of two hyper-luminous infrared sources with AGN feedback that appears to be enhancing the star-formation activity in the system. We request Band-3 and Band-6 imaging observations with a resolution of 0.45" (~1.5 kpc in the source frame), which is sufficient to distinguish between the various components of the system and to study the possible interaction of the QSO with the red starburst region as well as the surrounding large blue Ly-alpha cloud. We propose to observe the CO(3-2), HCN(4-3), HCO+(4-3), CO(7-6), and [CI] spectral lines to determine the molecular gas mass, gas excitation, kinematics, dense-gas fraction, and star-formation efficiencies of the system. The 3.3 mm and 1.3 mm continuum observations when combined with the archival ALMA Band-9 data will reveal the distribution of the dust mass associated with the various components. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-09-05T05:21:21.000 |
| 2200 | 2017.1.01460.S | 71 | Probing transitional disks with a gap of the Solar-system's planetary orbital radii | We propose band 6 observations (including dust continuum, the J=2-1 transitions of 12CO, 13CO, and C18O) at a spatial resolution of 0.03 arcsec of three transitional disk systems. Our targets have relatively small gaps with r<0.15 arcsec corresponding to r<20AU at typical star forming regions, and similar orbital radii of Uranus/Neptune in our Solar system. Hence, probing transitional disks with a relatively small gap could guide our understanding of planet formation of giant planets in our Solar system. With a high spatial resolution of 0.03 arcsec, our proposed observations enable us to look for and examine fine structures such as multi-gaps, asymmetries, inner disks and streamers. By comparing our results with literature studies of transitional disks with a relatively large gap at r>0.3 arcsec, we could test whether the size of gap is a critical parameter in determining disk sub-structures. By comparing our results with literature studies of transitional disks with a relatively large gap of r>0.3 arcsec, we could test whether the size of gap is a critical parameter in determining disk sub-structures. As by-products, we will study CO gas disks as well. | Disks around low-mass stars | Disks and planet formation | 2019-11-22T23:37:37.000 |
| 2201 | 2019.1.00129.S | 6 | Investigating the Multi-Phase ISM in SDP.11 at z ~ 1.8: Gas Physics on Sub-kpc Scales Using Gravitational Lensing | We propose a detailed study of the ionized, atomic, and molecular gas in SDP.11, a gravitationally lensed, high-z, Ultra-Luminous Infrared Galaxy (ULIRG) analog, at z=1.783. The combination of this fortuitous lensing configuration and redshift allow us to map the [CI] 609 um, [CI] 370 um, CO(4-3), CO(7-6), and [NII] 122 um lines with ALMA, at sub-kiloparsec resolution. These lines, combined with our existing [CII] ALMA observations, ionized gas lines from Herschel, and multi-band radio free-free emission data, will allow us to estimate the ambient stellar UV radiation field strength, PDR gas densities, molecular gas density, temperature and mass, dust mass and temperature, and absolute [N/H] abundances, at sub-kiloparsec resolution across the source, as well as to determine the source-averaged stellar radiation field hardness. By probing the gas physics of SDP.11 in all phases of the ISM, ionized, atomic, and molecular, we will learn more about the ways in which massive galaxies rapidly produced their stars near the peak of the cosmic star formation history. | Starburst galaxies, Gravitational lenses | Active galaxies | 2022-06-17T21:19:36.000 |
| 2202 | 2013.1.00212.S | 8 | Detailed molecular gas distribution of an active star forming region within a low-metallicity environment: CO/CI observations of N83 in the Small Magellanic Cloud (SMC) | The aim of this observation is to reveal for the first time the detailed molecular gas distribution of an active star forming region within a low-metallicity environment to understand the formation and structure of GMCs as well as the star-formation process at low metalicity. We propose mosaic observations toward a molecular clump associated with the active star forming region N83 in the SMC in the J=2-1, 3-2 lines of 12CO and 13CO, and [CI] with a final angular resolution of 1.5 arcsec, corresponding to a spatial resolution of 0.44 pc. CO observations will be used to precisely determine the density and temperature of the gas, and in combination with the velocity information, we can investigate the dynamics of hot-dense molecular clumps associated with HII regions and cold-dense molecular clumps prior to massive star formation. [CI] line is also another important probe to reveal the distribution of molecular gas without CO emission, being a significant mass component of the cloud, affecting the system's self-gravity and providing an additional supply of gas to fuel star formation, and also a key to understand the variations of the CO-to-H2 conversion factor. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2016-08-12T16:39:30.000 |
| 2203 | 2019.1.01148.S | 18 | Where's the dust? 870um in Strongly Lensed z~2 Normal Galaxies | We propose to observe six z~2 gravitationally-lensed "normal"/Main Sequence galaxies selected from Saintonge et al. (2013) and Dessauges-Zavadsky et al. (2015) at 870um in order to determine the location of the dust emission. So far, Tadaki et al. (2017) has published the largest sample of resolved dust observations of z~2 Main Sequence galaxies, and found uniformly compact dust emission suggestive of compact star formation growing a central bulge. However, strongly lensed Main Sequence galaxies at similar redhsift have shown much more extended dust emission that traces the UV and stellar mass. By undertaking deep 1" resolution observations of a sample with known IR SEDs, we hope to better understand the prevalence of extended low surface brightness dust emission in "normal" z~2 galaxies. In addition, due to the fact that the proposed sample is lensed, even at this modest resolution we will also be able to address the spatially resolved Schmidt-Kennciutt relation and whether patchy obscuration drives variation in the IRX-beta relation. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2021-04-21T20:37:35.000 |
| 2204 | 2011.0.00013.SV | 0 | Science verification observation of Juno | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Solar system - Asteroids | Solar system | 2016-06-24T14:02:07.000 |
| 2205 | 2024.1.00933.S | 0 | Towards a direct measurement of quasar feedback via the tSZE: hyper-luminous quasar J1549 and its companion | Despite recent discoveries of quasar feedback in action, the amount of energy that an active nucleus is capable of injecting into the extended interstellar medium (ISM) remains unknown. The most mysterious component of quasar feedback is the lowest density, hot volume-filling gas. There are tentative detections of this component via its thermal Sunyaev-Zel'dovich (tSZ) effect through stacking and targeted measurements, but the results remain controversial. There is no consensus on how winds couple to the ISM or what is their physical extent into the circumgalactic medium. Existing observations of a z=2.74 hyperluminous quasar J1549 and its nearby (z=2.363, D=20 kpc) companion reveal a tentative signature of the tSZ effect impacting their spectral energy distributions. We request ~1 resolution observations in ALMA bands 3, 7, and 8 to fully characterize emission components of the quasar and its companion, as well as separate these components from their surroundings to probe the tSZ effect. Additional high impact science goals of this program include full characterization of the dust emission properties, star formation rates, and CO spectral line energy distribution of both targets. | Outflows, jets, feedback | Active galaxies | 3000-01-01T00:00:00.000 |
| 2206 | 2024.1.00551.S | 0 | Probing the Host Galaxies of 45 Broad-line Little Red Dots at zspec =4.13-8.50 with ALMA | We propose the first systematic ALMA census of the [CII] and dust continuum in 45 red-color compact objects, known as Little Red Dots (LRDs), at zspec=4.13-8.50, whose AGN origin has been spectroscopically confirmed by recent JWST observations. Despite their surprising abundance, the physical properties of LRDs' host galaxies remain unknown due to potentially significant dust obscuration. Building upon lessons from recent submm/mm follow-up studies of UV-faint dusty quasars/AGNs, we aim to unveil the hidden star formation and gas content in this new population. Our program will: (1) quantify the fraction of gas-rich, vigorously star-forming hosts, (2) characterize typical star formation rates and gas masses (including through stacking), and (3) provide initial dynamical mass constraints. We have constructed the largest spec-z LRD sample to date, from a dedicated search of literature, public, and internal resources, including the latest JWST surveys. This study will provide the community with the first comprehensive reference ALMA results for a wide variety of LRDs, offering invaluable insights into the rapid SMBH growth and early co-evolution with their host galaxies. | Lyman Break Galaxies (LBG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 2207 | 2013.1.00218.S | 12 | Spatially resolved 3 mm imaging line survey toward NGC 7469 | We propose to conduct a line survey toward the central kpc region of the nearby type-1 Seyfert galaxy, NGC 7469, at 3 mm wavelength. This observation will be combined with our accepted cycle 1 program toward the same region, to fully cover 86-116 GHz range. From this observation, we will investigate the effect of AGN and starburst activity on the molecular materials. For example, we focus on the abundance variation of (1) HCN and CN, which are expected to be enhanced in AGNs, (2) molecules sensitive to UV radiation such as HNCO, which can be used to probe the phase of starburst activity, and (3) dust-related molecules such as SO, CH3OH, SiO, CH3CN, to investigate their properties especially in AGNs. All observed properties will be compared with chemical models and results of our ALMA cycle 0/1 programs toward NGC 1097, 253, and 1068, to further investigate the effect of AGN and starburst on molecular properties. In addition, NGC 7469 hosts a bright type-1 AGN whose Eddington ratio is comparable to QSOs. Therefore, this observation can also serve as a local template of molecular properties for exploring high-redshift QSOs in future ALMA cycles. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2016-01-15T12:36:56.000 |
| 2208 | 2019.1.00315.S | 6 | The Bursting Massive Young Stellar Object S255 IR | Temporal photometric variations associated with young low-mass stars of Class 0, I, and II have been observed. It is conceivable that similar burst phenomena occur in the massive star formation process. Indeed, on the theoretical front, 3D numerical radiation hydrodynamic simulations yield variable accretion events in high mass star formation. Observational evidence in favour of episodic bursts in the high-mass domain also grows steadily in the recent years - two massive young stellar objects, S255IR SMA1/NIRS3 and NGC6334 I, exhibit submillimeter luminosity bursts. For further understanding the flaring events, it is indispensable is to take advantage of such rare objects at their unique varying phase with follow-up observations. To this end, we propose sensitive ALMA observations at Band 7 with two key science goals: (1) measuring its temporal variation in dust continuum and molecular line emission, and (2) imaging at the highest angular resolution the disk sub-structures (arms, clumps). With ALMA's exquisite sensitivity and resolution, the proposed program will in great detail characterize the burst history and reveal the underlying structure of the S255IR SMA1/NIRS3. | High-mass star formation | ISM and star formation | 2022-08-23T23:26:57.000 |
| 2209 | 2016.1.00372.S | 211 | Complete Census of Bright Lensed Submillimeter Galaxies Discovered by the Herschel Lensing Survey | To discover exceptionally bright cluster-lensed submillimeter galaxies (SMGs) like the Cosmic Eyelash, our team has been conducting a large Herschel survey of gravitationally lensed galaxies in the fields of massive galaxy clusters: The Herschel Lensing Survey (HLS) (PI: Egami). The HLS has obtained deep PACS (100/160 um) and SPIRE (250/350/500 um) images of 54 massive galaxy clusters as well as shallower (but nearly confusion-limited) SPIRE images of 527 clusters with a total observing time of ~420 hours. Now completed, the HLS has identified a number of exceptionally bright Herschel sources that are likely lensed SMGs at z>1. Here, we propose to obtain high-resolution (beam=0.2'') ALMA dust continuum images (at 1.3mm) of the 21 HLS sources, which represent the brightest of the sample. ALMA high-resolution images are essential for, (1) identifying the counterparts and lensing geometry, (2) examining the relation between the dust continuum sources and the stellar continuum sources detected at shorter wavelengths, and (3) probing the physical properties of individual star-forming regions at the sub-kpc scale through the reconstruction of the source-plane image. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-12-02T23:40:23.000 |
| 2210 | 2021.1.00024.S | 3053 | A Legacy Survey of SMGs in the CDF-S | We propose ALMA linescans for a complete sample of 51 S(850um)>2.25mJy SMGs from an extremely deep SCUBA-2 CDF-S map, all with accurate positions/fluxes from prior band 7 ALMA imaging. The scans will detect 2+ bright CO transitions in the majority of SMGs, establishing firm redshifts (unlocking great potential for individual and stacked spectral constraints from radio to X-ray), robust molecular gas (mass, excitation curves, kinematics, t_depl) and dust properties (mass, temperature) estimates. These precise physical constraints, which are unattainable by UV/opt/NIR methods, will advance our understanding of star formation in this critical flux regime, which accounts for 30% of the 850um background. The samples completeness and the unsurpassed ancillary data in the central CDF-S (deepest Chandra, Herschel, HST NIR/optical, and soon JWST) make it a unique legacy dataset for understanding typical SMGs. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-09-27T17:25:23.000 |
| 2211 | 2013.1.01397.S | 2 | Measuring Velocity Structure of MHD Wind from a Protoplanetary Disk | We propose to observe line transitions of CI, CN and 13CO at bands 7 and 8 with high velocity resolution and high sensitivity in order to measure velocity structure of the MHD wind from a protoplanetary disk around TW Hya. Recent MHD simulations suggest that angular momentum transfer and mass accretion in the disk surface will be induced by magnetocentrifugal wind rather than magnetorotational instability. Our observations of a disk wind will give us information on mass accretion mechanisms, which is essential to understand gas dispersal from the disk and then planet formation processes. The wind velocity is not easy to measure since it is small compared with the Keplerian rotation velocity. Here we propose to detect the disk wind velocity, using PDR species (CI and CN) as disk wind tracers and 13CO as a tracer of Keplerian rotation. The difference in the maps of intensity weighted velocity field between the lines give us clear evidence of the disk wind. In addition, the difference in the maps of intensity weighted velocity dispersion will show the radial distribution of wind velocity and give us information of how angular momentum transfer is controlled in the disk surface. | Disks around low-mass stars | Disks and planet formation | 2016-07-14T07:56:35.000 |
| 2212 | 2011.0.00957.S | 0 | The ALMA-SPT Redshift Survey | Recent ground and space-based multiwavength (sub)millimeter surveys covering hundreds of square degrees have discovered a large number of strongly lensed, ultra-bright submm galaxies (SMGs). The largest of these, by nearly an order of magnitude at present, is the South Pole Telescope (SPT) survey, which covers 1300 square degrees. The unparalleled SPT sky area makes it the survey most adept at locating the 'brightest of the brightest' of this new population. Its 1.4mm detection wavelength ensures a uniform source selection function across z=1-8. Both aspects make SPT the ideal survey to uncover substantial numbers of the elusive z>4 SMG population. We are carrying out a major multi-wavelength (optical to mm) observating campaign aimed at characterizing the SPT sources in terms dust/gas content, star-formation rates and stellar masses. The most urgently missing information are the redshifts. With the advent of ALMA, even in the early science configuration, unbiased redshift searches for these bright high-z sources are possible in a revolutionary small amount time (3-4 redshifts per hour even in moderate observing conditions). We propose to observe the 26 brightest SMGs selected from the SPT survey. Our proposed observations are designed to obtain unambiguous and unbiased redshifts out to z=6, and as such will sample the high redshift tail of SMGs for the first time. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2013-04-25T07:42:09.000 |
| 2213 | 2019.1.00092.S | 49 | What lines trace which processes in the CMZ? | The Central Molecular Zone (CMZ) of our Galaxy is bright in many lines that are usually limited to hot protostellar cores in other parts of the Galaxy. These abundant molecular lines may tell us a great deal about protostellar cores, outflows, shocks, and general gas properties, but at the moment, we do not know which lines are associated with different physical processes. A reference survey showing which lines are excited and where they are excited is needed to interpret existing CMZ observations, to plan future observations, and to enable comparison between our CMZ and the centers of other galaxies. We propose a blind, complete spectral line survey covering bands 3-7 of a single pointing in the CMZ to determine which lines can be used to trace: (1) protostellar cores, (2) turbulent shocks, (3) diffuse and quiescent molecular gas, and (4) protostellar outflows in the CMZ. We will run this program as a legacy survey, releasing data immediately, and we will produce data products that will inform ongoing and future CMZ programs. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-06-10T22:16:38.000 |
| 2214 | 2022.1.00968.S | 322 | Exception or the Rule? A Survey for Gas in Debris Disks | ALMA detections of gas-rich debris disks around A type stars of 10-50 Myr have led to a re-writing of our understanding of late disk evolution. Collisions between planetesimals in debris disks release a second generation of molecular gas that can have a transformative influence on the atmospheres of planets in the system. Although only found in around 20 objects so far, the detection rate of secondary gas in debris disks suggests that this is not an exceptional group, but rather the normal state for debris disks, particularly around A-type stars. We require a large survey to validate the proposed ubiquity of large amounts of molecular gas in systems that have evolved beyond the protoplanetary phase. We request a deep survey of gas and dust in the debris disks of A type stars in Lower Centarus Crux and Upper Centaurus Lupus (15-20 Myr). Our 46 targets + 10 archival objects comprise a nearby, complete sample that is ideal for detecting molecular gas in systems that have evolved from the protoplanetary- to debris- phase. These observations will determine how common this gas-rich phase is around A type debris disks and measure the typical disk masses with which they are present. | Debris disks | Disks and planet formation | 2023-10-28T10:56:24.000 |
| 2215 | 2018.1.01172.S | 8 | Measuring Magnetic Field Morphologies in Disks Using the GK Effect | Polarimetric observations and theoretical modeling indicate that we cannot measure the magnetic field morphology in circumstellar disks via (sub)millimeter polarization continuum observations. The Zeeman Effect is also very difficult to observe toward circumstellar disks, and does not provide the plane of sky field morphology. One other promising way to measure the magnetic field morphology in the plane of the sky is via line polarization. The Goldreich-Kylafis (GK) effect suggests that line polarization is perpendicular or parallel to magnetic field direction. We propose to observe line polarization toward the disks IM Lup and HD 142527. These observations will tell us whether the GK effect can measure the magnetic field morphology in disks. | Disks around low-mass stars | Disks and planet formation | 2020-12-12T14:34:09.000 |
| 2216 | 2017.1.01174.S | 248 | Directly linking gas and ice abundances in low-mass protostars | The main scientific goal of this proposal is to test observationally whether complex molecules detected in the gas phase originally have been formed by solid-state processes in icy grain mantles, as assumed in most interstellar chemistry models. Comparison of abundance ratios of these molecules obtained with ALMA in hot cores and envelopes with those derived from ice spectra to be obtained with JWST-MIRI GTO data for the same sources offers for the first time the opportunity to actively bridge the gas-grain gap. | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-02-12T13:12:23.000 |
| 2217 | 2011.0.00396.S | 0 | Using the first inteferometer H2D+ observations to constrain clustered star-forming core structure | Given that most stars in our galaxy form in clusters, understanding the process of clustered star formation has become a key goal of star formation astronomy. As a dense core collapses, however, the density progression and accompanying temperature changes result in well-documented molecular abundance variations. The consequences of this chemical evolution are twofold: first, we must select molecular tracers carefully for the conditions we are probing; and second, we can use detailed modeling of the structure, chemistry and kinematics of dense cores to determine their evolutionary history and predict their future. The molecular ion H2D+ is likely the best kinematic probe of the dense core gas most actively forming stars. Here, we propose to use the unprecedented sensitivity and resolution of ALMA to probe the kinematics and chemistry of two evolved, star-forming cores using H2D+ and N2H+ to determine observationally for the first time the H2D+ and N2H+ abundance structure across dense cores on scales of ~ 360 AU. Through detailed modeling, these data will provide much-needed constraints to dynamic chemical models of core collapse in clustered environments. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2013-11-21T16:16:00.000 |
| 2218 | 2015.1.01452.S | 197 | CO spectral scanning of z>6.5 QSO candidates selected from PanSTARRS | We propose ALMA spectroscopy of 23 QSO candidates at z>6.5 selected from the new PanSTARRS1 3pi survey. Our goal is to build a statistical sample of z> 6.5 QSOs, which is crucial for understanding of the reionization epoch and growth of the supermassive black holes in the early Universe. All targets are clear z-band dropouts (detectable only in the y band) with faint/no detection in WISE. This makes them very promising high-redshift QSO candidates. We propose a new and more efficient spectroscopic survey, by spectral scanning CO(6-5) emission in ALMA Band 3. The redshifted CO(6-5) line is between 84 and 92 GHz. Therefore, we only need two tunings to scan the CO line at 6.5 | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-03-29T15:42:11.000 |
| 2219 | 2024.1.01709.S | 0 | Multiplicity and dynamical properties in embedded massive star-forming clusters | The characterization of stellar multiplicity (frequency, separation, and mass distribution) is an important input to star formation theories. In the case of massive stars forming in distant dense and young clusters (< 3 Myrs), the lack of observations results in a gap regarding the evolution of the multiplicity fraction. This proposal requests high-angular resolution ALMA band-6 observations to study the multiplicity properties in four massive star-forming clusters in their near-primordial state. We wish to (i) search for (proto)binary/multiple system candidates, (ii) determine their intra-cluster and inter-cluster properties (e.g. separation, mass ratio) and how they scale with cluster properties, (iii) compare their spatial distribution with large-scale structures and properties. These observations will be compared to existing K-band data. The multi-wavelength approach proposed in this study will ensure the analysis of intra- and extra-cluster multiplicity evolution on timescales of less than 3Myrs, bringing new light on the onset and evolution of stellar multiplicity in clustered environments. | High-mass star formation | ISM and star formation | 2025-11-16T13:12:11.000 |
| 2220 | 2017.1.00930.S | 30 | Evolution of Molecular Gas Excitation from Starbursting to Quiescence | The bimodality of star-forming vs. quiescent galaxies is driven by a bimodality in gas content. Post-starburst galaxies are experiencing a transition from star-bursting to quiescence, not only in their stellar populations but also in their molecular gas properties. Our work has revealed that molecular gas can remain after a starburst has ended, with depletion occurring during the post-starburst phase. Our next step is to study when the excitation state of the gas changes from the high excitation states seen in starbursting galaxies to the low excitation state seen in quiescent early type galaxies. We propose to observe the CO (3--2) emission spatially resolved across four post-starburst galaxies, to determine if evolution in the CO spectral line energy distribution occurs before, during, or after the post-starburst phase. These results will inform how the gas depletion mechanism affects the state of the gas as it is depleted. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2019-12-06T17:53:55.000 |
| 2221 | 2021.1.00327.S | 60 | The ultimate test of AGN feedback at cosmic noon: deep ALMA observations tracing molecular outflows and halo heating | AGN feedback, in the form of massive outflows and halo heating, is regarded as the key phenomenon reponsible for quenching star formation in massive galaxies and resulting in the popultion of local passive, massive galaxies. Although AGN feedback has been investigated extensively in the local universe, the bulk of the quenching action is expected to happen at z~2. Only a few (often marginal) detections of AGN-driven molecular outflows have been obtained at high redshift, and only tentative detections of halo heating associated with AGN winds have been reported at high-z. We propose deep CO(3-2) and Band 3 continuum observations of a sample of AGN at z~2, representative of the dominant Black Hole accretion mode at this epoch, which have been already observed with ALMA and whose stacked spectrum shows indications of molecular outflows. The much deeper proposed observations will enable us to individually detect molecular outflows and also the SZ signal associated with putative halo heating generated by AGN winds. The results will enable us to directly test AGN feedback scenarios, and in particular the effectiveness of the ejective or delayed (halo heating/starvation) modes. | Outflows, jets, feedback | Active galaxies | 2022-11-10T21:50:46.000 |
| 2222 | 2022.1.00101.S | 136 | Heating and Cooling of the Interstellar Medium in Dusty Galaxies at Cosmic Noon | The transformation of molecular gas into stars is a function of how gas heats and cools, the details of which can be measured by ALMA. To study how stars form at the peak epoch of star formation, we select a sample of 13 dusty, infrared (IR) luminous z~1-2 galaxies, the likes of which dominate the cosmic star-formation rate density at z~1-3, on the basis of bright Polycyclic Aromatic Hydrocarbon (PAH) emission detected in their Spitzer spectra which is essential for measuring the gas heating. In this survey, we will obtain [C II] and dust-continuum observations to measure their gas cooling, IR sizes and ISM properties. These observations will provide the first solid link between [C II] and PAH luminosities at z>0, increasing the sample of galaxies at cosmic noon with measured heating and cooling diagnostics by an order of magnitude, and provide a connection to the overall properties of dusty star-formation, answering the question: Are the high star-formation rates in z~2 dusty, star-forming galaxies powered by simply more gas, or are the ISM conditions different in ways that enable more efficient star formation? | Starbursts, star formation | Active galaxies | 2023-12-21T16:27:08.000 |
| 2223 | 2015.1.00752.S | 5 | ALMA Unveils the Hierarchical Formation of Massive Galaxies | Our team has used ALMA continuum imaging from Cycle 0 and Cycle 2 to discover that wide-field Herschel and ASTE/AzTEC surveys can be used to uncover blends of multiple DSFGs with pairwise separations that are significantly smaller than what is found from ALMA follow-up of other single-dish surveys. Theoretical simulations have difficulty reproducing this population of multi-component and small-separation DSFGs, but they suggest that a portion of the population may be due to line-of-sight projection effects and are not physically related. We obtained CARMA and PdBI obsevations of CO(3-2) and CO(4-3) indicating this is not the case for one target, but a larger sample size is needed to push this test to the next level. We propose a redshift search for CO emission in 2 targets with four or more ALMA counterparts from our Cycle 0 program and CO imaging of 2 additional targets with 3 or more ALMA counterparts and a known redshift. The redshift search data are critically needed to test whether the ALMA counterparts are physically associated, and the CO kinematics are essential to inform theories of how stars form in these complex systems. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2017-08-21T05:58:03.000 |
| 2224 | 2016.1.01269.S | 69 | Stimulated AGN feedback in cluster cores | ALMA has revealed that radio AGN drive massive molecular gas flows in galaxies, and has identified a population of slowly moving molecular clouds in massive galaxies that are difficult to understand. Observation indicates these clouds were lifted from the nucleus by rising X-ray bubbles, or the clouds formed in the bubbles' updrafts. We propose to test this model using ALMA CO(3-2) and CO(1-0) observations of two brightest cluster galaxies harbouring powerful radio AGN, molecular gas masses exceeding ten billion solar masses, and star formation rates of up to 140 solar masses per year. The results will yield new and significant developments in our understanding of radio-mode feedback, which is common to all elliptical galaxies and may drive their evolution. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2017-10-27T19:35:48.000 |
| 2225 | 2017.1.00478.S | 252 | Feedback and Star Formation in Extremely Red Quasars | Dust-reddened quasars are candidate young objects participating in the early stages of massive galaxy formation. Our team recently discovered a unique population of high-redshift extremely red quasars (ERQs) in SDSS-III/BOSS that has an ensemble of peculiar line properties indicative of powerful outflows, e.g., strong blueshifted broad emission lines, frequent broad absorption lines, and the broadest most blueshifted [OIII] 5007 lines ever reported (reaching 5000 km/s). We propose Band 6 observations of 15 ERQs at redshifts ~2.4 to measure their CO(7-6) and [CI](2-1) emission lines and dust continua (at ~385 microns rest) at 0.63 resolution. Our goals are to 1) characterize the ERQ population compared to star-forming SMGs and other/normal quasars at similar redshifts, 2) test the youth of ERQs in quasar/galaxy evolution schemes, and 3) study the effects of their powerful outflows on the ISM and star formation in the host galaxies. We will specifically search for extended molecular gas/dust emissions or extreme line kinematics indicative of blowouts, and estimate molecular gas/dust masses, the fractions of molecular gas participating in star formation, and star formation rates. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-06-28T18:46:22.000 |
| 2226 | 2023.1.00154.S | 0 | Searching for volatile phosphorus at the epoch of planet formation | The potential habitability of planets depends on the availability of the fundamental elements for bio-chemistry at their time of formation. Phosphorus is of particular interest as it is essential for the synthesis of DNA. To date, current detections of P-bearing volatiles toward forming stars are associated with shocks. This supports the understanding that the bulk of the elemental reservoir of P is locked up in refractory materials. But, with the detection of volatile P in comet 67P it is unclear if there is actually a significant volatile reservoir of P locked up in ices. The search for volatile phosphorus in planet-forming disks is an important step in understanding the delivery of this bio-essential element to planets. Therefore, we propose to observe the primary P-carriers PO and PN in the planet-forming disk Oph-IRS48. In this system, there is clear evidence for the sublimation of ices traced by complex organic molecules. If volatile P molecules are present in this disk, they should also be sublimated into the gas phase. Our proposed observations will be the first to fill a key gap between star-forming regions and comets. | Intermediate-mass star formation | ISM and star formation | 2025-07-23T19:05:52.000 |
| 2227 | 2012.1.00844.S | 120 | CO redshifts of SPT sources | Recent ground and space-based multi wavelength (sub)millimeter surveys covering hundreds of square degrees have discovered a large number ofstrongly lensed, ultra-bright submm galaxies (SMGs). The largest of these, by nearly an order of magnitude at present, is the South Pole Telescope (SPT) survey, which covers 2500 square degrees. Its 1.4mm detection wavelength ensures a uniform source selection function across z=1-8. Both aspects make SPT the ideal survey to uncover substantial numbers of the elusive z>4 SMG population. We have been granted ALMA observing time in cycle 0 to perform unbiased redshift measurements in the 3mm band in 26 SPT source. This survey is a large success and yields 45 detected line features, 16 (>60%) redshifts at z>3 and two sources at z=5.7 which places them among the most distant SMGs known today. The resulting redshift distribution is almost flat between z=2.5-4.5, in contrast to experiments based on radio identified SMGs in the past with far reaching consequences for the obscured star formation rate density at high redshift. Here we ask to extend our extremely successful efforts to obtain molecular line based redshifts of the SPT sources. In this proposal we focus on a particularly deep part of the SPT-survey located at 23h LST from which we have selected a complete flux limited sample of 15 SMGs with S1.4mm>16mJy within a 15x15 deg^2 field (compared to S1.4mm>25mJy over 1300deg^2 in cycle 0). The broader range of lensed fluxes gives us the ability to investigate and correct for possible redshift biases in different regimes of lens magnification. Combined with the derived magnifications from our imaging project this sample will also help to construct intrinsic flux (and therefore luminosity) limited samples and will the statistics in our SMG redshift distribution to determine its shape in the critical redshift range z=2.5-4.5 more precisely. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-11-13T00:00:00.000 |
| 2228 | 2018.1.01171.S | 249 | An ACA Survey of Dense Gas Across, the Nearest, Brightest Southern Galaxy Disks | We propose to use the 7m+TP ACA to map high critical density 3mm lines (HCN, HCO+ and CS) across 11 nearby star-forming disk galaxies. We will measure the star formation rate per dense gas mass, the dense gas mass fraction, and how these quantities change as a function of environment within galaxies. Current measurements suggest both quantities vary, but galaxy-to-galaxy scatter and small number statistics limit our ability to understand these trends. Our targets overlap the PHANGS CO survey, which is characterizing the mean density, virial parameter, and Mach number of molecular clouds. This offers the unique opportunity to relate the dense gas mass fraction and star formation per unit dense gas mass to these molecular cloud properties, providing a strong test of theories in which the properties of molecular clouds set the amount and behavior of dense gas. Our proposed observations will double the current sample of galaxies with 3mm dense gas maps and triple the set where dense gas can be tied to molecular cloud properties. ALMA represents the only option to map these critical southern targets, and the ACA is ideal for this surface brightness-limited experiment. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2020-01-24T18:48:20.000 |
| 2229 | 2015.1.00502.S | 6 | Spatially resolving the circumstellar envelope of WISE J180956.27-330500.2, an object recently experienced an extreme mass ejection | This proposal aims to resolve the circumstellar envelope of WISE J180956.27-330500.2, an object with an extremely optically thick circumstellar envelope using the long-baseline mode. Since its discovery in 2012 as an object showing significant change of the infrared fluxes in the last 20 years, we have carried out an intensive follow-up observation in various wavelengths to reveal its nature. Our ALMA Cycle 1 observation have detected CO(3-2) and SiO(8-7) lines on top of the relatively strong continuum. The expansion velocity of the molecules is 70 km/s. These observation data do not correspond to any kinds of known objects, and the nature of WISE J1810 has not been identified. To estimate the distance to the object and the luminosity of the object, we propose a high-spatial resolution observation of WISE J1810. The expected size of the object is 40-70 mas, and the ALMA's long-baseline observation shall resolve it. The observation will be carried out primarily in CO(2-1) line and continuum in Band 6. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2017-01-29T13:42:28.000 |
| 2230 | 2018.1.01577.S | 33 | Searching for PAHs in the Red Rectangle | Polycyclic Aromatic Hydrocarbons (PAHs) are widely accepted as the carriers of the Aromatic Infrared Bands (AIBs), but an unambiguous identification of any specific interstellar PAH is still missing. Here we propose to close this gap and conduct a deep search for the high-J rotational transitions in corranulene (C20H10) - a symmetric, bowl-shape PAH molecule with a large dipole moment (2.07 D). Our selected target is Red Rectangle Nebula, a pre-planetary nebula which is the brightest source of AIBs in the sky and where a previous attempt to detect corranulene was unsuccessful due to limited sensitivity. | Astrochemistry | ISM and star formation | 2020-08-31T10:32:06.000 |
| 2231 | 2013.1.01051.S | 22 | A high-resolution band-7 continuum survey of SMGs in the field of five SZE-selected galaxy clusters. | We propose to obtain band-7 continuum mapping at ~1 arcsec spatial resolution for a sample of 39 submillimeter galaxies (SMGs) detected with LABOCA (~18"/beam) in the field of five galaxy clusters originally detected through their Sunyaev-Zel'dovich Effect decrement signals at 148 GHz. The selected targets have 870 micron (345 GHz) flux densities ranging from 3.7 to 36.9 mJy, but our current photometric accuracy is compromised by blending of point source and extended SZE emission, and plausibly of multiple fainter SMGs within a single LABOCA beam. To secure detection of all targets and their possible sub-components at the 4 sigma level, we require a point-source sensitivity of 0.3 mJy. To achieve this observational goal, we require a total observation time of 2.2 hours including overheads. | Gravitational lenses, Galaxy Clusters | Cosmology | 2016-04-10T19:11:56.000 |
| 2232 | 2018.1.00375.S | 57 | Sulfur chemistry in the transition zone of low-mass protoplanetary systems | Tracing the chemical evolution during the forming processes of Sun-like stars and planetary systems is crucial for understanding the origin of the Solar system. Our previous observations towards two protoplanetary systems (a Class 0 and a Class I) show significant chemical differentiation in their transition zones, i.e., the CS line traces the infalling-rotating envelope (200 AU), while the shock-enhanced SO line traces the centrifugal barrier (100 AU). Therefore, both sources are ideal laboratories to investigate the time-dependent sulfur chemistry. We propose to observe Band 5 lines of H2S, H2CS, SO2 and CCS towards both sources at a linear resolution of 70 AU. Incorporating our previous ALMA data and our well-developed gas-grain model, these observations will allow us to (1) image the sulfur grain reservoir H2S for the first time towards low-mass protoplanetary systems; (2) investigate the origin of the SO near the centrifugal barrier; (3) construct the gas temperature profile of each source from the ~1000 AU protostellar envelope down to the 70 AU transition zone; (4) draw a clear picture of the sulfur chemistry towards the transition zone in an evolutionary context. | Disks around low-mass stars | Disks and planet formation | 2020-09-11T15:36:54.000 |
| 2233 | 2013.1.01200.S | 30 | The mass-loss rates of Red Supergiants | The evolution of massive stars and the nature of supernova (SN) progenitors are highly sensitive to the amount of mass lost during a star's lifetime. Though much attention has been paid to the mass-loss rates of hot massive stars, the winds during the RSG phase have recieved relatively little attention, despite the fact that 10% of the envelope can be ejected during this short phase. The main reason for this is that most of the mass ejected is in the gas phase, but this material is difficult to detect - gas mass-loss rate measurements for even nearby RSGs have required several hours' integration with e.g. the JCMT. With ALMA, it is now possible for the first time to measure the gas mass-loss rates of large sample of RSGs. In this proposal we target a coeval cluster of RSGs, where all stars have roughly the same mass and chemical composition, with the only variable being how far along the RSG branch the stars are evolved. We will therefore be able to study how the mass-loss rates of RSGs increase with evolution, as their dusty envelopes become more opaque, and ultimately determine the total mass lost prior to SN - the key parameter in the appearance of the SN explosion. | Main sequence stars | Stars and stellar evolution | 2016-06-19T03:04:00.000 |
| 2234 | 2017.1.00190.S | 120 | Physics of the interstellar medium of galaxies in the reionization era: the [OIII]-to-[CII] line ratio II | We propose a continuation of our high priority program: the first systematic survey of the ratio of the [OIII] 88 micron line to the [CII] 158 micron line of bright galaxies at 6 | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-09-21T16:02:49.000 |
| 2235 | 2017.1.00908.S | 19 | The Molecular Gas and Dust Distribution of the Hot Dust Obscured Galaxy W0410-0913 | The WISE mission has recently identified a rare population of high-redshift, hyper-luminous infrared galaxies, all with bolometric luminosities above 10^13 L_Sun, and many exceeding 10^14 L_Sun. Characterized by their extremely red mid-IR colors and very hot dust temperatures, these hot, dust obscured galaxies (Hot DOGs) likely probe a key stage in the galaxy evolution paradigm. During cycles 2 and 3 we have carried out observations of the [CII] emission line which confirm these galaxies are in a cathartic stage. One of these Hot DOGs, W0410-0913, shows a very extended dust continuum and the highest [CII] deficit ever measured. We request here deep, high-resolution observations of the CO(6-5) emission line and the nearby dust continuum to study the physical state of its ISM. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2019-01-26T01:00:44.000 |
| 2236 | 2023.1.01431.S | 0 | Unveling the water content during planet formation | The water molecule has been a key ingredient in the emergence of life on our planet. It also plays a major role in planet formation as it can promote the formation of planetary cores, and govern the oxygen chemistry in both gas and ices during protoplanetary disk evolution. Motivated by the exciting discovery of distinct lines of the main H2O isotopologue in a planet forming disk with ALMA, we propose to characterize the water emission of the three protoplanetary disks with published methanol detections by ALMA. The selected disks present a diverse set of morphologies, chemical properties (C/O ratios) and stellar luminosities. With our observations, we will provide sorely needed constraints on the water vapour spatial distribution, on the snowline location, and on the correlation between water gas and mm continuum substructure in different environments. The requested data will also allow for the first direct constraints on the methanol-to-water ratio in Class II disks in distinct desorption regimes, and will be used to benchmark the proposed HCO+ - H2O anticorrelation to infer snowline locations. | Disks around low-mass stars | Disks and planet formation | 2025-07-16T07:21:35.000 |
| 2237 | 2019.1.00177.S | 10 | The dusty disk in the Red Rectangle | Disks rotating around post-AGB stars should play a fundamental role in the late stellar evolution, yet they remain poorly studied. Only a few post-AGB disks have been well mapped in CO emission, with resolutions of 0.2-0.5". The general structure of the gas-phase component was studied, but the dust mm-wave continuum emission was hardly resolved. In the best studied source, the Red Rectangle, the disk diameter in the continuum is ~ 2", with a dominant component of about 0.2" and a a disk width ~ 40-200 mas. Post-AGB disks have been also imaged in the NIR, which only probe the hottest dust emission in the disk inner rim, with diameters ~ 40 mas. We propose high-resolution continuum mapping in three ALMA bands of the Red Rectangle, whose disk is extended and seen edge-on; some strong lines will be simultaneously observed to better compare the gasoues and dusty components. ALMA can accurately map those emissions with 15-30 mas resolution. Such data will reveal features relevant to understand the nature and evolution of post-AGB disks, like the disk width and flaring, the latitude stratification of the grain temperature and size, and the molecule depletion in the central disk regions. | Post-AGB stars | Stars and stellar evolution | 2022-10-21T17:15:19.000 |
| 2238 | 2017.1.01694.S | 78 | A dense molecular gas survey at high redshift | The properties of the dense molecular gas (which traces the places where star formation takes place) have been largely studied in the local Universe. However, only a few studies have aimed at understanding the dense molecular gas at high redshift, most of them based on AGNs and QSOs. Building up on the results from a previous ALMA pilot project (Oteo et al. 2017), we here propose to carry out a dense molecular gas survey by targeting the J=4-3 HCN, HCO+ and HNC transitions in a statistically-significant sample of 17 star-forming-dominated, lensed (U)LIRGs at 1.3 < z < 3.3 selected from the H-ATLAS survey. This is the full sample of lensed high-redshift SMGs from H-ATLAS that can be observed in the same J->J-1 transitions, and arguably the best sample to do the proposed studies (unlensed high-z samples would require very long integration times). Combined with previous data (including CO, [CI], [CII] and water transitions), the proposed observations will allow us to carry out the first systematic study of the dense molecular gas and the properties of star formation at high redshift. | Surveys of galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2019-04-30T20:51:20.000 |
| 2239 | 2012.1.00139.S | 50 | Nuclear Continuum Spectra of nearby low-luminosity AGNs | We propose point source photometry for ten nearby low-luminosity AGNs at ten frequencies in the band-3, 6, and 7 to obtain continuum spectra for understanding accretion and outflow phenomena in scales of about 10 Schwarzschild radius, in advance of a future submm VLBI. The execution time is 1.3 hr in total. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2017-01-29T19:48:31.000 |
| 2240 | 2018.1.00500.S | 64 | Testing the Cometary Origin Scenario in a Young, Gas-bearing, Beta Pictoris Analogue | Comets in the young Solar System played a key role in the delivery of volatiles, including water, into the Earth's young atmosphere. At least 3 debris disk systems, including the archetype beta Pic, exhibit confirmed evidence for gas production via cometary activity. Models of their gas can provide important clues on the volatile composition of exocomets, and by inference on the atmospheres of the exoplanets they will enrich. The archetype beta Pictoris debris stands out as the best studied debris disk system with exocometary gas. We have developed a model that can consistently explain its low gas mass and dust luminosities in the frame of colliding, volatile-rich bodies. Can this model explain the origin of gas found in other debris disk systems ? We have recently discovered a young debris disk, that harbours beta Pic-like amounts of dust and gas in mm emission, as well as variable circumstellar absorption in the optical, strongly suggesting that exocometary activity is ongoing. We propose to acquire Bands 6 & 7 images of the dust and gas at 0.2 arcsec resolution to obtain key diagnostics needed to constrain the general case of the exocometary origin of the gas. | Debris disks | Disks and planet formation | 2020-10-03T03:29:01.000 |
| 2241 | 2016.1.00050.S | 2 | Solar Chromospheric Heating | We aim to constrain the heating mechanisms in both the quiet solar chromosphere and the plage chromosphere by obtaining coordinated ALMA and IRIS observations and comparing those with synthetic observations of advanced numerical models of the chromosphere. The dominant heating mechanisms in the solar chromosphere remain poorly known, in part because of the complex diagnostics that are often difficult to interpret. The availability of ALMA observations, with their linear dependence on temperature, combined with IRIS observations of Mg II h and k lines promises to provide new insights into the coolest parts of the chromosphere and the magnetically dominated chromosphere in plage. In particular we will focus on understanding the importance of the interactions between ions and neutrals and the ambipolar diffusion resulting from these interactions which dissipates magnetic energy and which our models predict plays an important role in the energy balance of both regions. We will use two time series with one pointing that includes internetwork and plage of 1 hour long, one in band 3 and one in band 6, in coordination with IRIS and Hinode/SP observations to address our science goals. | The Sun | Sun | 2018-07-05T00:00:00.000 |
| 2242 | 2022.1.00638.S | 199 | Dust evolution in planet-forming disks: from early stages to the end of disk lifetime | Planet formation takes place in disks of gas and dust that orbit young stars. The fundamental question of how disk constituents - the gas and solids - evolve with time is yet unanswered, but the ongoing ALMA Large Program AGE-PRO was designed to answer this question for the gas component. However, constraints derived on the dust constituent from these observations will be much limited. Thus, we propose to obtain ALMA multi-wavelength continuum observations for the full AGE-PRO sample at 2.9 and 1.8 mm, to establish how the solid component in disks evolves with time and to compare with dust trapping and radial drift models. We will constrain properties of solids (mass, temperature, size distribution, albedos, etc.) and dynamical parameters (gas-to-dust ratio, Stokes number, Toomre parameter), and infer how dust evolution and dust properties change radially for each disk. These new measurements, coupled with the extensive knowledge to be derived for the sample in the gas, will allow for a complete picture of how gas and solids evolve for the different evolutionary phases investigated: the embedded disk phase, the middle-age, and the end of the disk lifetime. | Disks around low-mass stars | Disks and planet formation | 2024-07-14T16:42:32.000 |
| 2243 | 2018.1.01115.S | 1915 | A Large Unbiased and Complete Survey of CO in the Small Magellanic Cloud | The Small Magellanic Cloud (SMC) is the only laboratory to study the low metallicity ISM at high spatial resolution, and yet we still do not know where the CO emission exists. We propose to use the ACA in standalone mode to map a 1.0 x 0.5 degree (1 kpc x 500 pc) region of the SW Bar of the SMC in 12CO, 13CO, C18O (2-1) covering a large fraction of the recent star formation, dust, and HI gas. With this new map we will be able to catalog CO clouds and clumps down to a mass of ~1000 solar masses and with a factor of ~15x increase in luminosity sensitivity over the existing large-scale single-dish APEX map. With only the ACA and the minimum integration time per pointing, we will produce a map of extragalactic CO with the greatest mass sensitivity and covering ~1.5 pc to 1 kpc scales. Once we have an accurate account of the CO-emitting gas we will be able to measure the CO luminosity function, the dynamical state, how CO brightness relates to environmental properties, and variations in X(CO). Further analysis of the data will allow us to understand the turbulence properties across all scales and how the CO emission relates to the HI gas at low metallicity. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2019-11-29T10:54:39.000 |
| 2244 | 2018.1.01833.S | 117 | The disks around low-mass stars in the solar neirborhood | Debris disks are signposts of successful planet formation in some stars. Several years of studies have revealed a broad population of evolved disks. This population shows a clear decrement in the frequency of disks towards later spectral type stars. The origin of this trend is not clear, but evidence suggests there is a segregated evolutionary path that might depend on the stellar mass/temperature. M-stars are the most abundant stellar objects in the Galaxy but the fraction of M-stars harboring warm debris disk seems to be very low, while complete surveys looking for the cold debris disks are not complete yet. Here we propose to observe a small sample of M-stars in the Solar neighborhood, all showing clear signs of harboring circumstellar material. We will use the ACA standalone to detect the cold component of debris disks around nearby M-stars, in order to determine the amount of dusty material present around the dwarfs and, this way, to constrain the formation and evolution of the very close M-stars population. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2020-09-08T16:22:13.000 |
| 2245 | 2021.1.01603.S | 6 | Sub-kpc mapping of the [CII]/dust in the highest-redshift ULIRG at z=7.3 | Recent studies have revealed the existence of particularly massive galaxies within the first Gyr after the Big Bang. These galaxies push the limits of galaxy evolution models, but detailed physical studies have been limited due to a lack of bright, spectroscopically-confirmed targets. Excitingly, ALMA has now discovered a massive (M_*=1.3x10^10 Msol), extremely [CII]- and IR-luminous galaxy (L_[CII]=2.0x10^9 Lsol, L_IR=1.1x10^12 Lsol) at z=7.3 -- the highest-redshift ULIRG known to-date. This exceptional source shows a clear [CII] velocity gradient, a clumpy UV morphology, and a possible outflow/companion, but the current ALMA data are too low-resolution to determine the mechanism(s) powering its extreme IR luminosity or how it is building its stellar mass. We propose sub-kpc (0.15/780pc) imaging of the [CII] and dust continuum in order to reveal the morphology and kinematics of the gas and dusty star formation. Together with the existing HST imaging and approved JWST NIRSpec/IFU imaging -- which will map the unobscured stellar emission on similar scales -- the proposed observations will provide an unprecedented view of massive galaxy formation just 700Myr after the Big Bang. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-09-09T00:00:00.000 |
| 2246 | 2015.1.01316.S | 10 | Search for an Intermediate Mass Black Hole in Ultra-luminous X-ray Sources | If intermediate mass black holes (IMBHs) with ~1000 Msolar exist or not is one of the biggest questions in the modern astrophysics. Ultra-luminous X-ray Sources (ULX) are bright compact X-ray sources often found in nearby spiral galaxies. Because their luminosities (10^40-10^42 erg/s) largely exceed the Eddington limits of the Galactic compact objects (10^38 to 10^39 erg/s), ULXs are prime candidates of the IMBHs. Alternatively, they may be massive stellar black holes (< 30 Msolar) shining at super-Eddington luminosities. Unfortunatelly, X-ray observations may not distinguish the two cases. Here, we propose a novel method to constrain the black hole mass in ULXs by measuring the position-velocity (PV) map of the Giant Molecular Clouds (GMCs) surrounding the ULXs. We propose to observe NGC 5408 X-1, which is known to be associated with optical and radio nebulae. If there is a 1000 Msolar black hole in the center, we will see a significant increase of the rotational velocity of the GMC toward the central black hole. This is measurable with the Cycle 3 nominal performance, and the cases with ~1000 Msolar black hole and ~30 Msolar black hole are clearly distinguished. | Black holes | Stars and stellar evolution | 2017-11-22T04:53:30.000 |
| 2247 | 2019.1.00843.S | 143 | The effects of feedback on molecular gas: Survey of CO in 30 Doradus | We propose a molecular gas survey of the 30 Doradus region to understand how massive star feedback affects the physics of star formation in the neighboring molecular gas. Our survey covers the most prominent CO-emitting regions within 60pc of the the R136 super star cluster. Abundant ancillary data makes 30 Dor the best studied case of extreme star formation at reduced metallicity, which may dominate star formation processes at higher redshift. The pre-main sequence (PMS) stars from our HST studies and the young stellar objects (YSOs) from our Spitzer and Herschel studies provide a ~2" map of star formation activity spanning the stellar initial mass range. With ALMA, we will map molecular gas with 12CO, 13CO, C18O J=2-1 and H2CO at a comparable angular resolution of ~1.8", to (1) measure the effect of the feedback environment on star formation triggering, activity, and thresholds, and (2) measure the degree to which feedback energy is directly transmitted into the turbulence of the molecular clouds. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2021-03-20T17:37:22.000 |
| 2248 | 2021.1.00576.S | 23 | Pushing the frontier with ALMA: star formation at sub-kpc scale in distant radio-loud AGN hosts | Powerful AGN near Cosmic Noon are tracers of active AGN feedback and massive galaxy formation. In particular, the population of high-redshift radio galaxies (HzRG) are the only objects in which quasar-mode feedback, radio-mode feedback and an active massive galaxy build can be observed simultaneously. We will use ALMA to observe the [CII] line + dust continuum in a sample of HzRG at z~3.5, tracing at sub-kpc scales both the young stellar population and cold gas. The sample has exquisite supporting data with MUSE, SINFONI, Spitzer, Herschel and has been approved for JWST Cycle 1. Despite this wealth of supporting data, the questions of how and where these massive galaxies form their stars and how the powerful AGN is triggered remain. At a resolution of 0.1arcsec with ALMA, we will map the cold dust distribution, informing us how star formation is connected to the AGN- and jet-driven outflows. The [CII] kinematics will enable us to disentangle outflows/mergers signatures and relate it to the ionised gas kinematics from JWST data. We will address the long-standing question how AGN activity, massive galaxy build-up, merger activity and environment are connected at and near Cosmic Noon. | Active Galactic Nuclei (AGN)/Quasars (QSO), Early-type galaxies | Active galaxies | 2023-12-19T14:02:17.000 |
| 2249 | 2018.1.00656.S | 10 | Radio-mode feedback at the highest redshifts: ALMA/VLBA synergistic observations of the brightest radio source at z~6 | Radio-mode feedback is a key ingredient in current formation theories of massive galaxies. The interactions between radio jets and the interstellar medium are thought to have a defining role for the co-evolution of the central supermassive black holes and galactic stellar masses. However, observational constraints on these feedback processes are still very limited or almost non existent beyond z>1, where theoretical galaxy formation models can be best constrained. We recently discovered a quasar that is the brightest radio source known at z~6 (by an order of magnitude). VLBA DDT observations (at 0.02"/120pc resolution) revealed a morphology similar to a radio galaxy with a total extent of 1.8kpc (0.3"). Here we propose ALMA matched-VLBA-resolution observations of the dust continuum and [CII] emission to study the interstellar medium of the only z~6 quasar known with evidence of powerful jets. This dataset will allow us to test whether the dust and gas in the host galaxy are affected by the ejected radio lobes. We will search for direct evidence for radio-mode feedback as an important process during the formation of a massive galaxy within the first billion years of the universe. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2021-02-07T16:58:17.000 |
| 2250 | 2015.A.00019.S | 9 | ALMA observations of a possible counterpart to the high-energy neutrino event IceCube 160427A | We propose for Directors Discretionary Time to search for millimeter emission from a recently discovered Type 1c supernova that appears to be a source of neutrinos but is quenched in gamma- and X-rays. Such objects, never before seen, are a possible source of the mysterious high-energy neutrino background. These ALMA observations, in tandem with the VLA and other resources, will provide essential information on the physical nature of the source and are time critical. | Gamma Ray Bursts (GRB) | Cosmology | 2017-01-21T20:47:30.000 |
| 2251 | 2019.1.00019.S | 44 | Measuring Central Black Hole Masses in Low-mass Galaxies | We observed seven nearby (D<20 Mpc) low-mass (M* < 10 billion solar masses) galaxies in ALMA Cycle-5 to enable more robust detections and dynamical mass measurements of ~10^6 Msun mass central black holes. These measurements will provide constraints on the formation of black holes in the early universe, and on the physics underlying galaxy-black hole scaling relations. Our target galaxies were chosen across the Hubble sequence and based on the presence of molecular gas from single dish surveys. The high-resolution observations of ALMA clearly detected evidence of nuclear rotating molecular disks, which are so called circumnuclear gas disks (CNDs), surrounding their black holes of five targets, and two of them are of sufficient quality to measure their black hole masses. In two other galaxies, the detected gas was not in rotating disks, necessary to derive black hole masses. For the last three galaxies, unfortunately, we are lacking short baselines in the data obtained. Here we propose to use ALMA to obtain intermediate resolution observations of these three targets. A small amount of additional time is needed to maximize the already invested ALMA time. | Galactic centres/nuclei | Active galaxies | 2021-01-26T14:55:10.000 |
| 2252 | 2013.1.00116.S | 0 | How Strongly are the 2 Known Class 0 Disks Magnetized? | To date only 2 Class 0 objects have well detected, ~100 AU Keplerian circumstellar disks: L1527 and VLA 1623. Other sources with similar or better resolution observations do not exhibit clear Keplerian disks, e.g. L1157, down to 10 AU scale. What is the difference in these two populations? Although a very small sample so far, there is an interesting trend. The sources with 100 AU disks have inferred magnetic fields nearly perpendicular to their disk rotation axis, and the sources without detected 100 AU disks have magnetic fields nearly aligned with their outflow axis (a proxy for the rotation axis). This is suggested by many current theoretical simulations as magnetic braking reduces the angular momentum of material falling onto the disk, resulting in a smaller circumstellar disk: 10 AU or less compared to 100 AU. In this proposal, we request time to measure the dust continuum polarization in the 2 known 100 AU Class 0 disk systems at a resolution of 50 AU. With the ability to constrain the inferred morphology and magnetic field strength in the systems, we will make better theoretical models to investigate magnetic braking and the early disk formation and evolution. | Disks around low-mass stars | Disks and planet formation | 2017-01-25T22:32:32.000 |
| 2253 | 2018.1.00781.S | 29 | A magnified view of the cradle of globular clusters at z>6 | We propose deep ALMA observations of the central, strongly magnified central multi-image of a giant Ly-alpha nebula which contains two globular cluster precursors (GCPs) at redshift >6. We will detect the 2P3/2-2P1/2 [CII] transition, one dominant neutral gas coolant. The systems embedded within the nebula are among the faintest spectroscopically confirmed star-forming sources at high redshift, have typical instrinsic sizes of 10-20 pc, UV magnitudes >~30 and SFR surface densities greater than 300 Msun/yr/kpc^2. Through band 6 observations with 0.5" FWHM resolution (probing delensed ~200 pc at z~6), we aim at tracing the distribution of the neutral gas in (and around) the two compact systems. According to our estimates, ~3 hr of ALMA time will be enough to detect [CII] and to: 1) assess the morphology of the neutral gas distribution around the two clusters. Coupled to extant Ly-alpha data, this will allow us to establish the presence of the cold gas which fuels star formation; 2) constrain the gas consumption timescale and, therefore, the duration of the SF event of our objects. Such pieces of information will open a new path to multiwavength studies of GCPs at high z. | Lyman Alpha Emitters/Blobs (LAE/LAB), Gravitational lenses | Galaxy evolution | 2020-09-04T11:47:32.000 |
| 2254 | 2012.1.00046.S | 1 | First Direct Measurement of Disk Radius of a Young Brown Dwarf | Up to now, more than 1,000 nearby brown dwarfs have been discovered and our understanding of physical properties of brown dwarfs has greatly been improved. The disk radius of young brown dwarfs is a fundamental parameter to study their formation mechanism as well as the onset of planet formation around these objects. A lot of work on disk modeling has been done to estimate disk radii of young brown dwarfs, however no direct measurement of disk radius of any brown dwarfs has been carried out so far. In this proposal, we propose to directly measure the disk radius of ISO-Oph 102, a young brown dwarf of 60 Jupiter mass in rho Ophiuchi. | Outflows, jets and ionized winds | ISM and star formation | 2015-09-16T19:22:38.000 |
| 2255 | 2016.1.01338.S | 81 | Flowing the gas from molecular clouds to protostellar envelopes | The formation and evolution of cores and envelopes (and the disks and protostars inside) depend on the density and velocity structure of their parent cloud or filament. The scales of the outer envelope/core (~10^4 AU) are particularly important as the gas properties on these scales influence the mass reservoir (and final mass) of the forming star, and the number of companions in a multiple system. We propose to conduct mosaic observations of a very young mini-cluster in a filament in Orion, representative of the way most stars form in our Galaxy. We will map the cluster using molecular lines that probe different regimes in the star formation environment in order to: 1) characterize the dynamical state and structure of the gas in a region of clustered star formation in a filament; 2) follow the kinematics and distribution of the gas from cloud to envelope scales (~0.1 pc to 1000 AU) in a cluster and study how these impact the multiplicity and disk properties of protostellar systems; 3) investigate how the feedback and gravity of a source affect nearby sources and the cluster medium; and 4) determine how these properties vary between sources at different ages within the cluster. | Low-mass star formation | ISM and star formation | 2018-10-06T15:36:47.000 |
| 2256 | 2015.1.00615.S | 39 | Revealing the disk rotation curve around an O-type YSO | Searching for massive rotating disks around early B-type and O-type young stellar objects (YSOs) is a key study to asses the main physical processes of massive star formation. Here, we propose to characterize for the first time the gas dynamics around an O-type YSO, unveiling the presence of a massive disk and determining its rotation curve, by means of high-resolution (0.2") and sensitive ALMA observations in Band 6 toward G23.01-00.41. This star forming site harbors a known hot molecular core (HMC) that we have recently studied in detail through both, SMA observations in the 230 GHz band (with an angular resolution of ca. 1"), and with VLBI multi-epoch observations of strong water and methanol masers. The outcome of these studies has unveiled a massive and flattened HMC, rotating about an O-type YSO with a dynamical mass of 19 Msun, which powers a well-collimated bipolar outflow at the sub-parsec scale. With this is mind, we want to observe the CH3CN(12_K-11_K) line emission and dust continuum at 1 mm to accurately trace the velocity field of hot and dense gas inside the HMC and to study the spatial morphology of both gas and dust emission. | Disks around high-mass stars | Disks and planet formation | 2018-01-28T13:57:40.000 |
| 2257 | 2016.1.00004.S | 5 | Resolving extended atmospheres of evolved stars: chromospheres and convection | Although processes like stellar activity and convenction can have a major impact on the circumstellar chemistry and chemical yields of evolved stars, the surface and extended atmosphere studies of these stars have so far been limited to the visual to near-infrared wavelength ranges, with limited imaging capabilities, or the marginal resolving power offered at radio wavelengths. Using ALMA long baselines, we have been able to resolve the details of the stellar atmosphere of Mira. This has demonstrated the unique capability of ALMA to study the surface structure and activity of AGB stars. Here we propose to map the stellar disk structure of four of the closest AGB stars in order to map their extended atmospheres and determine the presence of magnetic or convective activity at unprecedented resolution. Such observations, possible now for the first time, are crucial for modeling the structure of AGB atmospheres from radio- to optical wavelengths. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2018-12-07T20:27:48.000 |
| 2258 | 2024.1.00671.S | 0 | High-velocity Dispersion Compact Clouds Harboring Radio-Loud Black Hole Candidates | The central molecular zone of our Galaxy is populated by numerous high-velocity dispersion compact clouds (HVCCs). Some HVCCs exhibit clear rotational motions, suggesting the presence of intermediate-mass black holes (IMBHs). However, the absence of corresponding emission counterparts complicates understanding the driving mechanisms for HVCCs. The recent MeerKAT 1.28 GHz image revealed two point-like radio counterparts, potentially innovating our understanding of HVCCs. One source is non-thermal and exhibits a slightly elongated structure, indicative of a radio jet from an accreting black hole. The high-velocity dispersions around these sources may stem from jet-ISM interactions or gravitational accelerations by IMBHs. We propose spectral line and continuum observations of these HVCCs and their radio counterparts in ALMA Bands 1 and 3. By revealing the internal kinematics and the physical/chemical conditions, we aim to uncover the interactions between the radio sources and their surrounding gas. This project will not only shed light on the origins of the enigmatic molecular features, but could bridge the missing link between stellar-mass and supermassive black holes. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 3000-01-01T00:00:00.000 |
| 2259 | 2017.1.00856.S | 32 | [CI] as a gas tracer in main sequence star-forming galaxies at z~2 | Most of our knowledge about the gas content of galaxies in the early Universe comes from observations of the traditational tracer molecule, 12CO. However, there are several reasons to expect that 12CO is a very inefficient gas tracer in the star-forming, metal-poor environments within the ISM of high-z galaxies, which may have led to the gas content of high-z galaxies being systematically underestimated. We propose to observe the [CI](^3P1 - ^3P0) fine structure line (rest frequency 492 GHz) in a sample of seven main-sequence star-forming galaxies at z~2. This line is a more effective tracer of the cold molecular ISM, which is free of many of the biases that affect traditional gas tracers (i.e., 12CO). While observations of [CI] as a gas tracer to date have been promising, most galaxies observed in [CI] are extreme starburst galaxies not representative of the star-forming population as a whole. Our proposed observations of [CI] in a sample of 'normal' star-forming galaxies at cosmic noon are a vital first step in developing our understanding of [CI] as an improved tracer of gas in the early Universe. | Surveys of galaxies | Galaxy evolution | 2019-07-11T16:29:07.000 |
| 2260 | 2019.2.00129.S | 10 | Assessing the impact of AGN feedback in the prototypical Seyfert 2 galaxy NGC 1068 | NGC 1068 is the prototype of Seyfert 2 galaxies and one of the best-studied galaxies in the local Universe. High-resolution ALMA mapping of the central kpc has revealed strong AGN feedback effects, including a molecular gas outflow out to R~400pc. However, optical observations clearly demonstrate that AGN feedback extends further out, with two prominent ionisation cones that graze the disc and reach scales of 10 kpc. We propose to map CO(2-1) at 5.7" ~ 400pc resolution across the disc of NGC 1068 to measure the large-scale impact of the AGN. We will study whether molecular gas properties change inside the ionisation cones with respect to the rest of the disc and relative to other non-active galaxies. Combining with existing sub-arcsecond ALMA data, we will construct a high-resolution cube of the central area which is sensitive to all spatial scales, bridging the gap between AGN effects in the nuclear region and surroundings. | Outflows, jets, feedback, Giant Molecular Clouds (GMC) properties | Active galaxies | 2021-04-04T16:10:27.000 |
| 2261 | 2016.1.00248.S | 32 | Are Sub-virial Cores in IRDC G28.34 Supported by Magnetic Fields? | Massive stars form mostly in parsec-scale molecular clumps that collapse and fragment to spawn a cluster of stars. The current scenarios of massive star formation range from a relatively slow formation in which massive cores evolve in a quasi-static equilibrium supported by turbulence and magnetic fields, to fast formation in which clouds collapse in one dynamic time. The two scenarios can be examined through detailed equilibrium analysis including gravity, turbulence and magnetic fields. We propose to obtain dust polarization of three infrared-dark-cloud clumps G28.34 MM1/MM4/MM9 to investigate magnetic support in dense cores. The three clumps contain 500 - 1000 Msun each, sufficient to form massive stars, and show significant fragmentation when observed with the SMA and ALMA. Analysis found that the mass in the clumps and cores far exceeds their respective virial mass from turbulence. This ALMA observation will map the magnetic field configuration and determine magnetic field strength using statistics methods. Such a study can only be carried out with ALMA thanks to its sensitivity, and is vital to developing theoretical models on massive star formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-06-28T14:44:10.000 |
| 2262 | 2017.1.00053.S | 30 | Are Close Binaries Formed Through Disk Fragmentation? | Binary and multiple star formation is a common outcome of the star formation process, likely occuring at early times. To characterize the multiplicity frequency versus separation, we have conducted a VLA 8mm survey of all protostars (N~80) in the Perseus molecular cloud (d=230pc) at 0.065" (15 AU) resolution, identifying 18 proto-binary systems with separations between 18.5 and 440 AU. However, the VLA data alone do not directly constrain the formation scenarios of these close multiples, which are likely either disk fragmentation or turbulent fragmentation with dynamical evolution. We can discern between disk and turbulent fragmentation by characterizing the environments around the multiple systems. Therefore, we propose for ALMA observations of dust continuum and molecular line emission in C18O, 13CO, and 12CO toward 12 of the 18 close multiples. With these observations, we will identify rotationally-supported circumbinary disks, aligned or misaligned outflows, and relative source velocities that will reveal the origins of these systems. This sample is large enough to reveal whether or not close multiples typically form via disk fragmentation or turbulent fragmentation. | Low-mass star formation | ISM and star formation | 2019-12-12T19:04:01.000 |
| 2263 | 2024.1.00099.S | 0 | Calibrating [CII] as a cold gas tracer in high-z quiescent galaxies | How do galaxies quench in the early Universe? Whether quenching requires extreme gas depletion (e.g. via extreme AGN feedback or gas consumption) is not established yet due to the limited number of studies targeting dust continuum, CO(1-0)/(2-1)/(3-2) or [CI] in quiescent galaxies (QGs) up to z~3 with almost no individual detection. Critically, such tracers become increasingly less suited to explore the high-z Universe due to the unpractical time investment required to probe the ISM in high-z QGs at depths useful to reject bulge growth as a gas stabilisation method. Here we propose to probe the level of [CII] 158 micron line emission in the only 4 intermediate-z QGs previously detected in dust continuum or CO that are observable by ALMA at a reasonable sky transmission. With 15h in ALMA bands 9 and 10 we will provide a reference for the calibration of the [CII]-to-H2 conversion factor, bridging the gap between low-z and high-z QGs. We stress the critical value of such observations for the whole community in view of an extensive use of such gas tracer in high-z QGs in the next future, being the brightest and most efficient tracer to explore the gaseous component of QGs up to z=6. | Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 2264 | 2016.1.00627.S | 16 | Chemical evolution during the disk life cycle | The volatile compositions of planets, including water and organic reservoirs, are set by ice and gas compositions in protoplanetary disks. These compositions evolve with time due to a combination of time dependent chemistry and sequential lock-up of elements into icy boulders. As a consequence, the division of O, C and N between ice and gas may change dramatically between disk formation in embedded protostars and the time of disk gas dispersal ~5Myrs later. We propose to explore the time dependent disk chemistry, including the sequential removal of O, C, and N from the gas, through a systematic survey of O, C and N bearing molecules in 15 disks of different ages. The disk sample is drawn from nearby star forming regions Serpens, Taurus and Upper Sco, and contain protostellar disks, young and old protoplanetary disks. The survey will directly address the prevalence of substantial volatile depletion during planet formation, and at what timescales different elements are sequestered out of the gas-phase and into icy solids. The survey will thus provide initial conditions for planet formation throughout the lifetimes of protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2018-03-01T02:50:11.000 |
| 2265 | 2019.1.00151.S | 14 | Molecular and atomic gas in a z=2.5 X-ray cluster: examining star formation and environment in the early universe | We will undertake a case study of molecular and atomic gas in the most distant X-ray cluster core known at z=2.5. With a single pointing and two spectral tunings, we will detect 34 lines including neutral carbon, CO, and H2O in seven core member galaxies, along with Rayleigh-Jeans dust continuum. Combined with previous low-J CO observations, these will allow us to estimate star formation densities, calibrate alphaCO, look for the influence of shocks in gas heating, and, more broadly, compare gas conditions within these early universe cluster core galaxies to conditions in more familiar local systems. The results will yield insight into the fate of these galaxies and the effects of the cluster environment at z~2.5. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2021-06-23T16:23:49.000 |
| 2266 | 2018.1.01506.S | 48 | Characterizing the shocks in NGC 1068 | We propose to map the circumnuclear disk (CND) of NGC1068 in 3 lines of HNCO at a resolution of 0.5". The molecular gas in the CND is outflowing. The outflow is likely launched by the interaction of the AGN wind with the molecular gas in the disk; the interaction produces large scale shocks. In a recent paper, we compare the distribution of two shock tracers, SiO and HNCO, in the CND using PdBI observations. We find clear evidence of differentiation, with SiO and HNCO peaking in different locations. Our chemical analysis leads of the conclusion that high SiO and low HNCO indicate a fast shock, while high HNCO and low SiO indicates either a slow shock or just the presence of warm, dense, non-shocked gas. Hence while our study showed, without doubt, the presence of shocked regions within the CND, and also of different types of shocks, we can not, without higher spatial resolution, higher sensitivity and multiple transitions of both SiO and HNCO, determine the origin of the shock(s), their location and gas temperatures. Our team already has multiple SiO lines at the right resolution and sensitivity. In this proposal we ask for the equivalent information for HNCO. | Spiral galaxies | Local Universe | 2022-09-16T12:17:00.000 |
| 2267 | 2016.1.01504.S | 24 | Characterising the disk & collimated outflow from a high-mass protostar using multi-wavelength interferometry | In spite of its importance for astrophysics, the process through which massive stars form is only poorly understood. VLTI near- and mid-infrared interferometry by our team allowed us to resolve the AU-scale circumstellar environment around the high-mass (20 M_sun) YSO IRAS13481-6124, revealing a hot compact accretion disk around this object. Perpendicular to the disk plane, we detect a molecular outflow and two bow shocks, suggesting the presence of a collimated bipolar jet. Here, we propose ALMA Band 7 observations that will allow us to resolve the disk density structure and to construct a global radiative transfer model of the source. Our radiative transfer modeling and ATCA millimeter interferometry suggests that the disk mass might be comparable to the mass of the central object, which could result in observable self-gravition effects in the disk density structure. Observing in various line tracers should allow us to detect the rotation signatures of the disk and to determine the outflow properties close to the driving source. | Disks around high-mass stars | Disks and planet formation | 2019-01-27T22:00:38.000 |
| 2268 | 2022.1.00992.S | 48 | Fully characterization of streamers in the embedded phases of star formation | The classic picture of star formation follows the evolution of an isolated spherical dense core. In this picture all the material used in the star and planet formation process must go through the dense core. Clearly this an idealization, but it has helped to move forward our understanding of star formation. Recent observations have revealed streamers of gas toward objects at different evolutionary stages (from embedded Class 0 to more evolved Class II sources). This evidence for non-sperical accretion could deliver an important amount of mass and with a large enough mass infall rate that could severly change the disk formation and evolution process. Unfortunately, until now no systematic study has been able to determine the streamers' full lengths and properties. This proposal will observe a sample of 8 objects with strong suggestions for streamers in a systematic fashion to address these questions. These observations will enable the direct kinematical confirmation of the full extent of these streamers, and it will allow for a comparison of the properties across different evolutionary stages. | Low-mass star formation | ISM and star formation | 2024-10-24T17:23:25.000 |
| 2269 | 2021.1.00344.S | 9 | A sub-arcsec ALMA view of a luminous obscured AGN in a gas-rich protocluster at z=4 | Recently, ALMA identified an extremely gas-rich and star-forming protocluster at z=4. Chandra observations revealed that the second most gas-rich (molecular gas mass of ~1e11 Msun) member of the structure, namely DRC-2, hosts one of the most luminous (Lbol~1e47 erg/s), heavily obscured (NH>1e24 cm^-2) AGN known at all redshifts. DRC-2 is covered with ALMA observations in band 4 with relatively poor angular resolution (~1.6"). However, HST detected multiple rest-frame UV components separated by <1", which potentially contribute to the integrated ALMA flux, such that we cannot constrain the gass content and SFR of the AGN host galaxy. In addition, the buried AGN is the most plausible source powering a nearby extended (60 kpc) Lya blob (LAB), either via photoionization or shock-induced ionization due to an AGN-driven outflow. We propose to observe DRC-2 in band 4 at 0.4" resolution with the following goals: 1) to separate the contribution of the multiple HST components to the total ALMA flux, 2) to estimate the contribution of the ISM in DRC-2 to the heavy obscuration affecting the AGN, and 3) to investigate the presence of an AGN-driven outflow possibly powering the LAB via shocks. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-07-14T13:00:48.000 |
| 2270 | 2016.1.01010.S | 35 | Gas-dynamical Mass Measurements of the Black Holes in Red Nugget Relics | Supermassive black holes are key ingredients in galaxy evolution. One of the fundamental questions concerning black hole/galaxy co-evolution is whether black holes and galaxies grow in lockstep, or if the growth of one precedes that of the other. We propose to measure black hole masses using ALMA observations of cold, molecular gas disks on sub-arcsecond scales for three nearby galaxies that appear to be relics of the z~2 quiescent galaxies. The three rotating, early-type galaxies have uniformly old stellar populations and small sizes [effective radii of 1.5-2.9 kpc] for their stellar masses [(0.9-3.9)x10^11 solar masses]. Stellar-dynamical black hole mass measurements for a small number of other, similar compact galaxies showed that the objects are clear positive outliers from the black hole mass - bulge luminosity relationship. A significant population of z~2 red nugget local analogs whose black hole masses exceed expectations based on the galaxies' bulge luminosities will suggest that black holes grow before their host galaxy, having profound implications for the study of black holes and galaxy evolution. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2018-07-19T17:53:38.000 |
| 2271 | 2021.1.01147.S | 42 | Searching for Phosphine in the Atmospheres of the Ice Giants | We propose ALMA observations of the ice giant planets Uranus and Neptune to search for the spectral signature of phosphine in Band 6. Although phosphine is expected to be present in the tropospheres of the ice giants, as it is for Jupiter and Saturn, it has yet to be detected remotely. The unique capabilities of ALMA, namely its excellent sensitivity and wide observing bandwidth, permit precise, spatially resolved observations of the broad phosphine line at 266.9 GHz. These capabilities are necessary to overcome the limitations of prior disk-averaged observations, which have thus far only suggested upper limits on phosphine abundance. As phosphine is a disequilibrium species in the atmospheres of the ice giants, its abundance traces atmospheric dynamics, particularly vertical transport of trace species from the deep atmosphere. Comparative observations of Uranus and Neptune are proposed to assess their relative convection strengths. These observations will also provide new constraints on the P/H ratio of the ice giants as compared to the solar abundance. | Solar system - Planetary atmospheres | Solar system | 2023-09-21T19:18:19.000 |
| 2272 | 2015.1.00389.S | 21 | Molecular Gas Properties of HI Monsters | We propose to image 10 galaxies with a large neutral hydrogen reservoir, dubbed "HI monsters" in 12CO (1-0). In our previous single-dish CO study, they have been found with M(H2) = 3~11e9 Solar mass of molecular gas. Together with their large HI mass, M(HI) > 3e10 solar mass, our sample represents some of the most gas-rich galaxies identified to date in the Local Universe. Most of these galaxies do not differ from normal spirals in their optical morphology while they appear to be very inefficient in forming stars in spite of their large cold gas reservoir. This is intriguing since it is different from our expectation that cold gas can be directly translated into star formation activity in the context of galaxy formation and evolution. These extremely gas-rich galaxies can be an important populaton in probing the galactic parameters where the universal "Kennicutt-Schmidt" law is valid, but also in understanding galaxy growth in the epoch when the gas mass fraction in galaxies is thought to be much higher. To achieve > 5-sigma detection while keeping relatively good spatial and spectral resolutions, we request ~7 hours of ALMA observing time to cover the sample of 10 galaxies. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2017-03-31T02:42:31.000 |
| 2273 | 2016.1.00682.S | 14 | Early Structure Formation in Nova Shells | A new approach to the problem of how Nova shells structuring occurs is proposed. Using unique ALMA capabilities, we plan to observe gas condensations and globules by their continuum and NLTE recombination emission lines, aiming for an accurate physical diagnostic during the early phases of their evolution within the nova ejecta. The unprecedented images will provide clues to the formation, stability and destruction of shell globules in a broader stellar astrophysics context, in addition to the evolutionary relevant measure of mass segregation in clumps. Furthermore, the spectroscopic observations will provide unbiased estimates of the ejected mass from recombination lines. We request observations of Nova Sgr 2015 #2 at band 6 (continuum frequency 230 GHz and H30-alpha recombination line) with 0.029 mas resolution, which corresponds to the 12m array with maximum separation of 12.8 km. | Cataclysmic stars, Transients | Stars and stellar evolution | 2019-01-08T13:27:13.000 |
| 2274 | 2015.A.00015.S | 3 | Coordinated observations of Venus middle atmosphere with ALMA and AKATSUKI | The Japanese Venus orbiter AKATSUKI was successfully inserted into the Venus orbit on 7 Dec. 2015, and regular science operations just started in March 2016. This ALMA observation is proposed as a coordinated ground-based program to complement the AKATSUKI Radio Science (RS) experiments. We aim at revealing the thermal structure (together with the CO distribution and wind) of the dayside hemisphere of Venus middle atmosphere, which is not well understood from past observational studies conducted at much lower spatial resolution. Simultaneous Band-6 12CO and 13CO observations will enable us to constrain the thermal structure at altitudes 80-95 km, a vertical range that complements that of the temperature profile sounded by AKATSUKI RS. AKATSUKI RS can measure the temperature profile only at very localized areas, and therefore the high resolution mapping capability of ALMA will also be a strong support for interpretation of AKATUSKI RS data in terms of horizontal variation. Dates of AKATSUKI RS operation are restricted by the spacecraft's orbit. The period from March to early May in 2016 is the best, providing a unique opportunity to conduct collaborative observations using ALMA. | Solar system - Planetary atmospheres | Solar system | 2016-11-19T20:50:11.000 |
| 2275 | 2023.1.01619.S | 0 | Mining the ALMA Archive: Resolved High-z Schmidt-Kennicutt for Cheap | The spatially-resolved Schmidt-Kennicutt relation, which relates a galaxy's molecular gas mass density to its star formation rate density, is an essential tool for understanding how star formation is regulated in different galactic environments across cosmic time. The Schmidt-Kennicutt relation is also widely used in galaxy simulations. However, the relation has only been well-measured in the local universe due to the time-consuming nature of resolved molecular gas measurements at high redshift. A recent study compiled all spatially resolved CO observations for z=1-3 galaxies in the ALMA archive, but about half of the z>2 systems lack well-resolved maps of the obscured star formation. We therefore propose to map their dust continuum, matching the spatial scales of the gas maps. By leveraging the archival gas maps, the proposed program will complete the largest sample of spatially-resolved Schmidt-Kennicutt measurements at high redshift, with the smallest additional investment of resources. | Galaxy structure & evolution | Galaxy evolution | 2025-09-12T22:12:04.000 |
| 2276 | 2013.1.01202.S | 4 | Heating effects within the HH46/47 outflow | How energy is transported across outflow cavity walls onto the cold surrounding cloud material is virtually unknown. Although existing observations readily show the cavities and the cavity walls, they lack the spatial resolution to study the precise location and structure of the surface PDR through observations of the warm molecular and/or atomic gas. Clear variations in the gas distributions along the flows have been revealed. A large number of possible scenarios have been proposed for the heating effects. Most likely, multiple scenarios actually coexist within one flow, depending on local conditions and internal UV radiation. The best-studied outflow to date is HH~46/47. We propose to use ALMA to observe 17-21 positions along its red lobe. By targetting the CO 6-5 and [CI] 1-0 transtions at 0.3" spatial resolution, the emission profiles of both the molecular and atomic gas located within or behind the surface PDR and within the cavity will be spatially and spectrally resolved. This allows us to directly image the structure of the cavity wall, unambigiously determine the gas distribution of the PDR layer(s) and thus derive how energy is transported across the cavity wall. | Outflows, jets and ionized winds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 3000-01-01T00:00:00.000 |
| 2277 | 2018.1.01253.S | 23 | Molecular Line Diagnostics in Two Early-Type Galaxies | We propose to observe a suite of high-density molecular line diagnostics at ~ 2" to 3" resolution in NGC 4526 and NGC 7465, two nearby early-type galaxies. The galaxies are a Virgo Cluster member with dynamically relaxed gas (significantly processed by the intracluster medium) and an interacting galaxy in a small group. They are also known to have some unusual FIR fine structure line ratios and some unusual single-dish molecular line ratios. Here we focus on CS, CH3OH, HCN, HCO+, HNC, and 13CO transitions, at good enough angular resolution to differentiate the galaxy nuclei from their disks. The line ratios from these transitions will give greater insights into the properties of their molecular gas and how their ISMs have been processed; in addition, we will test a suggestion that CS/HCN may serve as a metallicity indicator in molecular gas. In general the early-type galaxies offer a broader perspective on the ISM than can be obtained from late-type galaxies alone. | Early-type galaxies, Galaxy chemistry | Galaxy evolution | 2020-01-18T01:04:03.000 |
| 2278 | 2023.1.00329.S | 0 | High-Resolution SZ Study of a Potential Phoenix-like Galaxy Cluster | We propose the first detailed imaging of the core of ACT-CL J1407.0+1048 (ACT1407), a high-redshift (z~0.836) galaxy cluster detected during the latest season of the survey campaign performed by the Advanced Atacama Cosmology Telescope (AdvACT). With a Sunyaev-Zeldovich (SZ) footprint measured to have a signal-to-noise ratio SNR=33.8, ACT1407 is one of the only two clusters detected by AdvACT with SNR>30 at redshift larger than 0.8. Nevertheless, observations with sufficient resolution and sensitivity are missing, and the physical details of the cluster are still unexplored. Observational hints suggest that ACT1407 may be analogous to the Phoenix Cluster, the only cluster known to have a core dominated by a "cooling flow". Only the information yielded by ALMA will allow for resolving for the first time the internal structure of ACT1407 via the study of its SZ signal. This will be key to understand whether the cluster is characterized by a cool core and, thus, may host a massive cooling flow. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 3000-01-01T00:00:00.000 |
| 2279 | 2018.1.01726.S | 277 | Suppressed fragmentation in the filaments of cluster-forming regions? | How does the fragmentation process proceed and give rise to the seeds of new stars in cluster-forming regions? Our recent ALMA data have revealed a peculiar fragmentation pattern in the young Mon R2 cluster; the fragmentation of the filaments feeding gas into the cluster is significantly suppressed compared to the filaments in low-mass star-forming regions. This implies that we have identified a crucial difference in how the formation of dense cores is regulated in cluster-forming- and low-mass star-forming regions. With this proposal, we wish to establish if the suppressed fragmentation is common in cluster-forming regions. If so, we have pinpointed a fundamental reason to expect the dense core population in cluster-forming regions to differ from that of low-mass regions, as recently observed by Motte et al. (2018, Nature Astronomy). To this goal, we will use band 3 continuum emission observations to map filaments feeding four cluster-forming regions and to determine their fragmentation patterns. Regardless of whether the suppressed fragmentation is found to be common, we will characterize the fragmentation of cluster-feeding filaments in unprecedented detail. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-08-20T11:40:45.000 |
| 2280 | 2015.1.00250.S | 17 | Resolving the molecular ISM in a unique star-forming disk galaxy at z=2 | We propose to obtain simultaneous imaging of the full molecular interstellar medium (ISM) in the best characterized star-forming disk galaxy at z=2, by targeting the CO(4-3), CO(7-6), and both [CI]1-0, 2-1 lines. These observations will provide a unique test on the predicted modes of gas accretion by resolving the kinematics and distribution of molecular gas into kpc-scale regions of active star-formation. This will enable an unprecedented view to the obscured star-forming regions that are hidden to the available UV/optical imaging and spectroscopy. We will be able to: (1) perform accurate modeling of the galaxy kinematics; (2) characterise the molecular gas in star-forming clumps; (3) test star formation laws; and (4) determine spatially-resolved ISM properties (e.g. H2 and [CI]masses, temperatures and abundances), as well as using the CO/[CI] line ratios as a proxy to the fraction of dense gas mass (versus total) to probe the gas excitation in kpc-scales. In combination with previous measurements of CO(3-2)/(1-0), these observations will enable us to put into context the physical properties of the ISM in this galaxy, thereby informing similar future studies on large samples. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-03-03T19:27:57.000 |
| 2281 | 2018.1.00423.S | 49 | H2S as a tracer of shocks in AGN outflows | There is growing evidence that nuclear activity can power massive molecular outflows. These outflows help regulate the growth of galaxy nuclei and the implied outflow momenta suggest that the inner regions of these galaxies may be cleared of material with in a few Myr. Recent detections of very dense (n>1e4 cm-3) molecular gas in some outflows raises questions on the origin and fate of the dense gas. It has been suggested that it is linked to the presence of internal/external processing shocks in the outflows. These processes are important since they may for example lead to cloud compression and star formation in the outflows. Shocks may also dissipate and decelerate rotation or instabilities in the outflow, or aid in its deceleration. We hereby propose a search for the luminous shock tracer H2S in a small sample of AGN outflows. H2S is an excellent tracer of fast mantle-processing shocks and its abundances can be very high - similar to those of the standard dense gas tracer HCN. We aim to see if shocks are correlated with outflow velocity and type of outflow - ranging from jet driven collimated outflows to wide angle AGN winds. | Outflows, jets, feedback | Active galaxies | 2020-09-01T00:00:00.000 |
| 2282 | 2015.1.01067.S | 13 | Disks Around Outbursting Young Stars | FU Orionis objects (FUors) are young stars observed to flare by several magnitudes in the optical and remain bright for decades or longer, with the flares attributed to enhanced accretion from surrounding disks. FUors may represent the optically visible, late stages of a cycle of episodic accretion throughout the protostellar stage of star formation, or they may represent an extreme, unique class of young stars; debate continues on this topic. A range of possible driving mechanisms for the accretion bursts have been proposed, including disk gravitational instabilities, thermal instabilities, a combination of gravitational and magneto-rotational instabilities, and binary interactions. The physical structure of FUor disks and the host star masses, both key ingredients for a complete understanding of the physical origin of these extreme accretion events, remain unknown. We propose a survey of FUors at 0.1" resolution. With these data we will spatially resolve the disks, accurately map their gas kinematics, and characterize both the spatial distribution and total amount of mass in FUor systems, providing key observational constraints on burst driving mechanisms. | Disks around low-mass stars | Disks and planet formation | 2018-03-12T05:29:53.000 |
| 2283 | 2021.1.01337.S | 18 | (Re)solving the Mysteries of a lensed dwarf-dwarf Galaxy Merger at z~3 | Mergers are an important mechanism of galaxy assembly at all redshifts. The most extreme systems are characterized by severe dust obscuration and infrared luminous starbursts. A connection between these rare events and the more typical systems seems to lie in the development of extended Lyman alpha halos. A remarkable example of this is the strongly lensed interacting LBGs pair SGASJ1226 which other than a extended halo presents mild dust continuum emission but surprisingly high [CII] emission, as seen in unresolved ACA and Herschel data, respectively. The proposed observations will help us explain where is the [CII] emission is coming from and how it relates with the merging activity and the Lya halo. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-01-05T10:27:13.000 |
| 2284 | 2016.1.00447.S | 37 | Anatomy of a midlife crisis: can sigma Orionis disks still make Jupiters? | We propose to measure the gas and dust content of circumstellar disks in the middle-aged (~3-5 Myr old) sigma Orionis cluster to see whether they have sufficient material to form gas giants. Our sample consists of all 34 spectroscopically identified members of the cluster with Spitzer mid-infrared excesses and stellar masses greater than 0.5Msun, so as to allow a direct comparison with recent ALMA observations of Lupus. In addition, our previous JCMT/SMA observations show that these disks have detectable continuum emission and are associated with gas. If the sigma Orionis disks have not greatly evolved relative to the younger Lupus disks, we should detect all in 13CO and many in C18O. If our detection rate is much lower, however, we can make significant statements about disk gas mass evolution and planet formation timescales. In particular, if insufficient gas remains in these middle-aged disks to form Jupiters, we will be able to place firm limits on the formation history of our Solar System. | Disks around low-mass stars | Disks and planet formation | 2018-08-13T22:00:26.000 |
| 2285 | 2015.1.01222.S | 55 | Investigating the nature of a new dust obscured star forming galaxy which can only be understood via deep ALMA spectroscopy | We propose to conduct a blind search of the CO emission lines toward SXDF-ALMA3 wich is discovered by ALMA 1.1 mm deep observations of contiguous 1.5 arcmin^2 window in the SXDF-UDS-CANDELS field, with 5 sigma sensitivity of 0.28 mJy. One of the brightest ALMA source, SXDF-ALMA3 (the target), is very dark in deep WFC3/HST and HAWK-I/VLT NIR images as well as VLA 1.4 GHz and 6 GHz images, despite the fact that this source rather bright (0.84 +/- 0.09 mJy in 1.1 mm, corresponds to L_IR ~ 1 x 10^12 L_sun or SFR ~ 170 M_sun/yr), which suggests that ALMA deep surveys can unveil dust obscured star forming galaxies which are difficult to identify even with the deepest NIR/radio surveys. The main aim of this proposal is as follows: (1) Determining its redshift by scanning CO lines across the band 3 to test whether SXDF-ALMA3 is significantly above the star-formation main sequence at its epoch or not. (2) Revealing the molecular gas mass fraction of SXDF-ALMA3 to assess its star formation mode. Through the proposed observation, we aim to characterize the nature of this dusty starburst galaxy which is can only be understood via deep ALMA spectroscopy. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2017-09-09T03:07:56.000 |
| 2286 | 2018.1.00621.S | 12 | Magnetic field in the evolving jet of GRS 1915+105 | Polarization observations in the millimeter regime have been proven to be crucial in determining the magnetic field structure close to the jet base in active galactic nuclei and providing discriminatory power in the determination of the proper model for the jet structure. However, up to date, mm-band linear polarization measurements are lacking from jets around stellar-mass black holes. Given their small black hole masses, they evolve through a wide range of accretion rates on timescales accessible to people, unlike active galactic nuclei, thus providing unique opportunities to study the jet evolution. Here, we propose to observe the linearly polarized jet emission of the transient black hole X-ray binary GRS 1915+105 with ALMA. These observations will be used to measure the strength and morphology of the magnetic field in different stages of the jet evolution providing a quantitative understanding of the physics involved in the jet production and offering crucial information to distinguish between models of discrete ejections or shocks propagating along quasi-continuous flows. | Black holes, Transients | Stars and stellar evolution | 2020-08-22T12:45:22.000 |
| 2287 | 2023.A.00035.S | 0 | Identifying the relativistic outflow associated with SN Ic-BL 2022xxf | Broad-line type Ic supernovae (SNe Ic-BL) provide a link between SNe and Gamma-Ray Bursts (GRBs), being a key object in understanding the extreme outcome of massive-star core-collapse. One important distinguishing feature of SNe Ic-BL has been suggested to be the existence of (sub-) relativistic outflow driven by the `central engine'. SN Ic-BL 2022xxf showed a unique double-peaked light curve in the optical indicating dense circumstellar material (CSM), and recently we have discovered late-time rebrightening in cm emission. The properties of the cm signal show striking differences from canonical SNe, and similarities to GRB afterglows (AGs). With the proposed high-frequency observations through DDT, we will for the first time robustly confirm the relativistic outflow associated with an SN Ic-BL and study the nature of the central engine in details. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2025-01-30T20:16:30.000 |
| 2288 | 2021.1.00247.S | 58 | Golden Reference for Metallicity Measurements at z=6-7 by ALMA+JWST | We propose deep [OIII]88um, [NII]122um/205um spectroscopy targeting two remarkably bright, lensed sub-L* galaxies at z=6.07-7.13 recently discovered with ALMA [CII]158um observations. JWST NIRSpec IFU observations have been scheduled for both galaxies targeting rest-frame optical lines. Our prime goal is deriving gas-phase metallicities at z>6 based on the robust direct electron temperature method. Although the direct method usually relies on temperature-sensitive auroral lines that are too faint to detect from sub-L* galaxies at z>6, the strong lensing and joint analysis of ALMA+JWST allow us to accomplish this goal by combining measures of the density-sensitive lines of [NII]122um/205um and temperature-sensitive lines of [OIII]88um (ALMA) and [OIII]5007 (JWST). Our program will offer robust measures of the metallicity in typical galaxies with Mstar~10^9 Msun at z~6-7, for the first time. Strongly lensed properties will also allow us to probe the metallicity gradient within the galaxies. We also characterize the obscured properties by securely constraining the dust temperature via the underlying continuum at rest-frame 88um, 122um, 158um, and 205um. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2023-09-21T15:45:55.000 |
| 2289 | 2011.0.00604.S | 0 | Tracing Evolution of Warm Carbon-Chain Chemistry in L1527 | A thorough understanding of chemical composition of low-mass star forming regions and its evolution to protoplanetary disks is one of the central issues for astrochemistry, astrophysics, and planetary science, since it is eventually related to an origin of rich substances in our solar system. Recent discoveries of hot corinos and the warm carbon-chain chemistry (WCCC) sources demonstrated significant chemical diversity in low-mass Class 0 protostars. Now we have an important question how these two types of chemistry evolve toward the later stages. With these in mind, we here focus on the chemical evolution of the WCCC source, and investigate the molecular distributions of the prototypical WCCC source, L1527, at the high resolution (<1") with ALMA cycle 0. Since the chemical evolution would be more advanced in a more inner region around the protostar, we can trace the direction of the chemical evolution from the spatial distribution. For this purpose, we fist observe the spectral lines of carbon-chain molecules, which are characteristic to the WCCC sources, to investigate their possible depletion/destruction in the inner part. In addition, we observe the spectral lines of H2CO and CH3OH, which are known to be a good tracer of hot corinos, to search for the hot corino activity in the innermost part of the WCCC source. These results will provide us with crucial information on the chemical evolution of the WCCC source toward the Class I and later stages. They are also important for establishing our unified picture of carbon chemistry in low-mass star forming region, including hot corino chemistry and WCCC. This observation is only possible with the ALMA sensitivity and resolution, although the source is located in the northern hemisphere. | Astrochemistry, Low-mass star formation | ISM and star formation | 2014-01-16T07:08:00.000 |
| 2290 | 2024.1.00520.S | 0 | The largest survey of dense gas in high-redshift galaxies | Dense gas is the key to star formation. However, despite two decades of effort, very little is known about dense gas (>10^4 cm-3) at z>1. This is because the standard dense-gas tracers: HCN, HCO+, and HNC are very faint; consequently, just a handful of detections have been reported at z>1. This severely limits our understanding of star-forming processes during the epoch when the cosmic star-forming activity peaked. We propose to drastically remedy this situation by observing the HCN/HCO+/HNC lines in 18 z=1.2-3.5 (mostly) gravitationally lensed galaxies from the Herschel survey: the largest and deepest such survey to date. Using newly-derived HCN excitation for high-z galaxies, we will derive robust dense-gas masses for our targets, putting strong constraints on the dense-gas fractions and star-forming efficiency as a function of star-formation rate and redshift. This project will yield a major breakthrough in our understanding of star formation at high redshift, and a springboard to future spatially resolved studies. | Sub-mm Galaxies (SMG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 2291 | 2018.1.01330.S | 9 | Unveiling the origin of dust gaps in HD143006 via CO observations | Our recent high angular resolution ALMA observations revealed remarkable substructure in the continuum of the HD 143006 protoplanetary disk, which features three rings and a vortex-like asymmetry. Such features have been hypothesized to result from interactions between the disk and one or more giant planets, but models of other disk processes can yield similar features in dust emission. A key avenue for distinguishing between hypotheses for explaining dust substructures in a protoplanetary disk is to measure its gas surface density profile. A Jupiter-mass planet may create a gas gap depleted up to several orders of magnitude, which can manifest as a gap in CO emission. To investigate whether one or more giant planets is responsible for the complex structures observed in HD 143006, we propose high angular resolution observations of 13CO to trace the gas surface density profile. These line measurements, in conjunction with our ALMA and SPHERE observations of the dust disk and our ongoing direct imaging search, will provide valuable insight on the mechanisms creating common disk substructures. | Disks around low-mass stars | Disks and planet formation | 2021-01-29T20:58:31.000 |
| 2292 | 2021.1.00575.S | 18 | IRAS 04166 and the origin of the EHV component in outflows | Bipolar outflows play a crucial role in the process of star formation, but many aspects of their physics remain poorly understood. Here we propose to investigate the nature of the so-called Extremely High Velocity (EHV) gas, which represents the most collimated, jet-like component seen in the youngest outflows. This component was originally interpreted as resulting from molecular bullets, but recent work suggests that it arises from internal shocks inside a time-variable jet. To investigate this component, we have chosen the outflow from IRAS 04166+2706, a nearby protostar with the most symmetric (and likely pristine) EHV component. Previous ALMA observations of two outer EHV peaks in this source support the jet-shock interpretation of the EHV gas. By mapping the full set of 14 EHV peaks identified with previous PdBI and SMA observations, we will fully test the jet-shock interpretation, study the propagation of the EHV component from the protostar, and test whether the transfer of momentum from the EHV component can potentially accelerate the rest of the outflow. These observations will provide the most complete picture of the EHV gas in outflows currently achievable. | Outflows, jets and ionized winds | ISM and star formation | 2023-01-24T15:19:11.000 |
| 2293 | 2012.1.00623.S | 10 | Build-up of massive galaxies in the cluster core at z=1.46 revealed by resolved dusty star formation within galaxies | XMMXCS J2215.9-1738 cluster at z=1.46 is one of the most distant, massive X-ray clusters. From our narrow-band imaging survey of [OII] emissions from cluster members with Subaru/Suprime-Cam, we have discovered that the star forming activity in this cluster core is still very high, and comparable to that in the surrounding low density environments. Interestingly, massive [OII] emitters with high star formation rates tend to show clumpy structures with diffuse UV emissions. These galaxies in the cluster core are still in the course of vigorous formation, and we must be witnessing the site of massive spheroidal galaxies formation. We here propose to conduct high-resolution ALMA observations of 13 [OII] emitters in the cluster core with C32-6 configuration at Band-7 so that we can spatially resolve their dusty star formation activities within galaxies with a resolution down to ~1.5 kpc. We emphasize that it is nearly a SFR-limited, complete sample of star-forming galaxies with SFR > 93 Msun/yr. Combined with the existing HST images with the comparably high resolution at the rest-frame UV, we will be able to map out the internal distribution of star formation activities, both dust obscured and unobscured ones, for the first time. From that we aim to identify the physical process which triggers the intense star formation in the high density environment. This project will reveal how the present-day cluster galaxies were built-up in their formation phase before they eventually became passive. | Starburst galaxies, Galaxy Clusters | Active galaxies | 2016-10-22T19:02:07.000 |
| 2294 | 2017.1.00831.S | 45 | Skimming the Surface: An Absorption Study of HDO in a Young Protoplanetary Disk | Cold water vapor revealed by energetic UV photodesorption of icy mantles in the outskirts of protoplanetary disks provides a unique view into the composition of their largely invisible ice reservoir. Surface water (H2O) emission has been detected via this mechanism, however interpretation requires uncertain excitation modeling to derive a column. Based upon our Herschel PACS observations of water towards the young and inclined protoplanetary disk, RY Tau, we find that the data are strongly suggestive of deep unresolved self-absorption. We propose an experiment to measure HDO in absorption against the dusty continuum to determine the column density of cold HDO vapor and thereby obtain the first estimate of the D/H ratio in a young planet-forming disk with ALMA. If this photodesorbed layer is representative of the ices themselves, which grow and settle out over time, we are directly probing the composition of the gas that becomes incorporated into planetesimals, comets, etc., i.e. the building blocks of planetary systems. Such observations will provide important constraints on the initial HDO/H2O ratio of disk ices down to Earth's ocean-levels (VSMOW) and potentially lower. | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-02-21T23:58:01.000 |
| 2295 | 2013.1.00018.S | 13 | Understanding the Origins and Dynamics of the Multiple Outflows Around IRAS 16293-2422 | Jets and outflows are the most obvious signposts of ongoing star formation, when the accretion during the Class 0 phase powers bipolar ejections perpendicular to the forming disk. Many nearby star-forming regions show multiple bipolar outflows coming from a single protostellar core, which is a sign for the formation of multiple protostars. This proposal aims at getting the first complete picture of the interaction, morphology and kinematics of outflows within such a protostellar system. We target IRAS 16293-2422, one of the best-studied Class 0 systems. It consists of a protobinary (Source A and B), separated by 600AU. Source A is also a binary system with a separation of 36AU. Our aim is to fully resolve all known sources and their outflows in both the velocity and spatial domain to understand the interplay between the outflows, the ambient medium and the forming stars. To pursue that goal we target CO(3-2) and 13CO(3-2) - to get the full dynamics of the outflow - CS(7-6) and C34S(7-6) - to get the infall motions towards the sources, and the dynamics of the dense gas in the disk - and SiO(8-7) - a shock tracer to understand the interaction of the outflows with the quiescent gas. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2016-05-04T12:18:07.000 |
| 2296 | 2015.1.00490.S | 13 | Resolving the double gaps in the disk around HD 169142 | Recently, near-infrared observation revealed a possible double-gapped structure in the transitional disk around the Herbig Ae star HD 169142. Such double-gapped structure can be a smoking-gun evidence that the forming planets are actually present in the disk. However, the NIR detected gap can be either a true radial gap or rather a shadow casted by the inner disk structure. Here we propose to make high angular resolution imaging of the dust and gas disk around HD 169142 with ALMA in Band 7 & 6. With this observation, we can discuss the distribution of dust and gas in the gaps simultaneously. When both the dust and gas are depleted in the gaps, it strongly indicates that the forming planets are responsible for such double-gapped structure. From the depth of the gap, we can estimate the mass of the gap opening planet as low as Neptune mass. When only the dust is depleted and the gas component remains in the gaps, it implies that the grain growth is a likely cause of the double-gapped structure of dust disk. In any case, this observation will reveal the origin of the amazing double-gapped structure found in HD 169142 disk, and it will contribute our understanding of planet formation. | Disks around low-mass stars | Disks and planet formation | 2018-01-21T01:55:49.000 |
| 2297 | 2016.1.00154.S | 17 | The origin of Titan's external oxygen | Titan's atmospheric inventory of oxygen compounds are thought to result from photochemistry acting on externally supplied oxygen species. These species originate from: (1) cryogenic plumes from the volcanic moon Enceladus and (2) micrometeoroid ablation. These sources have extremely different chemical makeups so will play very different roles in Titan's photochemical cycle. Enceladus is suspected to be the major source of O+, which is required to create Titan's CO. However, the relative contribution to OH and H2O fluxes from Enceladus versus micrometeorites remains unknown. Here we exploit sulphur as a tracer, which has very different relative sulphur to oxygen elemental abundances in micrometeorites (S/O ~10^-2) compared to Enceladus' plumes (S/O ~10^-5). Photochemical models predict most sulphur converts to CS, which has strong sub-mm emission lines. Therefore, observing CS provides a diagnostic tracer, which will allow us to determine the source of Titan's external water and OH for the first time. This will provide unique constraints on the small impactor flux into Titan's atmosphere, which could be extrapolated to the wider Saturnian system. | Solar system - Planetary atmospheres | Solar system | 2018-03-28T16:10:25.000 |
| 2298 | 2013.1.00395.S | 57 | The Evolution of Disks Around Low-mass Stars | The lifetime of primordial, optically thick disks around young stars places empirical constraints on the timescale to form planetary systems. Submillimeter observations play a critical role in quantifying the evolution since the emission is optically thin over most of the disk and probes the cool material where most of the disk mass resides and where most planets form. We request time with ALMA to image the dust and gas toward a complete sample of disks around stars in the 5-11 Myr old Upper Scorpius OB Association that have spectral types between M4.75 and G0, corresponding to stellar masses between about 0.2 and 2 Msun. Upper Sco is the nearest OB association of this age, and thereby provides an opportunity to obtain sensitive measurements of the disk properties at the end stage in the lifetime of primordial disks. By comparing the dust emission from disks in Upper Sco with existing continuum observations of 1 Myr stars in Taurus, we aim to measure 1) the amount of dust that is dispersed from disks on 5-10 Myr timescales, 2) the efficiency of disk dispersal as a function of stellar mass, and 3) how the dust mass evolves between evolutionary states. | Disks around low-mass stars | Disks and planet formation | 2015-10-20T11:22:15.000 |
| 2299 | 2011.0.00652.S | 0 | Deciphering black hole feedback: molecular outflow in an obscured quasar | We propose to search for outflowing molecular gas in the obscured quasar SDSS J1356+1026. This nearby (z=0.123) luminous quasar is blowing a 10kpc-scale bubble of ionized gas, and provides strong evidence that black holes can inject energy into their large-scale environments without the help of star formation or radio jets. The bulk of the outflow may well be in the molecular phase, and we will search for it with CO(1-0) and CO(3-2) observations with ALMA. We will probe the majority of the outflowing mass and reveal the physical conditions of the outflow. SDSS J1356+1026 provides the key to understanding the prevalence of black hole energy injection in the growth and evolution of galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2013-10-04T20:22:00.000 |
| 2300 | 2017.1.00404.S | 12 | Using Hydrogen Recombination-line Masers to Trace Disk and Wind Dynamics in MWC 349A | Disk winds are thought to play a critical role in star birth. As winds extract excess angular momentum from accretion disks, matter in the disk can be transported inward to the star to fuel mass growth. However, the observational evidence of wind carrying angular momentum has been very limited. We propose ALMA observations of a rare hydrogen recombination-line maser object MWC349A. The high signal-to-noise ratios made possible by the maser emission process and high spectral dynamic range of ALMA allow us to constrain the relative astrometry of the maser spots to 0.1 milli-arcsecond precision. By improving relative astrometry by one order of magnitude over the previous SMA and PdBI studies, this project will determine how angular momentum is transfered to the wind within a radius of 25 AU, and inform theoretical models of jets and outflows. | Outflows, jets and ionized winds | ISM and star formation | 2020-12-25T10:40:21.000 |
| 2301 | 2015.1.00528.S | 12 | The onset of molecular outflows in star formation: search for an outflow driven by a first-core candidate | Molecular outflows play a key role in extracting angular momentum and regulating the star formation efficiency of collapsing dense cores. While molecular outflows were initially thought to be entrained by high-velocity jets, a new outflow paradigm has emerged thanks to 3D MHD simulations which show that a slow outflow appears right after the formation of the first hydrostatic core, i.e. before the formation of the protostar and the onset of the jet. This new paradigm of two flows (slow outflow/fast jet) initiated at different evolutionary stages (first core/protostar) has yet to be proven observationally. Detecting outflows during the first-core phase is a simple way to test the model predictions and verify this paradigm. We propose to search for a compact, slow outflow in a promising, first-core candidate in a nearby molecular cloud. The predictions of our state-of-the-art 3D radiation-MHD code set the technical parameters required to detect such an outflow in CO 3-2. This project will be an excellent showcase of the synergy between powerful observational instrumentation and cutting-edge theoretical modeling in the field of star formation. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-03-10T21:09:01.000 |
| 2302 | 2017.1.00009.S | 1 | Oscillations and waves contributing to coronal heating on the Sun | The mechanism responsible for heating the solar corona is one of the most fundamental problems in solar physics and astrophysics in general. Recent observations by the Hinode and IRIS satellites have revealed that the solar atmosphere is filled with small-scale oscillations caused by waves that can carry sufficient energy to heat the corona. However, it is unclear whether waves actually contribute to coronal heating, because of the difficulty in measuring the temperatures of chromospheric features in the corona. ALMA is the first instrument that can directly measure the temperature of the highly-resolved chromosphere. We propose observations of prominences above the solar limb for several hours jointly with ALMA and IRIS. By comparing a temperature map by ALMA with the spatial distribution of waves along fine structures of prominences observed by IRIS, we can directly investigate the temperature variation associated with the presence of waves. The relationship between temperature changes and wave properties will provide critical information about the mechanism of wave dissipation and thus tightly constrain wave-heating models. | The Sun | Sun | 2019-06-07T00:00:00.000 |
| 2303 | 2024.1.01654.S | 0 | Hide and seek: searching for hidden methanol in Band 1 | Complex organic molecules (COMs) have been detected abundantly in dozens of protostellar objects using interferometer arrays. Among the COM inventory, methanol (CH3OH) is the simplest and the most abundant species. However, methanol remains undetected in more than half of the embedded protostars that have been surveyed so far. Even in some binary systems, two components show distinct richness of COM chemistry. This leads to a straightforward question: why does the presence of COMs show such a big difference among protostars? One explanation is that COM emission is blocked by optically thick dust at millimeter wavelengths (e.g. ALMA Band 6/7) that are usually observed. It is possible to see the hidden emission at longer wavelengths where dust opacity becomes insignificant. The newly available Band 1 since ALMA Cycle 10 provides a great opportunity to verify this hypothesis. Whether detection or non-detection of methanol in Band 1 will be crucial to answering if dust opacity is important in studies of COMs. | Low-mass star formation | ISM and star formation | 2025-10-15T10:37:12.000 |
| 2304 | 2022.1.01576.S | 68 | (How) do low-luminosity radio AGN affect star formation in their host galaxies? | Leading models of galaxy evolution postulate that AGN may regulate star formation in galaxies by injecting a fraction of their energy output into the surrounding gas, thereby inhibiting star formation over long times. However, a direct link between AGN activity and a suppression of star formation is very difficult to come by. We will observe CO(1-0) in 8 nearby Seyfert galaxies with kpc-scale radio emission indicating that radio plasma from the AGN percolates through their ISM to kpc distances. Recent hydrodynamic simulations suggest that this plasma could enhance local gas turbulence and lower star formation rates, when adopting the framework of turbulence-regulated star formation that is now widely accepted in the ISM community. This is part of a multi-wavelength project including optical IFU spectroscopy. We will map the local gas velocities and line widths and compare with warm ionized gas, star formation, and stellar populations observed in the optical to trace the distribution of AGN energy in the ISM and its impact on star formation. We are also carrying out dedicated, matched relativistic hydrodynamic simulations for a quantitative interpretation of our results. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-02-03T18:38:19.000 |
| 2305 | 2017.1.00237.S | 156 | The formation of high-mass binary systems by core/disk fragmentation | Different mechanisms have been suggested to explain the binarity of high-mass stars: core fragmentation, disk fragmentation, and multiple-body interactions. So far, there is no observational constraints to assess their importance. With the unique ALMA capabilities, we can for the first time statistically test these scenarios. Using continuum emission at 230 GHz to derive the multiplicity fraction and the distribution of companions separation at 0.06" (100AU at 2kpc; 200AU at 3.8kpc), we can resolve star-forming cores and the predicted disks (~1,000 AU) around high-mass stars. With a large sample of 47 cores hosting massive young stellar objects, we will address: What is the binarity rate of high-mass cores at ~100s AU scales? How does the binarity rate change as cores evolve? Are high-mass binary systems formed at core scales (>1,000AU) or disk scales (<1,000AU)? [NOTE] [This is partial resubmission of a ranked B proposal from Cycle 4. The source list has been expanded in 30%. Extended config. (0.06") obseration are scheduled for August 2017. Compact conf. (0.3") has been partially delivered. We will withdraw the observations from Cycle 5 for targets that are observed in Cycle 4] | High-mass star formation | ISM and star formation | 2021-02-11T09:56:11.000 |
| 2306 | 2016.1.00433.S | 65 | Deuterium depletion in a molecular cloud? | Deuterium is one of the few elements created at the Big Bang and is destroyed at the interiors of stars. Recent observations in metal-poor, damped Lyman alpha systems show a significant scatter in the D/H measurements, by about a factor two, whose origin is debated. Furthermore, although a gradient of the D/H abundance is expected across the Galaxy, the observed D/H abundance ratio in the ISM shows no systematic trend with the metallicity but, again, a large scatter that cannot be accounted for solely by Galactic chemical evolution models. Among the various hypothesis done to explain this behavior, the ISM observations leave only the possibility that, in very cold and dense regions, atomic (D) and/or molecular deuterium (HD) might be frozen into the volatile grain mantles. The goal of this proposal is to provide the first measurement of the D and/or HD depletion in the ISM. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-05-04T00:03:00.000 |
| 2307 | 2022.1.01408.S | 10 | Carbon grain sublimation: a new top-down component of protostellar chemistry | Earth's carbon deficit has been an outstanding problem in our understanding of the formation of our Solar System. A possible solution would be the sublimation of carbon grains at the so-called soot line (~300 K) early in the planet-formation process (i.e., protostellar stage). The most likely signatures of this process are an excess of hydrocarbons and nitriles inside the soot line, and a higher excitation temperature for these molecules compared to oxygen-bearing complex organics that desorb around the water snowline (~100 K). We propose a pilot program toward two nearby high-mass protostars that exhibit signatures of carbon grain sublimation. These observations will spatially resolve the soot line and are able to reveal whether an enhancement in column density of nitrogen-bearing molecules occurs across the soot line. Moreover, these observations will show whether it is necessary to resolve the soot line, or whether excitation temperatures measured over larger spatial scales are sufficient. In addition to establishing whether carbon grain sublimation could be active toward the two sources in our sample, this program will inform future studies of low-mass protostars. | High-mass star formation, Astrochemistry | ISM and star formation | 2024-05-09T18:51:41.000 |
| 2308 | 2018.1.00124.S | 20 | Zooming into molecular tori | In our previous ALMA proposals, we have detected for the first time with CO(6-5) the molecular torus of 10pc diameter in the Seyfert 2 galaxy NGC 1068 (Garcia-Burillo et al 2016). Surprisingly, the torus is tilted, warped, and its kinematics is dominated by turbulence and non-circular motions. We have very recently mapped the molecular tori in 7 other AGN targets, at 5-10pc resolution, and found a large variety of radii and masses. Two of them are very dense and reach towards the center. We propose now to resolve the morphology and dynamics of these 2 tori in CO(6-5) at ~2pc resolution, with 0.03'' beam in Band 9, to explore their clumpy and turbulent structure, and also detect for the first time the dust emission of their torus. We will then be able to understand this key structure, for different radio power and star forming rates, and quantify the various evolutionary phases of fueling and feedback processes. Well inside the sphere of influence of the black hole (BH), we will be able to determine accurately its mass, for Seyfert spiral galaxies, in a region of the M-sigma relation (or M_BH-M_bulge relation) where the scatter is maximum. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-01-22T10:17:24.000 |
| 2309 | 2018.1.01023.S | 343 | Star-birth in Irradiated Environments: Free-Floating EGGs in the Rosette | Massive stars have a profound effect on the next generation of stars to form in their vicinity. Their ionizing radiation produces evaporating gaseous globules (EGGs) and photo-evaporating protoplanetary disks (proplyds). Our recent discovery of a new class of free-floating EGGs (frEGGS) in nearby massive star-forming regions (MSFRs), which had been previously classified as proplyds because of their morphological similarity, represents a poorly-studied pathway for star formation to proceed in MSFRs. We propose to carry out 4" imaging of the 12CO and 13CO J=3-2 lines towards a sample of 28 frEGGs in the Rosette MSFR, enabling us to measure the sizes of their molecular cores (and thus their temperatures and masses), and (if resolved) constrain the density structure in the frEGG (which likely differs from that of a standard star-forming cloud core because of the high-pressure external boundary condition). The data will reveal the presence of any outflows associated with young stellar objects in the frEGGs. This study will pave the way for more extensive future studies of frEGGs, and helping us understand triggered star formation in the vicinity of massive stars. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2021-05-08T00:00:00.000 |
| 2310 | 2022.1.00119.V | 0 | Ultra-high resolution imaging of 3C84 (Resubmission) | 3C84 is a prime target for high angular resolution studies of jet formation, due to its proximity and large SMBH mass, which provides a spatial resolution of 20 Rs. Previous 1.3cm RadioAstron space-VLBI imaging and 3mm GMVA maps show a prominent two rail jet, which is anchored in an E-W oriented compact component, perpendicular to the outer jet. With the proposed EHT+ALMA observation we address the question of the physical nature of this elongated jet base and the "true" location of the jet apex. EHT imaging with ultra-high angular resolution will allow for a number of questions to be answered: the Faraday depth, magnetic field and particle density can be estimated through the rotation measure. The location of the jet base will be precisely pinpointed. The transverse jet width and nozzle (profile) will allow for a discrimination between magnetic and/or pressure confinement in the jet launching region. Finally, the magnetic field topology and orientation will be constrained by polarisation imaging. These parameters will set important constraints for the future theoretical modelling of BH jet launching. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 3000-01-01T00:00:00.000 |
| 2311 | 2013.1.00586.S | 108 | Testing Schmidt's Conjecture in NGC 300: Bridging the Gap between Galactic and Extragalactic Star Formation | A little more than a half-century ago, Schmidt conjectured a power-law scaling relation between the star formation rate and interstellar gas surface densities in galaxies. Much of our understanding of extragalactic star formation is based on this scaling law. However, recent studies of galactic GMCs indicate that our understanding of the Schmidt law may need to undergo serious revision. These studies demonstrate that there is no Schmidt scaling law that relates the SFR and gas surface densities between galactic GMCs. Consequently the empirically derived Schmidt scaling relation for disk galaxies is likely an artifact of unresolved measurements of extragalactic GMCs and not a result of an underlying physical law of star formation. Here we propose to extend our MW studies with an ALMA CO survey and pilot HCN observations of the GMC population in the nearby disk galaxy NGC 300 to: 1) assess the extent to which the physical process of star formation operating in local MW clouds describes the star formation in NGC300, 2) critically test the nature of the Schmidt law in an external star forming environment and 3) bridge the gap between galactic and extragalactic star formation studies. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2016-03-02T18:58:15.000 |
| 2312 | 2013.1.00960.S | 283 | The first Galaxy-scale hunt for the earliest phases of the formation of the most massive stars | The origin of massive stars is a fundamental open issue in modern astrophysics. Pre-ALMA interferometric studies reveal precursors to early B to late O type stars with collapsing envelopes of 15-20 Msol in 1000-3000 AU. There are exceptionally few examples known to date of more massive envelopes at these size-scales. Do massive collapsing envelopes exist within this size-scale up to the 100msol regime? Do they form the same way as the so far observed 8-20 Msol regime? To answer these questions a statistical sample is the necessary next step. Here we target a well characterized sample of massive and cold clumps above 650 Msol within 4.5 kpc identified by the ATLASGAL survey in order to reveal the most massive individual collapsing envelopes on 3000 AU size scales (with 0.6" angular resolution). We will drastically increase the number of 20-100 Msol envelopes known to date. We also target molecular tracers to distinguish between pre-stellar and protostellar condensations allowing statistical life-time estimates for the elusive pre-stellar phase. This comprehensive study represents a significant leap forward in our understanding of the origin of the most massive stars. | High-mass star formation | ISM and star formation | 2016-04-17T14:32:33.000 |
| 2313 | 2018.1.00575.S | 38 | The Formation of Massive Galaxies in the Reionization Era | We request spectral imaging of a unique system of massive galaxies in the epoch of reionization (EoR). SPT0311-58 was selected via its millimeter-wavelength dust emission in the South Pole Telescope survey and is spectroscopically confirmed to lie at z=6.900. The most massive galaxy in this system has the highest dust, gas, and dynamical masses of any galaxy known at z>6, and the pair resides in one of the largest halos that can exist at z~7 (Marrone et al. 2018). We have obtained high SNR detections of the CII and OIII lines and built a detailed gravitational lens model for the system. We propose to obtain 1) key diagnostic line images to interpret the significant variations in the ratios between CII, OIII, and continuum, 2) higher resolution CII imaging (mostly completed in cy5) to further explore the dynamics and stability of the ISM in these galaxies, and 3) spatially-resolved measurements of an outflow tracer to study the deposition of metals in the IGM during the EoR. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2020-01-02T20:18:14.000 |
| 2314 | 2016.1.00863.S | 18 | Does Polarization from Scattering Contaminate Magnetic Field Observations in Star Forming Regions? | Polarized emission from aligned dust grains have been used to successfully probe the structure of the magnetic field in regions of star formation. This technique was used to conduct polarization observations towards IRAS 16293B which is a young stellar object with an almost face on geometry. The SMA observations showed that the magnetic field had a toroidal or azimuthal ring like structure and were the basis of our ALMA Cycle 2 proposal. The delivered data tell a different story. The observed polarization is more consistent with that produced by scattering from grains about 200 micron in size. However, in order to confirm this, we need observations at a different wavelength. To this end, we are proposing Band 3 observations in Cycle 4 of this same object and with the same resolution of $\sim0\farcs2$. At these longer wavelengths, we would expect less contribution from scattering and that the polarization produced will be dominated by emission from magnetically aligned dust grains. If on the other hand, scattering continues to be the dominant mechanism even at these longer wavelengths, then even larger grains of sizes of upto 500$\mu$m are present. | Disks around low-mass stars | Disks and planet formation | 2019-01-24T07:07:24.000 |
| 2315 | 2016.1.01137.S | 15 | Hot water in the inner envelope of massive proto-stars/clusters | Water controls the chemistry of many other molecular species. It is a unique diagnostic of warm gas and energetic processes taking place during star formation. Observations of water was one of the key science themes of the Herschel space mission. However within the 10-40 arcsec FWHM of Herschel, the water emission regions remain unresolved. Fortunately, some high-excitation lines of water and its rare 18O isotopologue can be observed from the exceptional ALMA high site. In particular, it will be possible to spatially resolve the hot inner envelope of massive proto-clusters in which water is evaporated from the ice mantles of dust grains. In these regions water might rival CO in abundance and, acting as a natural filter for hot gas and with its many lines of high excitation, will provide a new tool to study the inner workings of massive star forming regions, in particular their water abundances, excitation, velocity structure and morphology (disk vs. envelope components), thereby crucially enhancing the value of the water observations we obtained with Herschel/HIFI with high resolution ALMA images of optically thin and high excitation lines. | High-mass star formation | ISM and star formation | 2018-05-18T22:05:52.000 |
| 2316 | 2017.1.01489.S | 17 | Imaging the potentially self-gravitating disk around the high-mass protostar IRAS13481-6124 | In spite of its importance for astrophysics, the process through which massive stars form is only poorly understood. VLTI near- and mid-infrared interferometry by our team allowed us to resolve the AU-scale circumstellar environment around the high-mass (20 M_sun) YSO IRAS13481-6124, revealing a hot compact accretion disk around this object. Perpendicular to the disk plane, we detect a molecular outflow and two bow shocks, suggesting the presence of a collimated bipolar jet. Here, we propose ALMA Band 3 observations that will allow us to resolve the disk density structure and to construct a global radiative transfer model of the source. Our radiative transfer modeling and ATCA millimeter interferometry suggests that the disk mass might be comparable to the mass of the central object, which could result in observable self-gravition effects in the disk density structure. Combining the Band 3 data with potentially upcoming Band 7 observations will also enable us to physically characterise the detected structures, namely by determining dust opacities, separating free-free contributions, and tracing complementary line transitions. | Disks around high-mass stars | Disks and planet formation | 2019-01-26T21:54:02.000 |
| 2317 | 2019.1.01559.S | 12 | Cool accretion disk around Sgr A*. Masing of hydrogen recombination at 10,000 Schwarzschild radii. | In our previous ALMA observations, we detected a broad, 2,200km/s wide H30alpha emission from within 0.009pc of the Galactic Center black hole (SgrA*). The shape of the line and the spatial distribution indicate a rotating disk composed of ~10^4K ionized H. We constrained the amount of such gas in the accretion zone of SgrA*, which was previously unconstrained, and probed the accretion rate on intermediate accretion scales between 10 and 10^5 R_Sch. Our estimates vary between M_disk~10^{-4} - 10^{-5} Msun and dot{M}~10^{-7}-10^{-10} Msun/yr, depending on the geometrical properties of the disk and masing properties of the gas. The geometrical properties will be constrained in our scheduled Cycle 6 observation. Here we propose to constrain the physical state of the gas in the disk and its masing properties with 0.1 arcsec observations of 4 recombination lines of hydrogen: H27alpha, H28alpha, H30alpha, and H33alpha. This observation would open up an entirely new avenue to understanding the black hole environment, allowing us to perform a direct measurement of gas kinematics and initiate new observation-based modeling of the process which fuels the black hole. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2022-11-22T18:30:28.000 |
| 2318 | 2013.1.00196.S | 6 | The protosolar nebula heritage: measuring the nitrogen isotopic ratio in disks | In which forms were the chemical elements incorporated in the Solar System ? This broad topic is at the crossroads of several fields of investigation: cosmochemistry, astrobiology, and astrophysics. Because models are not able to follow the abundances of chemical species along the molecular cloud to star and planet forming sequence, this question can only be tackled observationally using ratios of stable isotopes. ALMA has the potential to revolutionize the question of our origins, by allowing us to trace our chemical history back into our parental and dispersed molecular cloud. This proposal focusses on nitrogen, a key element for terrestrial life, for which interstellar chemistry provides a consistent view of the isotopic ratios measured in embryos of star forming regions and in the protosolar nebula. Yet, one crucial measurement in the foregoing sequence is lacking, which may be key to the emerging picture of the chemical heritage of the protosolar nebula: namely, the nitrogen isotopic ratios in circumstellar disks. We propose to perform the first measurement of the 14N/15N ratio in the TW Hya disk, using CN as a carrier which is the best tracer of the bulk isotopic ratio. | Disks around low-mass stars, Solar system - Comets | Disks and planet formation | 2016-06-12T22:56:32.000 |
| 2319 | 2015.1.01271.S | 159 | Circumstellar chemistry in carbon stars: How unique is IRC+10216? | IRC+10216 is a well-studied carbon-rich star in the envelope of which, more than 80 molecules have been discovered by various line-surveys. Due to limited sensitivity, it has so far not been possible to carry out similar ranges of surveys of other carbon stars, hence we do not know how truly representative IRC+10216 is in its chemically rich composition. We propose to observe transitions of several carbon-bearing molecules, that are key stepping stones in the chemical reaction network, in the circumstellar envelopes of a sample of 7 carbon stars with different mass-loss rates and distances with ALMA in compact configuration. Comparing the spatial distributions of these molecules, and associate with stellar properties, will constrain the photochemical synthesis of longer carbon chain-bearing species in the outer envelope of carbon stars and will classify IRC+10216 within these. The proposed observations will provide crucial data towards the testing and refinement of our understanding of carbon chain chemistry for application in chemical models. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2017-05-21T11:01:44.000 |
| 2320 | 2015.1.01198.S | 35 | Detection and mapping of molecular filaments in galaxy cluster cores | The cores of galaxy clusters are very dynamic environments hosting some of the most energetic AGN in the local Universe. These two facts may be closely linked to the cooling of the hot intracluster medium fuelling AGN activity that in turn regulates the cooling, shaping the evolution of the cluster core. We propose to use ALMA (band 3, CO(1-0) mapping) to study the distribution and stability of molecular gas within the central 1' of three clusters with extended, filamentary, cold gas nebulae in their cores. Using MUSE data we will calibrate the conversion factor of L'co to molecular gas mass to accurately map the distribution of molecular gas. By measuring the kinematics of the gas to high resolution we will search for evidence of rotation or signatures of ogas flows to determine the origin and fate of the gas. Using the mass of gas and star formation rates derived from Ha emission we will map the star formation efficiency to termine the effect of creating the filaments on the star formation. The multiwavelength data available for these objects is ideally suited to compliment the ALMA observations allowing us to link the ionised and hot phases with the molecular gas. | Galaxy Clusters | Cosmology | 2017-05-28T05:01:31.000 |
| 2321 | 2019.2.00178.S | 9 | Mapping Trace Gases in Jupiter's Atmosphere | Many undetected trace species are predicted to exist in Jupiter's atmosphere, created through photochemistry, stochastic events such as cometary impacts (e.g. Shoemaker-Levy 9), or a combination thereof. Here, we seek to map five chemical species in Jupiter's atmosphere with the ACA in Band 6: HC3N, CH3CN, HNC, C3H4, and C3H8. All of these species (apart from C3H4) have yet to be definitively detected on Jupiter. The simultaneous observation of natural products of Jovian photochemistry (such as the hydrocarbons), together with species excavated from the deeper interior or distributed throughout the stratosphere by cometary impacts (the nitriles) provide insight into Jupiter's chemistry and global dynamics as a function of latitude and at the poles. The resulting brightness temperatures, spatial maps and vertical abundance profiles will be used to satisfy three objectives: a) complement the recent high resolution measurements of Jupiter's atmosphere by the Juno spacecraft; b) extend the known inventory of Jupiters trace chemical species; and c) inform our understanding of the link between Jovian photochemistry, dynamics, and the transfer of additional molecules via cometary impacts. | Solar system - Planetary atmospheres | Solar system | 2023-05-13T00:00:00.000 |
| 2322 | 2015.1.00883.S | 21 | WISE J2246-0526: An Evolving Inter-stellar Medium Hiding Beneath an Hyper-luminous AGN | With a luminosity of L_bol >= 3.5 x 10^14 Lsun mostly powered by an obscured, yet hyper-luminous active galactic nucleus, WISE J2246-0526 is the most distant Hot, Dust Obscured Galaxy (Hot DOG) discovered by WISE, and the most luminous galaxy in the Universe known to date. As part of an ALMA Cycle 2 proposal, we obtained observations of the [CII]158um fine-structure line and its adjacent dust continuum emission in Band 7 for WISE J2246-0526 at an angular resolution of ~0.32" (~2.3kpc). The ALMA data have allowed us to pinpoint the location of the bluk of the ionized gas reservoir in this unique system and study its kinematics. In this proposal we request Band 6 observations of the [NII]205um and CO (J=12-11) emission lines at an angular resolution similar to the existing [CII] data. The [NII] line will allow us to disentangle the [CII] emission that originates in dense photo-dissociation regions (PDRs) associated with star-forming structures in the host galaxy from that arising in the diffuse ionized ISM. We will also probe the warm component of the molecular gas that has been likely excited by the AGN activity via the CO (J=12-11) line. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2018-04-24T19:25:58.000 |
| 2323 | 2017.1.01521.S | 15 | Measuring the Planet Formation Potential of a 45 Myr old Low Mass Star | Planet formation is believed to occur within the first 10 million years of a stars life, when a star is still surrounded a significant mass of gas and dust. This makes the discovery of the 45Myr old M dwarf WISEJ080822.18-644357.3 a curious case; its primordial disk should have long dissipated and yet there is a strong infrared excess and active accretion, indicative of substantial remaining gas and dust. As one of three M dwarfs with active accretion within the 45 Myr Tuc-Hor region, this source may represent the typical late stage evolution of protoplanetary disks around M stars. With ALMA, we propose to use continuum and CO/13CO/C18O(2-1) observations to make the first measurement of the dust and gas mass within this system in order to characterize the planet forming potential at this late stage of evolution. | Disks around low-mass stars | Disks and planet formation | 2019-02-27T15:30:54.000 |
| 2324 | 2015.1.01460.S | 12 | Dynamical Masses of a Taurus Low Mass Star and Brown Dwarf | With ALMA observations combining high spatial and spectral resolution, we propose to observe an exceptional binary system in Taurus with two gas disks that we detected and resolved with Cycle 1 data. The binary pair is composed of a very low mass primary with a mass near the stellar limit and a faint substellar companion with a mass that may be as low as 10Mjup. These mass estimates are derived from comparison of photometry and evolutionary models, and there is a critical need to obtain empirical calibration of the evolutionary models with dynamical mass estimates. By mapping the kinematics of the two disks with ALMA, we propose to measure the masses of each component of the system and provide a benchmark calibration of the evolutionary tracks at a much lower mass than was possible previously. The mass estimate from the Keplerian motion of the companion disk will determine whether the object is genuinely planetary in mass or is an obscured more massive object. In addition to the spectral line maps, these observations yield a sensitive continuum map, from which we will compare the gas and dust disk radii and investigate the possibility of the dust disk having a sharp outer edge. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2018-04-06T18:44:00.000 |
| 2325 | 2019.1.01070.S | 11 | Tracing molecular outflows with [CI] at high redshift | Carbon monoxide (CO) is widely used as a tracer of the molecular gas in almost all types of environments. However, shocks and photoionisation from AGN radiation field may destroy CO molecules, dissociating them into atomic carbon, while leaving the underlying H2 unaffected. Therefore, neutral carbon emission may be a good, and potentially even better, alternative to CO as a tracer of AGN-driven outflows. We propose here an exploratory programme to observe the [CI](3P1 - 3P0) fine structure line in one of the most luminous QSO at z~2. If this pilot project proves to be successful at detecting and measuring the molecular outflow of the selected QSO we will extend this investigation to a large sample, by conducting the first survey of atomic carbon in a statistically-significant sample of high-z AGN host galaxies. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-01-29T21:28:35.000 |
| 2326 | 2019.1.01326.S | 293 | Localized Feedback Processes in the Galactic CMZ | Feedback is essential to describe the observed properties of galaxies. Many sources contribute to feedback, including stars, black holes, and supernovae. They release energetic photons, and inject mechanical energy, momentum, metals, and cosmic rays into their surrounding ISM. This dramatically influences the star formation efficiencies. The Central Molecular Zone (CMZ) of our Galaxy hosts some environments with dramatic feedback, like the star forming region Sgr B2 and the supermassive black hole Sgr A*. In addition, there are many less studied regions where the ISM is clearly energized by some process and the combination of those small scale regions may substantially contribute to the overall CMZ feedback processes. From our unique CMZ molecular gas temperature maps, we select eight regions with substantially increased temperature. These regions show a mix of elevated turbulence, SNe and WR stars. We propose to map the ISM in 12'x12' regions around eight of these hot spots with the ACA in a number of molecular lines. These data will trace the localized impact of feedback through measuring shocks, PDRs, elevated excitation, and through a detailed dynamical analysis. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2021-07-02T15:08:01.000 |
| 2327 | 2018.1.00513.S | 19 | An explosive outflow in G5.89-0.39: Evidence for a (proto)stellar merger? | This cycle 6 ALMA proposal aims to confirm the presence of the 3rd explosive outflow known in the Galaxy related with the massive and luminous star forming region G5.89-0.39, possibly related with a massive protostellar merger. The recent analysis of SMA submillimeter CO(J=3-2) observations revealed a few explosive filaments with clear Hubble-velocity laws as those mapped in Orion-KL and DR21. These signatures are similar to those found in Orion-KL, where SMA observations revealed about 30 expanding filaments associated with this explosive outflow and recent ALMA observations confirmed its explosive nature with more than 150 molecular filaments (Bally et al. 2017). ALMA sensitive observations will likely confirm the explosive nature of G5.89-0.39 with the detection of many faint filaments. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2021-01-23T13:28:45.000 |
| 2328 | 2021.1.01098.S | 28 | The clump-scale ISM in gravitationally unstable discs at z~0.1 | It is still unclear what drives strong star formation and turbulence in high-z disc galaxies that appear to be clumpy and gravitationally unstable. Observing molecular gas at clump scales is key to answer this question. However, resolving clumps in high-z galaxies has been largely limited to low resolution at ~1kpc scale. We thus propose here high-resolution (~0.1" or ~200pc) ALMA CO(2-1) observations in two local gravitationally unstable discs at z~0.1, that show many similar properties to high-z disc galaxies. We aim to (1) link clump-scale ISM properties and gas turbulence to global-scale disc dynamics; (2) measure the SF law at clump scale and quantify the star-formation efficiencies of individual clumps and (3) test whether gas turbulence and star formation are induced by clump collisions driven by gravitational instability. We have developed a new model to quantify effects of clump collisions on clump properties and gas turbulence in a gravitationally unstable disc. If our collision model does indeed apply to our targets, then a number of interesting general conclusions about high-z disc galaxies can be drawn from our model. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-08-16T23:05:12.000 |
| 2329 | 2016.1.01223.S | 8 | Emissoin and absorption of CO gas: a study of the distribution of warm molecular gas nearby AGNs | Studying the structure and physical properties of so-called molecular tori, which obscure active galactic nuclei (AGNs) and supply them with mass, is important in order to understand the activity of AGNs and its effect on galaxy evolution. We propose high spatial resolution 12CO(6-5) mapping observations with ALMA within central 10-pc regions of AGN host galaxies that show strong high-J CO rotational emission lines, namely NGC 4418, NGC 34, IRAS F17207-0014, and IRAS F05189-2524. These galaxies have similar CO rotational spectral line energy distributions (SLEDs), but exhibit different optical depths of CO ro-vibrational absorption in the near-infrared region. We suppose that this difference reflects innermost geometry of a dust sublimation layer and warm molecular gas. The proposed high-spatial-resolution observations are expected to provide us with the information on the innermost geometry when discussed with the strength of the near-infrared absorption. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-08-11T05:26:58.000 |
| 2330 | 2016.1.01523.S | 7 | SMG Dust Heating - Star-formation versus AGN via an ALMA survey of the WHDF | We propose to test the hypothesis that bright sub-mm galaxies (SMGs) are powered by obscured AGN. We shall do so by measuring the angular size of seven SMGs at the highest S/N and resolution so far achieved at our faint 3.3mJy flux limit. We target a complete sample from LABOCA observations of the William Herschel Deep Field. Five of these SMGs are X-ray quiet and two are identified with luminous absorbed X-ray QSOs at z~2. Our aim is to use exquisite ~0.1'' ALMA resolution to determine if any of these SMGs are still unresolved at ~ 500 kpc scales, which is the expected size of AGN powered cool dust tori. The two X-ray quasars will act as a control sample for the other five SMGs allowing a direct comparison of the resolvability between the two classes. If the SMGs are resolved then it would strongly suggest a star-forming origin for the sub-mm background and our S/N will also allow us to detect clumpy structure. If the X-ray quiet SMGs are resolved and the X-ray loud are not then it will suggest SMGs comprise two different sub-populations, AGN and star-formation dominated. This or any other outcome is guaranteed to reveal further the nature of the sub-mm and X-ray backgrounds. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-02-17T10:53:29.000 |
| 2331 | 2016.1.01404.V | 0 | Imaging the Shadow of a Supermassive Black Hole: Event Horizon Telescope Observations of Sgr A* | The Galactic Center supermassive black hole, Sagittarius A* (Sgr A*), subtends the largest angular size of any black hole in the universe and is now within the reach of direct imaging with very long baseline interferometry (VLBI). Observations with the Event Horizon Telescope (EHT) have shown that the 1.3mm emission from Sgr A* occurs within ~5 Schwarzschild radii of the black hole (Doeleman et al. 2008), but these observations have lacked the sensitivity and baseline coverage to produce images of the emission. We propose Band 6 observations of Sgr A* with ALMA joining the EHT. These observations will produce the first images of a black hole with event-horizon-scale resolution, sufficient to detect distinctive signatures of strong-field gravity such as the "shadow" cast by the supermassive black hole on hot surrounding plasma. They will also produce images of the magnetic field structure near the black hole and will open a new regime of time-domain studies of Sgr A*, allowing us to study a black hole "feeding" in real-time over many orbital periods. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-10-21T09:39:23.000 |
| 2332 | 2019.1.00763.L | 336 | VERTICO: The Virgo Environment Traced in CO | The Virgo Environment Traced in CO survey (VERTICO) is a pioneering large program that will investigate the effect of environment on molecular gas by mapping the distribution and kinematics of CO(2-1) in a representative sample of 51 spiral galaxies (36 this proposal + 15 archival) in the Virgo Cluster using the Atacama Compact Array (7m + Total Power). VERTICO will reveal the physical mechanisms that drive galaxy evolution in dense environments in unmatched detail, and provide the critical final component of a diverse, homogeneous legacy data set for studying galaxy evolution science in the closest galaxy cluster. Our key science goals all require deep, high-resolution maps of cluster galaxies' molecular gas content which do not exist in current surveys. With these data, VERTICO will open up new avenues of discovery by: 1. Quantifying environmental effects on the structural and kinematic properties of molecular gas, as well as the atomic-to-molecular gas ratio in Virgo galaxies 2. Establishing the star formation rate-molecular gas surface density and dust-to-gas relationships on sub-kpc scales throughout the Virgo Cluster | Surveys of galaxies | Galaxy evolution | 2021-04-21T20:35:23.000 |
| 2333 | 2019.1.00014.S | 22 | Direct imaging of the multi-phase AGN torus of the Circinus galaxy | The nearest type-2 AGN, the Circinus galaxy, shows a pc-scale polar-elongation of warm dust at its center, which contradicts the classic torus paradigm. Recently, we proposed that the radiation-driven fountain model can naturally reproduce this intriguing feature. This model was tested by ALMA Cycle 4 observations of CO(3-2) and [CI](1-0) with 5 pc and 14 pc resolutions, respectively. We found a hint of a difference between the molecular gas dynamics (or geometry) and atomic gas dynamics at the central ~5 pc region, which seems to be driven by atomic outflows (and failed winds) as expected in our model. However, the limited resolutions have not allowed us to fully resolve that intriguing region. Thus, we now request 2 pc resolution mappings of these two lines to clearly delineate the multi-phase structures directly. We also expect to see outflows with [CI](1-0), at above the mid-plane of the disk. The results will be compared with our dedicated simulation for the Circinus to test the model. Our observations will reveal the multi-phase geometrical/dynamical nature of the circumnuclear region, which will explain the long-lasting mystery, the physical origin of the AGN torus. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2021-02-15T14:00:36.000 |
| 2334 | 2021.1.01123.L | 236 | exoALMA | Detecting planets embedded in their natal protoplanetary disk is essential if we are to understand the phenomenal diversity found in the properties of mature exoplanets. Recent results have shown that ALMA is uniquely capable of detecting a population of these embedded planets by revealing strong, localized deviations in the gas velocity structure driven by the embedded planet. Here, we propose a groundbreaking Large Program to undertake the first sub-mm planet hunting campaign. We request 100 mas resolution observations of 12CO (3-2), 13CO (3-2) and CS (7-6) line emission at a ~26m/s velocity resolution for 15 sources identified as those most amenable for the detection of planets. 3D hydrodynamical simulations of planet-disk interactions have shown planets excite an extensive family of kinematic features (spiral arms, meridional flows and circumplanetary rotation), enabling strong constraints on the planets mass and on its immediate environment. These observations will provide the most comprehensive study of the physical and dynamical structure of protoplanetary disks to date, providing a rich legacy dataset for the study of the planet formation process. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2022-11-18T20:22:39.000 |
| 2335 | 2022.1.01187.S | 0 | Imaging the magnetic field structures within 20 au around the young protostar B335 | We propose to observe the 0.9 mm polarized continuum at a 0.04"-0.06" (6-10 au) resolution in the protostar B335. We aim to reveal the magnetic field structures within 20 au around the central disk+star system, which are shaped by the competition between the gravity, angular momentum, and magnetic field strength. From the ALMA 1.2 and 0.9 mm polarization data at resolutions of 0.2"-0.7" (30-70 au), we found that the polarization percentage is higher at the longer wavelength in the innermost envelope on a 100 au scale, inconsistent with the expected trend for the scattering-induced polarization. In addition, the ALMA high-resolution (0.04"-0.05") 0.9 and 1.2 mm continuum data shows that the 0.9 mm continuum emission is optically thin with a large spectral index of 3.3 and a brightness temperature lower than 30 K at a radius of 20 au in B335. No sign of scattering-induced polarization and the optically-thin continuum emission make B335 an excellent target to investigate the magnetic field in the innermost 20 au region in a protostellar source. With this project, we will study the effects of the small-scale magnetic field on the disk structure, mass accretion, and outflow launching. | Low-mass star formation | ISM and star formation | 2025-03-16T15:33:24.000 |
| 2336 | 2018.1.01347.S | 165 | Is it raining over hub-filament systems? | Although filaments appear to be ubiquitous structures within molecular clouds, their formation mechanism is far from well understood. In a scenario of global, multi-scale gravitational contraction of molecular clouds, main filaments gain mass from the surrounding material, which rains onto them through perpendicular smaller elongated structures, called 'striations'. With this proposal we aim to test this scenario by studying the kinematics of the gas surrounding main filaments at different spatial scales, hence requiring high sensitivity and angular resolution together with the use of ACA, a performance which can only be achieved with ALMA. We propose to perform a mosaic using low- and high-density gas tracers of a well-studied infrared dark cloud, IRDC G14.2, consisting of two prominent hub-filament systems. By investigating the kinematical imprints of the gas, we will be able to discriminate between the turbulent and global multi-scale gravitational contraction scenarios of filament formation as the velocity field is expected to be different. These ALMA observations will constitute a crucial test for basic theories of molecular cloud dynamics and filament formation. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-06-19T12:10:47.000 |
| 2337 | 2019.2.00034.S | 63 | Resolving systematics in the Planck sub-millimetre spectra of radio-loud AGNs | We have found the possible dust contamination as denoted by the sub-millimetre excess in the radio spectra of bright AGNs observed during the Planck campaign. The origin of the dust in most cases seem to be intrinsic as they are unaffected by the Galactic dust. A majority of sources in the sample showing this trait are blazars, which as per the definition are old ellipticals with no significant traces of dust. The SEDs of these sources seem to be unlike the starburst galaxies that are known to have higher gas/dust temperatures. We propose continuum observations of the dust emission in 16 AGNs. Our goal is to characterise the nature and origin of the sub-mm flux in terms of the particle acceleration in addition to the dust in these objects and re-visit the evolutionary stage of AGNs in elliptical galaxies. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-10-05T10:06:47.000 |
| 2338 | 2018.1.01334.S | 25 | Carbon physics across the molecular cluster medium in 4C 41.17 (z=3.8) | The evolution of galaxies is tightly linked to processes in the circum- and inter-galactic medium (CGM/IGM). However, a direct connection between the CGM/IGM and the stellar growth of massive galaxies has remained missing, because we had yet to identify the ultimate reservoir of cold halo gas that has sufficient mass to fuel widespread star-formation. Recently, we mapped -for the first time- a widespread reservoir of cold molecular gas across the ~100 kpc halo of the massive Spiderweb Galaxy at z=2.2. This provided the first direct link between in-situ star formation and molecular gas in the IGM at high-z. We here propose observations of [CI] 3P1-3P0, [CI] 3P2-3P1 and [CII] in the only other forming massive cluster-galaxy with properties matching those of the Spiderweb, namely 4C41.17 at z=3.8. We will map the carbon cycle at scales ranging from the individual merging galaxies to the cluster-IGM, in order to study the molecular gas content, energy budget, and star-forming properties of the IGM. Our results will provide unique information about the role of very extended molecular gas and the history of star formation at a crucial epoch of massive galaxy evolution (z = 2.2 - 3.8). | High-z Active Galactic Nuclei (AGN), Galaxy Clusters | Active galaxies | 2020-11-01T00:00:00.000 |
| 2339 | 2016.1.01344.S | 17 | Multi-wavelength imaging of the possibly planet-induced asymmetries in a pre-transitional disc | Scattered-light imaging of several transitional discs revealed intriguing spiral-arm structures that might be tell-tale signs of planet formation. However, it is not clear whether these structures correspond to significant surface density enhancements, or whether they are minor surface scale-height perturbations. Here we propose Band 7 observations on the pre-transitional disc of V1247Ori, where our recent SEEDS polarimetric imaging revealed an one-armed spiral-arm structure on scales of 200-300mas. As follow-up observations of our Cycle 3 project, our ALMA imaging aims to (a) determine the azimuthal density-contrast in dust continuum, (b) search for streamers and emission from the putative planet, (c) trace gas spatial distribution and kinematics. | Disks around low-mass stars | Disks and planet formation | 2018-09-28T13:30:32.000 |
| 2340 | 2018.1.00141.S | 39 | Where is 13CH+ in disks? A first detection from the ground. | CH+ was one of the first molecules found in the interstellar medium and is a ubiquitous and important species, initiating a chain of reactions that lead to common molecules like CO, HCN and CN. Yet its formation mechanism is not well understood. Rotational CH+ transitions have been detected in protoplanetary disks using ISO and Herschel, but it is unclear where the gas is located - in the inner hot region or the outer cool envelope. One suggestion is that the main formation mechanism involves vibrationally-excited H2, in which case we have shown the emission could arise in the outer disk. We propose the first ground-based observation of a disk in CH+ (through its' isotopomer 13CH+). The line profile will identify the location of the gas, and hence inform models of the formation of this key molecule in disk chemistry. | Astrochemistry | ISM and star formation | 2020-09-13T20:27:02.000 |
| 2341 | 2019.1.00203.S | 20 | Sub-percent constraint on the molecular gas mass fraction of a massive, quenched galaxy at z=2 | A major puzzle in galaxy evolution studies is how massive galaxies quench their star formation. The cold gas content can discriminate between various quenching mechanisms. Despite multiple efforts to detect molecular gas in massive quenched galaxies (MQGs) at z>1, there is no single detection to date, suggesting significant molecular gas depletion. We propose to place the deepest molecular gas constraint in the most luminous MQG at z=2. This will conclusively determine whether quenching is due to a lack of molecular gas or inefficient star formation. Thanks to the remarkable lensing magnification and high intrinsic stellar mass of our target, it is our only chance to reach a sensitivity comparable to the emission of z~0 MQGs with current facilities. Targeting the CO (4-3) line and Band 7 dust continuum, we will: (1) obtain 2 independent measurements of the H2 mass to constrain its gas fraction down to 0.5%; (2) measure its star formation efficiency and depletion timescale. Such a deep observation is pivotal in interpreting the non-detections reported in the literature. The results will inform the feasibility of future ALMA surveys of quenched galaxies. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2021-03-18T19:36:47.000 |
| 2342 | 2018.1.00982.S | 163 | Star formation in the tidal tail of NGC 4254 in the Virgo cluster | We propose to map in the 12CO(1-0) line a region of 6'x4' in the south-west of the galaxy NGC 4254, outside its optical disc, and characterised by several compact regions of star formation. These HII regions, detected in very deep narrow-band Halpha images obtained during the complete Virgo cluster survey VESTIGE, have been formed after a rapid flyby encounter of this massive galaxy with another Virgo cluster member. The analysis of the stellar populations of these compact regions done using SED fitting codes based on a unique set of multifrequency data, from the far-UV (GALEX) to the far-IR (Herschel), indicate that star formation has abruptely ceased in some of them. The molecular gas data will be used to study the relationship between gas column density and star formation activity in extreme environments (cold gas clouds surrounded by a hot intracluster medium) with the purpose of understanding the fate of the stripped material in high density regions. This analysis will shade light on the origin of the diffuse intracluster light observed in clusters, as well as on that of compact unbound sources such as ultra compact dwarf galaxies. | Merging and interacting galaxies | Galaxy evolution | 2020-08-14T22:11:39.000 |
| 2343 | 2022.1.00139.S | 0 | Measuring the magnetic field through CN Zeeman effect in G31.41+0.31 | ALMA capabilities have allowed major advances in the understanding of star and planet formation, but up to now, the Zeeman splitting detection, which is the only way to directly measure the magnetic field strength, has been elusive. Here we propose to observe the Zeeman effect of CN and SO with ALMA in one of the best and most favourable cases, the high-mass star-forming core G31.41+0.31 (G31). The combination of previous ALMA dust polarization observations and modelling has properly constrained the magnetic field configuration in this massive core. The magnetic field strength derived from the indirect statistical method is well above the current detection limit for ALMA circular polarization, and offersa rare opportunity for Zeeman observations. Because different species may trace different excitation conditions, by revealing Zeeman splitting in both line absorption and emission, this proposal promises a full picture of the B-field strength over the whole core for the first time. This study will pave ways for future Zeeman measurements in other star-forming cores. | High-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 2344 | 2021.1.01324.V | 0 | Testing the binary black hole model for OJ287 with the EHT+ALMA | We propose EHT+ALMA observations of the blazar OJ287, the only known candidate for harboring a nano-Hertz gravitational wave emitting sub-pc supermassive binary black hole system (SMBBH). The improvement in the north-south resolution and sensitivity provided by ALMA, together with the addition of three new EHT stations (GLT, Kitt Peak, and NOEMA), and the twice wider bandwidth will significantly boost the EHT+ALMA image capabilities as compared with previous 2017 observations. This, together with the projected separation of the binary system of 14 uas (~40% larger than in previous 2017 observations) provides a unique opportunity to either spatially resolve the binary system for the first time with our proposed 2022 EHT+ALMA observations, or to establish a tight upper limit for the orbital separation that could eventually rule out the binary system scenario in favor of alternative models, such as the presence of a tilted accretion disk that can also explain the observed swing of the innermost jet structure and periodicity in the light curves. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-05-02T21:25:18.000 |
| 2345 | 2019.1.00447.S | 27 | Mapping multi-phase outflows in three nearby z~2 galaxy analogs | Galactic winds are ubiquitous in star-forming galaxies at z>1, and star formation feedback is now a fundamental component of star formation theory and galaxy evolution models. However, only a few galaxies with outflows at z>1 have been observed in CO, and there are no cases where the multi-phase properties (molecular, atomic, ionized) of high-z outflows is known. Due to this severe lack of data, fundamental properties of outflows (size, mass, etc) are poorly constrained, and a key quantity the mass outflow rate remains uncertain at the order-of-magnitude level. Because we do not have a full description of outflowing gas we still do not have a full picture of the evolution of star forming clumps in z~2 galaxies. The key missing piece of information is the outflowing molecular gas. We propose to map in CO(3-2) line emission the star-formation driven outflows at 1 kpc resolution in 3 galaxies at z~0.1 from the DYNAMO sample. Our clumpy, gas-rich target galaxies are identical in properties to typical systems at z~2. By combining in hand Keck data with the proposed ALMA data we will obtain the first measurement of the full multi-phase outflows from these intense star forming regions. | Galaxy structure & evolution | Galaxy evolution | 2021-01-16T15:35:05.000 |
| 2346 | 2017.1.01472.S | 17 | Exploring the diversity in the host galaxies of the most luminous quasars at z~7 | Redshifts beyond 6.5 represent the new frontier for quasar discovery. Using state-of-the-art data from the Dark Energy Survey and VISTA we have recently identified 3 of the most luminous quasars known at z~6.5-7, with comparable luminosity to the z=7.1 quasar ULASJ1120. Our discoveries include the second most distant quasar and second most luminous quasar at such high redshifts. Compared to previously known z>6.5 quasars, our new quasars span a wider range in spectral energy distributions and ionized near-zone sizes suggesting significant diversity in both the environments and ages of the quasars at fixed luminosity and redshift. The proposed ALMA observations will, for the first time, explore whether this diversity is mirrored in the properties of the quasar host galaxies. In particular, we will detect [CII] emission and the far infrared dust continuum and observe the CO(7-6) and [CI] transition to quantify the star formation rate, dynamical and molecular gas masses of the quasar hosts. By comparing to previous observations of the host galaxies of high-redshift quasars, we will examine the full range in host galaxy properties of the earliest supermassive black holes. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-11-22T16:26:32.000 |
| 2347 | 2013.1.00366.S | 6 | A 3-Dimensional View of Protoplanetary Disk Turbulence | Turbulence is a central component of planet formation theory, yet observational constraints on its magnitude and spatial distribution have so far been scarce. Millimeter-wavelength spectroscopy of molecular lines at high spectral resolution represents a promising method of constraining nonthermal linewidths in protoplanetary disks. Here we propose to measure vertical and radial variations in turbulent linewidth to measure the three-dimensional distribution of turbulence in a disk for the first time. We will simultaneously observe three molecular lines at 0.5" resolution: optically thick and bright CO(2-1) probes the disk surface and vertical temperature gradient, optically thin C18O(2-1) traces the bulk of the warm molecular layer, and DCO+(3-2) traces the planet-forming midplane. The 0.5" spatial resolution breaks several crucial spatial scales in the disk, and the spectral resolution will resolve below the measured turbulent linewidth. For the first time, we will plausibly resolve, or place the first interesting constraints on, the MHD "dead zone" that is a signature prediction of MRI turbulence theory. | Disks around low-mass stars | Disks and planet formation | 2015-10-07T13:54:10.000 |
| 2348 | 2012.1.00602.S | 1 | Shedding light on the completion of reionization by ALMA [CII] Observations | We propose [CII] line observations for high-z Ly$¥alpha$ emitters at $z = 6.5$ and $5.7$ with Band 6 and 7 to estimate a reliable $x_{HI}$, and reveal when the reionization completes. In the past, the volume-averaged neutral hydrogen fraction, $x_{HI}$, has been estimated from evolution of Ly$¥alpha$ luminosity function and Ly$¥alpha$ escaping fraction, $f_{esc}^{Ly¥alpha}$, with Ly$¥alpha$ emitters (LAEs) and Lyman break galaxies (LBGs) in conjunction with theoretical models. These observations have indicated that $x_{HI}$ increases from $x_{HI}=0$ at $z=5.7$ to $0-0.4$ at $z=6.5$, but the large uncertainty of $x_{HI}$ estimates raised by model parameter choices is too large to conclude that the reionization completes between $z=5.7$ and $6.5$. Based on our [CII] observations by ALMA, we will evaluate $x_{HI}$ by the following two approaches. One is to estimate a velocity offset ($¥Delta v$) between the systemic velocity and Ly$¥alpha$ line of LAEs. The $¥Delta v$ value is a key parameter in the theoretical models. The observed [CII] line profile will give us a systemic velocity. Combining the available Ly$¥alpha$ velocity, we will obtain $¥Delta v$. The second is to estimate $f_{esc}^{Ly¥alpha}$ from a [CII] luminosity, $L_{[CII]}$. Using $L_{[CII]}$, we will estimate $f_{esc}^{Ly¥alpha}$ independent of theoretical assumptions such as dust extinction. By combining these two approaches, we will be able to estimate $x_{HI}$ more accurately, and identify the epoch of the reionization completion. In contrast to related proposal of Ouchi et al. that aims to measure $x_{HI}$ at the heart of the reionization era ($z=7.3$), our program will specify the epoch of reionization completion based on the observations of two key epochs ($z = 5.7$ and $6.5$) that are probably near the end of reionization. Our Band 6 and 7 observations will provide not only our [CII] line observations, but also 1.2mm and 1.1mm continuum emission, respectively. These continuum emission will be used to evaluate dust extinction of LAEs that will doubly check the validity of our $x_{HI}$ estimates and reveal the dust properties of LAEs. Our observations by ALMA will make a breakthrough to determine the epoch of reionization, and bring new insights on properties of LAEs. | Lyman Alpha Emitters/Blobs (LAE/LAB), Galaxy structure & evolution | Galaxy evolution | 2015-02-04T04:43:00.000 |
| 2349 | 2021.1.00285.S | 5 | An ALMA view of the MUSE Ultra Deep Field | We propose to map the MUSE Ultra Deep Field with ALMA to uncover dusty and highly star-forming galaxies and study their contribution to the cosmic enrichment. With 300 hours of MUSE and HST imaging and spectroscopy, the MUDF provides an extremely deep survey of the unobscured galaxy population in a strategic field where a z~3.22 quasar pair enables a unique study of how dust-free galaxies correlate with the intergalactic gas. ALMA will complete this picture and enable an unbiased study of the cosmic enrichment by galaxies across the full range of star formation, stellar and dust mass. By uncovering obscured sources near a large overdensity at z~3 with tens of galaxies and two quasars, ALMA will also reveal how the link between galaxies and the intergalactic gas changes in dense environments. Finally, ALMA will map via emission lines the cold ISM of tens of galaxies together with their halo gas as mapped by quasar absorption. Altogether, ALMA observations in the MUDF will provide an exceptionally deep and multi-wavelength dataset to finally address the key question of how galaxies of different physical properties contribute to the cosmic metal enrichment in different environments. | Lyman Alpha Emitters/Blobs (LAE/LAB), Damped Lyman Alpha (DLA) systems | Galaxy evolution | 2023-06-09T11:33:07.000 |
| 2350 | 2017.1.01708.S | 28 | Study of asymmetric outward motion in the O-rich AGB stars V1111 Oph and WX Psc | We perform a detailed study of the radial structure and kinematics of the innermost region of Mira variable V1111 Oph and OH/IR star WX Psc in order to investigate the development of asymmetric outward motions from SiO maser region to 22 GHz H2O maser region using the ALMA high angular resolutions of ~ 20 mas in Band 6. The ALMA observation data of SiO v=1, 2, J=5-4 masers, 28SiO, 29SiO v=0, J=5-4 thermal, H2O v2=1 (232.6 GHz) and continuum emission will be compared with the astrometrically registered maps of SiO (J=1-0, J=2-1, J=3-2) and 22 GHz H2O masers toward V1111 Oph and WX Psc by the Korean VLBI Network (KVN). We also provide good constraints on the stratification of the extended atmosphere for the temperature and density etc. combining the KVN monitoring data at millimeter wavelength with the ALMA Band 6 data at sub-millimeter. In addition, the radiative transfer model of H2O and SiO spectra will be developed based on existing non-local radiative transfer model and combined dynamic atmosphere and maser propagation model. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-02-28T20:35:49.000 |
| 2351 | 2013.1.00287.S | 50 | Investigating the formation of isolated high-mass stars in the LMC | High-mass stars usually form in giant molecular clouds (GMCs) as part of a young stellar cluster, but some isolated O/B stars are observed. What are the initial conditions that lead to the formation of these objects? The aim of the proposed observations is to measure the distribution and basic physical properties of the neutral gas associated with 12 isolated intermediate- and high-mass young stellar objects (YSOs) in the Large Magellanic Cloud. We have identified and confirmed the YSOs using Spitzer IRAC photometry and IRS spectroscopy, and single-dish CO observations by our team put upper limits between a few thousand and 10,000 solar masses on their associated reservoir of molecular gas. Here we propose observations of the 1-0 and 2-1 transitions of the main CO isotopes in order to measure the density, temperature and velocity structure of the CO clouds associated with the YSOs and, for a subset of sources, CI observations to investigate the distribution of the neutral gas components without CO emission. The observations will provide the basic empirical measurements that are required to develop a theory for isolated high mass star-formation. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2016-10-05T08:21:48.000 |
| 2352 | 2018.1.00770.S | 74 | How does a filament fragment? A case study in Orion B | The evolution of filaments into prestellar cores is a poorly understood step of the star formation process. Although various substructures have been identified in active, core-forming filaments, such as longitudinal fragments created by gravitational instabilities, and velocity-coherent fibres, the mechanisms driving the evolution of filaments and the formation of cores are unknown. This is why we propose to observe a specific filament in the Orion B molecular cloud. The filament shows longitudinal fragmentation, and its velocity structure suggests the presence of unresolved fibres; the fragment dimensions are comparable with those detected in more active regions such as Orion A or Taurus. However, this Orion B filament is devoid of dense cores and YSOs - which suggests it is in its earliest stages of evolution towards the formation of dense cores. We aim at characterizing at high angular resolution the filament's structure, in particular its fibres. By comparing it with more actively star-forming regions, we aim at understanding the process by which a complex and filamentary but quiet region such as Orion B can become actively star-forming. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-07-15T14:01:13.000 |
| 2353 | 2013.1.00156.S | 18 | Dust nucleation in oxygen-rich envelopes of two evolved stars, VY CMa & Mira | Although dust plays a vital role in many astrochemical processes, its formation taking place around dying stars remains elusive. In particular, it is not understood how inorganic (non-carbonaceous) stardust is produced. The current nucleation theories predict that the first clusters (seeds) are formed from refractory oxides of Ti and Al, but these species remained undetected until very recently. We propose observations in which ALMA will spatially resolve the emission of TiO, TiO2, and AlO, which are the most important gas-phase species preceding the formation of seeds. The proposed observations will provide a direct view on the dust nucleation process in oxygen-rich stars. Two objects in which we have already detected the metal oxides will be observed: a red superiant, VY CMa, and an AGB star, Mira. They are prototypes of the high- and low-mass stars at the end stages of their evolution. In 6.9 h of total observing time, we will not only address the urgent questions about dust nucleation, but also shed more light on the mass-loss mechanism in late-type stars and solve some of the long standing problems about the nature of VY CMa, Mira and its companion. | Evolved stars - Chemistry | Stars and stellar evolution | 2016-11-02T23:14:38.000 |
| 2354 | 2012.1.00661.S | 0 | Properties of the interstellar medium around the supermassive black hole at the centre of the radio galaxy M87 | The archetypal giant elliptical galaxy at the centre of the Virgo cluster, M87 (3C 274), is a unique object in which to study the origin and properties of the interstellar medium (ISM) in a radio galaxy located in a dense environment. CO J=1-0 emission from the molecular gas in the inner part of M87 has been detected with the IRAM-30m telescope, and the molecular gas likely resides in a circumnuclear disk-like structure. While a very well-known object across most of the electromagnetic spectrum, M87 still lacks a detailed study in the (sub)millimeter range, requiring an advance in both sensitivity and angular resolution. The unique ALMA Cycle 1 capabilities will allow us to make the first detailed investigation of the properties of the ISM around the supermassive black hole at the centre of M87. We wish to use bands 3 and 7 to map the CO J=1-0 and CO J=3-2 lines, respectively, to trace the bulk of the molecular gas and the warmer denser gas, and in addition image the continuum emission, at an angular resolution of 1 arcsecond (~80 pc). Such observations are not currently possible with any other facility and will dramatically improve our knowledge of this archetypal radio galaxy. With a small investment of ALMA time we will achieve the deepest and highest spatial resolution image yet of the molecular gas content and excitation of a giant elliptical galaxy. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2016-03-23T14:04:56.000 |
| 2355 | 2017.1.00717.S | 99 | Astrochemical ABCs - An ALMA Band 9/10 Chemical Survey of NGC 6334I | Recent ALMA observations by the proposers have revealed that the massive star-forming region NGC 6334 I is one of the richest and most diverse sources of chemical complexity in the galaxy, and may very well turn out to be a hot spot in the molecular universe. ALMA Band 7 observations indicate the presence of a variety of physical sources across evolutionary stages, including several hot cores. Here, we propose to leverage the power of ALMAs Band 9 and 10 receivers to operate in dual side band mode to conduct a full Band 9 and a pilot Band 10 astrochemical survey of this region with relatively modest time requirements. The resulting spectra will provide insight into the chemical differentiation by probing simple, light species not readily accessible at lower frequencies, rigorously constrain the excitation of complex organic molecules with a higher-energy anchor to existing lower-frequency data, and dig into the inner reaches of the brightest hot core with high-excitation probes of physical conditions. The resulting spectral line surveys will be made publicly-available. | Astrochemistry | ISM and star formation | 2019-04-20T13:54:03.000 |
| 2356 | 2018.1.00750.S | 30 | Resolving the inner wind and exposing a potential companion of the AGB star EP Aquarii | High-resolution observations of dust-driven AGB winds show that their global morphologies are often highly non-spherical. We observed the oxygen-rich AGB star EP Aquarii with ALMA cycle 4, and found that its inner wind region reveals a prominent spiral structure in CO. At the base of the spiral structure (0.5'' = 65 AU at 135pc), the SiO emission exhibits a local emission void, which strongly suggests that the spiral in EP Aqr is caused by a dim binary companion. To complement our cycle 4 observations, we request cycle 6 observation of the inner 5'' by 5'' of the wind of EP Aqr at a resolution of 20 mas. This will allow us to properly resolve spiral-launching zone, and reveal the true nature of the potential companion of EP Aqr. This will ultimately enable us to investigate the impact of binarity on the overall wind morphology, expose the link of these phenomena to the shaping of the large scale outflow, and pave the way to improved mass-loss prescriptions for AGB stars. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2020-10-30T16:47:59.000 |
| 2357 | 2017.1.01571.S | 33 | How an obscured quasar loses its natal cocoon: the case of PKS 1549-79 | We propose to search for and characterize the molecular outflow in PKS1549-79, one of the closest young, radio-loud quasars still enshrouded in its natal cocoon. The cocoon is heavily disturbed by the energy released by the active nucleus as shown by a spectacular outflow seen in [OIII]. However, the energy associated to the outflow of ionised gas is only a small fraction of the available accretion power, in contrast to what expected from quasar feedback models. With the proposed observations we will explore whether, as found in other objects, much of the outflow is instead tied up in the molecular phase of the ISM. We propose to observe CO(2-1) and CO(3-2) with 0.07" resolution to search for the molecular outflow. We expect these lines to be bright, given the expected high excitation temperature and the likely optically thin conditions. The high spatial resolution will allow to identify the location of the outflow relative to the radio source and whether it is driven by the radio jet. This project is part of our on-going effort to characterize the impact of radio jets in different phases of their evolution and to provide a reference point for similar studies at high redshift. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-02-22T19:44:31.000 |
| 2358 | 2019.1.00713.S | 5 | Study of the earliest phases of a Super Star Cluster (SSC) formation in the starburst ring of NGC 1068 | We have used 0.4" ALMA images of the HC3N vibrational excited emission (HC3N*) to reveal the first Super Hot Core (SHC) in the starburst ring of the nearby Seyfert 2 galaxy NGC 1068. Associated to Super Star Clusters (SSCs), HC3N* emission is a direct probe of unobscured mid-IR emission since it is radiatively pumped by dust heated by the protostars. The SHC is unresolved, has a temperature ~300 K, a large apparent luminoty few 10^10 Lsun and is likely tracing the earliest phases of a SSC, just before massive stars ionize their surroundings. However, our estimates are still very rough and higher angular resolution and sensitivity are required to make robust estimates of its properties. We propose to image the HC3N* emission in the SHC with a 0.023-0.046" resolution and enough sensitivity to make accurate measurements of its size, temperature, mass and luminosity, and to derive its temperature and density profile. This data will provide unique information on how SSC form and the effect of the feed back from the AGN on star formation at scales of kpcs. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2022-10-06T23:07:50.000 |
| 2359 | 2016.1.00426.S | 33 | An in-depth study of Pluto's atmosphere | Pluto' tenuous and time-changing atmosphere is unique in the Solar System, being the place of both Mars-like climatic cycles and Titan-like chemistry. Our ALMA Cycle 2 observations yielded a strong detection of both CO and HCN in this atmosphere, revealing (i) a well-characterized, but difficult to explain, temperature decrease in the middle atmosphere from ~50 km to ~400 km altitude (ii) an extremely strong supersaturation of HCN in the upper atmosphere (>500 km). We now want to address in more details the thermal field, dynamics and chemistry of Pluto's atmosphere. First we will spatially resolve (~0.060 arcsec, C40-7) the CO and HCN emissions, in order to: (i) constrain the horizontal atmospheric temperature distribution, (ii) investigate latitudinal and diurnal variability of HCN, and (iii) search for putative winds in the upper atmosphere. Second, we will investigate atmospheric chemistry by searching for two as yet undetected species, namely HNC and CH3CN. The detection of HNC, anticipated from our photochemical model calculations, would provide key evidence for the existence of Titan-like ion-chemistry in Pluto's atmosphere. ALMA is unique for all these goals. | Solar system - Planetary atmospheres, Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2018-09-05T16:07:12.000 |
| 2360 | 2022.1.00738.S | 71 | Water masers and the hidden nature of Compact Obscured Nuclei | In recent years, observations of vibrationally excited HCN emission have revealed the presence of extremely compact, dense and obscured nuclear environments in the centers of local (U)LIRGs. These regions, called Compact Obscured Nuclei (CONs), can be as compact as ~20pc, with column densities that can reach values greater than 10^(25) cm^(-2), and have temperatures of >1000K. The most likely nature of the object in the center of these CONs is a dust-enshrouded highly-accreting AGN, and/or an optically thick and compact (<100pc) starburst region. CONs likely represent an important phase of intense growth in the nucleus of galaxies, and fully understanding the mechanisms taking place in their midsts could prove an important step in improving our theories of galaxy evolution. (Sub-)mm H2O maser emission is ideal to probe through the obscuring material to the inner regions of CONs. Here we propose for Band-5 and 7 observations of the 183GHz, 321GHz and 325GHz H2O maser lines, at high spatial resolution that will resolve the emission from the CON. | Galactic centres/nuclei, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2024-07-18T03:21:56.000 |
| 2361 | 2016.1.00005.S | 41 | The evolutionary conundrum of the superwind phase of oxygen-rich asymptotic giant branch stars | Our understanding of the late stages of evolution of 5-8 solar-mass stars on the asymptotic giant branch has been challenged. For over 30 years, the hypothesis was that a high mass-loss-rate superwind of several 10^-4 solar masses per year lasts for ten thousands of years and allows these OH/IR stars to evolve into white dwarfs. However, recent modeling of single-dish (sub)mm and continuum far-IR observations predicts much shorter durations for the superwind phenomenon. This implies that these stars need to lose several solar masses by means other than one superwind. Alternatively, another mechanism could be destroying the diagnostics commonly used to study the superwind at closer distances to the star than expected, e.g. enhanced photodissociation of CO by the interstellar UV radiation field. We propose a study on the superwind of the OH/IR star OH30.1-0.7. By measuring the spatial distribution of CO and dust emission we constrain the mass-loss history and CO photodissociation radius. Using ALMA's unprecedented sensitivity and spatial resolution we can conclusively distinguish which of these two processes is the main cause of the (appearance of the) small-sized superwind. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-06-06T04:12:52.000 |
| 2362 | 2021.1.00485.S | 19 | Enabling a full multiwavength analysis of secondary gas release in debris disks | Beta Pic is the archetypal second generation gas disk. Collisions between planetesimals release molecular gas that sustains a bright, secondary disk in the nearby system. Previous ALMA imaging has identified a bright clump of gas to the SW of the disk that catches the process in the act. Long wavelength observations are required to observe CO(1-0) in the disk to break degeneracy that currently prevents a full physical characterisation of the secondary gas producing environment. Our analysis of molecular excitation in the released gas will be completed utilising archival ALMA observations. Long wavelength (3mm) continuum observations will detect pebbles in the disk tracing closer to the location of larger planetestimals and enable a spatially resolved charaterisation of the dust population. In the future our methods can be extended to other debris disks to distinguish between primordial and secondary origin in the observed gas. | Debris disks | Disks and planet formation | 2023-03-09T11:56:32.000 |
| 2363 | 2016.1.01135.S | 109 | Black Hole Masses, central parsec gas dynamics, and Event Horizon Detectability in a sample of nearby galaxies | Despite it now being well established that nearly all galaxies have a central black hole whose mass scales with the host galaxy properties, we do not have a complete understanding of the physics at work. In particular, we do not know whether black holes, or galaxies, are the driving the scaling relations. Although we know that the M-sigma and M-L relations are incompatible in the largest galaxies, we do not know which is wrong. We are now at the limits of what can be learned with ~80 data points with substantial measurement uncertainties, and urgently require additional precision data. ALMA is capable of measuring black hole masses at high precision for a large number of sources. Here, we propose observations of a modest pilot sample of nearby galaxies in order to: (1) Measure black hole masses in 3 new sources with large angular spheres of influence, (2) measure the central parsec gas dynamics in most or all 8 sources allowing us to better understand the systematics in molecular line black hole mass measurements, and (3) determine suitability for all sources for event horizon shadow resolution with the Event Horizon Telescope. | Galactic centres/nuclei | Active galaxies | 2018-07-24T15:13:10.000 |
| 2364 | 2021.1.01089.S | 800 | The physics behind the bending of the star-forming main sequence at z~0 | It is now well established that star-forming galaxies follow a well-defined relation in the star formation rate (SFR) vs. stellar mass plane, referred to as star-forming main sequence (SFMS). Recent studies have shown that, while this relation is linear from dwarfs to Milky Way-size galaxies, at higher stellar masses it bends towards lower SFRs. The origin of this bending is still debated, and proposed scenarios range from environmental effects to morphological quenching. Surprisingly, most previous work has focused on the optical properties of galaxies on the bending and little is known about their gas content and star formation efficiencies (SFEs). This proposal aims at filling this gap by observing the CO(1-0) line for a representative sample of massive star-forming galaxies at z~0. This sample has been carefully selected to map both the bending and a linear extrapolation of the SFMS at high stellar masses. Our goal is to determine whether SFE remains constant on the locus of the bent SFMS, or if variation in SFE are driving the bending. These observations should provide some clarity on the origin of the shape of the SFMS at z~0 and inform similar studies at higher redshifts. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2023-04-20T19:06:37.000 |
| 2365 | 2015.1.00169.S | 2 | B335: A Test-Bed for Spherical Collapse | We propose to observe the classic isolated protostar B335 in four lines in Band 7. Our sucessful Cycle 1 observations of this source have revealed definitive kinematic evidence for infall in the form of redshifted absorption against the continuum source. Approximately spherical infall appears to extend inward to about 16 AU. Here we propose observations with higher resolution to study the formation of a pseudodisk or rotationally supported disk. | Low-mass star formation | ISM and star formation | 2020-06-29T01:55:03.000 |
| 2366 | 2017.1.01423.S | 31 | The Formation of Massive Galaxies in the Reionization Era | We request spectral imaging of a unique system of massive galaxies in the epoch of reionization (EoR). SPT0311-58 was selected via its millimeter-wavelength dust emission in the 2500-square-degree South Pole Telescope (SPT) survey and is spectroscopically confirmed to lie at z=6.900. The most massive galaxy in this system has the highest dust, gas, and dynamical masses of any galaxy known at z>6. Observations in cycle 4 have provided a gravitational lensing model for this source, demonstrated the existence of multiple interacting galaxy components, and yielded high signal-to-noise detections of the CII and OIII lines. Having begun to characterize the properties of this system, we propose to continue our study by obtaining 1) key diagnostic line images that will help interpret the significant variations in line ratios, 2) higher resolution CII imaging to further explore the dynamics and stability of the ISM in these galaxies, and 3) spatially-resolved measurements of an outflow tracer to study the deposition of metals in the intergalactic medium during the EoR. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-12-18T17:07:44.000 |
| 2367 | 2017.1.01318.S | 118 | Resolving molecular gas in ultra-compact starburst galaxies with extreme outflows | We propose to observe four ultra-compact (r_e~100pc) late stage merger starburst galaxies at z~0.5 that exhibit high velocity (~1000km/s) outflows and no evidence for AGN. These galaxies are among the best examples showing that Eddington-limited star formation feedback can be competitive with AGN for shaping the star formation histories of massive spheroids. We recently obtained CO(2-1) detections of these four targets in ALMA Cycle 4, allowing us to show that the integrated star formation efficiencies (SFE) are already close to the upper limit predicted for radiation pressure feedback. Surprisingly, however, most of the systems show spatially resolved offsets in the CO emission, suggesting that a large fraction of the gas is *not* associated with the central starburst but with molecular outflows or remnant disks. Here we aim to re-observe the same targets at 0.25" resolution to resolve these molecular structures ~1.5kpc scales, placing constraints on the (potentially extreme) SFE in the central nuclear starburst, and exploring the role of molecular gas in driving, and being driven by, central star formation. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2019-04-24T14:08:54.000 |
| 2368 | 2021.1.00452.S | 22 | First Detection of a Prebiotic Molecule in a Protoplanetary Disk | Complex organic molecules (COMs) are seen throughout the solar system and the ISM. However, the number of COMs detected in protoplanetary disks, the sites of planet formation, remains small. This is because the typical protoplanetary disk is too cold for most COMs to exist in the gas phase. Yet chemical models predict dust grains in disks to be active sites of COM ice chemistry. Heating events, such as those in FUor objects, can increase the disk temperature, sublimating COMs. Recently, ALMA detected five COMs in the disk of the FUor object V883 Ori. Here, we propose to use ALMA in spectral scanning mode to detect glycolaldehyde (CH2OHCHO) in V883 Ori. Glycolaldehyde is a prebiotic molecule, a precursor to sugars and, under Earth-like conditions, RNA. Glycolaldehyde was easilty detected as part of the PILS survey of the IRAS 16293 protostellar envelope and should be similarly bright in the V883 Ori disk. This program will achieve the first detection of a prebiotic molecule in a protoplanetary disk, providing observational constraints on complex chemsitry in planet forming disks. | Astrochemistry | ISM and star formation | 2023-12-27T22:08:07.000 |
| 2369 | 2022.1.00300.S | 0 | Resolving the puzzle of growing the ultraluminous quasar at z=6.3 with ALMA and JWST | About 200 quasars have been now discovered at z>6. Chief among them is J0100+2802, an ultraluminous quasar with a twelve billion M_sun supermassive black hole (SMBH), the most massive SMBH known at z>6. Recent ALMA observation resolves the dust emission in J0100+2802 into several clumps, suggesting that it either has multiple star-forming regions or is gravitationally lensed. However, the lensing hypothesis is strongly disfavored by its large proximity zone and a number of spectral properties consistent with high intrinsic luminosity. Kinematic modeling of [CII] indicates that J0100+2802 is hosted by a galaxy with a mass of ~10^11 M_sun, which is fifteen times smaller than expected from the local M_BH-M_dyn relation. These observations have raised many puzzles on this object. We propose high resolution (~0.04'') ALMA observation of [CII] to resolve the sphere of influence of the SMBH and enable a direct measurement of SMBH mass by modeling gas dynamics. Together with the already approved JWST observations, we will measure the spatially resolved star formation, dust opacity and baryon distributions as well as investigate SMBH contributions to dust heating in the quasar host galaxy. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-12-15T07:38:33.000 |
| 2370 | 2012.1.00566.S | 0 | Dense Molecular Gas in the Super Star Cluster Environment of NGC 5253 | Nearby starbursts are forming super star clusters (SSCs), which in many respects appear to be newborn globular clusters. The super star clusters are expected to profoundly influence gas in their immediate neighborhood. Under such hostile conditions, one cannot expect star formation (SF) to proceed in the same fashion as it does in the Galaxy today. It is vital to characterize how SF does occur since every galaxy --- including our own --- goes through an epoch of globular cluster formation. The goal of this project is to use ALMA's great increase in sensitivity (and southern location) to investigate the properties of the natal dense gas toward the extremely young super star cluster forming dwarf, NGC 5253. We propose to map the dense gas tracers, HCN(1--0), HCO$^{+}$(1--0), C$_{2}$H and SiO) on 60 pc scales. The maps will be used to characterize the location, amount, density and chemical properties of the dense gas that form and are influenced by these massive clusters. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2015-06-24T16:02:48.000 |
| 2371 | 2021.1.00705.S | 4140 | Needle in a haystack: Identifying the highest-redshift candidate DSFGs using 2mm imaging | Dusty Star-Forming Galaxies dominate cosmic star-formation at its peak (z~2) and yet little is known of their volume density toward higher redshifts, where their existence may place interesting constraints on the formation of massive galaxies (M*>10^11Msun). Empirical modeling suggests that 2mm imaging of existing, bright samples of DSFGs selected at 850um-1mm can quickly and easily separate DSFGs by redshift, isolating the `needle in the haystack' DSFGs that sit at z>4 or beyond. We propose 2mm dust continuum observations of a sample of 414/453 of the brightest SCUBA-2 850um-selected DSFGs (S850>5mJy) (the other 39 targets were observed in Cycle 7) with the goal of: (1) identifying the highest redshift candidate DSFGs for future follow-up with ALMA spectral scans and JWST, (2) inferring the volume density of z>3 DSFGs using the population's distribution in 2mm flux density combined with our models of (sub)mm emission from obscured galaxies, and (3) refining measurements of beta, the dust emissivity spectral index for a wide range of DSFGs to improve our understanding of galaxies' dust SEDs. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2023-10-03T19:46:16.000 |
| 2372 | 2022.1.01132.S | 40 | A tale of two disk populations in Corona Australis | ALMA disk demographic studies have revealed insightful evolution of disk mass to guide planet formation models. However, most established trends are anchored by the old Upper Sco disks (5-10 Myr), and disentangling the effects of age, environment, and initial conditions remains challenging. A recent Gaia study on Corona Australis (CrA) has revealed two disk populations at distinct evolutionary stages: one clustered at the dense cloud center of 2 Myr vs. one dispersed sample of 12-15 Myr, making it an excellent laboratory to study disk evolution with mininal environmental effects. We propose an unbiased 0.9mm continuum emission survey for 111 disks in CrA (complete down to M6) with a dust mass sensitivity of 0.1 Earth mass. This observational setup ensures a fairer comparison with studies conducted in other regions, especially Upper Sco. With the proposed observations, we will: 1) study the dust mass evolution within the two populations in CrA, 2) resolve the puzzle of very low dust masses known for a subset of CrA disks, and 3) explore disk evolution towards the end of protoplanetary disk phase. This project will make CrA another benchmark region for disk evolution studies. | Disks around low-mass stars | Disks and planet formation | 2024-05-31T22:53:55.000 |
| 2373 | 2023.A.00037.S | 16 | The ISM at Cosmic Dawn: [OIII] in an Uniquely Luminous z=14.3 Galaxy | JADES-GS-z14-0 was recently spectroscopically confirmed to be the most distant galaxy in the universe at z=14.3 and also has the distinction of being the most luminous spectroscopically confirmed galaxy at z>8 visible to ALMA (GNz11 is too far north). Also relatively unique amongst z>10 galaxies, the majority of its luminosity is extended and from stellar origins, indicating a rapid build-up of stellar mass at early times. Here we propose deep observations of JADES-GS-z14-0 with two tunings in band 6 targeting the [OIII]88um line, covering 98% of the redshift probability distribution to a factor 2x below the [OIII]-SFR relation. This will allow a precise measurement of the spectroscopic redshift and insight into the ISM properties of a galaxy at the earliest epochs of cosmic history. Our observations also enable deep constraints on the dust continuum emission of JADES-GS-z14-0 to test for early dust build-up already at z~14. Given the exciting, pathfinding nature of this source, there is urgency to obtain these observations already in Cycle 10 such that the results are available for next ALMA/JWST cycles, and ALMA will shortly be in the ideal configuration to observe this source | Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-09-30T07:12:07.000 |
| 2374 | 2018.1.01766.T | 176 | Observing Jets and Outflows in Tidal Disruption Events with ALMA | Transient accretion onto a supermassive black hole (SMBH) through the tidal disruption of a stray star offers a unique opportunity to study the birth and evolution of relativistic jets and to probe the environment around previously dormant SMBHs on sub-parsec scales. Tidal disruption events (TDEs) have long been predicted to produce optical/UV/soft X-ray transient emission from the newly-formed accretion disk, but in the past few years we have shown that some TDEs can also launch relativistic jets and broad outflows, which generate synchrotron emission that peaks in the mm on timescales of days to weeks. To address the open question of jet and outflow formation requires: (i) a larger sample of TDEs from a diverse range of selection methods, and (ii) deep mm follow-up, only possible with ALMA. Here, we propose to observe up to 4 new TDE candidates with triggers from gamma-ray, X-ray, or optical surveys (Swift, Fermi, XMM-Newton Slew Survey, Pan-STARRS, CRTS, DES, ASAS-SN, ZTF). Our mm observations will be sensitive to both non-relativistic outflows and relativistic jets and will constrain jet formation models and rate predictions, which are currently highly uncertain. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2020-01-02T16:10:00.000 |
| 2375 | 2011.0.00015.SV | 0 | Science verification observation of HL Tau | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Disks around low-mass stars, Astrochemistry | Disks and planet formation | 2016-06-24T14:02:07.000 |
| 2376 | 2015.1.00283.S | 32 | Serpens South: Morphology and kinematics of the protostar at the cluster center | A model for low-mass star formation is generally understood to incorporate a bipolar jet/outflow, envelope, and disk. Until now, the precise mechanisms of momentum transfer, jet launching, infall and envelope rotation -- relating all of these complementary protostellar components -- remained observationally elusive, yet ALMA is now able to probe the full range of spatial scales from outflow to disk. In Cycle 3, we propose Band 7 observations of the envelope and disk kinematics of the young protostellar source in the Serpens South cluster. These observations with spatial resolution of 60 AU, which also allow a study of the jet structure near the source, will complement our ALMA Cycle 1 observations of the collimated and episodic outflow. Together, we suggest that ALMA can provide a comprehensive case study of the inter-related jet/outflow and rotation/infall mechanisms during the class 0 stage of star formation. | Intermediate-mass star formation | ISM and star formation | 2018-06-15T11:07:37.000 |
| 2377 | 2015.1.00783.S | 15 | Probing cool dust across the white dwarf cooling track: evidence for planetary remnants in evolved systems | Over the past few years it has become increasingly clear that evolved planetary systems around white dwarfs are as frequent, and varied, as those around main sequence stars. Compact debris discs, formed by the tidal disruption of planetesimals, are found around many single white dwarfs, and transit timing variations reveal the presence of circumbinary planets around eclipsing white dwarf binaries. We detect large amounts of cool dust around one of these binaries, NN Ser, in our ALMA Cycle 2 data. Here, we propose an efficiently designed ALMA survey for cool dust around one dozen single and binary white dwarfs spanning cooling ages from ~50 Myr to ~1 Gyr. The evolution of the dust mass as a function of age will provide the first direct insight into the dynamical post main-sequence evolution of planets and planetesimals, and we will use the results to test and further develop our models for evolved planetary systems. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2017-11-15T16:21:26.000 |
| 2378 | 2011.0.00083.S | 0 | The footprints of SF and AGN activity in NGC1068: a case study for ALMA | We propose to map the emission of a set of dense molecular tracers (the 3-2 and 6-5 lines of CO, and the 4-3 lines of HCN and HCO+) in the central ~1.5kpc of NGC1068 using the unique spatial resolution (0.25"-0.50") and sensitivity capabilities of the extended configuration of ALMA in bands 7 and 9. NGC1068 is a prototypical Seyfert 2 galaxy with an inner circumnuclear molecular disk (CND) and a starburst (SB) ring at larger radii. These maps will spatially resolve the gas flows in the CND and the SB ring with unprecedented sensitivity. This will be a key ingredient for the dynamical models developed by our team that study AGN feeding mechanisms. Furthermore, combined with the available interferometer images obtained in the low-J transitions of these molecular species by our group, the ALMA maps will be used to study the spatial variations of the SEDs of CO, HCN and HCO+. A set of diagnostic line ratio maps will be interpreted in the light of new chemical models, developed inside the team, which address the feedback of star formation and AGN activity on molecular gas. Besides yielding a high scientific output, these observations will test key ALMA performances during cycle 0. These include the ability to build moderately large mosaics of >10 fields, and testing the reliability of observations done in band 9 with the extended configuration of the array. | Active Galactic Nuclei (AGN)/Quasars (QSO), Spiral galaxies | Active galaxies | 2013-10-08T11:41:00.000 |
| 2379 | 2019.1.00838.S | 53 | The first complete redshift distribution of 3mm-selected sources | We have analyzed, for the first time, the potential of 3mm observations to detect high-z DSFGs. This wavelength naturally filters out z<2 galaxies due to a very negative K-correction. We find 16 serendipitously-detected 3mm sources within ~200 sq. arcmin of ALMA archival observations. We aim to derive the first 100\% complete redshift distribution for the largest sample of $3\,$mm-selected galaxies, following the success of our Cycle 6 observations. We request observations for only the 7 sources that lack robust spectroscopic redshifts (out of 16). Two of them have already single-line detections and require only one tuning in Band 3, while for the remaining three targets (which were not observed or partially observed during the last cycle) observations to complete the Band 3 + Band 4 spectral scan is requested. This work will reveal the nature of 3mm galaxies, their first complete redshift distribution, and their contribution to the cosmic star formation rate density. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-04-03T14:54:06.000 |
| 2380 | 2019.1.00853.S | 15 | High redshift star formation at ~500 pc: investigating gas and star formation laws in a main sequence galaxy at z~2 | For the first time we will resolve dense star forming gas in an unlensed main sequence galaxy at z>2 at ~500pc. BX610 is a main sequence galaxy which, unlike many galaxies studied at high redshift, is undergoing modest star formation spread throughout the disk, with long gas depletion timescales. It therefore represents an under-studied, but important population in the early universe. We have carried out low resolution observations of CO lines and [CI] to determine bulk molecular and atomic gas properties and we recently used ALMA's exquisite capabilities to observe CO(4-3) and [CI](1-0) at 500pc resolution. We propose observing CO(7-6), [CI](2-1), and H2O at matching resolution, as well as continuum near the peak of the infrared dust SED. These observations will reveal warm star forming gas and directly probe the obscured star formation. This will enable unprecedented analysis of the conditions of star forming gas. Paired with our previous high-res data we will measure resolved gas depletion times, test the Kennicutt-Schmidt law in a new environment, characterize gas conditions through resolved LVG and PDR models, and investigate additional heating mechanisms such as shocks. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2022-06-11T17:00:42.000 |
| 2381 | 2021.1.00315.S | 31 | A first study of inner rotation curves in cluster galaxies at z=1.5 | Inner rotation curves of galaxies are sensitive to the gravitational potential of a bulge in the central 1 kpc regions of galaxies. We here propose to make 0.15 arcsec(1 kpc)-resolution observations of CO(5-4) emission line in 16 cluster galaxies at z=1.46, in which the CO(2-1) line emission is detected. We will spatially resolve the CO(5-4) emission and explore the gas kinematics of high density gas in cluster galaxies. The combination of the 0.15 arcsec-resolution CO(5-4) and previous 0.5arcsec-resolution CO(2-1) observations will allow us, for the first time, to probe the radial distributions of baryonic mass (gas and stars) over a wide range from the central 1 kpc regions to the outer disks and to accurately determine the bulge-to-disk mass ratio in high-redshift cluster galaxies, which are expected to grow into massive elliptical galaxies in the present-day Universe. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2023-12-27T20:13:46.000 |
| 2382 | 2012.1.00539.S | 2 | Molecular gas and starforming regions in disky U/LIRGs - analogs for high-z starforming galaxies | We propose CO(1-0) observations of 6 z ~ 0.1 infrared-luminous galaxies that are distinguished by large diameter and disky, non-merger structure, at IR luminosities 10^11.5 − 10^12.0 L_sun. They are selected from IRAS+SDSS to be very IR-luminous yet also disky. These 6 are ALMA-accessible galaxies from a sample of 16 for which we are measuring far-IR fine-structure lines of [C II], [O I], [O III], and [N II] with Herschel, to constrain physical conditions (density, ionization) in their star forming regions. These galaxies are interesting because they have high star formation rate activity spread over a large physical area, rather than concentrated into extremely dense regions as in the nucleus of a major merger, as in most low-z ULIRGs. They appear to be good analogs for high-redshift IR-luminous galaxies. Unlike low-z U/LIRGs, many z >= 1 LIRGs and some ULIRGs appear to be disky, although with much higher gas fractions than local disks. High-z galaxies show far-IR spectral shapes different from local ULIRGs and in a few cases where [C II] can be measured, high L([C II])/L(FIR). CO observations of these low-z analogs will measure the gas mass fraction, the spatial extent and surface density of molecular gas, and the star formation efficiency L(IR)/L(CO). These are critical to test the Kennicutt-Schmidt star formation relation, to place these galaxies in context of local galaxies, and to understand high-redshift, spatially unresolved galaxies. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2015-07-09T20:53:18.000 |
| 2383 | 2018.1.01885.S | 46 | Filament formation by low-velocity shocks in the Musca cloud | To understand the earliest stages of star formation, one has to understand how dense prestellar cores can form out of the low-density turbulent interstellar medium. The Herschel Space Telescope has established that in this process, first dense filaments form which can then fragment into prestellar cores. A promising formation scenario for these dense filaments is dynamic mass accretion by dissipating turbulence through low-velocity shocks. To confirm this scenario, direct evidence of such shocks and their link with dense gas formation is essential. With recent APEX observations we were able to establish a warm gas phase, typical for such shocks, that shows indications of mass accretion on the Musca filament at locations where such low-velocity shocks would be expected. To confirm this dynamic accretion scenario we propose to characterise the physical conditions of this warm gas, study it with dedicated shock models, and further establish the link with dense filament formation. To do this, the sensitivity and resolution of ALMA is required. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-11-12T12:35:10.000 |
| 2384 | 2023.1.01456.S | 0 | A pilot survey of CO in blindly detected HI-rich dwarf galaxies in the Virgo cluster | We propose to observe with the ACA five dwarf galaxies that were detected in HI in the pilot field of the MeerKAT Survey of the Virgo Cluster and have not previously been observed in CO. These observations will serve as a pilot for a larger future proposal to follow up more HI detections once the MeerKAT survey is complete. The ongoing MeerKAT survey is blindly mapping HI in the entire Virgo cluster, thus resulting in an unbiased, complete HI survey of Virgo for the first time. The MeerKAT fields thus far observed have revealed substantial and spectacular HI reservoirs in several dwarf galaxies, a population thus far largely overlooked (existing surveys of Virgo almost exclusively target massive spirals). If we aim to understand the effects of environmental quenching on the baryon cycle, the follow-up of these detections in CO is essential. The stellar masses of the proposed sample are distributed around 10^9 Msol, a sweet spot between substantially lower Mstar compared to existing CO observations and high enough metallicity to detect CO in relatively short amounts of time, which is curently only possible with the ACA. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2025-08-06T19:39:43.000 |
| 2385 | 2018.1.00421.S | 3 | A Comprehensive View of Magnetic Fields around Young Protostars NGC1333 IRAS 4A1 and 4A2 (II) | This is a continuation of our A-ranked Cycle 3 program on IRAS4A, where only one of the two science goals (Band 7 polarization) was observed. Here we propose to finish the other science goal and leverage the Band 7 polarization data to disentangle contributions to polarization from dust scattering and magnetically aligned grains with additional Band 4 observations. Measuring polarized emission from aligned dust grains have been the most efficient method to probe the structure of the magnetic fields in star-forming regions. However, recent theoretical and simulation work by Katoaka et al.\ (2015) and Yang et al. (2016a,b) demonstrated that the polarization originated from scattering cannot be ignored in the protostellar disks. Surprsingly, dust grains grow big enough to produce significant scattering at ALMA Band 7. To distangle the contribution of polarization from scattering and dust emission, we request dust polarization observations at Band 4. In addition, we request to complete the unfinished science goal of our Cycle 3 program for the polarization power spectrum analysis to measure the relative importance of magnetic fields and turbulence. | Low-mass star formation | ISM and star formation | 2020-11-01T00:00:00.000 |
| 2386 | 2023.1.01730.T | 0 | Relativistic Explosions in Dense Circumburst Matter | In the last few years, optical surveys established a new class of transients whose prototype is AT2018cow. Such events are interesting laboratories for shock-acceleration and compact-object activity: whereas in other transient laboratories (gamma-ray bursts and supernovae) the compact object remains shrouded by the ejecta, in AT2018cow it is exposed. Furthermore, the evolution of the radio spectral energy distribution (particularly at mm wavelengths) is difficult to reconcile with the standard shock-acceleration prescription used to model GRBs and SNe. Here we request detailed multi-band VLA+ALMA observations for a single event in 24B (follow up extending to 25A). With ZTF we can routinely discover one AT2018cow-like event per year, and the false positive rate for our triggering criteria is low. By tracking the evolution of the radio SED from high to low frequencies, we seek to (1) determine whether an unusual electron population may be present, (2) measure the density profile of the ambient medium, and (3) characterize the central engine by measuring the properties (energy, duration) of its outflow, which recent results suggest may be a relativistic jet. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2025-11-06T18:08:17.000 |
| 2387 | 2023.1.00131.S | 0 | The first ALMA survey of protoplanetary disks in Band-10 | Spatially resolved multi-frequency observations of protoplanetary disks provide a robust way to constrain disk properties for large samples. This approach can be used to derive temperature, surface densities, and grain size distributions as a function of radius directly from the data. However, it requires observations sampling a wide range of optical depths, from very optically thick to very optically thin emission. While data at low (Band-3 or 4) and intermediate (Band-6 or 7) frequencies sampling low and intermediate optical depths are already available in the archive for large samples of disks, high-frequency ( Band-9 or 10) data is still unavailable. Here we request Band-10 observations at 0.1"-0.2" resolution of the 45 brightest and largest disks in the Ophiuchus molecular cloud. The Band-10 observations will be combined with existing data in Bands 3, 6, and 7 in order to constrain their temperature, surface density, and maximum grain size as a function of radius. The results of the program will serve as a benchmark of disk properties to guide a wide range of planet formation and disk evolution studies. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 2388 | 2022.1.00884.S | 123 | Redshift scans for dusty star-forming galaxies at cosmic dawn | Dusty star-forming galaxies have been found in the reionization epoch, but only few are spectroscopically confirmed at z>6 and the role they played at such an early time is largely unknown. By cross-matching ALMA archival data to the deepest multi-wavelength catalogs in the COSMOS field, we selected four candidates at z>6 with the reddest FIR SEDs in COSMOS. They all drop out from the deepest optical/HST images, two of them are even not seen in IRAC and Herschel, but all are well detected in ALMA, SCUBA2 and radio. These extreme properties suggest that they might be among the most distant dusty galaxies, making the redshift confirmation the most urgent step to push our understanding of their nature. We propose ALMA 3mm line scans to confirm their redshifts, measure their gas and dust properties and constrain dusty star-formation activities at the earliest cosmic time. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-02-03T12:34:24.000 |
| 2389 | 2017.1.00201.S | 21 | Unraveling the connection between carbon and CO in two gaseous debris disks | Debris disks are products of the planet formation process and can thus help us to understand the origin and evolution of planetary systems. Debris disks are generally gas-poor, but a few contain observable amounts of CO that might be leftover primordial gas or of secondary origin (e.g. produced from comets). Studying the gas can help us understand the evolutionary state of these peculiar disks and constrain the composition of the gas-producing bodies. Some systems also contain atomic gas that can be produced from photo-dissociation of CO. Recent hydrodynamical models predict that the atomic gas produced this way should form an accretion disk inwards of the CO. We propose to study the relation between CO and atomic carbon by obtaining CI maps for two targets for which both ALMA CO maps and Herschel CII detections are available: 49 Ceti and HD 32297. By comparing to the CO maps, the data will directly reveal the origin of the atomic gas, and will enable us to test the predictions from hydrodynamical models. Combining the CI maps with the CII detections will determine the ionisation state, electron density and total carbon mass of the disks. | Debris disks | Disks and planet formation | 2019-06-15T09:31:57.000 |
| 2390 | 2017.1.01478.S | 0 | Properties of a photoevaporating disk in Orion | When protoplanetary disks are irradiated by energetic photons, their surface can be heated to high temperatures allowing the gas to escape from the gravitational field. This process is called photoevaporation (PE). Proplyds are a class of disks where PE is dominated by far-UV photons originating from nearby massive stars (external photoevaporation). During ALMA cycle 1 observations of the Orion Bar, members of this team serendipitously detected intense HCO+(4-3) emission towards the proplyd "203-506". This emission was unresolved with the 1" beam. Preliminary analysis shows that it is likely that this emission originates from a PE flow, making of HCO+ a potentially good probe of PE. Our goal is to spatially resolve the HCO+ emission from the disk and flow, as well as the emission from HCN and CS from the disk, using a spatial resolution of 0.1" in band 7. Combined to a dedicated 3D radiative transfer model, we will be able to determine directly the density and velocity of the flow, i.e. the key parameters determining the mass-loss rate, the mass of the central star and of the disk. This will provide key constraints on the physics of external PE and on the lifetime of proplyds. | Disks around low-mass stars | Disks and planet formation | 2019-01-03T20:13:12.000 |
| 2391 | 2015.1.00279.S | 26 | Triplets of Quasars: Exploring the Origin of Clusters with ALMA | In the current hierarchical paradigm for the assembly of cosmic structures, rare systems such as triplets of physically associated QSOs at z~2 are thought to be the signature of extremely rich environments, where frequent galaxy interactions and an intense star formation activity are expected. A fundamental parameter for the aforementioned processes is the amount of molecular gas available to fuel the star formation and the nuclear activity of these systems. We here propose to utilize the unprecedented sensitivity of ALMA to study the only two QSO triplets known so far, probing the CO emission of six QSOs with only two pointings. These data will allow us to test our understanding of galaxy formation theories, study the complex interplay between the molecular gas reservoir and the QSO activity, and the formation of the first massive cosmic structures. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-12-08T18:46:42.000 |
| 2392 | 2023.1.00717.S | 0 | ACA Band 10 survey of HCN lasers in carbon-rich stars | We propose to carry out a standalone 7-m array survey to search for hydrogen cyanide (HCN) laser line emission near 805, 891, and 894 GHz in carbon-rich evolved stars. The 805 and 891 lines show intense emission in archival ALMA Band 10 data. HCN is one of the most abundant molecules in the envelopes of carbon stars and is produced efficiently at radii very close to the photosphere. The two far-infrared lasers have excitation energies above 4200 K and, if present, would exhibit very intense and relatively compact emission. The main goal of this survey is to efficiently identify more HCN laser sources and to study the conditions of laser emissions. Furthermore, the data products will contain broadband line and continuum data for the observed carbon stars, allowing the studies of HCN excitation, dust formation, and stellar continuum emission. The flux density and source size constraints will allow us to plan for future high-frequency, longest-baseline observations aimed at understanding the physics of convection and pulsations in the photosphere of evolved stars with an angular resolution of 5-10 mas. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2025-09-10T08:12:27.000 |
| 2393 | 2017.1.01102.S | 11 | The Initial Conditions of Planet Formation in the Youngest Rich Cluster | Most stars, including our Sun, form in clustered, high-mass star forming regions. We propose to study protoplanetary disks in the youngest rich cluster to date, the 0.5-Myr-old NGC 2024 cluster in Orion. We will observe 186 young disks with ALMA, in order to constrain the initial conditions of the planet formation process. NGC 2024 is a compelling region for multiple reasons, its extreme youth, the suggested ubiquity of disks in the region, and its resemblance to our Sun's birth environment. The proposed ALMA disk study will be highly complementary to infrared studies of young stars in NGC 2024 with the VLT and JWST, both led by members of our team. VLT spectra are already in hand, while imaging observations with the JWST are forthcoming. These multi-wavelength observations will allow us to do a comprehensive study of stellar and protoplanetary disk properties in the youngest rich cluster to date and constrain the potential to form planets in an environment most typical of star formation in our Galaxy. With such observations, NGC 2024 will be a benchmark region for all future star and disk evolution studies. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2019-02-27T21:01:16.000 |
| 2394 | 2016.1.01206.S | 29 | Understanding the chemistry of Venus mesosphere: mapping H2O, HDO | We propose to observe simultaneously H2O and HDO in the upper atmosphere of Venus using ACA only measurements with the main goal to map the D/H ratio with unprecedented precision both on the dayside and the nightside of Venus. Venus is significantly drier than the Earth, and the large enrichment of deuterium to hydrogen (about 200 the terrestrial value) suggests that a dramatic escape of water from Venus occurred. Mapping the abundance of water in Venus mesosphere can help understanding both the evolution of the Venus atmosphere and its current structure and chemistry. We will also retrieve the temperature and CO vertical distributions and mesospheric winds in the vicinity of the morning terminator (June 2017), allowing us to couple photochemical and dynamical processes. As a by product of these observations, maps of SO will be also acquired. Sulfur species, together with water vapor, play an important role in the photochemistry of Venus upper atmosphere. | Solar system - Planetary atmospheres | Solar system | 2018-12-19T12:15:04.000 |
| 2395 | 2021.1.00728.S | 5 | Beads-on-a-string: The formation and evolution of GMCs in NGC4321 | The accumulation of the interstellar medium into giant molecular clouds (GMCs) represents the first stage of the star formation process. The properties of GMCs control the rate and efficiency with which stars form in galaxies. Understanding how these properties depend on the mechanisms by which GMCs form is essential for progress in star formation research. We propose to observe a chain of regularly spaced giant molecular clouds along a 5.5 kpc long portion of a spiral arm in the nearby galaxy NGC4321. Because of their regular spacing, these GMCs are suspected to have formed via gravitational instabilities and their surrounding velocity field is consistent with gravitational inflow. As such, they offer a unique opportunity to study molecular cloud formation in action. We propose to map this region at a spatial resolution of 0.2 in ALMA Band 6. This investigation will: i) Distinguish between different GMC formation mechanisms by comparing the properties of GMCs to those predicted by theory; ii) Quantify the extent to which the properties of GMCs, and hence their star formation potential, are inherited from the large-scale convergent flows that drive their assembly. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-12-27T20:52:21.000 |
| 2396 | 2019.1.01257.S | 1920 | A redshift survey of Herschel ultrared dusty, star-forming galaxies at z > 4 | Studies of rare z > 4 dusty, star-forming galaxies (DSFGs) are important for understanding the physical drivers of extreme star formation, mass assembly and growth, and their evolutionary connections with other populations. The largest Herschel surveys, HerMES and H-ATLAS, have selected a large number of DSFGs. Selecting those with ultrared colors in SPIRE bands ('500um-risers': S500 > S350 > S250) is extremely efficient for identifying DSFGs at z > 4. We are carrying out a multi-wavelength observational campaign aimed at characterizing their gas, dust, and stellar properties. The most urgently missing information are their spectroscopic redshifts. We propose ALMA 3mm spectral scans of 38 Herschel ultrared DSFGs to obtain robust spectroscopic redshifts, via the detection of multiple molecular and/or atomic lines. This will be a complete redshift survey of DSFGs at z > 4 down to the 500um-riser selection thresholds. All the targets in this sample have existing multi-wavelength data including Spitzer/IRAC, and are just awaiting spectroscopic redshifts, in order to to fully characterize this population, and determine the space density, SFR density, and stellar mass density at z > 4. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2021-03-10T19:15:56.000 |
| 2397 | 2018.1.01054.S | 69 | Zooming in onto the smallest dust cavities in Lupus disks: are they similar to the large-scale equivalents? | ALMA has revolutionized our view of transition disks by spectacular images of dust rings and asymmetries for cavity sizes of tens of AUs, hinting at clearing by giant planets or substellar companions. However, transition disks with smaller cavity sizes (<20 AU) have so far remained unexplored. We propose to observe 10 transition disk candidates in Lupus with cavity size estimates between 2 and 16 AU (albeit with large uncertainties) based on their Spectral Energy Distribution. The cavities will be well-resolved at 25 mas resolution with ALMA in Band 6 continuum and 12CO 2-1, allowing an accurate measurement. This sample of well-characterized Lupus disks will allow us to see if there is a continuous distribution of cavity sizes (hinting at a common origin) or a bimodal distribution, where the small cavity sizes could be linked to photoevaporation rather than clearing by companions. This is the first systematic study of small transition disk cavities at the scales of our Solar System. | Disks around low-mass stars | Disks and planet formation | 2020-12-24T17:50:23.000 |
| 2398 | 2022.1.01118.S | 10 | Dissecting the ISM of a normal star-forming disk at z=4.5 down to the 500 pc scale | We propose a deep and very high resolution (500 pc) observation of a main-sequence rotator at z=4.5. While the sub-kpc ISM structure in high-redshift starbursts/SMGs has been explored, normal z>4 systems remain an uncharted territory at this resolution. Because of its high surface brightness, its HST and planned JWST observations (COSMOS-Web), VC875 is by far the best candidate to start this type of observations. These observations will resolve the gas clouds, which are the seeds of star formation, and provide high quality dynamical information. We will: 1) reveal the small-scale ISM properties of VC875, detect giant molecular clouds, and measure their dynamical mass; 2) study the resolved Kennicutt-Schmidt relation; 3) probe the baryon cycle by detecting possible outflows and unveiling the nature of the [CII] halo of VC875; 4) measure from the dynamics the total mass distribution and its connection with the gas and stellar components. In addition, three lower-z (z=1.3,2.0, and 3.4) bright continuum sources are located in the same pointing, allowing for free very high-resolution comparisons of dust versus stellar morphologies, together with the local variations of dust attenuation. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2024-03-24T21:01:24.000 |
| 2399 | 2016.1.00715.S | 71 | Origin of transitional disks with small dust cavities | Transitional disks with dust cavities form the best laboratory for studying disk evolution and planet formation 'in action'. Different explanations for their structure have been put forward, ranging from embedded young planets clearing their surroundings to photoevaporation and dead zones. So far, all ALMA observations have targeted bright disks with high accretion rates and large cavities (>15 AU) that could be resolved in Cycles 0-2 and for which the presence of a massive companion is a likely explanation. The only exception lies with TW Hya, which due to its close distance can be studied in exceptional detail. In contrast, models predict that small hole sizes in fainter disks may be due to photoevaporation. Here we use the enhanced long baseline capabilities of ALMA Cycle 4 to resolve the small cavities (<15 AU) of faint disks (fluxes < 10 mJy at 230 GHz) with low accretion rates for the first time. Observations of both the gas and dust, combined with our state-of-the-art models, will be able to determine the physical processes at work and whether there are indeed (at least) two classes of transitional disks. | Disks around low-mass stars | Disks and planet formation | 2018-08-02T17:24:05.000 |
| 2400 | 2018.1.01358.S | 7 | The Magnetic Heart of NGC253's Starburst-Driven Wind | We propose Band 4 and 7 polarization observations of the central starburst region in the nearby galaxy NGC253. The proposed observations will trace the magnetic field structure at spatial scales between 5 and 200pc, yielding the first parsec-scale map of the magnetic field structure in the dense gas at the heart of a starburst system. The data will provide 10 times better linear resolution than the best existing radio polarisation map for NGC253, and increase the number of measurements of the dust polarisation in NGC253 by more than two orders of magnitude. This will permit a detailed study of the magnetic field geometry relative to wind-driven ISM structures at other wavebands. We will use the data to test MHD models for the survival of cold gas entrained in galactic winds, an important outstanding puzzle for galactic wind physics. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2020-10-10T14:45:57.000 |
| 2401 | 2019.1.00912.S | 43 | A second epoch of Serpens South's most spectacular outflow | We have discovered and reported on a protostar driving a distinctly episodic outflow, which provides an observational signpost of episodic accretion. This source, named CARMA-7, is part of Serpens South that was mapped with ALMA in Cycle 2 at 1 arcsec resolution, and then we targeted this source in Cycle 5 with 0.14 arcsec resolution, equivalent to 60 au. At such high angular resolution, C7 reveals arguably the most complex structure in position-velocity space of any outflow observed at mm-wavelengths, as well as a chemically rich core, suggesting that it is actively accreting. We propose to use its apparent protostellar outflow variability as a proxy for accretion events. In order to better constrain its outflow characteristics, we need to know (1) proper motions and inclination angle; and (2) temperature structure along the jet. With this information, we will compile a mass-loss history for this young source, and investigate the link to accretion history. | Intermediate-mass star formation | ISM and star formation | 2022-08-17T18:46:11.000 |
| 2402 | 2016.1.01124.S | 18 | The dust temperature structure of large rings | A picture is emerging for the shaping of large cavities by planet formation, in which narrow rings and their azimuthal structure can be readily explained with the dust trap phenomenon. However, resolved multi-frequency observations, in the single case where they are available, i.e. in HD142527, reveal unexpected structures. The continuum is double-peaked in azimuth, and the peak optical depths and continua are not coincident because of the temperature structure. In the case of MWC758, the continuum also appears to be double-peaked. Another type of asymmetry is seen in HD34282, with a mild peak in an otherwise perfect ring. Is this mild asymmetry also due to dust trapping? Here we propose to acquire Band9 continuum data, and complementary low-frequency data, to measure the dust temperature structure of the large rings in MWC758 and HD34282, and build continuum optical depth maps. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2018-10-03T14:05:19.000 |
| 2403 | 2019.1.01128.S | 3 | A Magnetized Jet from a Very Massive Protostar | In the formation of very massive stars, intensive radiative feedback becomes so significant that it potentially can halt the mass accretion completely. In order to unveil the formation process of very massive stars, we propose a high-resolution polarization imaging toward a very massive protostar G45 at Band 3. From our previous observations of this source, we found a bipolar photoevaporative outflow associated with a nonthermal spectral features which indicates synchrotron emissions associated with a strong jet from this very massive protostar. With the proposed observation, we aim to detect the linearly polarized synchrotron emission to confirm the existence of such a jet. The presence of such a jet, if proved, is a direct evidence of ongoing accretion overcoming the strong radiative feedback. We will use the linearly polarized synchrotron emission to constrain the magnetic fields in the jet. Moreover, with Faraday analysis, we may also be able to use this linearly polarized emission to constrain the magnetic fields in the ionized photo-evaporative outflow surrounding the jet. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2024-02-11T01:09:55.000 |
| 2404 | 2016.1.00564.S | 507 | Gas mass fractions in z>3 main sequence galaxies from ALESS | The ECDFS is one of the best studied cosmological deep fields. Through a 10 year effort, we have uniquely characterized the 870 micron selected galaxy population in this field across the electro-magnetic spectrum. One of the unique properties of this galaxy sample is its large number of main sequence galaxies at z~2 to 5. As major contributors to the comoving star formation rate density, these sources provide a unique laboratory to study the evolution of the comoving gas mass density and to relate the gas content of galaxies to the evolution of the star formation rate density at redshifts z>2.5. So far no consensus of the comoving gas mass density measured in representative galaxies at these early epochs has been emerged. We here propose to improve on this situation by adding gas mass estimates from CO line and long-wavelength dust continuum emission in ~20 main sequence galaxies in 3 redshift bins between z=2 to 5. Our study aims to cross calibrate CO and dust based gas mass estimates in our 870 micron selected sources with existing surveys at z=2-3 and to add new estimates of the gas mass fraction based on both techniques in two more redshift bins at z=3-4 and z=4-5. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-03-13T15:46:35.000 |
| 2405 | 2015.1.00644.S | 10 | Nuclear outflow and inflow in the strongest X-ray cool core of nearby galaxy groups | The importance of the radio-mode AGN feedback for cosmic structure formation and evolution has been widely recognized. However, many unanswered questions remain. How does the radio AGN work on the cold gas that fuels SF? Is the radio AGN fueled by hot gas or cold gas? ALMA observations provide a powerful means to study radio-mode AGN feedback in BCGs, where a large amount of molecular gas is often detected. This is well demonstrated by some early ALMA programs. Here we propose ALMA observations on a nearby group cool core, A3581 at z=0.0218. It hosts a spectacular optical emission-line nebula and CO emission has been detected by IRAM-30m. Evidence for outflow and inflow has also been found with the multi-wavelength data we have. A3581 offers the best chance to study nuclear outflow and inflow in an X-ray cool core with a strong radio AGN in detail, for its proximity and rich kinematic features near the SMBH. A modest investment of the ALMA time (2.43h) is requested with the C36-3 configuration to achieve an angular resolution of 0.5''. The results will offer clues on some important questions of radio-mode AGN feedback. | Outflows, jets, feedback, Early-type galaxies | Active galaxies | 2017-10-19T16:20:13.000 |
| 2406 | 2021.2.00185.S | 22 | Probing Multiphase CGM in SMM J02399 | Previous observations of Ly, [N II]122, CO strongly suggest the existence of a cold, dense and enriched circum-galactic medium (CGM) composed of neutral, ionized and molecular gas, extending up to 100 kpc scale surrounding SMM J02399, potentially fueling the strong star formation and AGN activity in the central galaxies. However, the mass and physical conditions in the large-scale CGM still remain unconstrained. Here we propose to utilize neutral gas tracer [C II], ionized gas tracer [N II]122, molecular gas tracer [C I]609 and CO(5-4) to map and characterize the multiphase gas in CGM. We aim to (1) confirm the extended nature of [N II]205, CO, and [C II] from CGM; (2) map ionized and neutral gas in CGM; (3) constrain physical properties in CGM; (4) derive the scaling relation between Ly and [C II] to assess the powering/excitation mechanism of the former. A successful detection of [C II] in Ly nebulae will also pave the way for the future CGM [C II] surveys, which will answer the key questions including the physical condition of the cold gas in CGM, the mass exchange between CGM and central galaxies, and the evolutionary effect of CGM in fueling star-formation and AGN. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-09-06T19:44:11.000 |
| 2407 | 2019.2.00125.S | 0 | Dust in the massive AGN outflow of the extremely radio-quiet galaxy NGC1377 | We propose ACA Band 7 and 8 continuum and CO 3-2, [C I] observations of the dusty lenticular NGC1377, which is in a transient evolutionary phase and stands out as being extraordinarily radio quiet. It also has a remarkable combination of an AGN-powered, highly collimated, molecular jet and a wide-angle molecular outflow. There are no signs of ongoing star formation in NGC1377 and our previous high-resolution observations reveal that there is only very faint continuum dust emission in the nuclear region. Evidently much of the dust emission arises on larger angular scales and our goal in this proposal is to search for the missing dust continuum, and to test the notion NGC1377 have its dust luminosity dominated by a massive, powerful AGN outflow. Hence we require the ACA to search for the missing flux and to determine its spatial distribution. We will use CO 3-2 and [C I] emission to map the full extent and dynamics of the outflow and search for evidence that it is an "AGN feeding fountain" - i.e. that gas and dust decelerates in the outflow and returns as inflowing gas to the central region of NGC1377. There it may again become available to fuel another SMBH growth cycle. | Outflows, jets, feedback | Active galaxies | 2022-09-24T16:13:49.000 |
| 2408 | 2018.1.00749.S | 21 | Observing the wind acceleration of Mira in real time | We aim to study the mass-loss process experienced by low- and intermediate-mass stars at the end of their lives using quasi-simultaneous observations of the gas and dust. This proposal follows up on the first simultaneous spatially-resolved observations of this type obtained by us towards Mira Ceti. We used ZIMPOL/VLT images to map the distribution of the dust grains expected to drive the outflow and ALMA observations to study the density, temperature, abundances, and motion of gas in the innermost regions of the circumstellar envelope. We observed an intimate connection between the distribution of the dust grains and the gas. Moreover, we derive important constraints to theoretical models of AGB stars, such as the size of the first dust particles to form. With the proposed observations, we aim to measure the silicon depletion into dust and to monitor the wind-driving mechanism in real time. These new data will provide important additional constraints, such as on the propagation of shocks in the innermost regions of the envelope, on the efficiency of dust growth under well-constrained gas conditions, and on the drift the dust grains experience through the gas. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2021-01-28T12:16:18.000 |
| 2409 | 2018.1.01016.S | 14 | Sodium Shadows - a new tracer of the coldest gas in cluster cores | The cores of clusters of galaxies are complex environments with both very hot, dense gas and very cold molecular gas that has cooled out from the hot component. Optical emission-line filaments are found in almost all cluster cores where strong cooling is observed in the X-ray. In the past 15 years we have established that cold molecular gas is threaded through this ionised material, and ALMA has shown that the two phases are intricately linked. Recently, however, we have used VLT/MUSE spectroscopy to identify a cold gas filament which is only visible through its narrow NaD absorption lines, projected against the BCG starlight of the low-redshift cluster A3716. Optical line emission is barely detectable even with the high sensitivity of MUSE, perhaps indicating a very low temperature in the cloud. Here, we propose ALMA observations to determine whether there is molecular gas associated with the A3716 "Sodium Shadow", and whether the cold gas extends behind the BCG where NaD absorption cannot be observed. The possibility that molecular gas may be present in cluster cores that we have overlooked by relying on optical emission line selection would have far-reaching implications. | Early-type galaxies, Galaxy groups and clusters | Galaxy evolution | 2020-01-04T07:24:11.000 |
| 2410 | 2018.1.00432.S | 10 | Molecular line polarization tracing the 3D magnetic field of a Hot Core | Models of massive star formation show that magnetic fields have significant effects: preventing fragmentation, slowing cloud collapse, influencing the accretion disk, and feedback. However the magnetic field parameters are still poorly understood, in particular at small scales and at the initial stages of massive star formation. Thus, we intend to map the magnetic field in the high-mass YSO IRAS 18089-1732. This can be done by observing the polarisation of thermal lines, that arises in the presence of a magnetic field (Goldreich-Kylafis effect). A 3D map can be obtained because each velocity channel of a molecular transition traces a different depth within the protostar. By using a polarised line radiative transfer code, we will reconstruct the magnetic field morphology modelling the emission of several bright lines, such as SiO, a well known jet tracer. By comparing this data with our previous observations of polarised masers and dust, we will draw a complete picture of the magnetic field morphology covering the jets, the disk and the envelope. This will be a key result to clarify the influence of magnetic field in the cloud collapse, accretion and feedback processes. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2021-07-28T00:00:00.000 |
| 2411 | 2011.0.00727.S | 0 | Mapping the nitrile chemistry and dynamics of Titan's thermosphere | The Cassini space mission has shown that Titan's atmosphere is a complex system involving strong interactions between chemistry and dynamics. Titan's stratosphere and lower mesosphere (150-500 km) is currently explored in details by Cassini/CIRS. At the top of the atmosphere, the thermosphere (900-1200 km) is currently explored by Cassini/INMS, but with a scarce sampling in latitude, altitude and local time. In between, Titan's mesosphere/lower thermosphere region from 500 to 1000 km remains largely unexplored by Cassini. The main goals of this proposal are (i) to map the HNC(4--3) and HCN(4--3) lines in the upper atmosphere (500-1000 km), in order to constrain the chemistry, temperature and dynamics in this poorly known region. (ii) to take benefits of the large bandwidth of ALMA to simultaneously map other nitriles (HC3N and CH3CN) and search for an as-yet undiscovered nitrile (DCN). | Solar system - Planetary atmospheres | Solar system | 2014-08-12T13:54:00.000 |
| 2412 | 2022.1.00664.S | 12 | Fragmentation and Disk Formation in Low-metallicity Star Formation | Although massive stars play essential roles through cosmic history, the formation of massive stars is still poorly understood, particularly in the low-metallicity regime like the earlier epoch of the Universe. Massive protostars in the Large Magellanic Cloud (LMC) are the best targets to investigate massive star formation in the low-metallicity environment. We propose high-resolution observations of seven LMC massive protostars with the resolution of 0.1", i.e., 5000au. This is the first-ever LMC project to resolve the dynamics smaller than the protostellar-core scale of 0.1pc. We will investigate the characteristics of core fragmentation by the 870um continuum, and study the dynamics of the envelopes (infalling flow and disk rotation) with the hot-core molecular lines (SO, SO2, CH3OH) and the outflows with CO and SiO. By comparing these results with the corresponding Galactic observations, we will examine the universality of massive star formation in different metallicity environments. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2025-01-02T00:37:56.000 |
| 2413 | 2021.1.00027.S | 35 | An ALMA Survey of Molecular Gas in the Host Galaxies of Fast Radio Bursts | Fast radio bursts (FRBs) are millisecond bright radio pulses, whose nature still remains a mystery. Because the link between progenitors and specific environments are expected, observations of host galaxies are essential to understand their nature and constrain models. To understand the physical properties of ISM, we propose CO(2-1) observations of FRB host galaxies. The final goal is to obtain molecular gas properties of all well-localized FRB hosts known to date. Observations of four hosts are done or ongoing in previous studies, and we will target the rest 7 hosts in this program. This work will represent the largest and complete sample of FRB hosts, allowing a statistical and comprehensive examination of molecular gas properties for the first time. If FRBs originate from massive stars or their remnants, an adequate quantity of molecular gas is expected for producing the progenitors. By comparing with environments of other populations, we derive characteristic properties (gas fraction, star-formation efficiency, depletion time) in FRB hosts. Because no CO detection has been reported so far, this work would be the first case of detecting molecular gas in FRB hosts. | Starbursts, star formation | Active galaxies | 2023-09-20T12:20:31.000 |
| 2414 | 2021.2.00079.S | 36 | Complete Molecular Gas Coverage in Nearby Low-Luminosity AGN | The interplay between a galaxy and its central supermassive black hole (SMBH) is one of the key open questions in understanding galaxy evolution. We propose to obtain short-spacing coverage using the ACA of the Seyfert/LINER galaxies in the NUGA-South sample previously observed by ALMA in Band 7. The centers of these seven nearby galaxies were observed in CO(3-2) at angular resolutions up to 0.06 and the tunings also cover critical tracers of dense molecular gas. However, most NUGA-South galaxies lack the short-spacing coverage necessary to infer robust gas masses and to maximally leverage the existing archival data. With full coverage of the spatial scales in these galaxies, we will be able to 1) Place these AGN galaxy centers on integrated scaling relations and search for indications of AGN-driven suppression of star formation, 2) Trace the gas inflows to the centers on larger scales, and 3) Search for diffuse molecular gas and outflow components, and 4) Robustly measure key line ratios, including line ratios suggested to act as AGN diagnostics. All of these goals require the high surface brightness sensitivity and short-spacing information from ALMA's ACA+TP modes. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2023-09-09T21:11:29.000 |
| 2415 | 2013.1.01004.S | 24 | Revealing the secrets of VLA1623: an in-depth look into the earliest star formation stage | Multiple protostellar systems are common in the early stages of star formation. While fragmentation is agreed to be the main mechanism of formation, most of what is known comes from continuum observations but continuum alone can not answer the recurrent questions of multiple star formation: do all detected sources belong to the observed system? what are the relative evolutionary stages? what influence do companions have on each other? what is the dependence on the temperature structure of the core? In addition, of interest to star formation in general, is the formation of rotationally supported disks. Disks are crucial to star formation, but the question of when do they form and what enhances their formation still remains. VLA1623 is a triple non-coeval system in rho Ophiuchus which shows some interesting extremes in star formation: the youngest Keplerian disk and the coldest source. The proposed observations will help us to address the questions of early disk formation, source membership in a system and temperature structure of the cloud and its effect on disk formation and fragmentation. | Low-mass star formation | ISM and star formation | 2015-10-02T14:44:18.000 |
| 2416 | 2015.1.00222.S | 99 | Disk demographics in Lupus | We propose to survey the gas and dust in 98 protoplanetary disks in the nearby Lupus star-forming region. This is a complete sample of all known optically visible stars with large infrared excesses and stellar masses > 0.1 solar. We will observe the CO, 13CO and C18O 2-1 lines and have developed models to derive gas masses. We will image with a resolution that corresponds to 20AU in radius while maintaining sensitivity over the entire disk. We expect to detect almost all disks in the continuum and measure sub-Jupiter masses of gas. From the resolved images, we will determine radial profiles of the gas, dust, and gas-to-dust ratio, as well as characterize the prevalence of dust holes and asymmetries. This efficient, large, and complete survey will provide an unbiased view of the gas and dust properties in young planet-forming disks, and is complemented by our VLT optical-infrared spectroscopic survey of the host stars. | Disks around low-mass stars | Disks and planet formation | 2017-12-18T21:28:28.000 |
| 2417 | 2022.1.01498.S | 14 | The multi-faceted impact of galaxy-scale radio jets | We propose to map the molecular gas impacted by a kpc-scale jet in a nearby radio AGN to study the effect of the jet on star formation on large scales. In the proposed target, CO(2-1) data from public ALMA observations show that the jet is driving a mild molecular outflow confined to the sub-kpc region, while at larger (kpc) distances the gas is being pushed aside by the radio lobes in a more gently way. These different types of jet-ISM interaction are predicted by numerical simulations implying a change in the coupling between the radio plasma and the ISM as the radio jet expands throughout the host galaxy. The observations will provide a test of these simulations and will improve our view of the role of radio jets in AGN feedback. We request CO(1-0) and CO(3-2) observations with 0.2 arcsec spatial resolution. Combined with the available CO(2-1) data we will trace line ratios in the gas across the radio source and beyond. These ratios have been shown to be effective diagnostics for the conditions in the molecular gas and will allow us to study the overall impact of the AGN on star formation on small and large scales. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-06-30T10:32:45.000 |
| 2418 | 2018.1.01281.S | 26 | A mysterious population of massive quiescent galaxies at z ~ 4 | Quiescent galaxies with little ongoing star formation are now routinely identified out to z ~ 2.5, but it is still unclear when the quenching of star formation first occurred. Using the new ZFOURGE near-infrared imaging survey, we have found a substantial population of quiescent galaxies at z ~ 4, whose existence is at complete odds with state-of-the art cosmological simulations. However, while the rest-frame UV-through-optical colors give little indication of star formation, there remains the possibility of significant dust-obscured activity; it is possible that these galaxies are not quiescent at all. Existing far-infrared maps from Spitzer, Herschel and SCUBA2 are not deep enough to set stringent constraints, even with stacking. Here we propose to observe a sample of 8 candidate quiescent galaxies at 3.6 < z < 3.8 with ALMA band 6 in order to measure their thermal dust continuum and star-formation rates down to 6 Msun/yr per object (3sigma), thereby revealing their true nature. If quiescent galaxies exist at these high redshifts, then we have found the highest-quality candidates; ALMA presents the best opportunity to confirm or to rule out this important but elusive population. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-07-23T00:00:00.000 |
| 2419 | 2015.1.01558.T | 18 | Particle Acceleration in GRB Afterglows | GRBs are powered by stellar-mass black holes that eject matter at ultra-relativistic velocities. This makes them ideal laboratories to study particle acceleration processes. Up to now the Swift satellite has detected ~1000 GRB afterglows but only 20-30 were bright enough for extensive follow-ups from radio to X-ray wavelengths to provide crucial constraints on the radiation processes. These analyses were however limited to bright afterglows, which could introduce a bias in the relative importance of different radiation processes. Thanks to ALMA's supreme sensitivity, both the peak and the faint end of the GRB luminosity function could now be probed at sub-mm wavelengths. We propose to observe one GRB with a peak flux of ~300 µJy at 93 and 339 GHz at 5 different epochs each. The peak flux is about 1 dex fainter than of previously studied GRBs and more representative of the bulk of the GRB population. We will complement these observations with optical and NIR data to model the broadband spectral energy distribution. We will identify the dominant radiation process and characterise its key properties, study the ambient density profile and the dynamics of the ultra-relativistic jet. | Gamma Ray Bursts (GRB) | Cosmology | 2017-09-16T18:19:39.000 |
| 2420 | 2019.1.00061.S | 27 | Probing Cosmic Dawn: Estimating the Stellar Ages of z~9 Galaxies | Determining the period when the first galaxies emerged from a dark intergalactic medium represents a fundamental milestone in assembling a coherent picture of cosmic history. Recent surveys of z~7-9 galaxies have revealed a population whose red Spitzer IRAC colours either indicate contamination from intense optical emission lines or the presence of a Balmer break due to a mature stellar population. Accurate redshifts are needed to distinguish between these two hypotheses. One example was confirmed via [O III] emission with ALMA at z=9.11 whose Balmer break indicates the onset of star formation occurred as early as z~15±2. We propose to follow up the only further similar z~9 candidate accessible with ALMA to determine if this initial result is a representative indicator of when galaxies first emerged from the Dark Ages. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2021-02-27T12:14:50.000 |
| 2421 | 2019.1.00854.S | 10 | The counter rotating molecular torus of NGC 1068 | Taking advantage of ALMA's longest baseline configuration, we have resolved the obscuring, molecular torus of NGC 1068 into nested, counter-rotating disks. The inner (r < 1.2 pc) disk associates with the well-known water vapor megamaser disk, and the outer torus extends to r ~ 8 pc from the central engine. Although we find evidence that the disks are undergoing Keplerian rotation, the outer torus appears asymmetric and not yet kinematically relaxed. We propose that the outer torus is kinematically young, having formed from a more recent fueling event from gas falling out of the host galaxy. We propose ALMA observations to compare the isotopologue ratios of the inner disk and outer torus as a test of uncommon provenance. The proposed observations will also permit constraints on the molecular excitation of the (presumably) X-ray dominated, dense molecular gas surrounding the central engine. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-11-03T17:23:40.000 |
| 2422 | 2011.0.00902.S | 0 | VLA1623B: a First Core candidate? | First Cores (FC) are the transient phase between prestellar cores and Class 0 protostars. They are characterized by low luminosities, short lifetimes and capable of driving slow collimated outflows. Not surprisingly they are difficult to detect. FC are key in understanding the earliest stage of protostellar formation. Our recent studies using SMA data towards VLA1623 suggest that VLA1623B is a FC candidate. We propose to confirm that VLA1623B is a FC candidate by detecting the early astrochemical molecule DCO+ and N2D+. ALMA is the only instrument that can resolve the two components and has enough sensitivity to detect the emission with reasonably short timescale (~ 1hr). | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2013-06-15T06:49:00.000 |
| 2423 | 2015.1.01256.S | 11 | The mass-loss rates of the most massive stars | We propose Band-4 and Band-6 continuum observations of the young cluster NGC 3603 to measure the mass-loss rates of its massive-star population (with all the objects at the same distance). We anticipate to detect several dozens of O-type stars, and we will measure their mass-loss rates in the most accurate way possible. We shall also derive the mm-fluxes and mass-loss rates of the 3 very massive hydrogen burning Wolf-Rayet WNh stars (A1, B, and C) that are present in the cluster center, and we shall test whether the theoretical predictions of an upturn in the mass-loss rates of optically thick winded WNh stars is confirmed. This would have important consequences for the evolution and fate of the most massive stars in the Universe. We note that ALMA is the only instrument with the required sensitivity and spatial resolution to carry out this project. | Main sequence stars | Stars and stellar evolution | 2018-02-09T13:44:44.000 |
| 2424 | 2017.1.00886.L | 2268 | 100,000 Molecular Clouds Across the Main Sequence: GMCs as the Drivers of Galaxy Evolution | For 30 years, our observational understanding of extragalactic giant molecular clouds and their star formation has been built on case studies and small galaxy samples. We propose to harness ALMA's stunning survey speed and imaging power to move this field into the era of big surveys. With 75 hours of main array time, we will image CO(2-1) at 1" resolution across the disks of all 80 massive (log M_star > 9.75 M_sun) star-forming galaxies in the local volume (d<17 Mpc). This will yield >100,000 GMCs spread across a sample of galaxies and environments that is truly representative. Using in-place machinery, we will use these data to measure the key ingredients for a synthetic model of star formation: (1) the molecular cloud population (mass function and dynamical state), (2) the efficiency per free fall time, (3) the cloud lifetime and destruction time, and (4) the scale and mechanism for star formation self-regulation. Measuring these quantities as a function local environment and host galaxy will provide the fundamental link between molecular clouds, star formation, and galaxy evolution. | Surveys of galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2020-02-02T00:00:00.000 |
| 2425 | 2018.1.00329.S | 291 | Dissecting the Main Sequence of Star Formation with [CI](1-0) Observations | Atomic carbon [CI] has been put forward as an excellent tracer of the ISM conditions and the gas mass reservoir (Mgas) of star forming galaxies (SFGs). However its potential has not been fully exploited as [CI] detections have predominalty been restricted to inhomegenious samples of local and high-z stabursting systems (SBs). We propose CI[1-0] observations for a well characterised sample 30 of SFGs at z~0.6 that lie along and above the main sequence of star-formation (MS), have excellent photometric coverage and robust spectroscopic redshifts. The proposed observations will extend for the first time the L(IR)-L(CI) relation to parameter space that is currenlty devoid of [CI] detections of normal SFGs. From these [CI] detections we will 1) further explore recent evidence (from our Cycle 4 [CI] survey of z~1.2 SFGs) of larger L(CI)/L(IR) ratios between normal SFGs and SBs 2) derive Mgas estimates independent of the conventional CO and dust based methods and most importanlty 3) tackle the still open debate of increased gas fractions vs increased star formation efficiencies between MS and SBs as the main driver of the enhanced star formation in the latter. | Starbursts, star formation | Active galaxies | 2020-08-08T13:08:59.000 |
| 2426 | 2015.1.01134.S | 24 | The youngest massive cluster RCW38 formed via cloud-cloud collision: Revealing the core mass function in the region of O stars in the making | It is said in a review article by Zinnecker and York (2007) "Rapid external shock compression (i.e., supersonic gas motions) generating high column densities in less than a local free-fall time rather than slow quasi-static build-up of massive cores may be the receipt to set up the initial conditions for local and global burst of massive star formation... but such a discussion is beyond the scope of this review.[1]" It was not explored how the supersonic gas motion realizes massive-star formation until the MHD numerical simulations by Inoue & Fukui (2013) which have shown massive core formation in supersonic colliding molecular flows[2]. Recent observations strongly suggest that such supersonic gas motions are indeed triggering massive star formation by cloud-cloud collisions in super star clusters and Spitzer bubbles. We propose ALMA observations of the on-going high-mass star formation in the collision-compressed layer in RCW38. These observations will allow us for the first time to witness the clump mass function of proto O stars. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-03-23T10:53:28.000 |
| 2427 | 2017.1.00797.V | 0 | Imaging the Shadow of a Supermassive Black Hole: Event Horizon Telescope Observations of Sgr A* | The Galactic Center supermassive black hole, Sgr A*, subtends the largest angular size of any black hole in the universe. Previous 1.3-mm observations with the Event Horizon Telescope (EHT) have detected Schwarzschild-scale emission from Sgr A* but have lacked the sensitivity and baseline coverage to produce images. In April 2017, we observed Sgr A* for the first time with the full EHT+ALMA array. Although these data are not yet available, the demonstrated technical performance at all sites strongly motivates expanded observations. In particular, as the only EHT target with intra-hour variability and daily flares, Sgr A* is the most promising source to study variability near a black hole. We propose for 31.5 hours observing Sgr A* with ALMA joining the EHT, equivalent to 3 imaging tracks. These observations will double the recorded bandwidth of 2017 and give a factor of 4.5 increase in frequency coverage (214.1-230.1GHz), enabling a direct probe of magnetic field strength near Sgr A* via Faraday rotation. They can confirm persistent image features, such as the black hole "shadow", and can give the sharpest view ever obtained of the structure and dynamics near a black hole. | Galactic centres/nuclei | Active galaxies | 2021-04-21T14:37:58.000 |
| 2428 | 2013.1.00600.S | 2 | Resolving the Protostellar Population of the Massive Protocluster NGC6334I | Understanding the accretion process in massive protostars requires high resolution centimeter through (sub)millimeter imaging to distinguish dust emission from ionized gas and to probe the molecular gas kinematics down to scales smaller than the accretion radius (~500 AU). Our recent 0.3" JVLA and 0.6" SMA observations of the deeply-embedded massive protostellar cluster NGC6334I have revealed two line-rich hot cores, a mysterious 7 mm submillimeter line-free continuum source, and a faint 6 cm continuum source coincident with water masers (JVLA1). We propose to use ALMA to observe NGC6334I with 0.2" resolution (320 AU at 1.6 kpc) in a range of high excitation diagnostic lines at Band 6 (1.3 mm). At this wavelength the dust opacity should be low enough for spectral line emission to escape and reveal details of the innermost structures (untrue at higher frequencies). We will also obtain a Band 3 continuum image at 0.4" resolution aimed at detecting previously unknown hypercompact HII regions that may be lurking within this protocluster. Our measurement of the Band 3 to Band 6 spectral index will be essential to discern the nature of JVLA1 and any other new sources that we detect. | High-mass star formation | ISM and star formation | 2016-12-04T15:22:26.000 |
| 2429 | 2022.1.01427.S | 5 | First look of a close-separation, z~2 dual quasar with ALMA | The search for dual supermassive black holes is of immense interest in modern astrophysics. When two galaxies merge, the central black holes may evolve into a bound binary and further inspiral until they eventually coalesce into a single merger product. If these black holes are actively accreting during the inspiral phase, they will be observed as a dual quasar. To-date only a handful of dual quasars have been confirmed. As a result, their properties remain unknown, especially those at z>1. Among many ongoing questions in the galaxy black hole co-evolution model, the role of galaxy mergers and quasar activity remain debated. We propose to study one kpc-scale dual quasar at z=2.17 at the peak epoch of galaxy formation. These early dual quasars may represent the progenitors of low redshift binaries. Thus, this dual quasar serves as a unique case study of merger-quasar relations, quasar feedback, and binary evolution. This observation will be the first of its kind. We propose ALMA Band 4 observations of the cold molecular gas phase, traced by the CO(4-3) emission, to identify signs of spatially resolved molecular gas flows to address quasar fueling and feedback in dual quasars. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2024-06-07T16:27:04.000 |
| 2430 | 2017.1.00824.S | 38 | The quest for the building blocks of the warm dust species in the inner wind of R Dor | The mechanism launching a wind in oxygen-rich (O-rich) AGB stars is not yet understood. Pulsations and radiation pressure on newly formed dust grains are known to be important. However, the grains that can sustain the high temperatures close to the star do not absorb stellar photons efficiently and hence cannot accelerate the gas out of the stellar gravitational potential. The formation of large micron-sized grains is proposed as a solution to this dilemma. Large grains at a distance of ~1.5 stellar radii (Rstar) are now detected in O-rich AGB stars, but their chemical constitution remains unknown. ALMA can for the first time spatially resolve the inner wind structure of a very close-by O-rich AGB at a spatial resolution equalling half the stellar radius (!) and unravel step-by-step the formation of dust grains via the molecular depletion factors. We will observe R Dor, the star with the second largest apparent size right after the Sun. By observing key molecular species contributing to the formation of dust grains (AlO, AlOH, SiO), we will deduce the efficiency of gas depletion by condensing onto dust grains and hence will answer which type of grains forms already at 1.5 Rstar. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2019-03-01T04:53:33.000 |
| 2431 | 2017.1.00419.S | 19 | The Hunter's Gift: A Bounty of Forming Disks to Further Our Understanding of Protostellar Evolution | The formation of a protostar and its Keplerian disk remains a poorly characterized process, but ALMA now provides an opportunity for significant progress. These forming disks also hold the key to measuring the most fundamental parameter of newborn stars, their masses derived from the Keplerian disk rotation. The measurement of protostar masses and the properties of forming disks for large ensembles of systems is essential to solidifying our knowledge of star and planet formation. Our ALMA Cycle 3 survey of 330 protostars in the Orion molecular clouds at 0.13" (50 AU) resolution yielded >100 well-resolved continuum images of apparent protostellar disks. We propose to observe a sample of 20 disk candidates around 10 Class 0 and 10 Class I protostars, drawn from a representative range of luminosities (0.4 L_sun to 480 L_sun). With these observations, we will confirm whether or not each disk is Keplerian, using molecular line tracers (primarily C18O J=2-1), measure the change in mass and mass accretion between the Class 0 and I phases, how much the disk properties depend on stellar mass, and how much disk structure evolves from Class 0 to Class I and later stages. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2021-01-30T22:04:42.000 |
| 2432 | 2024.1.00530.S | 0 | Measuring the Star Forming Potential of the Galactic Bar Dust Lanes | The dust lane features within the Galactic Bar are thought to mediate the flow of material from the Galactic Disk towards the Galactic Center, fueling the extreme environment found within the Central Molecular Zone (CMZ). Therefore, the study of galaxy bars is important for our understanding of how galaxies evolve and investigating the initial conditions of the gas before it accretes into the CMZ. The midpoint of the Dust Lanes (M4.7-0.8) was recently observed using the GBT, targeting the lower transitions of non-metastable NH3 lines - a dense gas tracer. These observations revealed multiple dense substructures with the cloud - indicating the cloud could be rich with dense gas, similar to clouds in the CMZ. Here we propose to target several dense gas tracers at the midpoint of the Dust Lanes (M4.7-0.8) that are abundantly detected in the CMZ and were recently detected in the ALMA ACES program. We use a similar spectral setup as ACES to address the question: How do the physical, chemical and dynamical properties of star-forming regions in the Galactic Bar Dust Lanes differ from those in the disc and Galactic center? This is a resubmission of a previously accepted Cycle 10 project. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-10-31T04:55:45.000 |
| 2433 | 2018.1.00306.S | 342 | Characterizing X-ray driven molecular chemistry in the disk population of Orion | The chemistry of protoplanetary disks sets the initial compositions of newly formed planets. Disk abundances typically evolve slowly, over timescales spanning 0.01-1 Myr. Consequently, it was a surprise when ALMA observations taken over a single year significantly varied in H13CO+ emission, an X-ray sensitive molecule. Given the known X-ray variability of disk-hosting stars, one promising theory is variable X-rays are driving variations in the composition of the disk. The present proposal aims to test this hypothesis by observing a group of ten disk-hosting young stars in Orion with both ALMA and Chandra, to definitively catch the smoking gun of X-ray driven chemistry. If confirmed, the proposed program is likely only the beginning of what is essentially a new field of time domain astrochemistry. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2020-01-19T04:45:01.000 |
| 2434 | 2015.1.00606.S | 78 | Redshift 6 host galaxies of 10^8 solar mass black holes | Our goal is to understand the evolution of galaxies and black holes at the earliest epoch. We thus propose to observe five z=6.0-6.5 quasars in [CII] and rest-frame 160 micron continuum known to have black hole mass ~10^8 solar masses. The three quasars of this kind already detected with ALMA in [CII] and dust continuum are consistent with the relation [CII] to far-IR (FIR) luminosity ratio versus L_FIR found for bolometric-luminosity matched galaxies at lower z and suggest that L_[CII] can be used a high-redshift star formation estimator, even in the presence of a moderate AGN. Additional, moderately faint z~6 quasars are needed to confirm this behaviour. Our main goal is a comparison of the star formation rate and accretion rate in the context of models for black hole and galaxy evolution in the first billion years since the Big Bang. We also want to confirm the lack of significant offset from the local M_BH versus galaxy velocity dispersion relation of the CFHQS+SDSS z~6 quasar sample and understand the constraints placed on models by this observation combined with the relatively low measured star formation rates. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-03-01T02:50:11.000 |
| 2435 | 2022.1.00172.S | 88 | Searching for H2O megamaser disks in the early Universe | Water megamasers are powerful tools to measure masses of supermassive black holes (SMBH) and derive angular distances to the host galaxies at high precisions (~4%), thus constraining critical cosmological parameters. The recent detection of the 380GHz H2O maser line in two z>3.5 starburst galaxies revealed that this line is significantly stronger than the canonical 22 GHz or other submm water maser lines, suggesting that it is among the best extragalactic maser tracer found so far. Moreover, the high-velocity satellite lines of the 380GHz maser detection are likely tracing the accretion disk around the SMBH, a necessary precursor to derive SMBH masses and distances. To build upon these findings, we propose the first survey of the 380GHz H2O megamaser in a sample of twelve well-studied starburst galaxies at 2 | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2024-04-03T14:50:27.000 |
| 2436 | 2023.1.00327.S | 0 | ANGELS in Band 9 and 10: Short-wavelength observations of 21 bright Herschel galaxies | Recent redshift searches of DSFGs are enabling full spectroscopic follow up; however, exploiting this with ALMA is challenging, as the large overheads favour deep studies of individual sources. The ANGELS project circumvents this problem by targeting continuum bands while including as many lines as possible. This project has successfully mapped Bands 3 through 8 on a pilot survey of 21 sources. Here, we ask for 1.5hrs of Band 9 and 1.5 hrs of 10 observations to provide the most detailed view on the dust continuum of these well-studied sources, improving upon Herschel astrometry by two orders of magnitude and providing pixel-to-pixel maps of the dust temperature inside these DSFGs. These observations will vastly increase the Band 9 (by 50 %) and 10 (by 400%) extragalactic short-wavelength legacy of ALMA, and form the foundation of dust temperature studies for Herschel galaxies. Simultaneously, we will target 6 atomic lines ([NII], [OI], [CII] and [OIII]) serendipitously. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-09-13T19:08:05.000 |
| 2437 | 2018.1.00397.S | 76 | WISDOM: Measuring High-mass Supermassive Black Holes using CO Kinematics | The known empirical correlations between supermassive black hole (SMBH) mass and host galaxy properties appear to break down at the highest SMBH masses. This could be due to a dominant merger growth channel, but whether such a mergers are dry or wet, and whether this really explains the divergence from a lower mass M-sigma cannot be determined from existing data due to large uncertainties in SMBH mass measurements and mass-size biased selection. Our previous work has shown that it is straightforward to measure SMBH masses by resolving the Keplerian rise of the galaxy rotation curves, using ALMA to trace the kinematics of the CO gas. As part of the mm-Wave Interferometric Survey of Dark Object Masses, we have in low-resolution observations identified promising targets in this high-mass region. Measuring their SMBH masses will elucidate how different evolutionary paths lead to the most massive black holes. We also spatially resolve their molecular clouds, allowing us to study how the properties of these vary in galaxies of different types. This proposal is an improved resubmission of a C-grade cycle-5 project, for which only one object was satisfactorily observed. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2020-12-03T18:33:14.000 |
| 2438 | 2017.1.00258.S | 98 | Spatially resolved dense gas diagnostics in the Close AGN Reference Survey (CARS) | The dense molecular material in the centres of galaxies provides fuel for massive star formation, and also acts as a reservoir for accretion (powering active galactic nuclei; AGN). If we can understand the information encoded in the emission lines of dense gas tracers then they can provide critical information on the nature of the physical processes ongoing in the centres of galaxies. In this proposal we propose to obtain ALMA Band 7 observations for seven representative galaxies from the Close AGN Reference Survey (CARS), which span the full range of galaxy types and properties. Our immediate goal is in order to map the important diagnostic emission lines HCN(4-3), HCO+(4-3) and CS(7-6) together with dust continuum emission. With these data we will be uniquely positioned to compare molecular diagnostics with maps of the ionised gas excitation, stellar population information and hot gas properties all derived at the same spatial scale across the face of normal AGN host galaxies. This will enable us to take an important step forward for spatially resolved dense gas diagnostic studies, and shed light on how normal AGN supress star formation across the universe. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy chemistry | Active galaxies | 2019-06-04T19:44:37.000 |
| 2439 | 2023.A.00021.S | 18 | [CII] confirmation for a massive dusty star-forming galaxy at z~7.5 | We request 0.5 hr ALMA DDT in Band 6 to confirm the possible z=7.458 redshift of a very massive (Mstar~10^11 Msun), highly star-forming (SFR~2000 Msun/yr) dusty galaxy. If confirmed, this would be the highest redshift object of its kind and pose a challenge that current models of massive galaxy formation will need to match. Using state-of-the-art datasets in the COSMOS field, we obtained multiple pieces of evidence that mutually agree on z_spec=7.458, including a well-constrained photo-z~7.7 using JWST NIRCam+MIRI photometry, and a robust line detection in ALMA 3mm spectrum that indicates CO(7-6) at z=7.458. However, the lack of a second line detection leaves the highest-z nature tentative. The requested observations will unambiguously confirm its redshift with robust [CII] detection, and provide us with an ideal laboratory for testing models of massive galaxy formation and cosmology. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-10-04T19:57:53.000 |
| 2440 | 2022.1.00346.S | 36 | Probing the origin and evolution of hydrogen fluoride in galaxies until z~5 | The aim of this proposal is to explore the evolution of the abundance ratio between molecular hydrogen (H2) and hydrogen fluoride (HF) at high redshift. This will provide a solid constraint on the currently actively debated mechanisms of fluorine production in the interstellar medium (ISM), witnessing the ramp-up of chemical enrichment of the ISM thanks to a unique sample of 9 high redshift galaxies (2 already observed and 7 that we aim to observe in this cycle with ALMA) at 2.5 < z < 5. In addition, due to the exothermic reaction between the fluorine and the molecular hydrogen (F being the only element that reacts with H2 in this way), HF may prove to be very useful to explore systematics and scatter in H2 measurements and calibrate other tracers over a wide range of conditions. | Sub-mm Galaxies (SMG), Gamma Ray Bursts (GRB) | Galaxy evolution | 2024-01-09T21:30:36.000 |
| 2441 | 2022.1.01553.S | 0 | Grains or pebbles? A follow-up on dust particle sizes in TW Hya | For its unique properties, TW Hya is generally considered as the protoplanetary disc template. For this reason, it was extensively studied from the observational point of view. Recently, archival continuum observations of TW Hya in band 3, 4, 6 and 7 were used to estimate the properties of the disc dust grains. Surprisingly, these data are compatible with two scenarios: either large mm/cm-sized grains, or small particles, sized tens of microns. No conclusive answer has been given yet. We propose to observe TW Hya in band 10, after showing that high-frequency observations have the potential to distinguish between these two scenarios. | Disks around low-mass stars | Disks and planet formation | 2025-10-15T09:22:02.000 |
| 2442 | 2018.1.01625.S | 12 | HH4647 Disk Formation and Outflow Launching around a Protobinary System | Formation of binary is common in low-mass star formation. However, how protostars accrete in the presence of a companion is not completely understood. Outflows play an important role in removing angular momentum from the disks to allow accretion toward central protostars. But the outflow launching in a protobinary system is also unclear. We propose ALMA Band 6 observation with a resolution of 40 au to map the circumbinary/circumstellar disks around the protobinary system HH 46/47. In previous ALMA observations, we have shown that this system is driving a highly ordered molecular outflows as well as a collimated jet. The requested resolution will allow us to resolve the protobinary (separation of 120 au) and maybe even probe the circumstellar disks. The proposed observations will probe the substructure morphologies and motions inside the circumbinary disk, including how it feeds the two circumstellar disks and how it connects to the larger infalling/rotating envelope. It will also help to constrain the launching region of the wide-angle outflow. This observation will provide important clue for understanding disk and outflow formation in protobinary systems. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2021-01-17T21:56:05.000 |
| 2443 | 2018.1.01030.S | 9 | A Moment of Truth with ALMA CN Zeeman Observations: Is Disk Accretion Really Driven by Magnetic Fields? | Magnetic fields are believed to be essential to the process of accretion in circumstellar disks. Attempts to measure the strength and morphology of disk magnetic fields through dust continuum polarization have so far proven unsuccessful; the observed polarization patterns in the disk could be better explained by scattering and radiative alignment. We propose to obtain measurements of the magnetic field strengths in the disks of AS 209 and V4046 Sgr through measurements of Zeeman splitting in the CN 2-1 transition line. Zeeman splitting offers a direct probe of the line-of-sight magnetic field without contamination from scattering and radiative alignment. Observations of the disks magnetic fields will offer evidence for or against current theories of magnetically driven accretion. | Debris disks | Disks and planet formation | 2020-11-01T18:24:13.000 |
| 2444 | 2017.1.00235.S | 19 | Rise of the Titans: Unveiling the Nature of a Binary Hyper-Luminous Starburst at Redshift 6 | We propose detailed ALMA imaging to characterize the nature of ADFS-27, the most distant binary hyper-luminous starburst known, at a redshift of 5.655. We have recently discovered this rare, gas-rich, dusty dual "maximum starburst" system with ALMA and Herschel, consisting of two merging galaxies 2kpc in diameter, separated by only 9kpc. We here request [CII] imaging at 600pc resolution (matching proposed HST observations of the stellar components) to investigate the mechanisms that drive and fuel these dense warm starbursts, and to measure dynamical masses and gas fractions based on detailed dynamical modeling. We also request observations of the J_upper=8-10 CO lines to measure the density and kinetic temperature of the high-excitation gas component associated with the nuclear starbursts, revealing the conditions for star formation. We will also cover OH+ and CH+ J=1-0 and two high-level H2O lines "for free", which we will use to investigate the presence of molecular outflows and the intensity of the infrared radiation field in ADFS-27. This study will be key to properly place ADFS-27 into context with cosmological simulations and models of starburst galaxies at different epochs. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2020-02-23T01:48:44.000 |
| 2445 | 2016.1.00880.S | 18 | Characterizing a Kuiper Belt analog carved out by a newly discovered brown dwarf companion | We propose to obtain the first high-resolution submillimeter map of the debris disk surrounding the nearby young F-type star HD 50571. The disk has been marginally resolved by Herschel but its radial structure remains highly uncertain. Using the Gemini Planet Imager, we have recently discovered a brown dwarf companion interior to the debris disk, making this system an ideal one to empirically study the process of gravitational sculpting of a debris disk by substellar object. This process is often used to interpret asymmeries in high-resolution images of debris disks to infer the mass and orbital properties of unseen planets. However in cases where the perturber remains undetected, significant ambiguities remain in the analysis. Thus, ALMA observations of HD 50571 now offer us a unique opportunity to test our understanding of this process and for a perturber mass that has no equivalent in the Solar System. The results of these observations will therefore inform many other studies in this field, well beyond this particular system. | Debris disks | Disks and planet formation | 2019-05-25T20:58:48.000 |
| 2446 | 2016.1.00929.S | 72 | A Challenge towards the First Detection of Interstellar Glycine | We propose to observe G10.47+0.03 with five lines of Glycine (NH2CH2COOH) in band4. We have found that G10.47+0.03 has the richest abundance of methylamine (CH3NH2), a precursor to glycine, whose abundance is about one order of magnitude higher than that in SgrB2(N). Since the observed abundances of CH2NH and CH3NH2 can be well explained with the model by Garrod (2013), the first detection of glycine would be plausible with the brightness temperatures of about 160mK, based on the predicted abundance of glycine by Garrod (2013). G10.47+0.03 shows narrower linewidth than SgrB2(N), smaller probability of line contamination would be expected. Once successful, we will be able to open a new era of astrochemistry and astrobiology in that many researchers would join in finding other amino acids and\/or other prebiotic molecules. | Astrochemistry | ISM and star formation | 2018-04-07T17:38:05.000 |
| 2447 | 2015.1.00741.S | 246 | Revealing Binarity and the Youngest Disks in Oph | We propose a survey of multiplicity toward all known Class 0 and Class I/II protostars in Oph (75 sources). Using a dust continuum sensitivity of 0.1 Jupiter masses, we will probe the binarity of these sources from 15 AU out to 1000 AU, which well samples the peak of the main-sequence and pre-main sequence binary separation distributions (30 and 60 AU) toward the younger protostars for the first time. Combining with our Perseus VLA 8mm continuum survey, we will have 130 sources (great statistics) in two clouds, which will mitigate concerns of environment. This is the largest and most complete high-resolution millimeter-wave survey of protostellar binaries ever undertaken and will significantly improve our understanding of the formation mechanisms and prevalence of close binaries during the early stages of star formation. In addition, the survey will also be perfect for detecting protostellar circumstellar disks. There are currently only 3 disks in Class 0 sources known, so this project will increase the number of candidate Class 0 and I disks, help resolve the current controversy on early disk properties, and constrain disk formation scenarios that are hotly debated. | Low-mass star formation | ISM and star formation | 2017-06-14T19:05:51.000 |
| 2448 | 2017.1.01575.S | 52 | Witnessing the transition from protoplanetary to debris disk in the archetype hybrid disk HD21997 | Planet formation implies that the dust levels observed around young protoplanetary disk should drop to debris disk levels before gas dispersal takes place. This picture has only recently become observationally supported by the increasing number of detections of high levels of CO around debris disk host stars. These hybrid disks provide a unique opportunity to study protoplanetary disk dispersal and debris disk birth. We here propose ALMA Band 7 imaging of the archetype hybrid disk around the 30 Myr-old star HD21997, the only known system surrounded by debris-like dust levels that has been confirmed to host a CO disk with mass comparable to that of TW Hya. Cycle-0 observations suggest a dust disk extending far beyond the CO disk, a feature unprecedented for protoplanetary disks. Through spectro-spatially resolved ALMA observations of the outer dust and C18O disks, we will distinguish between the 2 possible origins of the observed dust morphology: 1) planetesimal formation with secondary dust production induced by outside-in FUV photoevaporation or 2) no need for planetesimal formation, with leftover primordial dust in an anemic protoplanetary disk dominating the observed emission. | Debris disks, Disks around high-mass stars | Disks and planet formation | 2019-05-29T18:28:29.000 |
| 2449 | 2015.1.00106.S | 21 | Formation of O Stars by Accretion of Ionized Gas | Massive protostars must accrete 40 to 60 Msun to become O stars, but they begin core hydrogen burning well before reaching their final masses. At a stage equivalent of an O star, the surface temperature is high enough to create a significant HII region around the star. This poses an interesting theoretical question: How does accretion proceed through the pressure differential between the cold molecular and hot ionized gas? This ALMA proposal aims at imaging both molecular and ionized gas at high angular resolution and high sensitivity to resolve the molecular and ionized accretion as well as the ionized outflow in a protocluster forming HII region G10.6-0.4. The new data will test the theoretical model that we developed on ionized accretion. This ALMA study will pave the way for observations of smaller hypercompact HII (HCHII) regions excited by individual or a small group of O stars in the near future thanks to the availability of the ALMA long baselines. | High-mass star formation, HII regions | ISM and star formation | 2018-08-15T09:18:41.000 |
| 2450 | 2018.1.00745.S | 28 | Fast expansion in a hypercompact HII region | We have recently detected strong emission in the H30alpha recombination line from a hypercompact HII region embedded in a hot molecular core. By mapping the line peak velocity we find a large (22000 km/s/pc) velocity gradient across the ionized gas, increasing from SW to NE. The same gradient has been revealed in the surrounding molecular core, though less prominent (~300 km/s/pc). We want to find out the relationship between the two gradients. We propose two scenarios: (a) the ionized gas expands isotropically and becomes collimated when interacting with the surrounding core; (b) both the ionized and molecular line emission trace the same molecular outflow, whose expansion is collimated at all scales. The velocity field inside the HII region is expected to be different in the two cases, when observed at higher angular resolution (0.045") than our previous ALMA observations (~0.2"). Depending on the scenario confirmed, (a) or (b), we will establish if outflows from massive stars can be accelerated by confined stellar winds, or can be powered by ionized accretion flows. | High-mass star formation, HII regions | ISM and star formation | 2021-02-05T17:49:24.000 |
| 2451 | 2012.1.00725.S | 12 | Probing the formation of wide separation planets with ALMA | A major unsolved question of planet formation is whether wide-separation giant planets form `in situ' or form closer to the star and migrate outward in a later stage. In this proposal we request ALMA observing time to directly address this question by imaging the circumstellar disks around the Herbig Ae stars MWC 758 and HD 142527. We selected these two sources because recent near-infrared scattered light observations revealed spiral arms and arcs, which are thought to results from the dynamical interaction between the disk and giant planets orbiting at more than 30 AU from the central star. These structures extends for more than 1" and can be spatially resolved by ALMA cycle 1 observations. By imaging the optically thin dust continuum emission we aim to investigate if the observed spiral arms and arcs correspond to density enhancements in the dust spatial distribution, and, in particular, if they trace spiral density waves. By observing the molecular 13CO and C18O (3-2) emission we aim to investigate the signature of the infrared structures in the gas kinematics and density. The combination of the proposed ALMA observations with the available infrared images will provide an unprecedented tool to study the structure of these two outstanding circumstellar disks and to investigate the formation of wide-separation planets. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2016-07-31T05:13:40.000 |
| 2452 | 2016.1.00393.S | 13 | Chemical evolutions of GMCs while crossing the spiral arm in the nearby galaxy M 83 | Recent ALMA observations are unveiling the spatial variations in chemical properties of molecular gas in external galaxy disks, which might be useful to understand the evolutions of giant molecular clouds (GMCs) further because specific evolutionary stages of GMCs can be traced by specific molecular lines (and their ratios). We propose to observe molecular lines including 13CO(1-0), C18O(1-0), CS(2-1), and CH3OH(2-1) simultaneously toward the spiral arm of M 83 in order to study the evolution of GMCs while crossing the spiral arm in terms of chemical properties. Since the CH3OH abundance could be enhanced by mild shock such as spiral shock waves, we expect to observe the high CH3OH/13CO ratio for unvirialized GMCs in the initial stage of the evolution. On the other hand, for evolved and virialized GMCs which have crossed the spiral arm, we expect to observe the increase in C18O/13CO and CS/13CO ratios and the decrease in CH3OH/13CO ratio because the dense-gas and massive-star formation occurring in such GMCs can enhance C18O and CS, but CH3OH is dissociated by UV radiation from massive stars. We will verify the chemical evolution of GMCs by cycle-4 observations. | Spiral galaxies, Galaxy chemistry | Local Universe | 2018-05-22T09:41:34.000 |
| 2453 | 2016.1.00719.S | 38 | Unraveling the multiscale emission of the unique gamma-ray emitter PMN J1603-4904 with ALMA | Gamma-ray sources are the most energetic objects in the Universe. The unique extragalactic jet PMN J1603-4904 is one of the most exciting candidates of a young radio galaxy detected at gamma-rays, of which only one other example is known so far. Hence, it is a perfect laboratory to study high-energy emission and jet formation processes of newly born active galaxies. We propose ALMA continuum observations (band 3, 4 & 6) to perform the first ever study of the large-scale radio morphology which is estimated to be about 0.6 kpc (about 0.2 arcsec) in size. This study can only be achieved by ALMA and is crucial to confirm the young radio galaxy classification. The data will play a decisive role in closing the resolution gap between our VLBI and Chandra images and will lead to the first multi-scale picture of PMN J1603-4904 which is essential to test jet models. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-03-23T14:11:08.000 |
| 2454 | 2021.1.00276.S | 6 | Is Disk Polarization Different in Single and Multiple Systems? | Although nearly all single star circumstellar disks have dust polarization emission that is consistent with scattering, two examples of circumbinary disks are instead consistent with polarization from the magnetic alignment of dust grains. This may be caused by complex structures in the circumbinary disks or a change in grain growth or something not yet known. The source L1448 IRS3B is a prime example of a circumbinary disk. This very young, deeply embedded protostar has a beautiful spiral structure in a massive circumbinary disk; L1448 IRS3 has been caught in the act of fragmenting. We propose to use Band 4 and 7 dust polarization observations to determine if the circumbinary disk is polarized by magnetic grain alignment or by scattering. If it is magnetic grain alignment, we will compare the magnetic field morphology to the circumbinary structures and to MHD models. If it is scattering, we will use models to constrain the dust grain growth. These observations will push our understanding of dust polarization, characterize circumbinary disk sources, and build a polarization portfolio of disks with multiple protostars. | Low-mass star formation | ISM and star formation | 2024-01-06T19:26:35.000 |
| 2455 | 2022.1.00152.S | 6 | Resolving the controversy of the stellar IMF in SNL-1 using molecular gas dynamics | The stellar initial mass function (IMF) appears to be universal in our own Galaxy, but evidence is mounting for systematic variation in extragalactic environments, especially in the most massive early-type galaxies (ETGs). However, despite various converging lines of evidence, significant uncertainties and discrepancies remain. We propose here a focused investigation of SNL-1, a z=0.03 ETG lensing a background galaxy at z=1. SNL-1 is part of a small sample of low-redshift lenses that should have heavy IMFs according to spectroscopic analyses, but where the lensing mass does not show a corresponding excess stellar mass. Uniquely among the lens sample, SNL-1 is amenable to molecular gas measurements. ALMA Cycle-6 data show much larger central CO velocities than expected from the lensing mass, if the mass-to-light ratio is constant. Reconciling these two robust tracers calls for additional central mass either from an over-massive black hole, or a steep inner gradient in the IMF. The two solutions cannot be distinguished at the resolution of the existing data. A short additional ALMA observation with longer baselines will resolve the IMF controversy for this crucial benchmark galaxy. | Early-type galaxies | Galaxy evolution | 2024-06-21T21:29:17.000 |
| 2456 | 2017.1.01584.S | 22 | The SIze and Albedo of New Horizons Distant Kuiper Belt Target (15810) Arawn | Following its flyby of the Pluto system in July 2015, NASA's New Horizons mission embarked on a campaign to exploit the unique capabilities of a spacecraft traveling in the outer Solar System by making observations of Kuiper Belt objects (KBOs) at viewing geometries unattainable from Earth. Although the sizes and albedos of the largest of these distant KBO targets are well-known, the size and albedo of (15810) Arawn (1994 JR1) are constrained only loosely by membership in its dynamical class, yet these fundamental physical quantities are within reach of ALMA. Measurement of the geometric albedo of Arawn, when combined with the phase integral measured by New Horizons will provide the spherical albedo of this resonant KBO. The spherical albedo is the ratio of total flux reflected in all directions from a planetary surface to the total solar incident flux; therefore its measurement enables an evaluation of the thermal energy budget of a Solar System surface. This combination of ALMA and New Horizons results, will enable the first comparisons of the surface properties of a Plutino (using the spherical albedo) to properties of the surfaces of other well-studied Solar System objects. | Solar system - Planetary surfaces, Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2019-07-19T15:51:02.000 |
| 2457 | 2019.1.01461.S | 11 | The ALMA revolution: Physical conditions of the most distant quasar host galaxy | The recent discovery of a quasar at z=7.5 enables detailed studies of the interstellar medium of a massive galaxy just 680Myr after the Big Bang. Our exploratory ALMA cycle 5 observations of this quasar are already remarkable. We detect spatially resolved [CII] at high significance and [OIII], [OI] and [NII] at 3-5sigma, while we report limits on [CI] and multiple CO lines (with a tentative stack detection). These data already provide crucial insights on the physical conditions of this system (two papers submitted). Capitalizing on our previous exploratory effort, this proposal is carefully designed to conclusively characterize the interstellar medium of this redshift-record quasar host. We will observe [OIII], [OI], CO(7-6), CO(8-7) and [CI] to 1) Determine the density, gas/dust ratio, metallicity, ionization, radiation field and molecular mass. 2) Confirm an intriguing spatial offset between the [CII] and [OIII] lines in the available data. 3) Detect [CII] emission from the most distant absorption system known at z=6.8. This quasar provides a unique laboratory for ALMA to push detailed studies of star formation and the interstellar medium to the highest accessible redshift. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-06-10T21:11:04.000 |
| 2458 | 2017.1.00999.S | 365 | Complex molecules and rare isotopes in Nova 1670 | We propose to image the remnant of Nova 1670 (CK Vul), the first documented nova-like object. Its eruption in 1670-72 was observed by contemporary observers and modern analysis indicates a strong similarity of Nova 1670 to eruptions of red novae, i.e. a class of stars that erupt in a merger event. Although a stellar collision and coalescence explains many features of CK Vul, its history and current state are not understood. Using single-dish telescopes, we recently discovered molecular emission of the remnant at mm and submm wavelengths. The spectrum is remarkably rich in lines of rare isotopologues and polyatomic organic molecules. The isotopic and chemical composition of the gas is most peculiar and deepens the mystery of CK Vul. We propose to map a large number of its molecules in order to constrain better the chemical and isotopic compositions. They will help us to understand the current state of CK Vul and the nature of the binary system that merged in 1670. Mergers are much more common than supernovae and their isotopic yield may be important for the origin of isotopes in the Galaxy. | Evolved stars - Chemistry, Transients | Stars and stellar evolution | 2019-06-06T20:59:18.000 |
| 2459 | 2013.1.00745.S | 9 | Assessing the nature of the ISM at high-z through multiple detections of fine-structure lines | The physical and chemical properties of the interstellar matter (ISM) and their redshift evolution are crucially important to understand the evolution of galaxies. Rest-frame optical diagnostics are not useful at z>3.5 due to the limited NIR atmospheric transmission window, that prevents us from investigating the quantitative assessment of the ISM in high-z galaxies. However, the superb sensitivity of ALMA enables us to observe some fine-structure lines at high redshifts, that can be used to study the nature of the ISM. Here we focus on a strong [CII] emitter, BR 1202-0725 at z=4.69. Thanks to its high [CII] luminosity and optimal redshift, we can observe [NII]122, [OI]145, and [NII]205 (in Band 8, 7, and 6) within a realistic observing time. By comparing the obtained emission-line flux ratios with our theoretical models, we will investigate the gas density, metallicity, and possible truncation of the PDR, in this system. Since this system consists of a SMG and a QSO, we can also study the possible AGN effects on the ISM properties. This project will bring us brand-new clues to understand the baryonic evolution of galaxies and the IGM cosmic reionization. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2016-07-13T19:04:39.000 |
| 2460 | 2017.1.01059.S | 1 | Chromospheric brightness and the magnetic field in solar active regions | In the chromosphere of the Sun two mechanisms are believed to be contributing to heating: acoustic heating, mainly due to shocks, and magnetic heating, primarily via reconnection. In recent years spectroscopy in the UV and extreme UV has provided new insights into magnetic heating through reconnection, including the formation of plasmoids in current sheets as an aspect of the transition from slow to fast reconnection. It is hard to decipher the actual thermal structure in the chromosphere during these reconnection events from UV/EUV observations alone, since the corresponding lines are not formed in thermal equilibrium. High-resolution radio observations with ALMA will provide key information on the energetics that are missing from the traditional line observations: the brightness temperature observed by ALMA provides a much cleaner diagnostic of the electron temperature in the solar chromosphere, not available previously at the required spatial resolution. We request ALMA Band 6 observations of an active region in order to determine the relative contributions of magnetic and non-magnetic heating to the energetics of the chromosphere. | The Sun | Sun | 2019-10-15T11:10:32.000 |
| 2461 | 2012.1.00441.S | 0 | 3D Structure of an Ionized Jet from a Massive Protostar | We propose to make the first measurement of the 3D structure of an ionized jet from a massive protostar. The selected target is IRAS 18162-2048 (HH 80-81), one of the brightest objects in its class and the clearest example of a massive protostar with a disk and a magnetohydrodynamically launched jet. The proposed ALMA observations will map the mm hydrogen recombination-line emission in two transitions that can be observed simultaneously in Band 3. These observations will give direct information about the line-of-sight velocity and density structure along the jet. Combined with the available information that for more than 20 years has been obtained on the proper motions of the jet on the plane of the sky, we will be able to determine the 3D structure of the jet and constrain theoretical models for accretion-ejection in star formation. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2015-08-01T23:31:12.000 |
| 2462 | 2016.1.00052.S | 23 | Scrutinizing the properties of AGN dusty molecular torus | We propose ALMA band 6 high angular resolution (<0.07") HCN 3-2 observation of the nucleus of the prototypical type-2 AGN, NGC 1068. Our ALMA Cycle 2 data with 0.1" x 0.2" spatial resolution clearly identified compact dense molecular gas emission which is believed to be associated with the putative AGN dusty molecular torus, by separating from nearby spatially extended bright emission in the host galaxy. This is a very important milestone to scrutinize the properties of dusty molecular torus which are still poorly understood observationally. In this proposal, we aim to spatially resolve the compact torus molecular emission to investigate its dynamics and to obtain an important clue about its origin. Additionally, we aim to investigate the possibly detected emission in our ALMA Cycle 2 data which may bridge between the torus and bright eastern knot in the host galaxy, to confirm if we are witnessing molecular gas inflow from the host galaxy to the torus. Since our observing strategy is based on our available ALMA Cycle 2 data, the feasibility to accomplish our science goals is expected to be high. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-11-12T08:40:18.000 |
| 2463 | 2021.2.00046.S | 0 | Probing accretion of ambient cloud material into the massive filament in NGC6334 | We propose to observe CO(2-1), 13CO(2-1), and C18O(2-1) toward the NGC6334 filament and its surroundings to reveal the mass growth of this massive filament. The ALMA Cycle 3 observations in N2H+(1-0) revealed that the NGC6334 filament contains 5 velocity-coherent fiber-like sub-structures. The properties and velocity sub-structures of the massive NGC6334 filament are very similar to those of the low-mass star-forming filament B211/213 in Taurus, suggesting similar formation/fragmentation processes in both cases. What is not yet clear observationally is whether the NGC6334 filament is growing in mass through gravitational accretion of ambient cloud material as the Taurus filament does. We aim to investigate this issue by comparing ALMA CO and its isotope line observations with a gas accretion model developed for Taurus. For this purpose, we need to map the ambient gas surrounding the filament over a ~4pc extent at a spatial resolution of ~0.05pc to probe velocity gradients down to < ~0.1pc scales. The proposed observations, which can be done only with 7m+TP, will provide key insight into the process of filamentary growth in a massive star-forming region. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2023-06-08T08:58:48.000 |
| 2464 | 2016.1.01355.S | 58 | Compaction in Obscured AGN Hosts | The processes driving the co-evolution of galaxies and their super-massive black holes largely remain a debated issue in extragalactic astrophysics. Using HST imaging, we found that the radial I-band light profile of obscured AGN host galaxies at z~1 is more compact than that of star-forming sources at similar redshift and stellar mass, and that it is not due to the contribution of a passive stellar component. It could thus pinpoint an increased activity of central star formation possibly triggered by a phase of gas compaction. Indeed such AGN hosts are actively forming stars, but where this star formation occurs is still unconstrained. We thus request high-resolution ALMA Band 7 images to derive dust emission maps of 10 obscured AGN hosts. This will allow us constraining their star formation surface density without AGN contamination, and investigating if the spatial distribution of young stars follows that of the compact visible disk. We will address whether the obscured black hole accretion phase is related to galaxies experiencing a compaction of their gaseous component, which could play a key role in the final quenching mechanisms driving the formation of passive red sources. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-01-25T13:57:08.000 |
| 2465 | 2011.0.00851.S | 0 | The Origin of the Destroyed Minor Planet at G29-38: a Main Belt or Kuiper Belt Analog? | G29-38 is the prototype and brightest example of a white dwarf orbited by rocky debris from a tidally-destroyed minor planet. Because this warm debris orbits within 1 solar radius, the parent body must have originated in a more distant region populated by a substantial number and mass of remnant planetary bodies. We propose ALMA observations to identify the orbital region from which the parent body originated, by detecting and spatially-resolving cold dust from within this remnant planetesimal belt. The primary science goal is to distinguish between a Main Belt and Kuiper Belt analog. The proposed observations should yield the first image of planetary debris around a white dwarf, and provide insight into the fate of planetary systems at A- and F-type stars. The bulk chemical composition of the destroyed parent body can be determined via spectroscopy of the metal-polluted stellar atmosphere, and the ALMA observations will identify the formation region associated with this chemistry. With these data we will possess a nearly complete picture of a rocky (and perhaps icy) minor planet around another star; both where it formed and its bulk composition. Only white dwarfs offer this opportunity and ALMA observations of G29-38 represent an ideal way to highlight this scientific potential. | Debris disks, White dwarfs | Disks and planet formation | 2013-02-14T15:43:22.000 |
| 2466 | 2017.1.00775.S | 57 | Mapping all phases of the ISM in a normal reionisation-epoch galaxy | Finding and characterising the galaxies that reionised the universe is a central goal for ALMA. Here we propose to follow up our successful detection of the first really bright [CII] line in a reionisation-epoch galaxy (A1689-zD1) with the detection of the [OIII] and CO emission lines. These detections will allow us to get a complete picture of the ISM of a galaxy at this era for the first time by characterising its ionized, atomic and molecular gas and its dust at high significance. The galaxy is the best target currently known for such observations from both a SNR point of view, and because it is a normal (i.e. sub-L*) galaxy at this epoch, one of the only galaxies spectroscopically confirmed in the epoch of reionisation without Ly-alpha emission. These data will allow us to constrain the atomic gas column and the oxygen abundance in the galaxy as well as comparing these data to the dust-to-gas ratio and, due to the lensing magnification, to do all this at a spatial resolution sufficient to pick out individual super star clusters. | Starburst galaxies | Active galaxies | 2019-04-12T23:59:40.000 |
| 2467 | 2019.1.00477.S | 171 | ColdSINS: an ALMA cold gas census of the deepest near-IR IFU+AO sample of z~2 star-forming galaxies | We propose a census of the cold gas content from sensitive ALMA 870um continuum observations of 35 z~2 galaxies from SINS/zC-SINF, the deepest and highest resolution near-IR IFU sample in existence. This sample, probing the star-forming galaxy population over two orders of magnitude in mass, has exquisite 0.15" resolution AO-assisted SINFONI data of the Halpha+[NII] line emission and deep HST near-IR imaging, giving maps of the kinematics, star formation, metallicities, outflows, stellar light and mass on ~1kpc scales. These substantial campaigns (650 VLT hours + 126 HST orbits) led to several breakthroughs that helped shape our current understanding of galaxy evolution. For a modest 15.0 hrs investment, ColdSINS will obtain the first direct constraints on the mass and extent of the cold gas in these galaxies at high sensitivity (RMS=0.05mJy) and ~0.9" resolution. This knowledge is also prerequisite to future high-resolution ALMA follow-ups. This is a resubmission of a Cycle 6 proposal ranked in the top quartile but not scheduled due to oversubscription. We will provide the community with the reduced ALMA data, complementing the already released reduced SINFONI+AO sets. | Galaxy structure & evolution | Galaxy evolution | 2021-04-06T13:15:42.000 |
| 2468 | 2018.1.00191.S | 54 | Shut It Down: Probing Molecular Feedback in z=4-5 Dusty, Star-forming Galaxies | One of the most important realizations of the last fiteen years is the vital role that feedback must play in the evolution of galaxies, particularly at the massive end (Mstar > 10^11Msun). Star formation appears to have been efficiently "quenched," but the processes by which quenching occurs are poorly understood. Theoretical models invoke feedback from AGN and/or star formation to disrupt, expel, or heat the gas and prevent further star formation. Recent observations and circumstantial evidence suggests that the bulk of star formation in the earliest quiescent galaxies took place in dusty, star-forming galaxies (DSFGs) at z>4. We propose to test models of feedback and the evolutionary connection between DSFGs and quiescent galaxies by spatially and spectrally resolving massive molecular outflows in 7 z=4.2-5.3 galaxies. Our observations will constrain the outflow geometry and mass loss rates, allowing us to determine whether quenching is due to gas depletion or gas removal. Our targets span a factor of 12 in star formation rate (SFR) and 30 in SFR surface density, giving a large dynamic range to constrain outflow scaling relations and match local work at high-z. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2020-08-08T22:08:27.000 |
| 2469 | 2015.1.00979.S | 1 | Imaging the wind that clears protoplanetary disks | Recent theoretical and observational work suggests that star-driven photoevaporation is, together with viscous accretion, the main physical process through which protoplanetary material is cleared out. Yet, evidence for photoevaporative winds is scarce, limited to spatially unresolved profiles from forbidden lines and excess cm emission on top of the dust thermal emission. We propose to obtain the first spatially resolved image of a photoevaporative wind and measure the extent of the wind. These data will unambiguously prove the existence of photoevaporative winds and provide an empirical estimate of the rate at which protoplanetary material is lost. | Disks around low-mass stars | Disks and planet formation | 2017-01-26T01:34:47.000 |
| 2470 | 2019.1.00039.S | 7 | The surface magnetic field of AGB stars: Zeeman measurements of atmospheric OH | Magnetic fields appear ubituitous throughout the circumstellar envelopes (CSEs) of evolved asymptotic giant branch (AGB) stars. However, the magnetic field strength on the surface of AGB stars is very poorly constrained. It is the magnetic field near the surface that will possibly affect the stellar mass loss and hence evolution. So far only one AGB star has had its surface magnetic field measured using observations in the visible and very few other AGB stars are accessible with this technique. Maser observations have revealed strong magnetic fields in the CSEs, but it is unclear if these measurements can be extrapolated to the star. Recently, ALMA discovered non-masing excited OH in the atmosphere of AGB stars. The magnetic succeptibility of OH means that we now have a direct probe of the magnetic field near the stellar surface. Here we propose to detect the magnetic field of the AGB star W Hya for which maser observations imply a field of several Gauss near the surface. If we can confirm this field we can, for the first time, benchmark the maser measurements in the CSEs with the surface field and determine if the magnetic field has the power to affect the mass loss mechanism. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2022-12-23T17:06:09.000 |
| 2471 | 2019.1.01813.S | 7070 | SODA: a flux-limited Survey of Orion's Disks with ALMA | The observational study of protoplanetary disk evolution is essential for understanding planetary system origins. ALMA surveys of disks in nearby regions show a dependence of the disk mass distribution on cloud age and environment, but the small number of regions that have been observed limits our understanding. We propose an unbiased, unresolved survey of 882 disks down to 2 M_earth around young stars in groups of different densities, and in a scattered population, along the tail of the Orion A cloud, in ALMA Band 6. These observations are key in disentangling the effects of time, environment, and initial cloud conditions on disk formation. | Disks around low-mass stars | Disks and planet formation | 2021-03-19T21:30:39.000 |
| 2472 | 2023.1.00698.S | 60 | ALMA-GECKOS: Completing the multiphase view of gas in edge-on galaxies for a MUSE large program | We propose for 12 m and ACA observations of 12 galaxies from the GECKOS sample, a MUSE large program targeting nearby edge-on galaxies. These will be combined with 3 that are fully covered in the ALMA archive. Our primary aim is to measure extraplanar emission of CO gas. The amount of gas that exists above the midplane of a galaxy regulates star formation, and the cold gas phase is likely the main mass component of galaxy winds that generate the extraplanar gas. We aim to create the first sample of resolved (~100 pc) outflow observations of both molecular and ionised gas. We will develop scaling relations between outflow properties and the launching sight of the disk, which directly test modern theories of feedback and winds. Beyond outflows, GECKOS will execute a comprehensive analysis of edge-on galaxies with extremely deep observations with the VLT/MUSE integral field spectrograph. ALMA data will make critical improvements to dynamical modelling, and informed comparison to stellar populations analysis and the evolution of bars. As the only deep IFS+ALMA sample of edge-on galaxies our program will provide a unique legacy data set with broad impacts for many years. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2024-12-06T14:13:51.000 |
| 2473 | 2015.1.00717.S | 11 | [CI](1-0) may trace H_2 better than CO(1-0): a sensitive test on molecular outflows | We propose high sensitivity observations of the [CI]3P1-3P0, 13CO(1-0) and CS(2-1) emission lines in the local AGN-host LIRG NGC 6240. We aim to explore the capability of the [CI](1-0) line to trace the ``bulk'' of H_2 gas, both in the outflow and in the star forming disk of NGC6240, and in particular of its most diffuse and coldest phase, and compare it to the more commonly employed 12CO(1-0) and 13CO(1-0) gas tracers. Our analysis will have a great legacy value for future, high redshift studies, because at z>2 the lowest-J CO transitions are not observable with ALMA. We will also investigate the denser phase of H_2 through the CS(2-1) line and examine whether the outflow entrains high density gas, which is the primary fuel for star formation. The recent discovery that star formation-powered cosmic rays can very effectively destroy CO (but not H_2) makes the proposed observations even more promising since cosmic rays escape from star forming disks, and are expected to do so preferentially along the directions of the powerful H_2 outflows. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-04-13T11:50:10.000 |
| 2474 | 2022.1.00827.S | 11 | The physical conditions, spatial structure, and the expanding velocity of the dust formation zone of IRC+10216 | ALMA high spatial resolution observations of IRC+10216 separated by a two years time interval show resolved continuum and gas structures around the star (1-10 stellar radii) that are moving with different velocities depending on the distance to the star, and that the mass loss process is proceeding through the emission of fragments of shells. We propose to study the innermost zone (1-10 R*) of IRC+10216 through the systematic observation of the continuum emission and of a significant number of vibrationally excited lines of abundant species such as HCN, HNC, SiS, SiC2, and SiO (up to 15000 K in energy). The highest angular resolution of ALMA in bands 6 and 7 (0.015-0.025") is requested to study the region where dust molecular seeds, and dust itself, are formed. These new observations will also permit to track the spatial movement of the gas and the dust and to derive an expanding velocity of the innermost envelope as a function of the distance to the star. We expect to obtain a unique data set from which the physical conditions and spatial structure of the gas and dust across these inner regions will be derived | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2024-11-09T20:46:41.000 |
| 2475 | 2019.1.01229.S | 200 | First Systematic Study of Dense Molecular Gas in Quasars | The star formation of massive galaxies is suspected to be modulated by the accretion power of massive black holes (BHs) via some feedback mechanisms. Galaxy star formation is intrinsically linked with the amount of dense molecular gas. Knowledge of dense gas properties in quasar host galaxy, therefore, provides crucial insight to BH-galaxy interaction. Meanwhile, few study of dense gas focus on quasar host galaxies. Following our Cycle 5 ALMA survey of CO(2-1) line of z<0.1 quasars, we propose to measure HCN (1-0) and (3-2) transitions of 13 quasars with ALMA 7m array observations. The dense gas fraction (HCN/CO ratio) and the scaling relation of dense gas mass and star formation rate will be compared with nearby star-forming, starburst, and Seyfert galaxies. HCO+ and HNC lines are expected to be detectable along with HCN as a bonus. With the best knowledge of multiwavelength quasar properties at hand, we will use the line ratios to diagnose the physical condition of dense gas. This is a first systematic study of dense gas with a representative sample of quasars. It will provide important references for future quasar studies at nearby and distant universe. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-01-03T19:51:09.000 |
| 2476 | 2016.1.00031.S | 80 | The molecular absorber toward B0218+357 | Molecular absorption toward bright continuum sources is a powerful method to study the physico-chemical properties of gas even in distant galaxies. The molecular absorber at z=0.89 toward PKS1830-211 has been intensively studied thus far, resulting in the detection of more than 45 different species and several of their isotopologues. These molecules at z=0.89 have been used as powerful cosmological probes, e.g., for determining the cosmic microwave background temperature evolution with redshift, the invariance of fundamental constants of nature, and the chemical evolution of the Universe via measurements of isotopic ratios. Here we propose to turn to the ONLY other known absorber to date similar to PKS1830-211, that located at z=0.68 toward B0218+357. The set of proposed observations is designed to address the nature of the absorbing gas, measure isotopic ratios of carbon, nitrogen, oxygen, sulfur, and chlorine, and derive the cosmic microwave background temperature at z=0.68. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy structure & evolution | Cosmology | 2018-06-15T01:19:40.000 |
| 2477 | 2016.1.00782.S | 273 | What hinders massive star formation in a massive quiescent giant molecular cloud at low metallicity | Massive stars are used to estimate star formation rates (SFRs) in distant galaxies, but the calibrations (e.g. initial mass function, dust calorimetry) are assumed to be independent of environment. Studies have shown that SFR decreases with metallicity, so we need to investigate the detailed physical conditions required for massive star formation (MSF) at low Z. In the LMC (1/3Zo), 3 GMCs in the N159 region have similar size and mass, but very different star formation (N159E,W that we observed in Cycle 1 are forming clusters, N159S is quiet). Our 10pc resolution APEX multi-J CO mosaics reveal 10-15pc-sized filaments in N159S, but their properties are still mysterious until we resolve the parsec-sized structures that actually participate in star formation. Our kinematic analysis of N159S shows that all scales except the smallest resolvable (7 pc) are much more turbulent than virialized systems including N159E+W. Again, we have to resolve the heirarchical structure down to gravitationally dominated scales to determine if N159S is globally resisting star formation, or if it is collapsing, but only on anomalously small scales. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2018-03-29T21:55:17.000 |
| 2478 | 2013.1.01231.S | 8 | The Fine Structure of an Extreme, Lensed Starburst Galaxy at z=5.7 | We propose to observe a full diagnostic suite of five far-IR fine structure lines in an extraordinary starburst galaxy at the end of cosmic reionization. Through the power of gravitational lensing, our observations will measure the metallicity, radiation field, density, kinematics, and AGN effects with effective resolution of a few hundred parsecs, which has only been possible to date in the nearest star-forming galaxies. SPT0346-52, at z=5.7, already has high-resolution maps of the dust continuum and low-J CO emission, as well as integrated measurements of mid-J CO, [CII], and full radio-to-IR SED coverage. These observations effectively complement Herschel studies of local ULIRGs, and extend the study of these lines to the first Gyr of cosmic history. The high sensitivity, high resolution studies made possible by ALMA will address several key questions about the first stages of galaxy evolution, including the production of heavy elements, stellar and AGN feedback mechanisms, the energetics of the ISM, and the dynamics of the first galaxies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2016-02-02T13:17:04.000 |
| 2479 | 2015.1.00196.S | 64 | Zooming in on the parsec-scale structure of CO gas at low metallicity and its relation to star formation | The star formation rate is proportional to the surface density of molecular gas, for a wide range of metallicities. Models predict that the structure of CO-emitting gas should change with metallicity and radiation field: extended CO emission and CO "clumps" should shrink as metallicity decreases or radiation field strength increases. This effect has never been directly observed before, and models of CO formation have not been put to a test. Additionally, the effects of those changes on the star formation process, which occurs in dense, CO-emitting gas, are unknown. We propose to obtain deep maps of two transitions (1-0 and 2-1) of three CO isotopes (12CO, 13CO, and C18O) in 6 regions of two low-metallicity galaxies, the LMC and the SMC. These observations will allow us to test CO photo-chemical models by providing deep maps of the pc-scale structure, column density, thermal, and chemical state of the CO-emitting gas at two low metallicities and a range of radiation fields. By comparing the CO maps to pc-resolution tracers of star formation, specifically 24 micron emission and young stellar objects, we will bridge the gap between Galactic and extragalactic star formation studies | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-10-05T17:18:15.000 |
| 2480 | 2022.A.00029.S | 11 | Simultaneous ALMA and JWST Monitoring of Sgr A* in the August 14-21, 2023 Window | Variable emission provides a tool for probing the structure and physics of the accretion flow in Sgr~A*, with significant impact on our understanding of massive black holes in the nuclei of other galaxies. To address this issue, we propose to observe Sgr~A* for 8h at submm simultaneously with an already scheduled JWST re-observation using NIRCam (2.1 and 4.8 microns) in the August 14-21, 2023 window. The unique opportunity of observing with NIRCam at two simultaneous wavelengths and ALMA at submm addresses the connection between Sgr~A*'s IR and submm flare emission by using synchrotron and adiabatic models of the variable emission. In addition, with its remarkable sensitivity and low background noise, the proposed measurements probe the hypothesis that the same population of particles are responsible for producing NIR and submm emission. Modeling the submm and NIR variability is critical to EHT's goal of improving future imaging of Sgr A*. Lastly, submm IQUV polarization measurements combined with NIR flaring provide a fantastic opportunity to determine the evolution of the magnetic field on event horizon scale sizes in the context of expanding hot spots orbiting Sgr A*. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2024-09-01T19:06:37.000 |
| 2481 | 2016.1.00292.S | 36 | A final answer on the carbon isotopic ratio in starburst environments with ALMA | The 12C/13C isotopic ratio is a good tracer of the chemical evolution of the ISM. Within the Galaxy we observe a clear gradient with galactocentric distance which evindence the different age of the stellar population in the outer Galaxy. However, after more than two decades of measurements, this ratio is still poorly constrained in the extragalactic ISM. Though observations point towards a high 12C/13C ratio in local starbursts and even higher ones at high-z, measurements may be biased both by limited sensitivity and the opacity of the more abundant isotopologues used. Moreover, recent measurments in local starbursts suggest that this ratio has been underestimated. ALMA, for the first time, and making use of optically thin tracers, can finally provide a final answer to this question. Here we provide a direct measurement of the carbon isotopic ratio based on the C18O/13C18O. We note that the 12C/13C ratio is commonly used to derive other atomic ratios (such as O, N, and S) and therefore a precise measurement of the carbon isotopic ratio is needed and finally at grasp with ALMA. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2018-04-12T04:25:40.000 |
| 2482 | 2019.1.01210.S | 2 | Mapping the Inner Edge and Interior Cavity of a Kepler-Analog Circumbinary Protoplanetary Disk | The Kepler space mission discovered several circumbinary planets around short-period (P < 40 days) binary stars, indicating that circumbinary planets form readily. A key input to any circumbinary planet formation theory is the radius at which the dynamical tides from the (possibly eccentric) binary orbit truncate the inner edge of the protplanetary disk. Through moderate resolution observations in Cycle 4, we have discovered that a circumbinary disk, whose orbital properties broadly match the sample of Kepler circumbinary planets, hosts a large dust hole ~25 au in radius. The inner edge of the hole is azimuthally asymmetric, and is quite a bit further out in the disk than one would predict from classical truncation arguments alone. It is an open question as to whether the gap is indeed the result of influence from the binary, is carved by one or more giant planets, or is a consequence of the advanced age of the system (16 Myr). We propose for high resolution (0.02"), sensitive dust continuum observations to map the asymmetry of the disk edge and determine whether the cavity is truly devoid of dust emission or contains the dynamical signatures of giant planets. | Disks around low-mass stars | Disks and planet formation | 2022-10-05T14:28:13.000 |
| 2483 | 2022.1.00067.S | 20 | Cold halo around the massive Spiderweb Galaxy | Using low-surface-brightness mm techniques, a giant halo of cold molecular gas was detected surrounding the massive Spiderweb Galaxy in a proto-cluster at z=2.2. An estimated 10^11 solar masses of molecular gas is detected in CO(1-0) across ~70 kpc, where it fuels in-situ star formation within the intra-cluster medium. ALMA cycle-3 (12m) and 5 (ACA) data revealed the presence of widespread atomic [CI], but the surface-brightness sensitivity is insufficient to compare the [CI] with the CO and Ly-alpha across the full extent of the halo. We propose ACA observations of both [CI] lines (and CO(4-3), CO(7-6) in the same tuning) to image the atomic gas across the >100 kpc halo environment of this high-z protocluster. Combined with the 12m data of CO(4-3), CO(7-6), CI lines and ATCA CO(1-0) the data will be used to investigate the true extent and morphology of the CO-rich and CO-poor gas. A joint CO/CI SLED modelling is a unique tool to determine the physical status of the molecular gas, its total mass and the dominant source powering the intracluster medium. | Galaxy Clusters | Cosmology | 2024-06-07T00:12:55.000 |
| 2484 | 2016.1.00826.S | 30 | HD 97048: A Planetary system in the making | HD 97048 is one of the brightest disks at 850 micron in the sky, and a prime target to observe at high angular resolution to look for ring systems such as recently observed in HL Tau and TW HYa. In our cycle 2 band 7 observations we detect radially a disk hole up to 50 au, and disk gaps at ~90 and ~260 au. Supplementary data point at more structure inside the disk gap. By observing this disk at 0.06" resolution at band 7, we will resolve features ~10 au in size, while supplementary cycle 2 data allows us to trace structures out to ~2.5 arcseconds in radius. 13CO J=3-2 observations will, in concert with existing 12CO J=3-2 data, give a measure of the density and temperature inside and out of the gaps and hole. Both the dust and the gas observations will help diagnose the origin of the concentric gaps. | Disks around high-mass stars | Disks and planet formation | 2019-01-15T00:00:00.000 |
| 2485 | 2013.1.00146.S | 20 | A Molecular ALMA Deep Field in the UDF | To date, our understanding of the molecular gas content in high-redshift galaxies is fundamentally limited by pre-selection of the galaxies at other wavelengths (optical/NIR/IR, sub-millimeter, radio). To overcome this, we propose an unbiased molecular deep field (CO spectral scan of band 3, covering all z>1) in the Hubble Ultra Deep Field. We will reach a molecular mass limit that is an order of magnitude deeper than previously possible, below the expected 'knee' of the CO luminosity function. We expect to detect >20 galaxies (both in line and continuum) and these detections will be compared to (1) our detailed SED modeling of all galaxies in the UDF (2) our analytic-empirical models that build on our current understanding of high-redshift molecular gas and (3) the latest adaptive moving mesh cosmological hydrodynamic simulations that include molecular gas. Stacking (both 2D and 3D) will push the statistical detection of sources to unprecedented depths. In summary, we will put unbiased observational constraints on the redshift-dependent CO luminosity function and meaningfully constrain the cosmic evolution of the universal molecular gas density for the first time. | Galaxy structure & evolution | Galaxy evolution | 2016-02-18T00:00:00.000 |
| 2486 | 2016.1.00754.S | 48 | Are mergers important for SMG evolution? | Luminous submillimetre galaxies (SMGs) identified in single-dish surveys have some of the most extreme star-formation rates in the Universe. During the epoch of peak star-formation (z~2) they contribute ~20% to the Universal star-formation rate density. However, despite nearly 20 years of intensive study the role of mergers in triggering SMG activity is still under debate, both observationally and theoretically. Recent ALMA continuum observations of single-dish selected SMGs have shown that up to 60% of these sources are blends of two or more component galaxies. However, the existing data are unable to determine whether these multiple components are physically associated (i.e. early stage mergers) or not. Different galaxy formation simulations have very different expectations with some predicting <5% of SMG blends are physical associations, and others that >~70% are. This program targets six single-dish SMGs, each comprised of two or more components, for which one has a robust spectroscopic redshift. We proposed to target CO for the remaining components to definitively determine whether the multiple components are physical associations, or simply chance line-of-sight projections. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-01-12T21:19:41.000 |
| 2487 | 2021.1.00658.T | 100 | Gamma-ray Burst Physics with ALMA: Direct Implications for the Explosions and Progenitors | Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, and thus serve as unique laboratories for high-energy astrophysics and compact-object formation, as well as premier probes of the high-redshift universe. Observations of GRB "afterglows" provide critical insight into the energy scale and local environment of the bursts, thereby elucidating the explosion mechanism and nature of the progenitors. However, the existing extensive optical/X-ray afterglow data alone are degenerate with respect to these GRB properties. Millimeter and centimeter observations are critical for breaking these degeneracies, but pre-ALMA GRB follow-up has yielded a mm-band detection rate of <5%. This is now being remedied with ALMA, with three well-sampled ALMA mm-band light curves published to date. Here, we propose to more than double the sample with a mm-band survey comprising ALMA ToO observations of 4 GRBs, and thus begin to address key unsolved questions in GRB physics. We will support these ALMA data with JVLA, ATCA, and GMRT observations, extensive optical follow-up (Gemini, Magellan, MMT, Keck), and X-ray monitoring (Swift, Chandra, XMM). | Gamma Ray Bursts (GRB) | Cosmology | 2023-05-28T14:49:08.000 |
| 2488 | 2023.1.00799.S | 0 | Peculiar Dust Grains in OMC 2/3 | It is assumed that dust opacities in molecular clouds follow a constant power-law profile with an index, beta. Recent studies of the OMC 2/3 complex, however, show a flattening in the spectral energy distribution at > 2 mm, implying a non-constant beta. The origin of this flattening is not yet known but amounts to elevated emission at ~ 3 mm by roughly a factor of two higher than expected from extrapolations of shorter wavelength (< 2 mm) data. This change in beta may be due to the intrinsic properties of the dust grains themselves or it could be due to contamination from other sources of emission. We will observe six dense cores in OMC 2/3 in Band 1 (~ 7 mm) and combine these data with continuum data from NOEMA and ALMA at 1.5-3.3 mm to measure their SED slopes at a longer wavelength. If the SED slope at > 3 mm changes (e.g., becomes negative), contamination is likely significant and must be corrected at 3 mm. If the SED slope is constant at > 3 mm, we would have strong evidence that the dust grains themselve produce the flatter profile. Such evidence would help us constrain dust models and helping us to convert thermal dust emission to mass in molecular clouds accurately. | Low-mass star formation | ISM and star formation | 2025-03-21T14:05:06.000 |
| 2489 | 2013.1.00211.S | 6 | X marks the spot: outflow-infall interaction in B335 | We propose to observe the central region of the isolated Class 0 prototar B335 with a 7-point mosaic in Band 6 with an angular resolution of 0.8", which corresponds to spatial scales of <100 AU at the source distance, to obtain detailed information on the physical and dynamical properties of the infalling circumstellar envelope and of the outflow-infall interaction. Our final goal is to highlight the interaction between the outflow and the accreting envelope close to the protostar, where outflows could actually reverse and end the infall of material, preventing further growth of the central protostar. This will give insights into the important role that the outflow-envelope interaction plays in the mass-assembling process and in determining the final mass of the forming star. Different outflow and high-density tracers (12CO, 13CO, C18O, H2CO, 13CS and CH3OH), together with the continuum, will be observed to probe different density and kinematic regimes, trace the morphology and kinematics of the outflows, the physical properties of the outflow cavity walls and the impact of the outflow on the envelope, and the distribution of the infalling gas and its interaction with the outflow. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-04-04T01:13:19.000 |
| 2490 | 2015.1.01195.S | 56 | Resolving the collision of supernova remnant N49 with a molecular cloud | LHA 120-N49 (N49) in the Large Magellanic Cloud (LMC) is the archetypical example of a supernova remnant (SNR) running into an interstellar molecular cloud. The shock manifests itself in X-rays, radio synchrotron radiation, optical and infrared fine structure lines and the heating and sputtering of dust grains, whilst the molecular cloud reveals itself by rotational emission from CO. Hence, N49 is one of the brightest SNRs in all of the Magellanic Clouds across the electromagnetic spectrum. Its position in the relatively unconfused Northern realms of the LMC lends it particularly well to a comprehensive and detailed study. One big obstacle to fully characterising the interaction is the absence of high angular and kinematic resolution images of the molecular emission. We propose to remedy this with ALMA maps of the CO and SiO emission at the collision interface at matching resolution to that of the extant multi-wavelength data. We will thus resolve the morphology, kinematics and excitation of the cloud collision and use - for the first time - SiO emission to trace the products of the sputtering of silicate grains and hence confirm the destructive nature of SNRs. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2017-03-24T14:30:34.000 |
| 2491 | 2013.1.00502.S | 2 | Anatomy of a Fried Egg | IRAS 17163 was recently identified by Lagadec et al (2011) as the closest and brightest Yellow Hypergiant. Infrared imaging of the dust emission implies a very intense mass-loss, with 2-4Msun of gas ejected in the last 500 years. This lead to the formation of at least three concentric dusty shells. Recent APEX data indicate the possible trigger of a bipolar outflow. This makes IRAS~17163 a unique object for the study of the mass-loss process ina spectacular short-lived phase towards the end of the life of a massive star, before it explodes as a supernova.We propose to resolve these shells in CO J=2-1 emission with ALMA, to probe the kinematics and morphology of the gas in this massive stellar envelope.This will enable us to measure the amount of gas ejected, the gas-to-dust mass ratio, the time scale of the ejection, and check whether or not a jet is being formed. These measurements are the key for understandingthe physics of the intense mass-loss during this short-lived, and thus rare, phase of stellar evolution. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-12-19T21:04:36.000 |
| 2492 | 2016.1.00450.S | 18 | An ISM Rosetta Stone for the Early Universe | The ALMA observations of the z=3.04 Herschel galaxy SDP 81 revealed a collapsing disk containing a galaxy-building starburst. However, the ALMA high-J CO observations were only sensitive to hot dense gas and also missed the more than third of molecular gas that is CO-dark. To obtain a full picture of the ISM in high-redshift galaxies, it is essential to observe lines that sample all phases of the ISM. In the redshift range 4 | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-09-28T13:24:24.000 |
| 2493 | 2015.1.00637.S | 41 | Are Planetary Orbits Aligned with Binary Orbits? | We propose ALMA observations of protoplanetary disks in 14 young binary systems, to test whether or not the two disks in a binary system are aligned with each other, and with the binary orbit. ALMA is currently the only way we can measure the three-dimensional orientation of the eventual orbits of planets in these systems; once the disks dissipate and the planets form, their orbits become invisible. The degree of misalignment between binary and planetary orbits has implications for planet migration and orbital evolution as well as for binary formation. In the process of making these measurements, we will test the validity of a previously-used method of measuring disk alignment, which recent ALMA observations have called into question. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2018-03-28T21:14:19.000 |
| 2494 | 2016.1.00842.S | 31 | Revealing the Radial Variation of Grain Growth in the Protoplanetary Disk around TW Hya | We propose to observe the protoplanetary disk around TW Hya in continuum emission at band 4 and 6 with 0.045" resolution using ALMA. Our previous ~3 au resolution observations at band 4 and 6 in ALMA cycle 3 DDT confirmed the existence of multiple gaps and rings found by Andrews et al. (2016), and we also found that the beta index of dust mass opacity is peaked at the most prominent gap at 22 au gap. However, the unoptimized antenna configuration during the observation period caused a serious problem for constraint of the radial variation of grain size distribution which can be estimated from beta. The proposed observations are to obtain better uv coverage at longer (>3000k-lambda) and shorter (<200 k-lambda) baselines, where our previous data are sparse. By combining the data with the previous one, the overall structure of the spectral index between band 4 and 6 will be confirmed, and then we will address the radial variation of dust growth, which might be related to the H2O snowline and/or radial transportation of growing dust grains incorporating sintering of volatile molecules. | Disks around low-mass stars | Disks and planet formation | 2024-07-27T00:00:00.000 |
| 2495 | 2016.1.00766.S | 63 | Linking high-mass star formation and SiO maser emission -- the Galactic centre dust-ridge cloud G0.38+0.04 | SiO masers are rarely detected towards star-forming regions (< 2.5%), and only in regions of known high-mass star formation. Thus far, only five SiO masers have been identified towards such regions in the Galaxy. Each of these is in some way unique, and so far no clear connection between them has been identified. In this proposal, we target a high-mass-star forming region (HMSFR) in the Galactic centre cloud G0.38+0.04. This is a high-luminosity (6.5x10^4 Lsun), young (pre-UCHII) HMSFR and is the richest site of rare maser emission yet known in the Galaxy. It is therefore an ideal source for advancing our understanding of SiO maser emission and its relation to HMSFRs. Our proposed ALMA observations have the unique capability of simultaneously detecting the dust, thermal SiO, and vibrationally excited SiO in the same observation, whilst achieving extremely high spatial (0.078") and spectral (~ 0.4 km/s) resolution. This will allow us to probe the dust continuum on the smallest achievable spatial scales, which will reveal any potential fragmentation and clustering and allow us to associate individual fragments with a corresponding maser detection. | High-mass star formation, Astrochemistry | ISM and star formation | 2019-01-08T21:39:32.000 |
| 2496 | 2022.1.00396.S | 29 | DEDI - Dust Evolution in Dense IRDCs | Measuring how dust opacity varies with environment in dense molecular clouds is important for understanding the physical processes that control dust evolution, including grain growth and ice mantle accretion. Such understanding is in turn important for having a secure dust opacity model for estimating cloud mass surface densities and thus masses. The ability to measure mass distributions in star-forming regions is of fundamental importance for the subject. We propose ALMA band 3, 4, and 6 continuum observations of a massive infrared dark cloud, expected to be representative of the initial conditions of massive star and star cluster formation, for which we have complementary estimates of dust opacity and mass surface density from infrared extinction studies including a novel new method using photometric and spectroscopic mid- to far-infrared extinction mappings. By comparing the ALMA inferred dust emissivity to the infrared inferred absorption opacities the team studied, we will obtain a unique understanding of the intrinsic biases of each method and thus more securely search for evidence of grain evolution as a function of environment in the dense infrared dark cloud. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2024-10-10T22:25:06.000 |
| 2497 | 2023.1.00787.S | 0 | Organic composition of externally FUV-irradiated protoplanetary disks: the unique case of d203-506 | Most stars are born in clusters that contain a few massive stars. These stars are prodigious sources of UV radiation. Despite its relevance to planet formation theories (our Solar System likely formed in a cluster environment) little is known about the role of external UV radiation during protoplanetary disk evolution. Compared to the widely studied isolated disks in nearby star-forming regions, externally photoevaporating disks likely have different planet-formation histories and chemical inventories. However, this has not been proven. We propose to spatially resolve, at 0.1'' resolution (40 au), the emission from the small organics C2H, CN, H2CO, and CH3OH toward the externally illuminated disk d203-506 in Orion. Recent ALMA and JWST observations reveal a very peculiar and rich carbon-chemistry (PAH, CI, CH+ and a new hydrocarbon ion) indeed pointing to a different organic chemistry than in isolated disks. Here we aim at unveiling the origin of the above molecules as well as to constrain the growth of carbon chemistry in externally irradiated disks; a phase experienced by most disks, including the proto-Solar System. | Disks around low-mass stars | Disks and planet formation | 2025-08-09T21:07:24.000 |
| 2498 | 2019.2.00155.S | 1105 | The home stretch: Completing the redshift catalogue of a large flux-limited high-redshift Herschel sample | We propose to measure with the ACA redshifts of 23 galaxies from the brightest (S500um > 80 mJy) sub-millimeter (submm) galaxies from the Herschel surveys, that will complete our catalogue of robust redshifts for 270 high-redshift Herschel sources, as measured by on-going projects using NOEMA and ALMA and previous ACA programs. These remaining sources are observed most efficiently with the ACA. A complete coverage of this 500um flux-limited sample of 270 bright submm galaxies with reliable spectroscopic redshifts is crucial to draw statistical conclusions, enabling us to determine the role of hyper-luminous (Lfir > 10^13 Lsun) galaxies in cosmic stellar mass assembly, increase the number of known lensed sources at the peak of cosmic evolution (z ~ 2.5), and identify other types of rare objects. Together with existing and ongoing ancillary data in the optical and near-infrared (SALT, NTT, VLT, Keck, Spitzer and HST), this comprehensive sample will provide the baseline for future detailed studies of the brightest galaxies at the peak of cosmic evolution, and will be unique until the next generation of (submm) space telescopes. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2021-04-14T04:28:42.000 |
| 2499 | 2016.1.00533.S | 22 | The Molecular Clould Population in NGC 5044 | NGC 5044 is the central dominant galaxy in the X-ray brightest group of galaxies in the sky and hosts a moderate cooling flow. Our 30min ALMA cycle 0 observation of NGC 5044 showed that the cooling flow in N5044 is a breeding ground for molecular gas and that significant amounts of gas must be precipitating out of the thermally unstable hot gas. Cooling flows have always been a study of star formation in an extreme environment. The NGC 5044 group is the best target for studying star formation in a cooling flow due to its proximity and extensive multi-frequency coverage. Our cycle 0 observation detected 24 molecular structures in NGC 5044. Due to the limited spatial resolution in cycle 0 data, the detected structures are probably giant molecular associations and not individual GMCs. For cycle 4, we propose to mosaic the central 5 by 5~kpc region in CO(2-1) with the 12m array. With the higher resolution available in cycle 4, these structures should be resolved into hundreds of GMCs. Our proposed cycle 4 observation will thus permit the first ever statistical study of a large population of molecular clouds that condensed out of thermally unstable gas in a cooling flow. | Galaxy groups and clusters | Cosmology | 2018-01-20T12:36:08.000 |
| 2500 | 2016.1.00637.S | 0 | eta Crucis campaign | Herschel observations of naked-eye star eta Crucis (HD 105211), in the Southern Cross, revealed a resolved debris disk likely generated by a ring of planetesimals at 155 AU. At a mere 19.8 pc away, eta Cru is one of the closest and brightest (V=4.1) debris-disk host stars. The debris ring is also extremely bright--0.5 Jy at 100 microns--and extended, with a major axis of >14 arcseconds. Here we request a 242 GHz (1.2 mm) map of eta Cru. Our goals are (a) to resolve the inner hole of the disk, (b) to use the integrated 242 GHz flux density to compute the mass and surface density in mm-sized grains, which may be raw ingredients for ongoing planet formation on 1-2 Gyr timescales, and (c) to use the radial extent of the disk to place limits on the mass of a possible planet orbiting near the inner edge. | Debris disks, Exo-planets | Disks and planet formation | 2019-05-24T17:05:10.000 |
| 2501 | 2015.1.00570.S | 2 | Anatomy of a jet-cloud interaction and starburst in Minkowski's Object | What happens when the relativistic jet from an AGN impacts a gas cloud? This question is difficult to answer observationally given the lack of well-studied examples, but is important given that it may have important implications for our understanding of feedback. Radio jet induced star formation was common in the early Universe, but only a handful of low redshift analogues are known. Among them, Minkowski's Object (z=0.02), with a clear jet-cloud interaction and starburst, stands out. Although extensively studied in the optical, UV and radio, only ALMA has the sensitivity to study the jet-cloud interaction in molecular gas. The aims of this proposal are: (1) to study the detailed distribution of molecular gas in relation to the HI cloud and the star formation region, (2) to study the detailed dynamics of the interaction on a smaller spatial scale than possible in HI, and compare to numerical simulations, (3) to search for evidence of feedback by the starburst on the interstellar medium in the form of an outflow of molecular gas, and (4) to estimate the total mass of molecular gas and investigate the extent to which this unusual object obeys the Schmidt-Kennicutt law. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2017-03-03T22:57:19.000 |
| 2502 | 2019.1.01540.S | 6 | Structure and kinematics of the innermost region of the circumnuclear torus in NCG1068 | We propose to image the inner part of the obscuring circumnuclear torus in the archetypal Seyfert galaxy NGC1068 at the highest band 7 resolution available with ALMA: 0.013"=0.9pc, probing CO(3-2) and HCO+(4-3) line emission and the 340 GHz continuum. In our cycle 6 project we have imaged these with a 6 times larger beam and detected compact high velocity CO(3-2) at the nucleus. Remarkably, while the CO velocities match those of the H2O masers, the CO is in apparent counterrotation with respect to the H2O. This indicates strong noncircular motions, which can reflect a fast outflow, or significant warping of the inner disk. With our proposed data we will well resolve the velocity field of the high-velocity gas in CO(3-2), thus distinguishing between kinematic models for the origin of this emission. We will also probe the spatial, kinematic and density structure of the torus, and will be able to tie this into even higher resolution MATISSE/VLT observations of the warm and hot dust in the innermost region of the torus. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-10-08T13:20:58.000 |
| 2503 | 2012.1.00640.S | 2 | Dust and Molecules at Low Metallicity | The assembly of star forming molecular clouds is poorly understood in low metallicity galaxies. These galaxies are typically forming stars, and thus must have molecular gas, yet they almost universally lack direct detections of CO. As a means to trace the molecular component of these systems, we propose to use ALMA to observe the dust continuum emission and the 230 GHz CO (J=2-1) emission line (3.05 hours) in the nearby low metallicity galaxy, Sextans A. Recent VLA HI spectral line observations of Sextans A have exceptional spectral resolution (1.3 km/s). This high velocity resolution allows us to reliably decompose the spectra into narrow and broad components which have been associated with the cold and warm neutral gas phases. Coincidence of dust and CO emission detected by ALMA with narrow HI spectra will both confirm the existence of a cold neutral medium as well as define the areas most conducive for molecular cloud formation. Combining the proposed ALMA observations with existing HST, VLA, SPITZER, and GALEX observations will allow us to separate local regions currently forming stars from those which have yet to form them. Understanding the local conditions which are most likely to form molecular clouds is extremely important to the general understanding of star formation, molecular cloud formation, and galaxy assembly/evolution. If our proposed observations confirm that the narrow HI emission is an effective tracer of the more elusive molecular component, then we will have calibrated a method which is generally applicable for all nearby low metallicity galaxies. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2015-07-30T14:39:59.000 |
| 2504 | 2015.1.01137.S | 45 | Difference of the Abundace of Cold Atomic Carbon between T Tauri and Herbig AeBe stars | We propose to observe protoplanetary disks around T Tauri and Herbig AeBe stars in the [CI] 3P1-3P0 line at 1" resolution. Atomic carbon is a unique probe for understanding disk dissipation and dust evolution in the disk, but a fine-structure line of atomic carbon at submillimeter wavelengths was not detected from a protoplanetary disk until very recently. However, we recently reported the first detection of [CI] emission from the protoplanetary disk around a low-mass T Tauri star with the Band8QM receiver mounted on the ASTE telescope. The next step to be taken is a survey of a representative sample of the disks to increase the number of detection. Our targets are nine well-studied disks in nearby star forming regions. If the [CI] emission is successfully detected from these targets, we will get clues for understanding the nature of atomic carbon in protoplanetary disks. These observations will provide us new information about the physical/chemical conditions in the upper layer of the disk. Our sample covers wide ranges of spectral type and age, and thus we will be able to discuss the connection between the [CI] emitting condition and the stellar properties. | Disks around low-mass stars | Disks and planet formation | 2017-06-07T10:07:34.000 |
| 2505 | 2019.1.01683.S | 40 | Shadows in time: resolving disk surface chemistry using inner disk shadows | Many chemical processes in the interstellar medium happen under conditions and on time-scales that cannot be easily probed with laboratory experiments here on Earth. However, protoplanetary disks can serve as excellent laboratories for astrochemistry as their geometry and physical conditions are well understood. In some protoplanetary disks, an inclined inner disk casts a shadow over half of the outer disk. This shadowing drastically changes the UV field in the surface layers of the disk. As disk material rotates into and out of this shadow on Keplerian orbits, we can use it to resolve the chemical evolution of material on 10-1000 yr timecales. This will allow us to infer reaction rates under astrophysical condtions. We propose to take this unique laboratory out for a spin to study the radical chemistry of CN and the ion-molecule chemistry of HCO+. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2023-05-09T00:00:00.000 |
| 2506 | 2019.1.00432.S | 6 | Test protocluster formation and evolution in Serpens South filament. | Many low mass stars form in clusters in filamentary clouds. Distribution of protostar separations is a powerful tool to probe the protocluster formation and evolution. Serpens South filament is found to show two sequential protocluster formation stages in neighboring sub-regions of the same filament: the northern part of the filament exhibits a scattered distribution of dispersing protostars, while the southern part is still actively making embedded protostars in a compact ridge. We propose high resolution (0.13" or 57AU) mappings of 1.3 mm continuum and the isotopic CO 2-1 lines to 37 spots in the filament that contain all 65 interesting protostars/mm cores to compare the small scale (57AU~500AU) multiplicity of protostars between the two parts of the filament (or two evolutionary stages). We will answer the key questions: 1) whether the 75~90AU short protostar-separation peak also appears in this filament; 2) whether the small scale protostar multiplicity is statistically homogeneous in adjacent sub-regions of this filament; 3) and whether it remains unchanged throughout the protocluster evolutionary stages. | Low-mass star formation | ISM and star formation | 2022-08-31T17:36:09.000 |
| 2507 | 2015.1.00939.S | 98 | CO Survey toward the Host Galaxies of Gamma-ray Bursts | Long-duration gamma-ray bursts (GRBs) are thought to be associated with the explosions of massive stars and are accordingly expected to reside in star-forming regions with molecular gas. There is ongoing debate as to whether GRBs occur in normal star-forming galaxies or under particular circumstances. Multi-wavelength observations of GRB host galaxies have been conducted, however, there is only a limited number of CO observations. We propose CO and dust continuum observations of 12 GRB hosts. This will be the first CO survey of GRB hosts and provide the largest sample with CO observations. Immediate objectives are (i) We derive molecular gas mass and star-formation efficiency, and compare them with other star-forming galaxies. (ii) We derive gas consumption timescale to see if the timescale is shorter than that of local star-forming galaxies as suggested by previous observations. (iii) We derive obscured star formation to understand whether GRBs trace star-formation rate or not. This project will double the sample with CO observations, or increase the sample with CO detections by a factor of five if we detect CO, which will significantly improve our understanding of GRB hosts. | Starburst galaxies, Gamma Ray Bursts (GRB) | Active galaxies | 2017-07-28T13:19:11.000 |
| 2508 | 2013.1.01166.S | 8 | Towards an evolutionary sequence of molecular gas in young debris disks: the hybrid disk candidate HD131835 | Most young stars harbor circumstellar disks which evolve from gas-dominated primordial disks to debris dust disks in about 10 Myr. In ALMA Cycle 0, our group discovered a disk around the 30-Myr-old HD21997 that links the primordial and the debris phases. The CO lines detected in HD21997 suggest large amounts of cold primordial gas, while the dust component is clearly secondary debris. In order to find more such "hybrid disks", we carried out a survey with APEX. Here we propose to obtain spatially resolved ALMA continuum and CO line observations of our most promising candidate, the debris disk around HD131835, where we detected CO with an intensity suggestive of a hybrid disk. From the observations we will (1) investigate the shielding and lifetime of CO molecules, (2) determine the co-location of the gas and dust components, and (3) decide if the gas is the remnant of the primordial disk, or secondary material produced from icy planetesimals. A primordial origin would suggest the existence of a whole new class of hybrid disks. The presence of primordial gas around >10 Myrs stars contradicts the current paradigm, and provides longer time for the formation of gas giant planets. | Debris disks | Disks and planet formation | 2015-11-24T12:42:05.000 |
| 2509 | 2015.1.01099.S | 1 | Imaging the circumstellar matter around the Class 0 protostellar binary SMM1/FIRS1 in Serpens | Binary and multiple systems represent a significant fraction of the total stellar population, however their formation is still poorly understood. Characteristics such as the orbital properties and mass ratios of binary systems are determined during their early development. These characteristics are predicted to be regulated by circumbinary disks by controlling mass accretion and releasing angular momentum from the system. How early circumbinary disks form largely defines the outcome of binary formation. Circumbinary disks have been observed in the case of L1551 NE, a Class I system that its components have accumulated more than 50% of their final mass. In this proposal we set to detect the circumbinary disk around the less developed Class 0 source SMM1 in Serpens, aiming to investigate the onset of binary formation and set evolutionary trends on the development of binary protostellar systems. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-10-21T09:46:58.000 |
| 2510 | 2013.1.01061.S | 0 | Examining the molecular coma of comet C/2012 K1 (PanSTARRS) | Cometary ices contain pristine material from the formation of the solar system, and studies of their composition provide unique information regarding the physical and chemical conditions of the early Solar Nebula. Use of gas-phase coma observations as probes of cometary ices requires a complete understanding of the gas-release mechanisms, but previous observations have been unable to ascertain the precise origin of fundamental coma species CO, H2CO, HCN, HNC and CS, and details regarding their possible formation in the coma are not well understood. We propose to obtain spectrally and spatially-resolved sub-mm emission maps of these molecules in the coma of comet C/2012 K1 (PanSTARRS), which will reach peak activity around perihelion in August 2014. The proposed 3D maps, including multiple spectral lines from CH3OH and the other species of interest, are required in order to determine the excitation, and therefore the precise distributions, of molecules in the coma. These measurements will provide quantitative tests of release models for the species of interest and will be vital in assisting the interpretation of our ALMA data on comets ISON and Lemmon (obtained in 2013). | Solar system - Comets | Solar system | 2015-08-05T22:31:02.000 |
| 2511 | 2019.1.01135.S | 170 | A Novel Exploration of Gas Content in Protoplanetary Disks | Observations of the Lupus star-forming region have revealed disks with low gas masses (<1 Jupiter mass) and gas-to-dust ratios (~1-10) based on CO isotopologue emission. This has implications for theories of planet formation because the disks are relatively young, only 1-3 Myr old. Alternatively, the disks could be CO-depleted resulting in underestimates of the total gas mass based on CO isotopologues. Current observations are insufficient for determining whether the disks are CO-depleted or not. We propose to use additional gas tracers, N2H+ and HCO+, in combination with the current CO isotopologue data and our thermo-chemical models to check for CO depletion. Our models reveal distinct trends in the relative line ratios of these three tracers for the CO-depleted vs. low gas-to-dust ratio cases. To test if these trends are realized, we select several disks from the Lupus region that span over an order of magnitude in gas-to-dust ratios derived from the dust mm emission and CO isotopologues. By probing for evidence of CO depletion, we will be able to determine if the disks have additional gas not well tracked by CO rotational lines. | Disks around low-mass stars | Disks and planet formation | 2021-02-15T05:29:41.000 |
| 2512 | 2018.1.00980.S | 4 | The First Unambiguous Detection of a Magnetic Field in a Protoplanetary Disk | We aim to detect linearly polarized 12CO (3-2) and 13CO (3-2) emission in TW Hya at a spatial resolution of 0.5" arising due to the Goldreich-Kylafis effect (GK). A detection of polarized molecular line emission will provide the first unambiguous confirmation of the presence of a magnetic field in a protoplanetary disk. Our sensitivities are based on known total intensities and observations of the GK effect in star forming regions which measure polarization fractions of between 3 and 8%. Our observations will allow us to detect polarization fractions down to 0.3% and 1.0% for 12CO and 13CO respectively. Our groups extensive background in thermo-chemical modelling, expertise in CO chemistry and polarization observations provides the perfect foundation for interpreting these unique observations. | Disks around low-mass stars | Disks and planet formation | 2021-07-02T17:44:07.000 |
| 2513 | 2023.1.00471.S | 0 | A Comprehensive Observational Test of Positive and Negative Black Hole Feedback | Our understanding of galaxy formation hinges on the feedback released from accreting supermassive black holes. Without it, theory over-predicts galaxy sizes and cosmic star formation history, making it critical to develop more realistic treatments of AGN feedback. To address this need, the Close AGN Reference Survey (CARS) has assembled a rich, hyperdimensional dataset for 33 nearby Type 1 AGN, anchored by VLT/MUSE IFU and HST FUV datacubes for each host galaxy, including archival ALMA CO observations for 14/24 CARS galaxies with significant molecular gas fractions. Here, we propose high-resolution ALMA CO(1-0) observations to survey the remaining 10 CARS galaxies with significant amounts of molecular gas. Uniting the proposed and archival ALMA observations with HST and MUSE will enable a statistically robust, high-resolution test of both negative and positive black hole feedback models. Specifically, we will 1) map the mass distribution and kinematics of the molecular component of AGN outflows; 2) probe how these outflows impact the cold molecular gas and star formation; and 3) evaluate whether the star formation efficiency is suppressed or enhanced by AGN outflows. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-06-06T16:54:44.000 |
| 2514 | 2015.1.00806.S | 18 | First ALMA observations of young circumplanetary disks | We propose ALMA Cycle 3 observations that will provide the first detailed look at circumplanetary disk material. We target two systems with young forming planets which are still embedded in the circumstellar disks of their Herbig Ae/Be hosts stars. Our group detected these objects in high-contrast imaging programs and previous observations of the circumstellar disk (with ALMA and in scattered light with NaCO) showed clear evidence for embedded objects. With ALMA we will probe the circumplanetary disk material by searching for higher levels of dust continuum and CO emission at the positions of known planets. These observations will allow us to make the first estimates of the mass and size of a circumplanetary disk. With the unprecedented sensitivity achieved by ALMA we will be able to detect circumplanetary disk masses down to 1.8M_Earth, and a circumplanetary disk-to-planet mass ratio down to 0.002. This is the first time that such an analysis can be carried out to constrain those parameters in planet formation theories, and therefore the results will open a new window to understand the physics of gas giant planet formation empirically. | Exo-planets | Disks and planet formation | 2017-03-06T10:47:30.000 |
| 2515 | 2015.1.00098.S | 259 | ALMA deep survey on GOODS-S-JVLA field | We propose deep 23 arcmin^2 imaging of GOODS-S to a depth of 0.06 mJy (1.1 mm, 1 sigma) thereby ensuring a uniform census of galaxies with SFR > 50 Mo/yr up to z~10. This panoramic deep survey will be sufficiently sensitive to locate and study, for the first time, over a hundred faint "sub-mJy sources" thought to dominate the extragalactic background. The proposed survey design follows the successful outcome of our earlier Cycle 1/2 surveys of SXDF (1.5 arcmin^2) and SSA22 (4.5 arcmin^2) to a depth of 0.055 - 0.066 mJy at 1.1 mm. In conjunction with the deepest JVLA 5cm data (0.3 uJy, 38 arcmin^2) along with the richest dataset of WFC3/IR-selected galaxies, we will determine the nature of the sub-mJy population. Through the redshift distribution, stellar masses, clustering, and AGN properties of this newly-found population, we will complete our understanding of the dust-obscured history of the Universe. Our proposed 23 arcmin^2 survey is the logical next step after the ongoing 4 arcmin^2 HUDF survey and will guide future wider area ALMA campaigns. Thus, the proposed survey will have strategic importance and enormous legacy value. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-02-01T21:20:49.000 |
| 2516 | 2016.1.01580.S | 34 | What drives the formation of super-Jeans cores? | Interstellar filaments represent a key stage towards the formation of stars. As they become gravitationally unstable, filaments fragment into cores, the direct progenitors of stars. The typical Jeans mass of such filaments is about a solar mass. This raises the question about the formation and support meachnism of super-Jeans cores, i.e. cores that are several time more massive than the Jeans mass. A local increase of the gas velocity dispersion (i.e. turbulence) is a commonly invoked physical mechanism to support such Super-Jeans cores against gravity and further fragmentation. We propose to use ALMA to observe apparently starless, super-Jeans cores of the SDC13 infrared dark cloud. We see local increases of the gas velocity dispersion for 20 out of the 32 detected cores. We aim to understand how these local peaks in velocity dispersion manifest, and what are the consequences on the formation of intermediate-/high-mass stars. | Outflows, jets and ionized winds, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-06-18T01:09:19.000 |
| 2517 | 2023.1.00387.S | 0 | Probing the transition from protoplanetary to debris disc in the Herbig AeBe star HD141569 | We propose to study with high resolution the circumstellar disc around the Herbig Ae/Be star HD141569. This disc currently sits in the middle of the poorly understood but very common transition from protoplanetary to debris disc, and its study offers a unique opportunity to understand how this rapid transition occurs and the dynamical processes that govern it. By characterizing the distribution of mm-sized dust we will determine if its multiple rings seen in scattered light observations are caused by the photoelectric instability (PeI) or planets at 10-200 au that carve gaps. Understanding the origin of the rings will also allow us to constrain the origin of its gas and dust, and thus determine if the disc material is protoplanetary or generated and resupplied by planetesimal collisions. In addition, its CO distribution and kinematics will allow us to constrain and test predictions of how the PeI or planets affect the distribution of gas in a low mass circumstellar disc. HD 141569 is the ideal target to study this transition phase. | Debris disks, Disks around high-mass stars | Disks and planet formation | 2025-07-17T20:09:52.000 |
| 2518 | 2013.1.00647.S | 7 | Gas Temperature Structure and Mass of the Disk around DM Tau | We propose high spatial resolution ALMA observations of CO emission lines from the transition disk around the source DM Tau. Our aim is to infer the temperature structure of the disk from a multi-line (6-5, 3-2 and 1-0 transitions), multi-isotopic ($^{12}$C$^{16}$O,$^{13}$C$^{16}$O and $^{12}$C$^{18}$O) study which traces gas at different spatial locations and hence physical conditions in the disk. The observational program will be accompanied by detailed thermochemical modeling that includes selective photodissociation of isotopic species to compute the gas temperature. Ancillary HD 1-0 line flux measurements will be used to constrain the gas mass of the disk. Comparisons between models and ALMA data will allow us to determine disk gas temperature structure, which is important in regulating the chemical state of the disk and forms a key input to various disk evolutionary processes such as viscous accretion, photoevaporation and finally planet formation. | Disks around low-mass stars | Disks and planet formation | 2016-09-09T05:25:29.000 |
| 2519 | 2013.1.00518.S | 9 | Constraining the Fragmentation Mechanism in the Class 0 proto-binary BHR71 | Binary star formation is a ubiquitous phenomenon in astrophysics and we aim to characterize the process of fragmentation during the earliest phase of the star formation process, the Class 0 phase. We propose to observe the wide (3200 AU; 16") Class 0 proto-binary system BHR71 in order to test predictions of the fragmentation theories with observations of the envelope structure and kinematics. The youth of this protostellar system indicates that it has not undergone significant dynamical evolution, thus we are viewing the near initial conditions of fragmentation. The kinematic structure will be observed at 1.7" (340 AU) resolution in C18O (J=2-1) at 1.3 mm; these data will be complemented by our existing ATCA and Parkes NH3 data on larger scales (> 2000 AU) with ~10" resolution. These data will enable us to map the kinematic structure on ~10000 AU scales down to ~340 AU. NH3 and C18O are complementary tracers in that NH3 is destroyed where C18O is present, mostly in the warm gas of the inner envelope. The spatial and kinematic structure of the dense gas and dust continuum will enable us determine if rotational fragmentation is likely or if another mechanism is at work. | Low-mass star formation | ISM and star formation | 2016-04-10T11:37:48.000 |
| 2520 | 2022.1.01714.S | 9 | The Cluster Formation and Evolution Cycle of a Nuclear Starburst: The Case of NGC 7552 | The complex interplay between nuclear starburst activity and the host galaxy ISM remains largely unconstrained at the relevant physical scale of individual star clusters. Here we propose to observe the circumnuclear ring of the luminous infrared galaxy (LIRG: LIR > 10^11 Lsun) NGC 7552, to measure the properties of 21 embedded star clusters discovered from previous Cycle 8 observations. As one of the only starburst LIRGs for which ALMA can resolve individual clusters, NGC 7552 represents a unique laboratory to study the earliest phases of massive cluster formation and evolution in an extreme environment. This proposal is a re-submission to obtain the missing intermediate-configuration Band 7 observations of CO (3-2) emission, which are necessary to estimate the total molecular gas mass within each cluster. The main question we will then address is: How do the derived cluster properties, and their inferred cluster formation efficiencies (CFE), change in the nuclear starburst environments of LIRGs? Understanding how the CFE changes between regions of different ISM densities, including extreme densities, is critical for understanding star formation and its evolution over cosmic time. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2023-10-12T23:32:43.000 |
| 2521 | 2022.1.01334.S | 32 | Unveiling the role of filamentary structures in star formation toward the mini-starburst region NGC6334 | The NGC6334 molecular complex is one of the nearest mini-starburst star formation regions, i.e., a miniature model of starburst galaxies. Using recent ACA band 3 observations of NGC6334, 25 filaments in the position-position-velocity space are revealed. These filaments show longitudinal velocity gradients, gas infall signatures, narrow-line SiO emission, and oscillating velocity and intensity. Unfortunately, the poor angular resolution (18"x10") and sensitivity (1sigma mass ~10Msun) prevents from studying filaments and embedded cores in detail. Therefore, we propose this follow-up ALMA program with a higher angular resolution (3") and sensitivity (1sigma mass ~0.13 Msun), in order to: 1) spatially and spectrally resolve filaments and embedded dense cores, 2) characterize the gas kinematics from ~1 pc filament scale down to ~0.02 pc core scale, and 3) examine the feasibility of using the SiO emission to trace the fossil record of the filament formation. This program will provide an unprecedented view of the global dynamical picture of the filament-based mini-starburst in NGC6334, which promises to unveil how the filament network promotes star formation in mini-starburst regions. | High-mass star formation | ISM and star formation | 2024-03-29T17:26:30.000 |
| 2522 | 2015.1.00042.S | 10 | Vibrational H2O emission in NGC 4418: a search for buried AGN through the greenhouse effect | An increasing number of galaxies are found to have extremely buried nuclei that are detected in vibrationally excited HCN emission/absorption at (sub)mm/cm wavelengths and in very high-lying rotational lines of H2O and OH in the far-IR. From accurate modeling of the current data, we propose a new observational tool, using the unique ALMA capabilities, to identify a definitive buried AGN signature in the most optically thick environments: detection of H2O emission within the nu_2=1 bending state at submm wavelengths. The selected target, NGC 4418, harbors the nucleus where the brightest HCN vibrational emission relative to the infrared luminosity, and the highest excitation in far-infrared H2O rotational absorption lines, have been found to date. | Galactic centres/nuclei, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2017-09-12T21:53:10.000 |
| 2523 | 2022.1.00506.S | 117 | Revealing the properties of low-luminosity AGN with ALMA and JWST | We here propose to charaterize the sub-mm emission from a sample of low-luminosty AGN (LLAGN) which will be observed with JWST, and determine how the emission mechanisms at these frequencies are linked, through (semi-)contemporaneous ALMA observations. The vast majority of AGN are low-luminosity, and as such understanding them is crucial to the AGN paradigm. These observations will allow us to study the physics of the central engine, by locating the transition frequency from optically-thick to optically-thin emission, which is expected to occur in the near-IR to sub-mm for jet-dominated cores but in at longer wavelengths if the core emission is dominated by the radiatively inefficient accretion flow. In addition, the high resolution of ALMA and JWST allows us to seperate galaxy and AGN emission, and create clean AGN templates and diagnostics that will be key in identifying LLAGN in upcoming deep surveys. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2024-07-14T10:30:13.000 |
| 2524 | 2019.1.00558.S | 35 | Photo-erosion of molecular clouds: The Horsehead | Feedback from massive stars plays a crucial role on the evolution of galaxies. Massive young stars can influence the evolution of molecular clouds by eroding and photo-evaporating their surfaces with strong UV-fields. Although these effects have been probed at the larger scales, the fundamental structure of molecular clouds at the smallest scales (< 0.1 pc) is poorly known. Only recently ALMA has revealed the spectacular substructure of cloud surfaces in the Orion Bar with 1'' (0.002 pc) resolution CO and HCO+ observations, revealing a fragmented ridge of high-density substructures and photo-ablative gas flows and instabilities. We propose to obtain a sensitive 50''x 50'' mosaic in CO 3-2 and HCO+ 4-3 at 0.5-0.8'' resolution (0.001-0.0016 pc), to resolve the fundamental structure of the gas at the edge of the iconic Horsehead nebula, a cloud that is moderately illuminated (G0~100 instead of G0~10^4 in the Orion Bar), and therefore more representative of the majority of UV-illuminated molecular gas in the Milky Way and normal galaxies. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2021-04-17T15:28:03.000 |
| 2525 | 2023.1.00286.S | 0 | Probing Ambipolar Diffusion in the Protostellar Envelope of HH211: Measuring Ion-Neutral Drift Velocity with ALMA | This project is to study the role of non-ideal magnetohydrodynamical effects, specifically ambipolar diffusion, in the star formation process. The magnetic diffusivity of ambipolar diffusion remains unconstrained observationally. Observations have suggested an increasing mass-to-flux ratio in the protostellar envelope from large to small scales in HH 211, which is a signature of efficient ambipolar diffusion. Therefore, we propose to observe the protostellar envelope in HH 211 with ALMA to measure the kinematics of the ionized gas traced by the H13CO+ (3-2) line and compare it with the neutral gas kinematics obtained from the archival C18O (2-1) data to determine the ion-neutral drift velocity. Combining this information with estimates of the magnetic field strength and curvature from the ALMA archival polarization data, we will be able to obtain the first observational estimate of the magnetic diffusivity of ambipolar diffusion. We have calculated the abundance profiles of CO and HCO+ with a chemical network based on the density and temperature profiles in HH211, and verified that both molecules can be used to trace the kinematics of neutral and ionized gas in similar volumes. | Low-mass star formation | ISM and star formation | 2025-07-26T04:48:05.000 |
| 2526 | 2022.1.00073.S | 80 | A joint ALMA and JWST public Legacy Field - Abell 2744 | We propose a deep (1sigma=60uJy) homogeneous Band 6 map of the most powerful known lensing cluster Abell 2744. Over >100 hours of ultradeep JWST imaging and spectroscopy (~29-30AB at 1-5um) are scheduled from 2022 over a highly magnified 4'x6' area, effectively doubling the area of the entire Hubble Frontier Fields and resulting in JWSTs deepest, and crucially, public observations. This program will fully cover the 4'x6' area, using continuous 30-GHz spectral scans to enlarge the survey volume to line emitters. We will 1) detect ~60 lensed ALMA continuum sources all with ultradeep JWST imaging + spectroscopy and a further ~25,000 lensed NIRCam sources at z=1-9 with ALMA coverage, 2) investigate the regulation of dust emission from JWST properties, 3) constrain the total(=UV+IR) cosmic SFR density at z=1-9, 4) determine the faint-end of the [CII]-SFR relation down to SFR~1 Msun/yr at z=6, and 5) search for [OIII]88um at z=11-13. To support a broad array of legacy science from the community beyond these immediate goals, we lift the 1-yr proprietary period and commit to releasing the reduced continuum maps and line cubes early 2023, in line with the JWST data releases. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-12-27T21:14:53.000 |
| 2527 | 2013.1.00858.S | 2 | Resolving the Chemical and Physical Structure of the Disk Forming Zone in L1527 | Physical and chemical processes associated with formation of a rotationally supported disk around the newly born protostar are important target for star formation studies. In this proposal, we resolve the transition zone between the infalling rotating envelope and the inner disk in the low-mass Class 0 protostellar core L1527 at a high angular resolution to study these processes. With our ALMA Cycle 0 observations, we recently discovered a drastic chemical change in the transition zone around the centrifugal barrier (100 AU in radius). Carbon-chain molecules and their geometrical isomers reside mainly in the infalling rotating envelope, while SO preferentially traces the transition zone. Such a phenomenon has not been predicted in any chemical models. It seems to be caused by the accretion shock in front of the centrifugal barrier. Confirmation of the accretion shock and detailed exploration of the shock structure at a high angular resolution is thus an important and urgent issue for understanding the disk formation. Moreover, this observation will put a stringent constraint on chemical evolution from protostellar cores to protoplanetary disks. | Low-mass star formation, Astrochemistry | ISM and star formation | 3000-01-01T00:00:00.000 |
| 2528 | 2013.1.00602.S | 7 | Probing molecular gas at high redshift through observations of hydrogen fluoride | We propose a study to test the feasibility of using hydrogen fluoride (HF) line observations with ALMA as a probe of molecular gas at high redshifts. Our proposal is motivated by recent Herschel observations revealing ubiquitous absorption by HF in the Milky Way and nearby (U)LIRGs. The Herschel observations corroborate theoretical predictions that HF is the dominant reservoir of interstellar fluorine under a wide range of conditions, and confirm that HF observations provide a unique probe of the kinematics of -and depletion within- material along the sight-line to bright continuum sources. We will perform a search for HF spectral line in three sources: the Cloverleaf quasar, in which a low sensitivity detection of HF has previously been obtained, and two high redshift galaxies strongly magnified by gravitational lensing discovered by Herschel: HATLAS J142413.9+022304 at z = 4.24 and HATLAS J114637.9-001132 at z = 3.26. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-07-31T05:13:40.000 |
| 2529 | 2018.1.00331.S | 110 | Does H2D+ probe the coldest and densest parts of molecular clumps? | Starless cores are the birth sites of stars; they are characterised by low-temperature and high densities. In these extreme conditions light deuterium-bearing molecules as H2D+ and D2H+ are thought to be the main unambiguous tracers of the gas. Despite their importance, these tracers have been observed only in very few sources, and recently an offset between H2D+ and highest densities traced by dust continuum emission peaks has also been reported. This may call into question the entire framework of H2D+ as an unambiguous mass tracer: one explanation for the offset is a temperature effect, the other is a chemical effect (HD depletion). Here we propose observations of H2D+ that, combined with our sophisticated three-dimensional magneto-hydrodynamical simulations, will shed light on this problem. We will test the universality of the depletion process and establish the role played by surface chemistry in the chemical evolution of starless cores. We will also provide estimates for the core age through the HD depletion process. | Astrochemistry | ISM and star formation | 2020-08-01T22:35:09.000 |
| 2530 | 2018.1.00707.S | 1 | Investigating the sunspot umbra and its millimeter brightening | Sunspots are the best-known and most prominent features on the solar surface. However, they are surprisingly poorly understood, with many models of sunspot atmospheric structure that diverge strongly in the chromosphere. An important reason for this divergence is that the atomic spectral lines on which the models are based generally sample only the hotter part of the gas. ALMA will close this gap in our knowledge, since it provides diagnostics of both, the hot and cool gas in the sunspot chromospheres, with a sufficiently high spatial resolution to resolve and study the internal structure of sunspots. We propose to observe a sunspot umbra and its time variation in ALMA bands 3 and 6 to explain umbral millimeter brightening, the marked increase in 3mm brightness temperature, which we discovered in the ALMA SV data. A time sequence of ALMA images in the two bands will allow diagnosing the umbral thermal structure over a range of heights in the chromosphere. This will enable us to identify the most appropriate sunspot models, and to distinguish if the millimeter umbral brightening is due to shocked downflowing gas (coronal plumes), or to non-linear oscillations (umbral flashes). | The Sun | Sun | 2020-08-28T20:25:12.000 |
| 2531 | 2017.1.01219.S | 586 | Hunting for redshifts of faint DSFGs in A2744 | We propose an ALMA linescan for 7 secure DSFGs detected in our 1.1 mm cycle 2 ALMA images of Frontier Field cluster A2744. These modestly lensed (u~1.5-4) DSFGs likely lie at z~1-4 and span intrinsic luminosities of log[L(IR)]~11.5-12.3, thus probing a region of phase space that is currently poorly sampled at high redshift. However, their extremely red NIR colors and magnitudes make spectroscopic redshift detection impossible with current instrumentation. These ALMA observations will circumvent the current bottleneck to secure redshifts for all of the targets, allowing firm individual constraints (e.g., SFRs; stellar, dust and molecular masses via SED modeling; excitation ladders; gas depletion times) as well as to characterize and compare the population to previously studied brighter DSFGs and MS galaxies. The requested pointings will also serve to confirm and similarly constrain lower significance sources, detect new fainter line and continuum sources, place useful individual and stacking limits on many field galaxies (a substantial fraction with firm VIMOS, MUSE, and KMOS redshifts). | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-07-05T17:45:49.000 |
| 2532 | 2019.1.01166.T | 76 | Revealing the Diversity of Jets and Outflows in Tidal Disruption Events with ALMA | Transient accretion onto a supermassive black hole (SMBH) through the tidal disruption of a stray star offers a unique opportunity to study the birth and evolution of relativistic jets and to probe the environment around previously dormant SMBHs on sub-parsec scales. In the past few years we have shown that some tidal disruption events (TDEs) launch relativistic jets and broad outflows that generate synchrotron emission peaking in the mm on timescales of days to weeks. Our Cycle 6 program discovered the faintest TDE outflow seen to date, >10^6 times less luminous than the brightest known TDE jet. To understand this diversity and determine the origin of the faintest outflows requires: (i) a larger sample of TDEs from a diverse range of selection methods, and (ii) deep mm follow-up, only possible with ALMA. Here, we propose to observe up to 4 new TDE candidates with triggers from gamma-ray, X-ray, or optical surveys (Swift, Fermi, XMM-Newton Slew Survey, Pan-STARRS, CRTS, DES, ASAS-SN, ZTF). Our mm observations will be sensitive to both non-relativistic outflows and relativistic jets and will constrain jet formation models and rate predictions, which are currently highly uncertain. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2021-02-22T18:21:01.000 |
| 2533 | 2013.1.00073.S | 12 | A Search for Molecular Gas in the Circumnuclear Disk of M87 | We propose to search for CO(J=2-1) line emission from the circumnuclear disk of M87 to test theoretical models of accretion flow to supermassive black holes. Optical emission lines from atomic gas in this disk have been observed with HST. The model of Tan & Blackman (2005) predicts that this disk, accreting at the Bondi rate from the surrounding hot, X-ray emitting gas, should be gravitationally unstable and thus form stars via molecular clouds. Such a model may help explain why the system is underluminous compared to standard thin accretion disk models. A search for CO(J=2-1) emission with the SMA (Tan et al. 2008) has placed upper limits on the molecular gas content of the disk of ~8x10^6 Msun. In fact, weak (up to ~4 sigma) emission features were seen in the spectrum at the expected velocity, which, if interpreted as CO(2-1) emission, imply a gas mass of ~5x10^6 Msun. The proposed ALMA observations will achieve a factor of ~10 increase in sensitivity compared to the SMA observations. If the SMA-observed emission features are real, then ALMA will make a definitive detection, which would have important implications for our understanding of supermassive black hole accretion. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2016-12-09T21:29:50.000 |
| 2534 | 2018.1.00337.S | 12 | Low Metallicity Molecular Gas In the Dwarf Galaxy WLM | We propose to map the local group dwarf Irregular galaxy WLM in 12CO(2-1) and 13CO(2-1) to study the properties of molecular gas and star formation at low metallicity. CO discovered with APEX and Cycle1 ALMA maps revealed 10 tiny and dense CO clouds in two small regions. Here, we request to map a larger region of the Galaxy to determine: 1) the relationships between CO, dark molecules, and star formation (SF); 2) the galaxy-wide properties of CO clouds including the size-linewidth and virial mass-L_CO relations, and variations in these properties with SFR and position throughout the galaxy, and 3) the SFR per unit dark H2 molecule and CO molecule for comparison with analogous rates in other galaxies to understand the physical conditions necessary for star formation and the SFR in low-metallicity dwarfs. A key question is whether SF follows primarily CO and not just H2. The large-scale perspective given by these observations will provide a new understanding of SF processes at low metallicities. | Dwarf/metal-poor galaxies | Local Universe | 2020-02-16T02:55:09.000 |
| 2535 | 2013.1.00149.S | 10 | Rosette Globulettes | The total number of unbound low-mass free-floating planetary-mass objects in interstellar space in the Milky Way could several hundred billions. Gahm et~al. (2007) proposed that globulettes could be one source seeding the Milky Way with these low mass objects. Globulettes are extremely small (average size 2.5~kAU), round, and cold molecular clumps of planetary to brown dwarf mass that are silhouetted as dark spots against the background of nebular emission in expanding H II regions surrounding massive star-forming regions. We have studied the Rosette Nebula globulettes using NIR imaging and (sub)mm molecular line observations. The strong CO emission observed in the globulettes encourages us to continue the studies using ALMA. We want to observe two small size globulettes in CO 3--2 and 2--1 transitions (and isotopologues). The data will be analyzed using 3D non-LTE radiation transfer program and with an advanced astrochemical {\sc 3d-pdr} code. We will be able to produce unprecedentedly seen synthetic observations which will be compared with the observational data thus offering a deeper understanding of the physical and chemical properties of globulettes. | Inter-Stellar Medium (ISM)/Molecular clouds, HII regions | ISM and star formation | 2016-08-07T11:05:20.000 |
| 2536 | 2022.1.01439.S | 77 | Pre-processing of galaxies in the infalling groups to the Virgo Cluster | A significant fraction (40%) of cluster populations is accreted through the groups, and the group environment affects member galaxies, making them red and passive before they fall into a cluster. This pre-processing can produce the quenched galaxies at the outskirts of the cluster. Thus, it is important to study the impacts of pre-processing on group members to understand galaxy evolution in a hierarchical universe. In particular, probing the molecular gas properties is a key to understanding the quenching of star formation in the group environment. Therefore, we propose to obtain 12CO (1-0) imaging data of 30 galaxies of the NGC 4636 and NGC 4261 groups, using the Atacama Compact Array (ACA). These two groups falling into the Virgo cluster, which shows that some group members have low star formation rates and low HI gas fractions, are ideal laboratories to probe the pre-processing. By combining the ACA CO data with multi-wavelength data (HI, optical, UV, and X-ray), we will investigate how significantly the pre-processing affects 1) CO structures in both distribution and kinematics and 2) star formation processes of group members. | Galaxy groups and clusters | Cosmology | 2024-04-24T10:35:33.000 |
| 2537 | 2023.1.00843.S | 0 | Disentangling the ionization structure of HII regions in a density-bounded Lya emitter in the Reionization Era | We propose ALMA [OIII] 88um and [CII] 158um imaging of a z = 6.105 LAE, RXCJ2248-ID3, which was also targeted with Cycle-1 JWST NIRSpec-IFU. This LAE is a typical representative of galaxies in the EoR in terms of UV luminosity and is the most robust candidate for a 'matter-bounded' galaxy, where ~70% of LyC photons can escape outside the HII regions. By combining the UV-to-optical spectral lines (13 detections and 6 upper limits) obtained with JWST and ground-based facilities, our Cycle 10 ALMA imaging of [OIII]88 will precisely determine the physical properties of ionized gas, which enables us to understand the evolutionary stage of HII regions in RXCJ2248-ID3 for the first time. In addition, our sensitive [CII] search will reveal neutral ISM as the birth could of stars on one hand. On the other hand, for a matter-bounded geometry, little amount of neutral ISM must be associated with the HII regions, counterpredicting the presence of neutral ISM. Therefore, this test case will serve as a benchmark for understanding the geometry and ionization structure of multi-phase ISM, providing the key knowledge on the objects contributing to cosmic reionization. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2025-06-01T01:59:51.000 |
| 2538 | 2016.1.00035.S | 103 | Nuclear spin ratios as clues to the origin of deuterated ammonia | Ammonia and its deuterated variants are among the very few tracers of the physical and chemical conditions inside prestellar cores where stars and planets form. To fully exploit observations of these species, one should understand their formation. With this aim we wish to determine the spatial distributions of the ortho/para ratios of NH2D and NHD2 in the starless core Ophiuchus/H-MM1. NH2D and NHD2 are supposed to form primarily in the gas phase, in reactions which should lead to clear deviations from the statistical ortho/para ratios (3:1 and 2:1). Previous (single-dish) observations are, however, consistent with statistical spin ratios, which are characteristic of grain-surface production. Because of a lack of spatial information, one cannot exclude the possibility that the ratios deviate from statistical values in core centres where gas-phase reactions most likely dominate. The proposed mapping with ALMA+ACA aims at resolving this issue. Different spin ratios in the inner and outer parts of the cloud would imply different formation mechanisms in these regions, whereas similar spin ratios everywhere would indicate that the current gas-phase reaction scheme needs to be revised. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2018-03-25T09:04:54.000 |
| 2539 | 2024.1.01045.S | 0 | A Multi-frequency Study of Blazars at Cosmic Dawn | Relativistic jets are thought to play a key role in the formation and co-evolution of massive galaxies and black holes at all cosmic epochs. Blazars are bright radio sources whose jets are pointed towards the observer, and can rapidly vary: the study of such sources at cosmic dawn can critically inform us about the interplay of powerful jets and galaxies in the very early universe. However, current observations do not allow for a meaningful analysis. Here we propose a joint ALMA+VLA proposal to study the host galaxies and radio jets of two extreme blazars at z=5 and at z=7 (the highest-z blazar known so far). We aim to robustly constrain both the dust emission from their host galaxies and the synchrotron emission from the jets via a combined fit of their 1-400 GHz spectral energy distributions. Joint, quasi-simultaneous observations over the radio and (sub)-mm range are essentials to minimize the effect of the strong variability observed in these sources. We will assess any feedback effect of the jets onto the host galaxies, while constraining the jets lifetimes. This program will allow for the first systematic study of extreme blazars in the first billion years of cosmic history. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-11-20T10:55:37.000 |
| 2540 | 2016.1.00714.S | 230 | Chameleon's Dark Neutral Matter | Analysis of gamma ray emission from local molecular clouds has found an excess of matter over the gas traced by HI and CO emission - the Dark Neutral Matter (DNM) -- with a mass comparable to that of the molecular gas seen in CO. The most likely explanation for DNM is diffuse H2 whose CO abundance is too low to produce significant emission but optically thick, cold H I has also been suggested. We propose to investigate the properties of DNM in Chameleon by searching for molecular absorption against a flux and sensitivity limited sample of 13 background QSOs with DNM column densities ranging up to 4x10^20cm-2. We will use lines of HCO+ and CCH to trace diffuse H2 down to column densities N(H2) ~ 10^19 cm-2, enabling us to detect any H2 associated with the DNM. Chameleon is well suited because it has been extensively studied in H I, CO, optical extinction, dust and gamma rays, is nearby (150 pc) and at high galactic latitude, hence the absorption lines will be unambiguously associated with it. The number of sources will allow us to test the association of DNM with H2 and put better constraints on the DNM mass. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-03-23T20:29:47.000 |
| 2541 | 2019.1.00876.S | 24 | How do stellar bars alter the properties of the molecular gas disk | Analysis of the first 120pc resolution CO(2-1) maps from our PHANGS-ALMA LP reveals a tight relation between molecular gas surface density and line width, implying that molecular gas is close to energy balance across star-forming galaxy disks. Central regions in barred galaxies deviate markedly from the relation suggesting that bars significantly alter molecular gas properties. We propose 0.25" (20pc) high-resolution follow-up observations for 6 carefully selected, barred, CO-bright galaxies with large line widths, covering a diverse set of morphologies/bar properties. The sample size ensures robustness against effects of (fast) time evolution. The proposed data will test four physical mechanisms to explain these surprising results: (a) intra-cloud motion (b) stellar feedback from nuclear star formation (c) large-scale shocks induced by the bar (d) coupling of internal cloud kinematics to orbital motions Understanding which physical mechanism(s) cause the centers to behave differently is key to link molecular gas structure and physics to star formation (from PHANGS-HST) in this unique environment, providing a key link to modelling and observations of the CMZ in our own galaxy. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2022-04-26T10:43:04.000 |
| 2542 | 2018.A.00052.S | 60 | Is Sagittarius A* in a New State? | Sagittarius A*, the variable radio/IR/X-ray source associated with the supermassive black hole at the center of the Galaxy, has recently (April-May 2019) displayed unusual episodes of activity in the infrared and at 230 GHz. An unprecedentedly bright intensity excursion was observed at 2.2 µm with the Keck Observatory, well outside of the range of the 13,000 previous independent integrations with Keck, VLT and Spitzer. Other Keck observations in April and May have also shown episodes of unusually high fluxes, leading us to consider whether the source has entered a new, higher state of activity, or whether its accretion rate has risen. In either case, it is important to learn whether it is evolving and how long it will last, presuming that it is lasting longer than the April-May time frame. We therefore propose to observe SgrA* with ALMA at 345 GHz -- the peak of the SgrA* SED -- on 4 occasions separated by a month between July 21 and October 19. The first of these would be of considerably enhanced scientific value because it would correspond with simultaneous observations by Chandra, Spitzer, and NuStar. | Galactic centres/nuclei | Active galaxies | 2020-02-29T20:14:09.000 |
| 2543 | 2011.0.00020.S | 0 | Molecular line flux ratios and AGN feedback in gas/dust-rich galaxies | We propose multiple submillimeter molecular line observations of well-calibrated nearby gas/dust-rich infrared luminous galaxy nuclei dominated by AGN (a mass-accreting supermassive blackhole) and starburst activity. Our scientific goal is to establish a solid method to differentiate the effects/feedback from elusive AGNs and starbursts deeply buried in gas/dust, based on the flux ratios of submillimeter molecular emission lines which probe the same gas phase in galaxies. Our targets are nuclear emission dominated and the relative energetic contributions from AGNs and starbursts have been quantitatively and consistently derived, thus serving as an excellent laboratory to understand the physics behind the observed molecular line flux ratios. Our proposal best matches to the ALMA cycle 0, because (1) we need line flux ratios (i.e., spectroscopy) of compact sources, and (2) the ALMA 16 x 12m antennae first enable us to observe multiple sources at multiple submillimeter molecular lines within several hours (1/500 required exposure time, compared to SMA). In the future ALMA full operation era, our rest-frame submillimeter energy diagnostic method can be applied to the distant universe (z > 1), where gas/dust-rich infrared luminous galaxies are known to dominate the cosmic energy budget, and so has a huge potential to understand the history of star-formation and supermassive blackhole mass growth in the early universe. Our observational result can also contribute to the public promotion of ALMA, by demonstrating the power of ALMA submillimeter observations to prove deeply buried active supermassive blackholes (which are interesting objects to non-astronomers, but cannot be studied in the most popular optical wavelength). | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2014-01-16T08:11:00.000 |
| 2544 | 2016.1.00415.S | 0 | Where does the Faraday rotation in M87 come from? | Our team has recently reported the first ALMA polarization measurement of Faraday rotation at submm wavelengths from the base of an AGN jet. We have found strong evidence of a very high magnetic field, possibly close to the Eddington magnetic limit. A similar scenario could be taking place at the jet base of the AGN in M87, where another group detected hints of high Faraday rotation from SMA observations at 1\,mm. These authors interpret the Faraday rotation in a different way, as due to a plasma screen related to inflowing material, and conclude that the accretion rate in M87 must be extremely low. We propose multi-frequency (bands 3 and 6) observations of M87, to definitely answer the question about the true origin of the Faraday rotation in M87 (either related to the jet or to the infalling material). This study is crucial for a better understanding of the accretion and jet-launching mechanisms in M87, which is one of the closest AGN to the Earth. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-02-16T09:59:47.000 |
| 2545 | 2016.1.00263.S | 44 | Dissecting the clumpy structure of the SF powered massive molecular outflow of ESO320-G030 | Using our ALMA CO(2-1) high-resolution (60 pc; 0.25") data, we detected a fast (~450 km/s) massive (1e7 Msun) molecular outflow in the SF-dominated LIRG ESO320-G030. We resolved this 2.5 kpc molecular outflow into multiple clumps of molecular gas with sizes about 100-200 pc. The sub-kpc excitation and physical properties of massive molecular outflows are poorly known, despite they are crucial to confront theoretical models with observations, so the outflow of ESO320-G030 offers a perfect opportunity to remedy this. For the first time, we aim at obtaining spatially-resolved measurements of several CO transitions (1-0, 2-1, 4-3 and 6-5) for the outflowing molecular clumps. Using radiative transfer models, we will derive the physical properties (excitation, density, mass, and CO-to-H2 conversion factor) of the individual clumps. This analysis will serve to establish the time evolution (cooling, heating, evaporation, formation) of the molecular gas in the outflow and determine if the physical conditions in the clumps favor star-formation. All these results will provide strong constrains for numerical simulations of the structure and evolution of molecular outflows. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-02-09T22:59:15.000 |
| 2546 | 2013.1.00071.S | 8 | Resolving the atomic gas accretion flow surrounding the SgrA* | The Galactic center uniquely provides the opportunities to resolve how the supermassive black hole accrete in inner than 5 pc scale. Our previous GBT-100m and SMA observations of molecular lines have resolved that the well-known 2-4 pc Galactic circumnuclear disk (CND) may be the convergence of several >2 pc scale molecular gas streams. The ionized mini-spiral arms in the inner ~1 pc radius further indicated that part of the molecular gas streams may penetrate inside the CND. However, the previous 22" resolution OI line observations suggested that the ionized mini-spiral arms may be merely the ionized rim of the ~10 times more massive atomic gas streams. In this proposal, we want to take the advantage of the new CI observation capability of ALMA Band8, to resolve these atomic gas streams at a subarcsecond resolution. The aim of this proposal is to unveil detailed morphology and kinematics of the atomic accretion flows for the first time, and will diagnose from both spatial distribution and the observed velocity, how the atomic gas survive the ionizing flux when approaching the central OB cluster and the black hole. | Galactic centres/nuclei | Active galaxies | 2017-06-29T04:14:34.000 |
| 2547 | 2018.1.01131.S | 262 | A molecular line survey of FU Ori Outflows | YSOs that are undergoing rapid accretion episodes,i.e. FU Ori objects (FUors), display strong outflow activity. These outflows release large amounts of energy, thereby dispersing the infalling envelope that feeds the disk. X-ray emission can be produced during FUor eruptions and is known to be a critical ionizing source in disks, playing an important role in disk dispersal. However, the potential for high-energy-induced molecular ionization and chemistry at earlier (protostellar) evolutionary stages, and the importance of such radiative processes relative to outflows (shocks), is unexplored. We propose ALMA band 6 observations of HCO+, CO, HCN (and isotopologues), and molecular shock tracers to characterize the outflow/disk system energetics and molecular ionization of FUor object environments. Our sample for this pilot study comprises four of the best studied FUor and FUor-like YSOs, all of which have well-characterized X-ray emission properties. By combining the ALMA 12 m and ACA arrays and using their multi-scale mapping capabilities (resolution between 0.2'' and 30''), we will thoroughly investigate the chemical and physical structures and kinematics of the sample objects. | Outflows, jets and ionized winds | ISM and star formation | 2020-03-17T21:07:17.000 |
| 2548 | 2022.1.01355.S | 14 | An Arc and a DOG at z=2.7: A Story of Two Extreme Galaxies | We propose ALMA Band 3+4 observations of an extreme system at z=2.7. The system includes a strongly lensed (mu=12) galaxy (the ''8 o'clock arc'') and a hot, dust-obscured galaxy (Hot DOG). The 8 o'clock arc is one of the most intrinsically UV-luminous and massive galaxies known. The Hot DOG has a tentative redshift of 2.7, is extremely compact (unresolved in HST imaging), and has a spectral energy distribution similar to - but redder than - other dusty QSOs and hot DOGs. The two objects are likely interacting (they are separated by 5 arcsec). With a single ALMA pointing we can target both the 8 o'clock arc and the Hot DOG. We will target the CO(5-4) and CO(3-2) emission in both. For the 8 o'clock arc we will then measure gas dynamics, test for rotation/merger indications, measure the total mass and M(gas)/L(CO) ratio, and measure the gas density and kinetic temperature of spatially resolved star-formation. For the Hot DOG we will measure its redshift and determine its nature, study gas dynamics, and search for gas outflows. We will test predictions for massive galaxy formation in this potentially unique, extreme, interacting system for the first time at z~3. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-10-02T16:32:05.000 |
| 2549 | 2011.0.00136.S | 0 | Sulfur and water mapping in the mesosphere of Venus | We propose to map sulfur and water in the mesosphere of Venus, using the SO2 transitions at 336.089 GHz and 346.652 GHz, the SO transition at 346.528 GHz and the HDO transition at 335.395 GHz in order to study the latitudinal and day/night variations of these species. In addition we will observe the CO (3-2) line at 345.795 GHz which will constrain both the thermal profile and the CO vertical distribution and will be used for wind mapping. | Solar system - Planetary atmospheres | Solar system | 2014-03-19T14:07:14.000 |
| 2550 | 2019.1.01131.S | 5 | Thermal Emission from the Uranian Rings | Recent ALMA Cycle 5 observations by our team detected thermal emission from the Uranian ring system for the first time, providing new constraints on the thermal inertia, rotation rate, and filling factor of the epsilon (brightest) ring. We propose to obtain flux measurements for the other eight inner main rings and map the ring system at a resolution 10x greater than the Cycle 5 observations and comparable to Keck AO observations, determining the proportion of millimeter-sized grains in the inner rings. Combining our measurements with in-hand and proposed thermal infrared observations, we will determine the filling factor and constrain the thermal inertia, rotation rate, and emissivity of all of the inner rings individually. Comparing these measurements between rings will shed light on the dynamics at play in this unique ring system and hint at whether all the rings were sourced from the same parent material. We can also detect thermal emission from seven of the 13 small inner moons of Uranus, constraining their rotation rate and emissivity as well. The observations will also search for atmospheric features too small to be seen by the Cycle 5 data as a secondary objective. | Solar system - Planetary atmospheres, Solar system - Asteroids | Solar system | 2022-11-09T21:09:02.000 |
| 2551 | 2019.2.00124.S | 40 | An ACA CO survey: Identifying the best candidates for (approximately less than 2% precision) Black Hole mass measurements | It is now well established that nearly all galaxies have a supermassive central black hole (SMBH) whose mass scales with host galaxy properties, but we are still short of understanding the underlying physics. Our interpretations of black hole mass and black hole (and AGN) evolution at all redshifts are effectively based on the M-$\sigma$ relation, but we are at the limits of few hundred data points with substantial measurement uncertainties and systematics. Additional high-precision data, and a better understanding of the systematics between different methods, is required to find the connection between galaxies and their SMBHs. ALMA is potentially capable of measuring several hundred SMBH masses, but the measurement technique requires validation. We propose ACA imaging of CO J:3-2 and continuum in a sample of 28 galaxies whose SMBH sphere of influence is >=0.16arcsec. Our primary goal is to (a) identify all candidates for future high precision measurements of CO-based SMBH mass and (b) constrain the galaxy potential with kpc-scale gas dynamics. This will allow validation of CO-based (and alternative) SMBH estimates made at lower resolution. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2022-08-30T18:33:23.000 |
| 2552 | 2013.1.00525.S | 7 | Caught in a Cosmic Tango: ALMA Spies the Interplay Between Dual AGN in Merger Remnant Galaxies | Major galaxy mergers are particularly important for galaxy evolution as they can funnel fuel (gas) into the center of the galaxy triggering both star formation and an active galactic nuclei (AGN). Thus, as a natural consequence, systems with 2+ accreting supermassive black holes (SMBHs) `caught in the act' of merging represent a critical stage in the evolution of a galaxy. Only a few, 13, such dual AGN are known. The properties of the gas in these systems will offer critical clues to the external and internal conditions under which both SMBHs can be activated during these encounters and their influence on the host galaxies. We propose an ALMA study aimed at attaining new understanding of SMBH and host galaxy growth at a critical stage in the merger process: near coalescence. Specifically, we will map at high spatial resolution, ~100 pc, the molecular gas distribution and its kinematics in all 4 merging galaxies for which this is possible given the current ALMA capabilities. These observations will prove instrumental in determining the conditions which are conducive to simultaneous growth of both SMBHs as well as its effect on the host galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2016-12-16T20:52:22.000 |
| 2553 | 2021.1.00059.S | 31 | A Top-down View of Massive Cluster Formation in a Nearby Nuclear Starburst Ring | We aim to understand the formation and evolution of young massive clusters (YMCs) with high-resolution observations of a relatively face-on nuclear starburst ring in the nearby galaxy M95 (NGC 3351). We will use ALMA to observe extinction-free tracers of dust, dense molecular gas, and recent star formation at 0.12" = 6 pc scales, which is adequate to discern and conclusively identify YMC progenitors. These observations represent the last missing element in the multiwavelength inventory (including VLA, VLT/MUSE, HST, and JWST) and will enable us to: (1) identify forming YMCs at the earliest, heavily embedded stage, (2) characterize the ongoing star formation and stellar feedback processes inside YMCs, and (3) put YMC formation in the context of their natal galactic environment. This will be just the fourth embedded YMC population study conducted with ALMA, and more crucially, the first in a nearly face-on system. The top-down viewing angle will allow us to establish a quantitative link between YMCs and their surrounding ISM and dynamical environment through multiwavelength synergies, thereby providing unique observational tests for massive cluster formation theories and simulations. | High-mass star formation, HII regions | ISM and star formation | 2022-10-13T18:09:54.000 |
| 2554 | 2023.1.00180.L | 0 | The COSMOS High-z ALMA-MIRI Population Survey (CHAMPS): A Wide-Area Comprehensive Survey of the Dusty Universe | To trace the evolution of galaxies through cosmic time, a multi-band survey including sub-mm data is crucial, especially since recent small-area blank-field surveys show a considerable number of dust-obscured sources even into the Epoch of Reionization at z=6. We propose to carry out a 0.18deg2 blank-field survey at 1.1mm in the COSMOS field, CHAMPS, 3x the area of existing ALMA surveys, to push our understanding of the dusty Universe. CHAMPS complements deep, high-resolution MIRI and NIRCam observations from two JWST Cycle 1 programs with essential sub-mm observations. This will enable us to construct UV-FIR multiwavelength SEDs of ~30,000 MIRI-detected sources, including ~1200 bright, dusty sources directly detected with ALMA out to z~6, and an additional ~120,000 sources with NIRCam-only detections from stacking. With this large area we will find dusty high-z galaxies and provide limits to sub-mm properties of fainter sources via stacking. This program provides a unique opportunity to combine cutting-edge multiwavelength data to robustly measure the amount of obscured star formation across cosmic time, and the evolution of the dust and gas properties of galaxies and AGN. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2025-06-24T21:58:16.000 |
| 2555 | 2013.1.00652.S | 14 | Spying on our Neighbor: Peering into Low Metallicity Molecular Clouds in the Small Magellanic Cloud | A dominant reservoir of H2 gas faint in CO emerges as metallicity decreases, which alters the structure of molecular clouds and perhaps the sites of star formation. With ALMA, we can reach the resolution necessary to see the structure of photodissociation regions and the transition from ``CO-bright'' to ``CO-faint'' molecular gas for the first time at 1/5 Solar metallicity in the Small Magellanic Cloud. We propose to map four regions in the Southwest Bar of the SMC at high spatial and spectral resolution (1.6" or 0.5 pc scales and ~0.1 km/s) in 12CO, 13CO, and C18O (2-1). We will determine the mass, structure, and kinematics of molecular clouds across a range of environments. We will explore the structure of CO gas, the transition to CO-faint molecular gas, and the effect of the CO-faint molecular gas on low metallicity star formation. With the slew of ancillary data in hand (much collected by the Co-Is in this proposal), including PAHs, [CII], [CI], [NII], [OI], dust continuum, and dust-based H2 maps, we can fully exploit the ALMA observations and answer key questions needed to inform ISM and star formation models used in galaxy simulations. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2016-02-03T13:57:57.000 |
| 2556 | 2018.1.00279.S | 111 | High Resolution Survey of the Gas and Dust Distribution in Nearby Luminous Infrared Galaxies | We propose to observe six of the closest U/LIRGs which we have already observed with the VLA at 0.1 at 33 GHz. ALMA observations at Band 3 and 7 will resolve the nuclear warm molecular gas and dust, ideal for comparison to our star-formation tracing VLA data. By combining 100 and 33 GHz continuum, we will diagnose the nature of the radio continuum at each point in the nuclear disk. Our observations will provide a strong test of the common assumption that the sizes inferred from optically thin, star-formation radio continuum also describe the distributions of gas and dust. From the high resolution CO and dust data, we measure the structure and kinematics of the gas in the inner disk. In addition to dynamical mass estimates and constraints on SMBH masses, these measurements are crucial to understand if the local ULIRG population indeed consists of radiation pressure limited maximal starbursts. This is a resubmission of an accepted B-ranked Cycle 5 proposal for which at the time of this submission it is 50% completed. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2020-11-28T23:25:47.000 |
| 2557 | 2016.1.00336.S | 7 | "Dipping" into Terrestrial Planet Formation | Promising new probes of terrestrial planet formation are the so-called "dipper" stars, whose optical and infrared light curves exhibit episodic day-long drops in flux. Dippers exhibit infrared excesses indicative of protoplanetary disks and their dips are consistent with extinction by transiting dust clouds near the star-disk co-rotation radius. Current mechanisms explaining the dippers require edge-on viewing geometries, as they invoke occulting structures orbiting in a thin disk. Surprisingly, the three dippers with archival high-resolution ALMA data span the full range of disk inclinations, from face-on to edge-on. We therefore propose high-resolution, high-sensitivity ALMA observations to establish the inclination distribution of the dippers and distinguish between competing mechanisms. Confirming an isotropic inclination distribution would favor models with interesting implications for terrestrial planet formation, including disk warps caused by inclined protoplanets and scattered planetesimals due to migrating planets. Studying the dippers will help us better understand terrestrial planet formation at < 1 AU, a region otherwise difficult to probe even with interferometry. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2019-03-01T17:27:00.000 |
| 2558 | 2021.1.00287.S | 3 | mm polarization properties of the flaring jet during a new pecular accretion state in microquasar GRS 1915+105 | Polarization observations in the millimeter regime are crucial in determining the magnetic field structure close to the jet base in active galactic nuclei and providing discriminatory power in the determination of the proper model for the jet structure. However, mm-band linear polarization measurements are lacking from jets around stellar-mass black holes. Given their small black hole masses, they evolve through a wide range of accretion rates on timescales accessible to people providing unique opportunities to study jet evolution. Here, we propose an ALMA observation of a transient black hole X-ray binary GRS 1915+105 that has recently changed radio properties from a nearly quenched state to a flaring state indicating an activation of the jet. Also, X-ray observations show signs of obscuration, that has never been seen before. We would like to use this unique opportunity to study the mm polarization properties of the flaring jet in GRS 1915+105 with ALMA together with supporting X-ray observations. This data would provide us a quantitative understanding of the physics involved in jet production and its connection to the accretion flow in this peculiar state of accretion. | Black holes, Transients | Stars and stellar evolution | 2023-09-23T09:30:14.000 |
| 2559 | 2021.1.01309.S | 14 | Into the (infrared-)darkness: the chemistry, kinematics and structure of massive core candidate | Massive stars are critical for the baryonic cycling of galaxies, however, we do not currently know how they are formed. There are two theories for their formation, which posit two very different initial gas density distributions - either monolithic or fragmented cores. However, monolithic cores are extremely rare, and only a handful of candidates are currently known to exist, and, hence, the study of any such regions are extremely valuable if differentiating massive star formation theory. We have identified a quiescent (no star formation), massive (>40Msun) region, which, with ancillary observations, presents a very promising candidate for a monolithic core. With the proposed (0.5arcsec, 0.01pc) observations we aim to investigate the kinematic and chemistry of this region using a particular line of interest - H2D+. These observations will allow us to confirm the cores quiescent evolutionary state, determine their physical and dynamical properties, and constrain chemical models (via measurement of the o-H2 to p-H2 abundance ratio). In all, for a relatively small amount of ALMA 12m time (<5hour), we will be able to conduct a series of key tests for massive star formation theory. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-12-22T10:10:51.000 |
| 2560 | 2018.1.00262.S | 17 | An Ultimately High Angular Resolution Synoptic Observation for Fragmentation in an OB Cluster-Forming Molecular Clump | At the convergences of accreting dense molecular gas filaments, which are likely sites to form the highest mass stars in a stellar cluster, the effects of angular moment may become prominent. Our ALMA and ACA cycle-1 observations towards the ~1 pc scale, ~5000 M_sun OB cluster-forming molecular clump G33.92+0.01 A have resolved the intriguing morphology of gas spiral arms embedded with localized dense molecular cores, which are orbiting the two ~200 M_sun centralized massive cores. Our follow-up, 0".15 resolution (1100 AU) observations further resolved that the centralized massive cores are fragmenting, forming internal sub-clusters. These observations demonstrate the hierarchical, self-gravitational fragmentation of the Toomre unstable accretion flow over an extremely broad range of spatial scales. We request follow-up observations at the best possible angular resolution, 0".019 (135 au), to resolve multiplicity inside all ~1000 AU scale circumstellar envelopes we identified. Our main goal is to make a very deterministic test of fragmentation and YSO formation in such system, thereby improve our understanding of the high-mass end of the stellar initial mass function. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-11-08T12:00:22.000 |
| 2561 | 2023.1.00439.S | 0 | Probing a temperature enhancement at the disk-envelope interface | One of the main open questions in understanding planet formation and composition is whether the planet-forming material in the circumstellar disk is directly inherited from the natal cloud or modified en-route to the disk. Similarities in molecular abundances between protostellar envelopes and comets favor the inheritance scenario. On the other hand, observations pointing at chemical changes at the disk-envelope interface suggest at least some form of change, potentially when the infalling material undergoes an accretion shock when entering the disk. So far, chemical changes at the disk-envelope have only been observed toward a handful of protostars and a shock origin has not been established unambigously. Recent high angular resolution observations of the protostar L1527 show hints of a temperature increase at the disk-envelope interface; the first sign of a change in physical conditions in this region. Here, we propose high spatial and spectral resolution follow-up observations of multiple H2CO lines to constrain the location of the temperature enhancement with the potential to deliver the first solid evidence of an accretion shock at the boundary between envelope and disk. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 2562 | 2018.1.01255.S | 52 | Misaligned Inner and Outer Disks in Dipper Stars | The revolution of space based monitoring (e.g. with K2) has revealed a new category of young stellar objects, called dippers. Their optical light curves exhibit periodic or transient dimming events which result from dusty circumstellar material repeatedly crossing the line of sight and obscuring the central star. Dippers represent ~30% of young stellar objects and are thought to be accreting young systems seen at high inclination, almost edge-on. Yet, our recent images of dippers, including the prototype of the dippers, AA Tau, revealed outer disks with moderate inclination, suggesting that their inner disk is misaligned with respect to their outer disk. We propose here to study three dippers with large cavities, at high angular and spectral resolution, to study both their inner and outer disks, understand the origin of the cavity, and search for direct evidence of a warped inner disk in both continumm and kinematical signatures. | Disks around low-mass stars | Disks and planet formation | 2022-10-01T00:00:00.000 |
| 2563 | 2022.1.00049.S | 900 | Towards a sample of SMBH shadows, rings, accretion flows and jet bases: ACA fluxes of SMBHs with large photon rings | The photon ring around the supermassive black hole (SMBH) in M87 has been imaged with the Event Horizon Telescope (EHT), and results on SgrA* are in the pipeline. With ALMA passive-phasing, the EHT can now detect sources of a few 10s of mJy. Additional SMBH photon rings are likely resolvable by the EHT, but these SMBHs are faint at centimeter radio (weak/no jets), and their 230 GHz flux (accretion inflow) is unknown. We propose to measure the 230 GHz flux of 23 SMBHs with photon ring > 5 microarcsec (piggy-backing 77 more SMBHs with photon ring > 2 microarcsec). i.e., a total of 100 'large ring' SMBHs. Those with nuclear flux > 10mJy will be followed up with the 12m array, VLBA, and eventually the best with EHT. Our longer term goals are to identify all SMBHs in which the EHT can resolve the photon ring and jet base, and to drive the technical requirements of the next-generation-EHT. Even only a few new EHT-feasible 'large ring' galaxies will allow the transformational results in M87 and SgrA* to be leveraged to a larger number of galaxies. Our sample includes the most massive SMBHs: the continuum (and CO line of the first galaxy of the SG) is a useful archival resource. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-10-11T15:20:54.000 |
| 2564 | 2018.1.01806.S | 139 | Detecting hot quasar winds via the Sunyaev-Zel'dovich Effect | Quasar-driven winds can significantly impact their large-scale environments. The winds are likely composed of different phases including a hot volume-filling plasma and cooler, high-density clumps or filaments. The hot plasma is the most difficult to observe as any emission associated with it would be weak, yet investigating this component is crucial for characterizing quasar winds and quantifying their impact on the surrounding medium. The hot, volume-filling component of quasar winds can potentially be detected via the Sunyaev-Zel'dovich (SZ) effect, the scattering of CMB photons off of free electrons in the hot gas. The SZ effect creates a decrement below and an increment above 220 GHz in the observed spectral energy distribution (SED). We propose to observe two quasars at 90 GHz and 150 GHz to detect the decrement in the SED of the quasars due to the SZ effect. We also propose to observe the targets at 220 GHz, where the SZ signal is null, in order to anchor the SEDs relative to the SZ decrement. In carrying out these observations, we will open a new window into the studies of quasar feedback by detecting this effect in individual quasars for the first time. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-10-23T16:40:00.000 |
| 2565 | 2019.1.01422.S | 77 | Molecular gas properties of HI 21-cm absorption-selected galaxies at 1<z<2 | ALMA observations of absorption-selected galaxies have so far focussed at z<1 and z>2. The intermediate redshift range 1 | Damped Lyman Alpha (DLA) systems | Cosmology | 2021-04-20T12:57:42.000 |
| 2566 | 2017.1.01676.S | 75 | ALMA followup to the S2-WEB survey: Constraining the fraction of molecular outflows in the most luminous QSOs | We propose ALMA CO(3-2) & CO(7-6) followup to a sample of hyper-luminous QSOs, L(UV)~10^14 Lsun, at z=2.5-2.8 drawn from the SCUBA-2_WEB survey of the Keck Baryonic Structure Survey (KBSS) fields. Two factors have brought this ALMA followup survey to the forefront: (i) In the one KBSS-HLQSO we've followed up in CO, HS1549+19 (Chapman et al. 2017), we see a large 8kpc FWHM molecular disk, and an enormous molecular outflow (5x10^10Msun) extending spatially to 10kpc and to velocities >1500km/s, the largest outflow known in the Universe, and potentially an important evolutionary stage of massive galaxies; (ii) Our SCUBA-2 maps have shown 13/13 of of the QSOs to be bright S_850um~8mJy sources (Ross et al. 2017), completely at odds with submm followup statistics of QSO samples from past surveys. In many cases, the extended and sometimes offset 850um detection is suggestive of companion SMGs around the QSO, which the band3 and band6 followup will probe. These proposed observations will also initiate the precise identifications of SMGs near the QSOs which are a prerequisite to study the effect of SMGs on the circumgalactic medium, using the HLQSO sight lines. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2019-12-18T22:50:46.000 |
| 2567 | 2015.1.01008.S | 2 | Mapping Infall in Filamentary Environments: A Study of three Orion Class 0 Protostars | We propose to use the Orion A cloud as a laboratory to study the processes that control low mass star formation by mapping infall in three Class 0 protostars found in dense filaments, each selected to be in a region with different environmental properties. We will adapt an approach used to map infall in massive protostars to low mass protostars, using C18O (2-1) and simultaneolusly obtained 13CO and 12CO lines, to map the acceleration of the infalling gas near the protostar. The interpretation of this acceleration is potentially less model dependent than the red-shifted absorption profiles commonly used in infall measurements. Combined with measurements of the envelope structure from simultaneous dust continuum mapping and Spitzer/Herschel/APEX SEDs, the infall motions will provide the rate of mass infall onto the protostar, and the dependence of mass infall rate on environment. We will use 12 m, ACA and TP observations for this pilot study to identify the minimum data needed for larger surveys of infall. These data will also be compared to a similar Cycle 2 study of Class I protostars to study the evolution of infall between the Class 0 and I phases. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-06-05T19:51:52.000 |
| 2568 | 2022.1.00383.S | 0 | Constraining Accretion and Ionizing Feedback of a Very Massive Protostar via High-frequency Multi-band Observation | Forming massive stars become so luminous that their ionizing feedback may stop the accretion and limit their further growth. In order to investigate the ionization feedback and accretion processes in the formation of very massive stars, we propose ALMA Bands 8, 9, and 10 continuum observations toward the massive forming star G45.47+0.05. Previous VLA and ALMA Bands 6 and 7 observations reveal an hourglass-shape bipolar photoevaporative outflow in this source with evidence of on-going accretion. The small-scale continuum emission up to Band 7 is dominated by free-free emission of ionized gas. We aim to probe the dust component of the neutral disk where the ionized outflow is being launched. The multi-band high-frequency observation is needed to constrain both the properties of the dusty disk and the ionized outflow. These observations will put strong constraints on how feedback and accretion processes interact with each other around a forming star of at least 40 solar masses. This proposal also aims to demonstrate the importance of ALMA high-frequency bands in probing the inner densest part of photoionized regions around massive forming stars. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2024-11-24T17:32:17.000 |
| 2569 | 2016.2.00055.S | 259 | An Unbiased Search for High Velocity Winds in local (U)LIRGs using the 7m Array | We propose to use ALMA 7m array stand alone observations to carry out a complete, flux-limited, survey of 14 equatorial (U)LIRGs in the GOALS sample. The main goal is to obtain a high SNR measurement of the CO(2-1) line in order to test for the presence of high velocity components, >500 km/s, that would indicate the presence of outflows in these sources. This will allow us to estimate the incidence of molecular outflows in a statistical sample of star forming galaxies and test for possible dependences on physical parameters such as star formation rate, presence of AGN, merger stage, etc. Molecular outflows have been shown to be potentially critical in galaxy transformations and therefore a fundamental ingredient in our understanding of galaxy evolution. This program takes full advantage of the unique 7m array as a standalone facility, will provide short spacing data for ALMA 12m observations of the sample and will greatly enhance the rich multiwavelength data available for these sources, thus ensuring the strong legacy value of this proposed dataset. | Surveys of galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-10-09T07:31:37.000 |
| 2570 | 2013.1.01262.S | 9 | Quasars Probing Quasars: CO observations of projected quasar pairs | We have compiled a large sample of close projected QSOs pairs, with small transverse separations (<100kpc) but large line-of-sight separations, such that the QSOs are physically unassociated. In these unique sightlines, optical absorption lines in the background QSO spectrum encode information about the state of cold gas in the foreground QSOs ISM/halo. Our measurements indicate that QSOs at z~2 are surrounded by significant reservoirs of cold gas on ~30-100 kpc scales, with extreme kinematics. This could be the first detection of the so-called cold mode of cosmological accretion, proposed as the primary mechanism for fueling galaxy formation. In this proposal, we request sensitive CO(3-2) observations to measure molecular gas masses and kinematics in three of these systems. This will allow us to connect for the first time the small scale molecular gas reservoirs of galaxies to their larger scale ~30-100 kpc supply of cold gas. These measurements will provide critical constraints to the mechanisms responsible for the supply of cold gas in massive galaxies. | High-z Active Galactic Nuclei (AGN), Damped Lyman Alpha (DLA) systems | Active galaxies | 2016-09-04T23:20:14.000 |
| 2571 | 2023.1.01062.S | 0 | Probing the jet-ISM interaction in low-z radio-quiet quasars | We propose ALMA observations of the CO(2-1) line emission from a sample of four low-z radio-quiet Palomar-Green (PG) quasars. These objects exhibit extended radio emission on a scale of ~2kpc that is likely associated with AGN activity. Though the radio power is not as strong as that of the radio-loud ones, they provide an ideal sample to investigate the interaction between the weak/uncollimated jet and the star-forming ISM in the quasar host galaxies. With a requested resolution of 0''.3~0''.7 (equivalent to approximately 0.5-1.1 kpc), we expect to resolve the molecular gas in at least six beams along the major axis, as validated by simulations performed using the CASA task simobs. By resolving the CO(2-1) line emission in this quasar sample, our objectives are as follows: 1) To investigate the degree of disturbance in the cold gas within low-z quasars displaying prominent extended radio emission, 2) To evaluate whether the cold gas is redistributed by the weak jets/winds, and 3) To estimate the star formation efficiency by modeling the spectral energy distribution and evaluate whether star formation is enhanced or suppressed in these quasar host galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-01-08T13:56:58.000 |
| 2572 | 2017.1.01180.S | 51 | Kinematically Detecting Warps in the Disks of Dipper Stars | Up to 30% of the classical T-Tauri star population shows signs of the so-called `dipper' phenomenon, a quasi-periodic deep flux variation occurring every few days, and lasting for day-long timescales. For decades the accepted mechanism for this behavior has been the periodic occultation of the star by a warped inner disk viewed at a high inclination. ALMA observations of the disks around these stars have challenged this explanation, however, finding a wide variety of inclinations for the visible outer disks. These discrepant observations can be reconciled through a system geometry of misaligned inner and outer disks. Recent observations of the disk around the archetypical dipper star AA Tau have found evidence for just such a geometry, specifically showing kinematic signatures of a disk warp between the inner and outer disks. A larger sample is needed, however, before concluding that this explanation holds for all dippers. We propose observations of two dipper stars that host large and bright disks, aiming to find kinematic evidence for a warp and constrain the degree of misalignment between the inner and outer disks. | Disks around low-mass stars | Disks and planet formation | 2019-02-19T22:42:17.000 |
| 2573 | 2017.1.00681.S | 41 | Zooming in on the parsec-scale structure of CO gas at low metallicity and its relation to star formation | The star formation rate is proportional to the surface density of molecular gas, for a wide range of metallicities. Models predict that the structure of CO-emitting gas should change with metallicity and radiation field: extended CO emission and CO "clumps" should shrink as metallicity decreases or radiation field strength increases. This effect has never been directly observed before, and models of CO formation have not been put to a test. Additionally, the effects of those changes on the star formation process, which occurs in dense, CO-emitting gas, are unknown. We propose to obtain deep maps of two transitions (1-0 and 2-1) of three CO isotopes (12CO, 13CO, and C18O) in 6 regions of two low-metallicity galaxies, the LMC and the SMC. These observations will allow us to test CO photo-chemical models by providing deep maps of the pc-scale structure, column density, thermal, and chemical state of the CO-emitting gas at two low metallicities and a range of radiation fields. By comparing the CO maps to pc-resolution tracers of star formation, specifically 24 micron emission and young stellar objects, we will bridge the gap between Galactic and extragalactic star formation studies | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-06-18T19:25:03.000 |
| 2574 | 2016.1.01019.S | 24 | Tracing the Origins of Nitrogen Bearing Organics Toward Orion KL | A comprehensive analysis of a broadband 1.2 THz wide spectral survey of the Orion Kleinmann-Low nebula (Orion KL) has shown that nitrogen bearing complex organics trace systematically hotter gas than O-bearing organics toward this source. The origin of this O/N dichotomy remains a mystery. If complex molecules originate from grain surfaces, N-bearing species may be more difficult to remove from grain surfaces than O-bearing organics. Theoretical studies, however, have shown that hot (T=300 K) gas phase chemistry can produce high abundances of N-bearing organics while suppressing the formation of O-bearing complex molecules. We propose here to map, in exquisite detail, the temperature structure and D/H ratio of the complex N-bearing organic methyl cyanide (CH3CN) toward the Orion KL hot core. If gas phase formation routes are significant at high temperatures, we will observe a decreasing gradient in the D/H ratio of CH3CN with increasing kinetic temperature. The proposed observations will shed light on the origin of all complex N-bearing organics in the interstellar medium. | High-mass star formation, Astrochemistry | ISM and star formation | 2017-12-15T01:15:44.000 |
| 2575 | 2023.1.00442.S | 0 | Are there dynamically cold disks at z > 5? | Dusty star-forming galaxies (DSFGs) at 4 5 is crucial for testing these as this is the timescale over which the dynamical properties of galaxies, according to novel predictions, should differ the most. Through the FRISA (Finding Rotation In Starbursts with ALMA) project, we propose high signal-to-noise observations for 8 DSFGs at 5 | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2025-07-17T17:54:18.000 |
| 2576 | 2016.1.01175.S | 27 | The most massive galaxy cluster above redshift 1: anatomy of a cool core | We propose to make Sunyaev-Zel'dovich observations of the high-redshift, z = 1.13, galaxy cluster SPT-CL J1206-5844. The X-ray derived 3-bin temperature points towards the presence of a cool core in its centre, while the measure of X-ray concentration peakedness suggests otherwise. Given these uncertainties in the X-ray derived properties, primarily caused by the lack of photon number counts at this redshift, we want to use joint ACA Band 3 and Band 4 to image the core region via the Sunaev-Zeldovich effect in order to differentiate between the presence of a classical cool-core or, indeed, a more shallow pressure profile, shedding light on the feedback processes and gas cooling regulations in this cluster. Being the most massive cluster above redshift 1 and thus situated within an overall early cluster formation epoch, this pathfinder study stresses the need for SZ high-resolution observations that can significantly complement X-ray data in morphological cluster analyses at high z. | Galaxy Clusters | Cosmology | 2018-04-19T15:02:14.000 |
| 2577 | 2018.1.01441.S | 19 | First resolved observation of the isolated, high-mass circumstellar disk candidate G19.01-0.03 | High-mass stars are key constituents of a galaxy. Understanding how they gain mass is however elusive. Models suggest that high-mass stars accrete material through circumstellar discs similarly to low-mass stars, however only a few candidate Keplerian discs have previously been observed surrounding O-type (proto)stars. Whether discs fragment due to gravitational instabilities is debated, with disagreement between simulations. Observationally, studies are limited by resolution, and only ALMA can provide the necessary resolution to resolve them. We propose to observe G19.01-0.03 at the high angular resolution (0.09''~360AU at 4kpc), with the goal of resolving its multiplicity (or lack thereof). G19.01-0.03 is a high-mass Keplerian disc candidate with an enclosed mass of 20-40Msun driving a collimated bipolar outflow. Identified in the Extended Green Object (EGO) catalog, this source is the current best example of a truly isolated disc/outflow system, with only a single mm-continuum source resolved in the field. With such a high enclosed mass for a source with a luminosity of only 10^4Lsun, G19.01-0.03 can provide key insight into how high-mass stars gather their mass. | Disks around high-mass stars | Disks and planet formation | 2021-01-03T00:00:00.000 |
| 2578 | 2022.1.01758.S | 12 | Investigating grain growth in a structureless protoplanetary disk | Substructures acting as dust traps in protoplanetary disks are the currently accepted solution to the fast radial drift of mm/cm-sized grains, which would otherwise deplete the disk of large grains quickly and prevent planet formation. A puzzling source in this context is the evolved (3-17 Myr) protoplanetary disk around the nearby (100 pc) solar analog MP Mus: despite its age, 1.3 mm archival ALMA observations do not reveal any substructure down to 6 au scales. Here we propose to obtain 3 mm observations with a similar angular resolution to investigate whether large grains are present in the disk. Combined with the existing 1.3 mm data, this will result in a spatial map of the disk spectral index (sensitive to grain sizes), enable detailed modeling of the dust properties and disk structure, and allow us to search for substructures at optically thinner wavelengths. If large grains are found in the disk, then very small ($<6 au) unresolved substructures may be responsible for stopping their migration. On the other hand, if only small grains remain, this could imply than planets need to form much faster than expected before mm-sized grains disappear from the disk. | Disks around low-mass stars | Disks and planet formation | 2024-08-10T13:16:16.000 |
| 2579 | 2013.1.00914.S | 4 | Mapping dust and gas in very-massive, intensely-star-forming galaxies at z~2 | Deep Herschel surveys have revealed a population of very-massive (few 10^11 Msun), intensely-star-forming (200-500 Msun/yr) galaxies at the massive-end of the famous main-sequence at z=2, when the star formation rate density in the Universe was maximum. Understanding the physical processes driving such intense star formation is a difficult challenge. In addition, statistical studies show that these galaxies will stop to form stars soon and that they are hosted by massive halos, what are progenitors of clusters. This population could thus be a key to understand the formation of massive, passive galaxies at high redshift. To better understand their nature, we propose to perform a low-resolution imaging of the dust and gas for a pilot sample of four galaxies. These data will address several hot questions: can the intense star formation in these objects be explained only by large gas reservoirs? How is the gas and dust distributed (disk vs bulges, presence of clumps)? Are these objects rotation- or dispersion-dominated? Is their XCO factor closer from local spiral or starbursts? Do their environment contain star-forming satellites? | Galaxy structure & evolution | Galaxy evolution | 2017-09-02T00:00:00.000 |
| 2580 | 2023.1.00510.S | 0 | B(and1)EARS: Low-J CO survey for BEARS | Measuring the total molecular gas mass as a fuel of star formation in dusty star-forming galaxies (DSFGs) at the cosmic noon is essential to understand the most extreme phases of galaxy formation and evolution. While mid- or high-J carbon monoxide (CO) emission lines are commonly used to trace molecular gas at high redshift, there are often significant uncertainties in CO excitation conditions. To address this issue, we propose the observations of low-J CO emission lines for the 25 BEARS samples using Band 1, a new frequency window of ALMA. The BEARS samples consist of not only strongly lensed sources but also non-lensed hyper-luminous infrared galaxies with mid- and high-J CO emission lines that were detected in previous ALMA cycles. Our primary science goals are to constrain the CO excitation conditions between mid-J and low-J emission lines and to measure the total molecular gas mass in each galaxy from low-J CO observation. In addition, we can also serendipitously detect line emitters with ALMA Band 1's large field of view. This proposal will yield the first ALMA catalogue of low- and mid-J CO observed DSFGs. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-05-28T01:55:19.000 |
| 2581 | 2011.0.00656.S | 0 | Deuterium Fractionation in the IRDC clump G34.43+00.24 MM3 | We propose to observe the HN13C, DNC, N2H+, and N2D+ J=3-2 lines toward the infrared dark cloud(IRDC) clump, G34.43+99.24MM3, to examine our idea of extracting the initial condition of high-mass star formation from the deuterium fractionation ratios observed in the star-forming clump. From our previous single-dish observation (HPBW~18”), the DNC/HNC ratio of high-mass sources is found to be systematically lower than that of the low-mass sources. Taking the time dependence of the deuterium fractionation into account, the low DNC/HNC ratio does not reflect the current temperature, but it may suggest that the cold starless phase is shorter than that of the low-mass cores, or that the initial temperature is higher. However, we need to evaluate the DNC/HNC ratio at a higher angular resolution with ALMA for a fair comparison with the ratio in low-mass cores under the similar physical size scale, considering that high-mass sources are more distant than low-mass sources. For this purpose, we select G34.43+00.24MM3, which has the lowest DNC/HNC ratio in the sample of our previous single-dish observation. By higher angular resolution (3”) observations with ALMA, we will investigate the deuterium fractionation ratio in the innermost part of the clump, which is directly related to the star formation. If we confirm the low DNC/HNC ratio in the innermost part of the clump, we can state that the initial conditions are different between low-mass and high-mass star formations. Furthermore, we wish to investigate how the star formation activities affect the deuterium fractionations, by comparing the distribution of DNC/HNC ratio with those of the N2D+/N2H+ ratio and the shocked gas tracers, like SiO and CH3OH. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2013-12-05T19:14:00.000 |
| 2582 | 2019.1.00379.S | 30 | Constraining Ionization in a Diverse Sample of Protoplanetary Disks | Ionization is influential in shaping both physical and chemical structure in protoplanetary disks. However, ionization is poorly constrained in observed disks, with strong constraints towards only one source, TW Hya. In this disk, it was found that ionization from cosmic rays is suppressed by two orders of magnitude, implying that coupling of disk material to magnetic fields may be too weak to explain angular momentum transport in this system. We propose a survey of ionization-tracing molecular ions towards seven physically well-characterized disks that will complement existing observations in the ALMA archive to place constraints on ionization in a diverse disk sample. In addition to verifying whether or not the low ionization levels observed in TW Hya are typical, the proposed observations will have implications for the cold ionization-driven chemistry occurring in these disks, which governs the formation of water and complex organics, and will additionally supply realistic, observationally motivated ionization models for future disk physical modeling, namely magneto-hydrodynamic (MHD) simulations. | Disks around low-mass stars | Disks and planet formation | 2022-04-15T20:29:55.000 |
| 2583 | 2011.0.00170.S | 0 | Interstellar Glycine | Many COMs found in interstellar clouds are prebiotically important and have essential functions in terrestrial biochemistry. Many COMs, including amino acids, have also been found in primitive meteorites, and glycine, the simplest amino acid, was detected in comet Wild 2. Although the formation of prebiotic molecules in extraterrestrial environment and their contribution to the origin of life remains unsettled, the connection between interstellar organic chemistry, meteoritic amino acids and the emergence of life on early Earth would be strengthened with discoveries of prebiotic molecules and glycine. Kuan et al. (2003) reported the detection of glycine in Orion KL; however, the detection was disputed by Snyder et al. (2005) mainly because of a “missing” line at 113,336 MHz in Orion KL. Lately this “missing” line was successfully detected in Orion KL thus becomes the pivotal result which reinstate the validity of the original glycine detection. To overcome the chance interloper problem and to diminish the blanketing effect caused by line forest often seen in SD data, we must use ALMA for unequivocal confirmation of interstellar glycine. ALMA will not only offer us a unique opportunity to distinguish targeted lines from interlopers spatially but also provide the detailed, fine kinematic information at each location within the FOV. By imaging precisely the locations of glycine emission showing consistent kinematical signature, misidentification of chance interlopers will less likely happen. Given the significance of interstellar glycine for astrobiology and the great potential interest of the general public, we thus propose to observe 32 glycine lines in Band 6 plus the 113-GHz line in Band 3 toward Orion KL to confirm the glycine detection. With the incredible spectral sensitivity and wideband capability of ALMA, we will be able to settle this fundamental issue which has lasted for over 30 years in 9 hours. | Inter-Stellar Medium (ISM)/Molecular clouds, Astrochemistry | ISM and star formation | 2014-03-16T11:31:00.000 |
| 2584 | 2022.1.01705.S | 46 | Physical properties of the molecular medium across the circum-galactic environment in a sample of four quasars | At high redshifts, giant Ly-alpha nebulae play a crucial role in the evolution of massive galaxies, but their link to stellar growth critically depends on the properties of the coldest, molecular gas phase. ALMA observations of CO(4-3) in Cycle-7 and 8 revealed extended (~100 kpc) reservoir of cold molecular gas in a sample of four Ly-alpha nebule at z=2.22~2.31. We propose ACA observations of simultaneously CO(7-6) and CI(2-1), which will complement existing ALMA and VLA data of CO(4-3), CI(1-0), and CO(1-0). This suite of molecular tracers will allow us to study the physical properties of the cold gas (e.g., mass, temperature, excitation conditions, and radiation field) simultaneously across different environments (QSO host, CO/[CI] emitters, molecular outflow, and molecular CGM). This will allow us to investigate the cold baryon cycle that drives the early evolution of these massive galaxies at cosmic noon. | Lyman Alpha Emitters/Blobs (LAE/LAB), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2024-07-31T16:47:53.000 |
| 2585 | 2015.1.00782.S | 32 | ALMA-LEGUS: The Impact of Spiral Arm Structure on Molecular Cloud Properties and Star Cluster Formation | The impact of spiral structure and feedback from stellar populations on molecular clouds has broad-ranging implications for star formation in the present day universe. We propose to map the CO(2-1) emission on ~14-19 pc scales of two well-chosen disk galaxies, NGC1313 and NGC7793, which have similar masses, star formation rates and morphologies, but have very different spiral structures and widely different stellar cluster properties. These galaxies were observed as part of the HST Treasury program LEGUS (Legacy ExtraGalactic UV Survey), and we have derived the star formation histories, and cluster ages and masses. The unprecedented ALMA/LEGUS synergy will provide a comprehensive investigation of star formation in spiral galaxies by connecting the resolved molecular properties with detailed stellar population information. Specific issues to be addressed include: the timescales over which star formation occurs in molecular clouds, the lifetimes of clouds, and the role of star formation in the gas turbulence. We will compare our results with our predictions from simulations, to guide next-generation models of star formation and galaxy evolution. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2018-03-20T19:28:56.000 |
| 2586 | 2021.1.00798.S | 3 | Imaging the Magnetized Cold Gas Accretion within 0.5 pc of the supermassive black hole SgrA* | The magnetic fields (B-fields) anchored in the circumnuclear disk (CND) of the Galactic center (GC) are expected to remove/transport the excess angular momentum out of the CND gas, by magnetic stress, thereby facilitating the accretion of cold CND gas onto the supermassive SgrA*. Our previous attempt to map the B-fields in the CND with the JCMT shows that the CND appears to be magnetized in an organized fashion. Furthermore, the radial inflows, at the level of about 25% of the Keplerian motion, required to explain the CND kinematics are consistent with the CND B-field configuration. In this proposal, we ask the key questions: (1) to what extent the B-fields are threaded into the CND gas and continue inwards with the recent infall (nuclear streamers) as detected by ALMA, (2) can the B-fields become stronger to stabilize the accretion? With ALMA, we aim to detect and resolve the magnetized inflows within 0.5 pc of SgrA*. By measuring the field orientation and the strength, we aim to determine how efficiently the B-fields can guide the accretion process, thereby setting the first constraint on the role of the B-fields in the cold gas accretion near a supermassive black hole. | Galactic centres/nuclei | Active galaxies | 2023-09-05T20:32:00.000 |
| 2587 | 2018.1.01565.S | 536 | Tracing the accretion history of protostars using outflows, an ACA+TP survey | We propose an ACA+TP (5.5" resolution) outflow survey of 29 protostars in the Orion clouds observed in high-J CO with Herschel/PACS. The high-J CO line luminosity is a measure of the instantaneous mass outflow rate. In contrast, low-J CO emission is a measure of the time averaged mass outflow rate. For our sample, we have shown that the high-J CO emission exhibits a strong correlation with the protostellar L_bol, demonstrating a linkage between instantaneous mass outflow and mass accretion rates. Analyses of other samples of protostars in low-J CO lines show the time averaged mass outflow rate correlates with L_bol, but surprisingly there is also a steady decline in time averaged mass outflow rate with protostellar age. These observations will directly address the difference between instantaneous and time averaged mass outflow rates using uniform observations of a well-characterized sample of protostars. We will: 1. measure the momentum flux and mechanical luminosity of the outflows; 2. establish their dependence on Lbol and protostellar evolutionary class; and 3. place high- and low-J CO informed constraints on the time evolutionary history of mass accretion in protostars. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2020-07-06T00:41:31.000 |
| 2588 | 2018.1.00446.S | 21 | Understanding the launching mechanism of ionized winds in massive protostars | Massive stars strongly ionise their surroundings forming UC HII regions. The kinematics of the ionised gas can be probed by hydrogen radio recombination lines (RRLs). A few objects present maser effects in their RRL emission and thanks to their large amplification, one can study in great detail the kinematics and physical structure of the innermost, ionised regions around massive protostars. Recent high-angular resolution images (beam ~0.08"x0.06", 70au x 50 au) of the H21alpha line obtained with ALMA toward the MonR2-IRS2 massive YSO, have resolved for the first time the ionised gas for radii <85 au (<0.1"). The gas seems to be distributed into possibly a disk and a high-velocity ionised wind. The reached sensitivity and angular resolution was however insufficient to study in detail the kinematics of the putative disk and of the high-velocity gas associated with this source. We propose to image the H26alpha line in Band 7 at an angular resolution of 0.03" (~25 au) to constrain the structure and kinematics of the disk and to establish the launching radius of the wind. This will allow us to determine the most likely launching mechanism for ionized winds in massive protostars. | Outflows, jets and ionized winds | ISM and star formation | 2020-11-29T21:13:26.000 |
| 2589 | 2015.1.01115.S | 224 | The first Gigayear of the Universe: A census of dust and gas in z>6 quasars | Optically-selected quasars have been detected well into the epoch of reionization, indicating the existence of supermassive black holes (SMBH) within one Gyr of the Big Bang. FIR continuum and line observations of selected sources have revealed that quasar hosts often show intense star formation and massive, enriched gas reservoirs. We propose to observe an accretion-rate-limited sample (35 quasars total, the majority recently discovered by us using Pan-STARRS1) in [CII] and continuum emission, spanning a factor of ~20 in quasar bolometric luminosity, ~40 in SMBH mass, and ~100 in FIR luminosity. This critical five-fold increase in sample size was simply inconceivable pre-ALMA. We will study the fraction of high-z quasars associated with massive starbursts, will reveal any correlation between SMBH accretion (+ Eddington ratios) and star formation, and will constrain ISM masses. [CII] observations will provide first insights on the host dynamics, feedback, and on cosmic reionization through precise redshift measurements. This first population study of SMBH-galaxy coevolution at the highest accessible redshifts can conveniently be scheduled as time fillers. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-06-22T10:14:48.000 |
| 2590 | 2017.1.01695.T | 14 | Chemistry of high-z star-forming regions probed with GRB afterglows | We propose to use long gamma-ray burst (GRB) afterglows as beacons to study the chemistry of high-redshift star-forming regions. This technique will open a new window to observe molecular gas at a wider range of redshifts and galactic environments. This is a single trigger target of opportunity proposal where we will obtain spectroscopy of a bright GRB afterglow, and covering as many molecular features as possible, with particular interest in CO and HCO+ absorption features. The exact spectral features that will be observed will depend on the redshift of the GRB. It will be the first time that GRBs are used at millimetre wavelengths for such a purpose and this constitutes one of the only ways in which to study the molecular chemistry within star-forming regions at very high redshift. These data will be combined with optical and near infrared afterglow spectroscopy, of intermediate resolution, obtained with the X-shooter spectrograph at the VLT, which mostly traces atomic gas, to produce an extensive study of interstellar medium. | Gamma Ray Bursts (GRB) | Cosmology | 2019-01-22T15:34:02.000 |
| 2591 | 2022.1.00905.S | 10 | The first characterization of the water snowline in a ringed protoplanetary disk | The water molecule plays a crucial role in the physics and chemistry of planet formation. In particular, the water snowline defines a specific region where dust grains drastically change their properties, promoting the formation of planets. The position of the snowline also defines the chemistry of the available planet building blocks. No direct imaging of the water snowline has been reported yet. With a resolution of 0.1, we will spatially resolve the water snowline in the HL Tau disk, where archival ALMA data show a robust detection of the Band 5 water line at 183.3 GHz. Motivated by this ground-breaking discovery, we will be able to directly connect the radial location of the snowline to the well-characterized grain distribution of this archetypal disk, a long-awaited constraint in any planet formation model. Additional data in Band 7 will further confirm the detection of the warmer water line at 325.1 GHz from the same archival data, opening a new window into the characterization of spatially resolved excitation studies of water vapour in disks. With this exciting discovery in hand, the time is ripe to fully exploit the ALMA potential on this new frontier in planet formation. | Disks around low-mass stars | Disks and planet formation | 2025-03-07T01:55:48.000 |
| 2592 | 2013.1.00014.S | 7 | How big is the AGN obscuring torus? | Unification of active galactic nuclei (AGN) is based on toroidal obscuration of the nuclear activity, which is powered by accretion onto a supermassive black hole. Understanding of the nature and origin of the obscuring torus requires reliable measurements of its size to determine whether it is within the gravitational sphere of influence of the black hole or of the galactic bulge. Thanks to its high spatial resolution and sensitivity to the thermal dust emission, only ALMA is capable of determining the torus end point. Here we propose observations of the archetypal Seyfert 2 galaxy NGC1068 in ALMA bands 7 and 9 to measure the radius of the obscuring torus and determine the radial profile of the toroidal cloud distribution. According to our radiative transfer calculations, these ALMA bands are within the wavelength range where the differences between continuous and clumpy torus models are maximized. Indeed, detailed simulations of the proposed observations show that by measuring the extent of continuum emission we will be able to assess the torus structure and distinguish between proposed models for the AGN torus. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-11-13T20:16:05.000 |
| 2593 | 2022.1.01056.S | 54 | Uncovering Embedded High-Mass Star-Formation Regions in the Metal-Poor Galaxy NGC 6822 | NCG 6822, a dwarf irregular galaxy, hosts some of the brightest and most massive known HII regions. Its proximity (490 kpc), low metallicity (0.2 solar), and lack of interacting companions make it an ideal target to study the impact of high-mass star formation on the physical conditions of the star-forming gas. We propose 2pc resolution CO(2-1) observations of three recently discovered embedded, massive star-forming regions in NGC 6822. These regions host the largest population of young stellar objects (YSO) in NGC 6822, and are the youngest and most active regions in this galaxy. With ALMA observations, we will: 1) characterize their molecular gas content for the first time, 2) combine our ALMA results with upcoming JWST and existing Spitzer observations of the massive YSO population to study the mutual impacts between environment and high-mass star formation, and 3) test if PAH emission is an effective tracer of molecular gas at low metallicity. Comparisons to observations of star-formation in the Magellanic Clouds will allow us to statistically study how environmental factors impact high-mass star formation, and how feedback from high-mass star formation shapes the environment. | High-mass star formation | ISM and star formation | 2023-10-12T23:32:34.000 |
| 2594 | 2022.1.00429.S | 6 | First subpc resolution imaging of the AGN-driven ionized outflow | Outflows from active galactic nuclei (AGNs) expel the surrounding gas and transport energy and matter to larger spatial scales. However, detailed outflow properties at the innermost subpc-scale, where the gas is largely ionized by the central AGN, remain unclear, due to limited spatial resolution and severe dust extinction at short wavelength observations (e.g., HST, VLT). To overcome these difficulties, we propose a novel technique to probe dust-obscured ionized gas properties: the use of submm recombination line (submm-RL). Indeed, we found pc-scale ionized gas outflows in the archival ALMA data of the H36a RL (135 GHz) measured toward the Circinus galaxy (type-2 AGN at 4.2 Mpc). However, limited resolution (0.06"*0.04") and sensitivity prohibited a detailed investigation of the outflow. Here we propose 0.036" (0.7 pc) resolution deeper follow-up observations of H36a. With this data, we can for the first time measure the outflow velocity, structural inhomogeneity, wind acceleration, distribution of velocity dispersion (shock), and mass outflow rate, all at subpc-scale in a spatially resolved manner. These must serve as milestone achievements for ALMA and the AGN community. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-08-16T02:59:06.000 |
| 2595 | 2015.1.01329.S | 36 | First resolved study of cloud-cloud collision at the edge of the Galactic center region | We propose to study for the first time at high spatial resolution, the cloud-cloud collision region at the edge of the central molecular zone (l~1.3-1.6 degrees). Previous works have shown that the molecular gas have two distinct velocity components, one associated with the X1-orbits and the other associated with the X2-orbits (in a barred potential model). These two components have different physical and chemical characteristics between each other: the gas following the X2 orbits has "normal" Galactic center properties (high densities and temperatures, expected chemical enrichment according to the chemical evolution model of the Galaxy), and the gas in the X1 orbits has a lower density, higher temperatures and a lower chemical enrichment (high 12C/13C isotopic ratio). This high spatial resolution mapping towards two representative regions will allow us to characterize all molecular clouds that are taking part in the cloud-cloud collision, identifying clouds purely associated with the X1- or X2-orbits. Since the barred potential model have been invoked as a suitable mechanism for gas accretion, this work is the key to understand the feeding of gas towards the Galactic center. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2017-05-04T13:29:06.000 |
| 2596 | 2012.1.00983.S | 8 | Probing the spatial distribution of star formation in distant ULIRG with ALMA | Using the deepest existing Herschel images of the GOODS-Herschel key project (PI D.Elbaz), we have found evidence that distant ultra-luminous infrared galaxies (ULIRGs) exhibit a wider range of properties than local ones suggesting that the physics involved in these distant highly star-forming systems is not limited to the major merger triggering of compact starbursts as it is locally. The finding of a tight scaling law linking the star-formation rate (SFR) of galaxies to their stellar mass up to z~3 or more suggests that instead it is extragalactic gas infall that regulates star-formation even in most of these systems. We have selected a sample of z~2 ULIRGs to probe the projected spatial distribution of star-formation in these galaxies spanning a range of "starburstiness" (excess SFR for their mass at their redshift) and Herschel vs Spitzer color index (IR8=L_IR/L_8um) - sensitive to the destructive power of concentrated massive stellar light on PAHs. Our goal is to not only determine typical sizes, but IR surface brightness and clumpiness, since distant ULIRGs are particularly irregular in shape. We will compare them to local ULIRGs, see if they fall on the same relations than those observed for local star-forming galaxies and compare their obscured vs rest-frame UV and optical light to spatially resolve optically thick star-forming regions and better understand the far-IR vs UV relation. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2015-10-24T18:15:32.000 |
| 2597 | 2019.2.00126.S | 31 | Can Isotopologue Line Ratios Probe the IMF in Extremely Star-Forming Galaxies? | We aim to trace molecular line ratios in multiple transitions in a sample of two nearby ULIRGs and one nearby post-merger galaxy. By observing 13CO and C18O (1-0) and (2-1) with the Atacama Compact Array (ACA), this program will determine if observered 13CO/C18O ratio values are due to optical depth effects, astrochemistry within the gas, and/or nucleosynthesis in stars. In particular, we will establish if an excess in C18O with respect to 13CO is conclusive evidence for a top-heavy stellar IMF in these extreme systems. | Starbursts, star formation | Active galaxies | 2022-11-10T20:11:05.000 |
| 2598 | 2012.1.00123.S | 3 | Probing the ionized envelope of Orion Source I | We propose to observe the high mass protostar Orion Source I at frequencies of 353 and 662 GHz to measure its continuum flux densities and to search for the H26$\alpha$ and H21$\alpha$ recombination lines in its spectrum. These observations -- about 1 hour per band -- will establish whether there is a source of Lyman continuum photons in this object, or whether instead the radio emission arises a massive disk that is heated largely by accretion. The Becklin-Neugebauer Object, another high mass star just $10''$ from SrcI, will be observed at the same frequencies as a calibration check. The SrcI/BN flux ratios, which are independent of the absolute calibration scale, may be used as benchmarks to monitor possible flux variations in SrcI in future years. | High-mass star formation | ISM and star formation | 2015-10-17T17:28:46.000 |
| 2599 | 2021.1.01133.S | 504 | An ALMA-FMOS-Webb Synergy at Galaxies' High Noon | We aim at promoting synergy between ALMA and JWST by acquiring dust continuum observations for a unique set of 57 massive star-forming galaxies at z~1.6 with secure spectroscopic redshift and measured metallicity from the Subaru/FMOS near-IR spectroscopic survey. The galaxies lie within the central 0.6 deg2 of the COSMOS field to be covered by the COSMOS-Webb Large Program on JWST that will provide deep multiband NIRCam and MIRI imaging, hence especially robust stellar masses. The proposed ALMA observations will allow us to obtain the complimentary dust mass of these galaxies and from it their cold gas content, taking advantage of the known metallicity in the dust mass to cold gas mass conversion. We plan to achieve rms=0.05 mJy to detect galaxies down to SFR~20 Msun/yr, corresponding to the lower envelope of the main sequence (MS) at ~10^11 Msun. We will measure the gas to stellar mass ratio of these galaxies and how it scales with the distance from the MS, hence elucidating whether deviations from the MS are primarily driven by the cold gas content or differences in star formation efficiency. The combined ALMA & COSMOS datasets will then further expand the unique COSMOS Legacy. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-12-26T20:12:02.000 |
| 2600 | 2021.1.00168.S | 83 | CO SLEDs of Hot DOGs at z~3 | The main objective of this proposal is to study the molecular gas properties of hot, dust-obscured galaxies (Hot DOGs) at z~3. These hyperluminous galaxies, discovered with the WISE satellite, are a rare class of galaxy characterised by their dominant hot dust components heated by a central obscured AGN. Far-infared spectral energy distributions of Hot DOGs indicate the presence of a luminous cold dust component, suggesting starburst activity. It has been proposed that Hot DOGs represent a transition between starburst- and AGN-dominated massive galaxies. Analysis of data from the ALMA archive yielded low-J CO detections of six Hot DOGs at z~3-4.6. Applying radiative transfer models to the proposed observations of CO(7-6) (along with [CI]), CO(9-8) (along with OH+) and CO(11-10) along with the source continuum will enable us to determine the temperature and density of the ISM in Hot DOGs, allowing us to differentiate between their AGN and star-forming components. High angular resolution observations of emission in these sources will allow size estimates and kinematics analyses in search of disturbed kinematics indicating the remnant of a major merger. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2022-11-28T04:31:42.000 |
| 2601 | 2023.1.00852.S | 0 | Understanding the Excitation of Molecular Gas in the Quasar-Starburst Systems at z>6 | The cold interstellar medium (ISM) in the quasar-starburst systems at high redshift is crucial for probing the early growth of the first super massive black holes (SMBHs) and their host galaxies. We propose an ALMA survey of the CO (9-8) line in nine quasars at 6.06 quasars will allow us to investigate the connections of the high-to-mid-J CO line ratio to the AGN luminosities and the local ISM properties including the dust SED/color/temperature, FIR luminosity, obscured column density, etc. Bright emission from very high-J CO transitions (J>9~17) was detected in several quasar host galaxies at z>6, suggesting contribution from AGN power in the gas excitation. Here we propose the first study to statistically explore the correlation between the CO excitation and the AGN power. The results will also motivate further observations of the full CO SLEDs for a larger sample and the detailed studies of ISM excitation mechanisms to understand the evolution of ISM in the young quasar host galaxies at the earliest epoch. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-11-19T13:23:09.000 |
| 2602 | 2024.1.00928.S | 0 | Dust, gas, and ice in edge-on disks with ALMA + JWST | Planets form from dust, gas, and ice within disks around young stars. Uniquely in disks with an edge-on viewing geometry, these three components can all be observed and even mapped to reveal their 2D (radial + vertical) distributions. Achieving this requires both ALMA and JWST. In the upcoming JWST cycle 3, 6 edge-on disks will be observed with unprecedented sensitivity-- but, there are few to no constraints on the gas and millimeter solids in these systems. This proposal aims to fill this gap with high-resolution (0.1-0.15"), sensitive observations of the continuum in ALMA Bands 1, 7, and 9, along with spectral line coverage of 13CO and C18O J=3-2. Together with the JWST data, this will open new windows on the planet-forming environment compared to what can be achieved by either facility independently: revealing the radial + vertical distributions of both the small and large grain populations; allowing for robust characterization of ice inventories and comparisons of the ice vs. gas reservoirs; and helping to constrain disk evolution theories. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 2603 | 2018.1.00814.S | 110 | Bridging the Mass gap - Disks around Intermediate mass protostars | We propose ALMA continuum and CO (2-1) band 6 observations to determine the bulk properties of disks around intermediate mass protostars (M>2.5 Msol) that we have previously studied with VLT X-Shooter. Specifically we will examine whether the viscous accretion scenario holds - where disk mass (the reservoir of material available) scales with accretion rate. ALMA will provide the disk masses, while we have accretion rates from our X-Shooter study. Our unique target list of 23 sources bridges the mass range between well studied T Tauri/Herbig Ae stars (<2Mo) and Massive Young Stellar Objects (>8Mo) and provides the first homogeneous sample of disks around sources in the unique mass range. We will also estabilsh the stellar masses directly from resolved CO obserations, which are required for RT models in order to correctly obtain disk temperature for calculations of the disk masses. Furthermore, we will examine the dust and gas disk sizes for evidence of discrepancies with the Rg/Rd = 2 from lower mass sources. Differences could provide insights into changes in radial dust transport and viscous spreading. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2020-11-29T23:15:33.000 |
| 2604 | 2017.1.00138.S | 32 | Wide ASPECS: Bridging the gap between targeted observations and molecular deep fields | Molecular gas investigations in distant galaxies typically focus on sources that have been pre-selected based on various properties, in particular stellar mass, star formation, or IR luminosity. By construction, these galaxies typically populate the bright end of the main sequence of star-forming galaxies. An alternative approach consists of sensitive observations of deep fields, where molecular gas emission is blindly searched for without any pre-selection. Again by construction, this latter strategy picks fainter galaxies than the ones identified by targeted observations, but in a well-defined cosmological volume. Here we propose to bridge the gap between these two approaches. With a 23hr Band 3 scan we will extend the deep field approach to an unprecedentedly large area (52.5 arcmin2, quintupling the area of the ASPECS Large Program). This dataset will pin down the bright end of the CO luminosity function at high redshift, and put the galaxies pre-selected based on ancillary data into the broader context of the underlying population of molecular gas emitters. Additionally, we will place the first direct constraints on the large-scale clustering properties of CO-bright gaalxies. | Galaxy structure & evolution | Galaxy evolution | 2019-10-26T09:07:43.000 |
| 2605 | 2019.1.00218.S | 3393 | A Serpens disk survey: exploring planet formation in an unexplored region | Protoplanetary disks are the birth cradles of planets. Several nearby star forming regions have been mapped by ALMA to derive disk masses which are fundamental for disk evolution studies, but the dense Serpens region with more than 1700 Young Stellar Objects has so far remained unexplored. Star forming regions with high stellar surface density such as Serpens are particularly interesting as dynamical interactions are expected to influence the protoplanetary disks and hence, their capabilities of forming planets. Heavy extinction in this region limits the identification of disks amongst younger objects in the IR, but ALMA is capable of identifying disks efficiently. We propose to observe 320 YSOs in the Serpens region in Band 6 continuum and 12CO 2-1 at ~0.25" resolution. Distances have been checked with Gaia DR2. The spatial extent and line profile will help to distinguish the disks from embedded objects and measure disk masses down to 1 Earth mass. The measurements of disk masses in Serpens will test the influence of dynamical encounters in dense regions and double the sample of derived disk masses in nearby star forming regions, required for statistical studies of disk evolution. | Disks around low-mass stars | Disks and planet formation | 2022-07-28T04:30:23.000 |
| 2606 | 2016.1.00839.S | 41 | WISDOM: supermassive black hole mass measurements for nearby spiral galaxies using molecular gas | Black holes are considered to play an important role in the galaxy evolution process, leading to various known correlations between the mass of the supermassive black hole (SMBH) and host galaxy properties (e.g., M-sigma relation, where sigma is the central velocity dispersion of stars). The correlations, however, are based on a relatively small number of measurements and a handful of methods with some limitations on sample selection. Recent works on dynamical SMBH mass measurements using molecular gas kinematics, including our published works and preliminary results, open a possiblity to increase the number and variety of galaxies with their SMBH masses measured with great accuracy. ALMA Cycle 4 enables one to measure SMBH mass in a number of nearby galaxies by utilizing extended array configuration. We propose to observe 4 spiral galaxies distributing in the M-sigma plane yet to be explored with our method. The data will allow us to weigh SMBHs using molecular gas across the M-sigma relation, and will add some late-type galaxies to balance the currently biased sample. | Galactic centres/nuclei | Active galaxies | 2018-03-22T16:32:29.000 |
| 2607 | 2017.1.00337.S | 44 | Metallicity of GRB Host Galaxies Based on Redshifted Far-IR Fine-Structure Lines | We propose ALMA observations of dust-obscured star-forming galaxies at z=1-2 in which Gamma-Ray Bursts (GRBs) occurred to investigate their metallicity environments by using far-IR fine-structure lines. This kind of host galaxy is a missing population due to the strong dust extinction in optical. In previous works, the metallicity measurements of such dusty host galaxies have been conducted only for a small fraction. They are distributed in high-metallicity end of GRB host galaxies in contrast to the low-metallicity requirement by widely accepted theoretical simulations of GRB progenitors. This may suggest a stellar evolutionary channel of GRBs which does not require a low-metallicity environment such as a binary-star interaction. However, the optical emission-line diagnostics have distinct limitations in investigating such dusty galaxies. We here focus on the [NII]205um/[CII]158um ratio which is a good metallicity indicator available for optically faint dusty galaxies. Only ALMA can offer an innovative new method to approach to the origin of the missing population, i.e., dust-obscured GRBs, alternative to the previously used optical diagnostics. | Gamma Ray Bursts (GRB) | Cosmology | 2019-05-30T23:47:39.000 |
| 2608 | 2017.1.00526.S | 119 | Where and when do low-mass stars form in high-mass protoclusters? | While formation of high-mass stars in clusters has been intensively studied, where and when low-(and intermediate-)mass stars in clusters form is still unclear. Existing ALMA observations toward two protoclusters at different evolutionary phases suggest different formation paths of low-mass cores where low-mass star formation takes place. Whether this discrepency is environment-dependent or evolution-dependent is unknown because of the small sample size so far. To resolve the spatial distribution of low-mass cores in protoclusters and trace their evolution as clusters form, we propose to observe 8 protoclusters in a variety of evolutionary phases, from prestellar to HII regions, with ALMA at band 6. We will find out whether low-mass cores in protoclusters preferably locate immediately around high-mass cores or uniformly distributed, and whether they form at the same time or after the high-mass members in clusters. | High-mass star formation, Low-mass star formation | ISM and star formation | 2020-07-27T00:00:00.000 |
| 2609 | 2017.1.01607.S | 37 | Multi-wavelength imaging of the possibly planet-induced asymmetries in a pre-transitional disc | Scattered-light imaging of several transitional discs revealed intriguing spiral-arm structures that might be tell-tale signs of planet formation. However, it is not clear whether these structures correspond to significant surface density enhancements, or whether they are minor surface scale-height perturbations. Here we propose Band 7 observations on the pre-transitional disc of V1247Ori, where our recent SEEDS polarimetric imaging revealed an one-armed spiral-arm structure on scales of 200-300mas. As follow-up observations of our Cycle 3 project, our ALMA imaging aims to (a) determine the azimuthal density-contrast in dust continuum, (b) search for streamers and emission from the putative planet, (c) trace gas spatial distribution and kinematics, and (d) search for variations in the gas-to-dust mass ratio. | Disks around low-mass stars | Disks and planet formation | 2019-02-02T08:06:13.000 |
| 2610 | 2017.1.01647.S | 55 | High resolution ALMA imaging of gas and dust in low-z gas rich galaxies (resubmission) | One of the most striking differences between the nearby and high-z star-formation activity is the presence of giant molecular clumps in gas-rich disk-galaxies which can be as 100-1000x more massive than those seen locally. Is it therefore crucial to understand the dynamical processes that give birth to those high-z gas-rich and highly turbulent disks. From our previous experiments, we have identified three gas-rich galaxies, f_gas=MH2/(MH2+Mstar)>0.3 at z~0.1-0.2, which could be perfect laboratories to understand the star-forming physics seen in gas rich galaxies at z>1. As a follow-up campaign, we propose to target these three bright, gas-rich galaxies to resolve at 0.2" resolution (sub-kpc-scale rest-frame) the detailed spatial distribution of the 850 micron dust continuum and 12CO(3-2) line, in order to examine the dynamics of these recently discovered galaxies at z~0.1-0.2. At the exquisite signal-to-noise provided by their nearby nature, we can put tight constraints on the internal properties of these galaxies, including Larson's relations, the Kennicutt-Schimdt law and the L850-MH2 calibration for the different molecular gas regions. Resubmission of proposal 2016.1.01540.S. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2019-10-08T22:41:38.000 |
| 2611 | 2016.1.00102.S | 20 | Revealing the Nature of Counterparts of Sources selected from the LABOCA survey on the Spiderweb Protocluster Field | Our submm imaging with APEX LABOCA at 870micron has uncovered an overdensity of dusty star-forming galaxies related to the protocluster field of the radio galaxy MRC1138-262 at z=2.16 (ESO Press Release October 2014). We propose ALMA 870micron snapshot dust continuum imaging of 13 LABOCA sources (<1hr). Conducting these confusion-free observations will bridge the gap between our low resolution LABOCA far-infrared imaging and the outstanding subarcsecond accurate optical/NIR dataset (VLT, Subaru, HST) we have obtained in the past 15 years on this field. Only the ALMA data will allow us to confirm the reliability of these sources, identify unambigioulsy the optical/NIR counterpart and confirm cluster membership. This confusion-free 870micron data will enable us to measure the morphology of these SMGs and reveal multiplicities. Having this information in hand will enable us to characterize accurately their properties such as the star formation rate, stellar, molecular gas masse, gas depletion time scale and star formation efficiency, all dependent on environmental effects in high-density fields. The results will be compared with the ALMA+LABOCA blank field reference survcey ALESS. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-01-24T06:00:41.000 |
| 2612 | 2022.1.00423.S | 21 | Infalling filamentary streamers in an isolated low-mass protostar: dominant or secondary mass transporter? | Gravitational collapse is one of the main processes in star formation. While hydrodynamical simulations often show filamentary structures with mass flowing from cores to protostars, observational evidence of such infalling filaments (so-called streamers) had been elusive until recently, when a few studies discovered large-scale (>1000 au) filaments with kinematics consistent with simple infall models. Due to the scarcity of known sources with streamers, our understanding of their role in collapsing envelope remains unclear. We propose to unveil the kinematics of three filaments around BHR 71, which have been identified from archival HCO+ and HC3N data. The HCO+ filaments extend to ~1000 au, while the archival HC3N observations hint at larger scale (~2,000 au) streamers. BHR 71 IRS 1 is an ideal source to characterize the streamers due to its isolated nature and well-constrained model of its collapsing envelope. If the filaments are indeed infalling flows, BHR 71 would be the second source known to have multiple streamers and become a testbed of infall models. | Low-mass star formation | ISM and star formation | 2024-06-08T08:22:44.000 |
| 2613 | 2023.1.00642.S | 0 | A Quest for the Acceleration Mechanisms of Cosmic Rays in the Clumpy ISM | The interaction between the supernova shocks and the clumpy ISM has received much attention as an efficient acceleration mechanism of cosmic rays. We propose ALMA CO observations toward the supernova remnant (SNR) HESS J1731-347 to reveal how the clumpy ISM affects the acceleration mechanisms of cosmic rays and their non-thermal radiation. HESS J1731-347 is the best laboratory to test the effect because of its bright synchrotron X-rays and the presence of shocked clumpy ISM. Most recently, we have revealed X-ray limb-brightening around the shocked clumps using archival CO datasets taken by a single-dish telescope, suggesting that the magnetic field amplification and efficient acceleration of cosmic-ray electrons possibly occurred. However, the modest resolution of 40'' (or ~1 pc) for the current CO data could not evaluate a relation with the X-ray properties quantitatively. The proposed ALMA ACA observations of CO(J=2-1) at a resolution of 5.4'' (or ~0.14 pc) will allow us to compare the clumpy ISM with cosmic-ray-induced non-thermal radiation. This is the first important step beyond the classical theory of particle acceleration assuming the uniform ISM. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-03-26T09:39:05.000 |
| 2614 | 2019.A.00038.T | 5 | The size and albedo of exceptional comet C/2014 UN271 (Bernadinelli-Bernstein) | Comet C/2014 UN271 (Bernadinelli-Bernstein) was discovered in 2014 at about 29 AU from the Sun by the Dark Energy Survey. According to the latest orbit solution, based on all the astrometry available so far from 2014 to June 2021, its aphelion would be located at around ~50000 au, meaning that this object originates from the inner part of the Oort Cloud. Its perihelion will occur (in 2031) at 10.95 au, just beyond the orbit of Saturn. Observations in the last few days (June 21-23, 2021) have revealed the object to be active at 20.2 au from the Sun. Only super-volatile species (e.g. CO, N2) can explain activity at such distance. The estimated nucleus size is in the 100-200 km range. Hence comet C/2014 UN271 is exceptional from the combination of its orbit and large size. We aim to measure the thermal emission from the nucleus to determine the size and albedo of the nucleus via the radiometric technique. We will also constrain the large particle properties in the coma. These observations should be done in extended configuration (C8-C10), as soon as possible to minimize contribution due to possible large dust particles. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2022-02-19T07:58:11.000 |
| 2615 | 2017.1.00541.S | 46 | The less-biased star forming nature and early co-evolutionary relations in low-luminosity quasars at z > 6 | Previous studies of the properties of galaxies hosting quasar nuclei and their possible co-evolution at high-z were strongly biased towards very luminous objects, that prevents us from understanding the general picture of the growth of supermassive black holes (SMBHs) in the early universe. With this in mind, we have been conducting multi-wavelengths follow-up campaigns of our recently identified low-luminosity quasars at z > 6, which are >10 times fainter than previous samples of luminous z~6-7 quasars. In cycle 4, we found that the hosts of those low-luminosity quasars have star formation properties (dust mass, SFR) similar to local LIRGs, which are quite different from those of galaxies hosting luminous quasars. With this ~7 hr program, we aim at detecting the [CII] line and the underlying FIR continuum emission of three mroe of our low-luminosity quasars to confirm the LIRG-like trend obtained in cycle 4. The star forming nature as well as [CII] velocity dispersion will let us investigate the co-evolutionary relationship (we will obtain information on black hole mass from time-allocated NIR spectroscopy) at the early universe in a less-biased way. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2019-03-29T20:24:21.000 |
| 2616 | 2019.1.01317.S | 37 | The excitation mechanism of spinning dust emission in NGC 2023 | The anomalous microwave emission (AME) is a dust-correlated emission mechanism that is observed between 10--100 GHz. It is thought to originate by electric dipole emission from dust grains spinning at GHz frequencies. We have detected AME at arcsec angular resolution with the VLA at 28 GHz that correlates strongly with emission from Polycyclic aromatic hydrocarbons (PAHs) in the photo-dissociation region (PDR) NGC 2023. Within the spinning dust (SD) model, interactions with plasma and ions are expected to be the dominant rotational excitation mechanism in PDRs. To test this hypothesis, we propose to map HCO+ and HCN emission from NGC 2023. These lines are associated with the strongly irradiated surface of the PDR, so we expect a correlation with the peak of the SD emission. Additionally, we propose to observe deeply two pointings within the cloud that show the largest spinning dust emission at 28 GHz with the idea of measuring H13CO+ and HOC+. These lines can be used to measure the ionization fraction and model the physical conditions across the PDR. This will allow us to find the physical conditions that give rise to the spinning dust emission. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2021-03-02T16:42:27.000 |
| 2617 | 2021.1.01195.S | 46 | Do "dense gas tracers" really trace dense gas? | Molecules with high critical densities such as HCN and HCO+ have been used as tracers of dense molecular gas. Recently a number of large-scale observations in Galactic molecular clouds showed that these "dense gas tracers" emit not only from dense, star-forming cores, but also from more extended, diffuse regions. Alterntively, N2H+ is shown to have more compact emission, likely tracing true dense gas (n > 10,000 cm-3). Some extragalactic observations have started to show difference in emission between HCN and N2H+. It is urgently needed that we understand the nature of traditional dense gas tracers such as HCN and HCO+, as well as N2H+ in order to have correct interpretation of dense-gas studies in external galaxies. Here we propose mapping observations of M83 with HCN and N2H+, which will cover a large number of GMCs. For an independent measure of mass in the GMC, we will also request dust continuum observations in this field. This will be the first survey of N2H+ in extragalactic sources, and can significantly deepen our understanding of dense gas tracers. | Galaxy chemistry, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2023-07-08T08:51:53.000 |
| 2618 | 2019.2.00190.S | 18 | Formation of VLM stars and BD in Lambda Orionis Star Forming Region (LOSFR). ACA view of LDN1589 | For over 10 years, our group has led an ambitious multi-wavelength project to study key aspects of stellar and substellar formation in the LOSFR. For the central cluster, we determined the membership, IMF, and constrained possible substellar formation mechanisms, activity, accretion, disk fractions. One of its dark clouds, B30, has been observed from optical to radio; we studied the earliest stages of substellar objects as well as the radio data. ALMA Band 7 data allowed us to detect 3 very low-mass compact sources. With this proposal we focus on one of the youngest dark clouds of the LOSFR, LND1589, for which we have archival data from the optical to the mid-infrared, and submm data taken by our group at 870um using APEX/LABOCA. We propose ACA Band 6 observations (along with our APEX project) to: i) obtain spectral index information on sources detected in both projects, ii) improve our selection function to identify candidates to be followed up with the 12m array, iii) build a larger poll of pre/proto-substellar objects to put strong constraints on the proposed formation mechanisms. | Low-mass star formation | ISM and star formation | 2022-08-23T22:56:38.000 |
| 2619 | 2017.1.00079.S | 349 | Mapping Molecular ISM in the Whole Disk of M83 | We propose a full mapping of the cold molecular gas over the whole disk of M83 in CO(1-0) using ALMA 12m+7m+TP. This closest (d=4.5Mpc) face-on (i<30deg) archetypical barred spiral galaxy closely resembles our own Milky Way, and has been the important showcase for multi-wavelength studies. The proposed ALMA CO(1-0) map will not only detect the smallest clouds at the lowest end of the cloud mass function (10^4Msun), but also reveal the more extended, ambient molecular gas outside GMCs. This full census of the molecular ISM will be correlated with galactic environments and star formation, from the molecule-dominated galactic center to the atom-dominated outskirts, across the bar, spiral arms, and interarm regions. In combination with the ALMA CO(2-1) map (Cycle 4), we will use the CO 2-1/1-0 ratios of all GMCs to diagnose their physical states and variations as a function of the environments. We will also test the paradigm of GMCs as physical entities by measuring the partition between GMCs and the ambient molecular gas. The ALMA CO(1-0) map will become the foundation for future ALMA studies at higher resolution and in other molecular lines. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2020-01-10T00:00:00.000 |
| 2620 | 2015.1.01129.S | 16 | Molecular clumps in a star-forming galaxy at z~1.4 | We propose CO(2-1) observations of a main-sequence star-forming galaxy at z~1.4, which has several molecular gas clumps in CO(5-4) emission line. Size, molecular gas mass, and velocity width of each clump are estimated to be ~4 kpc or less, ~ 50 km/s, and ~5 x 10^9 Msun, respectively, though the clump sizes are not well constrained. The clumps are considered to be important blocks to build a disk galaxy, particularly bulge. Nevertheless, presence and nature of the molecular gas clumps is not yet well known at high redshifts. Thus unveiling properties of the molecular clumps is inevitable to understand disk galaxy evolution. Since we have CO(5-4) data taken with ALMA, by combining the data, we can derive gas density and size of each clump and test whether the clumps formed via gravitational disk instability. Since CO observations of molecular clumps in a wide range of star-forming galaxies at high redshifts is still hard with ALMA, our case study will give us useful insights on formation and evolution of molecular clumps and relation to the clumps seen in other wavelengths. | Galaxy structure & evolution | Galaxy evolution | 2018-07-19T06:32:34.000 |
| 2621 | 2017.1.01261.S | 31 | How Hierarchical is Cluster Formation? The Case of G11.92-0.61 | Most stars form in clusters and associations, yet basic aspects of how this occurs remain unknown. Hierarchical and monolithic cluster formation models make opposite predictions for the spatial extent of the protostellar members of a forming protocluster, while individual hierarchical models differ in their predictions for the relative birth order and spatial distribution of high- and low-mass protostars. We will distinguish between these models by searching for the low-mass protostellar population within the deeply embedded massive protocluster G11.92-0.61. With matched-resolution (675 AU) mosaics at 1.0mm and 1.3mm, we increase the mapped area by 3x and improve the mass sensitivity by 5x compared to our Cycle 2 observations, which revealed 16 new low-mass cores within radius<0.33 pc of the central massive protostars. By imaging the full extent of the gas reservoir (920 Msun) at two wavelengths, we will characterize the protostellar population down to a circumstellar gas mass of 0.03 Msun, measuring their emission mechanisms (via spectral indices) and velocities. To gauge their accretion activity, we target multiple outflow tracers spanning a range in abundance and excitation. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2020-03-18T00:00:00.000 |
| 2622 | 2013.1.01215.S | 15 | Small scale structure of the IRC+10216 CS shells, a key to the mass loss process and chemistry | IRC+10216/CW Leo, the closest high mass-loss star, is the best place to investigate the mass loss from TP AGB stars, a key, poorly known process that provides 3/4 of the matter recycled by stars. It is surrounded by an extended spherical envelope expanding at 14.5 km/s. Large angular size, uniform expansion and rich chemistry makes it a readable record of mass loss history and an unique probe of time-dependant chemistry. The envelope has been fully mapped in the CO(2-1) line emission, the best single tracer of the molecular gas, with the SMA and the IRAM 30-m single dish telescope. The resulting map shows a series of nearly concentric shells resulting from mass loss events separated by 800 yr. However, the limited dynamics of the SMA observations precludes the study of CO emission at radii closer than 30" from the star (i.e. during the last 1600 yr), a region dominated by very strong emission from the star. The inner region is of key importance for understanding the mass loss mechanism. We propose to map with ALMA its CO(2-1) emission at a resolution of 0.2" (10 yr). Adjacent lines of the key chemical species CN, CS, 30SiS, C4H and H13CC2N will be observed simultaneously. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2016-12-09T19:23:54.000 |
| 2623 | 2015.1.00716.S | 10 | High angular resolution search for signs of planets in a dynamically active debris disk with ALMA | Studies of young debris disks can insight the currently unconstrained process of planetary formation. Young stars which still retain debris disk can potentially provide valuable clues to the formation and evolution of newly formed planetary systems. We identified a particularly interesting young debris disk around an A type star in our database of 301 debris disks. Some of its basic properties (radius of the disk at the stellar age) cannot be explained solely by a steady-state evolution. This suggests that the disk is not self-stirred but that more massive bodies may stir the planetesimals in the disk. This diagnostic, based on contemporary numerical simulations, could be a smoking gun for the presence of one or more giant planets around these stars. We propose to test this hypothesis with Band 6 ALMA observations. With spatially resolved observations of the debris disk, we will constrain the large-scale geometry of the disk, better constrain the stirring mechanism, search for signatures of planet-disk interactions and possibly constrain the presence of gas and discuss its origin (primordial or of second generation). | Debris disks | Disks and planet formation | 2017-07-29T15:21:17.000 |
| 2624 | 2016.1.00691.S | 268 | Thermal Properties of Icy Satellites | Geological activity and subsurface oceans are widespread on icy bodies in our Solar System. The Galilean satellites Callisto, Ganymede, and Europa are three such worlds, whose diversity of surface properties provide clues into their different thermal and geological histories. We propose to map the continuum emission from both hemispheres of all three satellites at high spatial resolution, at frequencies of 100, 230, and 345 GHz, which probe ~cm depths in their subsurfaces. Such maps will allow us to determine the thermal surface properties, and will give insight into the origin of large-scale hemispheric differences. | Solar system - Planetary surfaces | Solar system | 2018-10-12T06:17:30.000 |
| 2625 | 2013.1.00070.S | 16 | A survey of carbon-rich circumstellar envelopes | To date, most of our knowledge on circumstellar chemistry of carbon-rich envelopes is based on the results obtained towards a single object, IRC+10216. In order to obtain a more general knowledge of the chemistry in these envelopes we intend to use ALMA to perform a spectral line survey in the 3 mm band of a sample of carbon stars including IRAS07454-7112, IRAS15082-4808, IRAS15194-5115 and AFGL3068. Single dish spectral line surveys in the 3mm band have been performed of all stars in the sample. The physical characteristics of the envelopes are similar, but there are more than an order of magnitude variation in abundances of some species such as SiO, SiC2, C4H, and C3H2 (Woods et al. 1993). The abundance calculations in Woods et al., however, suffered from the assumption that the emitting regions had the same morphology and size as in IRC+10216. To determine accurate molecular abundances, we need the spatial information of the emitting regions in the objects in the sample. The ALMA data will be used as input for models developed by members of the team to determine the physical characteristics and chemistry of the circumstellar envelopes of the objects in our sample. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2017-01-06T00:00:00.000 |
| 2626 | 2015.1.00540.S | 6 | How dusty are the brightest z ~ 7 galaxies? | The prevalence of dust in z > 6 galaxies remains controversial, with the current observations implying obscured-to-unobscured luminosity fractions (Lir/Luv = IRX) that span several orders of magnitude. The goal of this proposal therefore is to obtain 1.2mm dust continuum observations of the first complete, magnitude limited, sample of the brightest known z ~ 7 galaxies. These galaxies are unique at z > 6 in that they are massive [log(M/Msun) ~ 10], highly star-forming [Muv < -22, SFR = 10-100 Msun/yr], and recent Cycle 22 HST/WFC3 imaging has revealed evidence for merging/interactions. In ~10 minutes of integration per object with ALMA, we will strongly constrain the IRX of the most vigourously star-forming galaxies at z ~ 7, which are expected (both theoretically and from lower redshift observations) to be the most obscured. The results will be crucial for quantifying the importance of dust obscuration in shaping the bright-end of the rest-frame UV luminosity function at z ~ 7, where theoretical models currently require significant dust to already be in place. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2017-02-17T19:54:09.000 |
| 2627 | 2016.1.00293.S | 65 | Bridging the gap between optical and infrared galaxy populations: Localizing AzTEC/LMT sources in the Frontier Fields | In order to complete the census of cosmic star formation, we need to bridge the gap between infrared/submillimeter and optical/UV-selected galaxy populations at high redshift. Targeted observations of the dust continuum with ALMA is leading to a confusing and biased picture of the role of dust obscured star formation at high redshift. Our new AzTEC/LMT 1.1mm survey of the HST Frontier Fields reaches down to the fluxes expected from these optical/UV populations, but our exploitation of these sources is limited by the 8.5 arcsec beam. Following the approach of the successful ALESS survey, but pushing to much lower intrinsic fluxes, we propose to localize the millimeter emission in all AzTEC/LMT sources in two of the Frontier Fields in order to make unambiguous associations with the optical galaxies in the deep HST images. Armed with the single-dish millimeter flux, this is a low risk, inexpensive project which will result in a faint flux-limited sample of galaxies with accurate measures of both the obscured and unobscured star formation. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-04-28T23:08:25.000 |
| 2628 | 2022.1.00834.S | 6 | The Jet Motion and Time Variability in a Massive Proto-binary | Recent theoretical studies suggested that disk accretion is the key to circumventing feedback in very massive stars. Collimated jets provide us the guidepost of ongoing disk accretion in the vicinities of forming massive stars. We propose a new high-resolution 3mm imaging of IRAS16547-4247, the O-type proto-binary system associated with a collimated jet. Comparing the result with the previous epoch image taken in 2019, we will search for the proper motions and the time variabilities of the two massive protostars and the jet knots. With the 0.045" resolution, we can detect a proper motion with ~200km/s by one-beam size. Tracing back the 0.3pc-long jet knots, we will discuss the disk orientation variability, testing the precession scenario. We will also investigate the variabilities of accretion onto the two protostars based on their flux fluctuations. The proposed observation will test the disk accretion scenario in massive star formation and demonstrate the high-resolution ALMA capability for the time-domain science. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2024-08-23T03:06:18.000 |
| 2629 | 2017.1.00470.S | 67 | Morphology of Polarization in T Tauri Stars: What the Flux? | Polarized dust emission from circumstellar disks is turning out to be more complicated and more interesting than we previously thought. Recent HL Tau circumstellar disk polarization results suggest that there are three mechanisms for producing polarized dust emission at millimeter wavelengths in disks: dust aligned by magnetic fields, dust aligned by local radiation anisotropy, and light scattered from the disk itself. Instead of making polarization less important, dust continuum polarization in circumstellar disks is evolving into a new tool, with proper modeling, that can be used to characterize the magnetic field, dust grain properties, and the radiation field of the circumstellar disk. However to assess the importance of these techniques, a small, resolved sample of the next brightest disks are essential. In this proposal, we use dual-wavelength observations (870 microns and 3 mm) as a long lever arm to probe the contributions from the three mechanisms and characterize the disks and their environment. | Disks around low-mass stars | Disks and planet formation | 2019-03-30T01:22:12.000 |
| 2630 | 2011.0.00524.S | 0 | Resolving the massive molecular outflow G331.5 | We propose to spatially resolve and to determine the gas density and temperature for a high-velocity molecular outflow in the multiple massive star forming region G331.5-0.1. This is the core of a GMC at a distance of 7.5 kpc, in the tangent of Norma spiral arm, a counterpart to the northern W43 GMC but in the peak of the southern molecular ring. The outflow is among the most massive and energetic discovered so far (flow mass 55 Mo , momentum 2.4 e3 Mo km/s and kinetic energy 1.4 e48 ergs). The region contains 6 massive dust concentrations, mapped in the mm continuum with SIMBA and LABOCA, with a total luminosity of 3.6 e6 Lo, about 10 times larger than the typical value for massive star forming regions in the Galactic disk. The outflow was discovered and preliminary characterized through APEX and ASTE molecular line observations. The proposed ALMA observations will permit to spatially resolve the outflow; the SiO at different frequencies will allow to determine rotational temperatures and densities for the outflow; and the H13CO+ lines will yield the properties of the ambient gas. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2013-06-01T15:25:00.000 |
| 2631 | 2022.1.00016.S | 82 | High-Resolution Imaging of Deuterated Methanol (CH2DOH) in Orion KL: Toward Resolving a 30-Year Mystery | The relative abundances of deuterated methanol ([CH2DOH]/[CH3OD]) in star-forming regions deviates from the statistically expected ratio of 3. In Orion KL, the observed ratio is about 1. Why Orion KL and other massive star-forming regions harbor three times as much CH3OD (relative to CH2DOH) than expected has been asked for three decades. Surface and gas-phase chemical processes have been considered, with D-H exchange between solid water and methanol on ices being the favored explanation. High-resolution Cycle 5 observations of Orion KL support D-H exchange and reveal a temperature-dependent chemistry. We propose complementary CH2DOH observations to test how [CH2DOH]/[CH3OD] varies across the nebula. Using pixel-by-pixel spectral line fitting of the obtained data cubes, we will compare CH3OD and CH2DOH column density maps and assess how environment (e.g., gas temperature, proximity to protostellar cores) affects [CH2DOH]/[CH3OD]. The proposed observations will help resolve a 30-year observational mystery surrounding deuterated methanol and provide critical chemical insight to guide future experimental and theoretical work needed to contextualize observations. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-12-29T22:28:58.000 |
| 2632 | 2023.1.00158.S | 0 | Planet formation in extreme environments: proving the ubiquity of disk substructures in the substellar regime | Disks around Brown dwarfs constitute excellent laboratories to test planet formation in extreme environments and the ubiquity of planetary systems. The source 2MASS J04442713+2512164 is the best candidate to study planet formation and circumstellar disk structures in the substellar regime, hosting one of the brightest and largest disks resolved in the submillimeter by ALMA. It shows evidence of grain growth and a SED that is better reproduced by a disk with an inner dust gap, pointing to the presence of substructure(s) within the disk. Dust evolution models can reproduce grain growth in this source with the existence of multiple pressure bumps or a bigger inner bump due to a giant planet. We propose to observe the disk in band 7 at a resolution of 0.045 (6 AU at 140 pc) to resolve its radial distribution of dust and study the presence of disk substructures in the substellar regime. Our study will provide critical data to test the dust evolution models and planet formation theories in brown dwarf disks for the first time. | Disks around low-mass stars | Disks and planet formation | 2025-02-14T23:23:09.000 |
| 2633 | 2019.1.00743.S | 180 | Investigating CO-Dark Molecular Gas through Synergetic Centimeter and Millimeter Absorption observations | The common, familiar tracer for molecular hydrogen (H2) is CO emission. However, H2 without CO emission, called "Dark Molecular Gas", turns out to be surprisingly abundant, roughly equal in mass to the more familiar CO-traced H2. Dark Molecular Gas represents the transition between the atomic ISM to the molecule-dominated ISM -- the initial stage of star formation, which lies at the very heart of modern astrophysics. To explore the conditions that lead to this transition, we propose a broad frontal attack on dark molecular gas with absorptions in both 3 mm (with ALMA telescope) and 21 cm (with VLA telescope). In this proposal, we propose to use ALMA to survey the J=1-0 lines of HCO+ and CO and HCN, HNC, and CN lines against 10 quasars toward dark gas regions we derived from analyzing gamma ray surveys. These quasars are strong in both 3mm (S>0.5 Jy) and 21cm (S>1.0). In absorption, ALMA can accomplish in minutes what requires hours at CARMA, making such a systematic study feasible. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-02-22T16:20:34.000 |
| 2634 | 2013.1.00187.S | 12 | A Survey of Ophiuchus and Orion B North | Recent interferometric surveys of starless cores have found that 1) 5-20% of these objects actually harbor low-luminosity star-forming objects, and 2) none of the truly starless cores have any detectable substrucure or evidence for fragmentation. These surveys, however, were intentionally biased and suffer from small sample sizes. To begin to address this problem, we have an approved (highest priority) ALMA Cycle 1 survey of all starless and protostellar cores in the Chamaeleon I molecular cloud, a region of low-mass and isolated star formation. Here we propose to carry out a similar survey of all known cores in the Ophiuchus and Orion B North moelcular clouds, the nearest star-forming regions with very different physical conditions than Chamaeleon I. This survey will enable the first accurate, uniform, and high resolution census of dense cores in a range of environments. We will determine definitive classifications (starless or protostellar) and discriminate between models of star formation that predict different paths for the origin of binary protostellar systems. We will test the extent to which the environment in different clouds influences the path(s) of star formation. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-03-30T14:03:59.000 |
| 2635 | 2017.1.01649.S | 38 | Using the Sunyaev-Zel'dovich effect to probe morphological disturbance in a high-z galaxy cluster | We whish to make follow-up ALMA 12m observations in B3 and B4 at the BCG position of the high redshift cluster SPT-CL 2106-5844 (z = 1.13) to probe the cluster core region in SZ after point source removal using the ALMA 12m baselines. This will complement our ACA B3/B4 detection of project 2016.1.01175.S. | Galaxy Clusters | Cosmology | 2019-06-10T17:12:29.000 |
| 2636 | 2017.1.01078.S | 28 | Doubling the Number of Class 0 and I Disks Through ALMA Line Observations of Perseus Disk Candidates | Disks play a pivotal role in the formation of stars and planets. Nevertheless, disks are poorly characterized in the earliest phase of the star formation process (i.e., the Class 0 phase). We propose ALMA observations of molecular lines (e.g., C18O) toward 11 single protostellar disk candidates discovered in an unbiased VLA 8 mm survey of all protostars in the Perseus cloud. The molecular line observations will determine whether or not the resolved, disk-like structures discovered at 8 mm are consistent with Keplerian rotational support. We will also determine if emission associated with the disk is indeed more radially extensive at 1.3 mm than 8 mm as seen in other sources. These observations are essential to the interpretation of our VLA continuum data. We cannot fully understand the nature of these resolved structures without knowledge of their kinematics. The proposed sample has the potential to more than double the number of known Keplerian Class 0 protostellar disks. Thus, these observations have the potential to significantly improve our evolving understanding of disks in the protostellar phase and the rate of protostellar mass build-up during the star formation process. | Low-mass star formation | ISM and star formation | 2019-10-26T16:30:40.000 |
| 2637 | 2013.1.01364.S | 4 | Molecular gas in a galaxy's wake | We propose a large-field CO(1-0) ALMA mosaic of the Norma cluster galaxy ESO 137-001, which is an excellent candidate for transformation from a blue to a gas-poor type due to a violent removal of its ISM by ram pressure stripping. It sports the most dramatic X-ray tail of a late-type galaxy ever observed, presumably originating from mixing of cold stripped ISM with the surrounding hot intracluster medium. It extends to a distance of 80 kpc, and is accompanied by a shorter and broader tail of numerous HII regions. APEX observations revealed a bulk of cold gas to a large distance of 40 kpc downstream in the tail, indicating for the first time that molecular gas may form in-situ in the stripped gas. We wish to map molecular counterparts to the multiwavelength tails and determine their distribution, structure, and kinematics. The competing effects of heating and cooling on the stripped ISM, star formation efficiency along the tails, and the amount of turbulent motions in the cold gas will be studied. ESO 137-001 is the best candidate for detailed studies of the effects of strong ram pressure on galaxy transformation. This proposal will generate a spectacular ALMA image. | Merging and interacting galaxies, Galaxy groups and clusters | Galaxy evolution | 2016-07-14T10:56:08.000 |
| 2638 | 2015.1.00150.S | 21 | The First Detection of the Glycine Precursor Hydroxylamine (NH2OH) in the Interstellar Medium | The aim of this project is the first detection of hydroxylamine (NH2OH) in the interstellar medium. NH2OH is an important precursor in space for the formation of amino acids - the building blocks of life. Abundances within reach of ALMA are predicted from recent laboratory experiments in our group that have focused on the solid-state chemistry of nitrogen oxides in interstellar ice analogs. Our results show that for low temperatures, NO and NO2 ices are readily converted into NH2OH upon sequential hydrogenation, yielding a stable end-product. In warmer environments, NH2OH can thermally desorb, yielding detectable gas-phase abundances, while in shocked regions, the solid NH2OH can be liberated en masse into the gas phase. Only ALMA has the sensitivity necessary to identify this important species. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-05-20T00:26:37.000 |
| 2639 | 2012.1.00208.S | 0 | The Lowest Metallicity Molecular Clouds | Stars form out of molecular clouds, dense concentrations of gas that are traditionally traced in external galaxies using transitions of CO. However, the structure of molecular clouds at low metallicities may be fundamentally different compared to that found in higher metallicity spirals. In particular, the CO core in a typical cloud is expected to shrink and the photo-dissociation region (PDR) grow with decreasing metallicity. This potentially has profound affects on the star formation process. We propose to map 12CO 1-0 in two regions of the low metallicity dwarf galaxy WLM where we have 12CO 3-2 detections with the single-dish APEX-2 telescope. These will be the lowest metallicity clouds ever mapped at this detail (by a factor of 1.6). With the ALMA data, coupled with our Herschel PDR fine-structure line maps, we will determine the structure of the molecular cloud to test the theoretical prediction on molecular cloud differences at low metallicity. This simple observation will demonstrate that ALMA can probe the abundance, structure, and dynamics of molecular clouds in a wide variety of low metallicity galaxies, and these data will form a crucial contribution to understanding star formation in the low metallicity early Universe. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2015-07-02T14:09:15.000 |
| 2640 | 2015.1.00714.S | 16 | Stirring the Pot: Giant Molecular Clouds in the Local Galaxy Merger NGC 3256 | Giant molecular clouds (GMCs) are the sites of star formation in the known universe. Before ALMA, GMCs have only been observed in nearby disk galaxies. We propose to observe the nearest luminous infrared galaxy, NGC 3256, at 0.2" (~35pc) to search for GMCs. Recent ALMA observations of the nuclear starburst NGC 253 have shown that the GMCs have high line widths, surface densities and densities when comapred to Galactic GMCs. Our goal is to build a catalogue of GMCs in NGC 3256 and to compare the properties of the GMCs to GMCs in other systems. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG), Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2018-01-24T00:00:00.000 |
| 2641 | 2018.1.00312.S | 61 | Massive Molecular Filaments in a Nearby Disk Galaxy | Our goal is to discover, for the first time, massive molecular filaments in a nearby disk galaxy, NGC300, as traced by 13CO(2-1). Such structures, extending ~100pc in length, but often with ~parsec-scale widths, have only recently been identified in the Milky Way. Their kinematic coherence is a great challenge to theoretical models and simulations of the interstellar medium and its star formation activity. We aim to achieve our goal by imaging a 1kpc by 1kpc patch of the disk at high angular resolution (0.14", equivalent to 1.3pc), while also being sensitive to the largest 1kpc-scale structures. In addition to 13CO(2-1), we will also image 12CO(2-1), C18O(2-1) and the 1.2mm continuum. The "bird's-eye" extragalactic view of the expected network of massive, dense molecular filaments will allow unambiguous and detailed comparisons to be made with numerical simulations of GMC formation and evolution. [Resubmission of partially observed Cycle 4 project] | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2020-08-02T02:15:04.000 |
| 2642 | 2015.1.00973.S | 10 | HCN AND HCO+ LADDER IN THE LUMINOUS MERGER VV 114 FOR INVESTIGATING THE IR-ENGINES | The HCN and HCO+ lines have high critical densities and are known to be excellent and unbiased tracers of the dense ISM. Indeed recent ALMA observations have revealed that these lines are only seen in the nuclear and most active region of the galaxies. Furthermore, the tight correlation between L(FIR) and L(HCN) in (Ultra-)luminous infrared galaxies (U/LIRGs) suggests that these galaxies have a nearly constant star formation efficiency per dense gas mass (SFR/M(dense)). U/LIRGs are ideal sources to study the excitation of the HCN and HCO+ lines as the occurrence of high SFR suggests that the dense material is abundant near the nuclear region of these galaxies, and even the high-J transitions can be detected with relatively short integration time. Accordingly, we have been using ALMA in the past years to study the dense gas in a merging galaxy VV 114. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2017-08-24T07:03:43.000 |
| 2643 | 2013.1.01271.S | 2 | Testing feedback scenarios and clump life times in a prototypical z~2 galaxy | Theoretical models predict that key aspects of galaxy evolution including bulge formation, black hole accreation and quenching may be regulated by the dynamics of large star forming clumps which are almost ubiquitous in the gas rich ISM medium of normal high redshift galaxies. The effective relevance of this scenario depends on the longevity and the possibility of "rejuvenation" of such instabilities, both of which can be observationally constrained by probing the amount and distribution of cold gas at the clump scales. We thus propose for ~8h high resolution mapping of molecular gas content in HUDF 6462, a well studied and typical star forming z~1.5 clumpy galaxy. We target the CO(5-4) emission line in Band 6 using a 0.4" beam width for resolving individual clumps. The requested frequency range covers the rest-frame 500micron thus also offering the possibility of measuring continuum dust emission. These new ALMA data, combined with the state of the art data set available for the proposed target, will offer strong constraints on the above key questions. | Galaxy structure & evolution | Galaxy evolution | 2016-11-07T04:22:28.000 |
| 2644 | 2012.1.00435.S | 0 | Feedback in action: tracing the extreme interplay between radio jets and ISM in galaxies | We propose observations of the molecular outflow recently detected by APEX in CO(2-1) in the nearby southern AGN IC5063. This object is one of the best examples of a jet-driven outflow and the first case where cold gas (HI-21cm) has been discovered associated with such an outflow. The HI outflow has been observed to be at the location of a bright radio lobe (about 0.5 kpc from the nucleus) and an ionized outflow has also been detected at that location. The high spatial resolution and sensitivity of ALMA will allow us to trace the molecular gas in this outflow and compare this with the other phases of the gas. IC5063 is the best example where the molecular outflow can be spatially resolved and the kinematic of the gas studied and compared with theoretical predictions. The proposed observations represent a first step of a detailed study of the molecular gas in this object. They we will allow us to: 1) confirm the blueshifted wing of the CO profile detected by APEX and establish its location; 2) disentangle it from the regularly rotating gas associated with the large scale disk; 3) image the distribution and the detailed kinematics of the molecular gas associated with the outflow; 4) use all this to identify the likely origin of the outflowing molecular gas and its characteristics (mass, mass outflow rate, kinetic energy and comparison with Eddington and bolometric luminosities) Gaseous outflows are now recognized to be complex, multi-phase structures but only detailed observations in nearby objects like the one proposed here will allow us to fully understand their impact for galaxy evolution. The proposed observations of IC5063 will demonstrate that ALMA offers new and exciting and unique opportunities to study the physics of AGN-induced outflows and their role in galaxy evolution. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2015-06-13T12:51:42.000 |
| 2645 | 2011.0.00629.S | 0 | CN excitation in T-Tauri disks: a challenge to protoplanetary disks models | Gas and dust disks are ubiquitous around Pre-Main-Sequence stars of masses below 3 solar masses. Understanding their density and temperature structures is one of the major issues to study the formation of planetary systems. Theoretical studies of proto-planetary disks structure lead to a model with three layers, i.e. a photo-dissociation region illuminated by the stellar UV, a warm molecular layer and a cold gas-phase molecule depleted mid-plane. This picture is however not yet constrained by current observations. Nevertheless, existing observations of CO, CN , HCN and CCH suggest very low excitation temperature (< 10 K), and challenge the current disk model. Here we propose to take advantage of the ALMA Early Science to observe the CN J=3-2 and HCN J=4-3 lines (one setup in Band 7) in one ``cold'' disk surrounding the TTauri star DM Tau and in the ``warm'' disk surrounding the Herbig Ae star MWC 480. Combining these observations with our CN J=2-1 and HCN J=1-0 data taken with the PdBI will allow us to better constraint the excitation condition, and check if the apparent low excitation temperatures is due to sub-thermal excitation. | Disks around low-mass stars | Disks and planet formation | 2014-02-27T08:19:00.000 |
| 2646 | 2019.1.01320.S | 54 | The cold circumstellar envelopes of evolved stars in the Large Magellanic Cloud | Evolved stars are significant contributors to enrichment of the interstellar medium. Herschel observations suggest strongly the presence of cold dust around evolved stars in the LMC. The detection of significant ammounts of dust accociated with the star was confirmed by our partialy observed ALMA C5 programn, which resolved the dust envelope. Here we propose ALMA continuum and CO (3-2) emission line observations of the 4 brightest evolved stars detected with Herschel at 350 microns to complete this program. Continuum emission gives the dust mass and temperature, necessary for understanding the dust production history of the star. Resolving CO line emission allows us to characterise the differences in wind velocity between metal-poor stars, synonymous with the early Universe, and those at solar metallicity. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2021-03-02T18:34:28.000 |
| 2647 | 2016.1.00896.S | 42 | How do we get to the peak of the Cosmic Star Formation Rate Density: star formation in 0.2<z<0.8 IR luminous galaxies | Luminous IR galaxies at intermediate (0.2 | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-05-01T02:36:09.000 |
| 2648 | 2013.1.00332.S | 80 | Physical and chemical structure of massive proto-clusters | The very massive and luminous cores SgrB2(M) and SgrB2(N) are probably progenitors of very rich Arches-like stellar clusters in the Galactic center. In spite of their similar mass and luminosity, they are very different, both morphologically (M is very fragmented, N almost monolithic) and in their chemical appearence - while M is line poor, except for rich spectra of sulphur-bearing molecules, N is very line rich, and has yielded many new complex organic molecules. In this proposal, we want to do a full line survey of Band 6 toward both sources, to determine the full physical and chemical structure using 3-d radiative transfer modeling, to identify all lines and possibly find new species, and to characterize the chemical diversity spatially. This will be aided by the availability of full HIFI line surveys of both sources, which will give important constraints. | High-mass star formation, Astrochemistry | ISM and star formation | 2016-08-07T11:05:20.000 |
| 2649 | 2013.1.01214.S | 1 | Imaging the Exo-Terrestrial Remnants Orbiting van Maanen's Star | We propose to observe the archetype metal-polluted white dwarf to detect and spatially resolve cold dust from its remnant planetary system. The observational goals are thus to confirm the source of the asteroid-size mass of terrestrial-like metals residing in the stellar atmosphere, and, critically, identify the orbital regions from which this planetary material originated. A combination of bulk chemistry and formation region will provide modelers with the best empirical data to constrain theories of exo-terrestrial planetesimal and planet formation. This is an unprecedented opportunity to demonstrate to both scientists and the wider public that planetary systems, not unlike our own, can survive the death of their host star and provide the first direct image of a such a remnant. | Debris disks | Disks and planet formation | 2016-08-14T11:41:20.000 |
| 2650 | 2023.1.00634.S | 0 | Chemical effects of mm-sized grain settling in edge-on protoplanetary disks | Vertical settling of mm-sized "big" grains in protoplanetary disks not only enhances dust concentration in the disk midplane, facilitating the onset of planet formation, but also alters the disk's vertical radiation properties and temperature structure, which are the primary drivers of disk chemistry. Edge-on disks offer a unique opportunity to investigate the effects of vertical settling of big grains, as their viewing geometry enables direct imaging of vertical line emission structures. We propose a pilot study to examine how mm-sized grain settling influences the proximity of chemically active layers and the CO snow surface to the planet-forming disk midplane by observing highly inclined disks (inclination > 80 degrees) around two Class II objects: the Tau 042021 disk, which exhibits significant vertical settling of mm-sized big grains, and the HV Tau C disk, which does not. We aim to observe N2H+ 3-2 line emission in these two disks, along with DCO+, H2CO, and CH3OH emissions at 0.2-0.25" resolution, providing a first direct look at the relationship between dust settling and CO gas/ice-regulated chemistry near the disk midplane. | Disks around low-mass stars | Disks and planet formation | 2025-07-25T03:44:53.000 |
| 2651 | 2018.1.01289.S | 30 | The molecular disks of the first QSOs | The dense molecular ISM is the key to galaxy evolution because it traces the star formation reservoir. Despite its importance, it remains still little explored in the first luminous QSOs. Nowadays ALMA enables us to resolve the molecular gas emission in QSO host galaxies out to the Epoch of Reionisation (EoR). We have recently presented ALMA observations of CO(6-5) in the host galaxy of the QSO SDSS J231038.88+185519.7, which enabled us to resolve for the first time the molecular disk of a z~6 QSO. We find that the dense molecular gas emission is resolved in a rotating disk of size of 2.9 kpc, with a molecular gas mass of M(H2)=3.2x10^10 MSun, and a dynamical mass Mdyn= 4.1x10^10 MSun. We find a molecular gas fraction of M(H2)/M*=3.5, a turbulent rotating disk with v(rot)/sigma= 1-2, and a Toomre parameter Q~0.2-0.5, meaning that cloud fragmentation likely occurs in the disk. Our results on J2310+1855 prove the strategic importance of imaging the molecular gas with 1-2 kpc spatial resolution. We propose here to make a substantial step forward, by expanding this investigation to a sample of z~6 QSOs, to start exploring the properties of the dense molecular ISM of this population. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-01-18T17:03:12.000 |
| 2652 | 2015.1.00665.S | 144 | After the Fall: Mapping the Molecular Fuel in Post-Starburst Galaxies | To explain the nature of present day galaxies, contemporary models of galaxy evolution require feedback to expel a substantial fraction of the gas and dust fueling stellar and black hole growth, driving galaxies into quiescence. Post-starburst galaxies are systems found precisely in this phase - shortly after star formation has been abruptly halted - but little is known about the dust and gas content of these systems. We have recently discovered surprisingly large reservoirs of dust and molecular gas in a sample of post-starbursts. Incredibly, they are producing stars at a pace more than 10x below what is expected. A critical question is why this gas is not forming stars in line with the well-studied 'SF law'. To understand the fate of molecular fuel after quenching, we propose deep CO 2-1 mapping of 8 post-starbursts with well-measured molecular gas and dust masses, sampling a wide range of precisely determined post-burst ages from 0.3-1.5Gyr. Continuum measurements at 1.3mm will also provide powerful contraints on cold dust content. ALMA alone has the sensitivity and resolution needed to probe the state of the dusty molecular fuel left behind in galaxies 'After the Fall.' | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2017-10-28T00:00:00.000 |
| 2653 | 2015.1.00850.S | 434 | Digging within the cold Herschel sources of the NGC 6334 complex, to define the initial phase of high-mass star formation | Despite all the recent efforts to characterize the earliest phases of high-mass star formation, the existence of high-mass pre-stellar cores is still debated. NGC 6334 is the closest most massive molecular complex of the Southern hemisphere forming high-mass stars. The Herschel/HOBYS program made a survey of NGC 6334 and an utter search for cloud fragments able to form high-mass stars. HOBYS revealed 29 cold, massive dense cores (MDCs) hosting either young high-mass protostars, massive pre-stellar cores, or both. We here propose to: -follow the fragmentation of these ~0.1 pc Herschel sources down to the ~2000 AU scale of protostars -seek CO outflows to distinguish between high-mass protostars and massive pre-stellar cores -compare the fragmentation level of protostellar and starless MDCs -measure the turbulence level of high-mass protostars and massive pre-stellar cores using 13CS and N2D+ lines, respectively -look for gas stream flowing from parsec-scale to 2000 AU protostars in DCO+ and DNC -conclude on the most likely scenario to form high-mass stars: either the local collapse of a turbulent massive pre-stellar core or the clump-scale gas accretion onto a low-mass protostar. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-04-29T06:35:54.000 |
| 2654 | 2022.1.00190.S | 64 | Submillimetre water megamaser tracers of supermassive black holes | Water megamasers are playing a crucial role in understanding AGN central engine physics, and in providing geometric distance measurements to their host galaxies for Hubble Constant determination. Although the megamasers have been well-studied at cm wavelengths (22 GHz), the scientific window for their study at millimetre and submillimetre wavelengths is only just opening. Here, we propose to search the southern water megamaser galaxy NGC 4945 - already known to host water megamasers at 22, 183 and 321 GHz - for emission at nine water maser frequencies. Results of this work will inform which submm water masers are the strongest for extragalactic AGN central engine studies. In addition, it will reveal which lines are likely to be the best candidates for future mapping and distance determinations using mm/submm VLBI. The independent, purely geometric distances that could be obtained using mmVLBI can provide measurements of the Hubble Constant and black hole masses accurate to a few percent, of fundamental importance to cosmology and the understanding of AGN physics. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2024-07-05T23:32:33.000 |
| 2655 | 2017.1.01390.S | 22 | Testing Ambipolar Diffusion Models Down to 100 AU scale | Ambipolar diffusion is the key procees to redistribute the mass-to-flux ratio in the magnetic dominated star formation. It is also the core of debate between the magnetic or turbulent star formation. We propose to observe N2H+ (1-0) and NH2D (1,1) lines with the highest velocity resolution of 0.05 km/s in ALMA Band 3 toward a first hydrostatic core candidate Ophiuchus A-N6. The goal is to search for the predicted ~ 0.1 km/s difference in line profiles of coexistent ions and neutrals at 100 AU scale. The physical scale and the target of this proposal are carefully chosen to match the earliest collapsing protostellar core in ambipolar diffusion theory. The isotopes of HCO+ amd HCN molecules that have been proven as AD tracers are also included in this proposal. This proposal will examine ambipolar diffusion models to the smallest physical scale ever been observed to the present. | Low-mass star formation | ISM and star formation | 2019-03-15T08:40:25.000 |
| 2656 | 2016.1.01613.S | 34 | Dynamical flow process of a torus: Testing a radiation-driven fountain model in Circinus | We try to test one of the physically-motivated torus mode, "radiation-driven fountain model" towards the nearest type-2 Seyfert, Circinus galaxy. From MIR interferometric observations, Circinus has proven to have polar-elongated dust emission, that is typical for the fountain model (Wada 2012). We will try to reveal the geometrical and kinematic structure of the circumnuclear region of Circinus with CO(3-2) and [CI](1-0) emission lines. CO will probe the dense, mid-plane of the disk, whereas [CI] will do rather diffuse component. Especially, we expect that CO is X-ray dissociated at the close vicinity to the AGN. Hence, we should use atomic lines such as [CI] to probe the AGN-driven dusty outflow, that is the key component of the fountain model. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-05-20T01:43:40.000 |
| 2657 | 2022.1.01685.S | 38 | Unveiling the Structure, Kinematics, and Molecular Gas Properties of a New ALMA-Confirmed Radio+Sub-mm Galaxy at z=6.853 | Cycle 8 ALMA [CII] observations have confirmed the existence of a new radio+sub-mm galaxy at z=6.853 harboring a heavily obscured hyperluminous AGN - the first known source of its kind at z>6. We aim to begin characterizing this exceptional reionization-era galaxy in detail by conducting follow-up high-resolution [CII]+dust continuum observations as well as unresolved molecular line observations, enabling us to achieve the following goals: 1. We will assess whether this galaxy exhibits highly-disturbed morphology and dynamics consistent with a recent/ongoing merger and whether there is any evidence of outflows along the radio jet axis. We will detect and resolve discrete [CII]-bright star-forming clumps (as seen in the only other z>6.5 sub-mm galaxy known), providing key insight into how this extremely massive z~7 galaxy is assembling. 2. By obtaining multi-transition CO (Jupp = 6 to 16), H20, and OH spectral measurements, we will investigate the relative contributions of different heating mechanisms to the molecular gas, infer the total molecular gas mass comparing to UV-luminous quasar hosts at z>6, and quantify the depletion timescale of this rapidly star-forming system. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2024-01-10T18:32:38.000 |
| 2658 | 2012.1.00080.S | 3 | Core Mass Function of the Galactic Center 50 km/s Molecuar Cloud | In recent two decades, the young and highly luminous clusters in the Galactic center region, including Arches cluster, Quintuplet cluster, and Central cluster have been found by IR observations. The molecular clouds in the region are much denser, warmer, and more turbulent than disk molecular clouds. They are presumably the cradles of these bright star clusters. It is, however, an open question as to what mechanism is responsible for the formation of such star clusters in the cloud. The Galactic center 50 km s-1 molecular cloud is a most promising test bed to study of the star formation mechanism in the region. The core mass function of the clouds (CMF) is believed to be important for diagnosis of the star formation even in the Galactic center region. We propose multi-spices (CS, C34S, C33S, thermal SiO, H13CO+ and H42α) and wide-field imaging observations covering the whole cloud with mosaic method using ALMA to derive the CMF and size spectrum and to examine their positional deference in the cloud. This may be a key information to understand star burst phenomena as an elementary process. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2017-04-07T00:00:00.000 |
| 2659 | 2016.1.00190.S | 18 | Dissecting disks around young B-type stars | We resubmit Cycle 3 project 2015.1.00600.S, assigned priority grade B. Should our Cycle 3 project be completed, we will withdraw the present proposal. This proposal aims at characterizing the structure and properties of circumstellar disks around B-type stars. Our ALMA Cycle 0 observations demonstrated that disk-mediated accretion is a viable formation route for B-type stars. We could identify (at least) two disks around B-type stars, consistent with Keplerian rotation. However, the angular resolution was not sufficient to discriminate pure Keplerian rotation from other rotation curves, and hence derive robust estimates of the stellar mass. We propose to conduct new observations in band 7, with 3 times better angular resolution, 0.15 arcsec. By observing already proven disk tracers we will (i) resolve the disk structure, determine the rotation curve and search for radial temperature/density variations, (ii) obtain high-fidelity, high-angular images of the disks and their surroundings to search for non-symmetric distributions, (iii) compare with numerical simulations, and (iv) draw general conclusions on the properties of disks around B-type stars compared to low-mass disks. | Disks around high-mass stars | Disks and planet formation | 2018-07-20T16:52:30.000 |
| 2660 | 2022.1.01055.V | 0 | A sample of SMBH shadows, rings, accretion flows and jet bases: exploratory EHT+ALMA flux measurements | The photon ring around the supermassive black hole (SMBH) in M87 (10^9 Msun, powerful jet) has been imaged with the Event Horizon Telescope (EHT), and results on SgrA* (10^6 Msun, no/weak jet) are in the pipeline. Here we request EHT+ALMA 230GHz nuclear flux measurements of 12 SMBHs, in order to complete characterization of all ~30 SMBHs with bright > 43 GHz VLBI detections and which can be imaged at <500 gravitational radius resolution with the EHT+ALMA. UV analysis of these snapshot observations will immediately constrain jet base brightness and morphology, constrain the flux from an accretion flow, and perhaps SMBH mass. Our larger goal is to identify all sources in which near-future deep EHT+ALMA imaging can: (a) resolve the jet base thus providing constraints to jet launching theory over varying mass, spin, accretion rate, jet orientation and power; (b) resolve accretion flows and orbiting hotspots, providing constraints to accretion theory; and (c) identify SMBHs whose SMBH photon rings or shadows can be resolved using existing super-resolution techniques, thus providing constraints to gravity theories. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 2661 | 2016.1.01318.S | 44 | Prebiotic chemistry: the first detection of the 3-carbon sugar glyceraldehyde | Exploring the prebiotic chemistry present around solar-type protostars is crucial to origin of life studies. A key question is how complicated can the prebiotic chemistry become in such environments. With this proposal we aim to detect the first 3-carbon sugar, glyceraldehyde (CH2(OH)CH(OH)CHO) in the ISM, with observations towards the low-mass protostellar binary IRAS16293-2422. A detection of glyceraldehyde toward a solar-type protostellar binary would represent a significant achievement in astrobiology as well as astrochemistry, as this molecule is a precursor to the formation of ribose, the central molecular subunit in RNA. Our previous ALMA survey of IRAS16293-2422 in band 7 has enabled us to produce very detailed spectral models of this source, and compute the expected spectrum of glyceraldehyde and any line blending we expect in these observations. No experimentally determined lines of glyceraldehyde fall within the frequency range of previous studies, so with this proposal we target selected spectral windows in band 4 where the brightest lines are expected. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-05-17T04:09:27.000 |
| 2662 | 2021.1.01500.S | 153 | Unravelling the pathways of AGN-driven quenching in high-redshift galaxies | A outstanding issue in galaxy evolution is the role of AGN in the quenching of star-formation in galaxies. Recent observations with ALMA suggest that distant AGN (z~2) strongly destroy molecular gas in their hosts, implying a rapid process of quenching. This is at odds with the expectations from theoretical simulations of galaxy evolution at similar epochs. We will conclusively address this question using CO observations of 45 specially-chosen mass-selected X-ray AGN from the KMOS AGN Survey at High-z (KASHz). Along with optical emission lines from near-IR spectroscopy, all our targets have deep ALMA continuum photometry yielding accurate star-formation rates (SFRs) and stellar masses from detailed multi-wavelength modelling. We will constrain their molecular gas fractions and global molecular depletion times, and compare their variation across the plane of SFR and stellar mass to the well-developed trends already establised among normal galaxies. This will be a crucial test of the relevance of rapid AGN quenching at the peak epoch of galaxy evolution. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-09-23T21:34:05.000 |
| 2663 | 2013.1.01239.S | 11 | Probing the z=1.0 Kennicutt-Schmidt law by combining ALMA and VLT KMOS observations | It is vital to our understanding of galaxy formation and evolution to determine if the prescriptions for star formation, such as the Kennicutt-Schmidt law, are applicable to the rapidly evolving inter stellar medium of gas-rich, high-redshift galaxies. To test this, spatially resolved observations of both the star formation and the cold gas that fuels it, for typical high redshift, star forming galaxies, are required. We propose to measure the cold molecular gas masses for 11 z~1.0 star forming galaxies for which we possess spatially resolved Halpha derived star formation rates and dynamics from our ongoing VLT KMOS programme. We will infer the gas masses for our sample (via gas-to-dust ratios) with ALMA Band 7 continuum observations of the dust emission from the optically thin region of the Rayleigh Jeans tail. This approach does not rely on the uncertain conversion from CO gas mass to molecular Hydrogen. The other great advantage of this method is that we only require 10 minute integrations per galaxy to derive typical gas masses, which is significantly faster than the >1 hour required to obtain this measurement from CO line emission. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2016-09-10T00:00:00.000 |
| 2664 | 2017.1.01693.S | 701 | Chronology of Episodic Accretion in Protostars - A survey of CO and H2O snow lines | We propose to construct the chronology of episodic accretion by measuring CO and H2O snow lines via N2H+ and HCO+ emission toward 22 Class 0 and 17 Class I sources. Specifically, we plan to estimate (1) when a protostar starts the episodic accretion process and (2) the interval between bursts, which are crucial for understanding the origin of the episodic accretion. The CO/H2O snow lines allow us to probe a past burst by comparing the measured radius to the predicted one by the current luminosities; during a burst, the increase in accretion luminosity shifts the snow lines outwards, and once the luminosity goes back to normal, the snow lines move back to their initial position after some delay because of the timescale of the freeze-out process. The CO and H2O snow lines are located at different radii and densities such that the refreeze-out timescales are different: 10000 yr for CO and 1000 yr for H2O. This wil enable us to estimate the time from the previous burst in a protostar and to construct the chronology of the episodic accretion process in star formation in a statistical way. This will allow us to test if accretion bursts are triggered by disk-fragmentation at later stage. | High-mass star formation | ISM and star formation | 2019-07-06T17:18:52.000 |
| 2665 | 2013.1.00001.S | 30 | Witnessing the birth of the red sequence: the physical scale and morphology of ultra-red starbursts | We have defined a large sample of galaxies that are both faint (ergo unlensed - in this regime we cannot afford the vagaries of galaxy-galaxy lens model reconstruction) and extremely red (ergo very distant). We then further refined our sample via SCUBA-2 imaging, rejecting z<4 interlopers. The remaining galaxies represent the most intense starbursts in the z>4 Universe - the precursors of massive galaxies on the red sequence. Our goal here is to fully and directly characterise the physical scale and morphology of the dust in the 30 faintest and reddest of these z>4 starbursts - the first time a significant sample of such distant systems has been imaged interferometrically. Is the physical distribution of the dust best modelled as a compact, optically thick disk, as with local ULIRGs, or by a more extended optically thin disk, like local spirals? Is the Schmidt-Kennicutt law different in such young galaxies? What drives these early starbursts - major mergers, or the steady accretion of gas onto a disk, or perhaps something unexpected? Via the relatively simple observations proposed here, ALMA will reveal the manner in which the ancestors of today’s massive galaxies were formed. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2016-09-11T13:36:24.000 |
| 2666 | 2017.1.00025.S | 318 | Unveiling molecular gas in local Herschel-ATLAS galaxies | We wish to perform spatially resolved observations of the [CI] line in Band 8 and the CO(1-0) line in Band 3 for a sample of nearby (z~0.07) galaxies detected by Herschel to obtain two separate measures of their molecular gas masses. The [CI] line will allow us to trace the full extent of the H2 gas, velocity field, and enclosed dynamical mass. This will be compared to the well known ``traditional'' tracer CO(1-0) with which we will trace the H2 mass via the XCO conversion factor. We obtained Cycle 2 CO(1-0) data on a set of targets from the H-ATLAS GAMA 09-hr field, all of which were significantly detected. The crucial part of the project -- the [CI] data -- was, sadly, not observed in Cycles 2, 3 or 4, though we had highly ranked approved programs. It is no longer possible to pursue the sample of 09-hr sources in Band 8 since they will be observable only during the daytime. To overcome this, the subject of this Cycle 5 proposal is to obtain a complete set of [CI](1-0) and CO(1-0) data for a sample of galaxies from the H-ATLAS GAMA 14-hr field that will finally allow us to achieve our science goals. | Surveys of galaxies | Galaxy evolution | 2019-06-25T14:23:01.000 |
| 2667 | 2016.1.01235.S | 26 | Constraining Jupiter's atmospheric chemistry and dynamics from post-SL9 species mapping | In July 1994, comet Shoemaker-Levy 9 (SL9) spectacularly impacted Jupiter at 44°S. On the long term, Jupiter was left with a variety of new species in its stratosphere: CO, HCN, CS, H2O, and CO2. Their distributions have been monitored, generally with poor spatial resolution. We propose to map the distributions of CO, HCN, and CS, in Jupiter in a single band 7 spectral setup with an ALMA+ACA+TP mosaic. With a resolution of 1.1", we will reach an unprecedented high latitudinal resolution of better than 10°. The favorable observation geometry in 2017 will enable us to map the high southern latitudes, that are of particular interest for this project. We aim to: 1) Derive the vertical and meridional distributions of CO, HCN, and CS, to better understand Jupiter's atmospheric chemistry and dynamics. 2) From the CO and HCN maps, understand why CO2 (a product of CO) and HCN have such different meridional distributions when both are thought to originate from SL9. 3) Identify a potential source of exogenic material at auroral latitudes. 4) Constrain Jupiter's vertical/meridional dynamics by modeling in 3D (altitude-latitude-time) the evolution of the HCN distribution over ~20 years. | Solar system - Planetary atmospheres | Solar system | 2019-07-15T00:00:00.000 |
| 2668 | 2013.1.00278.S | 90 | Formation of complex organics in solar-type protostars | Understanding how, when and where complex organic and potentially prebiotic molecules are formed is a fundamental goal of astrochemistry and an integral part of origins of life studies. Already now ALMA is showing its capabilities for studies of the chemistry of solar-type stars with its high sensitivity for faint lines, high spectral resolution which limits line confusion, and high angular resolution making it possible to study young stars on solar-system scales. We here propose to undertake an unbiased survey of the protostellar binary IRAS 16293-2422 in the important spectral window from 329 to 363 GHz. The aim is to reveal the origin of complex organic molecules in a young protostellar system and investigate the link between this stage and the early Solar System. These data will however also have a large legacy value beyond the astrochemical focus of our group and we will therefore waive the proprietary period for the obtained data - and furthermore make the fully imaged datacubes available to the community with the first sets of papers. | Low-mass star formation, Astrochemistry | ISM and star formation | 2016-05-07T18:26:00.000 |
| 2669 | 2023.1.00428.S | 0 | Compact or large? CO observations of the faintest planet-forming disks. | Many planet-forming disks observed with ALMA snapshot surveys show unexpectedly faint continuum and CO emission. This has called into question whether disks contain enough material to build the known exoplanet population. However, no close look has been given to the fainter end of the disk population, that often shows compact unresolved continuum emission and is not detected in CO isotopologs. Whether the observations only reveal faint but otherwise extended emission, or if these disks are intrinsically compact is still not constrained. It is however critical to distinguish between these opposite scenarios. If such disks are really compact, even in their gaseous component, and optically thick, the disk inner regions may have substantial reservoirs of material sufficient to form gas giants within Jupiter's orbital radius. The aim of this proposal is to unveil the gaseous component of the faintest planet-forming disks. By observing the 13CO and 12CO(3-2) lines in 18 CO-faint Lupus we will be able to constrain if they are intrinsically compact and optically thick. If this is true,there could be an enormous potential for planet formation within 10au, in a large fraction of Lupus disks. | Disks around low-mass stars | Disks and planet formation | 2025-11-17T15:29:00.000 |
| 2670 | 2019.1.01425.S | 2 | Companions in Perseus: Dissecting the Formation Mechanism of Close Proto-Binaries | We propose ALMA observations of 12 close (<500 AU) multiple systems within the Perseus molecular cloud at 0.025" resolution to determine whether they most likely formed via disk fragmentation or turbulent fragmentation. We will do this by resolving the individual circumstellar disks in the multiple systems to determine if their disk orientations are aligned (expected for disk fragmentation) or misaligned (expected for turbulent fragmentation. This sample is selected from the 18 proto-binary systems with separations between 21 and 550 AU detected by a VLA 8mm survey toward all protostars in the Perseus molecular cloud (d=300pc). Previous ALMA data was used to examine the formation mechanism for 12 out of the 18, finding that 8 out of 12 could be consistent with disk fragmentation, while 4 appeared inconsistent. This was based on detections of rotating, circumbinary emission. Circumbinary emission, however, does not rule-out turbulent fragmentation producing a close binary from the merger of two systems that were originally at larger separations. Thus, the circumstellar disk orientations are likely to bear a more reliable imprint of their formation that we now aim to detect with ALMA | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2023-09-20T15:35:13.000 |
| 2671 | 2019.1.00862.S | 17 | Two birds with one stone: CO rotation curves of two main-sequence galaxies at z=1.5 and 2.2 | Recent observations in the Halpha ionic line have indicated that the rotation curves of high-z galaxies may be declining in the outer parts. This astonishingly suggests that dark matter played a more minor role in some galaxies during galaxy assembly and has triggered a still ongoing debate. We have analyzed [CI] (1-0) and CO (4-3) observations in three representative main-sequence galaxies at a redshift of z=2.3. Our results indicate (without unambiguously demonstrating due to low S/N) that rotation curves may not decline, contradicting the claims of falling rotation curves. We request a very deep observation in two main-sequence galaxies at redshifts of 1.46 and 2.24, which can be simultaneously observed using the same configuration. The new deep CO(4-3) and CO(3-2) lines for the z=2.24 galaxy --which correspond to the lines of CO(3-2) and CO(2-1) for the z=1.46 galaxy-- will conclude our efforts to test the remarkable possibility of declining rotation curves. We are confident that this study will provide the first-ever direct proof of how dark matter halos were distributed in the Early Universe, a result of paramount importance for Cosmology and extragalactic Astrophysics. | Starburst galaxies | Active galaxies | 2022-09-06T00:00:00.000 |
| 2672 | 2018.1.01673.S | 10 | The first detection of CO lines in a remarkably UV bright Lyman Break Galaxy at z = 7.15 | Recent theoretical studies suggest that the carbon monoxide (CO) emission lines with higher-J transitions are detectable in UV luminous star-forming galaxies in the reionization epoch. In our ALMA Cycle 4 observations, we have detected spatially resolved [CII] 158 micron, [OIII] 88 micron, and dust continuum emission in a redshift (z) = 7.15 UV luminous Lyman Break Galaxy (LBG), ID65666, at the significance levels of ~11, 6, and 5, respectively. The [OIII] and [CII] luminosities of ID65666 are the highest among so far detected in z>6 LBGs, making this object the best laboratory to investigate molecular gas phase physics in LBGs at z>6. Here we propose ALMA Band 3 observations of ID65666 targeting the CO(7-6) and CO(6-5) lines. There are two goals. First, we intend to compare the luminosity ratios among CO(6-5), CO(7-6), [CII] 158 micron, and infrared luminosities of ID65666 with those of low-z LBGs and of z=6-7 QSOs and sub-millimeter galaxies. Second, we attempt to compare morphologies and possible spatial offsets between ionized, atomic, molecular, and dust phases of the inter stellar medium. Our study will be an excellent reference case for future z>6 CO line studies in LBGs. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2021-01-15T18:12:02.000 |
| 2673 | 2016.A.00030.T | 37 | Probing chemical heterogeneity in the nucleus of a long-period comet | A long-period comet C/2015 ER61 (PANSTARRS), inactive when discovered on 2015 March 14, was found to be in outburst on 2017 April 4, and it will pass perihelion on 2017 May 9 at a distance of 1.04 AU to the Sun. This presents us with a rare opportunity to study the properties of a long-period comet (LPC) which activity was just turned on and the pristine volatines sublimated directly from its nucleus. We'd like to request a DDT observation to observe this newly turned-on LPC near its perihelion, by mapping the small scale spatio-kinematic differences in the distribution of HCN, CO, CH3OH and CS emission in band 7 simultaneously with the current configuration (0.4" beam or a linear scale of 400 km), in order to investigate the chemical heterogeneity in the nucleus of this LPC. The spectral line setup and the linear scale achieved are similar to what we had for our recent Cycle 4 observations of a short-period comet (SPC) 2P/Encke obtained on 2017 March 19 (2016.1.00695.S PI: C. Qi). This will enable us to compare the primordial volatile composition of SPC (from the Kuiper Belt) and LPC (from the Oort Cloud) relatvely free from the confounding effects of near-surface processing. | Solar system - Comets | Solar system | 2017-11-24T02:09:15.000 |
| 2674 | 2018.1.00753.S | 25 | A heavy-element radio recombination line towards a post-AGB object? | We have detected a line at 232.024 GHz towards the post-AGB object HD101584 in previous ALMA observations. The only reasonable identification is a 30alpha recombination line of Mg, Si, S, or Fe (or a combination of them). In this proposal we aim to confirm this identification by searching for the 26alpha line at 353.807 GHz in the same object. We support these observations by a radiative transfer model of recombination lines that shows that under certain conditions (reasonable in this context) heavy-element recombination lines can be much stronger than e.g. the corresponding lines of H. If successful, this will be the first detection ever of a radio recombination line towards such a cool object, and it suggests that recombination lines can be used as important tools for studying highly evolved stars (such as post-AGB objects and yellow hypergiants), e.g., magnetic field estimates, spectroscopy of chromospheres, and studies of the atomic envelopes of these objects using ALMA. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2020-01-31T22:58:29.000 |
| 2675 | 2016.1.00628.S | 56 | Discovering the Host Galaxies of z~2 Damped Lya Systems | Decades of research using absorption-line techniques have characterized the physical properties -- surface density, chemical enrichment, molecular content -- of the universe's neutral gas. While the results undoubtedly link these systems to galaxies, efforts to directly observe this association have been stymied by insufficient sensitivity and/or spatial resolution. Following on our successful program at z<1, we propose to carry out a search for redshifted CO(3-2) emission from three damped Lya systems (DLAs) at z~2. The proposed observations will allow us to (1) obtain the first detections of molecular emission from z~2 DLAs, (2) derive the star formation efficiency in the absorbers, by comparing the SFR with the estimated molecular gas mass, and (3) compare the gas dynamics revealed through metal-line absorption and CO molecular emission. This pilot program will establish whether deep sub-mm observations may link physical constraints on the dense ISM to properties of the ambient ISM defined in absorption. This would represent the first, critical step to resolving the complementary roles of molecular and HI gas at the peak of galaxy formation. | Damped Lyman Alpha (DLA) systems | Cosmology | 2018-02-15T21:50:44.000 |
| 2676 | 2019.1.00273.S | 10 | Zooming into molecular tori | In our previous ALMA proposals, we have detected for the first time with CO(6-5) the molecular torus of 10pc diameter in the Seyfert 2 galaxy NGC 1068 (Garcia-Burillo et al 2016). Surprisingly, the torus is tilted, warped, and its kinematics is dominated by turbulence and non-circular motions. We have very recently mapped the molecular tori in 7 other AGN targets, at 5-10pc resolution, and found a large variety of radii and masses (Combes et al 2019). Two of them are very dense and extend towards the center. We propose now to resolve the morphology and dynamics of these 2 tori in CO(3-2) at ~1pc resolution, with 0.015'' beam in Band 7, to explore their clumpy and turbulent structure (longest baselines C43-9 or C43-10). We will then be able to understand the torus structure, for two different radio power and star forming rates, and quantify the evolutionary phases of fueling and feedback processes (we will resolve the molecular outflow in one of them, N613). Well inside the sphere of influence of the black hole (BH), we will be able to determine more accurately its mass, for those Seyfert spiral galaxies, in a region of the M-sigma relation where the scatter is maximum. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2022-10-11T13:50:32.000 |
| 2677 | 2013.1.00486.S | 1 | Fomalhaut's Inner Asteroid Belt | We propose to obtain the first resolved images of the inner debris belt around Fomalhaut. This will provide entirely new constraints on the dynamical state of potential planets in the system, and can provide a new route for understanding the origin of Fomalhaut's outer debris ring and the controversial object Fomalhaut b. The system's inner and outer debris morphology can be compared with other known debris system architectures, building a template for understanding the implications that multiple debris belts, in any one system, have for general planet formation theory. In particular, we will be able to compare the inner and outer debris belts in Fomalhaut with the asteroid and Kuiper belts in the Solar System. | Debris disks, Exo-planets | Disks and planet formation | 2016-11-07T11:09:38.000 |
| 2678 | 2021.1.00201.S | 5 | Sub-kiloparsec mapping of the molecular gas in a quintessential merger-driven starburst at z=1.52 | We aim to map the spatially-resolved molecular gas distribution using the CO 5-4 line and dust continuum of PACS-787, an archetypal twin-galaxy merger at z=1.52 with extreme star formation rates from Herschel and ALMA. CO measurements are already available with ALMA of two transitions: J=2-1 at 2" resolution (giving total gas mass) and J=5-4 at 0.3-0.4" resolution (gas and dust mass on ~1 kpc scales). These show a merger of two massive gas-rich galaxies separated by 8.6 kpc, a high efficiency of forming stars in both nuclei, and the existence of compact (r ~ 1 kpc), likely counter-rotating disks that may funnel gas inflows to the nuclear regions. With a spatial resolution of 0.04", we will map the structure and kinematics of the two galaxies on scales of ~300 pc. A deep map of the two galaxies at such resolution will allow us to accurately model the two disks, derive their dynamical masses, constrain the L_CO to gas mass conversion factor, establish to which extent these starbursts are driven by higher gas content or higher star formation efficiency (SFE) and explore variations (radial or in clumps) of the SFE, thus shedding light on the physics of starbursts at high redshift. | Merging and interacting galaxies | Galaxy evolution | 2023-08-09T22:22:00.000 |
| 2679 | 2011.0.00009.SV | 0 | Science verification observation of Orion KL | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | High-mass star formation, Astrochemistry | ISM and star formation | 2016-06-24T14:02:07.000 |
| 2680 | 2015.1.01564.S | 26 | [C II]158 micron Emision from Absorption-Selected Galaxies at z ~ 4 | A primary science driver of the ALMA observatory is to "Detect the spectral line emission from CO or CII in a normal galaxy like the Milky Way at $z$=3...". With this goal in mind, our group has systematically surveyed galaxies in absorption to pursue this objective. Specifically, we have identified damped Lya systems (DLAs), HI-selected galaxies linked to Milky Way progenitors, with strong CII* 1335 absorption at redshifts optimal for 158 micron observations with ALMA. Our Cycle 2 program is an ongoing project targeting z~2 DLAs. With Cycle 3, we transition to z>4 where ALMA observations are far more sensitive. The proposed observations target 3 DLAs drawn from a sample of 35 systems confirmed to have very strong CII* absorption. Together with high metallicity and large kinematic profiles make these systems the ideal candidates for detection with ALMA in the strongest atomic line seen in Milky Way-type galaxies. | Damped Lyman Alpha (DLA) systems | Cosmology | 2018-01-27T16:40:31.000 |
| 2681 | 2021.2.00039.S | 9 | ALMA ingestigation into the origin of the far infrared excess emission from the hot spot of the radio galaxy Pictor A | An ALMA/ACA imaging photometry at Band 8 of the west hot spot accompanied by the radio galaxy Pictor A is proposed to investigate the origin of the far-infrared excess discovered from this objects with the Herschel/SPIRE. It was interpreted that this excess is produced in 10-pc scale (about 100 mas) substructures within the hot spot via the turbulence acceleration. However, due to the large beam size of the Herschel/SPIRE, the spatial association of the far-infrared source to the hot spot is unclear, and it is still possible that diffuse radio structures with a size of 10 arcsec associated to the host spot are the origin of the far-infrared excess. In order to settle this issue, the ALMA/ACA at Band 8 is an ideal instrument, thanks to its moderately good angular resolution and relatively large maximum recoverable size (about 3 arcsec and 15 arcsec, respectively) with a reasonable sensitivity. This observation will give an important insight into the particle acceleration process, especially the turbulence acceleration, in the hot spot. | Outflows, jets, feedback | Active galaxies | 2023-07-27T18:14:29.000 |
| 2682 | 2012.1.00185.S | 0 | High resolution observations of dense molecular gas in the Antennae (NGC 4038/39) | We propose observations of the HCN and HCO+ J=1-0 transitions in the Antennae galaxies (NGC 4038/9). These data will allow us to detect and study the dense star forming gas content of most of the super giant molecular clouds previously mapped in CO by Wilson et al. (2003). We will be able to correlate the dense gas properties with the presence or absence of super star clusters. As a secondary goal, we will attempt to detect HNC in one of the remaining bands. Furthermore, we propose to average over the remaining bands to obtain a measure of the free-free continuum emission. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2015-06-05T18:41:41.000 |
| 2683 | 2021.1.00474.S | 18 | A statistical survey for dusty starbursting protoclusters at z>4 | The overdense regions at high redshift or protoclusters are important targets to look back the origin of the environmental dependence of galaxies today. Lately several protoclusters dominated by dusty starbursting galaxies which are hardly identified in optical but luminous in IR have been discovered. They are thought to be snapshots of the most starbursting epoch of a protocluster necessary to understand the whole evolution history of clusters of galaxies. However, their expected number density is quite small (~one per 100 deg^2) and we need further sample to understand their role in the stellar mass assembly of clusters. We newly selected three candidate z>4 protoclusters as counterparts of mm sources detected with Atacama Cosmology Telescope (ACT) also using WISE and Herschel large mode survey (HeLMS) images in the HSC-SSP survey field. Since the spatial resolution of ACT and Herschel are limited, here we propose follow up observations for these candidates to confirm them by resolving and constraining the SEDs of resolved counterparts with ALMA. We request a continuum mapping for 1'.4 diameter region for each in band-4 as deep as ~0.4 mJy/beam at 5sigma limit. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2022-12-14T15:07:02.000 |
| 2684 | 2022.1.01308.S | 15 | The chemical richness of the Orion Bar and its role as a lab of CH3CN chemistry in disk-evolved systems | As one of the brightest star-froming regions in the Milky Wasy, the Orion Bar is an ideal laboratory to test the chemistry in a UV-irradiated environment. We propose high spatial resolution of the Orion Bar (~500 au scales), to study the formation pathways of CH3CN in the Bar compared to the production network in circumstellar disks. The Orion Bar is an ideal target as it has strong synergy with the JWST Early Release Science program (to be observed during 2022), which will characterize the physical properties of the Bar at sub-arcsec resolution. This dataset will provide important constraints of the chemical formation of more complex molecules and an understanding of the composition in other environments, such as circumstellar disks, which are important for planet formation. | Astrochemistry | ISM and star formation | 2024-10-16T14:01:24.000 |
| 2685 | 2015.1.00075.S | 152 | Monitoring PKS1830-211: the submm activity of the blazar and the variability of the foreground absorption lines | To better understand the launching mechanism of the jets in active galactic nuclei (AGN), we need information from the region close to its physical base, where the plasma acceleration takes place. This region is opaque in the radio but becomes gradually optically thin at submm wavelengths. We propose to monitor the submm activity of the lensed AGN PKS1830-211 over a period of five months by studying the variation of the flux ratio R between its two lensed images. R is a relative quantity that can be measured at extreme precision with ALMA (down to a few 0.1%) and free of instrumental and calibration uncertainties. A monitoring of PKS1830-211 will thus reveal the (even marginal) submm activity of the blazar at a completely unexplored sensitivity regime. In the same time, we will also monitor the variations of the absorption lines arising in the lens galaxy. These variations carry information on (micro-)changes in the morphology of the background continuum illumination and will provide information on the nature of the absorbing gas. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy chemistry | Active galaxies | 2018-01-12T00:00:00.000 |
| 2686 | 2019.1.01603.S | 9 | The first minisurvey for neutral carbon gas in debris disks around G-type stars to test secondary gas disk models | One of the most unexpected discoveries of ALMA was the detection of CO gas in debris disks. Intriguingly, most detections are in disks around A-type stars, while no CO was ever detected in debris disks around G-type stars. A current model, however, predicts the production of neutral carbon in collisions of planetesimals, and CI may trace cold gas better than CO. To detect carbon and to observationally test the current secondary gas disk models, we propose to measure the CI 492 GHz (Band 8) emission in 4 massive debris disks around G-type stars. We will (1) study the spatial distribution of dust and parent planetesimals; (2) determine the quantity and spatial distribution of carbon gas; and (3) constrain the disk viscosity. The detection of CI in CO-poor disks will provide strong support for the new secondary disk models, and pave the way for new type of future gas surveys in debris disks. In our Solar System comets play an important role in water/volatile delivery to Earth. Detection of carbon gas in outer debris belts can demonstrate that similar volatile-rich planetesimals are available in these young analogues of our Solar System, too. | Debris disks | Disks and planet formation | 2021-04-02T23:05:43.000 |
| 2687 | 2017.1.00964.S | 206 | Weighing Black Hole Masses in Low-Mass Galaxies | We propose to use ALMA observations to make robust dynamical measurements of supermassive black holes masses in a sample of 7 nearby low-mass galaxies in various Hubble type. The high resolution of ALMA observations will carry out the map of the kinematics of the rotating the nuclear molecular gas disk, resolve the black holes' sphere of influence, and measure the black hole mass precisely. Our efficient observations will carry out a better dynamical modeling constraining on these black hole masses in a larger sample of low-mass galaxies than the dynamical models of stars and ionized gas. More importantly, these measurements will provide new constraints (1) on the occupation fraction of low-mass galaxies hosting black holes, an important measurement for understanding the formation of the first black hole progenitors in the early Universe, (2) on the physics underlying the host galaxy properties vs. black hole mass scaling relations in the less understood regime of the low-mass end of both black holes and host galaxies, and (3) quantify the slopes and scatters in these relations. | Surveys of galaxies, Galactic centres/nuclei | Galaxy evolution | 2019-12-15T03:57:48.000 |
| 2688 | 2023.1.01233.S | 0 | ALMA study of the most promising relativistic jet impact region in the Galaxy | The black hole X-ray binary GRO J1655-40 has an arcmin-scale ring nebula visible in H, [S II] (diagnostic line of shocked gas) and low-frequency radio imaging that is aligned with its radio jet. This is probably the second thermal ring nebula powered by a microquasar jet after Cygnus X1. However, it is difficult to confirm the origin of the ring nebula with the existing radio and optical observatinos. Here, we propose to use ALMA to obserbe the previously identified ring structure near GRO J1655-40, detect excited molecular emission in the vicinity of the source, and determine if the morphology and emission properties are consistent with the region being powered by a black hole X-ray binary jet. | Black holes, Transients | Stars and stellar evolution | 2025-06-28T04:08:54.000 |
| 2689 | 2016.1.00681.S | 64 | Are hydrogen and nitrogen isotope fractionations related in Sun-like protoclusters? | The two stable less abundant isotopes of hydrogen and nitrogen, D and 15N, are both enriched in comets and chondrites with respect to the values measured in the proto-solar nebula. This raises the question whether the two enrichments have a common origin, and how both are linked to the past chemical history of the Solar System. Low-angular resolution observations of N2H+ isotopologues (N2D+, 15NNH+ and N15NH+) toward pre-protoclusters sources suggest a faint anticorrelation between the H/D and 14N/15N ratios. However, this result is based on low-angular resolution spectra of the sources, known to have complex morphology, hence it is an average result over the whole regions. We propose to investigate the spatial (anti-)correlation between H/D and 14N/15N in the best analogue of the protocluster in which our Sun was born, OMC2-FIR4, by imaging N2H+, 15NNH+ and N15NH+ (1-0) and N2D+(2-1) with ALMA with angular resolution adequate to resolve the protocluster members (~2''). Our results will allow us to unveil for the first time a possible link between the isotope fractionation of two of the most important elements in the universe in the material out of which our Sun was likely born. | Astrochemistry | ISM and star formation | 2018-04-07T11:49:46.000 |
| 2690 | 2021.1.00994.S | 98 | Small-scale Substructures in Transition Disks | Transition disks are a well-suited class of disks to witness the signatures of planet formation and evolution, particularly when observed at few-au resolution. At low-resolution, they appear as a single wide ring around a dust-depleted cavity. This ring indicates that mm-sized dust is trapped in the outer disk, but it is impossible to establish their complexity and the presence of substructure inside the cavity when transition disks are are barely resolved. Thus, the prevalence and properties of transition disk substructures, and of the potential planetary systems shaping them, is yet unknown. Here we propose to search for substructures at few-au (~40mas) resolution in transition disks that at ~0.2" resolve into a single ring of emission. In a well-chosen sample of Class II disks with dust-depleted inner regions (that have been partially resolved at long wavelengths, that are not known circumbinary disks, and that come from nearby star-forming regions), we will characterize substructures, and constrain the type of planet(s) that shape the cavity in transition disks with planet-disk interaction models. | Disks around low-mass stars | Disks and planet formation | 2023-08-10T20:01:54.000 |
| 2691 | 2016.1.00952.S | 177 | Resolving molecular outflows in nearby luminous AGN from the CARS survey | We propose deep ALMA CO(1-0) line mapping at a resolution of 0.6" for a sub-sample of 6 luminous nearby AGN from the spatially-resolved multi-wavelength Close AGN Reference Survey (CARS). Recent wide-field optical IFU spectroscopy with MUSE revealed the presence of ionized outflows on kpc scales around those AGN, given the presence of broad line wings with 300-900km/s FWHM. The ionized gas outflow rates are about one solar mass per year, close to the total star formation rate of these systems. Single-dish mm observations indicate a large overall cold gas content, but the integrated CO(1-0) spectra are dominated by quiescent, galaxy-spanning gas. ALMA observations are needed to 1) resolve the corresponding molecular outflows, thereby properly constraining the total outflowing gas mass and 2) study the spatially resolved star formation efficiency to test whether star formation is suppressed or enhanced due to the AGN, relative to control samples of galaxies drawn from CALIFA survey. Understanding the properties of AGN-driven outflows in these intermediate luminosity AGN is essential to link the closest low-luminosity AGN studied in detail and the powerful QSOs at higher redshift. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-02-10T18:34:37.000 |
| 2692 | 2018.1.01319.S | 357 | ACA Survey of Star-forming Molecular Clouds in the SMC | We propose 12CO and 13CO (2-1) Band 6 observations with the ACA in standalone mode for a sample of molecular clouds in the Southwest Bar and Wing regions of the Small Magellanic Cloud (SMC). We target clouds previously observed by the Hubble Space Telescope, where young solar-mass pre-main sequence stars are readily identified and act as sensitive star formation tracers. When combined with CO-based cloud masses, the joint dataset facilitates cloud-by-cloud measurements of star formation efficiency that are well-matched and directly comparable to Solar neighborhood measurements. ACA-derived molecular gas maps at 2 pc spatial resolution allow us to measure molecular gas masses, resolve clumpy cloud substructures, and improve measurements of cloud properties (e.g., surface density, free-fall time). These SMC cloud measurements significantly expand the range and diversity of environments where we can study star formation efficiency, and bridge the gap between Galactic and extragalactic star formation studies. | Low-mass star formation, Magellanic Clouds | ISM and star formation | 2020-01-18T19:40:41.000 |
| 2693 | 2018.1.01088.S | 20 | Survey of Ultracool Dwarf Radio Emission and Implications for Habitability | We propose to observe 3 ultracool M dwarf (UCD) systems with ALMA in band 3. This is part of a larger survey to characterize the emission of UCDs. Our science goals are (1) to determine the primary UCD radio emission mechanism, and (2) to investigate its impact on planetary habitability. Our immediate objective is to determine the flux density at 97.5 GHz for each proposed star, which will be used to model UCD emission mechanisms. This will seek to constrain the magnetic field strength and electron energy densities in the stars' upper atmospheres, begin to build statistically meaningful flux density measurements, and characterize the strength and occurrence of any radio flares. We request 22.94 hr (including overhead) to achieve a S/N of 10 for each source. As most terrestrial planets orbit M stars, we expect UCDs to be frequent targets for JWST and future planet hunting missions, so characterizing their behavior across multiple wavelengths is needed to develop a complete picture of the environment around M dwarfs. | Brown dwarfs | Stars and stellar evolution | 2021-05-14T01:50:56.000 |
| 2694 | 2021.1.01063.S | 162 | From merging galaxies to merging halos: large-scale structure formation in SPT2349-56 | SPT2349-56 is one of the most massive galaxy protoclusters discovered to date. So far, 30 members have been identified, along with two merging halos, a large gas filament surrounding a forming brightest core galaxy (BCG), and a pronounced change in the cluster's galaxy population at the faint end. However, these discoveries have led to numerous unanswered questions: what is responsible for fueling the massive gas filament? Are we witnessing the formation of a BCG? How many more merging halos surround this structure? Incompleteness and small number statistics are an issue for the faint number counts; are we really beginning to see a new population of cluster members? To answer these questions, we propose an ultra-deep pointing of the core, sufficient to detect more extended gas - allowing us to compare the observations to simulations of BCG growth - and to confirm the nature of the number counts in this faint regime. We will also focus on merging halos by targeting four new unresolved sources in the field of SPT2349. Lastly, we will complete our Band 7 coverage of the main SPT2349 structure, thus obtaining a complete census of this truly unique object. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2023-05-16T18:48:47.000 |
| 2695 | 2018.1.00456.S | 26 | Probing the evolutionary stages of the extremely young objects | We propose to observe three first hydrostatic core (FHSC) candidate sources, Per-Bolo 45, Per-Bolo 58, and L1451-mm in the Perseus molecular cloud complex using the C17O 2-1 and CH3OH 5_k--4_k lines in the ALMA band 6. Our ALMA Cycle 4 observations of the B1-bN, B1-bS (FHSC candidates) and B1-c (a Class 0 protostar) have revealed that the sublimation areas of the CO and CH3OH can be the good indicators for the evolutionary stage of extremely young objects of "pre-Class 0" stage. Here, we would like to expand this study to the other FHSC candidate sources. The goals of this project are 1) studying the evolutionary stages of the FHSC candidate sources using the sublimation radii of CO and CH3OH, 2) searching for the point-like CH3OH emission from the FHSC. The CH3OH emission from FHSC and more evolved protostellar source can be discriminated using the rotational temperature derived from 24 transitions in the band. In addition to C17O and CH3OH 5_k--4_k lines, we also plan to observe the H2CO 3_1,2--2_1,1 and HDO 3_1,2--2_2,1 lines and 1.3 mm continuum emission. These lines and continuum are also helpful in understanding the physical and chemical conditions of the sources. | Low-mass star formation | ISM and star formation | 2021-02-13T03:19:44.000 |
| 2696 | 2021.1.00917.S | 158 | The chemical evolution in the ejecta of V4334 Sgr | V4334 Sgr is an enigmatic object that underwent a very late thermal pulse (VLTP) a few years before its discovery in 1996. It is the only well observed example of a VLTP. It baffled the scientific community with its extremely fast evolution which invalidated existing theories. During the VLTP, the star ingested its remaining hydrogen-rich envelope into the helium shell flash zone where it underwent nuclear processing and was subsequently ejected as a new, hydrogen-deficient nebula. After the ejection, molecules started forming in the nebula and this process is still ongoing. Models predict that the chemical composition will change at such a fast rate that it can be followed in real time! Existing observations give tantalizing hints that this may indeed be happening, but currently there is insufficient data to rule out the alternative explanation that the excitation conditions are changing. With this proposal we aim to collect sufficient data to settle this issue and derive the evolution of the column density of selected molecules with time. | Post-AGB stars, Evolved stars - Chemistry | Stars and stellar evolution | 2023-06-01T09:20:41.000 |
| 2697 | 2015.1.01286.S | 18 | Molecular tracers of hidden AGN: Spatially resolved chemistry in Circinus | Recent studies reveal that a significant fraction of the AGN population may be undetected in X-rays surveys because of the extreme obscuration. Molecular emission in the mm/submm can penetrate large columns of dust and gas and probe the inner regions of Compoton-thick AGNs. The HCO+/HCN line ratio has been proposed to trace AGN activity but it is not clear if it is regulated by X-ray chemistry or shocks. Also, recent observation in obscured luminous infrared galaxies have shown that other species, such as vibrationally excited HCN and HC3N may be better tracers of obscured AGNs. We propose to map the dense gas in the Circinus galaxy in order to assess the reliability of molecular AGN tracers with spatially-resolved observations. The galaxy hosts the nearest Compton-thick Seyfert 2 nucleus and is the perfect target to study the dense interstellar medium of obscured AGNs in great detail. | Galaxy chemistry | Galaxy evolution | 2017-09-07T14:14:46.000 |
| 2698 | 2016.1.00954.S | 25 | Physics of the interstellar medium of galaxies in the reionization era: the [OIII]-to[CII] line ratio | We propose the first systematic survey of the ratio of the [OIII] 88 micron line to the [CII] 158 micron line of four apparently bright galaxies at 66 with the [OIII] line about a decade prior to those using ultraviolet lines with ELTs. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2018-07-27T04:20:38.000 |
| 2699 | 2022.1.00828.S | 20 | Zooming into the small disks | High-resolution ALMA images have established dust substructures as a common feature in bright and large disks. However, demographic studies suggest that the vast majority of disks are faint and compact, for which observations that well resolve the dust distribution in these small disks are scarce. The ubiquity of substructures across the full spectrum of disk and stellar properties must be indicative of an important process that regulates disk evolution and the planet formation process. We propose to image a sample of 7 compact disks (radius of 18-36 au) at very high angular resolution of 15 mas (2-3 au) to search for dust substructures. By targeting fainter disks around less massive stellar hosts, our sample selection is designed to be more representative of the bulk disk population, and well suited to address if substructures are a universal characteristic of protoplanetary disks. The lack of substructures at such high resolution would then suggest a population with distinct evolution paths, which will be further probed by our requested CO line observations. | Disks around low-mass stars | Disks and planet formation | 2024-12-28T00:58:23.000 |
| 2700 | 2016.1.00374.S | 37 | Spatially resolving the wind acceleration zone of the AGB star W Hya | The interplay between the dust formation and the mass loss in AGB stars is not yet understood well. Our recent high-spatial resolution polarimetric imaging of the well-studied AGB star W Hya has successfully spatially resolved the clumpy clouds of large (0.4-0.5 micron) grains very close to the star (~2 stellar radii). We propose ALMA observations of the HCN (3-2) line at 266 GHz. which is thought to form behind the pulsation-induced shocks close to the star. We aim at mapping the velocity field within ~10 stellar radii with a spatial resolution of 30 mas. COmparison of the spatially resolved velocity field and the polarimetric images of the clumpy dust clouds enables us to directly examine whether or not the scattering of photons by large grains is driving systematic outward motions as proposed by the current theoretical models. This will significantly help us clarify the driving force of the mass loss in AGB stars. In addition, the ALMA data of the HCN line are important for improving our understanding of the non-equilibrium chemistry governed by the shocks. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2018-08-14T05:47:39.000 |
| 2701 | 2017.1.00480.S | 56 | Spatially resolved observations toward a ~10AU disk around a Very Low-Luminosity object in Taurus | Our ALMA Cycle 0,1 observations toward a high-density core, containing a very low-luminosity object (VeLLO), revealed the complex and dynamical nature with some indications of becoming a multiple stellar system in the future. Our new ALMA Cycle 3 data with the angular resolution of ~0.1" (~20 AU) have successfully detected a very compact disk-like structure at the VeLLO with an indication of the Keplerian rotation. Although the disk is deeply embedded at the center of the core, it seems to be isolated from the surrounding environment. Further high-angular resolution observations of the disk structure around the VeLLO would be needed to clarify the actual evolutionary stage and the disputable origin of this object. We propose follow-up observations toward this unique source to resolve the disk with an angular resolution of ~4 AU. Band 6 continuum and CO lines will clarify whether the disk is indeed truncated from surrounding gas or not and will further constrain the disk properties, such as the stellar mass, to evaluate numerical models of protostar evolution. | Low-mass star formation | ISM and star formation | 2019-02-23T01:02:12.000 |
| 2702 | 2022.1.01490.S | 13 | Phosphine in a prestellar core | Phosphorous-bearing molecules, such as nucleic acids and phospholipids, are essential for life on Earth. Then, understanding in which chemical forms phosphorous exists in star- and planet-forming regions and how phosphorus is delivered to planets are of great interest from the view point of the origin of life on Earth. Phosphine (PH3) is thought to be a key species to understand the phosphorous chemistry, but never has been detected in star- and planet-forming regions. We propose ACA stand-alone observations of PH3 toward a prestellar core. The first detection of PH3 will allow us to evaulate the amount of elemental phosphorous available for gas-ice chemistry in the prestellar core. | Astrochemistry | ISM and star formation | 2024-08-21T21:04:45.000 |
| 2703 | 2015.1.00091.S | 10 | Breaking Cosmic Dawn: Studying z~7 Galaxies with ALMA | Was reionization gradual or did it occur instantaneously? When did it occur and which sources were responsible? To answer these questions we need to unambiguously detect galaxies at z~7 and study their star formation properties. This proposal will achieve this by measuring [CII]line in a sample of z~7, highly magnified due to gravitational lensing, yet intrinsically ordinary galaxies selected from our large Spitzer and HST campaigns. All galaxies have spectroscopic detections from HST grism and/or Keck data and measured evolved stellar population from Spitzer data. We will also compare [CII] and UV/optical emission to the predictions from simulations, and investigate whether the relation between star formation rate and L[CII] differs from the local universe due to modified Kennicutt-Schmidt relation at z~7 or low metallicity. The proposed observations have sufficient resolution and depth due to gravitational lensing to test both scenaria. This proposal will thus firmly establish ALMA as a major facility for studies of galaxy formation at the reionization era. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2017-09-14T22:39:02.000 |
| 2704 | 2018.1.00493.S | 98 | Probing CN excitation and abundance in dense gas in luminous infrared galaxies | Dense molecular gas is abundant in luminous and ultraluminous infrared galaxies, where the intense starbursts produce abundant ultraviolet radiation. This gas is often traced via HCN, which can also be enhanced in the X-ray dominated regions near an AGN. CN is a particularly interesting molecule that is linked to HCN in astrochemical networks when strong ultraviolet or X-ray radiation is present. Recent ALMA observations have shown that the CO/CN(1-0) line ratio can vary by more than a factor of 10 from galaxy to galaxy and systematic variations are seen inside individual galaxies as well. Here we propose to use multiple lines of CN and HCN to map the dense gas abundance, to interpret the variations seen in the line ratios, and to constrain the source (starburst, AGN, turbulence) of the excitation of the dense gas. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2019-11-30T21:23:58.000 |
| 2705 | 2019.1.01739.S | 114 | Planet Formation and Survival in Newly-Forming Binary Systems | The majority of Sun-like stars form with binary companions, and their dynamical impact profoundly sculpts the formation and survival of their planetary systems; most planets don't survive, but a substantial minority do. Understanding binary assembly and predicting planet survival requires directly connecting the properties of binary systems to the evolution of their planet-forming disks. We propose to use ALMA for 15.81 hours in Band 6 to characterize our unique sample of 8 young disk-hosting binaries that have well-determined binary orbits. We will use the most extended configurations (C8-10) to spatially resolve the circum-primary, -secondary, and -binary disks, testing: 1) where the disks are located in binary systems, 2) alignment of inclination/rotation among disks with the binary orbit and stellar spin, 3) whether binaries imprint signatures of dynamical interactions (gaps and spirals), and 4) the mass budget available for assembling planets in binaries. In summary, our program will connect protoplanetary disk evolution to the features of binary orbits, distinguish binary formation models, and demonstrate which binary properties drive the survival/destruction of planets. | Disks around low-mass stars | Disks and planet formation | 2022-10-25T18:37:03.000 |
| 2706 | 2023.1.00565.S | 0 | Dynamical mass constraint of an ULX | Ultra-Luminous X-ray Sources (ULXs) are extremely bright (>10^39 erg/s) and compact X-ray sources. They are prime candidates for the Intermediate Mass Black Holes (IMBH) with sub-Eddington accretion, or stellar-mass BHs with super-Eddington accretion. To distinguish which types of the BH are present in ULX is one of the biggest questions in modern astronomy. Recent ALMA observation detected CO(2-1) emission line associated with the ULX NGC 5408 X-1, with a beam size of 0.56"x0.70" (Config C-3). Assuming the observed velocity dispersion is due to the Kepler motion, the central mass is constrained with <160 M_solar. With an additional observation in which the angular resolution is 0.3", we are able to conclude whether the central mass is ~10 M_solar (stella-mass BH) or ~100 M_solar (IMBH). If the central mass is 10 M_solar, the rotation velocity decreases down to 0.22 km/s in the central region within 0.3", whereas the velocity increases up to 0.44 km/s if the 100 M_solar case. To complete this study we propose the CO(2-1) observation with the C-5 or C-6 config. Consequently, these observations allow us to conclusively resolve the longstanding question on the nature of the ULX. | Black holes | Stars and stellar evolution | 2025-11-20T01:10:38.000 |
| 2707 | 2021.1.01683.S | 217 | The total molecular gas content of the most luminous QSO 2s at 0.4 < z < 0.8 | The role of the molecular gas in AGN feedback is still a matter of debate. In order to investigate this issue further, we propose ACA CO(2-1) observations of a sample of 30 of the most luminous nearby QSO 2s, with log(L[OIII]) > 43 [erg/s], at 0.4 < z < 0.8. These objects are representative of quasars at cosmic noon, when their feedback on host galaxies should be the strongest in cosmic history. Aiming to map this feedback, our goal here is to measure the integrated CO (2-1) and continuum fluxes in order to: (1) obtain their total molecular gas masses M(mol); (2) investigate the fraction of M(mol) relative to the total stellar mass, verifying if it differs from objects on the main sequence of star formation; (3) investigate the relation between M(mol) and their other properties (e.g. luminosity and spectral features); (4) look for signatures of strong outflows; (5) plan for higher resolution 12m observations to probe extended emission and investigate the presence of resolved outflows. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2022-12-02T17:33:20.000 |
| 2708 | 2023.1.00729.S | 0 | Torsionally-Exicited CH3OH at Band 1 as a Promising Probe of First Core | We propose to observe the first core in the torsionally-excited CH3OH (vt=1, 1_0-0_0 A+) line at Band 1. Whereas it has been difficult to observationally confirm the first core because it is heavily obscured by the dusty envelope, ALMA Band 1 observations provide us with a unique opportunity to directly observe the emission from the first core since the dust is optically thinner in Band 1 than in the other bands used so far. Since the vt=1 CH3OH line requires a high temperature (>300K), we can expect that this emission does not come from the infalling envelope (T < 20K) but from the layer of the accretion shock at the surface of the first core. We propose the ALMA Band 1 observation of L1451-mm, which is one of the most promising candidates for the first core. In addition to the vt=1 CH3OH emission, we plan to observe dust continuum emission at 7mm, vt=0, multi-transitional CH3OH emission, and the carbon-chain species to investigate the physical and chemical state of L1451-mm. With the proposed ALMA Band 1 observations, we will have important observational insights of the initial condition of star formation and the first core. | Low-mass star formation | ISM and star formation | 2025-11-19T00:51:23.000 |
| 2709 | 2012.1.00786.S | 2 | Molecular envelope of WISE J180956.27-330500.2: The first example of ongoing mass eruption after thermal pulse | We propose CO, SiO, and HCN molecular line observations of WISE J180956.27-330500.2 (hereafter WISE J1810) with ALMA. WISE J1810 was discovered very recently by us (Gandhi et al. 2012) as an object with a peculiar 2MASS-WISE spectral energy distribution (SED). We propose that the object is an asymptotic giant branch (AGB) star presently experiencing an episodic mass-loss event following a thermal pulse. If this is the case, it is the first opportunity of real-time observation of AGB mass ejection at thermal pulse. The infrared SED of this object is rapidly evolving over the past 15 years and updated observations over a broad wavelength range are essential. ALMA is the only available facility in mm and sub-mm range that has sensitivity and spatial resolution high enough to detect molecular lines from the object. The ALMA data will provide indispensable information of the recently formed circumstellar envelope. The main scientific objectives of this observation are (1) to measure the total gas mass expelled in the recent mass ejection, (2) to measure the expansion velocity, and (3) to determine the chemical condition (i.e., oxygen-rich or carbon-rich) of the envelope. This program will reveal the nature of an ongoing mass eruption after a thermal pulse in real-time for the first time. Detailed study of this object shall clarify or revise our idea of mass-loss and AGB evolution, and eventually the cosmic cycle of matters and chemical evolution of the universe. We plan to observe CO, SiO and HCN lines in Band 7. The requested observing time is 5.33 hours. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2016-09-22T19:37:58.000 |
| 2710 | 2017.1.00602.S | 49 | Confimation of Blindly Detected [CII]158um emitter candidates at z = 6.0 and 6.5 | In order to obtain the first conclusive evidence of blind detections of millimeter emission line sources, we propose follow-up observations of blindly detected two [CII]158um emitter candidates at z=6.0 and 6.5 in ALMA Deep Field in SSA22. In the previous observation, the candidates show S/N ratios of 6.5 and 6.2 sigma. They are faint in far-infrared, optical to near-infrared wavebands. For confirmation of the blind detections and determination of their redshifts, our proposal here is observation targeting the detected [CII] line emissions at band 6 and CO(6-5) emission lines at band 3 with the setting of 0".7 angular resolution to maximize sensitivity. The total observing time is 15.3 hours. Our proposing science goals are: (1) Confirmation of discovery of new galaxy population which are faint in both of optical/far-infrared continuum (2) Revealing gaseous properties of the new galaxy population at z ~ 6 (3) Estimation of star-formation rates and molecular gas masses of high-redshift normal [CII] emitters (4) Cosmic star-formation rate density and, at the first time, molecular gas mass density at z = 6.2. | Surveys of galaxies, Dwarf/metal-poor galaxies | Galaxy evolution | 2019-04-20T20:27:29.000 |
| 2711 | 2021.1.01307.S | 12 | Mapping the complex interplay between massive star clusters and their local ISM in a low-metallicity galaxy | We propose 12CO(1-0) and 12C(2-1) observations to map at 42pc (0.5") resolution the existing molecular CO gas in the central 5"-10" (425-850pc) of the blue compact dwarf galaxy Mrk996. This data will be used to investigate the extreme ISM physical conditions driven by the feedback effects of a young, nuclear super star cluster. These properties, namely complex gas kinematics and turbulence, very high density and extinction inhomogeneities, high ionization conditions and gas-phase metallicity of only 20% solar, make this target a unique laboratory to perform a comprehensive study including cold and warm phases of the ISM in the vecinity of a nuclear SSC. We will combine a wealth of existing X-ray, UV and optical datasets targeting ionized gas with the missing piece: spatially resolved molecular gas over spatial scales of few tens of pc. The proposed ALMA observations will provide a coherent picture of the sub-kpc ISM structure of Mrk996. Such multifrequency study is essential to constrain feedback models in an environment which closely resembles those common at high redshift. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2023-05-10T14:50:45.000 |
| 2712 | 2022.1.01204.S | 2209 | Forming hub-filament systems: An unbiased study of the gas kinematics of increasingly complex filamentary structures | Converging network of filaments, also known as hub-filament systems (HFSs), are known to host the formation of some of the most massive stars in the Milky Way. However, the physics that link the formation and evolution of HFSs with the formation of massive stars remains unclear. It has recently been proposed that HFSs could come together as the result of clump collapse, while other scenarios, invoke turbulence-driven filament-filament collisions, or cloud-cloud collisions as a formation mechanism. Here, we propose to unveil the time evolution of filamentary structures towards the formation of HFSs. For that purpose, we propose to follow-up with ALMA a complete sample of clumps of varying stages of evolution, with varying filament complexities and masses. In combination with dedicated numerical simulations of cloud evolution, we will use ALMA to map the dense gas kinematics of all clumps to produce time-dependent gas dynamics estimators. With both numerical and observational data in hand, we will in a position to determine what evolutionary path(s) HFSs follow. | High-mass star formation | ISM and star formation | 2024-05-19T17:33:49.000 |
| 2713 | 2018.1.00900.S | 27 | Measuring the radial profile of the maximum grain size in the 4-planet CI Tau system | CI Tau is the only example of a young hot Jupiter in a disc bearing system and our Cycle 4 high resolution data has demonstrated the presence of three annular gaps in the Band 6 images suggesting the presence of three further giant planets at orbital radii of 13, 39 and 100 au. It thus represents the most fully fledged protoplanetary system ever detected with its planets spanning a record factor 1000 in orbital radius. Interpretation of this spectacular image however requires a knowledge of the radial profile of maximum grain size in the disc to (i) estimate the dust opacity (thus the dust surface density) and (ii) to assess the level of coupling between dust and gas across the disc. The requested Band 3 observations at a resolution of 7 au will allow us to readily distinguish two scenarios: one in which the grains are small and well coupled to the gas (and thus where the dust to gas ratio does not vary radially) and the commonly adopted scenario where the grains have grown to mm sizes. Distinguishing these scenarios is essential in order to characterise this system, to quantify the disc's budget of dust and gas and to refine estimates of the planetary masses involved. | Disks around low-mass stars | Disks and planet formation | 2020-11-14T19:45:11.000 |
| 2714 | 2018.1.00585.S | 235 | ALMA-SPONGE: the role of neutral hydrogen in diffuse interstellar chemistry | 21-SPONGE has obtained very sensitive HI absorption spectra in the direction of 57 background radio sources. For about 300 individual velocity components we measured HI excitation tempertaure (Ts), HI column density, and the sonic Mach number (Ms), as well as the total HI column density for thermaly-stable and unstable phases along each line of sight. For a sample of 22 21-SPONGE source we propose to measure absorption of key molecular species in the diffuse ISM: HCO+, HCN, HNC and CCH. While commonly detected in the diffuse ISM, abundances and abundance variations of these species are still not well understood. The HI spectroscopy provides key information regarding the kinematic temperature of gas, and its turbulent properties, allowing us to search for environmental and dynamical effects that play an important role in molecule formation and evolution. The key scientific objectives are: compare how the column density and line width of different species correlate with Ts and Ms, investigate the correlations of column densities of different species and compare with model predictions; and investigate the role of UV radiation field on both gas temperature and chemistry. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-08-14T02:27:18.000 |
| 2715 | 2015.A.00009.S | 10 | [CII]line emission in a normal galaxy at z=7.36 | One of the most outstanding questions in galaxy evolution today corresponds to the formation of the first galaxies during the epoch of cosmic reionization. A key step is to identify and secure spectroscopic redshifts for these galaxies. Here, we propose to use ALMA to unambiguously confirm the most significant [CII] line emission candidate at z=7.360, discovered in our ALMA 1.2-mm spectroscopic survey of the Hubble Ultra Deep Field (HUDF). These 1-hr on-source observations will allow us to set the record distance for [CII] line emission in a normal galaxy, and enable detailed studies of the ISM well into the reionization epoch. It is now the ideal time to conduct these observations, while in compact configuration. Waiting for confirmation in cycle-4 would put this exciting discovery, and potential follow-up observations (higher resolution imaging, other spectral line diagnostics), to halt for at least 1.5 years. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2017-01-21T20:47:30.000 |
| 2716 | 2015.1.00147.S | 58 | Probing the Inward Motion in the Class 0 Protostar NGC 1333 IRAS 4A | Although gravitational collapse has been widely accepted from the theoretical viewpoints of star formation, the observational study of infall motions is usually a challenge. A major issue is that such kinematic features at relatively low velocity are easily contaminated by other star formation activities. We request ALMA observations towards NGC 1333 IRAS 4A to explore gas kinematics down to a scale of 50 AU. Together with the previous investigations over relatively large scale infall motions in IRAS 4A, we aim at establishing a comprehensive picture of the infalling motions from large to small scale in this region. Thanks to the flexible spectral capability, we can simultaneously capture five H2CO transitions with various energy levels, which trace different layers of infall motions. We expect to extract with radiative transfer models the physical parameters of the infalling gas from the observed spectra, determine whether the spatial distribution of infall speed is consistent with free-fall, and explore the role of forces other than gravity (such as magnetic field) in the collapse dynamics. | Low-mass star formation | ISM and star formation | 2017-11-25T17:49:31.000 |
| 2717 | 2015.1.00280.S | 34 | Lyman excess and accretion in OB-type (proto)stars | Taking advantage of the VLA/CORNISH and Herschel/Hi-GAL unbiased surveys, we have recently estimated the Lyman continuum and bolometric luminosities of a sample of bona-fide, young Galactic HII regions. An intriguing finding of our study is that 1/3 of these have Lyman continuum emission in excess of the maximum value expected for the observed bolometric luminosity. We have also searched for infall signatures in the molecular clumps around the HII regions and found that those with Lyman excess are preferentially associated with infall signatures. Conversely, the molecular gas around HII regions without Lyman excess does not appear to be infalling. Based on these results, we now want to confirm the existence of a tight association between infall and Lyman excess by imaging the molecular and ionized gas towards two selected HII regions with Lyman excess and infall signatures. Our expectation is that the proposed ALMA observations will resolve the velocity field around and inside the HII region and will establish the existence of accretion onto the early-type star. | High-mass star formation, HII regions | ISM and star formation | 2017-04-08T10:06:54.000 |
| 2718 | 2013.1.00591.S | 4 | The Interstellar Medium and AGN Feedback in a Young QSO | We propose to observe the redshifted far-infrared fine structure transitions of ionized carbon and neutral oxygen, as well as dust continuum from the massive ultraluminous host of the J0927+2001 QSO at z=5.7722. This is a physics-driven proposal with three main goals: 1) We will use fine-structure diagnostics to determine the physical conditions in the starburst within the host of J0927, producing a high S/N map of its [CII] 158 um and continuum emission and detecting the [OI] 146 um transition. 2) We will study gas kinematics, merging activity, and likely outflow superwinds using [CII] spatially resolved spectroscopy. 3) We will detect possible Milky Way-class objects in the FOV within a redshift range of +/- 0.05 (+/- 5 Mpc) from J0927, likely at the center of an early overdensity and destined to become a central cluster galaxy. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2016-06-04T20:26:08.000 |
| 2719 | 2016.1.01285.S | 26 | H3O+: Are the clouds in the central 50 pc of NGC 253 exposed to the X-rays from a black hole? | We propose to use ALMA to image the ortho-H3O+ transition at 396 GHz with a resolution of a few pc toward the starburst galaxy NGC253. This is the only submm line of H3O+ which is not affected by dust radiation pumping and will therefore be an excellent tracer of density. In contrast with the other submm lines that can be excited excited at low densities by dust emission, the 396 line will trace the high temperature, high density clouds with high ionization fraction in the nucleus of NGC253. The combination of the 396 GHz line images with those already obtained with ALMA of the para-H3O+ line at 364 GHz will provide the densities over a wide range (from few 10^3 cm-3 to 10^7 cm-3) and reliable H3O+ abundance of the clouds in NGC253. The spatial distribution of H3O+, its abundance and the densities will be used to establish the local origin (UV, X-rays and/or cosmic rays) of the enhanced ionization rates. In particular, we will explore the possibility that clouds within 50 pc of the center of NGC253 show the enhanced H3O+ abundance expected if they were affected by the X-rays from an intermediate mass black hole as suggested by the observed X-ray emission with Chandra. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2018-01-31T13:10:59.000 |
| 2720 | 2021.1.01323.S | 18 | Detecting [OIII] 52 micron emission at a z=7 galaxy to better constrain ISM properties | Far-infrared [OIII] emission is an essential tool to probe high redshift galaxies with ALMA. The emission lines arise from HII regions in the interstellar medium (ISM), thus it can constrain the ISM properties, such as the gas phase metallicity, gas density and so on. So far, several z~6-9 galaxies have been spectroscopically determined by [OIII] 88 micron emission, including one z=7.212 galaxy named SXDF-NB1006-2. However, a theoretical model of [OIII] emission shows a degeneracy between the gas density and the metallicity constraints from the current [OIII] 88 micron data. The model also predicts a significant improvement of the constraints by combining another [OIII] emission line at 52 micron. Here, we propose observations targeting the [OIII] 52 micron line to better constrain the ISM properties in SXDF-NB1006-2. A successful detection will break the density-metallicity degeneracy of the galaxy. This program will open a new window to probe the ISM of galaxies in the epoch of reionization, through which better understandings of cosmic reionization, stellar formation of the first galaxies, and galactic chemical evolution can be expected. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-09-27T04:15:13.000 |
| 2721 | 2019.2.00072.S | 50 | Filament and high-mass star formation triggered by tidally-driven colliding HI flows in the LMC | Recent observations confirmed that filamentary structures are widespread across the Galactic molecular clouds and massive filaments are supposed to be precursors of high-mass stars. Although large-scale colliding flow may be a promising event to form such filaments, the idea is not well constrained observationally. The Large Magellanic Cloud (LMC) is a suitable target to investigate the effect of galactic-scale kinematics thanks to its nearly face-on view. Recent ALMA observations toward a few particular objects in the LMC found that there are massive filamentary clouds within a possible compressed layer, which is originated from HI colliding flows induced by the last tidal interaction between the Magellanic Clouds. Our detailed HI analysis shows that the same compressed velocity components are almost ubiquitous in the other active star-forming regions in the LMC. In this new program, we will carry out survey-type observations toward these regions to search for massive filamentary clouds and investigate the environmental dependence of their properties. This is the first comprehensive exploration to study the relation between the low-density HI flows and high-density CO filaments. | High-mass star formation | ISM and star formation | 2021-04-30T19:48:25.000 |
| 2722 | 2021.1.00738.S | 20 | Evaporating ices in planet-forming disks | New planetary systems are created from the dust and gas orbiting young stars. The chemical make-up of these planets and the potential for these systems to produce habitable environments is set by the composition of the disk. ALMA has shown that most disks are depleted in volatile oxygen, with C/O>1, and that oxygen-bearing COMs (e.g. CH3OH) are not as abundant as hydrocarbons and nitrogen-bearing COMs. We propose high sensitivity observations to quantify the composition of the only two disks observed so far to be rich in volatile oxygen- HD100546 and IRS 48. In these disks the full volatile content is observable due to sublimation of ices at the irradiated cavity edge. We will target over 20 different molecules and will be sensitive to COMs important for pre-biotic chemistry, e.g., methyl-formate, dimethyl ether and acetaldehyde. With CH3OH already detected, these sources are the best candidates to detect further molecular complexity at the epoch of planet formation. These data will give the first robust comparisons between hot cores, disks and comets giving key insight to the origin molecular complexity in disks - in situ formation or inheritance. | Astrochemistry | ISM and star formation | 2023-10-21T17:44:36.000 |
| 2723 | 2015.1.00667.S | 138 | Mass assembly in the pre-stellar phase of high-mass star formation | The formation of massive stars is a "family affair" - they are born in a cluster together with many low- and intermediate-mass stars. The low-mass population of protostars bears critical information on the initial mass distribution of a forming protocluster. Our recent ALMA observations of a dense IRDC clump resolved 38 individual cores (0.5-16 Msun) within a 0.8 pc diameter, revealing a top-heavy core mass function (CMF) and a significant deficit of low-mass (1-2 Msun) cores. We propose to extend the study to a well selected sample of 12 intrinsically cold clumps - to maximize the probability of targeting truly pre-stellar phase, in order to uncover the genuine *initial* mass distribution. We design the observations with a careful strategy to ensure a robust cross comparison between the sources. The proposed study represents a major step forward in our understanding of the mass assembly process at the very beginning of cluster formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-06-14T14:52:26.000 |
| 2724 | 2016.1.01073.S | 13 | Probing the magnetic fields at the base of relativistic jets through Faraday rotation observations | We apply for 3hrs of ALMA time in the full polarization mode to study the jet magnetization and particle composition in the innermost part of the jet in the nearest quasar 3C273 at 1mm. This is crucial for understanding the jet dissipation mechanisms in the millimeter-emitting regions. Taking advantage of the wide bandwidth of the ALMA band 6, we aim to measure the Faraday rotation effect across the band in order to look for the predicted extremely high rotation measures (RM) of > 10^5 rad/m^2. We will model the Faraday rotation and frequency-dependent polarization behaviour to distinguish between Faraday rotation happening inside or outside of the emission region. Our numerical simulations show that if the jets are highly magnetized, the RM in the boundary layer of the jet will dominate over the RM within the jet, which allows us to probe the jet magnetization through the RM observations. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-03-03T10:32:07.000 |
| 2725 | 2019.1.01157.T | 30 | Constraining the powering mechanism in Fast Blue Optical Transients | FBOTs (Fast Blue Optical Transients) are a newly accessible class of transients with luminosities and evolutionary timescales that challenge traditional Supernova (SN) models. To date, these rapidly evolving luminous transients have mostly been studied in the optical/UV regime, which is of thermal origin and is not sensitive to the nature of the underlying energy source and properties of the explosion's fastest ejecta. In particular, only one FBOT has been observed at millimeter wavelengths, and yet these observations are crucial to probe the immediate environment density and profile, as well as determine the early blast-wave dynamics. As part of our comprehensive multi-wavelength campaign on FBOTs, we propose to observe one nearby FBOT discovered in Cycle 7, to (i) constrain the mass-loss history of the stellar progenitor and (ii) test for the presence of an engine driving the explosion. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2022-05-12T17:12:51.000 |
| 2726 | 2022.1.00526.S | 83 | Tracing the ISM enrichment from massive stars at the peak of cosmic starformtion | 12C and 13C abundance ratios have long been considered to be a diagnostic of of the enrichment history of the ISM and a tracer for the shape of the IMF. Observations of CO isotopes indicate that 13C is strongly under-abundant in strongly star-forming galaxies at high redshift and recent finding have concluded that this can only be explained by a top heavy IMF. This has far reaching consequences but the result is only based of the observations of five galaxies at cosmological redshifts. We here propose a study of 13CO and C18O in conjunctions with the main isotope in an additional sample of six galaxies at z=2-3 to increase the statistical footing of this finding and to test potential biases in this result by analysing the proposed suit of lines with state of the art radiative transfer tools. | Starburst galaxies | Active galaxies | 2024-03-01T14:54:17.000 |
| 2727 | 2019.1.01642.S | 10 | 0.1'' Resolution mm-Interferometry of a Highly Magnified Lyman Break Galaxy at z=3.07 | We propose deep and high spatial resolution (0.1'') 3-mm ALMA observations of the CO(3-2) line emission in a z=3.07 bright gravitationally lensed Lyman Break Galaxy, LBG J213512.73-010143 (the `Cosmic Eye'). This LBG has previously been detected in CO(3-2) and CO(1-0) at lower resolution. Our previous 0.6'' resolution ALMA CO(3-2) reveals a molecular gas morphology roughly following the lensing arc, but unfortunately is too noisy (~3-sigma) to accurately map it back into the source plane reconstruction using the HST-based lensing model. More sensitive and higher resolution observations in an extended ALMA configuration of this magnified system will spatially resolve the line emission at ~0.1'' and allow us to map and dissect the molecular gas distribution on scales of ~200 pc (in the source plane). Not only will the proposed observations allow us to determine the size of the CO emitting region and the dynamical mass, but they will also enable us to unambiguously determine the nature of this system and the interplay/distribution of CO emission and star formation activity in the progenitor of a `normal' galaxy in the throes of formation. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2022-10-27T21:30:54.000 |
| 2728 | 2018.1.00007.S | 66 | An ACA Spectral Sampling Campaign of SN1996cr. | To date, the mm monitoring of the enigmatic SN1996cr, a type IIn SNe at 3.7 Mpc in the Circinus Galaxy, has been erratic and with inconsistent/poor sensitivity. We propose an ALMA ACA campaign to remedy this, capturing the current state of the mm synchrotron emission arising from the shocks, and placing a limit on extreme quantities of dust. Combined with existing and future radio observations, our data will probe whether there is any evident spectral curvature, which could provide insight on the cosmic ray acceleration and efficiency. Firm flux constraints in bands 7 and 8 will help understand the scope for future follow-up at high spatial resolution. | Supernovae (SN) ejecta | Stars and stellar evolution | 2020-09-14T19:50:31.000 |
| 2729 | 2016.2.00053.S | 302 | WISDOM: From Small-Scale Structure to Galaxy-Scale Processes | Observations of molecular gas at both GMC and galactic scales in external galaxies are key to understanding the molecular cloud (MC) formation and the relation of small-scale structures to galaxy-scale processes. Although the exquisite resolution of ALMA allows us to effortlessly resolve individual GMCs in nearby galaxies, we have demonstrated a need for low-resolution ALMA maps in GMC studies to allow complete flux recovery and total mass measurement of cold gas. We aim to 1) accurately measure MC (including low-mass MCs) properties and study their relations to galactic environment, using a high-sensitivity map combining high- and low-resolution observations; 2) investigate Larson's relations in external galaxies; 3) study star formation relations from large galactic-scales to small GMC-scales; and 4) determine the conversion factor between CO flux and H2 mass using the virial mass method. Our work will use a uniform methodology to perform a comprehensive analysis of MCs properties across different galaxy environments. Our aim is to address multiple key open issues regarding MC formation/evolution and their relationship to the wider galactic environments. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2018-08-21T14:46:58.000 |
| 2730 | 2016.1.00567.S | 304 | When the Very Large Telescope is not large enough: spectrosopic identification of z~4 massive galaxies | We have recently built the ALMA Redshift 4 Survey, 870um observations of 100 galaxies at z=4, selected solely from their stellar mass in the deep CANDELS fields. These exquisite data allowed us to constrain the star formation mode of massive galaxies in the early Universe, and we will further investigate their dust attenuation properties and star formation geometry in future works. However, the main source of uncertainty is the derivation of the redshifts, based on the UV-to-NIR broadband photometry. The ALMA detections show very red SEDs, and many lack a strong break from which the redshift can be reliably guessed. NIR spectroscopy with the VLT (KMOS) was obtained with 6h on-source integration: no emission line was found. At this stage, the only way to obtain the spectroscopic identification of these objects is to target sub-mm lines, and ALMA is the most efficient tool to achieve this. As part of a pilot program, we propose here to observe 3 of our brightest galaxies and scan CO lines with an original and efficient setup to unambiguously determine their redshifts. In addition to its obvious legacy value, this program will pave the way for future more extensive campaigns. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2018-01-20T03:59:30.000 |
| 2731 | 2013.1.01110.S | 1 | Probing the origin of flux-ratio anomalies in quadruple lenses with ALMA | The number of satellite galaxies in our Galaxy is by far smaller than expected from theory. This is so-called the 'missing satellite problem'. Quadruple lens systems showing the anomalies in their flux ratios of lensed images have long been thought to be caused by such small-scale CDM subhalos with a mass of ~10^(8-9) solar mass residing in a host lensing galaxy. However, recent theoretical work provided an alternative mechanism for the origin of the anomalies caused by mini-structures (mini-halos/voids) in intergalactic space with mass scales of < 10^8 solar mass. In order to distinguish between these two scenarios, we propose to carry out high-resolution observations of dust continuum emission from the region surrounding a QSO that shows anomalous flux ratios. If mini-structures in the line-of-sight are indeed the main cause of the anomalies, then this will set important constraints on the abundance of CDM subhalos in a lensing galaxy, which eventually limits the nature of dark matter itself. Based on the flux measurement of lensed images with unprecedented accuracy O(0.01) mJy on sub-arcsec scales, ALMA will provide us fundamental information on the nature of dark matter. | Gravitational lenses | Cosmology | 3000-01-01T00:00:00.000 |
| 2732 | 2021.2.00181.S | 31 | Tracing the UV Field Across Star-forming Cloud B35a | Constraining the physical conditions within molecular clouds plays a key role in understanding how the gas and ice chemistry in their daughter star-forming regions will evolve. A key underconstrained physical condition in low-mass star-formation regions of B35A is the UV field, G_0. In this study, the CN/HCN ratio will be calculated to constrain these across the B35A star-forming core allowing insight into the effects of UV irradiation on the local chemistry within a molecular outflow from the central IRAS 05417+0907 young stellar object (YSO) and the cloud's northern edge's photo-dissociation region (PDR). The physical constraints determined by these gas-phase data will be used to inform future chemical models of gas-phase and solid-state of molecular clouds aiding to unravel their synergies as we move into the JWST era. | Outflows, jets and ionized winds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2024-09-07T14:10:56.000 |
| 2733 | 2021.1.01056.S | 63 | The chemical evolution of complex organic molecules from hot core to disk in S255IR NIRS3 | Although the chemical richness and complexity of hot cores have been largely studied, those of MYSO disks have never been explored because the detection of the MYSO disks is rare. In addition, the accretion process in MYSOs over the scale from thousands to hundreds AU is still poorly understood both in the physical and chemical aspects. Recently, an important laboratory to explore these unknowns has been found; a disk-mediated accretion burst event has been detected for the first time toward a MYSO, S255IR NIRS3, which harbors a chemically rich hot core and a rotating disk. Taking advantage of this unique situation of S255IR NIRS3, we aim to investigate the ice composition from the hot core to the disk. The kinematics traced by optically thin COMs lines will allow us to disentangle the disk from the hot core. The distinguished properties of various COMs in disk and hot core will provide a special opportunity to self-consistently study the evolution of ice composition in the disk material after being accreted from the inner envelope. Therefore, we propose the spectral scan observation in two configurations. To complete the observations, we resubmit the ongoing Cycle 7 program. | High-mass star formation, Astrochemistry | ISM and star formation | 2022-12-21T05:45:53.000 |
| 2734 | 2021.1.00815.S | 1116 | Testing structure formation, quenching and gas accretion models with a sample of 36 groups/clusters at 2<z<3.5 | We propose to spectroscopically confirm a homogeneous sample of 36 Herschel/SPIRE-selected starbursting massive galaxy cluster/group candidates at z=2-3.5 via ALMA redshift scans for CO[5-4] in band4/5. Targets are selected as SPIRE-350um peakers associated with prominent overdensities of massive high-redshift galaxies, and are from 3 widely separated fields covering 20 sq.deg. Pilot projects already demonstrated the efficiency of our approach: all 3 already-observed targets in COSMOS proved to be genuine groups/clusters at z=2.5-3.3. This ALMA program will observe 33 additional targets, increasing the confirmed number of structures by one order of magnitude, to enable first statistical constraints on the number density of forming galaxy groups/clusters at cosmic noon, and to open a new window on structure-formation at the peak epoch of cosmic assembly. The goals of this ambitious ALMA project will include measuring, as a function of dark matter halo mass and redshift, the distributions of total masses, SF rates and efficiencies, gas content, addressing key outstanding open questions on massive galaxies and structure formation and critically testing model predictions. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2023-08-21T22:29:38.000 |
| 2735 | 2023.1.01721.S | 0 | Unveiling the Early Stages of Massive Binary Formation with JWST | Most of massive stars are born in binary systems, therefore understanding massive binary formation is crucial for understanding massive star formation in general. Observational studies of massive forming binaries in the embedded phase are still very limited. JWST provides a new, unique window to study such systems. We propose JWST/NIRCam observations of two forming massive binaries, which are the closest-separation embedded-phase massive forming binaries identified to date. We aim to: 1) directly image the massive binaries utilizing the high resolution and sensitivity of JWST, and characterize the stellar properties and accretion status of individual members in these systems; 2) map the extended emissions of the outflow cavities, to determine the cavity geometries and heated dust distributions, especially in the innermost regions. 3) probe the low-mass young stellar objects (YSOs) forming along with the massive binaries. To achive the last goal, we also propose joint ALMA observation in 0.85 mm, to significantly improve the detection sensitivities of cold dust structures of the YSOs to achieve of a complete census of the low-mass YSO populations around these massive binaries. | High-mass star formation | ISM and star formation | 2024-11-22T11:29:38.000 |
| 2736 | 2018.1.00357.S | 31 | Magnetic field and emission mechanism in relativistic jets on sub-pc and kpc scales | We apply for 9 hours of ALMA time in full polarization mode to study the magnetic field structure and emission mechanisms of the nearest quasar 3C273 at both sub-pc and kpc-scales. We will observe the source at 2.1, 1.3, and 0.85mm to obtain total flux density and polarization continuum spectra of the source both in its unresolved core and the kpc-scale hotspot. Our pilot observations in Cycle 4 showed that there is a very large amount of Faraday rotation around the unresolved core of the source. The proposed observations will constrain the magnetoionic environment of the source by allowing us to distinguish between two plausible magnetic field configurations that are responsible for the Faraday rotation. We will also obtain, for the first time, polarization observations of the hotspot in 3C273 in the millimeter wavelengths, in order to study the magnetic field direction in comparison with radio and optical observations. The continuum mm-band spectrum along the kpc-scale jet will be crucial for determining the dominant emission mechanism and particle population, which affect the energetics of relativistic jets and their effect on the surrounding large-scale environment. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2020-02-19T00:00:00.000 |
| 2737 | 2018.1.00434.S | 94 | Measuring the star-forming gas reservoir of low-metallicity galaxies | Knowing how physical conditions and gas reservoirs affect star formation is of fundamental importance to understand galaxies near and far. The low metallicity regime (Z<0.2 solar metallicity) is particularly important for the high-redshift Universe and galaxy evolution, but it remains one of the least understood. This is mainly due to: 1) a lack of observations and 2) difficulties in interpreting the common tracers of the star-forming gas (dust and CO) because of large uncertainties in the conversion factors due to the presence of significant CO-dark gas. We propose deep ALMA CO(J=2-1) observations of 4 dwarf galaxies in the unexplored metallicity regime 0.1 solar to fill the observational hiatus. These ALMA data will be combined with our Herschel observations (including [CII]) to determine physical conditions and measure the full star-forming gas reservoir, i.e. both the CO-dark and CO-bright components. This will allow us for the first time to determine the star-formation efficiency and gas mass at 0.1 solar metallicity, and provide essential guidance for future observations (CO or other cooling lines). | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2020-07-14T02:20:00.000 |
| 2738 | 2015.1.01569.S | 5 | CO vs. CI in Henize 2-10 | An alternative tracer to CO of molecular gas that has received increasing attention in recent years is atomic carbon, CI. In particular, the ground-state fine-structure line CI at 492 GHz (hereafter, CI) has shown to be a good tracer of molecular gas in Galactic giant molecular clouds (GMCs), where a linear correlation has been found between CI and CO isotopologues. CI and CO have also been found to coexist in external galaxies (e.g., Gerin & Phillips 2000). Yet due to the poor transparency of the Earth's atmosphere at 492 GHz, studies of CI in external galaxies are rare. But with ALMA, this no longer need be the case. With ALMA's remarkable sensitivity, we can conduct extragalactic CI observations in a reasonable amount of time. In this proposal, we seek to observe the starburst dwarf galaxy He 2-10 in both CI and CO, with the objective of doing a detailed comparison of the molecular tracers. We expect to identify at least ~20 CO and CI GMCs; this would be the largest systematic study, to date, which compares CO and CI in the same dwarf galaxy on a systematic basis. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2017-09-14T22:39:02.000 |
| 2739 | 2018.1.00815.S | 30 | The controversy on the origin of Earth Oceans: addressing the D/H ratio in comet 46P/Wirtanen | Comets provide a record of the chemistry of the primitive solar nebula, and thereby important clues on the early evolution of the Solar Nebula. Isotopic ratios are important diagnostics because isotopic fractionation is very sensitive to chemical and physical conditions. Measuring the D/H ratio in water in a significant sample of comets is very important to understand the history of water in the Solar System. Recent measurements with Herschel and Rosetta revealed an unexpected diversity that needs to be confirmed and investigated. This proposal is aimed at exploring this diversity of the HDO/H2O ratio in comets to understand deuterium enrichments in primitive Solar System objects. Comet 46P/Wirtanen is making the most favourable apparition of a Jupiter family comet when it will pass only 0.08 AU from the Earth in December 2018. We wish to take advantage of this exceptional opportunity to measure the D/H ratio in the water of comet 46P using the high sensitivity of the ACA/TP facility of ALMA. | Solar system - Comets | Solar system | 2021-02-01T00:00:00.000 |
| 2740 | 2024.1.00968.S | 0 | The AGN-ISM interplay in the molecular disk of the iconic Seyfert II galaxy -- Circinus | We propose Band-6 12m+7m+TP observations at 1.3"-resolution (25 pc) of the CO(2-1) line emission in the very nearby Seyfert II galaxy, Circinus. Despite its iconic status, only shallow ACA maps of the molecular disk exist. The proposed observations will deliver the first high-fidelity, cloud-scale resolution image of the distribution and kinematics of the molecular gas over the R ~4 kpc molecular disk. We will catalog and compare the properties of molecular clouds (mass, size, velocity dispersion, virial factor, SF depletion time,...) across the different environments of Circinus. We will combine these measurements with a multiwavelength suite of ancillary data from public archives to conduct several experiments focused on the impact of AGN feedback (1) on GMC properties, (2) on the HI-to-H2 transition, and (3) the interplay between the bar-driven inflow and AGN-driven outflow. For a modest time investment (~3 hrs of 12m array time), the observations will deliver a valuable legacy dataset that enables several tests of general interest for star formation and galaxy evolution studies. | Spiral galaxies | Local Universe | 2025-11-15T22:25:51.000 |
| 2741 | 2017.1.00685.S | 14 | In search of the high HCN/HCO+ ratio origin in AGNs: SiO imagings of Seyfert galaxies down to 15-30 pc scales | The origin of HCN enhancement in AGNs, which can be seen in high HCN/HCO+ ratio, is still far from well understood. Now ALMA reveals much higher HCN/HCO+ ratios found in the circumnuclear disks (CNDs) rather than the exact AGN positions, which raises a scenario that HCN is enhanced by mechanical heating such as shock of jet/outflow from AGNs (MH scenario). The immediate objective is thus to verify the MH scenario by revealing the distribution of shocked gas at high spatial resolution down to sub-CND scale. Here we propose unprecedented 15-30 pc resolution imagings of SiO J=6-5 line, a good shock tracer, toward the two distinct CNDs of nearby Seyfert galaxy NGC 1068 and NGC 1097. We aim to achieve the following science goals, which will be observational evidence to verify the MH scenario: 1. Do SiO and HCN arise from the same regions in the CNDs? --- We will confirm whether the distribution of SiO and HCN have spatial correlation or not, regardless of AGN activities of these galaxies. 2. If so, are SiO and HCN really enhanced? --- We will then compare SiO/H13CO+ and H13CN/H13CO+ ratios to confirm whether these are enhanced at the same region found the above science goal. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2020-02-20T01:57:17.000 |
| 2742 | 2019.1.01714.S | 15 | Magnetic Fields in High-Mass Prestellar Cores: The Missing Piece of the Puzzle | Magnetic fields (B-fields), along with turbulence and gravity, may be the key mechanisms governing the formation of high-mass stars. While turbulence and gravity have long been studied in detail, the particular role and overall importance of B-fields are yet undetermined. High-mass prestellar cores (HMPSCs; >30 M_sun) are likely precursors to high-mass stars and are predicted to be in vastly different dynamical states by different high-mass star formation theories. Only a handful of HMPSC candidates exist in the literature, and measurements of their B-fields are virtually nonexistent. The final piece of the energy puzzle thus lies in determining the relative strength of the B-field in these cores. We present a unique pilot study estimating the total energy balance in an HMPSC candidate and find relatively strong B-fields. Building upon these results, we propose to expand our sample to include 6 recently discovered HMPSC candidates. Using dust polarization (250 GHz) and line emission, we aim to investigate B-field morphologies and estimate field strengths to definitively test high-mass star formation theories. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-03-31T08:49:47.000 |
| 2743 | 2021.1.01216.S | 395 | Infall in Class II Disks: A Chemical Fountain of Youth? | Chemical surveys of younger, embedded Class I disks and more evolved Class II disks reveal marked differences, implying that planets forming at these two stages would likely have distinct compositional signatures. However, Class II disk surveys have preferentially targeted isolated systems, whereas some Class II disks have now been shown to be associated with remnant envelope and/or filamentary structures. This raises the question of to what extent continued infall in Class II disks can act as a chemical ``fountain of youth,'' imparting characteristics more similar to Class I disks compared to isolated Class II disks. We therefore propose to undertake a pilot survey of five Class II disks showing evidence of interacting with envelope or nearby cloud material in order to determine if and how their composition varies from isolated Class II disks. We target species probing chemical differentiation between the infalling material and the disk, CO depletion, UV-mediated chemistry, and the organic reservoir. This survey will advance our understanding of how disk environments influence the range of compositions possible during planet formation. | Disks around low-mass stars | Disks and planet formation | 2023-02-17T22:57:19.000 |
| 2744 | 2012.A.00033.S | 3 | Revealing the chemical evolution of sun-grazing comet C/2012 S1 (ISON) | Cometary ices contain pristine material from the formation of the solar system, and studies of their composition provide unique information regarding the physical and chemical conditions of the early Solar Nebula. Use of gas-phase coma observations as probes of cometary ices requires a complete understanding of the gas-release mechanisms, but previous observations have been unable to ascertain the precise origin of fundamental coma species CO, H2CO, HCN, HNC and CS, and details regarding their possible formation in the coma are not well understood. We propose to obtain spectrally and spatially-resolved sub-mm emission maps of CO, H2CO, HCN, HNC, CH3OH and CS in the coma of comet C/2012 S1 (ISON), which will reach a heliocentric distance of 0.012 AU on November 28th 2013. The proposed 3D maps of this bright comet will provide critical tests of release models for the species of interest. Hypothesised extended sources of CO, H2CO, HCN, HNC and CS will be evaluated, and comparison of HCN, CO, and CH3OH distributions will test whether HCN is associated with the polar or the apolar gases. Observations conducted before, during and after perihelion will probe the chemical evolution of this sun-grazing comet, and the effects of intense radiation on the nuclear ices and molecular sources will be investigated. These observations also provide the exciting possibility of obtaining the first-ever images of a cometary nucleus undergoing breakup/destruction. The proposing team is composed of scientists from the North American, European, East Asian and Chilean ALMA executives. | Solar system - Comets | Solar system | 2015-01-24T16:24:55.000 |
| 2745 | 2015.1.01163.S | 27 | Measuring the luminosity of massive protostars via their millimeter brightness temperature | A major hurdle to improving our understanding of the process of massive star formation is the inability to determine the luminosity of individual massive protostars in deeply-embedded protoclusters. The problem is caused by the lack of high-resolution telescopes in the mid- to far-infrared that cover the peak of the Planck curve. Without being able to apportion the total luminosity among the cluster members, it is impossible to construct luminosity functions which might shed light on how clusters evolve. The advent of ALMA's long baseline capability offers a new technique for measuring the luminosity of compact millimeter sources via their brightness temperature. The high dust column density around a massive protostar makes it optically-thick to radiation shortward of about 1 mm wavelength. By measuring the angular size and brightness temperature at a few wavelengths near unity opacity, one can compute a luminosity estimate from the Stefan-Boltzmann law. By observing with 0.07 arcsecond (130AU) resolution in Band 4, 6 and 8, we propose to test this technique on several protostars in the M17 UC1-IRS5 region whose 1-20 micron luminosities have recently been measured on the VLT. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2017-09-30T00:00:00.000 |
| 2746 | 2015.1.01602.S | 2 | Where are the missing stars? - Quasar hosts with extreme stellar mass deficit at z ~ 3 and the co-evolution picture | The physical mechanism of the blackhole-host galaxy co-evolution is one of the most important questions in astrophysics. We propose to observe a unique sample of quasars with extreme stellar mass (M*) deficit compared to the measured blackhole (BH) mass at z ~ 3, the peak epoch of the active galactic nucleus accretion history. These quasars are drawn from 70 quasars at z ~ 3 whose host are studied with Subaru AO-assisted imaging. While we detected stellar components for most, the quasars proposed here have >10x deficit in bulge M* compared to the BH mass, which can serve as a testbed for the co-evolution mechanism. We expect a substantial amount of gas to be present in these hosts but not yet formed enough stars for a massive host galaxy, and hence the extreme CO luminosities that will allow spatially and dynamically resolved CO lines observations. Together with our sensitive M* limits, we will use the gas and dynamical mass estimates to either confirm that these hosts will be able to move onto the well established local BH-host scaling relations, or if the gas content is too low, indicating that mergers and/or gas inflows have a major impact on their evolution. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-01-20T10:04:43.000 |
| 2747 | 2024.1.01065.S | 0 | SYMPHANY- SYnergy of Molecular PHase And Neutral hYdrogen in galaxies in A2626 | We propose the SYMPHANY survey to image the morphologies and kinematics of the molecular gas disks in 27 galaxies in A2626 at z=0.0545 with the CO(2-1) line at a resolution of 1.4kpc by 20km/s and a surface density sensitivity of 5Msun/pc^2. We will investigate the efficiency of gas removal mechanisms that act on a galaxy's multi-phase ISM, resulting in the quenching of its star formation (SF) activity as it falls into a dense cluster environment. The spatial and velocity resolution of the ALMA data cubes are crucially complementary to existing MeerKAT HI, INT H-alpha imaging data, along with MeerKAT 1.4GHz, AstroSAT/GALEX UV and WISE 22micron images to characterize ongoing SF activity and planned WEAVE MOS/mIFU spectroscopy to yield recent SF histories. The sample size allows to study trends in the distribution and kinematics of the multi-phase ISM with galaxy mass, SF activity, HI deficiency, local environment etc. Comparing the multi-phase ISM and SF activity of galaxies in A2626 with that of galaxies in the equally massive Virgo and more relaxed Fornax clusters will shed light on the influence of cluster mass and dynamical state on the evolution of their constituent galaxies. | Spiral galaxies, Surveys of galaxies | Local Universe | 3000-01-01T00:00:00.000 |
| 2748 | 2016.1.00606.S | 18 | What is the Origin of the Spiral Structure in the Protoplanetary Disk around Elias 2-27? | Planets form in disks of gas and dust that orbit young stars. In these protoplanetary disks, gravitational forces can excite spiral density waves of different amplitude, pitch angle, location, and number, depending on the driving mechanism. Recent 1.3 mm ALMA observations have revealed a pair of symmetric and trailing spiral arms in the disk around the embedded pre-main sequence star Elias 2-27. These arms extend to the disk outer regions and can be traced down to the disk midplane, while inwards of the arms, a gap in the disk emission is observed. To understand the origin of these spirals, we propose new ALMA observations in Band 3 and Band 7 at 0.2'' resolution that will trace both the dust and gas component in the disk. By constraining the spectral index of the dust continuum emission (Goal A) and determining the contrast of these spiral arms in the gas component of the disk (Goal B), we aim to discern what is the origin of these spiral structures and provide a new benchmark for theoretical simulations of spiral density waves in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2018-09-11T19:01:34.000 |
| 2749 | 2024.1.01001.L | 0 | A Survey of Planet-Forming Chemistry in the Precursor Environments of Giant Planets | Protoplanetary disks are precursors to planetary systems. Disks around Herbig stars (young A/B/F-type stars) are known prime sites for studying the chemistry of giant planet formation. However, there has yet to be a large, uniform survey of Herbig disk chemistry across a variety of disks and molecules - and, given the extreme disk environments of Herbig stars, lower-mass stars cannot be used as proxies. We propose to survey planet-forming chemistry around 20 Herbig disks, 40% of known Herbig disks within 320 pc. We target tracers of *) ionization, relating to the growth and movement of planet-forming material; and *) cold chemistry, controlling the gas vs ice distribution and thus the composition of forming planets. We also cover a wealth of legacy planet-forming chemistry, including CO gas mass estimators; sulfur chemistry and probes of C/O ratios; and tracers of shock and planetary activity in disks. Ultimately, we will: 1) characterize how the extreme environments of Herbigs manifest in their chemistry; 2) compare Herbig disk chemistry to that of lower-mass stars; and 3) constrain how the compositions of evolved A/B/F-star planetary systems, like the iconic HR 8799, come to be. | Disks around high-mass stars | Disks and planet formation | 2025-11-04T20:03:35.000 |
| 2750 | 2018.1.01149.S | 76 | Measuring the Emission of Stellar Atmospheres at Submillimeter/Millimeter Wavelengths | Our understanding of stellar atmospheres and our ability to infer architectures of extrasolar planetary systems rely on understanding the emission of stars at millimeter wavelengths. We propose to use ALMA to determine the stellar emission of Sirius A in Bands 4 - 5, gamma Lep and gamma Vir in Bands 6 - 7, and Fomalhaut in Band 4. The proposed observations are a continuation of a partially observed Cycle 5 project and will be used to: (1) determine submillimeter/millimeter intrinsic stellar fluxes for the sampled A and F stars; and to (2) evaluate potential variability in their stellar emission. These observations are fundamental to testing stellar atmosphere models, are essential for evaluating the occurrence rate of stellar excess (used to infer the presence of unresolved dust), and are required for determining the dust spectral indices at the proposed wavelengths. | Debris disks, Disks around high-mass stars | Disks and planet formation | 2020-07-10T22:09:09.000 |
| 2751 | 2017.1.01125.S | 2 | Extreme scattering due to cometary globules | Intra-day variability (IDV) and extreme scattering events (ESEs) occur when galactic screens of ionized gas intervene between Earth and a distant point-like radio emitter, causing refractive scattering. We have recently discovered that these phenomena occur in very close proximity to local, hot stars, and that the scattering plasma is found in radial filaments. We expect that these filaments are primarily made up of cold gas with a thin skin of plasma, allowing these scattering screens to be long-lived. These proposed observations aim to observe CO emission from this cold gas surrounding the nearby star Spica, towards a quasar currently displaying large, rapid amplitude modulation. A detection here will greatly improve our understanding of star formation and galaxy dynamics, as these molecular clouds may make up a large fraction of galactic dark matter. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-06-30T00:00:00.000 |
| 2752 | 2012.1.00346.S | 2 | Star Formation via Infall: A Definitive Test by ALMA | We propose to test the fundamental assumption that stars form by infall of gas. We will use the unprecedented sensitivity and resolution of ALMA to detect redshifted absorption from infalling gas against the continuum emission of the circumstellar disk. | Low-mass star formation | ISM and star formation | 2015-06-18T15:28:20.000 |
| 2753 | 2018.1.00088.S | 99 | Observing i process nucleosynthesis products in V4334 Sgr | In many instances of stellar evolution, especially at very low metallicity, H-combustion events (triggering the i process) are encountered. Exactly how these stars deviate from normal evolution is not clear. This is however important for modeling the evolution of the first generation of stars in the Universe. A direct comparison of models with observations can only be done in the case of Sakurai's object (V4334 Sgr), a post-AGB star which recently experienced a very late thermal pulse. The mixing of proton rich material into the 12C-rich He-shell induced exotic neutron-capture nucleosynthesis. The high efficiency of this process, together with the immediate ejection of the burning products, offers a unique possibility to study the i process. This can be done by studying the carbon isotopic composition through observations of isotopologues of carbon-bearing molecules. In particular we propose to derive the ratio 12C:13C:14C, which (apart from 4He, 16O, and 14N) are the three most abundant isotopes in the ejecta. The proposed observations will provide strong constraints on the i process. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2020-08-16T02:08:09.000 |
| 2754 | 2016.1.00330.S | 17 | Detailed Gas and Dust Physics in "Normal" Galaxies and Starbursts at z>5 | Cosmological simulations suggest that massive galaxies formed in the densest regions in the early universe through hierarchical buildup, predicting the existence of massive protoclusters of intensely star-forming galaxies at high redshift. We have identified such a unique region within ~1 billion years of the Big Bang, hosting an extreme starburst and 14 normal star-forming galaxies. Advancing upon our highly successful efforts related to this region in cycles 0-3, we here propose to image and model the morphology and dynamical structure of the gas and dust in a "normal" star-forming protocluster member galaxy at z=5.3 down to individual star-forming clumps on 500pc scales, to study the dust in the hot, compact nucleus of the most distant unlensed starburst known (i.e., not limited by lens modeling accuracy) at rest-frame ~70um at 250pc resolution, and to constrain the highly-excited gas from this nucleus by detecting the CO J=13/14 lines. This unprecedented study will critically constrain the dynamical origin of star formation activity in normal z>5 galaxies, and the extreme properties of starburst nuclei at such early epochs, which dwarf any galaxies in the present-day universe. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-04-03T16:49:18.000 |
| 2755 | 2019.1.00437.S | 108 | Characterizing intermediate- to high-mass disk candidates with multi-wavelength millimeter and mid-IR observations | We will address two fundamental questions in the early phase of intermediate- to high-mass star formation: how does the structure of cold dust compare to that of warm thermal emission, and what are the properties of central disk-like structures surrounding some of the most luminous young stellar objects (YSOs)? We have observed a sample of intermediate- to high-mass YSOs at tens of milli-arcsecond resolution in the mid-IR with the VLTI/MIDI instrument and were able to resolve the innermost warm and hot dusty structures. We wish to complement our mid-IR observations for a subsample of six best disk candidates at comparable milli-arcsecond resolution with ALMA at 1.3 mm. With high angular resolution of 0.03'' (~100 au) we will resolve and characterize the properties of the candidate disks. Covering scales up to 1.7'' (few thousand au) we will trace the flow of gas in the transition region between envelopes and the inner disks, examine thermal feedback from embedded protostars, and observe the ejection point and direction of outflows. We will connect the different phases of thermal dust and gas emission for this unique sample, currently in queue for observations with VLTI/MATISSE. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2022-08-02T21:57:37.000 |
| 2756 | 2016.1.00843.S | 34 | CO and AGN feedback in massive galaxies | We propose to measure the molecular gas content in three massive elliptical galaxies at the centers of nearby, X-ray bright groups known to contain kpc-extended dust and cooler, multiphase gas. Many recent observational and theoretical studies of the centers of hot gas atmospheres in galaxy groups and clusters conclude that multiphase gas is evidence of non-linear radiative cooling to low temperature. Such cooling is thought to produce molecular gas visible in CO, but so far CO has been detected in only one galaxy/group, NGC5044, during ALMA cycle 0. Here we propose to test this multiphase cooling hypothesis by observing the cores of three nearby group-centered giant elliptical galaxies, all similar to NGC5044. This test is best done with galaxy groups, not clusters, because of their simplicity and proximity. In short: our ALMA observations will reveal or constrain the physical nature of the cooling-accretion-feedback cycle driven by massive central black holes in elliptical galaxies. | Outflows, jets, feedback, Early-type galaxies | Active galaxies | 2018-03-30T14:02:33.000 |
| 2757 | 2011.0.00120.S | 0 | The earliest stages of star and planet formation | Pre-stellar cores (PSC) represent the initial conditions for the process of star and planet formation. Although their overall structure is well known, the central few thousand AU are completely unexplored because high density tracers are heavily frozen onto dust grains. The best tracers of regions with densities > 10^6 cm^{-3} (and temperatures < 7 K) are light molecular ions, in particular the ground state transition of ortho-H2D+ at 372 GHz, observable with ALMA Early Science in Band 7. ALMA Cycle 0 offers the first and unique opportunity to peer into the PSC nucleus and study the birthplace of stars and protoplanetary disks at size scales of a few hundred AU. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2013-11-27T08:27:00.000 |
| 2758 | 2023.1.01640.S | 0 | Spectral line survey toward a hot molecular core in the extreme outer Galaxy | Because cosmic metallicity is increasing in time with the evolution of our universe, understanding the star formation and interstellar medium at low metallicity is crucial to unveil physical and chemical processes in the past Galactic environment. The outer part of our Galaxy is one of the excellent laboratories for such studies thanks to its low-metallicity environment. The recent discovery of a hot molecular core located at the galactocentric distance of 19 kpc has suggested that a great molecular complexity exists even in a primordial low-metallicity environment of the outer Galaxy. However, since only limited spectral regions were observed so far, the detailed chemical compositions of the source still remain to be investigated. We here propose an unbiased spectral line survey in 329-360 GHz toward this hot core, WB89-789 SMM1. A goal of this first line survey for the outer Galaxy hot core is to establish a comprehensive view of chemical compositions of a Galactic low-metallicity star-forming core with unprecedented molecular line datasets and to understand them in relation to the characteristic metallicity environment. | Astrochemistry | ISM and star formation | 2025-09-24T00:22:15.000 |
| 2759 | 2023.1.00271.S | 0 | The pulsar-disk interaction in the gamma-ray binary PSR B1259-63/LS 2883 | We propose to observe the periastron passage of the PSR B1259-63/LS 2883 system with ALMA for the first time. This gamma-ray binary consists of a pulsar and a massive star with a circumstellar disk, and has an orbital period of 3.4 yr. This binary have shown violent multi-wavelength flux changes around periastron, which are attributed to the interaction between the pulsar and the disk. While ALMA has not observed this binary around periastron, previous observations away from periastron suggested that emissions in ALMA Bands 3 and 7 come from the pulsar and the disk, respectively. Thus, by observing the binary around the next periastron passage (June 30, 2024) with ALMA in Bands 3/6/7, we can reveal the pulsar-disk interaction. In particular, we study the process of disk disruption by the pulsar, which is likely to be associated with the ejection of fast-moving X-ray objects and gamma-ray flares. We also compare the ALMA data with multi-wavelength data (X-ray including XRISM, infrared, low-frequency radio) and the results of numerical simulations to better understand the pulsar-disk interaction. | Pulsars and neutron stars | Stars and stellar evolution | 2025-08-08T18:21:40.000 |
| 2760 | 2013.1.00742.S | 2 | A comprehensive view of the role of molecular gas content in main-sequence galaxies at z>2 | We propose to conduct deep CO line observations of star-forming galaxies at z=2.5 in an exceptionally unique field, CANDELS-UDS-SXDF. Two pointings include 12 main-sequence galaxies at z=2.5 which are selected by our narrow-band Ha emitters survey with Subaru Telescope. They are clustered and embedded in a filamentary structure traced by far-infrared images (SPIRE/AzTEC), suggesting the presence of dusty star-forming populations. Therefore, the targets are very suitable for cycle-2 capabilities in terms of observational efficiency and feasibility. Moreover, we have been accumulating extensive datasets in this field, including existing HST images , KMOS multi-IFU data, and ALMA 1.1mm imaging. The proposed observations allow us to exploit the molecular gas content of galaxies to lower stellar mass for the first time. Our goals are to derive their gas fraction and depletion timescale, and relate them with stellar mass, specific SFR, mode of star formation, morphology, and environment. This will give us critical information to characterize the variation of star formation activities with respect to the main-sequence on the SFR-M* plane and address the origin of the main-sequence. | Starburst galaxies | Active galaxies | 2016-12-15T20:31:45.000 |
| 2761 | 2015.1.01592.S | 19 | Unveiling the nature of an extremely low-luminosity, red YSO detected in the ACA imaging of rho Oph-C: forming phase of very low-mass brown dwarf at the planetary border? | The formation of low-mass substellar objects (low-mass brown dwarfs, BDs, near the planetary border and planetary mass objects, PMOs) is one of fundamental unresolved problems in star and planet formation. Observations and theories suggest that such objects are also formed in isolated cores in the same manner as stars. However, the clear evidence for isolated proto-BDs/PMOs is lacking. This prevents us from understanding the formation of stars and substellar objects by means of some unified scheme such as cloud fragmentation, and also understanding basic physics undelaying the link between IMF and CMF, especially near the low-mass end. Our recent cyc-2 observations, aiming at revealing the low-mass end of CMF in the rho Ophiuchus regio, detected 1.3 mm emission toward an extremely low-luminosity Flat/Class-II YSO. Analyzed SED suggests that it would be a candidate proto-BD or proto-PMO still embedded in a very low-mass envelope/core. Another interpretation is a very young BD/PMO accompanied by highly flared disk. We propose ALMA band-6 follow-up observations to unveil the nature of source and investigate the formation of substellar objects together with the cyc-2 observations. | Low-mass star formation | ISM and star formation | 2017-11-15T06:19:21.000 |
| 2762 | 2017.1.01310.S | 15 | Disentangle the Origins of Polarization in Millimeter Wavelengths for the Youngest Protostellar Systems | In cycle 4 we have carried out polarimetric observations toward youngest protostellar systems with an extended disk feature but in a large-scale magnetic field aligned to the bipolar outflow, which provides efficient magnetic braking. The excellent data recently delivered show that magnetic field directions dramatically shift perpendicular to the bipolar outflow at the center, which means that there are other mechanisms to allow early disk formation even in the primordial field for a strong magnetic braking. However, these interpretations are based on the assumption that polarization of millimeter wavelengths is mainly by dust grains aligned in magnetic fields. Recently, it has been found that polarization even in millimeter wavelengths can also be caused by self-scattering and radiation alignment of grains. In order to study the polarization origins and magnetic fields of protostellar systems we propose for ALMA polarimetric observations in Band 3, complementary to our beautiful Band 6 data. In addition, these data sets will provide the best and unique chances to study grain size distributions of protostellar systems in detail. | Low-mass star formation | ISM and star formation | 2019-11-27T19:28:39.000 |
| 2763 | 2022.1.00860.S | 36 | Probing Multiphase CGM in SMM J02399 | Previous observations of Ly, [N II]122, CO strongly suggest the existence of a cold, dense and enriched circum-galactic medium (CGM) composed of neutral, ionized and molecular gas, extending up to 100 kpc scale surrounding SMM J02399, potentially fueling the strong star formation and AGN activity in the central galaxies. However, the mass and physical conditions in the large-scale CGM still remain unconstrained. Here we propose to utilize neutral gas tracer [C II], ionized gas tracer [N II]122, molecular gas tracer [C I]609 and CO(5-4) to map and characterize the multiphase gas in CGM. We aim to (1) confirm the extended nature of [N II]122, CO, [C I] and [C II] from CGM; (2) map ionized and neutral and molecular gas in CGM as a complete multiphase view of the cool phase gas in CGM; (3) constrain multiple physical properties in CGM; (4) derive the scaling relation between Ly and [C II] to assess the powering/excitation mechanism of the former. A successful detection will answer the key questions including the physical condition of the cold gas in CGM, the mass exchange between CGM and central galaxies, and the evolutionary effect of CGM in fueling star-formation and AGN. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-10-11T11:56:53.000 |
| 2764 | 2018.1.01254.S | 217 | Completing the SPT+ALMA Redshift Survey | Recent ground and space-based multi wavelength (sub)millimeter surveys have discovered a large number of strongly lensed, ultra-bright sub-mm galaxies (SMGs). From these surveys, particularly the 2500 square degree South Pole Telescope (SPT) survey, we have constructed a catalog of these 81 high-redshift SMGs. Blind scans using ALMA's 3mm line capabilities have proven useful for determining spectroscopic redshifts. Previous ALMA proposals have enabled us to determine the spectroscopic redshifts for 76 of these sources using ALMA's 3mm line scans. In this proposal, we present the last 13 sources for which we only detect a single line feature. In these cases, we can only narrow the line identification to two plausible CO transitions, which leads to ambiguity in our results. We therefore request an additional 7.42 hours of observing time in order detect a second CO line in band 4, which would confirm their redshift. Obtaining robust redshifts for the complete catalog of SPT sources will enable further study into star formation rate for this highly elusive population of galaxies, and further our understanding of galaxy evolution. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2020-01-18T01:04:18.000 |
| 2765 | 2021.1.01350.S | 17 | Extreme Super-Eddington Star Formation in a Quasar Host at z~7? | The common framework of galaxy-black hole co-evolution postulates that early black hole accretion events and intense starbursts occur simultaneously at early epochs to explain the observed black hole - bulge stellar mass relation. High-redshift quasars are perfect to probe this paradigm: they host rapidly growing supermassive black holes accreting at or near the Eddington rate that reside in host galaxies forming stars at rates rivaling the brightest local ultraluminous Infrared Galaxies. ALMA Band 6 observations at unprecedented resolution (0.035") show that a quasar at z=6.9, J2348-3054, has a surface brightness and implied star formation rate surface density an order of magnitude higher than any local ULIRG or high-redshift quasar, violating the theoretical prediction of Eddington-limited "maximum starbursts". This programme aims to confirm the nature of this extreme starburst in J2348-3054 by constraining the dust temperature at +-3 K with ALMA Band 8/9 at a spatial resolution of 200 pc. Resolving the dust properties in J2348-3054 at 200 pc will shed light on the link between the central AGN and the most extreme starburst region known in the distant and local Universe. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-12-30T00:00:00.000 |
| 2766 | 2015.1.01590.S | 68 | Constraining the molecular gas content of normal star-forming galaxies at 3<z<3.5 | The goal of this proposal is to unveil the nature of 5 normal main sequence star-forming galaxies at 3 | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2017-08-10T14:21:58.000 |
| 2767 | 2023.1.01211.S | 0 | Imaging the circumplanetary disk around HD 169142 b | A forming planet embedded in the disk around HD 169142 was recently detected in VLT/SPHERE near-infrared observations and overlaps with a non-Keplerian kinematic signature in the gas. We propose to study the circumplanetary disk that enshrouds the planet utilizing sub-mm continuum observations. We request a spatial resolution of 0.05" to image the continuum in band 9. The high angular resolution would resolve the circumplanetary disk from circumstellar disk material, enable analysis of its physical properties and independently confirm a new directly imaged protoplanet. | Disks around high-mass stars, Exo-planets | Disks and planet formation | 2025-07-22T19:46:08.000 |
| 2768 | 2015.1.00971.S | 10 | Mapping the Molecular Gas in NGC 5813 | We propose to map the molecular gas and its dynamics through CO(2-1) line flux measurements in the core of the galaxy group NGC 5813, with an angular resolution of 1.5". This group shows a unique X-ray morphology, with three pairs of collinear cavities, each pair associated with an elliptical cocoon outburst shock, from three distinct outbursts of the central AGN. It is therefore extremely well suited to the study of AGN feedback and the outburst history of the AGN. By comparing the proposed ALMA observations with our very deep Chandra observations we will trace the cooling gas over six orders of magnitude in temperature, from the X-ray, to the H-alpha emitting, to the molecular phase on arcseond scales. By determining the dynamics of the molecular gas, we will also compare hot gas versus cold gas fueling rates for the central AGN, which in turn can be compared with the long term AGN power output thanks to the unique X-ray morphology of this system. Finally, from the dynamics of the molecular gas we will evaluate whether the gas is pushed out along with the X-ray gas by the expanding cavities, lifted by/infalls along the H-alpha filaments, or both. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2017-09-30T16:14:00.000 |
| 2769 | 2019.1.00736.S | 10 | Mapping the youngest pulsar wind nebula in the Galaxy | Pulsar wind nebulae (PWNe) are Nature's best particle acceleration laboratories. Young pulsars and young PWNe are very dynamic and can show evolutionary effects on timescales of a few years. Most young PWNe have been discovered and studied in X-rays, where the fluxes and spectral parameters of distinct jet and torus structures constrain the properties of the highly-relativistic pulsar wind particles, the acceleration mechanisms, and the geometry of the pulsar. Mm observations of PWNe can provide additional constraints, e.g., on the energy spectrum of the injected pulsar wind particles. The PWN in the supernova remnant Kes 75 was recently confirmed to be the youngest PWN in the Galaxy (380-520 years, Reynolds et al 2018). This PWN provides an unique opportunity to study the early evolution of a PWN and its powering pulsar. The PWN shows distinct small-scale (<10 arcsec) features in X-rays, e.g., jets. Different PWN regions have different X-ray spectral properties. We propose ALMA observations at a similar spatial resolution as the existing X-ray data in order to study the small-scale PWN morphology in the mm, and to constrain and compare their spectral properties in X-rays and mm. | Pulsars and neutron stars | Stars and stellar evolution | 2021-03-26T18:44:45.000 |
| 2770 | 2016.1.01156.S | 14 | Communicating the energy: coupling nuclear power and molecular gas in PDS 456 | We propose to obtain the highest resolution map ever taken of the molecular gas in a hyper-luminous quasar. Our target, the nearby quasar PDS 456, has a bolometric luminosity L_bol ~ 2e47 erg/s (~ Eddington luminosity) and might be regarded as the local counterpart of the quasars shining at z ~ 2, i.e. the peak of quasar luminosity density. Our proposed ALMA observation is designed to reveal in unprecedented detail (i.e., 0.2 arsec~600 pc) the distribution of the molecular gas around a very powerful AGN and probe the relationship between nuclear and host galaxy properties at the brightest end of the luminosity function. Our target also shows the undisputedly most powerful, persistent, X-ray ultra fast (0.25c) wind discovered so far. This ALMA observation will enable a high-sensitivity search for a kpc-scale molecular outflow, studying its relation with the X-ray wind and obtaining key constraints on the acceleration and expansion mechanism for galaxy-wide outflows. Despite its unique properties, only a low-resolution and low-sensitivity CO observation with OVRO is available for PDS 456. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-06-23T16:50:49.000 |
| 2771 | 2021.1.00812.S | 166 | Studying the coronal properties of complete volume-limited sample of accreting supermassive black holes | The compact radio/mm emission observed in most Active Galactic Nuclei (AGN) is thought to be created by self-absorbed synchrotron emission from the accretion disk corona, the region which is also responsible for the X-ray emission. If this was confirmed, then the nuclear mm-emission could be an excellent tracer of AGN activity and of the AGN bolometric luminosity, being largely unaffected by obscuration. With the goal of understanding the origin of the nuclear 100 GHz emission, and its relation with the X-ray radiation, we propose to observe with ALMA, for the first time, a complete sample of nearby AGN with spatial resolutions between 4 and 45 pc. Only the exquisite resolution of ALMA can probe these scales, necessary to infer the coronal emission. A tight relation between 100 GHz and X-ray emission would provide very compelling evidence that the same emission mechanism is at work in the two bands. This would also suggest that the detection of flat nuclear mm emission is a reliable tracer of AGN activity, and would provide a new proxy of the bolometric AGN power, possibly more reliable than the X-rays. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2022-11-17T21:22:55.000 |
| 2772 | 2022.1.00326.S | 0 | HeLMS-1: An AGN-Starburst at z=1.9 | We propose to explore the morphology and kinematics of the recently identified Active Galactic Nucleus (AGN)-Starburst, HeLMS-1 at z=1.91, using ALMA in Band 9 to observe the C+ emission line. One of the strongest sources detected in the Herschel surveys, HeLMS-1 displays intense CO emission lines and dust continuum that trace structures seen in Keck and HST near-infrared images, revealing a system lensed by a group of galaxies at z=0.5. The C+ emission line, expected to be unusually strong with a flux of ~650 Jy km/s, will trace in exquisite details the reservoir of atomic gas in HeLMS-1. In addition, we will probe the dense gas of the AGN torus in the CO(16-15) emission line, together with the underlying dust continuum. The bright nature of HeLMS-1 provides a unique opportunity to reveal the C+ and dust emission at high angular resolution (0.03") and S/N across the entire lensing system. After applying a lens model, the new data will reveal, at scales of 50 pc or less in the source plane, the properties of this exceptional AGN-Starburst system at the peak of cosmic evolution, leading to a breakthrough in our understanding of this class of sources. | Starburst galaxies | Active galaxies | 2024-12-26T14:56:57.000 |
| 2773 | 2017.1.00823.S | 106 | How do GMCs start to form massive stars? An ALMA survey of young, massive star forming GMCs in the LMC | We have discovered six isolated GMCs in the Large Magellanic Cloud that do not show any sign of stellar feedback, yet contain embedded massive young stellar objects (MYSOs). These GMCs represent a unique sample of GMCs that have only recently begun to form massive stars. Our objective is to exploit ALMA's unique capabilities and the LMC's favorable orientation to determine the density substructure and the existence of dense clumps within these GMCs, and probe the initial conditions that have lead to the formation of massive stars. Given the widespread location of massive star formation in GMCs, we will use 13CO(1-0) to observe the entire GMCs instead of merely focusing on apparent hot spots of star formation. The exact location of MYSOs within GMCs will test theory, while the kinematics in the vicinity of MYSOs will probe how massive clumps form, acquire their mass, and start to form massive stars. CS(2-1) will constrain the timescale of dense gas removal around young massive stars/clusters. These observations fill a crucial gap bridging quiescent and more evolved massive star forming clouds, where the initial GMC configuration that led to the formation of massive stars is lost. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2020-01-09T00:00:00.000 |
| 2774 | 2015.1.00131.S | 10 | ALMA Identification of Submillimeter Galaxies along QSO Sightlines | Submillimeter Galaxies (SMGs) are the most likely progenitors of modern massive elliptical galaxies. Their clustering strength indicates that they inhabit massive (~1e13 Msun) halos at z ~ 2.5. Current theories predict that the majority of gas accreted by such halos should be shock-heated to temperatures ~ 10 million K. Furthermore, one predicts that this hot plasma cools too slow to sustain the extreme star formation rates of SMGs. So how do the SMGs acquire their massive reservoirs of cold gas and will their current starbursts lead to rapid quenching? To resolve these outstanding questions, we have started a program to use QSO absorption line spectroscopy to probe the circum-galactic medium of SMGs. The proposed ALMA band-7 snapshots is critical to this program. We aim at determining sub-arcsecond positions of a sample of 30 SMGs that lie within 30 arcsec of a high-redshift QSO sightline to allow future spectroscopy. This is currently impossible because the position uncertainties of the SMGs from far-IR imaging is ~5 arcsec in radius. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-05-27T21:32:12.000 |
| 2775 | 2018.1.00065.S | 53 | The H2O 448 GHz line with ALMA: the high-resolution view of the far-infrared absorption observed with Herschel | The recent first detection in space with ALMA of the ortho-H2O 448 GHz line (423-330), with energy levels at >400 K, has opened the possibility of probing and imaging the buried/warm galactic nuclei revealed by the far-IR molecular absorption detected by Herschel. The H2O 448 GHz line is pumped through absorption of far-IR (79 microns) photons, is an excellent tracer of the luminous, molecular structures in buried galaxy nuclei (Tdust>60 K, N_H>10^24 cm-2), and can be reliably modeled because it is not a maser. We propose to observe the H2O 448 GHz line in five local IR bright galaxies with evidence of inflows or outflows; all them with observations of the H2O 79 micron line responsible for the pumping of the H2O 448 GHz line. The simultaneous observation of CO 4-3 will enable the study of radiative-to-collisional excitation in galactic nuclei, an excellent diagnostic of compact vs extended IR sources, as well as the direct observation of the morphology of luminous cores and the relationship with the outflowing molecular gas. These observations will provide excellent diagnostics for future exploration of buried galactic nuclei at higher redshifts. | Galactic centres/nuclei | Active galaxies | 2021-01-10T08:22:08.000 |
| 2776 | 2018.1.01271.S | 8 | M-Type Asteroids: The Remnant Core Fragments of Differentiated Planetesimals? | Remnants of large planetesimals that were collisionally fragmented early in the Solar System's history remain today in the form of asteroids, providing a window into the early stages of planet formation. The class of high-density M-type asteroids have historically been thought to represent portions of the metallic cores of large, differentiated planetesimals. However, efforts to characterize their surface compositions have produced contradictory results; while radar albedos and thermal inertias indicate the smooth, dense surfaces expected for metallic compositions, spectroscopic features reveal the presence of silicates and even hydrated minerals. The linear polarization of thermal emission from a solid body is set by the dielectric constant and thus sensitive to the metal content of the surface, providing a new and powerful means for addressing the question of asteroid surface metallicity. We propose to map the continuum polarization of three asteroids that span purported compositions ranging from stony to metallic, in order to characterize the composition and metal content of the surfaces of M-type asteroids. | Solar system - Asteroids | Solar system | 2021-07-29T00:00:00.000 |
| 2777 | 2019.1.01247.T | 19 | A direct test of the magnetar model in the closest Superluminous Supernova | Stripped-envelope Superluminous Supernovae (SLSN-I) are stellar explosions with optical luminosities ~10-100 times that of supernovae (SNe). An extra energy source is required to account for the extreme luminosity, and recent studies favour the model where this is provided by the spin-down of a rapidly-rotating, strongly-magnetized neutron star (magnetar) formed in the SNe. Importantly, this magnetar model could account for the diverse properties across all classes of stripped-envelope SNe. Additionally, Fast Radio Bursts are attributed to pulsars/magnetars in many leading models and might be created in this way. Given the wide-ranging implications of the model, it is vital that we establish if it is valid. SN2018bsz is the closest SLSN-I discovered to date and is an ideal test case. With 4.76 hours of Band 3 and 6 observations of SN2018bsz we will either make the first direct detection of a magnetar central engine at early times, or will rule out a magnetar with the properties necessary to explain the optical emission. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2021-06-17T13:28:12.000 |
| 2778 | 2018.1.01461.S | 24 | Water deuteration and abundance on a Solar System scale in the Class I source SVS13-A | Water is a crucial molecule in Solar-like star forming regions: it is among the most abundant species in the hot corino regions (where the water-rich ices sublimate as the temperature exceeds ~100 K) and its abundance govern the chemical composition of this regions. Based on the HDO/ H2O ratio, it is argued that terrestrial water was acquired from asteroids and comets whose ices were (at least partially) formed in the protostellar phase of the Solar Nebula. However, few measurements at a Solar System scale exist so far and only for Class 0 sources, so that we have no clue how water abundance and its deuteration evolve in Solar-like protostars. We aim to measure the water abundance and its deuteration in a Class I source, in the region where asteroids and comets form (a radius of ~20au). To reach this goal, we propose to obtain <0."2 angular resolution observations towards the only Class I source where previous single-dish observations have detected the presence of warm (150 K) deuterated water on a model-estimated size of ~50 au (Codella et al. 2016a): SVS13-A. This will allow us to strongly constrain whether the water deuteration evolves from Class 0 to Class I sources. | Astrochemistry | ISM and star formation | 2021-02-07T22:58:52.000 |
| 2779 | 2018.1.01702.S | 10 | Resolving Clumps and Filaments of Cold Supernova Ejecta Dust in SNR 0540-69.3 | Supernova (SN) ejecta is a site of dust production and significant contributor to interstellar dust. The amount of dust observed in SN ejecta has been much lower than theoretical predictions until the recent detection of cold dust in the core-collapse SN remnants (CCSNRs) SN1987A, the Crab, and Cas A. 0540-69.3, the second youngest CCSNR in the LMC, contains heated SN ejecta dust in its pulsar wind nebula (PWN), as indicated by the Spitzer detection of mid-infrared emission. Using Herschel and Spitzer data, we found an additional bump in the SED consistent with dust emission at 28.6 K, indicating that 0540-69.3 is a cold dust reservoir. Herschel, however, does not have sufficient resolution to pinpoint the location of cold dust. To investigate the amount and distribution of cold ejecta dust in 0540-69.3, we request ALMA Band 8 observation to probe the dust continuum and resolve the SN ejecta clumps. We also request Band 3 and 6 observations to measure synchrotron emission in order to subtract it in the Band 8 map. We expect to resolve the clumps or filaments containing cold dust and gain insights on the dust production process in SN ejecta, especially with the presence of a PWN. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2020-12-11T10:09:45.000 |
| 2780 | 2016.1.01162.S | 27 | Evolutionary sequence for the fragmentation of high line-mass filaments | High line-mass filaments are birthplaces of high-mass stars and star clusters and thus important for Galactic scale star formation. However, description of their fragmentation and collapse is yet fundamentally lacking. One key open question is how the evolution of fragmentation proceeds. We have previously performed the most sensitive fragmentation study of a high line-mass filament to date: we characterized with ALMA the fragmentation of an evolved, actively star-forming, high-line mass filament down to 1 000 AU scales. Here we propose characterizing in a similar manner a high line-mass filament that is in an earlier stage of evolution, remarkably devoid of signs of star formation. A comparison of these two filaments enables us to determine the fragmentation pattern of high line-mass filaments as a function of star-forming status and take the first step towards building an evolutionary sequence for their fragmentation. To this goal, we wish to map the early-stage, high line-mass filament G357 in 100 GHz continuum and N2H+ line emission. These data allow us to accurately quantify the fragmentation pattern and dense gas dynamics in the filament. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-04-01T00:00:00.000 |
| 2781 | 2018.1.00028.S | 138 | Ophiuchus DIsk Survey Employing ALMA: high-resolution follow-up | Investigating planet formation in the Galaxy requires both surveys of complete disk populations and detailed studies of individual objects at very high spatial resolution. In Cycle-4, we have surveyed 147 disks in Ophiuchus at 0.2" (30 au) resolution. However, long-baseline observations show that protoplanetary disks are full of substructures (gaps and rings in particular) when observed at high enough resolution. Understanding the origin of substructures in protoplanetary disks and the implications for planet formation is one the main challenges in the field today. Here we propose to extend the Ophiuchus project by imaging 10 of the brightest disks at 0.04" (5 au) resolution in order to characterize and study the physical origin of their substructures. The sample, which includes 5 disks with large inner cavities, will result in the largest survey at 5 au resolution of disks in any given star-forming region (15 objects when combined with the objects from the Cycle-4 Large Program on disks). Therefore, this project will also serve as a demographic study of the brightest 10% of the disks in the cloud, where the most massive planets are expected to form. | Disks around low-mass stars | Disks and planet formation | 2020-10-26T17:31:26.000 |
| 2782 | 2019.1.00722.S | 1030 | Deep CO(J=1-0) mapping survey of 103 Eridanus supergroup galaxies with Morita array | We propose a 130-hr deep CO(J=1-0) mapping survey towards 103 Eridanus supergroup galaxies, aiming for measuring total amount and kpc-scale distribution of molecular gas, and understanding the dominant process for star formation quenching in the very early phase of cluster formation. Eridanus supergroup is the nearest system that will merge into a single cluster and consists of three different-type groups, one possible group, and the other loosely bounded galaxies. Sample galaxies are a combination of an HI-flux limited complete sample with an optical couterpart and the other optically identified sample. We reveal a dominant SF quenching mechanism (tidal interaction or ram-pressure stripping) in various group environments based on the CO data obtained in this proposal. Compared with our cycle-5 data of 64 Fornax cluster galaxies (same sensitivity & spatial/velocity resolutions), we investigate the relationship between cluster evolution and member galaxy evolution. This is a collaboration project with WALLABY, which is the "ASKAP HI All-Sky Survey", a precursor for future SKA HI surveys. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2021-04-27T17:22:16.000 |
| 2783 | 2024.A.00009.T | 0 | ALMA Follow-up Observations of AT2024wpp | AT2024wpp was discovered as a fast rising blue optical transient (FBOT) at a redshift of z=0.1 with luminous X-ray emission. FBOTs are a new class of transients with high luminosities, blue colors, and fast timescales that are inconsistent with traditional supernova models. Instead, models for FBOTs invoke central engines and shock interaction with dense circumstellar material. FBOTs have mainly been studied in the optical/UV regime, and the most optically luminous FBOTs (LFBOTs) show bright radio emission. LFBOTs are intrinsically rare, and only three LFBOTs have been observed at mm wavelengths to date. AT2024wpp was detecetd with ALMA in bands-3 and 5 at ~ 20 days post explosion (private communication) marking this as the fourth mm bright FBOT. Immediate follow-up observations are crucial to determine the nature of the radio emission (an extremely slow shock or a very dense environment). We propose immediate observations of AT2024wpp with ALMA in Bands 3 and 5 and request 1.1 hours of DDT time. These observations will be complemented by GMRT, MeerKAT, and ATCA observations at lower frequencies and X-ray observations at higher frequencies to build the broad band SED. | Transients | Stars and stellar evolution | 2025-05-07T11:09:52.000 |
| 2784 | 2015.1.00305.S | 2 | Quasar Feedback: Connecting the Accretion Disk Wind to the Large-Scale Molecular Outflow | In a recent Nature article, we reported the first -direct- evidence for a quasar accretion disk wind driving a massive (~800 Msun/yr) molecular outflow. The energetics of the accretion disk wind and molecular outflow are consistent with the predictions of energy-conserving flows from the latest quasar feedback models. However, this conclusion is uncertain because the mass outflow rate, momentum flux, and mechanical power of the outflowing molecular gas were inferred from our unresolved Herschel data. Here we propose to use ALMA for 8.5 hrs to pin down these parameters by detecting and resolving the associated broad wings in CO(1-0). These quantities will be compared with those of the inner quasar wind to provide the best constraints ever on the driving mechanism of quasar feedback. These observations will also be extremely useful for the interpretation of future ALMA OH observations in the distant Universe, as well as upcoming ASTRO-H X-ray data on ULIRGs and quasars. | Outflows, jets, feedback | Active galaxies | 2017-03-15T21:19:35.000 |
| 2785 | 2011.0.00750.S | 0 | The largest circumstellar disk - Birth of a high-mass star through accretion? | In 2004 we discovered a 24.000 AU symmetric dark silhouette with a stellar source in its center and a bipolar outflow perpendicular to the triangular absorption pattern in a region of high-mass star formation. CO data from PdBI indicate that the object is rotating. Optical and infrared spectroscopy of the central object yielded a wealth of emission lines with shapes typical for accreting YSOs. Since then there is the debate whether this is the first case where the formation of a high-mass star via disk accretion is directly observed in analogy to the scenario for low-mass stars. Unfortunately there are two missing links to solve this puzzle: the kinematics and the mass of the putative disk. We propose to solve the puzzle by studying some characteristic lines and the continuum of the disk. The observations will unambiguously provide the rotation curve of the disk-like silhouette and its mass. The ALMA data will answer the long-standing questions whether the disk mass is gravitationally bound to the central object and whether it is sufficiently large to create a high-mass star. This largest circumstellar disk is a must for Cycle 0 of the largest interferometer! | High-mass star formation, Disks around high-mass stars | ISM and star formation | 2015-02-12T13:54:55.000 |
| 2786 | 2023.1.00700.S | 0 | ALMA meets JWST: is there warm molecular gas near the [Fe] jet? | Sub-mm observations with ALMA have been prolific in mapping cool gas in protostellar outflows traced by low-J transitions of CO or SiO. They show a span of structures, including wide-angle winds or fast narrow jets. Their interaction with the surrounding infalling envelope can be captured through CO isotopolog observations. On the other hand, sub-millimeter observations of some Class I low-mass protostars that have slow winds do not show evidence of molecular jets. Recent JWST observations, however, have uncovered the jet component toward low-mass protostars through IR atomic/molecular lines of [Fe II] and H2. This program aims to detect the warm outflow gas that should be located between the cool CO J=2-1 gas detected with ALMA and the hot gas detected with JWST. Recent results so far indicate that the CO J=2-1 and [Fe II] jet are not co-spatial. In this proposal, we target nearby low-mass protostars that have been observed with JWST NIRSpec and MIRI, as well as CO J=2-1 with ALMA. Through these observations, we will link existing ALMA and JWST observations, and determine if the slow, cool CO emission is connected to the fast hot jet warm molecular gas. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 2787 | 2018.1.00940.S | 155 | SZ observations of 3 Cool-Core Clusters on the Sloshing Spectrum | Feedback processes have a profound influence on the physics of galaxy clusters, and are thought to be the main mechanism by which runaway cooling flows and star formation are suppressed in the cores of galaxy clusters. Feedback is also difficult to model in cosmological simulations, and is likely the main effect that can lead to a mismatch between simulations of large scale structure and observations. We propose to observe 3 cool-core clusters which are superficially similar, but contain key discrepancies in the level of gas sloshing that likely persists after past, small-scale merger events. This rich dataset will be used to probe 1) the pressure profiles in the core (thought to obey a universal form in cool-core clusters), 2) turbulence and the SZ power spectrum, 3) offsets in the SZ peak, which would challenge the X-ray and simulation-based interpretation of sloshing in clusters, and 4) bubbles from AGN feedback. These observations will also be used to probe the molecular gas in the cores of these 3 clusters, one of which (Abell 1835) already has a strong CO detection using ALMA Cycle 0 data. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2020-11-01T14:52:30.000 |
| 2788 | 2015.1.01158.S | 13 | Massive Molecular Outflows - A Window to Massive Star Formation | We propose ALMA Band 3 observations to map the inner regions of molecular outflows from 26 massive protostars. The targets are chosen from our approved SOFIA survey project. The sources can be divided into four categories: MIR sources in IRDCs, Hyper-compact, Ultra-compact and Clustered representing a range of evolutionary and environmental states. With a single pointing on each source, ALMA can complete this survey with relatively high resolution and sensitivity within 3.68 hours. Massive star formation theories based on core accretion predict collimated outflows, similar to those observed in low-mass star formation, and well-aligned outflow cavities. For each source, the requested 1.2 resolution allows us to resolve the molecular outflow inside the outflow cavity seen in IR, helping determine the outflow cavity axis position angle, inclination angle and opening angle, outflow velocity and momentum, and providing detailed information on the outflow feedback process on the core. Possible multiple outflows can also be detected and disentangled. The dependence of outflow properties on the evolutionary stage and environments of massive star formation will be studied. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2017-09-22T14:45:35.000 |
| 2789 | 2021.1.00120.S | 10 | Detecting halo heating from AGN feedback via the Sunyaev-Zeldovich Effect: confirming delayed feedback scenarios | Cosmological simulations are now invoking halo heating via quasar injection of energy around high-z galaxies to suppress cold accretion and quench star formation in massive galaxies by starvation. However, direct observational evidence of this mechanism at high-z is still missing. A long Band 4 observation of the most luminous quasar observable by ALMA (at z=1.7) has found a marginal detection of the S-Z signature tracing hot gas on scales of 300 kpc around the quasar. If confirmed this would be the first direct evidence of quasar global heating on wide halo-scales, directly confirming theoretical expectations. Detailed zoom-in cosmological simulations combined with ALMA simulations have demonstrated that Band 3 is much more effective in tracing this S-Z signature. Hence, we propose deep Band 3 observations to: 1) unambiguously confirm the detection of the S-Z signal; 2) map the S-Z radial profile, hence map the quasar heating, to be compared with predictions from cosmological simulations; 3) trace the quasar-driven molecular outflow, through CO(2-1), whose energetics can directly be compared, for the very first time, with the halo heating. | Outflows, jets, feedback | Active galaxies | 2024-01-13T15:54:56.000 |
| 2790 | 2023.1.01406.S | 0 | Dissecting the build-up of z>6 massive galaxies | QSOs at z>6 are among the brightest sources in the Universe. The mass of their black holes grows by 20x in only 100Myr via gas accretion. Their host galaxies form hundreds of solar masses per year. They are thus predicted to trace extremely rich environments, where frequent galaxy interactions and intense star formation are expected. A fundamental information to understand the growth of these systems is the interplay between the total amount of gas available to feed the hosts and the strength of the outflows (if present) that can `starve` them. We propose to exploit the unparalleled sensitivity of ALMA band 7 to study three z>6 QSOs surrounded by large Ly-Alpha nebulosities (tracing T~10^4K gas on ~30kpc scales). The observations are tailored to probe the OH 119micron line and thus to test for the presence of molecular outflows. These data will allow us to test our understanding of galaxy formation theories in dense environments, and to study the complex interplay between the molecular gas reservoir, the QSO activity, and the formation of the first massive cosmic structures. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 3000-01-01T00:00:00.000 |
| 2791 | 2015.1.01269.S | 5 | Three-dimensional mapping of the Martian water cycle | We propose to obtain three-dimensional (longitude x latitude x altitude) maps of water (H2O) and its deuterated form (HDO) across the Martian disk. Our recent water D/H infrared observations established that Mars lost an oceans worth of water (Villanueva et al. 2015), while the Curiosity rover recently discovered evidence of transient liquid water and water activity at Gale Crater (Martín-Torres et al. 2015). If Mars had a humid past, how much of these volatiles were lost to space, and how much are currently stored in the sub-surface? Are sub-surface habitable niches connecting now with the atmosphere? The answers to these fundamental questions of Mars evolution and habitability lie in isotopic ratios. The proposed ALMA observations will be coordinated with simultaneous measurements of the D and H escape rates by the space mission MAVEN and with infrared ground-based observatories (Keck and IRTF). ALMA is the best observatory to address these questions, since it offers the capability to derive vertical information, the capability to sample several isotopologues of water simultaneously, and the unique sensitivities that allow us to map the planet with unprecedented precisions. | Solar system - Planetary atmospheres | Solar system | 2017-08-19T17:47:07.000 |
| 2792 | 2016.1.00195.S | 17 | The Debris Disk Surrounding HD 107146: A Possible Super-Earth at 80 AU | We propose to observe the debris disk around the young solar analog HD 107146, which is the brightest known debris disk around a solar type star. The HD 107146 system contains an unusually broad disk that extends between 30 AU and 150 AU, and thus provides a unique opportunity to probe planet formation processes over a range of radii. Our ALMA Cycle 0 data showed an intriguing decrement in the debris emission at ~ 80 AU separation from the star. At the resolution and sensitivity of the current data, the decrement can be explained by either (1) a narrow gap attributed to dynamical clearing by a super-Earth mass planet at a radius of ~ 80 AU (Kenyon & Bromley 2015), or (2) a broad, partially cleared gap attributed to dynamical interactions with a 10-100 Earth-mass planet in an eccentric orbit at ~ 40 AU (Pearce & Wyatt 2015). We propose to observe the HD 107146 disk with two times smaller beam area and six times better sensitivity than the Cycle 0 data, which will be used to measure the width and depth of the gap at 80 AU and distinguish between possible planet formation scenarios in this system. | Debris disks | Disks and planet formation | 2018-05-09T21:46:05.000 |
| 2793 | 2021.2.00052.S | 1454 | The Home Straight - CO Redshifts of Herschel's Brightest SMGs | These observations are the final step towards finishing the redshift catalogue of 207 bright, high-redshift Herschel sources (S500 > 80 mJy, z_phot > 2). Extensive redshift searches have already robustly identified 77% of the redshifts, and using all knowledge up until now, we propose efficient ACA observations to find the redshifts for the remaining 48 galaxies using band 3, 4, and 5. Sample completion will enable unbiased spectroscopic follow-up across all sources, and provide a complete picture of cosmic star-formation seen by Herschel at the peak of cosmic evolution. These final observations of 48 galaxies require 124 hours, and fall in three separate categories; 1) we efficiently target lines to resolve redshift-degeneracies, 2) we observe fainter galaxies with deeper integrations, and 3) we cover the redshift desert for sources with deep integrations that did not reveal any line signatures. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-05-11T20:27:23.000 |
| 2794 | 2018.1.00003.S | 143 | An ALMA Survey of Lensed SMGs in the Hubble Frontier Fields (resubmission) | Gravitational lensing of massive galaxy clusters is a powerful tool to probe faint and high-redshift sources at all wavelengths. We propose an ALMA band 7 survey of an uniformly selected sample of 62 submm sources detected by JCMT/SCUBA-2 within the HST footprints of four Frontier Fields, A370, MACSJ0416, MACSJ0717, and MACSJ1149. Based on the lens models provided by the HST Frontier Fields community, our sample has a median intrinsic flux of ~ 1 mJy at 850 micron, corresponding to a SFR of ~ 100 M_sun/yr. This program will bridge the SFR gap between the dusty, submm population and the extinction-corrected UV-selected galaxies. These two populations are essentially disjoint with current samples of submm galaxies. The submm flux regime of our sample allows us to determine the critical SFR below which UV-selected galaxies alone account for all the star formation. ALMA observations will determine the optical/NIR counterparts to our submm sources. With the rich multi-wavelength data of the Frontier Fields, we will tightly constrain the properties of the ALMA-detected sources. [Resubmission of high-ranked Cycle 5 program, to be observed between May-Jul 2018] | Sub-mm Galaxies (SMG) | Galaxy evolution | 2020-09-13T15:31:57.000 |
| 2795 | 2021.1.01474.S | 5 | Magnetic Fields in a High Mass Starless Core Candidate | Core accretion models predict that high mass stars form from massive self-gravitating cores, essentially a scaled-up version of low mass star formation. However, massive starless cores are rarely observed, implying that they either have extremely short lifetimes or that core accretion is not the dominant mechanism for forming massive stars. Here we propose a detailed ALMA study of the best candidate massive prestellar core found to date: G11.92-0.61-MM2. MM2 is a strong dust continuum source, but has no indicators of star formation (no masers, cm continuum emission, or line emission in SMA and ALMA observations covering ~24GHz of bandwidth), and dust properties of MM2 indicate an incredibly compact source with M> 30 Msun within a radius of less than 1000 AU, implying densities n(H) > 10^9 cm^-3. Our goal is to determine how such a dense object could have formed. We propose (1) ALMA polarization observations to look for evidence of a dynamically important magnetic field that could support the core against gravity, or a more disordered field that may indicate the collapse of MM2 and (2) Band 8 observations to better model the temperature and density structure of MM2. | High-mass star formation | ISM and star formation | 2023-09-15T23:24:29.000 |
| 2796 | 2013.1.01178.S | 20 | Uncovering the gas reservoirs of absorption-selected galaxies | Decades of research using absorption-line techniques have characterized the physical properties of neutral gas in the Universe, and established a link between absorbers and galaxies. However, efforts to identify the absorbing galaxies themselves have been stymied by insufficient sensitivity and/or spatial resolution. We propose to use the ALMA Band-3 and Band-4 receivers to search for redshifted CO(1-0) or CO(2-1) emission from four high-metallicity, damped Lyman-alpha absorbers at z<1, the best current candidates for a search for CO emission. The proposed observations will allow us to (1) obtain the first detections of molecular emission in damped systems, (2) derive the star formation efficiency in the absorbers, by comparing the SFR with the molecular gas mass, and (3) compare the gas dynamics revealed through metal-line absorption, H-alpha nebular emission and CO molecular emission. This pilot program will establish whether deep sub-mm observations may provide mass, size, and dynamical constraints for high-z galaxies detected in absorption. This would represent the first, critical step to resolving the physical connections between HI gas in absorption and modern galaxies. | Damped Lyman Alpha (DLA) systems | Cosmology | 2016-02-26T18:20:28.000 |
| 2797 | 2019.1.01201.S | 31 | Confirming Serendipitous High-z Sources in the PHIBSS2 Fields | The Plateau de Bure High-z Blue Sequence Survey 2 (PHIBSS2) targeted typical star forming galaxies at redshifts z~0.5-2 in the 3D-HST/CANDELS fields, with the goal of understanding normal, main sequence galaxies at the peak of cosmic star formation activity. Our systematic search in the data reveal several tens of serendipitous ("secondary") detections besides the intended ("primary") targets. We have characterized the line properties of these tentative secondary sources, matching them to potential optical counterparts to constrain their redshifts. We use these sources to measure the CO luminosity function and thus the molecular gas mass density evolution out to a redshift z~4, which is key to understanding the star formation rate density evolution over cosmic time. This new approach to deriving CO luminosity functions yields results that are consistent with previous deep field work. Here we request time to follow up on six candidate CO sources in the COSMOS field to test our redshift determination, as part of the validation of our CO luminosity function methodology. | Galaxy structure & evolution | Galaxy evolution | 2021-04-14T14:18:57.000 |
| 2798 | 2023.1.01099.S | 0 | Towards resolving orbiting binary SMBH, plus shadows, jets, and accretion flows of single SMBH: ACA fluxes | The photon ring around the supermassive black hole (SMBH) in M87 has been imaged with the Event Horizon Telescope (EHT), and results on SgrA* are in the pipeline. With ALMA passive-phasing, the EHT can now detect sources of a few 10s of mJy. Additional SMBH photon rings are likely resolvable by the EHT, but these SMBHs are faint at centimeter radio (weak/no jets), and their 230 GHz flux (accretion inflow) is unknown. We propose to measure the 230 GHz flux of 68 SMBHs with photon ring > 8 microarcsec (piggy-backing 611 more SMBHs with photon ring > 2 microarcsec) and 124 SMBH binary (SMBHB) candidates. i.e., a total of 803 'large ring' SMBHs and SMBHB candidates. Those with nuclear flux > 10mJy will be followed up with the 12m array, VLBA, and eventually the best with EHT. Our longer term goals are to identify all SMBHs in which the EHT can resolve the photon ring and jet base, and to drive the technical requirements of the next-generation-EHT. Even only a few new EHT-feasible 'large ring' galaxies will allow the transformational results in M87 and SgrA* to be leveraged to a larger number of galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-04-05T11:47:49.000 |
| 2799 | 2016.1.00077.S | 18 | High angular-resolution image of supernova 1987A - mixing and formation of HCO+ | From the ALMA cycle-2 spectral line scan program, we discovered HCO+ from the ejecta of supernova 1987A. The estimated HCO+ mass was about 12 orders of magnitude greater than the mass predicted by chemical models. In order to determine where and how HCO+ was formed, we propose to obtain high-angular resolution HCO+ image. The classical image of the stellar interior of the progenitor star is often illustrated as onion-style layers of different nuclear burning zones. If a supernova sustained this geometrical structure after the explosion, HCO+ cannot be formed --- hydrogen atoms are from the hydrogen envelope, while carbon and oxygen atoms are from the helium envelope and carbon+oxygen nuclear burning zones. The likely way to form HCO+ is that mixing of elements from different nuclear burning zones took place immediately after the supernova explosion. If that is the case, we expect that HCO+ would be more extended than SiO, and that would coincide or be slightly more extended than CO and He I, and coincident with or slightly more compact than Halpha. The distribution of HCO+ can therefore give important insight in the hydrodynamics and mixing processes in the explosion itself. | Supernovae (SN) ejecta | Stars and stellar evolution | 2020-12-17T18:39:34.000 |
| 2800 | 2013.1.00826.S | 3 | Forensic pathology of the extreme ULIRG F00183-7111 | A radio-loud AGN has just switched on in the centre of ULIRG F00183-7111 and radio jets are boring their way through the galaxy, heating and disrupting the cold molecular gas and eventually quenching star formation. In ALMA Cycle 0 we successfully observed CO(1-0) in this source. Here we propose to use the high resolution of Cycle 2 ALMA to image the CO(3-2) around the super-massive black hole (SMBH) to see how the gas is interacting with the jets and the SMBH, testing the standard model of AGN feedback. The ALMA resolution requested here, corresponding to 750pc at the redshift (0.329) of 00183, will enable us to observe heating and deposition of kinetic energy into the gas close to the jets. Finding evidence for this is the primary goal of this proposal, and will be a fundamental test of AGN feedback models. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2016-12-15T19:21:44.000 |
| 2801 | 2018.1.01276.S | 49 | Tracing the heritage of cometary water through the HDO/H2O ratio | Materials throughout the Solar System exhibit differing degrees of deuterium enrichment, the measurement of which provides clues to their origin and thermal history. We propose to measure the D/H ratio in water in comet 21P/Giacobini-Zinner, to test whether the cometary water originated in the interstellar medium or has been significantly processed. Simultaneous emission line observations of other species will be used to measure the temperature and will allow the retrieval of accurate production rates using a non-LTE excitation code. The proposed measurements will advance our knowledge of how and where comets formed, and help elucidate the role of comets in delivering water and organics to primitive planetary surfaces. | Solar system - Comets | Solar system | 3000-01-01T00:00:00.000 |
| 2802 | 2015.1.00981.S | 29 | A survey of the [NII]205 um / [CII]ratio at z=1 | We propose to use ALMA band 9 to observe the [NII]205 um transition in 5 galaxies at z=1.2 from which we have detected emission in the [CII]158 um line. The [CII] transition is emitted by molecular gas ionized and heated by stellar UV radiation, and in the ALMA era promises to be a crucial workhorse in high redshift surveys. The [NII]205 um line is a sensitive tracer of ionized gas, and complements the [CII] line as a star formation diagnostic. We will use the [NII] line to measure the fraction of the ISM in these galaxies that has been ionized by stellar radiation, and use this to determine the intensity of the starburst. We will also use the [NII] line, compared with the continuum emission, to trace the hardness of the UV field, thereby determining the spectral type of the most massive stars or inferring the presence of an AGN. Finally, we will use the [NII]/[CII] ratio to determine how much of the measured [CII] arises from ionized gas rather than PDRs. These observations will be an essential reference for future ALMA high-z [CII] studies. This project is a resubmission of a highly ranked cycle 1 project (carried over to cycle 2) with updated source list. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2018-06-02T17:47:21.000 |
| 2803 | 2012.1.00158.S | 6 | Quantifying gas inside dust cavities in transitional disks: mass, distribution and composition | Transitional disks with large inner dust cavities are thought to be the best laboratories for studying disk evolution during the planet-forming stage. Little is known about the gas inside dust cavities, yet this gas significantly affects planet formation through gas-grain dynamics and planetary migration whereas its chemistry controls the composition of gas-giant atmospheres. We propose here pioneering ALMA Band 7 observations of 13CO, C18O and CN 3-2 lines and the millimeter continuum to provide deep searches for molecular gas inside the dust cavities. The three proposed sources are part of only a handful of transitional disks with known CO IR emission and large enough dust cavities to be studied in Cycle 1. They span a range of spectral types and other disk parameters, allowing similarities and differences among the small sample to be studied. The huge leap in sensitivity provided by ALMA, in combination with new thermo-chemical models to interpret the data, allows a large range of gas masses inside the hole to be tested, down to about an Earth mass. This, in turn, allows the origin of the cavity in this disk to be determined: substellar or (multi-)planetary mass companions versus grain growth or photoevaporation. The CN/CO ratio provides initial insight into the chemical composition of the gas and its variations within and outside the cavity. | Disks around low-mass stars | Disks and planet formation | 2015-09-05T13:43:48.000 |
| 2804 | 2021.1.01567.V | 0 | Jet Meets Black Hole in M87: Breaking New Ground with GMVA+ALMA | The black hole shadow and its polarized structure in the nearby radio galaxy M87 have recently been imaged for the first time with the EHT at 1.3 mm. This opens up a new era for direct imaging studies of black holes and their immediate vicinity. However, it is still unclear how the powerful M87 jet is launched and accelerated to relativistic speeds. The most important information for understanding these processes can only be extracted by resolving the jet base. This is now achievable with 3.5 mm observations with GMVA+ALMA. Here we propose follow-up observations of M87 for two VLBI epochs over a time interval of approx. 5 days, aiming to: 1) further improve imaging fidelity and resolution (via improved S/N, uv-coverage), 2) confirm the hollow jet base detected in the 2018 GMVA+ALMA observations, 3) study the BH-jet connection, and 4) search for possible variability, 5) obtain a polarimetric image of higher angular resolution at 3.5 mm to determine the B-field and its topology, 6) determine the spectral index and RM in combination with the EHT imaging at 1.3 mm, which constrains the energy budget and particle composition. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 3000-01-01T00:00:00.000 |
| 2805 | 2017.1.00077.S | 61 | Dissecting to decipher: an ALMA study of the high-mass star formation processes in RCW 120 | Two scenarii are proposed for the formation of massive stars: strong accretion fueled by a high degree of turbulence or competitive accretion. Each scenario can be uniquely identified during the early phases of high mass star formation by looking at the fragmentation and dynamical processes at high resolution in the millimeter wave range. Recent ALMA and PdBI results in high mass star forming regions show either a high degree of fragmentation (Rathborne et al. 2015, Beuther et al. 2013) or filaments' collision converging on a high mass core (Fukui et al. 2015). We suggest that the mechanism controlling the high mass star formation might depend on the immediate environment of the high mass core. We propose to test this hypothesis by observing with ALMA Band~3, 6, and 7 the continuum and line emissions towards two massive young sources located at the edges of RCW 120, in the highest column density part of its photodissociation region. The sources are in different evolutionary stages and live in different environments. With ALMA data we will characterize their true spatial structure and derive their velocity structure to identify the mechanisms that drive their formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-04-02T18:15:49.000 |
| 2806 | 2015.1.00271.S | 3 | The molecular outflow from Arp220 | We will image the molecular outflow from the archetypical ULIRG Arp220 in the OH+ 909GHz line redshifted into band 10. This line, which is only a factor 2 less bright than mid-J CO lines, exhibits a spectacular P-Cygni profile in the Herschel spectrum, indicating that all of the OH+ signal participates in the molecular outflow (and not just small fraction as with other tracers). We will locate the origin of the outflow, map its velocity field, and determine the outflow velocity. By comparing to other gas tracers we will determine mass outflow rate and momentum end energy flux in the outflow. We will use the OH+ abundance with respect to other species to determine its location and origin. This presents a unique opportunity to compare the OH+ outflow, which is a readily accessible outflow tracer at high z, to other molecular tracers in a local galaxy. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-04-26T18:29:56.000 |
| 2807 | 2022.1.00319.S | 22 | Fully Constraining the Average Molecular ISM Conditions at the Peak Epoch of Star Formation | Star-forming galaxies at the peak epoch for star formation, z~2, have been observed with large sub-/millimetre facilities for over a decade, yet the conditions within their molecular ISM remains ill-constrained. Reliable modeling tools have recently been developed, but what is missing is a representative sample of galaxies with the full set of dust, CO and atomic carbon observations. Current samples suffer from poorly constrained lensing models and/or miss the anchor point of the CO excitation ladder, CO(1-0). We therefore propose to observe the only homogeneously-selected sample of unlensed galaxies with existing high S/N measurements of 3 Herschel/SPIRE bands, CO(1-0) and CO(3-2) (from the VLA and NOEMA). We propose to target their CO(4-3), [CI] 1-0, CO(7-6), [CI] 2-1, 1.1- and 2-mm dust-continuum emission, with only two frequency tunings each. By efficiently completing the CO and [CI] excitation ladders and sampling the full dust spectral energy distribution, we will accurately constrain the dust and gas temperatures, gas densities and interstellar radiation field strengths. We will also cross-correlate all molecular gas tracers at z~2, by modeling these self-consistently. | Galaxy structure & evolution | Galaxy evolution | 2024-01-13T20:55:45.000 |
| 2808 | 2019.1.00462.S | 8 | How do high-mass protostars assemble their mass in the Central Molecular Zone? | The Central Molecular Zone (CMZ) is a unique Galactic high-mass star forming environment, with physical conditions that are extreme compared to the Galactic disk, yet it is near enough that we can observe it on the scales of individual protostars. It is becoming clear that accretion disks play an important role in the formation of high-mass stars in the Galactic disk, but it is not known if this holds true in the CMZ, or whether the physical conditions may suppress the formation of accretion disks. Our previous ALMA observations have identified a high-mass protostar in the CMZ that is uniquely suited to investigating this question. The source is massive, young, and resides in a relatively unclustered region. It has a class II methanol maser, a bi-polar outflow, and shows signatures of rotation, providing tentative evidence for the presence of a massive disk feeding a massive protostar. We propose to observe this source down to scales of 250 AU to determine whether there is an accretion disk present, or if the formation of high-mass stars is fundamentally different in this extreme Galactic environment. | High-mass star formation | ISM and star formation | 2022-12-12T12:09:51.000 |
| 2809 | 2017.1.01324.S | 526 | Resolving Submm Galaxy Nests in z~4 Protoclusters | Galaxy evolution in high-density environments is an important open issues. Cluster galaxies, especially brightest cluster galaxies, are expected to experience intense and short-duration star-formation activity. These galaxies would be identified as sub-mm bright galaxies (SMGs) in high-redshift protoclusters. Thus, SMGs are key targets to reveal the environmental effects on galaxy evolution. The Hyper SuprimeCam survey discovered significantly overdense regions of z~4 galaxies from ~120deg^2 area. We have conducted a systematic submm follow-up imaging by the JCMT/SCUBA-2 though its spatial resolution is not good. From the proposed observation, we will localize or resolve the 67 SMGs identified by the SCUBA-2/850um in six protocluster candidates by the capability of higher-resolution imaging of the ALMA in order to investigate 1) spatial distribution and true sub-mm flux of SMGs, 2) optical counterparts, and 3) the diversity of protoclusters. Based on these results, we will be able to approach the relation between SMGs and environments, which enables us to discuss the history of cluster formation by comparing with protoclusters at lower redshift and local galaxy clusters. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2019-03-18T06:55:19.000 |
| 2810 | 2022.1.01634.S | 37 | H2 spin chemistry constraints from redshifted NH3 ortho and para lines | The ortho-to-para ratio (OPR) of H2 is a key parameter of the spin state and chemistry of interstellar H2, which impacts interstellar chemistry in general and even gas thermodynamic properties. It is difficult to measure directly the OPR of H2 in standard conditions of the interstellar medium, but it can be indirectly retrieved using observations of OPR of other hydrides like NH3. The high frequencies of the ground state transitions of ortho- and para-NH3 makes it difficult for ground based observations of Galactic sources, but they are readily accessible with ALMA for redshifted sources, like the extragalactic absorber at z=0.89 toward the lensed quasar PKS 1830-211. Here we propose to use this unique opportunity to further investigate and measure the NH3 OPR with an accuracy of 10% or better, rivaling all previous measurements, thanks to ALMA. Our proposed NH3 OPR observations promise unequaled constraints on the chemical and physical conditions and thermal history of its environment and, ultimately, will provide new insights on both the nuclear-spin astrochemistry and properties of the interstellar medium. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-10-18T18:37:05.000 |
| 2811 | 2017.1.01079.S | 0 | Unveiling the disk around the massive protostar powering the magnetized HH 80-81 jet | HH80-81 represents a unique case where the basic ingredients showing that high-mass protostars form through an accreting disk with a magnetic field are present: A magnetized highly collimated jet; a disk perpendicular to the jet; possible rotating motions of the molecular gas around the massive protostar. Now, ALMA full polarization observations at 45mas has well resolved the disk for the first time and we have detected a polarization pattern that is suggestive of scattering in an optically thick disk. There is not any other known massive YSO showing together all these signatures. The ALMA data has been combined with the use of irradiated accretion disk models that allow to unveil the disk and stellar mass, the accretion rate, the disk kinematical behavior and the relevance of the magnetic fields. However, there are strong degeneracies that can only be unveiled with observations at longer wavelengths. Thus, the goal of this proposal is to characterize the accretion disk around the powering source of the HH80-81 radio jet,to to reveal the dust properties of the disk and tracing the elusive kinematics within the disk. | Disks around high-mass stars | Disks and planet formation | 2018-12-28T18:28:48.000 |
| 2812 | 2016.1.00724.S | 92 | Turbulence in a Sample of Protoplanetary Disks | Turbulence is a central component of planet formation theory, yet observational constraints on its magnitude and spatial distribution have so far been scarce. In a pilot study of HD 163296 ALMA Science Verification CO(3-2) emission we found that the high spatial resolution data were able to limit turbulence to less than 3% of the local sound speed. This upper limit is almost an order of magnitude lower than predicted from theory, but it is not clear if this result is unique to this source. Here we propose to extend the sample to include new CO observations of three additional sources. When combined with our constraints in HD 163296, and archival ALMA observations of TW Hya, this sample will cover a wide range of ionizing flux, a crucial parameter for setting the size of the MRI-active region. Additional observations of 13CO and C18O will be used to distinguish between MRI and gravito-turbulence based on the distinct predictions for the vertical turbulent velocity gradient from these two theories of the angular momentum transport in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2017-11-18T08:38:58.000 |
| 2813 | 2017.1.01031.S | 77 | A complete study of FU/EX Or objects | We propose to observe all FUor and EXor objects within 1 kpc that have not been observed by ALMA so far. By observing in Band 6 at 0.1'' resolution (40 au at 400 pc) we aim at completing our previous Early Science survey for FUors and EXors. Our previous ALMA results indicate the disks are smaller but more massive than their T Tauri counterparts, and the FU Ori disks are systematically more massive than EXOr. However these results are limited to a small (objects) sample from a single region (Orion). We propose double the sample and completing the observation of all episodic accretion systems observable by ALMA to produce the most compelling statistical millimeter study of outbursting systems to date. | Disks around low-mass stars | Disks and planet formation | 2019-10-10T20:23:45.000 |
| 2814 | 2016.1.00375.S | 26 | High velocity inflow onto the central engine of NGC 1052 | To understand mass accretion mechanism onto central engines of active galactic nuclei, we propose Band 3 and 4 observation of SiO and HCN absorption features toward the radio galaxy NGC 1052. Our goal is to confirm the high-velocity inflow found in our Cycle-2 observations in Band 6 and 7. We found a ring-like rotating circumnuclear disk (CND) in CO emission and rich absorption lines of CO, HCN, HCO+, CS, SO, CN, and SiO towards the nucleus. Appearance of vib-excited HCN and HCO+ indicates that molecular gas in CND is heated by warm dust radiation. We also detected extremely redshifted SiO absorption features (500 - 1700 km/s w.r.t. the systemic velocity). We consider that HCN is evaporated from icy mantle of dust grains and SiO is sputtered from silicate core of dust, which is losing angular momentum via radiation drag. To verify this radiation-drag dust inflow model, it is crucial to confirm the SiO and HCN absorption features in other transitions to avoid line misidentifications and to estimate physical conditions based on multiple excitation states and isotopologues. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-09-05T17:00:17.000 |
| 2815 | 2021.1.00407.S | 134 | Lifting the shroud on two IRAC-dark dusty star-forming galaxies | We propose ALMA 12m array linescans for two IRAC-dark (m_4.5 > 24 ABmag) dusty star-forming galaxies (DSFGs) discovered with ALMA behind two lensing clusters. Both objects are detected at high S/N in ALMA, yet lack clear counterparts even in medium-deep HST and IRAC imaging, implying that they either lie at very high redshifts (z>6-10) or are obscured by unusually high A_v (>5-10) at z~3-5. We aim to detect at least 2 bright CO transitions in order to establish firm redshifts and characterize their molecular gas (mass, excitation curves, kinematics, t_depl) and dust properties (mass, temperature). Precise physical constraints from ALMA, which are unattainable by UV/opt/NIR/MIR methods, will advance our understanding of star formation for these intriguing objects and place them into cosmological context amongst star-forming galaxies more generally. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-06-30T19:49:34.000 |
| 2816 | 2023.1.00161.S | 0 | A Comprehensive [CII] Survey of Herschel-Selected Starbursts at z=1-2 | Based on recent surveys of the most luminous massive starburst galaxies found in >1000deg2 observed with Herschel, a comprehensive sample of >300 sources with secure, CO/CI-based spectroscopic redshifts now exists. Here we propose to detect [CII] 158um emission from the star-forming ISM in all 37 galaxies in this sample at z=1-2 that are observable with the ACA, complementing 102 galaxies at z=3-6 already observed or scheduled in cycle 7-9, providing the (by almost an order of magnitude) largest massive starburst [CII] sample. In combination with the rich suite of diagnostics already available, this study will provide critical insight into the physical properties of the ISM that set the conditions for star formation for a statistically significant sample. Based on >10 systems in the sample for which <=1kpc resolution [CII] imaging with the ALMA 12m array is available, the ACA data will also provide a critical test for the potential presence of low surface brightness emission on >10kpc scales due to an enriched cold circum-galactic medium missed by high-resolution studies, as has been suggested to exist in star-forming galaxies in the early universe by some recent theoretical work. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2025-10-08T13:19:25.000 |
| 2817 | 2016.1.01250.S | 18 | Toward the Baryon Census of a z=0.31 Galaxy Group and Diffuse Gas Structure | Galaxy halos appear to be missing approximately 60% of their baryons, most probably hiding in the circumgalactic medium (CGM), a diffuse component within the dark matter halo that extends far from the inner regions of the galaxies. A powerful tool to study the CGM gas is offered by absorption lines in the spectra of background quasars. Here, we propose to target a unique field surrounding a log N(HI)=21.71+/-0.07 absorber at z=0.3127. Ground-based VLT/MUSE 3D spectroscopy indicates that the neutral gas is related with a group of galaxies, three of which are new discoveries. Even more spectacular is the presence of two distinct regions of diffuse gas showing the prominent emission lines such as [O II], [O III], [H-beta] and [H-alpha]. This structure is therefore ideal to relate the neutral atomic gas, molecular gas and the stars in the same galaxy group. Here, we request ALMA band 3 observations to observe the CO(1-0) molecular gas. The goal of this pilot project is to provide the first census of baryon in a complex structure of galaxies. In the future, such studies can be extended to a larger sample of MUSE-detected galaxy groups at the position of the quasar absorbers. | Starburst galaxies, Damped Lyman Alpha (DLA) systems | Active galaxies | 2017-12-30T20:43:18.000 |
| 2818 | 2021.1.01375.S | 154 | SYMPHANY- SYnergy of Molecular PHase And Neutral hYdrogen in galaxies in Abell 2626 | We propose the SYMPHANY survey to image the morphologies and kinematics of the molecular gas disks in 44 galaxies in Abell 2626 at z=0.0545 with the CO(2-1) line at a resolution of 1.4 kpc by 20 km/s and a surface density sensitivity of 5 Msun/pc^2. We will investigate the efficiency of gas removal mechanisms that act on a galaxys multi-phase ISM and that result in the quenching of its star formation (SF) activity as it falls into a dense cluster environment. By merits of their spatial and velocity resolutions, the ALMA data cubes are crucially complementary to existing MeerKAT HI and proposed INT H-alpha imaging data, along with MeerKAT 1.4 GHz, AstroSAT/GALEX UV and WISE 22 micron images to characterize the SF activity. The sample size allows to study trends in the distribution and kinematics of the multi-phase ISM with galaxy mass, SF activity, HI deficiency, cluster centric distance, local environment etc. Comparing the multi-phase ISM and SF activity of galaxies in A2626 with that of galaxies in the equally massive Virgo and more relaxed Fornax clusters will shed light on the influence of a clusters mass and dynamical state on the evolution of their constituent galaxies. | Spiral galaxies, Surveys of galaxies | Local Universe | 3000-01-01T00:00:00.000 |
| 2819 | 2013.1.00957.S | 14 | On the origin of the astonishing maser emission in G9.62+0.19 complex | We propose to carry out higher spatial resolution observations of SiO, H30$\alpha$ and other dense molecular tracers (e.g. CH$_{3}$OH lines) as well as continuum at 230 GHz towards the G9.62+0.19 complex. The observations are to determine the origin of the active maser emissions in this region. We expect to resolve the continuum sources in this region. We will for the first time tell whether the periodic maser emission in G9.62+0.19 E is caused by a colliding-wind binary system or not. The SiO observations will reveal the outflow jets in the hot core G9.62+0.19 F. The H30$\alpha$ line can help determine whether G9.62+0.19 B is expanding and interacting with the dust cores. Thus we can tell whether the shock front traced by maser emission is due to the ionization front emerging from G9.62+0.19 B or due to the outflow jets generated from G9.62+0.19 F. These studies will greatly improve our understanding of the formation and feedback of high-mass stars in clustered environment. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2016-10-06T19:16:14.000 |
| 2820 | 2018.1.01510.S | 162 | Hot or Cold? Characterizing the temperature structure of young disks in Perseus | In contrast to protoplanetary disks, the physical and chemical conditions of young disks still embedded in their envelopes remain largely uncharacterized. An important unknown is the temperature structure since this strongly affects the disk's chemical composition, and therefore the composition of planet-forming material. The more evolved protoplanetary disks have been shown to contain large cold regions where CO is frozen out onto the dust grains, but embedded disks are predicted to be too warm for CO freeze-out. Our recent analysis of the Class 0 disk L1527 suggests that this disk is indeed warm enough to prevent CO freeze-out (van 't Hoff et al. 2018). We propose to investigate the temperature structure of six disk candidates in Perseus using observations of DCO+, N2D+ and DCN. Determining whether these young disks are warm or cold will show whether the onset of planet formation happens in a cold environment with CO frozen out, as observed for protoplanetary disks, or in a warm CO gas-rich environment. | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-09-09T15:23:34.000 |
| 2821 | 2015.1.00330.S | 54 | Gas Dynamics of Dusty Star-Forming Galaxies in the First 1.5 Billion Years | Dusty star-forming galaxies (DSFGs) at high redshift are thought to be dominantly highly dissipative mergers of gas-rich galaxies that represent extreme, short-lived starbursts. This picture is supported by studies of gas dynamics, but unfortunately, the resolution of past studies remained limited to 3-4 kpc even for the best handful of cases (with only a single exception), which is barely adequate to resolve the galaxies. Through a novel selection technique based on Herschel/SPIRE colors, we have identified a new sample of DSFGs at z=4.16-6.34. Using the new long baselines of ALMA, we propose to study the [CII] gas dynamics, OH and dust in 4 representative z=4.2-5.2 starbursts in our sample down to 500pc resolution. Based on dynamical models, we will investigate the occurence rate of major mergers vs. disks, measure dynamical masses, and constrain the physical properties of individual gas clumps down to physical scales not previously accessible outside the local universe. We will also search for faint, "CO-dark", perhaps low-metallicity companion galaxies within 100-150kpc of our massive, dusty starbursts. This comprehensive investigation will remain unrivaled for years to come. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-01-14T07:44:41.000 |
| 2822 | 2017.1.01677.S | 51 | Unveiling the gas distribution in 5 gas rich main-sequence star-forming galaxies at 3<z<3.5 | We aim at high resolution imaging in band 4 (0.2, corresponding to 1.5 kpc) to map the CO(5-4) and dust continuum distribution in a benchmark sample of 5 massive (10.5 | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2019-02-22T22:44:49.000 |
| 2823 | 2015.1.00023.S | 40 | Understanding the Disk Wind from HD 163296 | With the ALMA Science Verification (SV) data of HD 163296, we made the first detection of a molecular disk wind; the type of wind that is extremely useful in extracting angular momentum from a star forming disk. Disk winds had been predicted in the 1980's, but proved illusive until the sensitivities possible with ALMA were achieved. Now we are proposing to make the FIRST full map of this newly detected type of wind. In so doing, we will quantify its full extent, its kinematics, how it interacts with its environment, and, most importantly, constrain its launching mechanism. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-05-07T21:59:04.000 |
| 2824 | 2017.1.00388.S | 131 | Unveiling the Nature of the Hot Inner Disks around Accretion Outburst YSOs | Young stellar objects (YSOs) which are undergoing accretion outbursts may be surrounded by high-density hot inner disks (HID) on a few AU scales, which are required to feed protostellar accretion at a high rate. Only very high angular resolution observations at frequencies lower than 200 GHz can probe the dust emission of HID without being significantly confused by disk structures exterior to the HID. Physical properties of the rather obscured HID can be diagnosed with SED analysis at millimeter bands, analogous to the widely applied fitting of the infrared SED to diagnose the more extended dust structures around YSOs. However, presently only ALMA long baseline observations at Band 3 and Band 4 towards nearer than 500 pc sources can provide the adequate S/N within a realistic observing time. We propose to perform a comprehensive survey towards 16 selected nearby accretion outburst YSOs. Our main goals are to characterize the mass, size, and temperature of the HIDs. The proposed observations will be of paramount importance for the understanding of the accretion outburts of YSOs, and can provide important constraints on the innermost protoplanetary disk structures in general. | Disks around low-mass stars | Disks and planet formation | 2018-12-21T06:31:46.000 |
| 2825 | 2013.1.00834.S | 10 | High Velocity Masers in the Galactic Center: A New Probe of General Relativity | We propose to conduct a search for high-velocity circumstellar SiO masers close to the Galactic central black hole (Sgr A*). Position and velocity tracking of maser-emitting stars within 0.1 pc of Sgr A* will provide multiple direct probes of the metric (stellar motion plus light propagation) and will enable numerous tests of general relativity not possible with binary pulsars. If SiO maser-emitting stars are identified close to Sgr A*, then the exceptional spatial and spectral resolution of the complete ALMA can test the equivalence principle, the "no-hair" theorem of black holes, and frame-dragging. While previous surveys for low-velocity masers have been done, the proposed survey will be 10 times more sensitive and will have 100 times the bandwidth to detect high velocity stars deep in the gravitational potential of the central black hole. Our maser survey requires a single pointing and tuning and only 38 minutes of on-source integration (1.21 hours total). The proposed observations will resolve stellar positions down to 0.01 pc from the central black hole and identify high-velocity stars at distances as small as 0.001 pc. | Galactic centres/nuclei | Active galaxies | 2016-07-31T08:16:47.000 |
| 2826 | 2019.1.00534.S | 90 | Revealing hot cores in the Small Magellanic Cloud | The Magellanic Clouds are excellent targets to study the chemical properties of star-forming complexes at low metallicity. Sub-pc resolution observations, and therefore the detection of 0.1 pc size hot cores are became possible with ALMA at the distance of the Magellanic Clouds. Previous ALMA studies identified three hot cores and complex organic molecules in the Large Magellanic Cloud. In the lower metallicity Small Megallanic Cloud, a handful of CO and CI observations are available, but we still lack the detailed observations of other molecules at sub-pc resolution. Only one embeddd YSO was studied so far with ALMA, no hot core was detected around it, but its chemical properties was revealed. Here we propose ALMA Band 7 observations towards 6 high-mass YSOs in the SMC with a spatial resolution of 0.1 pc. We target SO2, HCO+, H2CO, CH3OH, HNCO, H2CS, NO, etc. lines to identify hot cores and we will compare the fractional abundances of the detected molecules to that of the hot cores in the Galaxy and in the Large Magellanic Clouds. The results will help us to better understand the chemial processes in the low metallicity environment, which characterised the early Universe. | Astrochemistry, Magellanic Clouds | ISM and star formation | 2021-02-04T21:17:18.000 |
| 2827 | 2013.1.00171.S | 19 | Cold gas in AGNs hosts: walking along the 'main-sequence' of star-forming galaxies. | Probing the properties of the molecular gas reservoir is a key ingredient of galaxy evolutionary studies: it is out of this gas that ultimately stars are formed. An open question is what is the role of black holes in the evolution of the gas content of their hosts. Previous CO studies of AGNs have been focused on bright quasars, whose hosts are well above the 'main-sequence'. But most of z>1 AGNs and star-forming galaxies are actually located in this 'main-sequence'. The main goal of this proposal is to use ALMA to address the scientic question: does the presence of an active SMBH affect the cold gas content of 'main-sequence' galaxies at z~1.5?. We propose to measure the CO(2-1) in a representative sample of 'main-sequence' z~1.5 AGNs. The measure will allow us to: a) Compare the star-formation efficiency of 'main-sequence' galaxies hosting AGNs with that of inactive galaxies and verify if AGN feedback is modifying the star-formation process in its host (e.g. positive feedback). b) Compare the gas fraction of these active galaxies with that measured for inactive galaxies and test if the molecular gas content in SMBHs hosts has changed due to AGN feedback. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2016-08-01T10:16:49.000 |
| 2828 | 2018.1.01518.S | 4 | Heating in small-scale explosive events in the chromosphere | Active regions are known to host small-scale heating events observed as transient, bright blobs that light-up in optical and UV wavelengths. Magnetic reconnection has been usually invoked to explain their visibility and associated jets and plasmoids. However, tracking their physical properties has been hampered by the few available chromospheric diagnostics such as Mg II h and k formed in non-LTE, and of difficult interpretation. We propose a new look into these phenomena with ALMA whose LTE diagnostic power should provide stronger constraints on their typical temperature enhancements and formation heights which have been matter of debate. Based on simulations of the solar atmosphere using a new non-LTE inversion code, we have found that ALMA Band 6 increases the accuracy of inversions of IRIS observations. Such combination can be used to infer temperatures in the chromosphere as function of height, meaning that we will be able not only to observe the spatial/temporal changes in the mm-brightness of impulsive heating events, but also to closely follow the evolution of their thermal structure, while constraining magnetic reconnection models. | The Sun | Sun | 2020-08-06T20:40:42.000 |
| 2829 | 2015.1.00623.S | 10 | AGN feedback and jet triggered star formation in Abell 1795 | Extended cool gas filaments are common in brightest cluster galaxies located in cool core galaxy clusters but, at 46 kpc in length (38 arcsec), A1795 hosts the most spectacular example. Emitting soft X-rays, Halpha and molecular lines, this filament likely traces a wake of gas cooling from the cluster atmosphere onto the central galaxy. This stream of cooling gas may eventually supply fuel to the the central powerful FR I radio source 4C 26.42, which has inflated two large radio bubbles that have displaced and compressed the surrounding medium. Knots of young star clusters clearly trace the edges of the radio lobes where the jets have collided with dense clouds and triggered their collapse into intense starbursts. We propose ALMA observations to study the spatial and velocity distribution of molecular gas in the core of A1795 to reveal the steady condensation of gas cooling from the cluster and examine the nature of jet-cloud interactions. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2017-08-08T18:15:59.000 |
| 2830 | 2015.1.00038.S | 13 | On the dominant stellar feedback mechanism in massive Super Star Clusters | The Antennae Galaxies hosts one of the most massive super star cluster known, SSC B1. From VLT/SINFONI observations, we find that this cluster is associated with bright compact ionized and molecular gas emission. It is an ideal source to investigate the impact of massive clusters on their surrounding gas. We propose to observe the CO(3-2) line emission at 10 pc resolution. This resolution is needed to probe molecular clouds from very near the cluster itself up to the frontier of its local environment. By determining the distribution of the molecular gas and measuring the velocity dispersion, we aim to constrain feedback mechanisms and molecular cloud properties in regions where SSC form. | Merging and interacting galaxies | Galaxy evolution | 2018-01-25T09:49:44.000 |
| 2831 | 2022.1.00126.S | 7 | Studying the Origin and Composition of Large-Scale Arc-like Structures Around Young Stars | ALMA observations have revealed a handful of Class 0-II objects that show evidence for interactions either with their surroundings or other objects in the form of large-scale, arc-like structures that extend for 100s, even 1,000s of AU. Though few examples currently exist, such features deserve careful attention because the sudden, large influx of mass that would provide may trigger the many features we see in disks, including rings, spiral arms, misalignments, and accretion outbursts. The detection of these arcs has been limited to molecular line emission and scattered light, with the exception of [MGM2012] 512 (M512). M512 is thus far the only object to show such a large-scale, arc-like feature in both molecular lines and the millimeter dust continuum. This makes M512 an object uniquely capable of shedding light on the structure, dynamics, composition, and origin of these increasingly common (and likely important) arc-like objects. Here we propose a detailed study of M512 which will allow us to characterize the dust content in the arc, as well as pinpoint its origin and assess the degree of grain growth in the envelope and surrounding environment of M512. | Low-mass star formation | ISM and star formation | 2024-01-27T19:47:37.000 |
| 2832 | 2018.1.01406.S | 10 | Is the unique ultracool object closest to Earth radio-loud? | WISE J085510.83-071442.5 (W0855) is an unique object the coldest known brown dwarf (BD) with a temperature of only ~250 K, located just 2.2 pc away. It is extremely faint, even at mid-infrared (MIR) where its spectral energy distribution peaks, making it difficult to investigate if it has companions. However, some cool brown dwarfs (BDs) can have magnetic fields in excess of 1kG and they can emit related radio emission. The angular resolution in the radio regimen can be much higher than in the optical/MIR. Here we propose a pilot project to take advantage of this effect. Out first goal is to investigate the radio properties of W0855 with combined Band 3 and 7 observations. If W0855 is detectable within a reasonable time, we plan to embark (via future proposal) on a radio-astrometric monitoring campaign to search for companions/planets with much higher accuracy than the best current effort with Spitzer. Should we fail to detect radio emission from W0855, our finding will set an upper limit on the magnetic field of this extremely faint object that is beyond the reach of the modern/near-future high-res spectrographs. | Brown dwarfs | Stars and stellar evolution | 2020-12-19T09:02:41.000 |
| 2833 | 2023.1.00073.S | 0 | Unveiling the Nature of the GC Magnetic Field and the Unique Non-thermal Filaments Using ALMA | The Galactic Center (GC) is an extreme region of the galaxy that we can observe to probe the properties of more distant galactic nuclear regions. A population of unique structures is present within the GC: the non-thermal filaments (NTFs). The NTFs pervade the GC and have magnetic field distributions that trace their total intensity distributions. This property implies the existence of a large-scale vertical magnetic field in the GC. Recent arcsecond-scale observations of a prominent NTF known as the Radio Arc, have revealed a magnetic field which alternates from being parallel to rotated with respect to the orientation of the Radio Arc. This magnetic field distribution could be evidence that the magnetic field traced by the NTFs is less uniform than previously thought. Furthermore, the Radio Arc has a flatter spectral index at centimeter wavelengths than other NTFs, which could indicate that it is a young structure. High resolution ALMA observations of the Radio Arc at 100 GHz will allow us to investigate these unique Radio Arc properties. Such investigation could reveal how the Radio Arc was formed an enhance our understanding of the GC magnetic field. | Galactic centres/nuclei | Active galaxies | 2025-11-06T19:09:11.000 |
| 2834 | 2013.1.00374.S | 8 | Formation of Wide-Separation, Low-Mass Companions: the GQ Lup System | We propose to image circumstellar material in the GQ Lup system, a very young Sun-like star with a well characterized substellar (possibly planetary) mass companion in a 100 AU orbit. Such low-mass, wide-separation companions present serious challenges to standard models of both planet and binary star formation. ALMA provides the high sensitivity and resolution to detect and isolate circumstellar emission from various components in nearby systems like this and to provide new constraints on formation mechanisms. In particular, millimeter imaging can constrain (1) the presence of a remnant outer disk that could point to "planet-like" formation of the companion within a large disk around the primary, (2) the presence and mass of a "circumplanetary" disk around the companion that would be difficult to reconcile with scenarios where the companion was formed closer in and scattered or migrated outward, and (3) sculpting of the disk around the primary, such as a cavity, that could point to an additional close in object involved in a dynamical interaction that. Both detections and non-detections of these circumstellar features will address the viability of proposed formation mechanisms. | Disks around low-mass stars | Disks and planet formation | 2016-12-16T00:00:00.000 |
| 2835 | 2015.1.00086.S | 39 | Understanding Nuclear Streaming: stellar, atomic, and molecular gas kinematics in the inner 100pc: Continuation | In this continuation project, we propose CO kinematic observtions of six nearby galaxies, chosen to show streaming inflows/outflows and/or bright (IR) molecular disks in our 0.5arcsec resolution optical and IR Integral Field observations. The 0.5arcsec images of the proposed galaxies (plus the four galaxies already observed by us and a handful of others in the ALMA archive) will allow us to: a) map the CO distribution, morphology and kinematics on kpc to 50pc scales, for comparison with stellar features (e.g. bars and disks) and kinematics b) search for signatures of molecular gas inflows and outflows and compare the corresponding molecular and ionized gas mass rates using models of circular rotation and stellar kinematics as references. c) compare mass inflow/outflow rates with nuclear star formation rates and black hole accretion rates and thus constrain the inflow timescales. | Active Galactic Nuclei (AGN)/Quasars (QSO), Spiral galaxies | Active galaxies | 2017-08-15T18:37:39.000 |
| 2836 | 2016.1.01453.S | 18 | Shock chemistry of a unique Herbig-Haro jet | We have identified a new Herbig-Haro (HH) jet, HH 1165, in the sigma Orionis cluster. At an Lbol ~0.1 Lsun, HH 1165 is the lowest luminosity HH jet identified to date. Deep optical images show a spectacular extended jet and multiple shock structure. The jet position velocity diagrams show clear asymmetric jet morphology, where the peak in emission is blue-shifted. Molecular gas line observations obtained with the SMA show blue-shifted emission in the CO (2-1) line, indicating a molecular outflow. A serendipitous discovery in our SMA data is significantly blue-shifted detection in the shock diagnostic of SiO (5-4) line. This is the first detection of a shock-associated line in a very low-luminosity jet. However, the quality of SMA spectra is poor. We propose to conduct a high-sensitivity sub-millimeter spectral line survey of the HH 1165 shocked regions with the ALMA interferometer. The high capabilities of ALMA will allow a detailed study of the shock chemistry in multiple lines, and at various knots along the jet. The proposed observations will be the first step in understanding the chemical composition in shocked regions towards very low-luminosity HH sources. | Outflows, jets and ionized winds | ISM and star formation | 2018-06-10T00:00:00.000 |
| 2837 | 2018.1.01359.S | 93 | Resolving the [CII] distribution and kinematics of "normal" galaxies at the end of cosmic reionization | Substantial advances have been made in the recent years to understand the nature of the bulk population of galaxies at the end of the cosmic reionization era, at z=5-8, based on detection of the [CII] line emission. We are now in an excellent position to give one step further by resolving this emission, and understand the governing physical processes in the formation of these primeval galaxies. Here, we propose to perform high resolution [CII] line observations (0.5-1.5 kpc scale) of a sample of 7 galaxies at z=5.5-7.0, which represent the bulk of population of normal galaxies at this epoch. We aim to spatially resolve the [CII] line emission in all our targets (0.1-0.3") and perform dynamical analysis in 3 of them. We have two primary goals, (i) to measure the morphology and distribution of the cool gas, compared to the star-forming and stellar components (i.e. mergers, disks, clumpy) and (ii) to perform three dimensional dynamical modelling of the velocity field. In turn, this will lead to estimation of key parameters, including gas and dynamical masses, depletion timescales, and gas fractions and their relation to UV radiation fields. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-01-02T19:16:49.000 |
| 2838 | 2011.0.00002.E | 0 | Pluto Band 7 TDM data in support of NASA JPL New Horizons Mission: Pluto band 7: continuum | ALMA engineering data release. | 2018-07-10T12:50:52.000 | ||
| 2839 | 2022.1.00875.L | 2510 | The ALMA Disk-Exoplanet C/Onnection | Protoplanetary disks set the initial composition of future planetary systems. Comparing the chemistry of disks to the compositions of exoplanet atmospheres - a major priority for current space missions - informs our understanding of the planet-formation process. ALMA's unmatched capabilities have enabled huge advances in our view of disk chemistry, but our most studied systems are not representative of the exoplanet population. We propose to survey C2H, N2H+, and CO, which as a complete set allows us to derive gas-phase C/O and metallicity (C/H, O/H) via comparison with state-of-the-art astrochemical models. We will observe 80 disks across four star forming regions, sampling a range of stellar masses, disk sizes, and environments. We will examine the disk gas compositions to search for commonalities/differences between regions and across the entire sample. Our spectral setup additionally provides key data on sulfur chemistry, the formation of organics, and D/H for the most comprehensive sample of disks to date. This survey will revolutionize our understanding of the chemical diversity occurring in more "typical" disks and how it imprints on the diversity of exoplanet populations. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2024-03-16T20:55:23.000 |
| 2840 | 2016.1.01505.S | 47 | Resolving the launching of the HH 30 CO outflow | The accretion phase of star formation is correlated with the ejection of material through jets and outflows. Although widespread throughout star formation the link between accretion and ejection remains poorly understood. Two main questions remains: where does these jets/outflows come from and what is the mass/angular momentum they extract from the disk-star system. Our previous observations of the prototypical HH 30 edge-on disk source with ALMA have revealed in the spectacular way the close connexion of the CO outflow with the underlying accretion disk but we still lack angular resolution to: (i) infer the launching radius of the flow, that is of first importance in discriminating between the different models (ii) accurately compute the mass and angular momentum extracted by the jflow and (iii) properly derive the inclination of the disk (critical parameter to constrain). To answer these questions we propose to map the HH 30 flow in band 7 in continuum and CO line emissions at 0.1" angular resolution. We additionally request band 4 continuum observations to check for the puzzling non detection of the central cavity in band 6, expected in this binary system. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-01-26T18:29:32.000 |
| 2841 | 2015.1.00870.S | 131 | Evolution of the interstellar gas fraction over cosmic time | Two fundamental questions regarding the formation and evolution of galaxies are how they acquire their gas content and how this is turned into stars. Observations at restframe optical wavelengths suggest that at z>4 the gas accretion rate exceeds the star formation rate and the baryonic content is dominated by the interstellar gas. We currently have very limited observational data on the evolution of the gas and the star formation history of galaxies at z>2. It is therefore of vital importance to establish the gas fraction in galaxies as a function of redshift. This is now possible with ALMA and we propose to observe a sample of galaxies at z~2, 3, 4 and 5, using dust continuum as a proxy for the interstellar gas. The sample selection is based on the multi-epoch abundance method which allows us to pick galaxies at different redshifts which are progenitors of a galaxy of fixed stellar mass at z=0. This type of selection is crucial for studying real evolutionary effects across cosmic time. The stellar mass of all galaxies in our sample is high enough to ensure that metallicity will not affect the dust-to-ISM conversion. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2018-06-29T00:00:00.000 |
| 2842 | 2019.1.01144.S | 108 | Toward a complete investigation on the Nature of the Inner Disks around Accretion Outburst YSOs | Young stellar objects (YSOs) which are undergoing accretion outbursts may be surrounded by high-density hot inner disks (HID) on a few AU scales, which are required to feed protostellar accretion at a high rate. Only very high angular resolution observations at frequencies lower than 200 GHz can probe the dust emission of HID without being significantly confused by disk structures exterior to the HID. Physical properties of the rather obscured HID can be diagnosed with SED analysis at millimeter bands. We request to observe 9 sources in Cycle-7. Our main goals are to characterize the mass, size, and temperature of the HIDs. The proposed observations will lead to a high angular resolution ALMA database for the previously known and observable accretion outburst YSOs. Our aim is to test whether or not piling up mass at the dense HIDs is definitely universal when triggering outbursts, which will also shed light on addressing the missing, planet-forming mass from the previous surveys towards Class II YSOs. | Disks around low-mass stars | Disks and planet formation | 2022-09-14T15:23:20.000 |
| 2843 | 2013.1.00244.S | 7 | Water released in a protostellar accretion burst | Low-mass protostars have been suggested to show highly variable accretion rates throughout their evolution. Such changes in accretion, and related heating of their ambient envelopes, may trigger significant chemical spatial and source-to-source variations. In ALMA Cycle 0 observations of the deeply embedded protostar IRAS 15398-3359, we detected a depression in the emission of H13CO+ in the inner 150-200 AU of the central protostellar core. This likely reflects that HCO+ is destroyed by reactions with extended water vapor present in parts of the core where the temperature is as low as 30 K, well below the freeze-out value. A possible explanation for this extended destruction by water is that the water vapor has been released due to an accretion burst during the last 100-1000 years, which increased the luminosity of IRAS 15398-3359 by a factor 100 above its current luminosity and thus caused the water ice mantles on large scales to evaporate. We here propose to image the emission from two water isotopologues in band-8 to confirm this picture and to reveal the gas dynamics affected by this recent burst and its relation to the newly-formed disk. | Low-mass star formation, Astrochemistry | ISM and star formation | 2016-07-17T00:00:00.000 |
| 2844 | 2019.1.00146.S | 0 | A turning point in our understanding of filamentary high-mass star formation: the dynamical role of the B-field | The role of the magnetic field (B-field) remains ambiguous in high-mass star formation. To address this, we adopt the promising approach the comparative analysis between the B-field and velocity-field in both orientation and amplitude. This approach can be put into practice effectively in the era of ALMA, thanks to its unparalleled sensitivity, and the capability of the correlator to simultaneously measure both dust polarization and spectral lines. We propose to observe nine dense clumps in G351, a high-mass star forming filament, at a resolution of 3.6" in Band 3 with full polarization in the continuum and the spectral line N2H+ (1-0). Taking advantage of the different evolutionary stages of the clumps, the continuum polarization and velocity measurements will permit us to examine in detail the relation between the B-field and velocity field. Specifically we will probe variations in B-field versus velocity orientation and amplitude as a function of evolutionary stage on scales of ~0.1-0.02 pc. These observations will place direct observational constraints on the role of the B-field and its interaction with gravity and turbulence in high-mass star formation. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-10-14T22:26:19.000 |
| 2845 | 2015.1.00486.S | 1 | On the Gas-to-Gust Mass ratio in T Tauri Disks | Theories of planet formation are currently limited by our poor understanding of the structure of the disks in which planets form. Observations of gas and dust are the only way to learn about the disc physical structure at the time of planet formation. With this proposal we want to perform an exploratory program to estimate a fundamental physical parameter in disks: the gas-to-dust mass ratio. To do this we ask for sensitive (3 mJy/beam), high angular resolution (0.15'') observations of 2 well-studied sources in 3 CO isotopologues and 1 continuum band. The proposed observations will allow us to image, for the first time, the inner regions of the disks in these sources. The scope of this program is to test our methodology to measure the gas-to-dust mass ratio in disks which will serve as a basis for a large program with ALMA. | Disks around low-mass stars | Disks and planet formation | 2018-02-01T20:24:09.000 |
| 2846 | 2016.1.00161.S | 81 | Planetary Nebulae genesis: emerging HII regions around post-AGB stars. | Based on the exciting results from our pilot search for radio recombination lines (RRLs) in a small sample of pPNe/yPNe, we propose to map with ALMA (0.03-0.09"-resolution) the emerging ionized cores of three representative objects: CRL618, M2-9, and MWC922. RRLs at mm-wavelengths are unique probes of the dense inner regions of pPNe/yPNe, where the yet unknown agents for PN-shaping operate, and which are usually heavily obscured at shorter wavelengths by optically thick circumstellar dust shells. In most pPNe/yPNe, mm-RRLs have intensities and line-to-continuum flux ratios larger than cm-RRLs and, thus, are more easily detectable. Most importantly, cm-RRLs are tracers of the relatively tenuous environments (<1e3cm-3) of evolved and well developed PNe but NOT of the dense (>1e5cm-3) inner winds of pPNe/yPNe. The proposed observations and subsequent data modelling with our non-LTE 3D radiative transfer code MORELI will certainly produce significant new insights into the physical conditions, structure, and dynamics of the, up to date inscrutable, inner regions of pPNe/yPNe where the physical mechanisms responsible for the onset of bipolarity and polar acceleration in PNe are active. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2019-02-22T03:43:05.000 |
| 2847 | 2019.1.01030.S | 234 | Deep CO (3-2) and continuum survey of Rosette Nebula globulettes | Our previous optical, NIR, (sub)mm single dish and ALMA observations and modelling of very tiny molecular clouds, globulettes, that reside in H II regions surrounding young stellar clusters, open a number of questions regarding their nature and fate. How long can they survive in the hot nebular gas and UV radiation field? Are they gravitationally unstable to form free-floating planetary mass objects and low-mass brown dwarfs to be ejected into interstellar space? We propose a CO (3-2) and 340GHz continuum survey of 27 Rosette Nebula globulettes of different sizes and shapes. The point source three sigma continuum detection limit will 5 be Jupiter masses. The observations will show what percentage of the globulettes have dense cores, are there associated continuum point sources or dust continuum emission, allow to estimate the Rosette globulette mass and velocity dispersion distribution, are the smallest globulettes in the last stage before evaporating in the hard UV radiation field and in particular, are the globulettes a viable source of brown dwarfs and free floating planets. The project will thus have an impact on the wider field of planet and low-mass star formation. | Inter-Stellar Medium (ISM)/Molecular clouds, HII regions | ISM and star formation | 2021-04-04T01:08:26.000 |
| 2848 | 2015.1.00040.S | 22 | Using [CI]to determine the distribution and heating mechanism of H2 in a z=4.8 star-forming disk | In Cycle 0 we identified a large, rotating [CII] disk in a strongly star-forming galaxy at z=4.8, ALESS73.1. Its [CII] line emission extends well beyond the host galaxy, tracing unknown distributions of ionized (HII), atomic (HI) and molecular (H2) gas (De Breuck et al. 2014). Here we propose resolution-matched, [CI] (1-0) & (2-1) imaging, whose low critical densities and umbiquity in H2 gas clouds (without significant contamination from HII or HI gas, and not subject to cosmic ray destruction) promise a powerful new luminous tracer of H2 gas in galaxies. Our goals include: a) determine the full extent, gas mass and enclosed dynamical mass of H2 disks, b) uncover potentially serious biases of the bright [CII] line in tracing H2 gas in galaxies, and c) determine whether FUV photons from the starburst can maintain the average thermal state of the dense H2 gas. The latter strongly impacts on the initial conditions of star formation and whether they can be reset in such disks. Thanks to its fortuitous redshift (allowing both [CI] and [CII] lines to be observed), and its unlensed isolated nature, ALESS73.1 is an excellent testbed for spatially resolved ISM studies. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-01-17T20:12:01.000 |
| 2849 | 2023.1.01370.S | 0 | Filament formation and triggered star formation by cloud collision in NGC 1333 | We propose to observe the NGC 1333 molecular cloud with a mosaic mapping and study how cloud-cloud collisions (CCCs) form filaments and induce star formation. CCCs are a promising mechanism for generating dense gas that can collapse into massive stars or clusters. Filamentary structures are also observed in interstellar clouds with various masses and may be related to gas collisions. We will observe filaments with different column densities and star formation activity in the NGC 1333 cloud in CO isotopes and some dense gas tracers at 0.01 pc resolution, which is sufficient to resolve the filament substructures. We will also use shock tracers such as SiO and CH3OH to confirm the presence of collision and compare the observed filament substructure with the oblique shock model predicted by MHD simulations. We will classify the filaments according to their line masses and divide them into evolutionary stages based on their star formation activity. We will investigate how CCCs enhance the mass accretion onto the filaments and increase their line masses above the critical value for gravitational instability. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-03-19T15:35:23.000 |
| 2850 | 2022.1.00611.S | 0 | Unveiling NGC 7479 torus innermost structure with ALMA | NGC 7479 is a nearby (z=0.0079) Compton-thick AGN. The simultaneous multi-epoch analysis of its X-ray spectra made it possible to obtain tight constraints on the torus general parameters such as the covering factor, the inclination angle and the average column density. The spectral analysis suggests a physical separation between the material resposible for reflection (reflector) and the one resposible for absorption (absorber); in particular, the X-ray spectral fitting requires the presence of an extra reflector, decoupled from the line-of-sight component. Our goal is to disentangle, for the first time, the absorber and the reflector of NGC 7479 torus, in order to get precise information on its torus properties, sizes and composition. The comparison between ALMA data and previous X-ray analysis will then allow us to get even better constrains on the localization of the obsuring material. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-11-28T00:06:00.000 |
| 2851 | 2017.1.00828.S | 45 | The reddened pale dot. Is a disk the responsible of the red colour of HD206893B? | The system around the star HD 206893 is composed of a brown dwarf low-mass companion and an outer debris disk. The brown dwarf HD 206893B is the reddest object among the companions found to date with high-contrast imagers. Both synthetic and empirical models with extremely dusty atmospheres cannot match the NIR excess of its spectrum. We propose to look for the presence of a disk around this low-mass companion. The SED of a system composed of the BD and a disk around it can match the NIR observations. ALMA is the only instrument with a sensitivity and a resolution that can make this detection possible. We will constrain the nature of this disk around the low-mass companion, and distinguish it between a long-lasting primordial accreting or a debris disk. In addition, we will study the interaction between the BD companion and the outer debris disk to recover the dynamical history of the system. Asymmetries in the inner edge of the outer disk could have been sculpted by the brown dwarf itself or by other smaller objects outside the orbit of the brown dwarf. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2019-06-03T10:19:42.000 |
| 2852 | 2016.1.00505.S | 3 | Probing the earliest stage of protostellar evolution using the CH3OH lines | We propose to observe the first core candidates B1-bN and B1-bS, and a class 0 protostar B1-c using the ground-state CH3OH 5_k--4_k lines at 241.8 GHz. The goal of this project is to search for the compact CH3OH emission from the first core itself. The chemical model of the first core predicts that CH3OH lines can be the suitable tracer for the first core, because its gas-phase abundance jumps up by three orders of magnitude in the first core. In order to detect the compact emission from the first core, we would like to achieve the angular resolution of 0.2", which is comparable to the size of the first core. The ALMA band-6 receiver allow us to observe the CH3OH lines in the torsionally excited state at 241 GHz at the same time. The CH3OH lines at two different states would be helpful in studying the physical and chemical conditions of the first core candidates. In addition, we plan to observe the H2CO 3_1,2--2_1,1, HDO 3_1,2--2_2,1 and C17O 2--1 lines in the image sideband. These lines would be helpful in understanding the physical and chemical conditions of the first cores, | Low-mass star formation | ISM and star formation | 2018-03-21T17:08:36.000 |
| 2853 | 2017.A.00006.S | 0 | First detection of a circumplanetary disk within the gap of a protoplanetary disk | Transition disks (TDs) mark a key evolutionary stage of the planet formation process and their study is of prime interest to understand the physical and chemical conditions under which planet formation takes place. Only few detections of planets within these disks exist, and most of them are under debate. We recently detected a substellar companion within the gap of the PDS 70 TD in near-infrared scattered light using VLT/SPHERE. Its photometry reveals that the source is most probably a massive planet surrounded by a circumplanetary disk (CPD). In this proposal we aim using ALMA, operating in band 7 at a resolution of 0.03-0.06", to detect the CPD in the sub-millimeter. In addition to a direct detection in the dust continuum, we will use the molecular line emission (CO) as indirect tracers of the companion and its disk. Further, the analysis of the TD will complete our study of the system and the processes of planet-disk interaction. This system is a unique case where these processes can be studied at a first-hand example. The proposed ALMA observations would correspond to the first direct detection of such a CPD in the gap of a protoplanetary disk. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2018-07-13T05:54:19.000 |
| 2854 | 2019.2.00230.S | 10 | ALMA Survey of Coma Cluster Jellyfish Galaxies | We propose to map CO(2-1) emission in a sample of jellyfish galaxies with long ionized and star-forming tails in the Coma cluster. This will provide a first ever statistically important survey of the molecular component of ram pressure stripped (RPS) tails. The sample of 18 galaxies is rich in its variety of different stages of stripping, stellar masses, projected locations in the cluster and geometries. Coma cluster is an ideal laboratory for systematic multi-wavelength studies of RPS - it has the richest optical data among nearby clusters, some of the tails have UV, soft X-rays, CO emission detected, we also have HST observations, JVLA data, Herschel FIR data, and we have MUSE data for a subsample of the galaxies. The proposed survey will increase the number of detected molecular RPS tails up to 3x, and the number of mapped tails up to 10x. We will learn about the evolution of the stripped ISM, about mixing with the surrounding ICM from comparison with other gas phases, the formation and evolution of the molecular component, as well as distinguish between other factors that affect RPS. We will also study the (low) efficiency of star formation in the harsh tail environments. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2022-10-05T17:11:15.000 |
| 2855 | 2017.1.01209.S | 48 | The state of interstellar medium in galaxies in a giant Lyman-alpha blob | Lyman-alpha blob (LABs) are extended gaseous nebulae, preferentially found in overdense environments in the eaerly Universe. Recently our ALMA observations of 6 LABs at z = 3.1 have shown that all 6 LABs contain one or more dusty star-forming galaxies. The results definitively show that dust-obscured star-formation is frequently associated with LABs and both phenomena are somehow physically linked. In characterizing the physical and chemical conditions of the interstellar medium (ISM), FIR fine-structure lines are expected to be keys. We propose deep [CII]158um and [NII]205um mapping of a giant LAB, SSA22-LAB1 in band 8 and band 7. The data will allow us for the first time to use robust ISM diagnostics for intense star-forming galaxies in LAB1, which are the most plausible power sources of the extended Ly emission. The survey will also detect the [CII] line from vairous galaxy populations, which will be critical observational tests of LAB models. | Lyman Alpha Emitters/Blobs (LAE/LAB), Starburst galaxies | Galaxy evolution | 2019-06-11T01:32:13.000 |
| 2856 | 2013.1.00708.S | 116 | Probing Dust and Gas Evolution in Disks: The pivotal Chamaeleon II association | Dust in Protoplanetary disks dissipates with typical timescales of ~3 Myr. By 10Myr, very few disks are detected and little primordial material is left. The formation of gaseous planets must be complete by then. However, this is based almost entirely on measurements of the continuum, of dust, and it assumes that the gas dissipates on the same timescale. Very little information is available regarding the gas dispersal timescale. The Cha II association has an estimated age of about 3-4Myr. The disk detection rate in Cha II, as seen by continuum, is down to ~50% for KM stars making Cha II a perfect place to study disk evolution at the critical time when they evolve rapidly. For comparison the same fraction is ~80% in the 1-2Myr Taurus and Rho Oph. We propose to survey all known K&M stars with disks of the Chamaeleon II association to measure the band 6 continuum and resolve the disk sizes. We also propose to observe three CO isotopologues to search for the presence cold gas. The sample is carefully selected in stellar mass and will be readily comparable, including gas for the first time,with younger associations with minimum biases. | Disks around low-mass stars | Disks and planet formation | 2016-11-29T04:41:13.000 |
| 2857 | 2018.1.00828.S | 93 | Feeding the Beasts: Investigating the Merger-Induced Growth of Star-bursting BCGs from 0.7<z<1.7 | We have discovered a new, and unexpected, formation mechanism for the most massive galaxies in the local universe: Brightest Cluster Galaxies or BCGs. Our recent studies have shown that substantial in-situ star formation is occurring in high-z BCGs. We have posited that the driver of this ULIRG-level star formation above z~1 is the merger of a gas-rich galaxy with the BCG, in contrast to rare cooling flow fed systems at z < 1. Here, we propose for 7 hours of Band-6 high-resolution continuum imaging for a study of 13 BCGs within massive SpARCS clusters, spanning the redshift range of 0.7 | Starburst galaxies, Galaxy Clusters | Active galaxies | 2019-11-26T14:19:35.000 |
| 2858 | 2016.1.01012.S | 35 | Gas Contents of the Host Galaxies of z>3 X-ray Selected AGN in COSMOS | Measuring the gas and dust content in galaxies is critical for our understanding of galaxy evolution, as this is the fuel for both star formation and supermassive black hole (SMBH) growth. Until recently, these measurements have been done using the CO lines. However, it is far more efficient to derive the total mass in the interstellar medium (ISM) using a single measurement of the far-IR continuum flux in the optically thin Rayleigh-Jeans regime. This, combined with the unsurpassed sensitivity of ALMA and the so-called ``negative k-correction'', allows for the first time to measure ISM masses for sizable samples of galaxies up to high redshifts. Here, we propose to obtain ALMA band 6 measurements of the dust continuum fluxes for a sample of 27 host galaxies of X-ray detected, obscured Active Galactic Nuclei (AGN) at z>3 in the COSMOS field. With these data we will derive ISM masses as a function of stellar mass and other physical properties, and test if AGN host galaxies at high redshifts are richer in gas in comparison to normal galaxies and hence shed light on the mechanism triggering SMBH growth episodes and its evolution. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-05-25T20:28:38.000 |
| 2859 | 2019.1.01463.S | 18 | Gas accretion in the last thousand AU around high-mass protostars: filamentary streamers or disks? | One of the key questions concerning high-mass star formation is gas accretion, from clumps or filaments of pc scales to dense cores of 0.1 pc scales, and eventually down to protostellar objects of <1000 AU scales. Whether gas in the last 1000 AU is accreted onto protostars through filamentary streamers or Keplerian disks is still unclear. In our previous survey of 8 massive filamentary clouds, we have found signatures of accretion along radial and major axes of filaments, indicating dense cores are accreting gas from the enviromnent to form high-mass protostars. To trace how this gas flow further falls to the accretion disk scale, we propose to follow up with higher resolution towards three massive dense cores at different evolutionary stages. We aim to resolve the substructures in inner regions of the cores in continuum and CH3CN lines at a linear resolution of ~100 AU, and investigate whether the envelope gas is accretion onto protostellar objects through complex filamentary streamers or ordered Keplerian disks. | High-mass star formation | ISM and star formation | 2022-08-20T17:53:14.000 |
| 2860 | 2015.1.00102.S | 146 | Warm and Dense Molecular Gas in Local Merging ULIRGs | Hierarchical galaxy formation scenario predicts that galaxy-galaxy interaction and merger are the fundamental process that govern the evolution of galaxies in the universe, changing the galaxy morphology and triggering intense starbursts and/or AGN activity. Recent high resolution simulations have shown that tidal interaction is responsible for forming massive clumps of dense gas surrounded by diffuse gas clouds and triggering star formation across the galaxy disks. An observational test of gas response requires mapping both the diffuse and dense gas tracers in merging U/LIRGs at high spatial resolution. Here we propose a systematic CO(3-2), HCN(4-3), HCO+(4-3) survey of 6 of the brightest merging ULIRGs in the local universe at 0.3 arcsec (200 pc) resolution of ALMA Band 7. The primary aim of this study is to map the distribution and kinematics of warm/dense molecular gas and the dense gas mass fraction and interpret their relation to star formation and AGN activities in the context of the merger-induced response of the ISM in the progenitor disks. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2017-11-08T08:45:39.000 |
| 2861 | 2016.1.00007.S | 17 | Full synthesis imaging of the AFGL 3068 spiral pattern - deriving binary properties | We have confirmed the presence of a very-well defined spiral-shell pattern in the circumstellar envelope of the extreme carbon star AFGL 3068 in 12CO, 13CO, and HC3N. These data, from our partially executed Cycle 2 program, while preliminary, provide tantalizing hints that the orbit is non-circular and that the dust and gas are strongly coupled. We request Cycle 4 observations to complete our program in order to robustly determine the binary stellar and orbital parameters for AFGL 3068. The spiral-shell patterns trace the history of binary motion, and therefore have potential in resolving the puzzling coexistence of long-period ring patterns and bipolar structures found in many planetary nebulae. A detailed study on the archetypal spiral pattern of AFGL 3068 is prerequisite for broader application of binary theory to the late evolution of giant stars and planetary nebulae. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-06-24T00:00:00.000 |
| 2862 | 2013.1.00941.S | 1 | Shedding Light on Distant Starburst Galaxies Hosting Dust-Obscured gamma-ray Bursts | Studies of distant starburst galaxies hosting GRBs offer unique insights into extreme star-forming regions during early epochs. In particular, 25-40% of all GRBs show a suppressed optical to x-ray ratio in the afterglow. A likely explanation is that they originate in dusty galaxies, which are commonly missed in optical surveys. We have carried out a successful program in ALMA Cycle 0 to observe the galaxy hosting the dark GRB 080607 at z = 3.036. We obtained a marginal detection of its 345 GHZ continuum, placing it at the faintest end of the dusty galaxy population. The result indicates that the large extinction (Av ~ 3) in the afterglow is confined along a dusty sight line, contrary to the expectation of the host galaxy itself being dusty. Here we propose deep imaging of the 345 GHz continuum from a larger sample of six galaxies hosting dust-obscured GRBs at z > 1.5. All six galaxies have spectroscopic redshifts to confirm that the suppressed optical fluxes are indeed due to extinction, rather than IGM absorption. The proposed imaging will allow us to characterize the global dust content of the host galaxies and put them in a broader context of the dusty galaxy population. | Starburst galaxies, Gamma Ray Bursts (GRB) | Active galaxies | 2016-09-07T10:54:14.000 |
| 2863 | 2015.1.01404.S | 11 | Probing the velocity structure of the NGC 6334 filament | Herschel observations of nearby clouds support a paradigm for low-mass star formation in which filaments play a central role. First, the dissipation of kinetic energy in large-scale MHD flows generates ~ 0.1 pc-wide filaments in the ISM. Second, the densest filaments fragment into prestellar cores above the line mass threshold for gravitational instability. Two major open problems are 1) to understand how dense star-forming (SF) filaments can maintain a roughly constant inner width ~ 0.1 pc while evolving, and 2) to determine if the same picture applies to more distant clouds forming high-mass stars. Single-dish mm line observations and modelling of nearby filaments suggest that the solution to the first problem is ``accretion-driven internal turbulence'', which generates a complex braid-like density/velocity structure in the filaments. Here, we propose to test this scenario for a more massive filament in the high-mass SF cloud NGC6334, by mosaicing the filament in the N2H+(1-0) line and 3.2 mm continuum. The results will be compared with MHD simulations of accreting/collapsing filaments and are expected to give key insight into the dynamical evolution of massive SF filaments. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2017-09-02T10:56:59.000 |
| 2864 | 2017.1.01658.S | 166 | Complete Census of Bright Lensed Submillimeter Galaxies Discovered by the Herschel Lensing Survey | To discover exceptionally bright cluster-lensed submillimeter galaxies (SMGs) like the Cosmic Eyelash, our team has been conducting a large Herschel survey of gravitationally lensed galaxies in the fields of massive galaxy clusters: The Herschel Lensing Survey (HLS) (PI: Egami). The HLS has obtained deep PACS (100/160 um) and SPIRE (250/350/500 um) images of 54 massive galaxy clusters as well as shallower (but nearly confusion-limited) SPIRE images of 527 clusters with a total observing time of ~420 hours. Now completed, HLS has identified a number of exceptionally bright Herschel sources that are likely lensed SMGs at z>1. Here, we propose to complete our ALMA Band-6 high-resolution (beam=0.2") imaging of the brightest 23 HLS sources by observing the eight sources that still remain in the queue. ALMA high-resolution images are essential for, (1) identifying the counterparts and lensing geometry, (2) examining the relation between the dust continuum sources and the stellar continuum sources detected at shorter wavelengths, and (3) probing the physical properties of individual star-forming regions at the sub-kpc scale through the reconstruction of the source-plane image. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-01-31T20:34:58.000 |
| 2865 | 2012.1.00978.S | 8 | Timing the birth of the red sequence | One of the most remarkable recent discoveries in galaxy evolution studies is that up to half of the most massive galaxies at z=2 are old quiescent systems with extremely compact structure. It is a major puzzle how these systems have assembled their large stellar mass contents at such early cosmic times. Starbursting, and dust-enshrouded high reshift (z>4) (submillimeter) galaxies (SMGs) are thought to be their most likely progenitors. We have only recently been able to assemble the first, unique sample of 7 spectroscopically confirmed z>4 SMGs in the COSMOS field. Using the improved ALMA capabilities in Cycle 1, allowing us to reach angular resolutions matched to that of HST, we propose for ALMA band 7 continuum observations at 0.2" resolution towards our z>4 SMGs to infer the sizes of their star-formation regions, and directly link them to the sizes of the compact stellar remnants at z~2. At the same time these observations will also allow us to constrain dynamical masses, based on transitions of atomic lines falling in our observing windows. Both accurate size and (dynamical) mass determinations are critical to draw unambiguous conclusions for an evolutionary link between these two very special galaxy populations (z>4 SMGs and z~2 massive quiescent systems) whose number densities do match in our target field (COSMOS). | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2016-07-31T10:13:29.000 |
| 2866 | 2021.1.01727.S | 10 | Unveiling the AGN impact on the ISM in local Seyfert2 galaxies by tracing the dense gas at sub-kpc scale | We propose ALMA B5 observations to measure two key tracers of dense molecular gas, HCN and HCO+ (J=2-1), for two local (z<0.2) LIRGs, optically classified as Sey 2. Previous studies assessed the effect of AGN activity with respect to the star formation (SF) onto the molecular gas via CO-SLED studies on galactic scales. To make a significant step forward in our understanding of the AGN effect on ISM, we need to spatially resolve the nuclear regions at the scale of GMCs (~40pc), to assess the XDRs vs PDRs relative contributions. This study will take advantage of the characterisation of the sources in terms of AGN intrinsic power and obscuration level from our X-ray analysis. These provide the key inputs to photoionisation models, and will allow us to interpret the ALMA data on a solid physical ground, in terms of relative importance of AGN and SF. The comparison of spatially resolved HCN/HCO+ between different molecular line transitions will reveal the nature of the radiation field impinging on the GMCs surface. The required high-spatial resolution also enable us to probe the internal dynamics and structure of these highly obscured systems, since HCN-VIB emission is optically thin. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-02-02T00:00:00.000 |
| 2867 | 2021.1.00026.S | 10 | Multi-band sub-THz observations in NGC 1068: A test of the Unified Model of AGN | The active galactic nucleus (AGN) is one of the most energetic phenomena in the universe and may have played a fundamental role in galaxy formation. The Unified Model of AGN has been proposed and favored to explain the large variety of AGNs. Nevertheless, the underlying principle is yet unclear because the putative dust torus proposed in the model is not observationally confirmed due to the lack of pc-scale, sub-THz continuum observations to trace the amount of cold-to-warm dust in AGNs. Here we propose sub-THz (Band 8 and 9) observations in the center of NGC 1068, a Type-II Seyfert galaxy, down to 2-3 pc for possibly the first direct observational evidence of the dust torus. We test if sub-THz continuum emission of the AGN is associated with the dust torus from partially-resolved continuum images and a radio-to-infrared spectral energy distribution (SED) fitting. We also obtain CO J=6-5 and J=4-3 line emission at the same time for an independent physical constraint of the torus. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-06-13T02:45:11.000 |
| 2868 | 2015.1.00388.S | 151 | A Spectral Line Snapshot Proposal for ALMA: Characterizing Star Formation Rates and Surface Densities of High-redshift Galaxies | We propose a spectral-line "snapshot" program with ALMA to obtain (a) the [NII] 205 um line fluxes of 7 galaxies and the CO(7-6) line fluxes of 5 galaxies to complete the [NII] and CO(7-6) data for a sample of 8 luminous galaxies at z = 4 to 5, and (b) the [NII] 205 um line fluxes of 4 L*-class galaxies at z ~ 5.5, with sub-solar metallicities. The [CII] 158 um line fluxes are available for all these galaxies. The data set of (a) will be used to validate, up to z = 5, a method of using (i) the CO(7-6) line luminosity as an accurate and robust star formation rate (SFR) measure and (ii) the [NII]/CO(7-6) (or [CII]/CO(7-6)) flux ratio as a useful estimator of the far-infrared (FIR) color (thus, the dust temperature or SFR surface density). The [NII] data of (b) would represent the first detections of this line in L* galaxies at z > 5, and will be used with the [CII] data to quantitatively constrain the FIR colors of these galaxies and provide an independent assessment of their metallicities. The outcome of this porposal will lay the ground work for using this simple spectral line method to survey or study the SFRs of high-z galaxies in the coming ALMA era. | Galaxy structure & evolution | Galaxy evolution | 2017-03-02T20:13:49.000 |
| 2869 | 2023.1.00499.S | 0 | Studying CO SLEDs of local LIRGs at 100 pc resolution | This program targets 12m+ACA observations of the CO (4-3), (6-5), (7-6), and (8-7) molecular gas line emission and continuum emission in bands 8 to 10, of a sample of 6 U/LIRGs. The main purpose of these observations is to recover and map the distribution of the warm gas at mid J transitions of these galaxies for the first time at ~ 100 pc resolution, a factor of ~60 improvement in resolution compared to existing Herschel observations. We will reveal for the first time the morphology of the highest excitation CO gas that can be accessed from the ground, and along with matched resolution lower J CO archival observations will provide the highest resolution low to mid-J CO SLED in local U/LIRGs. Modeling such SLEDs will provide accurate estimates of the density and temperature of the gas and overall mass distribution at 100 pc scales. These galaxies all have archival or approved JWST observations of mid-infrared vibrational molecular gas lines (H2), which will allow us to perform a multiphase census of the interstellar medium in local U/LIRGs at an unprecedented spatial resolution unachievable with previous IR observatories. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 2870 | 2013.1.00662.S | 14 | Orion 2 & 3 mapping | We propose to map the massive quiescent filament in Orion in the dust band 4 continuum and the dense molecular tracers N2H+, CH3CN, HC3N, and HNC in band 3. With the unparalleled ALMA sensitivity and UV coverage we will sample scales from the pc-scale filament to 10^3 AU dense gas cores, resolving the thermal Jeans length. This will be the most complete gas and dust study with unprecedented fidelity from 2 arcsec to 20 arcmin. Thus, we will obtain precise measurements of the distribution of temperature, density, kinematics, and mass in OMC2/OMC3; characterizing the dynamical and chemical environment in Orion. These fundamental measurements will help us understand the interplay relation dense cores and the fragmentation of filaments, producing the most accurate CMF in the process, and likely finding for the first time the "first hydro-static cores" in a massive star formation region. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-12-07T18:27:42.000 |
| 2871 | 2021.1.00629.S | 63 | The C content of debris disks around young A-stars | A growing number of debris disks are found to contain gas, but the origin and evolution of this gas is not well understood. We propose to acquire ALMA data of CI emission towards seven debris disks. By combining our observations with archival data, we will get a complete census of the C and CO gas content of a volume-limited sample of bright debris disks around young A-stars. This will allow us to study the relation between C, CO and the dust on a statistical level for the first time. By comparing the fluxes and spatial distributions of C, CO and the dust, we will test models of secondary gas production, viscous evolution and chemistry of gaseous debris disks. Our survey will provide new insights into the early evolution of planetary systems and help to bridge the gap between protoplanetary disks and mature planetary systems such as the Solar System. | Debris disks | Disks and planet formation | 2023-04-29T17:50:13.000 |
| 2872 | 2016.1.00777.S | 73 | Nucleosynthesis Enrichment in a Cosmic Yo-Yo | IRAS 13120-5453 (nicknamed "The Yo-Yo") is the second closest Ultra Luminous Infrared Galaxy (ULIRG) at a distance of 135 Mpc. In Cycle 2, we used ALMA to observe several CO lines at a resolution of ~0.35". The 12CO(3-2) and (6-5) integrated maps show a bright nucleus with a slightly extended coccon of emission. The 13CO(1-0) integrated map shows an interesting morphology, a ring. The 13CO emission is depressed within the nucleus while the C18O emission is quite bright everywhere highly suggesting massive star nucleosynthesis enrichment of the interstellar medium (ISM) within the Yo-Yo. We propose to observe multiple isotopolgues of several different species to look for other tracers with a similar morphology to test whether massive star nucleosynthesis enrichment of the ISM is responsible for the structure. | Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-05-23T02:35:04.000 |
| 2873 | 2013.1.00584.S | 12 | Characterizing the Earliest Phases of Massive Star Formation in Cold Core Objects detected with Planck | IRDCs, seen in extinction against the mid-IR Galactic background, are thought to be the sites of massive star formation. The IRDC samples are however very biased by the detection method, which requires a bright background such as the inner Galaxy. Herschel and Planck, which operate in the far-IR and sub-mm, can detect massive clouds in emission throughout the Galaxy. This offers the opportunity to search for massive star forming clumps in the outer Galaxy and to investigate whether their physical structure, fragmentation, star formation efficiency, and gas dynamics are similar to those found in IRDCs. G191.51-0.76 is a cold core detected with Planck in the outer Galaxy. It has a network of filaments converging into a central massive clump (hub-filament system), and it does not show 70 micron sources making it a precursor of previously reported hub-filament systems such as IRDC SDC13. We propose to mosaic the continuum and N2H+ and HNC (1-0) emission toward G191.51-0.76 with ALMA Band 3 to determine its physical properties, fragmentation and gas dynamics. These results will provide key information about the dependence of massive star formation with Galactic disk location. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-06-20T06:26:07.000 |
| 2874 | 2022.1.00545.S | 10 | Resolving GMC Scales and Clumpy Galaxy Formation in the Most Massive Halo in the Reionization Era | We propose to image the dust and CII emission in the central galaxies of the most massive halo known in the epoch of reionization at the highest possible spatial resolutions with ALMA, SPT0311-58 at z=6.900. This target is the only z>6 system bright enough to push to 15km baselines, and is the target of multiple JWST Cycle 1 imaging and IFU programs and deep HST imaging. The structure is anchored by a pair of ultramassive merging galaxies resolved into a chaotic and clumpy rapidly-assembling structure in existing ~0.08" dust and CII ALMA data. The proposed 0.02" observations will resolve the size and mass scales of Giant Molecular Clouds seen at lower redshift. We will determine whether any of the currently-known CII clumps breaks up into smaller substructures at <100pc resolution, constrain the internal kinematics of the clumps to determine their origins, and connect the clumps to z=0 GMCs. SPT0311-58 is the only reionization-era target for which such high spatial resolution is feasible, and will illuminate the formation of early massive galaxies on GMC scales in unmatched detail. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2024-08-17T03:54:52.000 |
| 2875 | 2016.1.00970.S | 16 | The innermost region of an accretion disk around Source I | We propose a high resolution (0.04"=16.8 AU) imaging of the vibrationally excited H2O lines toward a rotating disk around a high-mass YSO Source I in Orion KL. In ALMA cycle 2, we detected the 498 GHz vibrationally excited H2O line with a 0.12" resolution and found a linear velocity gradient along the disk. The radial velocity in the PV diagram also shows a gradual increase toward the central position which agrees with the Keplerian rotation. On the other hand, high velocity features disappear at the central 0.08" region in diameter, suggesting a central hole. A possible signature of the hole is marginally resolved in the moment 0 map of the 498 GHz H2O line. However it turns out that the optically thick H- free-free continuum emission at band 8 could obscure the innermost region of the disk. In order to overcome this problem, we found that the H2O lines at band 10 (841 GHz and 854 GHz) are the best probes because of the lower H- free-free opacity. We will reveal the 3D geometry (diameter, thickness, hole), velocity field, temperature/density profile, disk mass, and possible origin of the central hole (ionized disk, HCHII, or accretion shock) in Source I. | High-mass star formation | ISM and star formation | 2019-10-31T00:23:38.000 |
| 2876 | 2016.1.01138.S | 17 | Probing the Most Extreme Star Formation at High Redshift Through Direct Observation | The chemical enrichment and reionization of the Universe were likely driven by intense starbursts at early times. However it has become clear that such galaxies in the distant Universe do not constitute a single, homogeneous population; detections of line and continuum emission at z>5 show a range of gas masses and star formation efficiencies. Here we aim to test the hypothesis that a high surface density of star formation, and hence a similarly high inferred gas surface density, may be key to the way in which a high redshift, star forming galaxy retains and illuminates its non-stellar baryonic components, and hence to whether or not ALMA can detect such a source. We will observe three spectroscopically-confirmed z~5 galaxies in the CO(5-4) rotational transition, observed in band 3. Our targets are not typical Lyman break galaxies, but instead are selected for exceptionally high surface densities of star formation, as traced in the rest-frame ultraviolet. We will compare the millimetre properties of these targets with similar Lyman break galaxies to determine whether they show a higher gas mass and hence are easier to recover than more typical LBGs. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2018-06-03T15:15:31.000 |
| 2877 | 2017.1.00560.S | 19 | Unveiling dusty star-forming galaxies and probing multiple AGN within a giant Lyman-alpha nebula at z=3.167 | In the hierarchical model of structure formation, giant elliptical galaxies form through merging processes, within the highest density peaks known as protoclusters. Usually, radio galaxies pinpoint the location of these young protoclusters. However, as part of a campaign to map Lyman-alpha around radio-quiet quasars, we have discovered three giant (>200 kpc) nebulae that host multiple AGN and are surrounded by overdensities of Lyman-alpha emitters. These regions are prime candidates for massive protoclusters in the early stages of assembly. To search for ultraluminous starburst activity within these unique structures, we have initiated a submm programme with single-dish telescopes (e.g. APEX). Intriguingly, our first targeted large-scale structure at z=3.167 showed strong emission at 870 micron. To firmly characterize the source(s) of this emission and known companion objects, we propose here to use ALMA to conduct sensitive observations in band 4 targeting the CO(5-4) line emission and the underlying continuum. These observations will open the path to a detailed analysis and comprehension of the progenitors of elliptical galaxies. | Lyman Alpha Emitters/Blobs (LAE/LAB), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2019-04-03T18:55:14.000 |
| 2878 | 2019.2.00143.S | 27 | SED Constraints for a candidate high-z 2mm-selected DSFG | The accurate census of dusty star-forming galaxies (DSFGs) at z>4, where their number density is currently unconstrained, requires a spectroscopically-complete sample of DSFGs with uniform selection. This has not yet been achieved for surveys sensitive to the z>4 obscured Universe despite decades of effort. Our team has recently conducted the first 2mm blank field survey with ALMA and found 12 sources at >5sigma significance in a 155arcmin^2 area; our goal is to filter out the foreground of fairly-common 1 | Sub-mm Galaxies (SMG) | Galaxy evolution | 2022-05-13T00:00:00.000 |
| 2879 | 2017.1.00002.S | 55 | Why is the galaxy NGC4945 extremely CN-luminous? | NGC4945 is the southern starburst galaxy that is nearby (D<5Mpc), provides strong molecular line emission, and also contains a Seyfert 2 nucleus. Its integrated intensity ratio between CN(1-0) and HCN(1-0) (~2) is one of the highest ever measured in a galaxy, yet the reason is still unknown. CN can be overproduced in both starburst and active galactic nucleus (AGN) environments, but the lack of previous spatially resolved CN and HCN observations in NGC4945 prevent us from linking the ratio to the coexistent nuclear activities. We propose to observe the two transitions of CN, HCN, HCO+, and CO in Bands 3 and 6 with a matching angular resolution of 1.0" (~26 pc, at least 3 times better than any previous study in this galaxy). We plan to (a) resolve its central 2" AGN component for the first time, and to study the intensity distribution of the species to understand where and why CN is so efficiently formed; and (b) study the kinematics of the nucleus, looking for signatures of inward and/or outward gas flows. ALMA is the only telescope able to provide the required angular resolution and sensitivity necessary to study the chemistry and physics in the central parsecs of this galaxy. | Galaxy chemistry | Galaxy evolution | 2019-10-15T11:10:32.000 |
| 2880 | 2019.1.01492.S | 11 | Radio jets or morphological quenching: What suppresses star formation in massive galaxies? | We will use ALMA at 3 mm at 1-1.5'' beam to probe CO(1-0) in the nearby (z=0.0755) massive spiral galaxy 2MASX J23453268-0449256, which has two giant radio lobes, but no bulge (<10% bulge fraction). This provides us with a rare and precious opportunity to study the gas kinematics in a radio galaxy without potential impact from the most important alternative mechanism discussed in the literature: Morphological quenching has been proposed to inhibit star formation in early-type galaxies simply by stabilizing the ISM through the spherical stellar gravitational potential, without need for feedback. We will compare the gas mass, gas fraction, and depletion time in J2345-0559 with those found in other samples of nearby early-type radio galaxies and galaxies in the field taken from the COLDGASS survey. Does this galaxy fall onto the Schmidt-Kennicutt relationship of ordinary (spiral) star-forming galaxies, or 1-2 orders of magnitudes below, like many nearby radio galaxies? Since we are probing a universal mechanism of galaxy evolution, answering this even for a single spiral galaxy will be a powerful test of the role for AGN feedback in galaxy evolution. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-02-12T05:20:44.000 |
| 2881 | 2022.1.00175.S | 10 | A Careful Calibration of New Molecular Feedback Tracers in the Early Universe | Recent studies with ALMA have led to a significant leap in our understanding of galaxy evolution in the early universe through the detection of clear signatures of feedback in massive starbursts at high redshift. The now most commonly employed tracer is the OH+ molecule, which now is detected in >20 galaxies at z=2-6. In the majority of cases, these studies show evidence for gas infall or outflows through red-/blueshifted lines and/or P-Cygni/inverse P-Cygni profiles. However, the current studies suffer from some limitations due to issues like line blending and mixing of different transitions, which may require different calibrations. We here propose to improve upon these biases by augmenting an existing study of 15 sources from the ACA to produce a sample with complete coverage of all three ground-state OH+ lines. Through simultaneous fitting of all transitions, we will be able to correct for any blending issues of individual transitions, to compare the optical depth tau_OH+ of all transitions, and to investigate the recently discovered scaling relation between tau_OH+ and the dust temperature - as is necessary to more reliably translate the measurements to feedback properties. | Starburst galaxies | Active galaxies | 2024-04-05T11:47:21.000 |
| 2882 | 2016.1.00711.S | 13 | Density contrast in the episodic outflow from the protostar TMC1A | In this program, we will study the density contrast in episodic outflow knots emanating from the Class I protostar TMC1A. These knots, recently detected at unprecedented 6 au resolution in our ALMA cycle 3 observations, may represent overdense gas in the outflow directly linked to accretion bursts from the disk onto the protostar. We propose to observe the high-density tracer molecule HCN at the same angular resolution as we did CO in Cycle 3. The intensity ratio of HCN to CO lines is a sensitive probe of molecular gas density. The density is a crucial quantity necessary to measure the ejected mass and momentum. Together with the resolved spacing between the knots, we will be able to study the launching engine at the surface of the disk and/or the protostellar surface. Sophisticated radiative transfer modeling and numerical, magnetohydrodynamic simulations are at hand within the team for a quantitative interpretation of the results. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-02-26T20:50:45.000 |
| 2883 | 2016.1.00804.S | 143 | Radio-luminous AGN through ALMA's eyes: What is the effect of luminous radio activity on star formation? | One of the oustanding issues in the formation and evolution of galaxies is a definitive measurement of the impact that AGN have on Star Formation (SF). In the local Universe there is clear evidence that radio-luminous AGN (RLAGN) suppress SF in massive galaxies. However, in the distant Universe the picture is more mixed, with reports for RLAGN suppressing, enhancing, or having no impact on SF! A major issue is the lack of sufficiently deep FIR-submm observations to measure the SF properties of a sample of typical distant RLAGN. The primary aim of this proposal is to build on our earlier ALMA programme of X-ray selected radio-normal AGN and measure individual SF rates (SFRs) for a complete sample of RLAGN over the same key range in redshift as our radio-normal AGN (z=1.5-3.2). With the proposed observations we will directly compare SFR and specific SFR (SFR per unit mass) distributions of RLAGN, radio-normal AGN, and SF galaxies to search for evidence of suppressed or enhanced SF in the hosts of the RLAGN, compared to X-ray AGN, and the SF galaxies of similar mass and redshift. We will also explore claims that extended RLAGN have lower SFRs when compared to compact RLAGN. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-02-16T19:32:20.000 |
| 2884 | 2019.1.01832.S | 261 | On the Spectral Energy Distribution of Dusty, Star-Forming Galaxies: the nature of the dust temperature evolution. | The far-infrared spectral energy distributions (SEDs) of galaxies are poorly constrained by data beyond z~2; most dusty star-forming galaxies (DSFGs) may only have 2-5 photometric measurements along the dust continuum, providing only a notion of their dust temperatures and total IR luminosities. While Herschel-SPIRE (250-500um) filled in the SEDs of DSFGs at 02 suffer from very low signal-to-noise detections in the Herschel bands. Recent theoretical work suggest that galaxies' dust SEDs might be significantly hotter at higher redshifts, though this has not been verified observationally. We propose to obtain ACA stand-alone Band 8 (630um) observations in a relatively large sample of ~30 dusty star-forming galaxies at z=2-4 whose Herschel data is not constraining; the extra photometric point at a higher frequency than SCUBA-2 provides a crucial lever arm on their SEDs. We will use the SED constraints to infer the average relationship between IR luminosity and dust temperature (lambda_peak) for moderate luminosity DSFGs at 2 | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-03-23T16:38:44.000 |
| 2885 | 2024.1.00579.S | 0 | Quest for the formation mechanism of the molecular cloud by the relativistic jet | Microquasars are high-energy objects with relativistic jets that release vast amounts of energy into space, significantly impacting on the surrounding interstellar medium. However, their astrophysical natures remain obscured. Based on previous observations and theoretical studies, it has been proposed that jets from microquasars sweep up neutral atomic hydrogen gas, leading to the formation of molecular clouds. In this proposal, we aim to spatially resolve the density and velocity structures of the interstellar molecular clouds surrounding the microquasar candidate HESS J1023-575's jet and directly compare them with theoretical models. This will significantly advance our understanding of the formation process of molecular clouds through the interaction of relativistic jets with interstellar gas. Previous studies have only achieved spatial resolutions of 2-3 pc, unable to resolve structures corresponding to 1 pc scale jets injected by theoretical models. Our proposal aims to use ALMA ACA Band 3 to spatially map the entire molecular cloud surrounding the jet with a resolution of less than 0.5 pc, enabling the first legitimate comparison with theoretical models. | Outflows, jets and ionized winds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 2886 | 2015.1.01388.S | 75 | Tracing the Initial Conditions for Massive Star Formation in the Prominent H II Region N 113 in the Low-Metallicity LMC | We propose to image one of the most prominent star formation regions in the Large Magellanic Cloud N 113 at a 0.2 pc resolution with ALMA in the molecular transitions that probe a wide density range (10^2-10^7 cm^-3) to study both the dense clumps/cores and the lower density gas in the interclump regions. ALMA is the only instrument that can provide high enough angular resolution to resolve the clumps and their embedded cores in the LMC. A combination of the 12CO(2-1), 13CO(1-0) and (2-1), C18O(1-0) and (2-1), CS(2-1) and (5-4), HCO+(1-0), HCN(1-0), H13CO+(1-0) and (3-2), H13CN(1-0) and (3-2), SiO(6-5) lines will allow us to investigate physical conditions and kinematics of the molecular gas at great detail, and detect outflows. We will also probe the physical properties and dynamics of the ionized gas using the H30a and H40a radio recombination lines and dust with 1 mm and 3 mm continuum. By combining the proposed ALMA data with a wealth of multiwavelngth data already available for N 113, we will build a comprehensive picture of the interstellar medium gas phases and dust within N 113 to study the initial conditions for massive star formation in a low-metallicity environment. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2017-07-05T23:12:41.000 |
| 2887 | 2016.1.00988.S | 23 | A Tale of Two Cores: Kinematics and Astrochemistry in Massive Cores with Cold Gas Tracer ortho-H2D+ | We propose to observe ortho-H2D+ in two massive starless/early-stage cores to provide stringent tests of global chemo-dynamical models that can distinguish between slow and rapid collapse, relative to free-fall. This species also has the potential to probe the structure and kinematics of higher density, higher depletion zones within the cores, compared to our Cycle 0 and Cycle 2 ALMA observations of N2D+(3-2). ortho-H2D+ is the first step in deuterium fractionation. It gives strongest constraint on the crucial value of ortho-to-para H2 ratio. In addition we will detect dust continuum emission from the core, complementing our Band 6 observations. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2019-08-16T00:00:00.000 |
| 2888 | 2015.1.01296.S | 47 | Collisional star-formation in the SMC: NGC346 | The NGC346 open cluster, and the entire HII region N66, are clearly exceptional in the context of the ensemble of otherwise rather benign star-forming regions in the SMC. Accounting for 6% of the total current-era star-formation within the SMC, NGC 346 harbours upwards of 30 O-type stars; more than half the entire SMC O-star population, as well as a number of young stellar objects and pre-main sequence objects. We propose here mapped observations of the molecular clouds associated with N66, at the 1-0 and 2-1 transitions of both 12CO and 13CO. Following existing techniques in the literatue, these data will be sufficient to derive a usefully-constrained solution to the Radiative transfer equations, and yield resolved maps of both the excitation temperature and molecular cloud number density}. We will then have sufficient information to determine the energy density within the cloud population. The measured energy density larger will be contrasted with that typically associated with cold and dense molecular clouds (30K, and No~10^4 cm^-3) where a significant excess would suggest a evolution involving a kinetic, filament-filament interaction. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-09-28T20:52:02.000 |
| 2889 | 2013.1.00498.S | 27 | Dust growth in protoplanetary disks: where in the disk are grains growing? | The first step toward planet formation is the growth of submicron grains into centimeter-sized particles inside a circumstellar disk. The long-wavelength emission from large dust is the last observable link in the growth chain from interstellar dust grains to fully fledged planets. Thus, observations of this phase provide crucial constraints to theories of early planetesimal growth and of the transport and evolution of dust particles. In this proposal we request ALMA observations at 1.3 mm, that when combined with our existing 0.7 - 1 cm spatially resolved observations, will determine where in the disk are dust grains preferentially growing. With careful characterization of the disk thermal and density structure we can determine the dust optical depth and constrain the dust emissivity index throughout the disk. These ALMA observations will establish if spatial variations of grain growth occur in nature, as it is expected from several theoretical scenarios, like particle trapping at pressure maxima arising from vortices, turbulence, or Rossby-wave instabilities. | Disks around low-mass stars | Disks and planet formation | 2016-12-01T03:17:31.000 |
| 2890 | 2019.1.01184.S | 26 | Clarifying CI distribution in molecular cloud by absorption observation toward compact quasars behind the Milky Way | We propose to perform [CI] absorption observations toward two compact quasars, J1851+0035 and J1935+2031, behind the Milky Way (MW). High-resolution ALMA beam toward QSOs can reveal the internal structure of a molecular cloud in the MW at a scale of ~100AU. Many observations found that [CI] distributions are similar to those of CO against the prediction by the classical photo-dissociation region (PDR) model. A model that molecular cloud consists of many clumps so as UV radiation can penetrate into the cloud, called clumpy PDR model, is suggested, although being unproven. Recent ALMA observations revealed that molecular clouds traced by CO are composed of many small clumpy structures. Investigating the consistency of the spectral features between [CI] and CO and PDR probes, we will reveal [CI] structure and UV effect within a molecular cloud so as to verify the clumpy PDR model. Unless we found the consistency, the effect of turbulence or chemical evolution should be considered. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2022-05-21T16:26:06.000 |
| 2891 | 2019.1.00919.S | 5 | Are disks around post-AGB binaries second generation protoplanetary disks? | ALMA revealed the detailed morphology of protoplanetary disks showing a lot of structure in the dust distribution (e.g. gaps, spirals). At the other end of the HR diagram, post-AGB binaries are also surrounded by disks of dust and gas. Those disks were formed from matter ejected in a strong binary interaction process at the end of the AGB phase. Despite a very different formation process post-AGB disks share several properties with protoplanetary disks such as similar infrared excesses, inner rim physics and dust grain growth. This raises the question of the planet formation efficiency across the HR diagram. With this proposal we aim to make a pilot observation of one of the best-studied disks around a post-AGB binary system to reveal its structure in the continuum and compare it to protoplanetary disks. Together with infrared direct imaging and interferometric observations, these ALMA observations will help us to constrain the disk structure around the prototype of post-AGB binaries at multiple wavelengths and spatial scales. In the case of the detection of asymmetric feature new light will be shed on these intriguing second-generation protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2022-10-31T22:30:29.000 |
| 2892 | 2017.1.01639.S | 1169 | Measuring the mass budget of Proto-Tatooine Systems | Planet hunting surveys have recently unveiled planets circling tight binary stars, often referred to as Tatooine-like systems. The origin of these systems is not fully understood, and requires knowledge of the protoplanetary disks out of which they formed. Prior surveys of disks around binaries have found that the presence of a medium separation binary (~10-300au) can severly diminish the dust mass, but have limited statistics for the tight binaries (<10 au separation) that are characteristic of Tatooine-like systems. If tidal effects are the only source of binary influence on a disk, then the reservoirs of cold dust/gas among these tight binaries should be similar to those around single stars. Taking advantage of recent observations with high-resolution multi-object optical and near-infrared spectrographs, we have compiled a list of ~150 double-line spectroscopic binaries in Orion and IC 348. Sub-mm dust continuum observations of these systems, with sensitivity of 1-2Mearth, will detect any significant disk mass, providing a statistically robust sample of protoplanetary disk masses among tight binaries that has not been available in the past. | Disks around low-mass stars | Disks and planet formation | 2019-12-14T21:54:34.000 |
| 2893 | 2016.1.00298.S | 3 | Constraining the temperature and heating mechanisms in the solar plage chromosphere | The chromosphere of the Sun in solar plage regions, areas with a strong unipolar magnetic field, requires a heating input of ~20 kW m-2. This is a factor five higher than for weakly magnetized quiet Sun areas. The temperature structure of the plage chromosphere is poorly understood and the magnetic-field-mediated heating mechanisms are unknown, even though many theories exist. We propose to use ALMA with co-observations with the IRIS satellite to observe solar plage. We will analyse the data with an non-LTE inversion code to derive the temperature structure of the chromosphere and so address the following questions: 1) What is the temperature structure of the solar plage chromosphere? 2) What are the mechanisms that lead to the large heating of the plage chromosphere compared to the quiet Sun? The ALMA data are essential for answering these questions. Only by including them in the inversions (and by combining them with atomic line data in the UV) is it possible to correctly retrieve the temperature structure in plage regions. | The Sun | Sun | 2019-08-06T13:58:36.000 |
| 2894 | 2019.1.00652.S | 22 | Dust and CO components within star-forming galaxies with different gas metallicities at z~3.3 | Observational results from gas metallicity measurements for star-forming galaxies suggest the presence of the prominent gas inflow at z>3. To understand how the gas accretion affects star-formation activity and interstellar medium conditions at z>3, investigating the molecular gas reservoir within galaxies is essential. Dust continuum is often used to estimate gas mass of galaxies from low to high redshifts. However, it remains unclear whether the locally calibrated relations are applicable for star-forming galaxies at z>3 with low metallicity typically. For an unbiased view of molecular gas contents of galaxies, not only dust emission observations but also CO emission line observations are necessary. We propose to observe CO(4-3) at Band-3 for the two massive star-forming galaxies at z~3.3, which were observed at Band-6 in our cycle 6 program and have estimates of the dust continuum. The two galaxies have similar stellar masses but different gas metallicities. This proposal will allow us to test the empirical relation using dust emission for galaxies with different metallicities, and to investigate their depletion timescale and the presence of inflow/outflow signatures. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2021-06-17T08:12:43.000 |
| 2895 | 2016.1.01164.S | 31 | An unbiased survey of disk structures in Taurus | Some of the most impressive ALMA observations have been of targets selected based on deficits in mid-IR dust emission, indicating the presence of a cavity. However, every ALMA observation with sufficient spatial resolution and sensitivity has indicated clear radial (and often azimuthal) structures in the disk. Similarly, SMA observations previously revealed dust cavities in mm-sized grains that were not identified in the IR, with small grains filtering into the inner disk. Dust traps, seen as rings and cavities, may be common to all disks - with detections limited only by spatial resolution and sensitivity. We therefore propose a survey of protoplanetary disks in Taurus, unbiased to any pre-selection based on disk structure, to search for dust rings and cavities in protoplanetary disks. The power of this program is not only the unbiased census of disk structure, but also in connecting the distribution of mm-sized grains and cold gas to disparate observational phenomena (inner disk structure, jets, accretion) using the extensive data already in hand for Taurus. These comparisons will allow us to test how age and viscosity affects the size and location of disk structures. | Disks around low-mass stars | Disks and planet formation | 2019-02-02T20:06:29.000 |
| 2896 | 2016.1.01499.S | 154 | The Dynamics and Structure of Dusty Starbursts in the First 1.5Gyr | The ISM in the most massive galaxies at high redshifts was substantially different than the ISM of star-forming galaxies today. While the most intense bouts of star formation occurred in dust-enshrouded objects, models of galaxy formation have great difficulty in forming realistic populations of galaxies that simultaneously match observed number counts and other galaxy properties. Here, we propose 0.2" resolution observations of the [CII] 158um emission line in 8 z>4 gravitationally lensed galaxies selected from the SPT 1.4mm survey. By reconstructing the [CII] emission on scales of ~200pc and 25km/s, we will determine valuable structural parameters of the ISM, including the pressure, cloud sizes, stability parameter, and global kinematics. By comparing with maps of the continuum (tracing star formation) at the same resolution, we will explore the gas depletion timescales and local Kennicutt-Schmidt relation. Finally, we expect to detect on the order of one additional continuum source and one additional line source at the same redshift as the primary galaxy in every pointing, yielding valuable information about the clustering of extreme star-bursting galaxies at high redshift. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-07-27T02:24:25.000 |
| 2897 | 2023.1.00527.S | 0 | Decouple ion RRLs of Helium, Carbon, and Oxygen in the Orion KL-M42 region | Recently, radio recombination lines (RRLs) of ions heavier than helium are detected for the first time, during a survey towards Orion KL using the TianMa 65-m Radio Telescope. It is also for the first time to detect ion RRLs towards a star formation region, allowing an unprecedently accurate measurement of the abundance of C^{2+} and/or O^{2+}. However, it is difficult to further distinguish between C+ RRLs and O+ RRLs using single dishes since they have close rest frequencies. Different kinds of ions have different ionization energies, and ionized ions of different species thus have different distributions within an ionized region. It provide us an opportunity to decouple RRLs of different kinds of ions. ALMA band 1 is the only equipment to achieve this goal. Thus, we propose to mosaic the whole Orion KL-M42 system (~4*4 arcmin^2) to decouple their He+, C+ and O+ RRLs. | Inter-Stellar Medium (ISM)/Molecular clouds, HII regions | ISM and star formation | 2025-05-07T02:42:22.000 |
| 2898 | 2017.1.00928.S | 67 | Mapping Jet-ISM Interactions in X-ray Binaries | Relativistic jets launched from accreting black holes carry large amounts of energy and matter into their surrounding environment. Black hole X-ray binaries (BHXBs), the stellar-mass analogues of active galactic nuclei (AGN), are ideal targets for studying the interactions between the jet and the ambient ISM in detail, due to their close proximity and the rapid timescale evolution of BHXB jets. Identifying and probing the ISM properties in interaction zones provides insight into highly sought-after jet properties, such as the total jet power, composition, duty cycles, and the efficiency of jet feedback. We propose targeting the candidate interaction sites around the BHXBs, GRS 1758-258 and 1E 1740.7-2942, with Band 3 ALMA ACA observations. We will map the CO, SiO, CS, HCO+, HCN, and HNCO line emission over 4.5 square arcmin for each target (our targets are within 5 deg, and can thus be observed in a single execution). As these lines provide for excellent diagnostics of shock energetics and ISM excitation, we can definitively test whether these candidate zones are powered by a BHXB jet, and, if the association is confirmed, measure the injected jet power through calorimetry. | Outflows, jets and ionized winds, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-07-11T00:00:00.000 |
| 2899 | 2015.1.00697.S | 115 | Peering into the ejecta of SN1987A: chemistry, clumpiness and nucleosynthesis | Supernovae are dust and molecule factories. Molecules chemically control the onset, composition, and mass of dust, and CO and SiO were observed in several supernovae a few months after the explosion. Some molecules, such as SiO, are dust precursors, while others, like CO, do not get incorporated in grains and survive until the remnant phase. Chemical kinetic models predict that other molecules will also be present in the ejecta. Based on these model predictions and the excitation conditions in the ejecta of the young supernova remnant SN1987A, SiS and SO, in particular, should have bright emission lines at mm wavelengths. We propose to observe SN1987A in Bands 3 & 4, and will focus on the SiS, SiO, SO, and SO2 species to probe the chemistry and physical conditions in the ejecta. Our observations will also include isotopologues of SiS, SiO, and SO, to trace the regions where molecules form, the degree of clumpiness in the various zones of the ejecta, and the nucleosynthesis of massive stars. This is a completely revised and updated proposal based upon the cycle 2 proposal numbered 2013.1.00334.S. | Supernovae (SN) ejecta | Stars and stellar evolution | 2017-08-25T17:34:26.000 |
| 2900 | 2022.1.01695.S | 10 | Zooming-In on the Planet Formation Process in PDS70 | Hosting two protoplanets, the PDS70 system offers a truly unique opportunity to directly confront planet formation theories and witness first hand the complex interplay between young planets and host disk. As the benchmark system for the field of planet formation and the only disk known to host examples of circumplanetary disks, extremely high angular resolution observations, achieving spatial resolutions of 12 mas (1.4au), would yield a dataset with which to place our theoretical understanding of the planet formation process on an observational footing. In particular, by spatially resolving scales comparable to the local pressure scale height in the inner disk for the first time, these observations will allow us to probe fundamental properties of the system such as the size of the circumplanetary disk, the morphology of mm-sized dust emission in the terrestrial planet forming region and the fine-grained structure of the outer dust ring, enabling much needed anchor points for theoretical models. This proposal aims to take full advantage of the longest baselines afforded by ALMA to probe the planet formation process in the greatest level of detail possible. | Disks around low-mass stars | Disks and planet formation | 2024-03-10T10:20:19.000 |
| 2901 | 2015.1.00791.S | 22 | Probing the Final Stage of Protoplanetary Disks Evolution: Gas Clearing Time-scales and Debris Disk Formation | The evolution of circumstellar disks from their gas-rich protoplanetary to gas-poor debris stages is not well understood. Photoevaporation models are often invoked to explain this process but the mass-loss rates predicted by different models do not agree, resulting in uncertain time-scales for the final stages of disk clearing. The best candidates for studying this final stage are weak-line T-Tauri stars (WTTS) with an IR excess caused by circumstellar material. In a recent paper based on ALMA data, we studied a sample of these WTTS disks and find they are an inhomogeneous group, displaying very different properties. Many of the WTTS disks contain dust masses low enough to remain undetected in continuum, suggesting they may be debris disk analogues. A few rare disks were detected in continuum and may be photoevaporating disks, but their CO remains undetected, preventing a conclusive characterisation. We here propose to conclusively characterise a selection of these WTTS disks with observations in Bands 3 and 6 continuum, and 12CO(2-1). These results will have profound implications for disk evolution, giving new constraints to dissipation time-scales and disk evolution models. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2017-06-07T22:02:06.000 |
| 2902 | 2019.1.01641.S | 57 | CNO isotopes as probes of the IMF and chemical enrichment of galaxies | We have successfully demonstrated (Zhang et al. 2018, Nature) how the unprecedented sensitivity of ALMA, coupled with recent advances in stellar nucleosynthesis theory and detailed galactic chemical evolution modelling, allows for the use of specific CNO isotope ratios as sensitive probes of the initial mass function (IMF) in dust-shrouded starbursts. In previous work we have been mostly concerned with 13C/18O ratios. With this proposal we request ALMA observing time to collect high-sensitivity, homogeneous C18O/C17O ratios for a representative sample of galaxies at different evolutionary stages spanning a range of metallicity (from 0.2 to ~3 times solar) and star formation rates (from low-level regimes to high rates in starbursts). A few extant observations suggest a trend of increasing 18O/17O with increasing infrared luminosity. Since 17O is mostly produced in low- and intermediate-mass stars, while 18O is solely a product of massive stars nucleosynthesis, when coupled with our chemical evolution models well-benchmarked against the Milky Way, our proposed C18O/C17O observations can be used as another, independent tracer of the dominant IMF in galaxies. | Dwarf/metal-poor galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Local Universe | 2022-09-03T00:00:00.000 |
| 2903 | 2016.1.00369.S | 16 | Looking for a Keplerian disk in the very young protostar IRAS 4A | Circumstellar disks are essential to star formation. In the youngest protostars, Class 0 objects, magnetic fields can hinder disk growth if they are aligned with the rotation axis of the system. However, if the two are misaligned, then a large disk can grow. Current polarization observations are starting to probe magnetic fields down to disk (~50 AU) size scales. IRAS 4A is a unique Class 0 protostar in the sense that it is very young (~10 kyr), very bright, and very polarized (~15% at 8 mm). We postulate that the inferred magnetic field morphology seen at 8 mm by the VLA is indicative of rotating circumstellar material around the protostar. To confirm Keplerian motion, kinematic observations are needed. High resolution ALMA polarization observations of C17O and C18O, as well as the polarized dust continuum at 3 mm will allow us to both gather the kinematic information of the system, as well as make a useful comparison of the inferred magnetic field at 3 mm to that at 8 mm. | Disks around low-mass stars | Disks and planet formation | 2019-04-19T01:07:06.000 |
| 2904 | 2019.1.01693.S | 5 | Where is the outer disk? - First ALMA observations of an FS CMa-type star | We propose to observe HD 50138 with ALMA, first among the FS CMa-type stars, in order to resolve its circumstellar disk at mm wavelengths. FS CMa stars constitute an enigmatic group of B[e] stars, whose evolutionary state is uncertain. High resolution observations in the infrared confirmed the existence of disks around these stars. However, the nature of FS CMa stars is still poorly understood. Key questions still remain: Is the disk formed from the ejected stellar material? Are the FS CMa disks different from those around pre-main-sequence stars, regarding structure and chemical composition? If FS CMa stars are not young objects, their disks should have been built up from inside-out. This process is expected to produce small disks with low amounts of cold dust compared to protoplanetary disks. To test this hypothesis, we will observe HD 50138 with a resolution of 25 mas (9 au), 40 times better than the best current millimeter observation. Our aim is to determine the origin of the circumstellar material by measuring the size of the emitting region in the millimeter continuum and in the CO lines. We will also study the kinematics of the circumstellar gas and search for outflows. | Disks around high-mass stars | Disks and planet formation | 2022-09-27T16:36:53.000 |
| 2905 | 2021.1.00910.V | 0 | Connecting the black hole shadow and jet base in M87 | The supermassive black hole (SMBH) at the heart of the Virgo A galaxy (M87) powers one of the most well-studied relativistic jets in the sky. Due to its high mass and close proximity, M87 shows the shadow cast by the BH event horizon, and promises successful imaging of the jet launching mechanism with unprecedented detail. We propose 3 tracks of Band 6 VLBI observations with the EHT+ALMA VLBI array. The array improvements from Cycle 4 to Cycle 8 (inclusion of KP and NOEMA, together with a further optimized GLT) enhance the angular resolution and sensitivity. By accumulating multi-epoch imaging over multiple years, we can further refine the shadow feature both in total intensity and polarization. It will enable new tests of general relativity (GR) and models of powerful jet launching from a spinning BH with highly magnetized accretion flows. The observations will be accompanied by complementary (requested) 3mm observations with the GMVA+ALMA, together with a multi-band campaign including X and gamma rays up to the TeV regime. Ultimately, we aim to connect the smallest objects predicted by Einstein's GR to galactic-scale outflows that impact large-scale structures in the Universe. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-09-10T05:08:21.000 |
| 2906 | 2013.1.00493.S | 5 | Weighing Supermassive Black Holes with ALMA | Ubiquitely present at the centres of galaxies, black holes are central to understanding galaxy evolution. However, the correlations driving most theoretical efforts (e.g. black hole mass-central velocity dispersion relation) are based on a relatively small number of measurements and only a handful of methods. Our recent work with CARMA has however shown that it is possible to dynamically estimate the mass of supermassive black holes, by simply probing the near-Keplerian rotation of molecular disks around them at high angular resolution. This is a highly promising method, and in the ALMA era it will make possible hundreds of measurements across galaxies of all morphological types. In Cycle 2, it is already possible to exploit extended array configurations to measure the black hole mass in carefully selected objects. We therefore request here high angular resolution CO(3-2) line imaging of three promising targets spanning much of the Hubble sequence: NGC4429 (SA0), NGC4861 (SAab), and NGC3351 (SBb). With these data, we will probe their molecular gas kinematics on nuclear scales, weigh their black holes, and test the reliability of our measurement method. | Surveys of galaxies, Galactic centres/nuclei | Galaxy evolution | 2016-08-15T11:46:20.000 |
| 2907 | 2011.0.00199.S | 0 | Bursting Water Maser Feature in Orion KL | In February 2011, an outburst of the 22GHz H2O maser feature in Orion-KL has started after 13-year silence. This is the third time to detect such phenomena in Orion-KL, followed by 1979-1985 and 1998. In order to explore the origin of such enigmatic burst phenomenon, we have been carrying out astrometric observations of the bursting H2O maser feature in Orion-KL with VERA (VLBI Exploration of Radio Astrometry). We found the bursting maser is located at the Compact Ridge, suggesting that the maser burst is likely to be caused by the interaction with the outflow from the radio source-I and ambient dense gas. However, the physical properties in/around the bursting maser feature are not well understood because of the lack of observational studies except for the H2O maser itself. Furthermore, it is still unclear why only the 8km/s component(s) show such outburst episodically or with possible 13 year-periodicity. It may imply a special condition to stimulate such maser burst. One of the possibilities is an existence of unknown young stellar object in Compact Ridge, interacting with the outflow from source-I. In order to investigate the physical properties of the bursting maser feature and its origin, we propose monthly monitoring observations of the submillimeter H2O maser lines in parallel to our VLBI observations of the 22GHz maser lines. Based on our multi-transition observations of the H2O lines, we will constrain the physical properties of the bursting maser feature. In addition, we search for the submillimeter dust continuum source around the bursting maser feature. The current maser burst is the best opportunity to explore this burst event that may never come again for another 13 years and hence, our project is most suitable for the ALMA cycle 0. | High-mass star formation, Astrochemistry | ISM and star formation | 2013-06-14T03:45:00.000 |
| 2908 | 2022.1.01282.S | 56 | ACA mosaic search for dusty sources in and around the critical curves of Planck-selected strong lensing clusters | Exploitation of strong gravitational lensing cluster fields has recently surged based upon various multi-wavelength selection criteria, yet ALMA has yet to exploit the sub-mm selected cluster lensing fields. We request multi-band ACA Band 3,6,8 mosaics of 2x2 arcmin to map the entire lensing critical curve (magnification factors = 2 - 200) to trace the redshifted thermal dust emission from two sub-mm all-sky Planck-selected, cluster-lensed DSFGs at z=2.24 and z=2.66. By mapping the entire strong lensing magnification map we will characterize the rise in rest-frame dust emission from all counterparts within a physical area of about 1 sq. Mpc. Matched with wide-field imaging of multiple dust photometry points, we aim to estimate robust global molecular gas mass and SFR surface density maps to examine the distribution of gas/dust and the typical depletion time for counterparts in the vicinity of these massive, lensed DSFGs. This will showcase the ALMA ACA capability to mosaic wide-frequency ranges to leverage the recently discovered sub-mm selected lensing fields identified by the Planck satellite to detect galaxies out to the epoch of reionization. | Galaxy structure & evolution | Galaxy evolution | 2024-07-20T16:29:43.000 |
| 2909 | 2017.1.01428.S | 25 | Investigating the role of the magnetic field in high-mass star formaing regime | Even though a consensus on the model at play is still missing in the context of high-mass star formation, it is well established that the magnetic field plays a significant role. Here, we propose to study its impact on 8 massive dense cores (MDCs) of the NGC6334. These MDCs display atypical features with high-mass (~200 Msun) at 0.1 pc scale but only a few low mass proto-stellar cores at ~3000 au scales, while usual efficiency of 30% from cores to stars predicted a few 20 Msun stars in formation in each cores. The model for magnetically regulated core-collapse (e.g. Nakamura & li 2008, Hennebelle et al. 2011) predict such features (low level of fragmentation if a strong magnetic field is present. The magnetic field is also of fist importance to explain the accretion-ejection processes both using the magnetospheric ejection model (Zanni & Ferreira 2013) or using the X-wind model (Shu et al. 1998). In these models the ejection of material forming the outflows occurs along the magnetic field lines. Since all the protostellar objects we propose to study display outflows, our sample is execllent for testing the validity of accretion-ejections models in the high-mass star forming regime. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2020-10-18T23:15:20.000 |
| 2910 | 2022.1.00402.S | 10 | Survey of Chemical Compositions of Star-Forming Cores Embedded in 70 micron-Dark Infrared Dark Clouds | [This is a resubmission of an accepted proposal that has not been yet completed.] Chemical compositions around a protostar are known to be different between high-mass and low-mass star-forming cores. In particular, nitrogen(N)-bearing complex organic molecules (COMs) are more abundant around high-mass protostars than around low-mass protostars. However, the origin of the difference is still controversial. To address this issue, we focus on the chemical composition around protostars in the early phases of high-mass star formation, where protostars are still growing up as low-mass or intermediate-mass ones. We propose to observe nine protostellar sources in the early stages of the high-mass star formation, which are recently found in 70 micron-dark infrared dark clouds, with an angular resolution of 0".12. We will compare the results with those of the other low-mass and more evolved high-mass star-forming cores and assess whether the N-bearing COMs are abundant in the early stages of the high-mass star formation. Based on the results, we will identify the key factors responsible for the different chemical compositions between high-mass and low-mass star-forming cores. | High-mass star formation, Astrochemistry | ISM and star formation | 2024-09-21T12:38:23.000 |
| 2911 | 2022.1.01660.S | 18 | High-resolution Observations of the Tadpole near the Center of Our Galaxy | Intermediate-mass black holes (IMBHs) are an important ingredient that helps create supermassive black holes (SMBHs) at galactic centers, while none of IMBH candidates are accepted as definitive. Recently, several IMBH candidates in the Galactic center (GC) were reported based on the presence of compact molecular clouds with extremely broad velocity widths. "Tadpole" is such a compact cloud discovered at 2.6 arcminutes northwest of the Galactic nucleus, Sgr A*. It is spatially isolated, having a characteristic head-tail structure with a steep velocity gradient in the position-velocity map. Applying the center-of-gravity technique, the kinematics of Tadpole can be reproduced by a Keplerian orbit around a point-like object of 100 thousand solar masses. To confirm this result, we propose ALMA observations of Tadpole in band 7 and 3. High-resolution images will delineate the entity of the orbit stream, diagnose the physical conditions along the stream, and thereby examine the Kaplerian model around a point-like massive object. We expect that Tadpole can provide a promissing candidate for IMBH in the GC environment, which greatly contribute to the understanding of SMBH formation. | Galactic centres/nuclei | Active galaxies | 2024-02-03T18:37:29.000 |
| 2912 | 2016.1.01489.T | 165 | Study of a bow-type structure of Venus atmosphere discovered by the Venus Climate Orbiter, AKATSKI | The Venus climate orbiter, AKATSUKI, entered an elliptical Venusian orbit on December 7, 2015 and discovered a mysterious steady bow-shaped structure extending north-south direction at the longwave infrared (LIR; 10 m) band on December 9, 2015. To understand the following, what happens in the bow-shaped structure;the influence of the bow-shaped structure on the spatial and temporal variation of temperature and minor constituents of the atmosphere of Venus; and how the bow-shaped structure are linked to physical and chemical atmospheric phenomena such as super-rotation, day-to-night circulation, Hadley circulation, and chemical network reactions, we propose to perform the Target of Opportunity (ToO) observation of CO, SO2, SO, and HDO spectral lines with ALMA as soon as AKATSUKI detects the bow-shaped structure again. | Solar system - Planetary atmospheres | Solar system | 2019-05-27T00:00:00.000 |
| 2913 | 2024.1.01132.S | 0 | Resolved Maps of Dense Gas Tracers and CO in LMC Clouds | We request 16.16h of main array time to obtain sensitive (20mK) 12m+7m maps of the emission from Band 3 'dense gas tracers' at sub-pc and 0.1km/s resolution across the 13CO-emitting extent of N206D, and to make 12m+7m+TP observations of CO(1-0) in N206D and N44C. Our targets are two molecular clouds in the Large Magellanic Cloud (LMC). In conjunction with archival data, the proposed observations will provide a set of four LMC molecular clouds that have ALMA maps of low-J CO, 13CO, HCO+, HCN, and CS, and span a range of star formation activity. We will use relative intensities across our set of lines to probe physical conditions across our cloud sample, making use of updated dust and RADEX modeling. We will connect the densest cloud cores and their dynamical state with the large-scale conditions in the galaxy. The proposed maps will build a bridge between highly resolved Galactic work and kpc-scale results from more distant systems, a key to understanding the physics that drives extragalactic scaling laws relating `dense gas' and star formation. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 2914 | 2016.1.01535.S | 16 | Storm in a Teacup: Assessing the impact of AGN feedback on host galaxy gas for a representative low-z quasar | An outstanding issue of galaxy formation models is exactly how quasars impact their host galaxies. We are constraining the prevalence of outflows by combining multiple observational datasets of representative sources. We propose for CO observations of a key object from our sample: the Teacup AGN (z~0.1). We have identified ionised outflows, radio jets and bubbles on kpc scales, suggesting that such phenomena are not strictly limited to extreme sources and clusters. Our proposed ALMA observations will provide crucial information on the molecular gas. We will measure the distribution and velocity structure, comparing to the ionised gas and radio structures, and to the X-ray properties revealed by our extremely recent (2016 April 19) Chandra observation, which reveals a striking extended hot gas structure. We will establish if the jet/bubbles are accelerating/destroying molecular gas and if the outflows are (not) predominantly in an ionised form. These data will provide insight into how quasars couple energy to their host galaxies; importantly, this will be for a representative object from a well defined, systematically selected parent sample. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-05-17T18:38:11.000 |
| 2915 | 2021.2.00094.S | 544 | Searching for complex organic molecules in Orion cold cores | Interstellar complex organic molecules (COMs) are thought to be formed on warm grains (>30 K) and desorpted at high-enough temperature (>100 K). The detection of COMs in starless cores such as L1544 challenges the existing chemical model. Many chemical models were put forward to explain this, but mostly are not well constrained by enough observations. Previous observations were mainly conducted using single-dish telescope and biased to individual famous cold core. We propose to conduct ALMA ACA observations in Band 3 towards 16 candidate prestellar cores in Orion in several transitions of COMs, CH3OH and N2H+. With these data, we will for the first time systematically study the spatial distribution and segregation of COMs in cold cores, and their connections to evolutionary statuses. These informations are essential to constrain the chemical models of COMs. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2024-05-09T03:14:38.000 |
| 2916 | 2017.1.00765.S | 152 | Large-scale infalling envelopes through cold gas tracers | This project is a continuation of our cycle 4 project (2016.1.01541.S) aimed to spatially and spectrally resolve the kinematical structure of the cold infalling gas. Our cycle 4 project (not all data has been delivered) already shows the strength of the cold gas tracers in revealing the infalling stream that CO observations may have missed. The high surface brightness that only ALMA can deliver allows us to study the morphology and kinematics of structures larger than 100 AU up to 10000 AU. The complete picture of the large-scale infalling structure is crucial in determining the survival of volatiles during the disk formation process. Since the skewed line profile predicted from large-scale infalling structure is not always observable toward embedded protostars, measuring the infall rates at large radii may rely on the cold gas tracers. We propose to map 6 additional nearby embedded objects with DCO+, N2H+ and N2D+ in bands 3 and 4. These sources vary in term of luminosity and presence of a disk. The infalling structure may well be connected to the accretion process during the embedded stage. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-07-13T15:24:59.000 |
| 2917 | 2013.1.01046.S | 22 | A combined study of comet 67P/Churyumov-Gerasimenko with Rosetta and ALMA | The Rosetta mission will explore in situ (at a distance of 5 to 200km) comet 67P/Churyumov-Gerasimenko, nominally from July 2014 to December 2015. Comet 67P will reach perihelion on 12 August 2015, during the ALMA Cycle 2 period. On the basis of the ESA adopted activity level of the comet, the main molecular species should be detectable with ALMA during the high activity phase of the comet from April to October 2015. We propose to observe at three different epochs, pre and post-perihelion the key species HCN, CH3OH and CO to derive their total production rates, the gas temperature, their spatial and velocity distribution on the resolution scale (500-1500km) accessible with ALMA. At the same time Rosetta and especially the MIRO and VIRTIS experiments will be observing the same species in situ. As Co-Is of these Rosetta experiments we will have the opportunity to establish a ground truth for the outgassing activity that has been observed over two decades in over 40 comets. We will connect the measurement obtained on the ~1000 km scale from Earth with the activity observed and quantified in situ (from the nucleus surface to beyond 100km) by Rosetta experiments. | Solar system - Comets | Solar system | 2016-06-30T08:23:38.000 |
| 2918 | 2016.1.00909.S | 40 | Captured in Action: the Evolution of Core Mass Function from Prestellar to UCHII Stages in a Linear Filament | The central question of star formation is how mass is converted from dense cores into stars, or, how the core mass function (CMF) evolves to reproduce the stellar initial mass function (IMF). Lack of robust observational constraints on high-mass star-forming CMF has led to diverse theoretical views. With our recent ALMA project as a proof of concept, we propose mosaic imaging of a massive (1500 Msun/pc) linear filament harbouring a sequence of three evolutionary stages in a roll (prestellar->protostellar->UCHII region). The proposed ALMA 1.3mm image will resolve the entire cloud down to 1000 AU with a mass sensitivity of 0.04Msun, allowing a full sampling of individual cores down to 0.2 Msun completeness. We will (1) construct the CMF of the cloud as a whole and the three stages individually, to study CMF evolution; (2) quantify the clustering Q-parameter and study its evolution; (3) quantify the virial state of the cores using N2D+ and other lines, to distinguish theoretical models; (4) search for flow motions with a linear resolution better than the studies of nearby filaments. The results will provide stringent constraints to inform theoretical works. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-12-01T00:00:00.000 |
| 2919 | 2017.1.00051.S | 37 | Constraining jet physics with multi-lambda variability studies of GRS 1915+105 | Two unanswered fundamental questions in accretion physics are (I) how does the accretion process onto compact objects result in powerful, relativistic jets, and (II) how powerful are these jets? In recent years, the study of the correlated multi-wavelength fast variability in black-hole X-ray binaries has led to a number of key results, providing jet speed estimates and tests of theoretical jet models. Here, we propose three 1-hour ALMA observations of GRS 1915+105 in the Band 3, at 1 s resolution, to be taken simultaneously with approved observations in the near-IR (HAWK-I@VLT, 62.5 ms time resolution) and X-rays (XMM, < 1 ms) bands. We will study the accretion-jet connection on all available timescales, estimate the jet speed and determine the size of the jet emitting regions at both mm and IR wavelength, ultimately constraining the structure of the jet, studying how it evolves with flux/accretion rate, and test how well it fits standard models. We will achieve this by performing Fourier analysis of the jet mm emission over a wide range of timescales (1s--30min), and calculating the cross-correlation functions between mm and IR jet emission, and X-ray accretion flow emission. | Black holes | Stars and stellar evolution | 2019-04-16T15:22:05.000 |
| 2920 | 2024.1.00808.S | 0 | Star formation efficiency and quenching patterns in and between galaxies | One of the key open questions in galaxy evolution is what exactly triggers, regulates and quenches star formation. We propose to answer these fundamental questions by mapping CO(2-1) at 1 kpc resolution in a sample of ~500 galaxies who also have optical integral field spectroscopy maps. Compared to previous similar ALMA samples, ours is an order of magnitude larger, and crucially samples the entire mass-SFR parameter space at stellar masses larger than 10^9.5Msun. This big jump is possible through an efficient observing strategy (6 minutes per galaxy rather than ~1 hour in previous similar projects to get the same depth/resolution). With resolved maps of stellar mass, H2, metallicity, SFR, as well as kinematics, we will finally answer the major open questions: (1) what are the respective roles of local and global processes in driving star formation? (2) how are star formation histories regulated? and (3) how do galaxies quench their star formation? The combination of statistics, parameter space coverage, spatial resolution, and availability of matched optical IFU data make this project completely unique, and the only way to deliver fresh insights into these crucial questions. | Surveys of galaxies | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 2921 | 2015.1.00144.S | 102 | Identifying the Host and Physics of an Unknown Extragalactic Emission Line | We have discovered a population of emission lines in a blind spectroscopic survey that have no clear optical counterparts, lie at an unknown redshift, and arise from an unknown atom or molecule. The unknown lines were identified in the ALFALFA HI 21 cm survey, but they are neither 21 cm HI nor 18 cm OH megamasers. We propose an ALMA CO line scan of the brightest emitter. The primary objective is to obtain a redshift, detect mm continuum, and to associate the line with an optical counterpart. The lines are almost certainly non-thermal and represent a new molecular or atomic emission process observable at cosmological distances. One possibility is very high redshift hydrogen recombination line masers (theoretically predicted), but molecular masers associated with extreme starbursts or dusty AGN seem more likely. In order to uncover the nature of these mysterious emission lines, we request 3.7 hours of 12 m time to scan Bands 3 and 4 to obtain a CO redshift. Only ALMA offers the sensitivity and angular resolution needed to solve this mystery. Whatever these lines and their hosts turn out to be, ALMA will open new discovery space and reveal new astrophysical phenomena. | Surveys of galaxies, Galaxy chemistry | Galaxy evolution | 2017-04-06T01:15:20.000 |
| 2922 | 2015.1.00340.S | 22 | Investigating the dynamical interaction at the formation of a multiple star system | Our ALMA Cycle 0,1 observations revealed the complex and dynamical nature of a dense core MC27/L1521F that is at very early stage of the low-mass multiple star formation in Taurus. The features include a high-density starless core with a density of ~2x10^7 cm^-3, a very compact outflow ejected from the very low luminosity Spitzer source with a dynamical time scale of a few hundred years, and the molecular distribution of several cores with the arc-like structure, possibly due to the dynamical gas interaction. The complex structure suggests that the initial condition of star formation is highly dynamical. This proposal aims at investigating the system further to understand a full picture of the protostar formation therein. We obtain the velocity information of the gas that should have created this complex structure to be compared with our theoretical simulation. We will also spatially resolve the very central part of the dense core system containing a very low-luminosity protostar as well as compact dust/gas condensations. The observation of the condensations will confirm the actual evolutionary stage whether the hypothetical first protostellar core is already formed or not. | Low-mass star formation | ISM and star formation | 2018-05-09T19:36:08.000 |
| 2923 | 2015.1.01486.S | 50 | Detailed Physical Properties of the Interstellar Medium of a z=5.2 Dusty Starburst | Studies of the interstellar medium (ISM) at high redshift have progressed tremendously in the past years, but studies of the physical properties based on a suite of fine structure lines (which are critical for studying the earliest cosmic epochs, where CO is faint due to decreasing metallicity) are still in their beginning stages. We here propose an in-depth study of the ISM based on six CNO fine structure lines in a massive starburst galaxy at redshift 5.2 (where all lines fall into a "sweet spot" in the atmosphere), allowing us to push these studies back to the first billion years of cosmic time. This will allow us to measure the fraction of [CII] emission that originated from the neutral vs. ionized medium, the density of both the neutral and ionized medium, the effective temperature in HII regions associated with star-forming clouds, and the O/N abundance ratio. This study will detect fine structure lines up to rest-frame wavelengths of 52 micron in one of the most distant starburst galaxies known, making it an ideal demonstration case for the new ALMA band-10 receivers. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-03-01T02:50:11.000 |
| 2924 | 2017.1.00697.S | 17 | Further ALMA spectroscopy of a Gravitationnaly-lensed z=8.38 galaxy | Determining the properties of early galaxies and confirming their likely role in governing cosmic reionisation represents a major frontier in observational cosmology. In Cycle 3, we spectroscopically-confirmed a z=8.38 lensed galaxy selected in the HST Frontier Fields survey, detecting its dust continuum and [OIII]88mu emission in Band 7. This allowed us to constrain the dust mass and earlier chemical enrichment history for a galaxy that is possibly only 200 Myr old. We now propose to exploit the newly-available Band 5, to compare the strength of [CII] 158mu emission in this unique target as well as to improve our understanding of its dust temperature. Our analysis will be complemented by state-of-the art radiation-hydrodynamical simulations. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-08-30T08:45:19.000 |
| 2925 | 2019.1.01728.S | 130 | Gaia 17bpi: the circumstellar environment of a new FU Ori-type object | FU Orionis-type objects (FUors) are low-mass PMS with outbursts detected at optical and infrared wavelengths. The outbursts are caused by a sudden increase of the mass accretion rate from the circumstellar disk to the star, significantly influencing the final stellar mass. FUors can be Class I or Class II type of objects and, because the eruptions cause significant changes in their environments, it is thought that they play an important role in the transition between Classes. Only a few tens of these objects are known and our target, Gaia 17bpi, is the most recently discovered FUor. This object has not been observed at millimeter wavelengths yet, so we propose the first millimeter wavelength observations of Gaia 17bpi. We request 1.3 mm continuum observations to detect the dust in the disk and the envelope. We also request 12CO, 13CO and C18O observations which will provide information regarding the density of the envelope and can provide a detection of outflows, a common feature FUors. We will also cover a number of more complex molecules to study the chemistry in the circumstellar material. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2021-01-15T17:01:47.000 |
| 2926 | 2023.A.00009.S | 18 | Finding t=0: Tracing the Origins of Rocky Planetesimals with ALMA and JWST | Recent JWST observations serendipitously revealed a large column of hot (~500 K) SiO gas around a low-mass protostar. This temperature is far below the sublimation temperature of silicate grains, so this gas is not simply the result of sublimation of grains in the inner disk. A typical shock origin due to outflowing material is also unlikely given the derived characteristics. Instead, this hot SiO gas is either a remnant of the ~2000 K gas out of which the refractory elements condensed (used to explain the composition of Solar System solids) that has been viscously spreading outward as the disk forms, or it is produced in shocks when material piles up in the inner disk before being accreted onto the star. Shocks in < ~650 K gas are thought to be the formation conditions of chondrules. This latter scenario is likely as observations show that this protostar is at an early stage of an accretion burst. Given the variability on half-year timescales, we propose for ALMA DDT observations to constrain the emitting area of the hot SiO gas to distinguish between these two scenarios and provide unique observations of conditions like those present in the young Solar System. | Disks around low-mass stars | Disks and planet formation | 2024-09-06T13:11:26.000 |
| 2927 | 2017.1.00129.S | 690 | Deep CO(J=1-0) mapping survey of Fornax galaxies with Morita array | We propose a 141-hr deep CO(J=1-0) mapping survey towards 65 Fornax galaxies, aiming for understanding the dominant process for star formation quenching in the Fornax cluster, the largest concentration of galaxies within 20 Mpc in the southern hemisphere. Recently, we found that not only HI but also H2 gas is stripped by the ram pressure from intracluster medium in the Virgo cluster using the phase-space diagram. By comparing the two contrasting clusters, Fornax (less massive and dynamically relaxed) and Virgo (massive and dynamically un-relaxed), we discuss the relationship between the dominant quenching process and the cluster properties. This is a collaboration project with WALLABY, which is the "ASKAP HI All-Sky Survey", a precursor for future SKA HI surveys. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2019-09-06T01:42:36.000 |
| 2928 | 2019.1.01031.S | 118 | Magnetic Fields in CN-Bright Molecular Clouds | We propose pioneering work to measure the magnetic and physical properties of molecular clouds exhibiting bright CN emission. With deep integrations and wider mosaics of a pilot sample in a range of environments, we will (1) Map physical properties in and around these massive, dense clumps via analysis of CO-isotopolog & CN lines plus 3mm continuum; (2) Map polarised 12CO emission from the Goldreich-Kylafis effect, tracing the magnetic field morphology; (3) Precisely define the best locations for future deep CN-Zeeman mapping, once ALMA's spectral circular polarisation reaches sufficient sensitivity. Prior studies show CN+CO are powerful probes of excitation, dynamics, turbulence, abundance, and magnetism in star-forming clouds, but dont uniformly trace the mass distribution. Using radiative transfer analysis and modelling tools we and others have developed, ALMA data will systematically map the physical properties of the clouds, including the critically important but difficult-to-measure magnetic field, adding significantly to our knowledge of this poorly-defined factor in cloud evolution, and forming powerful new synergies with pending SOFIA & APEX observations of these clouds. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-08-21T15:58:37.000 |
| 2929 | 2013.1.00114.S | 4 | Origins of H2CO in protoplanetary disks | Organic ices are the expected major reservoirs of volatile organic material in protoplanetary disks. Their distributions across disks are key to predict the organic composition of planetesimals, and thus the likelihood of organic delivery to terrestrial planets. H2CO is the only detected molecule in disks that may directly probe this reservoir of organic ices. H2CO can form together with CH3OH through CO ice hydrogenation, and this pathway followed by non-thermal desorption is the proposed dominant origin of observed H2CO gas in disks. We propose to constrain the relative importance of ice and gas formation pathways of H2CO in the protoplanetary disk TW Hya, by 1) imaging the H2CO gas distribution with respect to the known CO snowline location at ~30 AU, and 2) determining the H2CO/CH3OH abundance ratio. If H2CO gas originates from H2CO ice, it will only be present in a ring, with the inner edge at the CO snowline and H2CO/CH3OH~1. In contrast if H2CO is mainly a gas-phase product it will present a centrally peaked emission profile and H2CO/CH3OH>>1. The proposed observations will thus directly teach us what the origins of H2CO in disks are. | Disks around low-mass stars | Disks and planet formation | 2015-11-04T14:21:47.000 |
| 2930 | 2016.1.00089.S | 80 | Shut It Down: Probing Molecular Feedback in z=4-5 Dusty, Star-forming Galaxies | One of the most important realizations of the last fiteen years is the vital role that feedback must play in the evolution of galaxies, particularly at the massive end (Mstar > 10^11Msun). Star formation appears to have been efficiently "quenched," but the processes by which quenching occurs are poorly understood. Theoretical models invoke feedback from AGN and/or star formation to disrupt, expel, or heat the gas and prevent further star formation. Recent observations and circumstantial evidence suggests that the bulk of star formation in the earliest quiescent galaxies took place in dusty, star-forming galaxies (DSFGs) at z>4. We propose to test models of feedback and the evolutionary connection between DSFGs and quiescent galaxies by spatially and spectrally resolving massive molecular outflows in 7 z=4.2-5.3 galaxies. Our observations will constrain the outflow geometry and mass loss rates, allowing us to determine whether quenching is due to gas depletion or gas removal. Our targets span a factor of 12 in star formation rate (SFR) and 30 in SFR surface density, giving a large dynamic range to constrain outflow scaling relations and match local work at high-z. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-05-03T16:52:44.000 |
| 2931 | 2022.1.01286.S | 6 | Mapping the Kinematics of the Gravitational Lens PMN J0134-0931 | The gravitational lens PMN J0134-0931 is one of only two known lens systems with six image components. The best-fit lens model need two lensing galaxies, but there are currently no imaging constraining the location and orientation of the lensing galaxies. Molecular absorption of CO(2-1) and HCO+(2-1) have previously been detected in the lens using ALMA, where two of the six components were resolved. Absorption occurs towards both, shifted by 220 km/s. With this proposal we ask for time to observe this system with high enough angular resolution to allow us to measure the kinematics of the absorber across five lens components. This will provide a unique velocity map of the lensing potential and will be a crucial aid in constructing a good model of the lensing potential. We propose to observe the HCO+(2-1) line, which provides the highest opacity, in B3 with an angular resolution of 90mas. We also include the redshifted 183GHz H2O line, which could potentially provide higher opacity and absorption depth than the HCO+ line. | High-z Active Galactic Nuclei (AGN), Damped Lyman Alpha (DLA) systems | Active galaxies | 2024-07-24T21:59:09.000 |
| 2932 | 2015.1.01111.S | 18 | An Efficient Search for [CII]in Normal Star-Forming Galaxies in the Reionization Era | To characterize the sources that are responsible for the reionization of the universe we are faced with two important challenges: I) due to the absorption of Lya photons by the intervening intergalactic medium, spectroscopic confirmations of galaxies at redshifts higher than z>6.5 are extremely rare and II) the stellar masses and ages of z>5.5 galaxies are subject to a few key degeneracies, including the unknown impact of emission lines on the derived masses and the well-known degeneracy between age and dust. We propose to resolve these two challenges with a small sample of three bright galaxies at z~6.8, 800 Myr after the Big Bang, from the CLASH and CANDELS surveys. Our excellent constraints on the redshift probability distribution, due to the observed brightness and blue Spitzer/IRAC colors which pinpoint the sources at z~6.7-6.8, enable a highly efficient search for [CII] during the crucial phase of late reionization (750-900 Myr after the Big Bang). The constraints on the dust content will resolve both degeneracies in our sample and result in accurate age and stellar mass measurements, since the Spitzer/IRAC 4.5m band at redshift z~6.8 is free of emission line contamination. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2017-07-14T15:10:54.000 |
| 2933 | 2012.1.00304.S | 2 | Testing the bow-shock paradigm with the finest molecular jet | In recent years, a number of molecular jets have been identified towards the youngest Class 0 protostars. These jets present morphological and kinematical similarities with the optical jets from more evolved YSOs, and it is expected that the two families are closely related. They likely represent the same phenomenon observed at different stages of protostar evolution, with the younger jets remaining molecular due to their higher density and embedded nature. These molecular jets commonly present regular shapes, in contrast to their optical cousins which are often asymmetric. This is thought to be a consequence of the simpler excitation of the molecular gas compared to the atomic component of the optical jets, and makes molecular jets excellent laboratories for studying jet physics and exploring the possibility that jets drive the more extended and less collimated molecular flows. The main limitation in the study of molecular jets has so far been their weak signal, partly due to the low temperature of the molecular gas compared to the atomic component. ALMA, however, will overcome this limitation and promises to revolutionize the study of molecular jets. ALMA will provide images with the exquisite detail of optical pictures, but with the high velocity resolution needed to test jet physics. Here we propose to observe two positions within the molecular jet from IRAS 04166+2706. This jet appears as a chain of bright peaks whose morphology and velocity pattern show excellent agreement with simulations of pulsating jets. By characterizing in detail the emission from these peaks, we will provide a definitive test to models of internal shocks in a jet, and we will asses whether the lateral ejection of material in these shocks can help shape the rest of the flow. | Outflows, jets and ionized winds | ISM and star formation | 2016-05-25T03:01:20.000 |
| 2934 | 2022.1.01139.S | 421 | [C II]-Scan Survey of the Most UV-Luminous Galaxies at z~7 | The recent success of the ALMA-REBELS survey demonstrates that ALMA is highly efficient in confirming galaxies at z>6.5 through the detection of the [CII] 158um line. Using the publicly available Subaru/HSC source catalog covering ~400 deg^2, we have selected 22 z dropouts (i.e., z~7 galaxy candidates) with exceptional rest-frame UV brightnesses (y<23.8 mag -> Muv<-23 mag). No galaxy sample with comparable UV luminosities had been systematically constructed at z~7 including REBELS (Muv>-23 mag). Taking advantage of this sample, we propose to perform an efficient [CII]-scan observations in the ALMA Band 6 covering z=6.5-7.3. Through the secure detections of [CII] and dust continuum, we will (1) confirm the most UV-luminous galaxies at z~7, (2) probe the bright-end shape of the z~7 UV luminosity function, (3) examine the interplay between AGN and strong starbursts if they coexist, (4) assess the significance of obscured star formation in these UV-luminous galaxies, and (5) explore their environment. Observations with the requested C1-C3 configurations will end by Dec 2022, allowing the timely submission of a follow-up JWST GO-2 proposal in Jan 2023 for confirmed galaxies. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-01-10T20:33:57.000 |
| 2935 | 2011.0.00716.S | 0 | An ideal laboratory to study BH-galaxy co-evolution in the early Universe | We propose to use ALMA bands 6, 7 and 9 to detect the peak dust continuum emission of the most distant submm galaxy (z=4.76) hosting a heavily obscured, Compton-thick QSO. These observations will provide an order of magnitude improvement in the accuracy of the far-infrared luminosity measurement and of all physical quantities related to L_FIR. In addition, these sub-arsec resolution data, obtained in the extended array configuration, will quantify the compactness of the star forming region and possibly show signatures of a major merger. Our science goals will be achieved in ALMA ES in less than 1 hr including calibration in all bands. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2013-11-29T09:14:00.000 |
| 2936 | 2012.1.01069.S | 8 | Mapping the Envelopes of Edge-On Orion Protostars | The observational characterization of the structure, infall, and rotation of protostellar envelopes is a crucial step in understanding the formation of stars and circumstellar disks and how the properties of a protostar may influence the initial conditions of planet formation. We propose to use ALMA to measure envelope rotation in four Orion protostars that are known to be nearly edge-on from HST imaging with the goal of measuring the angular momentum of the infalling envelope. The sources have been observed by the Spitzer, Hubble, and Herschel space telescopes as part of the Herschel Orion Protostar Survey; these data have been used to constrain the source properties by comparing radiative transfer models to the observed spectral energy distributions and images. The objects appear to be at a later stage of protostellar evolution, where the high angular momentum of the infalling material is leading to the formation of the outer circumstellar disk. The sources' edge-on inclinations, relatively low envelope densities, and relative isolation should lead to an unambiguous detection of their envelope rotation and a direct measurement of the angular momentum as a function of radius from the central protostars. From the distribution of angular momentum, we can constrain the initial angular momentum distribution and the subsequent evolution of the angular momentum during infall. Observing these well studied prototypical envelopes will serve as a launching point for future ALMA studies of disk and envelope structure in Orion, the most active star-forming region within 1 kpc of the Sun. | Low-mass star formation | ISM and star formation | 2016-03-09T19:20:23.000 |
| 2937 | 2021.1.00075.S | 7 | CO spectroscopy for an L* Lyman break galaxy at z=8.3118 | We propose Band 3 observations for an L* (Muv=-21 mag) star-forming galaxy (SFG) at z=8.3118, whose [OIII] and dust continuum emission have been detected in previous ALMA observations. Following previous successful CO detections for SFGs at z~6 thanks to the high sensitivity of ALMA, this proposal aims at detecting the CO(7-6), CO(8-7), [CI](2-1) emission and characterizing the properties of molecular gas components in such distant SFGs, which has been poorly investigated in previous studies. We have two science goals: 1) Detecting CO emission lines from normal SFGs beyond redshift 8 for the first time, and 2) Constraining the hydrogen density and the UV radiation field in normal SFGs at this high redshift. Even an extreme case of no CO detection is interesting, because such a result would suggest that invalidities of the empirical relation and/or the theoretical models, which need to be tested for high-z sources. Deep JWST NIRSpec IFU observations will be carried out for our target as a GTO program. By combining this proposed ALMA program and the JWST program with the previous results, we will provide an excellent reference case for future high-z SFG studies. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2022-11-30T23:46:59.000 |
| 2938 | 2017.1.01558.S | 153 | Molecular gas in high-redshift DLAs | Decades of research on damped Lyman-alpha systems (DLAs) have characterized the physical properties -- surface density, chemical enrichment, molecular content -- of the Universe's neutral gas. While these results statistically link DLAs to galaxies, efforts to directly observe this association have been stymied by poor sensitivity and/or spatial resolution. Following on our successful pilot ALMA programs to study CO emission in DLAs at z<1 (6 detections out of 8) and z~2 (2 detections out of 3), we propose to use the Band-3 and Band-4 receivers to carry out a search for redshifted CO(3-2) or CO(4-3) emission from ten metal-strong DLAs at z~2. The proposed observations will allow us to (1) measure the molecular gas and dynamical masses in a sizeable sample of DLAs at z~2, (2) measure the DLA impact parameters, (3) derive the star formation efficiency in the absorbers, by comparing the SFR with the molecular gas mass, and (4) compare the gas dynamics revealed through metal-line absorption and CO emission. This would represent the first, critical step to resolving the physical connections between HI gas in absorption and galaxies at the peak epoch of galaxy formation. | Damped Lyman Alpha (DLA) systems | Cosmology | 2019-08-01T17:46:52.000 |
| 2939 | 2018.1.00689.S | 208 | Search for Inner Disk in Transitional Disks | Transitional disks are protoplanetary disks having an inner cavity and are important targets to study disk evolution and planet formation. Recently, we have discovered an inner subdisk with the radius of 4 AU within the cavity of the disk around DM Tau. This discovery poses a question of the distinction of the pre-transitional (disks with near infrared excess) and transitional disks (those without near infrared excess). These two populations are classified according to SED, but the inner disk structures may have a continuous distribution of various inner disk radii. Based on this discovery, we propose to conduct a small discovery survey to find an inner disk structures of 6 known transitional disk objects by deep, high resolution observations at Band 6. Targets are carefully selected from existing ALMA archival data. The inner disk at several AU from the central star cannot be probed by near infrared excess nor low resolution (~0.15 asec beam) observations. ALMA high resolution observations is the only way to probe directly such structures in a "planet forming" region, whose distance from the central star is similar to that of our Solar System planets from the Sun. | Disks around low-mass stars | Disks and planet formation | 2020-12-09T23:42:29.000 |
| 2940 | 2018.1.00001.S | 33 | The progenitor of the first ellipticals at ultra--high spatial resolution | We propose to carry out [CII] and dust continuum observations in the most luminous pair of interacting dusty starbursts in the early Universe (SGP38326 at z=4.425 with SFR~4500Msun/yr) at 200pc resolution. This is more than 4x times better than in our previous observations of this source. The spectacular continuum and line maps will be used to search for and measure the sizes, velocity dispersion, star-formation rate and morphology of the star-forming regions within the ISM. We will then relate the properties of these star-forming regions to those for the underlying gaseous disk. Combining these observations with previous ones at lower resolution (0.12'') we will investigate the fraction of extended versus compact star-formation and the stability of the disk, a key ingredient models of galaxy formation. These observations will reveal the properties of star formation in the most extreme star-forming source in the early Universe, the likely progenitor of the first ellipticals that were formed and started populating the red sequence of galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2020-11-23T02:51:40.000 |
| 2941 | 2022.1.00716.S | 1080 | Galaxy evolution in the Hydra Cluster through a molecular lens | We propose to observe a stellar mass complete, HI and Halpha selected sample of 108 galaxies in the Hydra Cluster in CO(1-0) in order to study the gaseous evolution of galaxies in clusters, and the capability for galaxies to maintain star formation after their HI gas reservoir has been exhausted. The sample galaxies span the entire range of cluster centric distances from 50 kpc out to the virial radius 1.4 Mpc and three orders of magnitude in stellar mass 10^8.5-11.5 M_Sun. In HI they exhibit a range of morphologies from normal disks to those actively undergoing ram pressure stripping or tidal interactions, or hosting truncated HI disks. Thus, our selected sample traces galaxies at all stages of cluster infall in a statistically unprecedented manner. We will combine our CO observations with ancillary data from MeerKAT (HI), WISE (IR stellar mass and star formation rates) and DECam (optical broadband and Halpha narrowband) in order to build a complete picture of environmentally driven galaxy evolution in the Hydra Cluster. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2024-02-01T19:16:22.000 |
| 2942 | 2017.1.01243.S | 273 | Brown dwarf disks demographics | Circumstellar disks are a signature of star formation by core-collapse and accretion, and the site for planet formation. The disks around young brown dwarfs (BDs) provide an intriguing option to study star and planet formation under extreme conditions. Our partial ALMA survey for BDs disks in the rho-Oph star forming region provided two key insights: BDs disks are less massive and more compact than extrapolated from more massive systems, and the measured amount of solids make it very challenging to support planet formation. With this proposal we aim at measuring the disk masses for all known BDs with infrared excess in three star forming regions: rho-Oph, Lupus and Chamaeleon~I (age 1-3Myr). The data will be compared with the results for disks around stars in the same regions with the goal of constraining the formation channels for BDs and their ability to form planetary systems. Given the evidence for rocky planets around very low mass stars and BDs (e.g. Proxima b and Trappist-1), it is essential to increase the number of measurements of disk masses around young BDs. If low dust masses are typical of BDs disks, then Trappist-1 like systems will have to form on <1Myr timescales. | Disks around low-mass stars | Disks and planet formation | 2019-11-29T21:47:14.000 |
| 2943 | 2018.1.00958.S | 10 | Probing an extreme case of dust settling in a protoplanetary disk | We propose to observe the edge-on protoplanetary disk Oph163131 at high angular resolution to resolve the vertical extension of the disk. The interesting geometry of edge-on disks makes possible to directly observe the vertical structure of both dust and gas of the disk. Combining these observations with the very high-resolution HST optical scattered light images will allows to obtain contraints on the characteristics of dust settling. As opposed to the prototypycal HH 30, Oph163131 shows an extremely flat structure in scattered light. Our cycle 4 observations of Oph163131 suggest that the mm disk is flat, unresolved vertically at 0.2" resolution, very much similar to HH 30 at similar resolution. However, our cycle 5 programme, band 6 at 0.02" resolution, resolved HH 30 vertically. We now propose to perform the same measurement on this much thinner disk. Is the disk of Oph1613131 flatter at mm, as the scattered light images are suggesting? By comparing high resolution millimetric maps of dust and gas in the two disks, we will offer a new perspective on the diversity of protoplanetary disks and add contraints on their vertical structures. | Disks around low-mass stars | Disks and planet formation | 2020-10-19T18:18:03.000 |
| 2944 | 2013.1.00100.S | 10 | Feedback of planets on the protoplanetary disk: gas holes and dust traps in Oph IRS 48 | Planets form in disks of gas and dust around young stars, but little is known about their formation and properties at this early stage. In ALMA Cycle 0 we discovered a major asymmetric dust structure at 60 AU in the transition disk Oph IRS48 indicative of a dust trap which may be the site of planetesimal formation. Our Band 9 12CO 6-5 data also hint at density drops (signatures of one or more embedded planets) inside 60 AU. We propose here higher angular resolution and deeper observations of this fascinating disk, targeting the 13CO and C18O isotopologues of the 3-2 and 6-5 transitions in Band 7 and 9 at 0.2'' to measure the depth of the gap inside 60 AU and quantify any azimuthal asymmetries in the gas in the 60-100 region of the dust trap. We also request 12CO 3-2 observations at 0.12'' to measure the depth of the gas in the 20 AU gap. These measurements will give us direct insight in the properties of potential planets, their formation process and feedback on the disk. Finally, we will measure the wavelength-dependent azimuthal extent of the dust trap to test our proposed mechanism for the dust trap through combined observations of the Band 7, Band 9 and Band 4 continuum. | Disks around low-mass stars | Disks and planet formation | 2016-08-20T12:09:13.000 |
| 2945 | 2024.1.00100.L | 0 | CONDOR: resolving the physical processes that shape disk galaxies at Cosmic Noon | Most of the stellar mass in today's Universe formed in disk galaxies at the peak epoch for star formation (z=1-3, Cosmic Noon). Yet it is still unclear how this dominant population of galaxy disks forms, how the star formation within them is regulated, and how the underlying dark matter is distributed. Resolving these knowledge gaps requires a systematic view of molecular gas at z=1-3. The proposed program, CONDOR, will pioneer this field by resolving the CO emission of 10 massive main-sequence disk galaxies at Cosmic Noon. Combined with the in-hand HST+JWST data and ALMA dust-continuum maps, these resolved observations will provide a comprehensive inventory of the molecular gas, stars, and dark matter in this critical galaxy population. By building on the legacy of ALMA surveys at earlier and later epochs (z~0 and z~5), this unique dataset will unveil how key physical processes like stellar feedback and disk instabilities regulate the evolution of galaxy disks. In this way, CONDOR will also serve as the observational benchmark at Cosmic Noon, providing a legacy dataset for future studies of star formation and galaxy evolution. | Galaxy structure & evolution | Galaxy evolution | 2025-11-15T09:10:04.000 |
| 2946 | 2018.1.00250.S | 437 | What type of stars are the progenitors of water fountain nebulae? | We aim to identify the stellar progenitors of a particular class of post-AGB objects that are characterised by the presence of high-velocity water masers tracing collimated structures. These objects are refered to as water fountain nebulae (wf-nebulae) and their study is important to understand the evolution of intermediate/low mass stars since they are thought to be experiencing their earliest manifestation of asymmetric mass loss. Thus, they have been proposed to be the progenitors of bipolar/multipolar planetary nebulae (PN). Up to date, the fossil circumstellar envelopes (CSE) of wf-nebulae, formed in previous evolutionary phases and holding key information of their mass loss rate history, have not been imaged, nor their physical parameters have been characterised. Consequently, the stellar progenitors of wf-nebulae have not been identified yet. We propose to use ALMA to carry out the first systematic imaging of the molecular emission from the fossil CSE of all known wf-nebulae to characterise their progenitors. From the proposed observations we will obtain physical parameters such as mass loss rate, isotopic ratio, spatial extent, and systemic velocity. | Post-AGB stars | Stars and stellar evolution | 2020-07-13T15:59:57.000 |
| 2947 | 2017.1.00332.S | 108 | Young Quasars in the Early Universe | In the past decade we have experienced a seven fold increase in the number of high redshift quasars (z>6), most of which were discovered by our team. Observations of these objects show that they already host supermassive black holes (SMBHs) less than 1 Gyr after the Big Bang. The formation and growth of these SMBHs on such short timescales remains an important open question. We recently identified a few quasars with very small proximity zones, which is the region of enhanced transmission around the quasar due to its ionizing radiation, indicating quasar lifetimes of only 0.1 Myr. These objects pose a significant challenge to current black hole formation models, which require much longer lifetimes of almost the entire Hubble time. We have identified six new young quasar candidates and propose to obtain precise systemic redshift measurements from [CII] emission lines, which are crucial to obtain accurate lifetime estimates. The confirmation of six additional young quasars would imply that a significant fraction of the known quasar population is significantly younger than previously expected and thus requires new theoretical models explaining the rapid growth of the SMBHs. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2019-05-11T21:12:49.000 |
| 2948 | 2011.0.00236.S | 0 | The Dynamics of Massive Starless Cores | Progress towards resolving a decade-long debate about how massive stars form can be made by determining if massive starless cores exist in a state of near virial equilibrium. These are the initial conditions invoked by the Core Accretion model of McKee & Tan (2003). Alternatively, the Competitive Accretion model of Bonnell et al. (2001) requires sub-virial conditions. We have identified 4 prime examples of massive (~50 Msun) cores from mid-infrared (MIR) extinction mapping (Butler & Tan 2009, 2011) of Infrared Dark Clouds. We have found spectacularly high deuterated fractions of N_2H+ of ~0.5 in these objects (Fontani et al. 2011). Thus N_2D+(3-2) becomes an excellent tracer of the kinematics of these cold, dark cores, where most other molecular tracers are thought to be depleted from the gas phase. ALMA Cycle 0 Compact Configuration Band 6 observations probe this line on scales from 9" down to 2.3", well-matched to the structures we see in MIR extinction. Sharing a 5 hour track between single pointing observations to each of the 4 cores, we have the sensitivity and uv plane coverage needed to measure the kinematics of these structures and thus determine whether or not they are near virial equilibrium. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), High-mass star formation | ISM and star formation | 2013-01-23T20:46:00.000 |
| 2949 | 2019.1.00202.S | 10 | Is the unique ultracool object closest to Earth radio-loud? | WISE J085510.83-071442.5 (W0855) is a unique object: the coldest known brown dwarf (BD) with a temperature of only ~250 K, located just 2.2 pc away. It is extremely faint, even at mid-infrared (MIR) where its spectral energy distribution peaks, making it difficult to investigate if it has companions. However, some cool brown dwarfs (BDs) can have magnetic fields in excess of 1kG and they can emit related radio emission. The angular resolution in the radio regimen can be much higher than in the optical/MIR. Here we propose a pilot project to take advantage of this effect. Out first goal is to investigate the radio properties of W0855 with Band 3 observations. If W0855 is detectable within a reasonable time, we plan to embark (via a future proposal) on a radio-astrometric monitoring campaign to search for companions/planets with much higher accuracy than the best current effort with Spitzer. Should we fail to detect radio emission from W0855, our finding will set an upper limit on the magnetic field of this extremely faint object that is beyond the reach of the modern/near-future high-res spectrographs. | Brown dwarfs | Stars and stellar evolution | 2021-04-04T02:09:25.000 |
| 2950 | 2021.2.00147.S | 45 | Tracing the role of AGB stars in the Galactic Fluorine budget | The cosmic origin of Fluorine (F) is still uncertain. AGB stars are one of the main candidates of F synthesis sites in our Galaxy. They are the only candidates with confirmed observational proof of F production so far, but the question is still open as to what extent AGB stars contribute to the solar-system and Galactic F content. Estimation of the total F budget in AGB stars is needed to quantify their role in the total galactic F budget. In this proposal, we request ALMA-ACA observations of AlF line emission towards three AGB stars which are expected to be efficient in F synthesis from stellar yield models. AlF is one of the two most abundant F-bearing molecule in the outflow around AGB stars. Therefore, measuring overabundance in AlF compared to solar value can potentially quntify the contribution of AGB stars in the F synthesis. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Chemistry | Stars and stellar evolution | 2023-09-20T08:57:17.000 |
| 2951 | 2017.1.00102.S | 254 | The star formation rate distribution of the most luminous quasars: co-eval growth or quenching in action? | We will test the connection between accretion onto supermassive black holes and star formation in the host galaxies of luminous quasars at z~2, the peak epoch of AGN and star formation activity. While this connection is weak or absent in low-to-moderate luminosity AGN, theoretical models predict high star formation rates (SFRs) in the highest luminosity AGNs (log Lbol > 47). Although, these luminous AGN are the sources where AGN feedback, i.e. quenching of star formation, is expected to be most effective, which would suggest reduced SFRs in their host galaxies. Current observations in this luminosity regime have only been sensitive to high SFRs and cannot determine the full star formation rate distribution, which is required to discriminate between these scenarios. ALMA observations of continuum at 850um provide a unique window to probe star formation in these galaxies free of any dilution from the quasars itself. The proposed observations will establish the full star formation rate distribution of luminous quasars and provide important constraints on our theoretical understanding of the co-evolution picture between black holes and galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-06-05T11:48:58.000 |
| 2952 | 2013.1.00527.S | 2 | The carbon abundance in protoplanetary disks | The abundance and budget of carbon in protoplanetary disks determines their gas and solid chemistry, and thus the composition of the forming planets and their atmospheres. The Earth is strongly depleted of solid-phase carbon with respect to the Sun, while the atmospheres of some giant planets are thought to have super-solar carbon to oxygen ratios. These differences must originate in the planet-forming disk stage. The carbon budget in a large volume fraction of the disk can be constrained by determining the gas-phase abundance using far-infrared and millimeter lines of the dominant carriers ([CI], [CII], CO). We propose to place the strictest limit so far on the carbon abundance in several planet-forming disks by obtaining sensitive observations of the atomic carbon [CI]~$1-0$ line with ALMA. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2016-05-28T18:20:54.000 |
| 2953 | 2021.1.00501.S | 36 | Do Truly Quiescent Massive Galaxies Exist at 3<z<4? | The first generation of infrared (IR) surveys revealed an unexpected surprise - a z~2 population of quiescent ultramassive galaxies (UMGs) which completely transformed our understanding of galaxy formation. The recent publications of a small handful of spectroscopically-confirmed UMGs at z>3 hint that the latest generation of deep, wide IR surveys might contain even more transformative discoveries. We propose for Band 7 continuum observations of four spectroscopically-confirmed absorption-line UMGs at 3 < z < 4, selected from the deepest, highest-quality multi-passband catalogs available. These four UMGs show no evidence for rest-frame emission lines from star formation, but the existing optical-IR photometry does not rule out the possibility that one or more sources could be dusty and star-forming rather than truly quiescent in nature. ALMA's sensitivity will allow us to constrain the total amount of (dusty) star formation to <9 M_sun/yr at 3 sigma, ~1.5 dex lower than the main sequence SFR at that redshift. Confirmation of the existence of a sample of bona fide massive quiescent UMGs when the Universe is less than 2 Gyr old would be a high-impact, newsworthy ALMA result. | Galaxy structure & evolution | Galaxy evolution | 2023-10-05T00:21:16.000 |
| 2954 | 2018.1.01070.S | 141 | Measuring the Demographics of Typical Nascent Massive Protoclusters | We propose 0.4" resolution ALMA 3.2mm observations of a sample of 10 massive protoclusters that exist in a specific stage of evolution where outflows are prolific but UCHII regions have not yet formed. This configuration offers a view into protocluster formation prior to the complications of feedback from significant ionizing radiation. The proposed data will enable us to address two key questions: (1) What is the range of evolutionary states of the cluster members? (2) How do the protostellar demographics vary between protoclusters? We have already obtained or have highly-ranked proposals with observations pending for JVLA 5 and 1.3cm and ALMA 1.3mm data for all targets. Adding 3.2mm data to the SEDs is crucial for distinguishing between dust emission and various types of weak free-free emission, allowing us to quantify the properties of each cluster member and accurately measure the protostellar mass reservoirs. With this information, we will measure the CMF and level of mass segregation in this protocluster sample, which is an order of magnitude less luminous and massive than the Young sample in the Motte Cycle 5 Large Program, but with a similarly low luminosity to mass ratio. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2019-11-06T18:02:49.000 |
| 2955 | 2016.1.00794.S | 89 | Millimeter line variability in CW Leo with ALMA Compact Array. | We have performed the first ever successful systematic single dish monitoring of several millimeter lines toward the archetypal carbon star CW Leo. Regular line intensity and line shape variation has been found and maser effects have been suggested. Large velocity dependent phase delays remain unexplained. We propose to monitor the varying millimeter lines with the higher resolution of ACA to confirm the variable behaviors and explore their nature. A series of 1.3 mm continuum and line observations with the ACA in standalone mode (once every two months, but not the standard time constrained mode) are proposed to roughly evenly sample the infrared period of 630 day (in two years). The light curves will also supply key information of variation phase to an accompanying 12-m array monitoring project to test a noval dynamical diagnostics of circumstellar density structures in the same star. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-04-01T22:37:15.000 |
| 2956 | 2011.0.00348.S | 0 | The Physical Environment of Nascent Super Star Clusters v0.3 | ALMA will enable us to probe the molecular environments of nascent ``super star clusters'' for the first time, allowing us to test theories of star formation in this extreme environment. Here we propose observations the dwarf starburst galaxy Henize 2-10. This galaxy is the nearest (~10Mpc) known to host multiple nascent super star clusters. Our primary goal is to map the location of the dense gas in Henize 2-10 with respect to the natal clusters using HCN(1-0) and HCO+(1-0). These observations will spatially resolve the location and kinematics of the densest gas in a system with nascent SSCs for the first time, allowing us to assess the properties of the molecular clouds that give rise to this extreme star formation. The kinematic information will be used to determine the virial masses of these clouds and constrain the star formation efficiency of super star clusters, which is a major outstanding question. In addition, these data will measure the dust-to-gas ratio in these star-forming regions, as well as provide a number of additional molecular diagnostics that will yield a more refined analysis of the physical conditions. This case study is well-suited to early science capabilities and will provide immediate insight into an important mode of star formation. The knowledge gained from this program will also serve to guide future ALMA observations of more distant galaxies. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2014-01-15T20:44:00.000 |
| 2957 | 2015.1.00476.S | 2 | Dense Gas Thermometry of Starburst Galaxies | A characterization of the physical properties of the dense gas within the interstellar medium of starburst galaxies is critical to our understanding of their evolution. Many of the molecular tracers used to characterize the dense gas in star-forming galaxies suffer from a coupled degenerate sensitivity to the kinetic temperature and volume density. A molecular tracer which can decouple individual physical conditions is required. Results from a survey of a sample of active star-forming galaxies has shown that Formaldehyde (H2CO) is a reliable and accurate density probe for extragalactic environments where the kinetic temperature is known. Ammonia (NH3) is a traditional probe of the kinetic temperature in dense gas environments, but its utility requires an assumption of cospatiality between dense gas tracers is required. Using the unique sensitivities to kinetic temperature afforded by the excitation characteristics of several transitions of H2CO, we propose to continue our characterization of the dense gas in galaxies exhibiting starbursts by imaging the gas kinetic temperature in a representative pilot sample of three starburst galaxies: Arp220, NGC253, and NGC4945. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2017-03-03T19:56:34.000 |
| 2958 | 2016.1.00884.S | 172 | Hunting down the cold organic reservoir in protoplanetary disks | We propose to image the spatial distribution of H2CO and its ortho-to-para (o/p) ratio across the bright protoplanetary disk HD163296 to assess its potential as a tracer of the cold organic reservoir. H2CO is the only organic species easily detected in disks that can form on icy grains. Moreover, it plays a key role in the formation of large organic molecules. However, H2CO also can also form in the gas-phase, a mechanism that will dominate in the warm upper layers of the disk. The combination of these two formation pathways prevents us from using H2CO as a direct tracer of the cold reservoir in disks. Fortunately, a simple diagnostic to differentiate between these two contributions is to measure the o/p ratio: H2CO that forms in the gas (or thermally sublimates off warm grains) should have an o/p ratio of 3, while H2CO that non-thermally desorbs from cold grains is expected to have a lower o/p. H2CO o/p measurements thus provide a window onto the cold organic reservoir in protoplanetary disks. | Disks around high-mass stars | Disks and planet formation | 2018-03-22T17:21:22.000 |
| 2959 | 2023.1.00983.S | 0 | Mapping Jet-ISM interactions near X-ray Binaries with Astrochemistry | Relativistic jets launched from accreting black holes carry large amounts of energy and matter into their local environments. Black hole X-ray binaries (BHXBs), the stellar-mass analogues of active galactic nuclei, are ideal targets for studying the interactions between the jet and the ambient ISM in detail, due to their close proximity and the rapid timescale evolution of BHXB jets. Identifying and probing the ISM properties in interaction zones provides insight into highly sought-after jet properties, such as the jet power, composition, duty cycles, and the efficiency of jet feedback. As molecular lines are excellent diagnostics of shock energetics and ISM excitation, we propose ALMA observations of the fields surrounding two recently active BHXBs that show tantilizaing evidence of being located in jet-blown cavities (MAXI J1820+070 and MAXI J1348-630). With these data we will test whether these zones are consistent with being powered by a BHXB jet, searching for the expected cavity morphology and evidence of a fast shock passing through the gas, as well as estimate the energy input into the ISM from these BHXB jets. | Black holes, Transients | Stars and stellar evolution | 2025-02-02T11:54:57.000 |
| 2960 | 2012.1.00064.S | 9 | Exploring the nitrile and oxygen chemistry in Titan's middle atmosphere | Titan's atmosphere is the place of a complex coupled nitrogen-methane chemistry, producing a wealth of hydrocarbons, nitrile and other species, among which oxygen-bearing compounds produced from an external source. The middle atmosphere (50-600 km) experiences strong seasonal modifications; currently an enrichment of several nitriles (HCN, HC3N) is being observed at all latitudes by Cassini. Heavier nitriles such as HC5N, C2H3CN have been also detected, but only in the upper atmosphere (1000 km), from in situ Cassini measurements. Here we want to explore the nitrile and oxygen chemistry of Titan from band 6 measurements at 223/238 GHz in compact configuration. The goals are (i) to search for the HC5N and C2H3CN millimeter lines to determine for the first time their abundances at 150-500 km, strongly constraining photochemical models, (ii) to measure the HCCC15N(27-26) and the HC13CCN(27-26) transitions, to derive for the first time the 14N/15N isotopic ratio in HC3N, thereby exploring the probable existence of a fractionation process similar to one observed on HCN and related to isotope-selective N2 photodissociation, (iii) to search for HCCNC, the isomeric form of HC3N, expected to be present given the recent Herschel discovery of HNC in Titan's atmosphere, and (iv) to search for the yet undetected oxygenated molecule H2CO, to further improve our understanding of the magnitude and nature of the oxygen external source in Titan's atmosphere. The science objectives, none of which can be achieved from Cassini, will bring new insights in the understanding of Titan's complex chemistry. | Solar system - Planetary atmospheres | Solar system | 2016-12-06T12:49:15.000 |
| 2961 | 2016.1.00577.S | 75 | Mapping a binary O-star system in formation. The Milky Way monster GAL333.6-0.2 | We want to map a binary O-star system in formation. Our candidate is in the cluster G333.6-0.2, a well-known ultra-compact HII region at a distance of 3.6 kpc, with an angular diameter of 11" and known to be emitting a Lyman continuum flux equivalent to that of 19 O7V stars. Our previous adaptive optics observations (at 0.1" angular resolution) of the very center of the cluster show a pair of O-type stars (O5V and O4V), separated by 3600 AU and connected by bright continuum emission suggestive of an edge-on disk. Loops and filamentary emission around the possible disk-binary may be structures caused by radiation-driven Rayleigh-Taylor instabilities (rRTI) in the accretion flow and outflow. Our immediate goal is to map the gas velocities at comparable angular resolution and with km/s spectral resolution in radio-recombination and molecular lines to identify rotation, inflow, and outflow and determine whether this system is really a massive binary in formation. | High-mass star formation | ISM and star formation | 2018-08-05T14:17:16.000 |
| 2962 | 2016.1.00911.S | 20 | CO measurement toward the CO-dark dust clouds in the Small Magellanic Cloud | We propose 12CO (J=1-0) observation using ACA toward two CO-dark giant molecular clouds (GMCs, AzTEC/ASTE SMC SW-6 and 13) in the Small Magellanic Cloud (SMC) discovered by the 1.1 mm continuum survey. These objects have never reported detection of CO line emission by previous observations. SW-6 shows the embedded star formation activity, thus the CO formation would not catch up to the beginning of the star formation. In contrast, SW-13 would be the youngest formation phase of GMCs, because this object shows no signs of star formation. These CO-dark GMCs are good examples of CO-dark GMC populations, suggesting that the CO molecule formation is longer than that of the beginning of star formation in the low-metallicity environment like the SMC. Proposed observation uses ACA with the Band 3 receiver, and aims to detect the CO line flux estimated from dust-estimated H2 column density over 10 sigma to quantify the deficiency of CO molecules to 10% level. To cover spatial spread of the objects, we need the 1.5' x 1.5' mosaicking observations. As a result, we require the noise levels of 72 and 84 mK rms for SW-6 and 13 respectively, and the total observing time of 6.5 hours. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2019-10-15T00:00:00.000 |
| 2963 | 2015.1.00601.S | 45 | G351.77--0.51: ridge formation caught in the act | The initial steps of star formation are believed to be tightly linked to the evolution of interstellar filaments. In contrast to lower-mass filaments, mass accretion from large scales may play a key role in the formation of massive ridges. The build up of massive ridges is still poorly understood and only a few examples are known to date. To fill this void, we propose to study a newly discovered filament, G351.77: G351.77 is the youngest and most massive (M=5600 solar masses) ridge in the ATLASGAL survey of the Galactic plane at less than 1 kpc. It has a remarkable large-scale network of sub-filaments and single dish data reveal flows of cold dense gas which converge onto the ridge. With the proposed map, we will settle the following issues: 1) How important is the role of mass replenishment in building up the G351.77 ridge via the sub-filaments? How do large-scale flows impact the final stellar masses? 2) Are we witnessing global collapse of the filament? Given the exceptional proximity of G351.77, the proposed ALMA observations will reach an unprecented spatial resolution (1400 AU) and deliver the most comprehensive view of a massive ridge caught in its youngest phase. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-03-10T15:24:09.000 |
| 2964 | 2015.1.00692.S | 17 | Probing the Host Galaxy of the Most Massive Black Hole at the End of Reionization | We recently discovered an ultra-luminous quasar J0100+2802 at z=6.30, the most luminous known quasar at z>6, powered by a 12 billion M_sun supermassive black hole (SMBH). This discovery strongly challenges theories of SMBH formation. What triggered the extreme BH accretion? Did its host galaxy grow in lockstep with or lag behind the BH? Early PdBI observations show a strong dust continuum and [CII] detection, implying a star formation rate of ~1000 M_sun/yr. We propose to carry out spatially resolved ALMA observations of J0100+2802 to map the dust continuum and [CII] emission of its host galaxy. ALMA observations, combined with HST imaging, will measure the distribution of star formation and dust obscuration in the quasar host galaxy and allow detailed dynamical modeling to estimate the host galaxy mass, probing whether SMBH growth proceeds galaxy assembly. We will search for signatures of galaxy merger and AGN feedback as well as companion [CII] emitters in the highly biased quasar environment. These observations will provide crucial tests to the evolutionary stage of the host galaxy and the triggering mechanism of the most massive SMBHs at the end of cosmic reionization. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-01-09T22:41:11.000 |
| 2965 | 2012.1.00604.S | 16 | Star-formation activity in host galaxies of the most luminous QSOs in the Universe | We propose to observe 14 of the most luminous (L_bol>10^14 L_sun) optically identified quasi-stellar objects (QSOs) in the Universe in order to determine their far-infrared (far-IR) luminosity and constrain the star-formation rate in their host galaxies. The targets have high bolometric luminosities close to the theoretical maximum QSO luminosity (3x10^10 L_sun) based on maximum black hole mass and the Eddington luminosity limit. Four of these fourteen targets have redshifts such that the [CII] 158 micron line, the brightest emission line in the interstellar medium and another important tracer of star formation, falls into ALMA Band 9 or Band 7. We propose to observe the [CII] emission line in these four targets, and the far-IR continuum in all fourteen. By estimating the star-formation rate in the host galaxies of these QSOs, we will place them in context of merger-based galaxy evolution and QSO feedback models, which predict a burst of star-formation activity to occur at the same time that a QSO radiates at maximum luminosity. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-03-19T12:54:14.000 |
| 2966 | 2019.1.00327.S | 10 | Confirming FIR [O III] emission from a candidate z ~ 10 galaxy | We propose ALMA Band 7 observations of a secure candidate for a strongly-lensed z = 10 Lyman break galaxy to confirm a tentative detection of the [O III] 88 micron line we made in our A-graded Cycle 6 program. Given the extremely-high brightness of the [O III] line, which has been demonstrated by our recent ALMA detections of the [O III] line in z = 7-9 LBGs, the proposed study allows us to not only confirm the spectroscopic redshift of the z = 10 candidate LBG, but also characterize metal enrichment for the first time when the age of the Universe was only 480 Myr. The observations will place a stringent limit on metallicity of this LBG even in the case of non-detection of the line. ALMA will therefore provide a very unique opportunity before the JWST era that allows a tantalizing glimpse into the earliest production of heavy elements. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2021-04-01T00:10:38.000 |
| 2967 | 2016.1.00718.S | 17 | The cradles of giant galaxies: the ALMA view of the most powerful QSOs in the Universe | The main goal of this proposal is to shed light on the host galaxies of the most extreme AGN in the Universe. To this end, we selected two WISE/SDSS hyper-luminous (WISSH) QSOs at z~4.5, where winds and feedbacks are well developed. The main products of the proposed observations are: 1) assess whether the QSO host galaxies are in interaction with other nearby galaxies; 2) measure their dynamical mass; 3) given the known SFR, assess the position of the QSOs with respect to the galaxy main-sequence; 4) given the known SMBH masses, study their position in the SMBH mass - galaxy mass diagram; 5) search for any fast winds in the wings of the [CII] emission; 6) measure, or put a limit on the atomic/ionised wind mass loading factor Mdot_OF/SFR, and compare it to that of more normal AGN and star-forming galaxies. The two WISSH QSOs are selected to have: Lbol>~10^48 ergs/s, a robust SFR determination from Herschel, dec<+15 and a redshift fitting well in the ALMA band 7. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-02-04T06:30:46.000 |
| 2968 | 2024.1.01211.S | 0 | Cosmic ray irradiation of a molecular cloud near a high-energy TeV source | Molecular cloud complexes in the vicinity of Galactic high-energy gamma-ray sources are a valuable test-ground for cosmic ray (CR) physics. Our current understanding of CR propagation and interactions on the molecular cloud scale is incomplete. Testing models is currently limited by low-resolution gamma-ray observations, or spectrally-unresolved determinations of CR ionization. In this study, we propose to obtain a complete view of CR propagation in a molecular cloud irradiated by CRs in the vicinity of a TeV gamma-ray source. We will conduct a test of CR propagation, built-up empirically from the magnetic field at measured at gyro-scales. We will self-consistently predict the corresponding CR ionization patterns through the cloud by solving the transport equation, and compare this to chemical signatures of HCO+ and DCO+. Our study will allow a full test of CR microphysics in this system. It will also provide a demonstration of a novel empirical determination of CR propagation parameters which will be generally applicable across the ISM. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-10-25T15:42:28.000 |
| 2969 | 2023.1.01004.S | 0 | Interplay between filament, gravity, B-field, and velocity gradient in a rotating hub-filament system | Hub-Filament systems (HFSs) are the possible transition stage connecting the evolution of filamentary clouds and the formation of massive stars and protoclusters, and hence understanding how HFSs form is a topic of considerable interest. Tthe high-resolution ALMA data reveals that the converging filaments in the massive HFS G33.92+0.11 at sub-pc scale with a spiral pattern, suggesting that the rotational energy becomes dominated in this regime. We propose high resolution (0.6" + 0.24") band 6 polarization observations to probe the B-field within the spiral HFSs from sub-pc to 1600-AU scale. With the obatined data, we will perform a systematic study on the interplay between filament, gravity, B-field, and velocity gradient similar to Wang et al. (2020). This will be further compared to the rotational energy estimated within the rotating system. The observations allow us to investigate how the role of gravity and B-field changes from the spiraling filaments to the protoclusters embedded in the hub, where rotational energy gradually becomes important. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 2970 | 2016.1.00655.S | 24 | Characterizing the Atmosphere and Surface of Triton with ALMA | Triton possesses one of two known micro-bar class atmospheres in our Solar System, with the other belonging to Pluto. Both atmospheres are dominated by N2 in vapor equilibrium with surface ices, with trace amounts of CH4 and CO. Our Cycle 2 ALMA observations of Pluto's atmosphere were quite successful: we detected strong CO(3-2) and HCN(4-3), allowing characterization of the atmosphere in ways that the New Horizons mission could not (neither species was observable by NH). We now propose to obtain comparitive data for Triton, by conducting a sensitive search for CO(3-2) and HCN(4-3) in its atmosphere. From our observations we will i) determine the column abundance of CO to 20%, a factor of 15 better than determined in the near-IR, providing insight into the nature of atmosphere-surface interaction and the maintenance of the atmosphere over time ii) search for HCN, which if detected provides a crucial constraint for understanding Tritons atmospheric photochemistry and microphysics, thermal balance, and volatile escape rates. ALMA is the only facility that can perform the observations necessary to characterize the atmosphere of Triton. | Solar system - Planetary atmospheres, Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2017-12-06T04:32:02.000 |
| 2971 | 2015.1.01135.S | 53 | Pilot CO survey of nearby spiral galaxies with ALMA | We propose a pilot wide-field CO(1-0) mapping survey of nearby spiral galaxies at 200pc resolution with ALMA. The immediate goal of this pilot project is to apply the offset method, which derives the pattern speed and star formation timescale simulataneously by measuring offsets between CO and H-alpha. Using CO maps from existing surveys, we derived these two parameters for five northern spiral galaxies. Furthermore, we found possible correlations between the star formation timescale and other physical parameters such as gas column density and metallicity, which suggest the self gravity of molecular clouds and metal line cooling be a major driver of star formation processes. New CO maps of southern spiral galaxies will enable us to asses if these correlations are real or not, and thus provide important information on mechanisms controlling star formation. In addition, derived pattern speeds will help to understand the nature of the spiral structure in target galaxies. In future cycles, we plan to extend this project to a large survey of ~100 nearby galaxies. ALMA is the only instrument that can perform such a large and wide-field mapping survey with high resolution and sensitivity. | Spiral galaxies, Surveys of galaxies | Local Universe | 2018-03-13T15:04:39.000 |
| 2972 | 2012.1.00945.S | 5 | Imaging of Circumstellar Matter around Protobinary L 1551 IRS 5: From Infalling Envelope to Circumbinary Disk | We propose Band 7 observations of the low-mass protobinary L1551 IRS 5 with ACA + ALMA 12-m array to seamlessly reveal the detailed structure of circumstellar material: i.e., from the infalling envelope with sizescale 13'', or 1800 AU, down to the binary separation of 0.3'', or 42 AU. Accurate measurements of the mass infall rate in the envelope and the centrifugal radius, where the transition from infall to pure rotation is taking place, will allow us to directly derive the ``input rate'' of the angular momentum to the binary system. This is the first step to observationally elucidate the connection between the angular momentum in the envelope and the formation of a binary. We unveil fine structure of transition zone from infall to purely-rotating motion. This will allow us to examine the efficiency of outward transportation of angular momentum in the circumbinary disk. At the same time, we will be able to search for an inner clearing in the circumbinary disk and to determine its size. This is a necessary prelude for observations at even higher angular resolutions to search for accretion streams that penetrate this clearing to feed material onto the circumstellar disks of the individual protostars. | Low-mass star formation | ISM and star formation | 2021-05-15T00:00:00.000 |
| 2973 | 2011.0.00754.S | 0 | The Sombrero galaxy with a very massive black hole at extreme sub-Eddington rate | The Sombrero galaxy is quite unique in the nearest (D=9.3 Mpc) super massive black hole with 10^9 M_sun and an extreme sub-Eddington and jet-suppressed accretion system. We propose point source photometry toward the Sombrero galaxy at 15 frequencies in the band-3, 6, 7 and 9 to obtain continuum spectra to understanding of accretion and outflow phenomena in about 10 Schwarzschild radius or less. This is another way to access the vicinity of the event horizon, as well as a future submm VLBI. We are a unique group that has conducted systematic continuum studies of many nearby low-luminosity AGNs using the Nobeyama Millimeter Array (NMA). The estimated observation time is 0.4~hr (+0.25~hr for switching to band-9) in total. Spectral index, spectral upswing, and spectral peak-out frequency are relevant to the radial profiles of accretion inflow and outflow, and then useful to test several theoretical SED models. Observations quasi-simulteneously at all the 15~frequencies are essential to this study. Hence, we cannot accept to utilize data of line-free channels taken for other individual projects aiming observations of molecular lines, etc. Why we request to cycle-0?: The target source detected with about 100 mJy and little contaminations. The better sensitivities and spatial resolutions of cycle-1 or later are no longer necessary to this target. This unprecedented study provides many first insights and suggestions to future studies for less luminous and more distant samples in the future ALMA. PI and several co-Is are expert for mm interferometry observations and data reductions, and then can contribute the evaluations of ALMA calibrations via this multi-band photometric study. | Black holes, Active Galactic Nuclei (AGN)/Quasars (QSO) | Stars and stellar evolution | 2013-10-30T01:02:00.000 |
| 2974 | 2018.1.00568.S | 7 | Multi-band polarimetric study of a protoplanetary disk to find magnetic-field morphology | We propose to perform polarimetric imaging observation of HD 142527 protoplanetary disk to find the magnetic-field morphology for the first time in a protoplanetary disk. The HD 142527 disk show the polarization with Band 7, which are believed to be purely due to self-scattering of thermal dust emission or due to the combination of the emission from magnetically aligned grains and the self-scattering. Combining the previous study with the requested Band 3 polarization, we can disentangle the mechanisms. If this study is performed, it would be the first study of the magnetic fields as well as the self-scattering in a protoplanetary disk. | Disks around low-mass stars | Disks and planet formation | 2022-09-14T09:22:24.000 |
| 2975 | 2015.1.01093.S | 11 | Unviased Chemical Survey of Protostellar Sources in Perseus | It is well known that low-mass protostellar cores show significant chemical diversity. One distinct case is hot corino chemistry characterized by rich saturated complex organic molecules, while the other distinct case is warm carbon chain chemistry (WCCC) characterized by rich carbon-chain molecules. However, the number of sources definitively classified into them are limited, and the statistics is apparently poor. We here propose to conduct an unbiased survey of chemical composition toward 37 Class 0/I protostars in the Perseus molecular cloud complex. Our recent observations toward these target sources with the single-dish telescopes shows clear chemical diversity, where many intermediate sources are found between the two distinct cases. We are going to confirm this result with ALMA to establish chemical diversity in the 200 AU scale. A relative occurrence of each category (hot corino chemistry, WCCC, or intermediate) as well as preferential association of the sources in each category with a specific part of the cloud complex will give us an important clue to understanding the origin of the chemical diversity in terms of evolutionary history and/or environmental effects. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-08-15T04:03:12.000 |
| 2976 | 2023.1.00268.S | 0 | A First Holistic Disk Volatile Inventory: ALMA and JWST Constraints on Gas and Ice-Phase C, N and O Carriers | The abundance and distribution of C, N, and O-volatiles in disks profoundly influence the outcome of planet formation, including the expected C/N/O ratios of planet cores and atmospheres. In the era of ALMA+JWST, nearby edge-on disks offer a unique opportunity to map out the volatile abundances and the resulting C/N/O ratios in all major disk phases: outer disk gas (ALMA), inner disk gas (JWST line emission spectroscopy), and disk ice (JWST absorption spectroscopy). The JWST ERS Ice Age project have observed one such disk, HH 48 NE, which constitutes the only public data on ice in a disk to date. We propose to combine the existing JWST ice and gas observations towards the HH 48 NE disk with new, complementary spectrally and spatially resolved CO, C2H, HCN and N2H+ (isotopologue) observations to elucidate for the first time the holistic distribution of CO in a disk, including its radial and vertical condensation fronts (snowline and snowsurface), and to constrain the C/N/O gas and solid abundances throughout a disk. | Disks around low-mass stars | Disks and planet formation | 2025-11-19T09:30:50.000 |
| 2977 | 2023.1.00877.S | 0 | Chemical Signatures of a Recently-Confirmed Giant Protoplanet in the HD 169142 Disk | The planet formation process is expected to alter the physical and chemical structure of protoplanetary disks. Since embedded planets will locally heat the disk, this will sublimate volatile-rich ices, or in extreme cases, result in winds, outflows, or shocks that sputter heavy atoms such as Si from dust grains. This will ultimately result in chemical asymmetries detectable in observations of molecular gas. Here, we propose to observe the HD 169142 disk, which hosts a recently-confirmed giant protoplanet HD 169142 b and numerous compelling planet-related chemical signatures, including localized SO emission and the first detection of SiS in disks. We aim to determine origins of these chemical planet-formation tracers and directly constrain the properties of nearby and potentially planet-feeding gas, including the gas-phase C/O ratio. These observations will yield unique constraints on the nature of planet-disk interactions, inform disk chemical models, and benchmark several novel gas tracers of embedded giant planets. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2025-10-04T14:16:18.000 |
| 2978 | 2022.1.01356.S | 266 | A Quest toward the Faint End of the Infrared Luminosity Function at z>4 | Two-mm continuum observations favor the selection of dusty star-forming galaxies (DSFGs) at z>~4, providing one of the best constraints on the obscured cosmic star formation rate densities (CSFRD) when the Universe was only 1-2 Gyrs old. However, so far there is no direct measurement of the faint end (L_IR<10^12 Lsun) of the infrared luminosity function (IRLF) at z>4, leading to one of the largest uncertainties for the obscured CSFRD determination. We propose to conduct a Band-4 continuum survey over 35 massive galaxy cluster fields. This survey will provide the best 2mm source-count function down to 0.01 mJy: ~30x deeper than previous studies. With deep HST, JWST, Spitzer, and Herschel observations and high-quality lens models, we will securely detect strongly magnified sub-L* DSFGs at z>4 and make a robust measurement of the IRLF at z>4. The proposed observations will also 1) measure the dust mass and emissivity of normal DSFGs at z>2 by characterizing the Rayleigh-Jeans tail, 2) constrain the cosmic gas density evolution through the detection of CO emitters, and 3) study the foreground clusters through CO(2-1) line and resolved Sunyaev-Zeldovich effect. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-10-07T05:20:06.000 |
| 2979 | 2019.1.00914.S | 30 | Tracing The Progression of Gas Kinematics from Envelopes to Protostellar Disks | Recent GBT observations revealed intriguing kinetic features in 4 protostellar systems, showing that the star-forming plane (< 100 AU scale) could be completely misaligned with gas rotation at envelope scale (> 10^4 AU). This is opposite to what described by the classical theory of star formation and could indicate significant loss of angular momentum during the formation of protostellar disks. We therefore propose to utilize ALMA's robust sensitivity to probe the detailed kinematics (<0.1 km/s channel width), on scales between the core probed by GBT and the disk/inner envelope probed by previous ALMA observations, of these 4 Class 0/I protostars in Perseus with 1.5" resolution (480 AU) using the widely-used dense gas tracer N2H+ in Band 3. Combining with our in-hand GBT data on the same set of sources but at larger scales (>1' coverage with 9" beam), we aim to follow the progression of gas dynamics in protostellar systems from outer envelopes all the way down to disk-forming regions, which will provide new insight into the spatial distribution and evolution of angular momentum in protostellar systems. | Low-mass star formation | ISM and star formation | 2022-04-30T00:00:00.000 |
| 2980 | 2013.1.01142.S | 4 | Embedded young cluster survey in the Giant Molecular Clouds in the Nearby Spiral Galaxy M33 | We propose 100GHz-band continuum observations at 8pc resolution toward the 75 giant molecular clouds (GMCs) in the nearest spiral galaxy, M33, for the purpose of searching for obscured young clusters. Radio emission at around 100GHz from star-forming galaxies is expected to be strongly dominated by the free-free bremsstrahlung component due to ionizing radiation from massive, short-lived stars. Many studies on external galaxies have widely used the 24micron dust emission as the tracer for obscured star formation. However, the spatial resolution of 24micron data is limited to, for example in case of Spitzer, 6 arcsec. This is not comparable that of the molecular gas images anymore, which can be resolved at sub-arcsec resolution in the ALMA era. With the 100GHz-band continuum data, we aim to obtain a catalog of the obscured star clusters in the GMCs, including size, cluster mass and accurate star formation efficiencies out of a parental GMC. We also check the validity of the star formation rate (SFR) from the the 100GHz-band continuum by comparing with classical SFR measurements,. This will become the new standard method to derive SFR.replacing infrared observations. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2016-11-26T00:13:13.000 |
| 2981 | 2022.1.00727.S | 100 | Cosmic connections: gas and ice in protostellar envelopes | The interplay between interstellar dust, ice and gas in protostellar envelopes prior to the protoplanetary disk (PPD) stage is key to the availability of material that eventually transitions from dense clouds to newly forming planetary systems. This proposal explores the composition and interaction of interstellar gas and ice-coated dust grains at a stage just prior to incorporation into protoplanetary disks (PPDs). We propose to systematically map methanol (CH3OH) ice, which is critical both as an ice tracer and precursor to more complex organic molecules, in a sample of four Class 0/1 protostellar envelopes within the Serpens core on ~200-10 000 AU scales. The creation of the ALMA gas distribution maps will be critical to understanding the chemical evolution of young stellar envelopes at the stage prior to the final assembly of protoplanetary disks, and will be compared to near and mid- IR spectroscopy from the JWST spectra of the same targets. | Astrochemistry | ISM and star formation | 2024-04-05T21:27:57.000 |
| 2982 | 2023.1.00149.S | 0 | IFU Trio of ALMA, MUSE, JWST: Revealing Dynamical Interplay of Inflow/Outflow at z=6 with Strong Lensing Aid | We propose deep [CII] 158um line observations, targeting a strongly lensed galaxy at z=6 discovered in the 100-hr ALMA Lensing Cluster Survey. Among normal star-forming galaxies at zspec>6, it is the brightest lensed source known ([CII] flux=25mJy, H=23.5mag), but intrinsically a faint z=6.07 sub-L* galaxy (Mstar=10^9Msun) due to its high (mu=30-160) magnification. JWST/NIRSpec IFU data show unambiguous ionized gas outflows, while a deep MUSE follow-up reveals a significantly extended (~6") Lya structure around the galaxy, redshifted by ~400km/s. Intriguingly, the current ALMA data also display an extended (~3") and redshifted (~150km/s) [CII] structure potentially associated with Lya. The simple goal of this proposal is to improve the [CII] sensitivity by factors of >2-4 and conclusively map out its 3D distribution relative to Lya. We also request 2.6-hour of JWST F466N imaging to map the Ha distribution which fortunately falls in the NIRcam narrow-band response to understand whether the extended Lya can be ascribed to an inflow or outflow scenario. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2025-06-18T22:22:02.000 |
| 2983 | 2021.1.00911.T | 54 | Direct Sublimation vs. Gas-Phase Synthesis: A Comet ToO Proposal | Comets contain ice, dust and debris left over from the formation of the Solar System. Having remained in a relatively quiescent state ever since, their compositions provide unique insights into the thermal and chemical properties of the protosolar disk and prior interstellar cloud. Detections of complex organic molecules in cometary comae are becoming routine using single-dish mm-wave observations, but the common assumption that these species originate in the cometary ice is largely untested. Recent chemical/hydrodynamic coma models point to gas-phase chemistry as a possible origin for some of these species, while salt dissociation in the coma has recently been suggested for others. We propose to map HC3N, NH2CHO, HCOOH, HNCO (and other coma gases) in a bright target-of-opportunity comet, to reveal whether these species arise directly from the sublimation of cometary ice or whether they are instead synthesized as products of gas-phase chemistry in the coma. In case of only a faint comet in Cycle 8, we will focus on mapping the distributions of more abundant species (H2CO, HNC, CO, CS) to elucidate the behaviour of their (known) distributed sources. | Disks around low-mass stars | Disks and planet formation | 2023-10-05T20:22:25.000 |
| 2984 | 2017.1.01560.S | 102 | Dense Gas associated with the Claimed Intermediate-mass Blackhole Object CO-0.40 | The cloud CO-0.40 at a 40 pc projected distance from the Galactic center is known for its extremely broad emission of 80 km/s width. Since the cloud is not associated with any visible energy sources capable of producing the observed fast turbulence, its nature remains unknown. Recently, an interesting hypothesis has been proposed, which claims that the broad emission comes from gas trailing from a clump gravitationally kicked by an intermediate-mass blackhole (IMBH) of 1e5 Msun. However, the follow-up observation with ALMA has raised several question on the fundamental assumptions made in the IMBH hypothesis, as it failed to detect clear signature of the hypothesized trailing gas. To address this problem, we propose to perform new multi-line imaging observations of the cloud in Bands-6 and -7. The setup of our observations allows to investigate the narrow-line quiescent gas components that have been previously missed. On the basis of the rich information on the cloud's kinematics, physical conditions, and chemistry provided by this observation, we will attempt to re-examine the IMBH hypothesis and to explore an alternative hypothesis in terms of cloud-cloud collision. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-06-22T00:00:00.000 |
| 2985 | 2018.1.00348.S | 84 | Are high-redshift Galaxies hot? Constraining the temperatures of z~5.5 galaxies | We aim to complete our approved Cycle 5 program to measure for the first time the dust temperatures of 4 normal L* galaxies at z~5.5 by continuum observations at rest-frame 110um. The galaxies are observed at 158um and 205um, hence provide today's most unique sample of typical galaxies at z>5. Our proposed 110um observations will allow us to verify possible higher SED temperatures of metal-poor highly star-forming high-z galaxies, which has up to now only been suggested by relations between temperatures and metallicity and specific star-formation rates in local galaxies. Our accurate temperature measurements are crucial to understand the interstellar medium of high-z galaxies by removing the systematic uncertainties of more than a factor 3-5 in total far-infrared (FIR) luminosities and dust masses. We will be able to pinpoint the location of our galaxies on the IRX-beta diagram and improve measurements of the [CII]/FIR luminosity ratio by factors >3, which will shed light on the dust distribution and configuration of molecular clouds in these galaxies. Finally, a better handle on these temperatures enables the interpretation of future ALMA continuum data at high-z (e.g., ALPINE). | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2020-02-27T03:03:39.000 |
| 2986 | 2023.1.01281.S | 0 | Exploring early chemical enrichment with fluorine from WR stars | The origin of fluorine (F) is an unresolved issue in the field of chemical evolution. Various astrophysical sites for F production have been proposed including AGB stars, Type II SNe, and WR stars. Among them, AGB stars are the only site that has been confirmed by observations. One promising way to constrain F yields from other sites than AGB stars is to observe high-z objects. AGB yields of F are significantly small in the early Universe since the AGB phase is a later phase of a low-mass, long-lifetime star. Franco et al. (2021) reported a high F abundance in a z=4.4 star-forming galaxy and argued that WR stars can naturally explain the results. For the further inspection of WR stars' contribution to the F production, we propose to measure F abundance with HF(J=1-0) absorption line targeting a brightest SMG at z=6. The corresponding age of the Universe is only < 0.9Gyr and thus much smaller contaminations from AGB stars and pure contributions from WR stars are expected. Note that existing ALMA and/or upcoming JWST observations towards them enable us to constrain SFH, major uncertainty in the chemical model prediction, through the precise determination of metallicities. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 2987 | 2018.1.01193.T | 93 | Probing The Final Evolution of The Supernova Progenitor | In the last few years, the new paradigm shift has been observed in the field of massive star evolution. Several optical observations of core-collapse supernovae (CC-SNe) have led to an emerging picture that the massive stars are much more dynamic in the last few years than widely accepted previously. However, the existence of the very dense circumstellar matter (CSM), created by intensive mass loss in the final few years, has been inferred mainly from the optical observations, interpretation of which includes highly model-dependent analysis of the radiation transfer effects and a combined effect from various alternative processes. We propose ToO observations of one CC-SN at Bands 3 and 6. The quick ToO at the mm wavelengths within ~10 days after the explosion is a unique and the most powerful diagnostics of the CSM environment in the vicinity of the SN progenitor. This relatively handy project (<3 hours) will bring us new and robust information on the yet-unclarified final evolution of massive stars, and may become a good test case to show the great capability of ALMA in the time domain astronomy. | Evolved stars - Shaping/physical structure, Supernovae (SN) ejecta | Stars and stellar evolution | 2019-12-09T00:04:02.000 |
| 2988 | 2013.1.00404.S | 0 | Mapping the D/H ratio of Complex Organic Molecules in IRAS16293-2422 to probe its dynamics and chemistry | Many complex organic molecules (COMs) have been detected with high abundances towards low-mass protostars. These species are thought to result from active grain surface chemistry during the warm-up phase of the protostellar envelope, and to desorb at high temperatures in the inner regions of protostars. Extremely high deuterium fractionation is a characteristic of low-mass star-forming regions. The investigation of deuterated COMs will allow to further understand the chemical pathways leading to the molecular complexity and how it depends on the evolutionary stage of young Sun-like stars. With ALMA's unique sensitivity and spatial resolution, we propose to observe several COMs and their deuterated counterparts in the two cores of the low-mass protostar IRAS16293. These data will allow to determine the spatial distribution of the COMs deuterium fractionation, to assess the dynamical and physical environment of the source and to constrain the COMs formation pathways. For that, we will compare the derived abundances of COMs and deuterated isotopologues as a function of radius with gas-grain chemistry model predictions coupled with realistic dynamical models of each core. | Low-mass star formation | ISM and star formation | 2017-10-21T00:00:00.000 |
| 2989 | 2017.1.01199.S | 24 | Probing the Nitrile Reservoir of the Comet Forming Zone in a Solar Nebula Analog | Observations of comets and meteorites show that the planet and comet forming midplane of the young Solar Nebula had a rich organic volatile composition. In particular, the Rosetta mission has recently shown that comets are abundant in nitrile species such as HCN and CH3CN. Simultaneously, ALMA has revealed that protoplanetary disks have abundances of the complex nitriles CH3CN and HC3N that are be consistent with cometary values, suggesting that the chemistry of the Solar Nebula was may not be unique. In a Cycle 4 program, we recently obtained observations of CH3CN emission toward the Solar Nebula analog TW Hya. The emission is considerably brighter than that of CH3CN in other disks, but provides few constraints on the midplane abundance, with high upper state energies that likely trace the warm upper layers of the disk. Probing midplane abundances requires peering deeper into the disk with observations of lower energy transitions, and thus pushing to lower frequencies. We therefore propose to observe low energy transitions of CH3CN and HC3N in Band 3, allowing us to measure the abundances of these species in the comet forming midplane. | Disks around low-mass stars | Disks and planet formation | 2019-10-15T23:20:29.000 |
| 2990 | 2022.1.01801.S | 0 | Can CI trace CO-dark molecular gas at kpc scale? | Neutral atomic carbon (CI) and CO are important ISM tracers. The CI/CO line ratio is sensitive to gas temperature, density, metallicity, radiation field and molecular cloud evolutionary stage. Limited observations and theoretical predictions have led to fuzzy understanding of CI abundance at low metallicity and across galactic environments. Basically, we desperately lack CI mapping of objects intermediate between LMC/SMC-like irregular dwarfs and massive spirals like NGC3627 to be able to precisely link the CI/CO radio to ISM properties and different galactic environments. Here we propose deep ACA CI mapping in the low-metallicity barred spiral NGC5068 at GMC scales. The galaxy has well mapped CO(2-1), HI, H-alpha, UV and HII region metallicity maps. The proposed mapping covers a variety of environments: a HI-bright arm, bar ends, giant HII regions, varying UV radiation field, and metallicity between 0.2 and 0.5 solar, most of which cannot be studied in LMC/SMC or massive spirals alone. This study will critically advance our understanding of CI/CO excitation and help benchmark CI and CO tracing the cold gas in early universe like environments. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2024-10-26T20:47:17.000 |
| 2991 | 2017.1.00017.S | 18 | Observing the ashes of the i process in V4334 Sgr | In many instances of stellar evolution, especially at very low metallicity, H-combustion events (triggering the i process) are encountered. Exactly how these stars deviate from normal evolution is not clear. This is however important for modeling the evolution of the first generation of stars in the Universe. A direct comparison of models with observations can only be done in the case of Sakurai's object (V4334 Sgr), a post-AGB star which recently experienced a very late thermal pulse. The mixing of proton rich material into the 12C-rich He-shell induced exotic neutron-capture nucleosynthesis. The high efficiency of this process, together with the immediate ejection of the burning products, offers a unique possibility to study the i process. This can be done by studying the carbon isotopic composition through observations of isotopologues of carbon-bearing molecules. In particular we propose to derive the ratio 12C:13C:14C, which (apart from 4He, 16O, and 14N) are the three most abundant isotopes in the ejecta. The proposed observations will provide strong constraints on the i process. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2019-10-17T19:13:57.000 |
| 2992 | 2016.1.00387.S | 120 | Spectral Scan on A Compact Obscured Nucleus | We propose a 190 GHz spectral scan through bands 3, 4, 6, and 7 at ~0.2" toward the compact obscured nucleus of the luminous infrared galaxy NGC 4418. This extremely dust-enshrouded 1e11 Lsun nucleus must be rapidly evolving either as a Compton-thick AGN with a high-Eddington ratio or a very young compact starburst. Its true nature has eluded investigations with all sorts of telescopes over three decades. We here employ ALMA for an almost confusion-limited scan of about 1000 lines from within 20 pc of the galactic center to strongly constrain the physical conditions and chemical composition of the nuclear interstellar medium. We will thereby address the nature of the hidden luminosity source. In particular, lines from IR-pumped vibrationally excited molecules will be searched and used to reveal the nuclear radiation field and temperature structure. We already have 50 GHz of data and request for the rest. In addition for our own analysis of NGC 4418, our data will also serve as a reference for any attempt to identify hidden nuclear activities through mm-submm spectroscopy and for astrochemistry in general. [18 of 23 SGs are in Cyc. 3 filler. No need to repeat if observed.] | Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-03-29T15:22:10.000 |
| 2993 | 2019.2.00166.S | 26 | Velocity and density power spectra along the Musca filament: Hints to the origin of the star formation properties | There is a growing evidence of the key role of molecular filaments in the star formation process. Important questions are to understand the physical processes 1) leading to the fragmentation of these filaments into bound cores and 2) governing the properties of these cores (e.g., mass distribution and angular momentum). Recent theoretical studies suggest that the fragmentation of a self-gravitating filament characterized by a velocity power spectrum with a slope of -5/3 (i.e., a Kolmogorov spectrum) may be at the origin of the observed mass distribution of cores and their angular momentum. Here we propose ACA band 3 and 6 observations to trace the molecular emission of C18O(1-0) and (2-1) along Musca, a low-mass filament at the verge of gravitational fragmentation, to derive for the first time its velocity power spectrum and test the theoretical models. Thanks to the two C18O transitions we will also have the required data to constrain the density and temperature of Musca and derive an accurate estimate of the line-of-sight depth to constrain the 3D structure of the Musca cloud: cylindrical filament or sheet-like. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-04-16T07:12:53.000 |
| 2994 | 2012.1.00437.S | 1 | Massive CO-rich Comet Clouds Around Youthful Main Sequence Stars | Dusty debris disks are known around hundreds of main sequence stars with ages of 30 Myr or greater but, among these, associated gas (carbon monoxide) has been detected with radio telescopes in the vicinity of only two A-type stars. Given the short lifetime (~500 yr) of a CO molecule in stellar and interstellar radiation fields, even two such detections are difficult to explain. We propose a search for CO in a carefully selected sample of 10 dusty debris disks. Discovery with ALMA of additional examples of disks that contain CO should confirm or deny the plausible hypothesis that the CO is generated via very frequent collisions of comets rich in CO and CO2 in regions analogous to the Sun's Kuiper Belt but containing a total cometary mass equal to hundreds of Earth masses. | Debris disks | Disks and planet formation | 2015-07-22T23:59:59.000 |
| 2995 | 2019.1.00063.S | 30 | The kilo-au environments of T Tauri stars | We propose to use the ACA to image the molecular environments of three well-known T Tauri stars at intermediate size of a few thousand au between that of protostellar cores and protoplanetary disks. The resolution of ~5 arcseconds lies in an observational blind spot, generally below the resolution of singledish telescopes and largely filtered out by interferometry. There are indications from scattered light images, CO maps, and theoretical predictions on the interaction between young stars and their surrounding clouds that infall onto disks can continue well into the Class II phase. These ACA mosaics will reveal the structure and kinematics of the kilo-au environment with much greater clarity than before. | Disks around low-mass stars | Disks and planet formation | 2021-05-14T05:51:35.000 |
| 2996 | 2019.1.00523.S | 5 | Accretion and Feedback of a Very Massive Protostar | Forming massive stars become so luminous that their ionizing feedback may stop the accretion and limit their further growth. In order to investigate the accretion and feedback processes in the formation of very massive stars, we propose ALMA Band 7 highest resolution observations of continuum and hydrogen recombination lines toward the massive young stellar object G45.47+0.05. Previous Band 6 observations reveal an hourglass-shape bipolar photoevaporative outflow in this source, which may also drive a strong jet with nonthermal emissions embedded inside the ionized outflow, suggesting on-going accretion. Here we aim to probe the dust component surrounding the ionized outflow and inner ionized disk to investigate the impact of the photoionization feedback on the accretion disk and surrounding material. We also aim to use hydrogen recombination lines to study the kinematics of the ionized gas, especially disk rotation and the outflow motions to test the disk accretion scenario and evaluate the strength of feedback. These observations will put strong constraints on how feedback and accretion processes interact with each other around a forming star of at least 40 solar masses. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2023-01-17T20:52:39.000 |
| 2997 | 2017.1.01705.S | 0 | The heating mechanism for the cool, far-IR emiting dust in AGN | In order to understand the links between AGN and galaxy evolution it is important to determine accurate star formation rates (SFR) for the AGN host galaxies. Far-IR luminosities are often considered to provide a ``clean'' diagnostic of the SFR. However, recent work has suggested that emission from cool dust in the kpc-scale narrow-line region (NLR) can make a major contrinution, and perhaps dominate, the far-IR cotinuum. We propose to use the unique capabilities of ALMA to make a decisive test of the idea that the NLR cool dust emission is important at far-IR wacvelengths, by using Band 9 (675 GHz) observations to image two nearby radio AGN. If the cool dust emission proves to be concentrated in cone-line structures aligned along the axes of the large-scale radio structures (i.e. following the structure of the NLR), this will provide clear evidence for a major contribution from the NLR at far-IR wavelengths. On the other hand, if the far-IR radiation is predominantly emitted by regions of obscured star formation in the kpc-scale dust lanes perpendicular to the radio axes, this will strengthen the idea that the far-IR provides a ``clean'' SFR diagnostic. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-11-22T16:26:32.000 |
| 2998 | 2017.1.01471.S | 21 | Rotation Curves of Star-Forming Galaxies at z>4 | Rotation curves (RCs) are a prime tool to study the distribution of mass (luminous and dark) in galaxies, providing strong constraints to galaxy formation models. High-quality RCs have been derived for hundreds of galaxies at z=0 and for several objects at z=1-2, but no detailed study exists at higher z. We aim to derive the first high-quality RCs for objects at z>4, when galaxy properties are expected to be radically different from z=0. We request [CII] observations at 0.1" resolution for three objects at z=4-7 that were previously observed with ALMA at lower resolutions. The archival data show that the [CII] emission forms a rotating disk, but they do not allow a detailed kinematical study. The higher spatial resolution will allow us to (1) map the [CII] distribution and kinematics at sub-kpc scales, (2) derive RCs and constrain the properties of dark matter halos, (3) estimate the degree of turbulence in primordial disks, (4) investigate possible gas inflows/outflows. This pilot study will assess the potential of high-resolution follow-up observations with ALMA, which is timely given the increasing number of low-resolution [CII] surveys at high z. | Galaxy structure & evolution | Galaxy evolution | 2019-12-10T14:29:17.000 |
| 2999 | 2021.1.01431.V | 0 | Revealing the magnetic field in the jet acceleration zone of the Crazy Diamond | 3C 454.3, the brightest gamma-ray source ever recorded in the sky, now can be imaged for the first time with a superb resolution down to ~1000 Schwarzschild radii, offering a direct view of a region where a powerful relativistic jet blasts away from the central engine. The study of the recollimation profile of the plasma flow and the brightness temperature, will give an answer in the long-standing problems of the nature of the VLBI core (opacity surface/recollimation shock/jet bending), and the energy balance between magnetic and particle density. The polarimetric observations will reveal the magnetic field topology across and along the jet, in regions where jets are accelerated and collimated. The 3D reconstruction of the magnetic fields will prove or not the existence of a magnetic helix embedded in a curved jet, as implied from the high-energy emission pattern. The results will be compared with GRMHD jet formation models, contributing in better understanding the jet launching from black holes. The inclusion of ALMA is crucial, as it improves the North-South resolution by a factor of 2 (beam of 56x19 microarcsec), which is essential for a deep polarization imaging of 3C 454.3. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-07-31T09:26:04.000 |
| 3000 | 2015.1.00845.S | 66 | An advanced method to detect complex molecules in protoplanetary disks | One of the most important questions of astrochemistry is how, when and whether complex organic molecules (i.e that contain more than 6 atoms) and potentially prebiotic molecules are formed and could this have a bearing on the origin of life on Earth? In that context, we are focussing on the two following key molecules: methanol (CH3OH) and formic acid (HCOOH), that are precursors of larger species, including potentially prebiotic molecules. Those key molecules have been detected toward star-forming regions and comets, but not in protoplanetary disks. Nevertheless, these species are likely expected to be present in those environments. In the proposed observations, we intend to detect both methanol and formic acid by using an advanced method where we will stack multiple transitions of methanol and formic acid by summing up their intensities, respectively. | Astrochemistry | ISM and star formation | 2017-08-16T16:41:18.000 |
| 3001 | 2016.1.00207.S | 30 | Companion(s) in the disk of the nearby AGB star L2 Puppis | The nearby AGB star L2 Pup is likely at the early stages of the formation of a bipolar planetary nebula. Our ALMA C3 observatinos provided an outstanding view of the rotation profile of its molecular disk, and evidenced complex dynamics in the polar wind. They tell us that the central object is a low mass star (~0.7 Msun). Velocity asymmetries are present in the molecular disk, and our hypothesis is that they are caused by one or more low-mass companions. We see clues of their presence in our adaptive optics polarimetric images at visible wavelengths that have a comparable angular resolution (0.020") to the ALMA cubes. We propose to search for low-mass companions through their gravitational influence on the molecular disk (SG1). We will trace the evolution of the inhomogeneities of the rotation profile of the molecular disk, 21 months after our C3 data. We will check if they are persistent, if they rotate with Keplerian velocity, and if their position matches the plumes detected in the visible. Our SG2 is to measure the parallax of L2 Pup (essential to secure the mass). This is very difficult in the visible due to the changing morphology of the nebula, but feasible with ALMA. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-09-09T19:23:38.000 |
| 3002 | 2012.1.00611.S | 21 | Dense, Warm Molecular Gas and Star Formation in CO Luminous QSO Hosts | Our recent CO(1-0) survey of z < 0.3 UV-excess Palomar Green (PG) QSO hosts has shown that at least 38% reside in CO-rich host galaxies. We propose here to make use of the sensitivity and high angular resolution possible with Band 7 of Cycle 1 ALMA to observe CO(3-2) emission from four PG QSO hosts previously detected in CO(1-0). This `complete sample' has been selected to be nearby (z < 0.2), have a declination < 15 degrees, and to have CO(3-2) redshifted to a frequency with good atmospheric transmission. The CO(3-2) line is an ideal diagnostic line for star formation; it traces the dense, warm molecular gas component associated with high mass star-forming regions in galaxies. With these data, we will be able to (a) measure the compactness of the CO(3-2) emission and its distribution relative to stellar light, to (b) determine if the radio emission from these QSOs is co-spatial with the CO(3-2), and thus associated with star formation, and to (c) make use of the CO(3-2)-to-infrared luminosity relation of starburst galaxies to estimate the host star formation rates. This survey builds upon multi-wavelength observations of this population of extreme QSO hosts done by us over the last two decades, and it turns the focus of our work directly to diagnosing their starburst properties. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-09-14T20:32:30.000 |
| 3003 | 2021.1.00143.S | 36 | Spatially Resolving [CII] in the Brightest 0.5-L* Galaxy at z~6 | We propose to scan the [CII] 158um emission line and dust continuum of the recently discovered, brightest known z~6.3 Lyman break galaxy, which has been highly gravitationally lensed into a spatially resolved arc with bright clumps. Intrinsically, this highly magnified (mu=17) galaxy has a low SFR (~6 M_s/yr) and is fainter than the characteristic luminosity (0.5L*), which allows ALMA to uniquely probe the low-SFR end of the [CII]-SFR relation and spatially resolve [CII] at the same time. Through the full redshift probability scan observations, this observation will unambiguously determine [CII] luminosity of a low-mass/sub-L* galaxy, and will allow us to achieve following goals: (1) spectroscopic redshift confirmation of z~6.3 galaxy and exploring the low-SFR end of [CII]-SFR relation (2) gas morpho-kinematic study of a reionization-era galaxy seen by the extended arc (3) detailed study of dust-star geometry and resolved dust-attenuation properties. Such observations for low-mass/sub-L* galaxies are only possible with strongly lensed sources. With the high-magnification and extended arc, our target is an ideal and unique opportunity to study a low-mass galaxy in great detail. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2023-10-26T15:31:52.000 |
| 3004 | 2016.A.00015.S | 36 | Gamma-ray Burst Physics with ALMA: The unusual afterglow of GRB 161219B | We have detected the afterglow of GRB~161219B with ALMA using our recently concluded project 2016.1.00819.T. The millimeter afterglow is bright, and our suite of follow-up multi-wavelength observations suggest a unique, and unexpectedly complex emission process. We are submitting this DDT proposal to request two additional follow-up observations of the afterglow on a timescale of 4-10 weeks since discovery. | Transients | Stars and stellar evolution | 2017-07-24T19:22:36.000 |
| 3005 | 2018.1.00862.S | 207 | Perfect Twins? Excited Molecular Gas Clumps Symmetric to Sgr A* | At positions (l,b)=(-5.4deg, +0.4deg) and (+5.4deg, -0.4deg), there are two molecular cloud complexes, Bania 1 and G5, that are exactly point-symmetric to the supermassive black hole Sgr A* in the Galactic Center. The clouds are a projected 740pc away from Sgr A* and have very similar masses of ~10e5 Mo. At these distances, most of the molecular gas is cold and quiet disk gas. Bania 1/G5, however, are both very hot (~150K), highly excited, and exhibit large line widths of tens of km/s. These properties are similar to gas in the Central Molecular Zone rather than the disk. The exact point-symmetry to Sgr A* and their very similar properties suggest a common origin. Options are: a) the inner Milky Way potential is double-barred and the clouds sit in the outer bar x2 orbits, or b) outflows/jets from Sgr A* have created and shocked the gas at l=+-5deg. We propose to use the ACA to test scenarios via the structural properties, shocks, excitation, and temperatures of Bania 1 and G5 down to 6" (0.25pc) via CO(2-1) isotopologues, SiO, HC3N, and H2CO transitions, and the H30alpha ionization radio recombination line. | Outflows, jets and ionized winds, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-07-08T23:08:07.000 |
| 3006 | 2017.1.00118.S | 33 | Properties of Massive Stars and HII Regions in the First Billion Years | Using ALMA, we have recently discovered that ~15% of redshift 6 quasars show evidence for actively star-forming companion galaxies with SFR~80-800 Msun/yr within 8-60kpc, suggesting that the quasars form and evolve in overdense environments within the first billion years of cosmic time. We here aim to probe the conditions for star formation in two of these environments (one this cycle, one in cycle-6) by studying the physical properties of the HII regions (e.g., effective temperatures, radiation field intensities, metallicity and evolutionary stage) around massive, recently formed stars in the quasar host galaxies and star-forming companions through the [OIII] 88um line and dust continuum. Recent studies tentatively show that this line may be enhanced at low metallicity and in young galaxies in the very early universe due to stronger and perhaps harder radiation fields, with up to an order of magnitude higher luminosities than measured even in the most commonly targeted [CII] 158um line. The proposed study will put these preliminary results on a firmer footing by extending them to a larger range in star formation rates, masses and environments, including AGN host galaxies at z>6. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2020-02-22T00:00:00.000 |
| 3007 | 2019.1.00502.S | 15 | Searching for high-mass pre-stellar cores in an exceptional nursery | The W43-MM1 ridge that is an extreme cloud in terms of concentration and star formation activity, is a case-study to confront models of high-mass star formation. An ALMA Cycle 2 1 mm mosaic of W43-MM1 revealed a rich protocluster of 131 cores, among which 18 able to form a high-mass star. The study of SiO shocks tracing protostellar outflows and chemical complexity associated with protostellar heating led to the preliminary identification of 11 high-mass protostars, 1 high-mass pre-stellar core candidate and six core whose nature remains undefined. The outflow study is however blurred by the richness of the protocluster; all identified outflows are notably confused by neighbor outflows. Hot core investigation is itself limited by the line strength of heated gas strongly diluted within the massive cold envelope of cores. We propose to disentangle and definitively determine the evolutionary status of 18 high-mass cores identified in Cycle 2. We will then give constraints on the most plausible scenario of high-mass star formation using the complete sample of high-mass cores in W43-MM1, their measured turbulence levels and gas mass inflows. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2022-10-19T22:39:26.000 |
| 3008 | 2016.1.01001.S | 230 | What is the Origin and Subsequent Evolution of Starbursts at z~2? | We propose to obtain resolved CO maps (0.2" resolution, corresponding to ~1.5 kpc at the redshift of our sample) for 16 extremely luminous dusty star forming galaxies (log(L_IR/L_sun)) > 12.5) at the peak epoch of star formation activity (2 | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2018-11-03T04:31:47.000 |
| 3009 | 2017.1.00368.S | 42 | How can cold molecular gas survive near R136 in 30 Doradus? | In the current paradigm of star formation, the densest regions of giant molecular clouds collapse into clumps, which eventually form Young Massive Clusters (YMC) which removes the molecular gas in its surrounding, decimating further star formation. Surprisingly there is cold molecular material very near (<10pc in projection) R136, the nearest YMC, located in the 30 Doradus star forming region in the metal-poor (0.5 Zo) LMC. According to most theoretical predictions, the photo-ionising luminosity of the cluster is sufficient to evacuate any dense molecular gas surrounding the cluster within ~1 Myr. Our aim is to determine the origin of this weak cold CO gas. Are these molecular clumps (gas mass ~ 103 Mo) driven by the outwards wind momentum or VERY DENSE clumps that have survived photo-dissociation? We propose to obtain high spatial resolution 1 (0.25 pc at 30dor distance of 50 kpc) ALMA maps to resolve the spatial structure of the cold gas. By mapping in CO(3-2) and the high density tracers 13CO(3-2), CS(7-6), HCO+ and HCN we can determine the velocity distribution and density of the molecular gas near R136 and study the molecular cloud properties in such an extreme environment. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2020-03-14T00:00:00.000 |
| 3010 | 2018.1.01321.S | 197 | Physics at High Angular Resolution in Nearby Galaxies: The Local Galaxy Inventory | We propose to utilize the ACA (7m+TP) to map the full star forming disks of three nearby, large-on-the-sky galaxies (NGC 300, NGC 253, Circinus) in CO(2-1) in order to assess their molecular ISM at scales of individual molecular clouds (50-100 pc). These data will provide key insight into the interplay between galactic environment and cloud-scale molecular gas. These galaxies harbor a range of physical environments, from AGN to nuclear starburst to flocculent spiral, and thus provide a crucial link between the Local Group (where high resolution permits study of sub-cloud scale physics) and the broader galaxy population (which includes a wider range of environments). With these data we will measure GMC properties and scaling relations, cloud lifetimes, and star formation efficiency as a function of the diverse environments found in these galaxies. The resolution, sensitivity, and spatial coverage match those of our ongoing Large Program to map the disks of more distant targets with the 12m array, and so these additional galaxies will both fold into and inform the larger sample while providing context for ongoing and future zoom-in studies. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2020-01-04T16:32:57.000 |
| 3011 | 2013.1.00248.S | 19 | Resolving the Initial Conditions of Massive Star Formation - A Tale of Two Cores | We detected two massive, apparently-starless cores with ALMA in Cycle 0. Now we wish to resolve them with 10 times better angular resolution, the finest available in Cycle 2, to make definitive tests of massive star formation theories. One core C1-South appears very rounded, centrally-concentrated and monolithic. We will be able to resolve its diameter with more than 30 resolution elements in both 1.3mm continuum and molecular lines, principally N2D+(3-2). If it continues to remain smooth and coherent, we will be able to derive its radial density, temperature and dust emissivity profiles. We will measure the radial profile of its velocity dispersion, and thus turbulent pressure, to test models of hydrostatic equilibrium. The other core, C1-North, appears more fragmented and we will be able to resolve this substructure, both spatially and kinematically. Having these two distinct cores close together within the same field of view provides a convenient laboratory for testing massive star formation theories. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-06-03T20:22:32.000 |
| 3012 | 2016.1.00712.S | 15 | The bright, inclined disk of IM Lup: an ideal laboratory for studying dust-scattering-induced millimeter polarization | New studies have shown that millimeter-wave polarization from protoplanetary disks can be produced from scattering by dust (Kataoka et al. 2015, 2016; Yang et al. 2016a,b). However, recent observations of disk polarization -- most notably toward HL Tau (Stephens et al. 2014) and NGC 1333-IRAS 4A1 (Cox et al. 2015) -- may be contaminated by polarization from dust grain alignment. To be confident that we are observing polarization caused by dust scattering and not by emission from magnetically aligned grains, we propose Band 7 polarization observations toward the large, bright, inclined, and optically thin disk of IM Lup, a weakly accreting T Tauri star that is an ideal laboratory for testing dust-scattering theories. | Disks around low-mass stars | Disks and planet formation | 2018-05-23T20:07:02.000 |
| 3013 | 2016.1.01296.S | 12 | Resolving super star clusters in nearby dwarf galaxy NGC 6822 at GMC dense clump scales | In the Milky Way, most stars, including almost all massive stars form in massive dense clumps in Giant Molecular Clouds (GMCs), which can only be well traced by molecular dense gas tracers like HCN and CS. Studying dense gas in super star clusters in nearby galaxies down to GMC clump scales (~ 1pc) is a key step to connect star formation from the Milky Way to other galaxies. We propose to use dense gas tracer HCN 1-0, CS 2-1 and HCO+ 1-0 to study an enhanced star-forming cluster in the local group dwarf galaxy NGC6822, with a resolution of 1.3 pc. This will be the first dense gas study on active star-forming clusters outside the Milky Way with resolution down to GMC clump scales. We will exam the clump sizes, masses, and other properties under the super star cluster environment, and compare to those of dense clumps in our Galaxy. This will give crucial information in understanding the Kennicutt-Schmidt law in terms of dense gas. | High-mass star formation | ISM and star formation | 2018-05-12T00:37:58.000 |
| 3014 | 2019.1.01809.S | 39 | ALMA-SPONGE: the role of neutral hydrogen in diffuse interstellar chemistry | 21-SPONGE has obtained very sensitive HI absorption spectra in the direction of 57 background radio sources. In Cycle 6 we started to measure absorption of key molecular species in the diffuse ISM (HCO+, HCN, HNC and CCH) for 22 of 21-SPONGE sources. This proposal aims at completing the remaining sources for which we have not received observing time in Cycle 6. While commonly detected in the diffuse ISM, abundances and abundance variations of these molecular species are still not well understood. The HI spectroscopy provides key information regarding the kinematic temperature of gas, and its turbulent properties, allowing us to search for environmental and dynamical effects that play an important role in molecule formation and evolution. The key scientific objectives are: compare how the column density and line width of different species correlate with Ts and Ms, investigate the correlations of column densities of different species and compare with model predictions; and investigate the role of UV radiation field on both gas temperature and chemistry. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-01-07T22:09:47.000 |
| 3015 | 2018.1.01089.S | 43 | The Physical and Dynamic Properties of a Keplerian Disk Undergoing Infall | We propose Band 6 and Band 7 molecular line observations of the Class 0 system VLA 1623 at ~0.25 arcsec (30 au) resolution. Previous molecular line observations of VLA 1623 revealed a large Keplerian disk around one of the embedded stars in this system, VLA 1623-A, although contributions from infall could not be ruled out. Recent ALMA 1.3 mm dust polarization observations of this source show polarization morphologies consistent with an hourglass magnetic field, a strong signature of gravitational collapse and infall. Thus, VLA 1623-A appears to be a young, protostellar disk that may be accreting material from its infalling envelope. To explore this possibility, we will observe VLA 1623-A using tracers of infall, the Keplerian disk, and the gas temperature. We will H13CO+ (4-3) and H13CN (4-3) to identify infall motions from models. To improve these models, we will use C17O (3-2) to trace the Keplerian disk better than previous observations. Finally, we will use H2CO (J=3-2) lines to measure the gas temperature in the disk and constrain the non-thermal velocity component so that we can estimate a magnetic field strength. | Low-mass star formation | ISM and star formation | 2020-08-12T01:19:16.000 |
| 3016 | 2012.1.00882.S | 3 | Imaging the bright [CII] emission in a quasar host galaxy at z=7.1 | High redshift quasars are hosted by the most massive and luminous galaxies in the early universe. Over a year ago, we discovered a bright quasar at z=7.1, J1120+0641, providing a unique opportunity to study the physical processes in a forming massive galaxy at z>7. Our Plateau de Bure Interferometer observations revealed a strong (1.2x10^9 L_sun) [CII] emission line and the far-infrared continuum with a luminosity of 0.5-1x10^12 L_sun. Here we propose to obtain deep ALMA observations at high spatial resolution (~0.24 arcsec, or 1.2 kpc at the redshift of the quasar) to address key aspects that cannot be answered with the available data. In 69 minutes (on-source) of ALMA Band 6 time we will be able to (1) constrain the morphology and kinematics of the emission line gas, (2) produce a map of the star formation as traced by the far-infrared (FIR) luminosity, (3) look for a possible recent merger event and (4) derive a much more accurate dynamical mass. Since the derived far-infrared properties (dust temperature, FIR luminosity, SFR and L_[CII]/L_FIR ratio) of the two well studied highest redshift quasar hosts (J1120+0641 at z=7.1 and J1148+5251 at z=6.4) are strikingly different, it is imperative to expand the sample of quasar host at the highest redshifts. We therefore propose to quadruple the number of [CII] line and FIR continuum detections at z>6.5 by taking snapshot observations (~7.5 minutes on-source) of three new quasar hosts, that we have recently discovered between z=6.6 and z=6.9. Together with the z=7.1 quasar, these are the 4 highest redshift quasars known. The unprecedented sensitivity of ALMA will yield the detection of the [CII] emission line down to a flux of 1 Jy km/s (all z>6 quasar hosts with [CII] observations have line fluxes of >1 Jy km/s). These snapshot observations will already enable us to put the first constraints on the physical properties of the host galaxies at 6.6 | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2015-04-11T11:22:35.000 |
| 3017 | 2022.1.01137.S | 24 | Finding the calm in turbulent centers of AGN | We ask to observe the dense molecular gas in the nuclear region of four well-selected nearby AGN as probed by HCN(1-0), HCO+(1-0), and CS(2-1). These lines are easily observed in a single spectral setup for these targets, making this small pilot survey very efficient. The goal is to characterize the distribution and general kinematics of this dense gas and compare it to the dynamics of CO molecular gas from ALMA archival observations to investigate if the dense gas kinematics is suitable for probing the black hole mass in future studies. This is important since CO gas, used for weighing quiescent black holes, is often too turbulent or even absent in the centers of AGN. If dense gas is always present and in pure rotation, this offers a unique and important opportunity to develop mass determination methods for AGN based on molecular gas dynamics which - based on CO gas - are currently significantly challenged by the presence of strong outflows in luminous AGN. Since the dense gas is not well studied for AGN, this program will contribute important insight on this topic by itself. If dense gas is detected, these observations will also serve to help plan future follow-up observations. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-06-08T13:17:14.000 |
| 3018 | 2016.1.01236.S | 21 | The mass of the central black hole of AGN NGC 3227 measured with molecular gas dynamics | Accurate black hole mass measurements are essential to our understanding of the observed large-scale correlations between black holes and their host galaxies. Several independent methods are used to measure the mass of supermassive black holes in AGN hosts. However, they typically provide values that differ by up to an order of magnitude. We propose to exploit the exquisite spatial resolution and sensitivity of ALMA to measure the black hole mass in NGC 3227 from the dynamics of the cold molecular gas. This nearby AGN is the best target to compare reverberation mapping with dynamical black hole mass estimates. From near-IR adaptive optics data we know that within a radius of 0.1" of the galaxy centre the molecular gas velocity increases, a clear signature of the black hole potential. The distance to NGC 3227 and the high-quality ancillary data available provide the ideal setup to model the molecular gas dynamics at high spatial resolution. The proposed ALMA observations will allow us to start a campaign to compare dynamically measured black hole masses with reverberation mapping estimates and evaluate the systematic uncertainties and limitations of the various mass measurements. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-09-21T14:25:01.000 |
| 3019 | 2016.1.00747.S | 174 | Quantifying the Feedback Potential of Young Massive Protoclusters | In a series of radio and infrared surveys, we have identified a sample of 20 massive protoclusters existing in a specific evolutionary state in which outflows dominate their infrared appearance. Our SMA millimeter data at 3" resolution reveal high velocity CO emission (up to +-80 km/s) with complex morphology indicative of multiple actively-accreting protostars. We propose to test the theoretical idea that the combined outflow feedback is enough to maintain turbulence but not enough to disrupt the parental gas reservoir, thereby allowing star formation to proceed at a regulated rate. We will image 6 protoclusters on scales of 0.8"-20" for which we also have approved SOFIA mid-IR imaging observations. Using a set of outflow and hot core tracers, we will resolve individual outflows, identify their driving sources, and compute their momentum and energies. The combination of SOFIA and ALMA continuum imaging will enable measurements of the individual protostellar luminosities thereby allowing an accurate estimate of the contribution of radiative feedback. We will compare these results with the turbulent and gravitational energies of the gas and the dynamical mass of the cluster. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2018-05-31T23:44:05.000 |
| 3020 | 2023.1.01340.S | 0 | Circumplanetary Disk Masses, Sizes, and Evolution: From Case Studies to Population Statistics | Studying the accretion disks around planetary-mass companions (PMCs; M~10-30 Jupiter masses, orbits typically >100 AU) provides unique insights into the timescale of giant planet assembly and the initial conditions of exomoon formation. To date, the disks around PDS 70 c and SR 12 c are the only two circumplanetary disks detected by ALMA, indicating that deep imaging is necessary to probe disks in the planetary regime. We propose to observe 3 actively accreting PMCs in Band 7, with 3-5x greater sensitivity than previous ALMA non-detections. Multi-wavelength evidence indicates that our targets harbor disks rich in dust and gas, representing the best samples for deep ALMA imaging. We aim to increase the current census of circimplanetary disks from 2 (PDS 70 c and SR 12 c) to 5, compare disk sizes and masses with theoretical expectations, and test whether they follow the traditional scaling relationship from the stellar into the planetary regime. These deep observations may also detect CO(3-2) if PMC disks are relatively extended in gas emission. Even in the unlikely case of non-detections, we will still place stringent limits on the disk properties. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2025-03-18T21:34:21.000 |
| 3021 | 2021.1.00214.S | 11 | A second epoch of Serpens South's most spectacular outflow | A protostar driving a notably episodic outflow provides an observational signpost of episodic accretion. Our target source, named CARMA-7, is part of Serpens South that was mapped with ALMA in Cycle 2 at 1 arcsec resolution, and then targeted again in Cycle 5 with 0.14 arcsec resolution, equivalent to 60 au. At such high angular resolution, C7 reveals arguably the most complex structure in position-velocity space of any outflow observed at mm-wavelengths, as well as a chemically rich core, suggesting that it is actively accreting. We propose to use its apparent protostellar outflow variability as a proxy for accretion events. In order to better constrain its outflow characteristics, we need to know (1) proper motions and inclination angle; and (2) temperature structure along the jet. With this information, we will compile a mass-loss history for this young source, and investigate the link to accretion history. | Intermediate-mass star formation | ISM and star formation | 2023-03-29T20:33:50.000 |
| 3022 | 2021.1.00311.S | 610 | Submillimeter Continuum of Massive Star Forming Cores with Class II Methanol Masers | There are growing evidences suggesting that, similar those in low-mass young stellar objects (YSOs), luminosity burst phenomena also occur in massive star forming cores. Observationally, luminosity bursts in the submillimeter wavelengths have been witnessed toward at least two massive star forming regions by now, and the association of Class II methanol maser flaring events and the luminosity burst in massive star forming sites is very compelling and appealing. What is the frequency and degree of their submillimeter continuum variability in high mass star forming cores? To further explore the occurrence of luminosity variation and possible burst events associated with massive YSOs systematically from the observational viewpoint, it is imperative to monitor and search for such events over a statistically significant sample. To this end, we propose to conduct observations of massive star forming sites associated with 6.7 GHz methanol masers using the 12-m Array at Configuration C4/5 in Band 6. | High-mass star formation | ISM and star formation | 2023-08-22T20:02:34.000 |
| 3023 | 2022.1.00480.S | 255 | What is the size distribution of protoplanetary disks in nearby star-forming regions? | The size of a protoplanetary disk is a fundamental property that controls the potential architectures of planetary systems. However, protoplanetary disks seem to be significantly smaller than previously thought, and after many years of ALMA operations, the full size distribution of protoplanetary disks in star-forming regions remains to be established. The Ophiuchus Molecular Cloud has the largest number of disks within < 200 pc, but the vast majority of their disks are still unresolved. Here we propose to observe a sample of 100 disks in Ophiuchus at 0.05´´ - 0.10´´ (7 - 14 au resolution) in Band-8 to investigate how disk sizes vary as a function of stellar mass, SED Class, and multiplicity. Our results will serve as a benchmark for comparisons to other regions and will give better context to the results from ultra-high-resolution studies. By sharing calibrators in two Science Goals, this program is extremely efficient, allowing us to observe 100 objects in just 5.3 hs. | Disks around low-mass stars | Disks and planet formation | 2024-06-06T22:25:25.000 |
| 3024 | 2022.1.00604.S | 231 | Timing the Disappearance of Molecular Gas in Post-Starburst Galaxies | Theoretical predictions of the quenching process predict that the absence of molecular gas (via e.g., depletion, removal, or heating) should precede the cessation of star formation. However, recent ALMA CO(2-1) observations of z~0.7 post-starburst galaxies have revealed that galaxies retain significant gas reservoirs (log(M/M_sun)~10) after they shut off their primary epoch of star formation. Intriguingly, H2 is undetected in galaxies that quenched >~100 Myr ago, despite depletion times from star formation being ~25 Gyr. The current sample of 12 galaxies is too small to precisely time this disappearance and assess whether other galaxy properties help determine whether galaxies retain H2 (e.g., size, AGN activity, burst fraction). We propose to conduct a shallow survey to nearly quadruple sample size, while only doubling previous ALMA investments, thereby assembling the largest comprehensive sample of H2 measurements in quenched galaxies outside the local Universe. In conjunction with a rich set of ancillary data, this statistical census will conclusively describe disappearing H2 reservoirs and evolutionary timescales that will inform quenching models and cosmological simulations. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2024-02-02T00:43:19.000 |
| 3025 | 2013.1.00417.S | 4 | The cradles of giant galaxies: the ALMA view of the most powerful QSOs in the Universe | The most luminous QSOs in the Universe at z=2-4, hosting SMBH of >10^9 Msun, are likely the cradles of local giant galaxies. Despite their astrophysical importance they are still little studied in the sub-mm band. We propose to exploit the ALMA sensitivity to fill this gap by targeting 5 of the most luminous QSOs discovered by WISE at 22um. All our targets are BALQSOs with strong outflows of ionized gas. Our aim is to probe: (i) CO(3-2) for two QSOs at z~3, CO(4-3) for three QSOs at z=3.5-3.8; and [CII] and the nearby continuum to measure gas mass, SFR, and dynamical mass; and (ii) any outflowing molecular gas in the wings of [CII] and CO lines. The proposed observations are standard but applied to a unique sample and will allow us to: a) test if the AGN feedback has been already efficient in expelling gas; b) measure the gas consumption time to constrain the star-formation mode (starburst vs quiescent) of QSO host galaxies; c) locate the high luminosity QSOs in the MBH–Mgal diagram compared to the tracks which lead to the formation of local giant galaxies. Our results will provide a benchmark for our understanding of the AGN-host galaxy interplay during the luminous QSO phase. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2016-11-11T18:59:26.000 |
| 3026 | 2018.1.00929.S | 16 | Eris, Dysnomia, and the formation of Kuiper belt satellites | Our Cycle 3 observations of Eris -- the most massive known dwarf planet -- may have inadvertently detected its satellite, Dysnomia. In standard satellite formation models, Dysnomia should be tiny with a high albedo and thus undetectable with ALMA, but we have obtained a ~3.5 sigma detection consistent with a much larger much darker satellite at the predicted location of Dysnomia. If real, this detection will require significant revision of our understanding of collision and accretion in the outer solar system. We propose a single deep observation to either confirm the Cycle 3 detection or place stringent upper limits on the true size of this satellite. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2019-10-17T00:00:00.000 |
| 3027 | 2015.1.00708.S | 81 | Hearts of Darkness: A Look at the Most Heavily Obscured LIRGs with ALMA | With the IRS on the Spitzer Space Telescope we have been able to probe the energy sources, the dust and the warm molecular gas (H2) content on kpc scales in large numbers of low-redshift Luminous Infrared Galaxies (LIRGs). In a small fraction of LIRGs, there is so much obscuration (A_V > 50-100 mag) that even the mid-infrared gives us only the barest hint of the physical conditions in the circum-nuclear ISM that powers star-formation and fuels a central active nucleus. These highly shrouded galaxies are rare, yet very interesting because they may represent a brief transition phase in the evolution of a gas-rich merger to an optically visible QSO. Here we request 3.99 hrs to observe four of the most highly obscured, nearby LIRGs with ALMA in Band 7 to obtain maps of the circum-nuclear molecular gas in the HCN 4-3, HCO+ and CS 7-6 lines along with 872 micron dust continuum on 50pc scales. These data will provide the first high spatial resolution look at the mophology and dynamics of the dense molecular gas and dust in these galaxies, establishing an important baseline for future observations of dusty, merging galaxies at high-redshift. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-01-12T22:57:41.000 |
| 3028 | 2012.1.00242.S | 4 | Progenitors of Massive Galaxies in the Extremely High Density Environment around 4C 23.56 at z=2.5 | We propose ~ 0''.6 resolution band 3 CO(3-2) and band 6 continuum observations of ~ 10 dusty star-forming galaxies selected as strong Ha emitters and 1.1~mm sources at z = 2.48 around the radio galaxy 4C 23.56. Ha emitters show significant volume overdensity (x5) compared with the blank field, and surface overdensities of other class of massive galaxies such as extreme red objects, distant red galaxies, MIPS 24 um sources, IRAC red galaxies, and 1.1 mm selected submillimeter galaxies have been discovered. Therefore, this is one of the most promising protoclusters at z > 2, which is crucial for the study of formation and evolution of galaxies in the biased environment. In particular, the protocluster around 4C 23.56, the proposed target, is very unique because a protocluster which contains many massive starbursts with elevated star formation rates exceeding ~ 100 Msun / yr is very rare at z > 2, so far as known. Therefore, the targeted star forming galaxies will be the unique sample to investigate the systemic environmental effect of massive galaxy formation over cluster scale. We estimate the accurate star formation rates, gas masses, and dynamical masses for individual galaxies with star formation rate > 150 Msun / yr from dust continuum and CO(3-2) with high resolution and sensitive observation. Dust source identification and physical properties from CO line will be attained with ~ 0''.6 (~ 5 kpc) resolutions. From this observation, systemic enhancement and efficiency of massive galaxies formation on overdensity region will be quantified and compared with that of field galaxies. This is the first time to evaluate submm properties of many starburst galaxies within a protocluster at z > 2, and will be the large step to understand the origin of cluster formation. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2015-06-17T18:58:37.000 |
| 3029 | 2022.1.00295.S | 10 | A [CII] census in a giant Lyman-alpha blob at z=3 | Extended Lyman-alpha nebulae (so called Lyman-alpha blobs, LABs) provide a benchmark for the presence of plentiful hydrogen on circumgalactic-medium (CGM) scales and provides clues to understanding galaxy formation and evolution. One of the most spectacular LABs known to date is LAB1 in the SSA22 proto-cluster at z = 3.1. Recent ALMA observations revealed that the [CII] emission is widely distributed in a central 100 kpc region of SSA22-LAB1, also showing multiple major-mergers. To expand our understanding from one case study to the more general picture, we here propose to observe [CII]158um emission and dust continuum for another specutacular LAB in the same proto-cluster, SSA22-LAB2. In conjunction with MUSE/KCWI Lyman-alpha IFU data, we will uncover the ISM in and around galaxies associated with this giant LAB. Our immediate goals include to: (i) throughly uncover associated galaxies, including previously missed ones; (ii) determine the interplay between galaxies and surrounding medium; (iii) reveal the Lyman-alpha power mechanism; and (iv) diagnose how galaxy assembly occurred in this massive halo. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-10-11T10:45:17.000 |
| 3030 | 2015.1.00888.S | 66 | Probing disk structure in a cavity of pre-transitional disks around Sun-like young stars | It has become evident that protoplanetary disks have complex structures and capable of examining the inner region (a few x 10 AU) of protoplanetary disks. The Subaru Telescope has revealed that 2MASS J16042165-2130284, UX Tau A, and PDS 70 have a large cavity and, in conjunctionwith SED, have structure in their cavities, such as (proto)planet. Comparison of the appearance of the cavity/gap region at sub-millimeter wavelengths with the near-infrared data can be used to diagnose the planet mass and indeed whether the gap hosts more than one body. Our primary goal is to spatially resolve, comparable with Subaru images, and deeply observe the cavity near the mid-plane at mm/sub-mm wavelength in order to determine the size and the depth of the cavity of large dust and gas disk. We selected dust continuum, CO (J=3-2), and HCO+(J=4-3) for investigating dust and gas density structures in the large cavities. If emission inside of the cavity, which is probably influenced by planet, is detected, the companion mass can uniquely be constrained, and by augmenting the continuum measurement with gas data can constrain the location of at least the most massive bodies in the disk. | Disks around low-mass stars | Disks and planet formation | 2018-01-18T11:13:44.000 |
| 3031 | 2013.1.00474.S | 37 | Complete Census of Young Binaries in Lupus | We propose to carry out continuum imaging of Class 0 and I protostars in Lupus at band 7 with the ALMA. The main purpose of continuum imaging is a proto-binary survey: to determine the frequency, separation, and flux ratio (disk mass ratio) of binaries at the protostellar stage. ALMA’s high resolution comparable to typical separation of known proto-binaries (0”.15) and high sensitivity at submillimeter allow us to conduct a first complete survey of low-mass proto-binaries in Lupus. The band 7 continuum maps or visibility fit can reveal the configuration on tens of AU scale. HCO+(4-3) and CO(3-2) data will show how infalling envelope and outflow characteristics vary with evolution. The ALMA result will be an ultimate test of any theory to form a binary protostar and will identify unique sources to be followed up in the future. | Low-mass star formation | ISM and star formation | 2016-11-13T18:01:18.000 |
| 3032 | 2013.1.01342.S | 77 | Unveiling the blazar region with mm-wavelength observations: the ALMA-Fermi connection | The Large Area Telescope (LAT) onboard Fermi has revolutionized our knowledge of the gamma-ray sky. We found a highly significant (but strongly scattered) correlation between gamma rays and cm-lambda emission in blazars. This correlation has consequences for various topics, including the discrimination between models for the multi-lambda blazar emission and the contribution to the extragalactic diffuse gamma-ray background. We have developed a four-step strategy to address this topic in the mm-lambda regime, where we expect a much tighter correlation: 1-selection of a suitably sized gamma-ray blazar sample, 2-observations of the sample in ALMA Band 6, 3-analysis of simultaneous gamma-ray data, and 4-statistical discussion of the observational results to assess the existence, significance, and implications of the mm-gamma correlation. ALMA has a unique role in this context, as no other observatory can provide data on a statistically significant sample as the one proposed here. It is fundamental that the ALMA observations are carried out during the Fermi mission for simultaneity in the two bands. The project does not require advanced ALMA features, so it is ideal for Early Science. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2016-02-26T15:05:03.000 |
| 3033 | 2012.1.00198.S | 1 | Who Stirs the Pot? Dynamics of Edge-On Debris Disks | The tenuous, dusty debris disks around main sequence stars are hallmarks of substantial reservoirs of large planetesimals. The dynamical state of debris disks is central to our understanding of their masses, grain size distribution, and collisional evolution -- as well as the presence or absence of large bodies "stirring" the planetesimal belts. Edge-on debris disks present a unique opportunity to access dynamics, since the vertical scale height encodes the velocity dispersion and the total mass of any perturbing bodies. Millimeter wavelengths are uniquely suited for revealing the dynamical state of debris disks, since the large grains are not subject to the excitatory effects of stellar radiation that puff up the vertical scale height at optical and infrared wavelengths. Here we propose to measure the vertical scale height of the debris belts around the two brightest, most prominent nearby edge-on systems: beta Pic and AU Mic. The observations will reveal whether the collision velocities are destructive or erosive, and will be sensitive to perturbing masses as low as 2 and 5 earth masses in AU Mic and beta Pic, respectively -- potentially revealing the presence of Neptune-mass planets at large distances from these young stars. | Debris disks | Disks and planet formation | 2016-08-27T08:12:19.000 |
| 3034 | 2015.1.00035.S | 14 | Resolving atomic gas in the accretion flow surrounding Sgr A* | The Galactic center uniquely provides the opportunity to resolve the accretion flow onto the supermassive black hole on scales less than 5 pc. Our previous GBT-100m and SMA observations of molecular lines have revealed that the well-known 2-4 pc Galactic circumnuclear disk (CND) may consist of a convergence of several >2 pc scale molecular gas streams. The ionized mini-spiral arms in the inner ~1 pc radius further indicate that a portion of these molecular gas streams may penetrate inside the CND. However, the previous 22" resolution OI line observations suggested that the ionized mini-spiral arms may be merely the ionized rim of the ~10 times more massive atomic gas streams. With this proposal, we seek to take advantage of the new CI observation capability of ALMA Band 8, to resolve these atomic gas streams at subarcsecond resolution. The aim of this proposal is to unveil detailed morphology and kinematics of the atomic accretion flows for the first time, and by using both the spatial distribution and the observed velocity field of the atomic gas, we will diagnose how it survives the ionizing flux when approaching the central OB cluster and the black hole. | Galactic centres/nuclei | Active galaxies | 2017-06-29T22:22:58.000 |
| 3035 | 2019.1.00145.S | 5 | Filamentary streamers, accretion flows, multiplicity and disks in the proto-O star W33A | We propose to follow-up our Cycle 1 (delivered in Cycle 2) observations to fully trace the 3D velocity field of the material accreting onto a newly forming O-star. Our target, W33A, a proto-O-star, is nearby (2.4 kpc) and well studied, already having a rare combination of high resolution observations at near-IR (Gemini-AO- 0.13") and mid-IR (VLTI-MIDI - 0.04") plus our Cycle 1 data (~0.3"). Our ALMA data show a spiral filament feeding material to the central region, where the velocity profile show signs of rotation, suggesting the O-star is forming via a disk. This `disk' appears disrupted by infalling streams (we find at one on 1000au scales - Maud et al. 2017 MNRAS 472 120), fragmentation due to gravitational instability, or interaction with companions. However, we have not yet resolved the disk scales <500au of the system to determine which is the case. Our 3D radiative transfer models (dust & gas) including infall from the outer rotating envelope onto a compact system best matches the binary scenario (disk radii <250au). ALMA will reveal the answer, as it is the only instrument that can zoom in and image the sub-100au scales, allowing us to test massive star formation theories. | High-mass star formation | ISM and star formation | 2022-10-08T23:39:53.000 |
| 3036 | 2015.1.00616.S | 1 | A search of the elusive sub-mm polarisation in protostellar disks | We propose to use ALMA in its narrow-field polarimetry mode to detect sub-mm polarized emission for the first time in a protoplanetary disk. ALMA's high resolution will avoid smearing out of the polarized signal, giving a 5x improvement in beam size and a factor of 100 improvement on the polarised flux over previous studies. The well-studied nearby disk HD163296 is ideal for this work, and we will image the polarisation out to a radius of 145AU to 0.3% rms, giving 60 vectors over the map and 12-15 vectors at the ALMA polarisation sensitivity limit of 0.1% (out to 100AU radius). The orientation and structure of polarisation vectors will allow us to pinpoint the grain alignment mechanism and the degree of alignment and grain non-sphericity. Even a non-detection will provide stringent limit on the shape of mm-sized grains, turbulent mechanisms hampering grain alignment and upper limits to alignment mechanisms. This is a resubmission of a Cycle 2 project (2013.1.00053.S) which was awarded time but no data has been taken, so far. Should the programme be executed in full in Cycle 2, it would not need to be repeated in Cycle 3, and we would withdraw the proposal. | Disks around low-mass stars | Disks and planet formation | 2018-03-02T12:16:03.000 |
| 3037 | 2018.1.00567.S | 220 | Verifying the Robustness of Faint Submm Sources Detected in ALMA Deep Surveys | ALMA deep surveys have shown that the contribution of faint submm sources to the cosmic star-formation rate density (SFRD) is significant at z ~ 2-3 and it sharply drops off at z > 3. However, the estimation still has a large uncertainty because in previous studies the source robustness highly depends on the identification of optical/NIR counterparts, and sources without counterparts are regarded as spurious and not adopted. It is possible that this method miss real sources which could significantly contribute to SFRD at z > 3. We propose follow-up observations of faint submm sources detected in our ALMA deep survey in GOODS-S to see if the detections are robust or not. The fraction of sources without K-band counterparts is higher than estimated statistically, suggesting that at least a part of them are real. The SEDs suggest that they are dusty starbursts at z > 4. If the sources without counterparts are real, the contribution to SFRD increases by a factor of 5 and becomes comparable to UV-selected galaxies. By confirming the detections independently in new observations, we will verify the previous method and establish a more reliable method of evaluating source robustness. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2020-07-18T14:50:21.000 |
| 3038 | 2023.1.00431.S | 0 | First measurement of the water abundance and D/H ratio in a mature protoplanetary disk | Water is a crucial ingredient for the chemistry and physics of planet formation. Despite its importance, constraints on the water abundance in protoplanetary disks are extremely limited, and the bulk water reservoir is thought to be mostly hidden in midplane ices. Excitingly, recent observations revealed high gas-phase abundances of tracers of O-rich ice desorption towards the dust trap of the Oph IRS 48 disk. This is a prime opportunity to directly access the water reservoir in a mature disk. We propose to target H2(18)O and HDO lines in Bands 5 and 6 towards Oph IRS 48 to directly measure the H2O abundance and HDO/H2O ratio. This program will provide novel insights into the abundance and origin of water in a mature disk, essential to our understanding of planet formation and planetary habitability. | Astrochemistry | ISM and star formation | 2025-09-04T13:53:15.000 |
| 3039 | 2022.1.00898.S | 13 | Quest for the source: connecting a filament to infalling gas towards a protostar in Barnard 5 | The classical picture of star formation involves the gravitational collapse of a dense core, but without any connection to its environment (the larger molecular cloud). Streamers of infalling material from the envelope towards disks around young stellar objects have been detected in all stages of the star formation process (Class 0 to Class II), which suggest that the local environment plays a crucial role on star- and disk-formation up to later stages than previously thought. However, the full extent and their contribution to the protostars mass budget is lacking. This stops us from carrying out a thorough assessment of how relevant streamers are to the star-formation process. Our goal is to investigate the origin of the streamer found towards B5IRS1, a Class I protostar in Barnard 5. We propose a mosaic observation at intermediate scales (1-1.5" beam), between the filament (5" beam) and the high-resolution streamer observations (0.4" beam) that already exist, to follow the gas motions using the same molecule at all scales. This is the first attempt to connect infalling gas to the filament where a protostar is embedded. For this purpose, we request 4.8h of the 12m array. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-10-31T17:21:53.000 |
| 3040 | 2018.1.01037.S | 199 | Formaldeyde distribution and formation in embedded T Tauri disks | Simple organics such as formaldeyde (H2CO) are the bricks for the formation of complex organic and prebiotic molecules. To constrain their abundance and distribution in protoplanetary disks is key to understand organics inheritance/formation and transfer to the forming planets. While H2CO has been imaged in two protoplanetary disks, the chemistry of less evolved T Tauri disks still embedded in their envelope is poorly explored. Despite the difficulty to disentangle the different emitting components in strongly accreting/ejecting systems, these are associated with brigth H2CO emission, hence are ideal to investigate organic chemistry in disks. Recently, our team imaged a ring of H2CO in the embedded disk of DG Tau located beyond the CO snowline (~30 AU) and extending byond the edge of the millimeter dusty disk. Disk modeling indicates that gas-phase processes and desorption from grains cannot account for the observed intensity and suggests that H2CO is formed in situ on the ices beyond the CO snowline. Based on the test-case of DG Tau we propose a survey of H2CO in a sample of embedded T Tauri disks to investigate the distribution and formation of simple organics. | Astrochemistry | ISM and star formation | 2020-08-06T13:38:34.000 |
| 3041 | 2017.1.00855.S | 64 | Opacity Variability in Uranus's Troposphere | We request ~3.7 hours to observe Uranus in Bands 3, 4, and 6. The spatially resolved millimeter maps will reveal brightness temperature variations in Uranus's troposphere from 0.1-5 bar due to latitudinal variations in opacity. By observing in multiple bands we will distinguish the identities and abundances of the major absorbers, e.g. CH4, H2S, or ortho/para H2, for the first time. Mapping the brightness variability and discovering its source are crucial for understanding Uranus's atmospheric circulation pattern. | Solar system - Planetary atmospheres | Solar system | 2019-09-27T15:56:34.000 |
| 3042 | 2017.1.01572.S | 365 | ALMA Observations of Resolved Extragalactic Jets in a Critically Unsampled Spectral Window | We propose high-resolution continuum imaging in bands 3 and 6 of nine X-ray detected radio jets, in order to accurately map the spectral energy distribution in the critical window between radio and infrared. Our previous program on extremely powerful jets has revealed that the spectral energy distributions of these jets are more complex than previously understood, with multiple emission components of unclear origin, which are likely related to the unknown particle acceleration mechanism. This program is meant to compliment our previous program by selecting a sample with a range in morphology and extending down to low jet powers. These observations are critical to sampling the synchrotron spectrum of these resolved jets in a previously unexplored window, where our previous assumptions about the SED appear to be breaking down. In the case of 2101-490 (part of our previous program), we request band 7 observations to confirm the completely unexpected turnover in the radio synchrotron spectrum which reveals that at least three distinct emission components are present in the jet. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-02-26T15:59:25.000 |
| 3043 | 2016.1.01155.S | 35 | Resolved star formation and molecular gas distribution in the most distant cluster at z=2.506 | We propose 0.2"-resolution CO[3-2] and 870 um continuum observations of a remarkably dense structure with extended X-ray emission at z = 2.506 recently discovered in COSMOS (Wang+2016, submitted), which is arguably the most distant X-ray detected cluster known to date. This structure is also unique in its high concentration of massive galaxies and enhanced star formation activities, containing 11 massive galaxies (3 AGNs) within a 10" radius with a combined star formation rate of 3400 Msun/yr. These properties suggest that we are witnessing the rapid formation phase of a dense cluster core, the missing link to understand the build-up of cluster ellipticals. With a single pointing, the proposed observation will spatially resolve the molecular gas and dust distribution for 6 cluster members that were already detected in CO[1-0] with JVLA. This will enable the most comprehensive study of star formation and ISM properties in a dense environment at the key formation epoch of a massive cluster. The extent of gas and dust distribution, the gas kinematics and resolved star formation efficiency will provide crucial constraints on the formation mechanisms of cluster ellipticals. | Galaxy Clusters | Cosmology | 2018-09-09T18:53:48.000 |
| 3044 | 2013.1.00279.S | 3 | A Complete Line Survey Observation in the 3-mm Band toward NGC 1068 for Diagnosing the Power Source in Galactic Nuclei | We propose to obtain high resolution images of molecular distribution from a complete line survey observation in 3-mm band toward NGC 1068. The chemical properties have been expected to be powerful astrophysical tools for the study of galaxies, because the molecular line observations of different galaxies allow us to study the effects of these different physical properties/activities on the molecular medium. So far, some groups have suggested that it is possible to diagnose power sources in dusty galaxies using molecular line ratios. It is the workable strategy to clarify the relationship between the physical properties and the chemical markers in nearby galaxies, in order to understand the power source of distant and dusty galaxies using the molecular lines. We carried out the line survey toward NGC 1068 with the Nobeyama 45-m telescope. And also, our ALMA cycle-0 (PI S. Takano) and cycle-1 (PI S. Takano) proposals toward NGC 1068 in 3-mm band were accepted and we already received cycle-0 data. Therefore, we can combine these data and we will obtain the complete line survey toward NGC 1068 in 3-mm band. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-12-02T23:46:26.000 |
| 3045 | 2022.1.00005.S | 0 | Scrutinizing a dense molecular torus in the archetypal AGN NGC 1068 | We propose ALMA 0.012" (<1 pc)-resolution band-7 (275-370 GHz) HCN J=4-3 line observations of the nucleus of the nearby (14 Mpc) archetypal luminous AGN, NGC 1068. Previously obtained ALMA data of HCN and HCO+ J=3-2 lines in band 6 (211-275 GHz) clearly revealed a long-sought-after east-west-oriented, rotating dense molecular torus in NGC 1068. However, it was also found that the dense molecular torus looks counter-rotating between inner and outer part, much more complicated than a classical torus picture. We aim to better scrutinize a cloud-collision scenario toward the western torus from the far side, by combining the proposed high-angular-resolution HCN J=4-3 line data with existing data. Our ultimate goal is to obtain an important clue about how to fuel a central supermassive black hole in the luminous AGN population, by removing angular momentum in the torus. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-04-22T14:21:32.000 |
| 3046 | 2015.1.00625.S | 12 | Star Formation Triggered by the Collision of Supergiant Shells in the Large Magellanic Cloud | We propose CO observations of the unique massive star forming region N48 in the Large Magellanic Cloud, where two Supergiant Shells (SGSs) LMC4 and LMC5 are colliding. We propose observations of 12CO(2-1), 13CO(2-1), C18O(2-1) covering three clumps in different evolutional stages. To understand how clusters are formed through the collision of SGSs, we need to reveal the properties and states of pre-cluster forming cores and filaments with resolutions higher than 1 pc. With these resolutions, we will reveal the detailed spatial distribution, velocity structure of the molecular filaments at sub-pc scales which simulations predict. We will also clarify whether there are differences in the characteristics of pre-cluster forming dense molecular cores. The mechanism of Young Massive Cluster (YMC) formation can be well compared with theoretical models for the first time. Such study will yield vital clues as to the formation of YMCs via cloud-cloud collision. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2017-09-06T10:53:56.000 |
| 3047 | 2016.1.01158.S | 36 | Clumpy rings in HD 169142: catching the formation of pebbles | Determining the dust characteristics and distribution in (pre-)transitional disks could be key to understand the early processes of planet formation. However, the dense regions where planet embryos are formed may be optically thick at sub-mm wavelengths, as we recently found in the young disk of HL Tau. In that study, we combined high quality images obtained with VLA and ALMA (wavelengths 0.87 to 7 mm), and inferred fast grain growth, fragmentation, and formation of dense clumps in the inner parts of the HL Tau disk. Here we propose ALMA observations at band 3 to extend this study to the pre-transitional disk of HD169142. We have already obtained multi-configuration 7 mm data with the VLA. By combining the proposed observations with our VLA maps we will carry out a complete analysis of the dust distribution throughout the disk. HD 169142 is more evolved than HL Tau and therefore, we expect to find a more severe fragmentation and a higher degree of grain growth near its ring and its two gaps. Studying these two disks at different evolutionary stages will allow us to better understand the evolution of the dust properties, eventually leading to the formation of planets. | Disks around low-mass stars | Disks and planet formation | 2018-10-05T22:12:58.000 |
| 3048 | 2019.1.00458.S | 92 | What is Carving the Gaps in Young, Embedded Disks? | Protoplanetary disks with ages of 1-5 Myr are often found with large holes in their centers. These "transition" disks are hypothesized to be carved out by planets hiding in the inner regions of the disk, and indeed some evidence has been found for planets hiding in such gaps. In our ALMA Cycles 3 & 4 observations of young (<0.5 Myr) embedded disks, we found several cases of embedded protostars that have a large cavities in their disk as well. However, our existing observations are insufficient to determine the underlying cause of these holes, whether it be large bodies such as planets or protostars, dust grain growth, or photoevaporation. Here we propose to observe a sample of 7 Class 0/I "transition disks" in continuum and gas lines to determine the clearing mechanism. Planets, multiplicity, dust grain growth, and photoevaporation each leave a distinct imprint on the dust and gas, and our proposed observations will have the power to distinguish between each scenario. If planets could be shown to be carving this hole, it would place very strong constraints on the timescales on which planet formation begins. | Low-mass star formation | ISM and star formation | 2023-02-11T20:59:47.000 |
| 3049 | 2019.1.00221.S | 33 | Mapping the molecular gas reservoirs of recently-quenched galaxies | Our ALMA survey of massive z~0.6 post-starburst galaxies has revealed that recently-quenched galaxies can retain significant- and puzzling- molecular gas reservoirs. Our detections of up to ~5*10^10Msun of gas represent the first detections of molecular gas in quenched galaxies outside of the local universe, and indicate that quenching does not require the total removal or depletion of molecular gas. However, we still do not understand the physical processes preventing this abundant gas from forming stars. Here we propose follow-up observations of three of these gas-rich quenched galaxies to map their gas distribution and velocity structure using high-resolution CO(2-1) data. These observations-- in conjunction with the stellar kinematics, 1.4 GHz continuum, and high-resolution imaging we are obtaining for these targets-- will allow us to compare the stellar and gas morphology and kinematics, search for signs of merger activity or outflows, and place these galaxies on the Kennicutt-Schmidt relation. This analysis will help constrain the physical mechanisms that quenched star formation in these galaxies without depleting the molecular gas. | Galaxy structure & evolution | Galaxy evolution | 2022-12-20T22:03:21.000 |
| 3050 | 2016.1.00935.S | 35 | How much dense gas is in turbulent disks, and how does that relate to clump properties? | The formation of dense molecular clouds is likely a key, regulating component of star formation and hence galaxy evolution. However, in distant galaxies, tracers of high density gas are difficult to observe. While over 200 galaxies at z > 1 have detections of molecular gas, to date only 5 galaxies have measurements of high-density gas tracers. Therefore, the physical conditions of star forming gas during the peak epoch of galaxy evolution (z=1-3) remains essentially unconstrained. We propose to address this with observations of HCN emission in the DYNAMO sample with ALMA. By exploiting the nearness of the DYNAMO galaxies we can measure dense gas ratios with straightforward methods used on low-z galaxies (ie. HCN/CO). Furthermore, we intend to use our already in hand data from HST and Keck to make direct comparisons of the global dense gas ratio to the properties of giant clumps within the galaxy. We can thus build a more complete physical picture of galaxies like those in the peak epoch of galaxy evolution. | Starbursts, star formation | Active galaxies | 2018-04-04T20:12:02.000 |
| 3051 | 2019.1.00951.S | 1111 | Characterizing Protoplanetary Disks in the Orion L1641 Region | Here we propose to greatly expand and diversify the sample of young disks observed in the millimeter with Lynds 1641 (L1641), a populous ~1 Myr region located within the large Orion Molecular Complex at a distance of ~400 pc. L1641 contains a broad range of stellar assemblages, masses, and disk evolutionary states, permitting a comparative study of disks across these properties. We will search for correlations of the vertical structure (disk settling) and disk dust masses between various spectral types (F0-M8), disk types (full vs. transitional disks), and star-forming environments (isolated vs. clustered). We propose to observe 101 disks in L1641 at 1.3 mm (band 6) with a flexible resolution range of 0.5" to 1.5" (200-600 AU) to create one of the largest catalogs of ~1 Myr old protoplanetary disk masses and demographics yet. This large and well-characterized sample will contribute to future debates on the process of planet formation as it provides key information for a unique region to study fundamental disk properties across a broad range of conditions. | Disks around low-mass stars | Disks and planet formation | 2021-04-13T20:59:15.000 |
| 3052 | 2015.1.00370.S | 29 | The Most Detailed View of the Double Nucleus in NGC6240 | Major galaxy mergers are particularly important for galaxy evolution as they can funnel fuel (gas) into the center of the galaxy, triggering both star formation and an active galactic nuclei (AGN). NGC6240 is the prototypical and best studied major merger hosting two supermassive black holes (SMBHs) accreting simultaneously. We propose to obtain long baseline ALMA band 6 observations of the CO(2-1) and dust continuum emission in the center of this galaxy, including the two nuclei and the region between them. This will provide an unprecedented map of the molecular gas at ~15 pc resolution, which represents a 10x improvement over existing observations. These unique data will allow us to identify individual star-forming molecular clouds and measure their kinematical properties. We will also be able to spatially resolve the gas in the sphere of gravitational influence of each SMBH, and hence study the properties of the gas that eventually is going to feed them. The proposed observations will shed new light on how these intense star formation and black hole growth episodes takes place and on the interplay between them, in this critical and still mysterious phase of galaxy evolution. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2017-03-18T16:51:53.000 |
| 3053 | 2016.1.00915.S | 27 | An anatomy of massive, cold, and highly deuterated cores next to warm/hot cores | High-mass stars form in massive molecular clouds or clumps, which appear to collapse and fragment in a hierarchical fashion, forming dense cores which then further fragment into more compact condensations. The physics controlling these processes is subject to intense debates, invoking at least gravity, turbulence, and magnetic fields. Recent high-resolution studies of warm/hot cores with ongoing high-mass star formation argue for a pure thermal Jeans fragmentation, while studies of massive cold cores in IRDCs suggest an crucial role played by turbulence. We detect massive, cold, and highly deuterated cores around warm/hot star-forming cores with the CARMA, SMA, and JVLA observations. These cold cores seem to be starless and likely prestellar, and could provide insights into the initial conditions of high-mass star and cluster formation. Being close to warm/hot cores actively forming high-mass stars, they also provide great opportunities for a comparative study of the dynamics of massive cores without significant environmental effects. Here we propose for ALMA observations, aimed at revealing the fragmentation, turbulent, and potential star-forming properties of these new cores. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-03-27T18:01:46.000 |
| 3054 | 2012.1.00657.S | 4 | Effects of active galactic nucleus and starburst in the nearby galaxies NGC 1068 and NGC 253: High resolution images of CN, SO, and HC3N at the 100 GHz region | We propose to obtain high resolution (~0".75) images of CN, SO, and HC3N at the 100 GHz region (band 3) toward nearby galaxies NGC 1068 and NGC 253. So far more than 40 molecular species have been found in external galaxies. The study of their abundances and the understanding of physical and chemical processes are a fundamental for astrophysics and astrochemistry of galaxies. One of the interesting topics is the effect of X-ray produced by AGN (active galactic nucleus) to molecular abundances. We carried out molecular line survey observations toward the nearby galaxy NGC 1068 with AGN and the prototypical starburst galaxies NGC 253 and IC 342 with the Nobeyama 45m radio telescope to study molecular abundances and to prepare for ALMA proposals. Our ALMA cycle 0 proposal was accepted, and we already received a part of data (2011.0.00061.S, PI S. Takano). Images obtained at the band 3 toward NGC 1068 (beam size of about 4”.3 x 2”.4), covering the central nuclear region and the surrounding starburst ring, demonstrated clear distributions of molecules in one or both of these extreme regions. These images are excellent for the study of physical and chemical processes. Based on these results, following observations are mainly proposed. (1) We continue to obtain the above clear images of other molecules at the band 3. CN (N=1-0) is selected as one of the key molecules to study the effect of X-ray. (2) Simultaneously high resolution (~0".75) images are necessary to compare with results of model calculations at the < 100 pc scale. In addition to CN (N=1-0), we selected related interesting molecules HC3N (J=11-10) and SO (J,N=3,2-2,1) for the ALMA cycle1 observations. | Astrochemistry | ISM and star formation | 2016-11-17T22:16:15.000 |
| 3055 | 2016.1.00070.S | 2 | High-energy electrons in magnetic reconnection | Particle acceleration is a ubiquitous phenomenon in almost all space and cosmic plasmas, yet the details of the mechanisms driving the particle acceleration remain poorly constrained observationally. The Sun, due to its proximity and dynamics, is arguably the best astrophysical laboratory, but even there the problem of particle acceleration remains a mystery and represents a great challenge both theoretically and observationally. Our prior work with microwave imaging data in combination with X-ray data suggests that acceleration regions are localized around the point of ongoing magnetic reconnection. However, the available observations never had the spatial resolution and image fidelity needed to resolve the acceleration region and study its spatial structure and time evolution. Here we propose to make observations of nonthermal emission from microflares to detect and quantify the particle acceleration at the Sun with the level of detail not yet available before. To maximize the chances to clearly isolate the nonthermal emission from a microflare, we propose to make observations above the limb, where the background optically thin coronal thermal emission is relatively weak. | The Sun | Sun | 2018-08-10T17:03:41.000 |
| 3056 | 2017.1.00070.S | 18 | Dissecting the Molecular Inflows and Outflows in the Seyfert 2 Galaxy Mrk 573 | We will obtain ALMA CO(3-2) and CO(6-5) observations of the Seyfert 2 galaxy Mrk 573 at ~0.1 arcsec resolution to map the distribution and kinematics of the molecular gas near the central active galactic nucleus (AGN). These observations will provide valuable insight into the feeding and feedback processes in AGNs by complimenting our HST and Gemini NIFS census of the velocity fields and geometries of the ionized gas, stars, and warm molecular (H2) gas. We find strong evidence for in situ radiative driving of ionized gas away from rotating molecular gas/dust spirals within ~500 pc (~1.5 arcsec) of the supermassive black hole (SMBH) in the so-called narrow-line region (NLR). We also detect warm molecular (H2) gas inside of ~500 pc that is outflowing after subtraction of the stellar velocity field from the CO IR bandheads. Our objectives for the ALMA observations are to: 1) identify the pathway for fueling the AGN and its kinematics, geometry, and connection to the outflow, and 2) determine the distribution and mass of the reservoir of molecular gas and compare to our derived mass outflow rates to probe the mechanisms of AGN and star formation feedback and shutdown. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-05-28T22:36:44.000 |
| 3057 | 2015.1.01448.S | 32 | High Resolution Observations of the Dense Gas in NGC 6240 | We propose high spatial resolution (0.12''~60pc) standard science observations of the HCN, HCO+ J=3-2 (S/N~20) and H13CN, H13CO+ J=3-2 (S/N~5) spectral lines in the luminous infrared galaxy merger, NGC 6240(z=0.0245). These observations will allow us to study the distribution, kinematics and excitation of the dense molecular gas in this extraordinary galaxy at an unprecedented level, making use of the unmatched sensitivity and resolution of ALMA. We will determine if the 12C/13C ratio is truly elevated in NGC 6240 or if the apparent enhancement is a purely chemical effect, with significant ramifications for star formation in luminous starbursts. With these data we will also search for chemical traces of the launching region of the extended molecular outflow seen in CO, using resolved line ratios of both the main and isotopologue species. The SiO line will be used to identify shocked regions, within the internuclear molecular gas disk and within the nuclei themselves, further adding to the obtainable kinematic information. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-03-31T18:36:42.000 |
| 3058 | 2021.1.00690.S | 16 | Searching for the signatures of gravitational instability in a protoplanetary disk | Gravitational instability (GI) is a fundamental process that plays a crucial role in disk evolution and planet formation when present. It occurs in disks with a sufficiently high disk-to-star mass ratio. Despite its importance, it has been difficult to confirm GI in real disks, mainly due to the large uncertainties associated with disk mass estimates using conventional methods. Recently, a new technique has been proposed to search for the kinematic evidence of GI through its characteristic "wiggles" in channel maps of molecular emission. This signature is present across the entire disk azimuth and radius. We propose to carry out ALMA Band 6 observations of 13CO and other species of the protoplanetary disk around AB Aur. The main goal is to confirm that the disk is currently undergoing GI using the newly proposed technique. AB Aur is a well studied young stellar object that has shown strong signs of GI in multi-wavelength observations in the past. Our program is posed to provide the most direct and clearest evidence of GI in a planet-forming class II disk to date. We also aim to pioneer a new technique to examine GI in disks using gas kinematic observations. | Disks around low-mass stars | Disks and planet formation | 2023-07-28T19:18:20.000 |
| 3059 | 2013.1.01172.S | 13 | CO isotopic ratio enhancement of Pa alpha-selected merging luminous infrared galaxies | Elevated CO(1-0)/13CO(1-0) line ratio from 20 to 50 is often observed in the nucleus of infrared-bright merging galaxies. The mechanism is not fully understood yet although CO and 13CO emission are most useful extragalactic gas tracers. Our cycle 0 observations toward mid-stage merger VV114 demonstrated that high CO/13CO abundance ratio is more important to the elevated CO/13CO intensity ratio than low optical depth of the CO emission in the intense star-forming regions of the system. To develop the results for other galaxies, we propose 5.3 hours of ALMA cycle 2 time to obtain 1".0 resolution high-S/N CO(1-0), CO(2-1), 13CO(1-0), and 13CO(2-1) maps for 2 gas-rich merging galaxies, NGC 1614 and NGC 3110, enough to estimate gas conditions using an excitation analysis. | Merging and interacting galaxies, Surveys of galaxies | Galaxy evolution | 2016-04-02T18:44:39.000 |
| 3060 | 2015.1.00212.S | 13 | Dense Molecular Gas Mapping of the Node in the Cosmic Web at z=3.1 | A remarkable large-scale structure like a progenitor of the Great Wall has been found at z=3.1 in the SSA22 field. There are three-dimensional filamentary structures traced by a hundred of Ly-alpha emitters (LAEs) and we mapped the 2x3 core region in ALMA Cycle2 at 1.1mm (the ALMA Deep Field in SSA22 or ADF22). Consequently, we found a rich cluster of dusty starbursts composed of 8 ALMA sources with spec-z = 3.09, suggesting the vigorous star-formation activity as well as enhanced AGN activity fueled by a large amount of molecular reservoir at the core of the large-scale structure. Here We propose a complete scan of CO(3-2) in ADF22. Our science goals are (i) Establishment the excess of cosmic H2 mass density at the core of the large-scale structure (ii) Unveiling the individual nature of discovered CO(3-2) emitters (iii) Clarifing the environmental dependence on the gaseous nature of SMGs, QSOs, and main-sequence galaxies. The propsoed observations will allow us to illustrate the on-going gas mass assembly in the large-scale structure for the first time. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2018-03-02T23:07:14.000 |
| 3061 | 2023.1.00455.S | 0 | How low-mass-star clusters disperse their natal clouds in the Orion A tail. | Low-mass-star formation is the key to understanding the origin of our home, the Sun and the Earth, and the origin of terrestrial life. Outside of massive star forming regions, most low mass stars also form in clusters. How these clusters disperse their natal clouds is still unclear, but it is the critical step to understand the initial status of Sun-like stars and their planets. We have identified 12 low-mass-star protoclusters in the southern tail of Orion A and found very rich patterns in star-cloud relationship. They form nearly a complete low-mass-star cluster evolutionary sequence. We propose mosaicking isotopic CO 2-1 lines and continuum using ACA alone to five of them that are likely actively shedding their natal clouds. The ACA data will help us discern all strong star-cloud interactions. Combining the ACA data with Herschel and Spitzer archival data will allow us to establish the first ever full picture of low-mass-star cluster formation in one place in the solar neighborhood. | Low-mass star formation | ISM and star formation | 2025-08-14T13:06:04.000 |
| 3062 | 2012.1.00248.S | 0 | The molecular jets of the proto-planetary nebula HD101584 | It is well established that bipolar jets dominate the rapid transition from the asymptotic giant branch (AGB) to the planetary nebula (PN) phase and it is widely conjectured that the jets are driven by interactions with a binary companion. HD101584 is among the most powerful proto-PN jet systems, and is unique in having a companion that was engulfed by the AGB star during the interaction, and survived. We propose to observe the HD101584 system in the 12CO, 13CO, and C18O J=2-1 lines to image the ejection geometry at high angular resolution, to determine the kinematics of the outflows, and to measure the energetics of the jet components. Comparison with the envelope binding energy and the in-fall energy released by the companion will provide important constraints on models of the binary interaction mechanism. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-06-11T15:44:07.000 |
| 3063 | 2015.1.00326.S | 14 | A detailed view of the Bird's anatomy: SF/AGN feedback | The Bird is a luminous infrared galaxy (LIRG), logL_IR(L_sun)=11.89, product of a triple merger. The ongoing star formation (SF) in the least massive of the components (the head) outshines that of the primary nuclei (the heart and the body) as evidenced by our Spitzer-24um imaging, hence dominating the LIRG phenomenon in the Bird. This clashes with the commonly accepted major merger scenario in which the SF is expected to be higher in central compact regions. Based on our recent ALMA cycle 2 CO 1-0 observations, we infer the presence of a (in/out)flow from one of the main nuclei. This could be a factor contributing to the apparent SF starvation. In this cycle 3 proposal we aim at investigating the SF/obscured-AGN feedback in the Bird, and how this influences the ISM of this striking object. | Merging and interacting galaxies, Outflows, jets, feedback | Galaxy evolution | 2017-07-29T16:22:35.000 |
| 3064 | 2017.1.00279.S | 63 | ALMA MAPS OF JUPITER DURING THE JUNO ERA | We request time to observe Jupiter with ALMA, as part of a dedicated world-wide campaign to support the Juno mission by providing global context images at radio-wavelengths for the Juno microwave radiometer data. We will observe continuum radiation in Bands 5 and 6, optimized to cover the H2S absorption band. We request oservations over a full rotation of the planet (2x~5.5 hr separated by 25 hrs), at a spatial resolution of ~1''. We plan to construct longitude-resolved maps of the planet. Through the simultaneously planned world-wide campaign we obtain data over a broad range of frequencies to characterize, via a joint analysis, the planet's atmosphere (composition, temperature, dynamics) from the stratosphere down to hunderds of bars. | Solar system - Planetary atmospheres | Solar system | 2019-06-11T21:52:43.000 |
| 3065 | 2016.A.00022.S | 75 | ACA characterization of the extended intra-clump emission in Super-Cluster precursors in the Galactic Center 100-pc ring | The formation of Galactic Super-Clusters like the Arches or the Quintuplet requires that certain environmental conditions are available. A massive dense clump precursor must be assembled and kept stable against fragmentation long enough to form massive stars, and a mechanism must be provided to trigger the formation of a top-heavy IMF cluster. The 100-pc ring of dense and cold clouds orbiting around the Galactic Center (Molinari et al. 2011) may offer both conditions: it hosts the best candidate for Arches-like precursor (Longmore et al. 2012), as well as the best example of a cloud-collision induced burst of star formation (Sgr B2). To test our hypothesis that the ring is the structure that channels material into high-mass prestellar clumps, we obtained Cycle 3 ALMA 12m-array priority "A" time to carry out a continuum and line survey of the denser clumps (Av > 50 mag) along the 100-pc ring. However, data analysis clearly indicates considerable signal levels from extended components beyond the spatial scale recoverable by the 12m-array. We hereby request ACA observing time for the same target list and instrumental settings to obtain the indispensable short baselines data. | High-mass star formation | ISM and star formation | 2019-04-17T00:00:00.000 |
| 3066 | 2016.1.01548.S | 16 | Imaging Ultra-High-Velocity Molecular Gas in the W44 Supernova Remnant | W44 is a mixed-morphology supernova remnant which is interacting with a giant molecular cloud (GMC). We have mapped the W44 GMC in CO J=3-2 line to analyze the kinematics of shocked molecular gas, and discovered an ultra-high-velocity wing feature, which was named "Bullet". It arises from the W44 GMC, having a velocity width of ~110 km/s. This velocity width is a factor of 5 broader than that of typical wing emission there. It is adjacent to an intense blob of 1.4 GHz continuum and a nebulosity of H2 2.12 micron ro-vibrational line emission. In order to investigate the nature and origin of this anomalously broad-velocity-width feature, we propose high-resolution CO J=3-2 imaging of the Bullet with ALMA. The huge kinetic energy of the Bullet, as well as its compact apperarance indicates that it has been accelerated by a certain local activity which was triggered by a passage of a SN blast wave. High-quality ALMA data will be combined with the single-dish data in stock to obtain high-fidelity images of shock probes. Such images will provide essential information to understand this peculiar object which could belong to a heretofore unrecognized population. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-05-28T00:00:00.000 |
| 3067 | 2016.1.01176.V | 0 | Looking into the throat of the magnetized gamma-ray Blazar 3C279 | 3C 279 is a nearby bright and highly magnetized gamma-ray emitting blazar, whose jet is inclined at an extremely small viewing angle. Previous 1mm EHT studies suffered from too limited uv-coverage, which prevented detailed VLBI imaging. Owing to its strong polarization, large black hole mass, high Doppler-factor and distance, 3C 279 is *a* prime target at 1mm for polarimetry and to test magnetic jet launching in a Quasar, opposed to the less polarized radio-galaxies. At the redshift of 3C279 opacity and Faraday-depth are further reduced (rest-frame frequency: ~352 GHz). Thus we are proposing sub-mm VLBI polarimetry! Here we ak for Band 6 (1.3mm, 230 GHz) VLBI imaging by looking into the optically thin jet-nozzle with a - for quasars - unprecedented resolution of ~150 Schwarzschild radii. The VLBI imaging will resolve the jet also transversely and will reveal its polarized fine-structure. Such high-spatial-resolution polarization information is urgently needed to limit the physical parameter range for state-of-the art GRMHD simulations of BH driven jet launching and for the study of the initial recollimation shock, which is a hot candidate for high energy particle acceleration. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-10-20T16:14:52.000 |
| 3068 | 2018.1.00591.S | 26 | Rotation Kinematics of the V380 Ori NE Protostar-Jet System | We propose to investigate the rotation kinematics of the V380 Ori NE protostellar system by observing the jet in the SiO 2-1 line and the central region in the C18O/13CO 2-1 lines. The angular momentum redistribution is one of the most important processes in star formation. Jets are launched from accretion disks and must be rotating, to transport angular momentum away. If the disk is in a binary system, the tidal interaction can also transport angular momentum, and the jet from a misaligned system may precess. Our VLA observations of V380 Ori NE showed that the SiO jet is well-collimated and precessing, and ALMA is capable of revealing the jet-precession mechanism. We will measure the rotation kinematics of the jet and the central objects to understand the jet-launching and the jet-precession mechanisms. Here we propose to observe V380 Ori NE (1) to study how the jet rotates, (2) to understand the jet-disk connection and constrain jet-launching models, (3) to determine the relative sense of precession and constrain the jet-precession models, (4) to verify the consistency between the kinematics of the jet and the circumstellar/circumbinary structure. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2021-02-07T11:39:56.000 |
| 3069 | 2011.0.00006.E | 0 | VY CMa Band 9 B2B | ALMA engineering data release. | 2018-07-10T12:50:54.000 | ||
| 3070 | 2017.1.00023.S | 89 | Understanding the role of infrared radiative pumping in ultraluminous infrared galaxies | We propose to obtain the molecular line data of (1) HCN/HCO+/HNC J=2-1, (2) vibrationally excited (v2=1f) J=2-1 and J=8-7 of HCN/HCO+/HNC, and (3) their isotopologue H13CN/H13CO+/HN13C, of the ultraluminous infrared galaxy (ULIRG), IRAS 20551-4250. This ULIRG contains a luminous obscured AGN and shows clearly detectable v2=1f J=3-2 and J=4-3 emission lines of HCN and HNC in our previously taken ALMA data, thanks to small observed molecular line widths. Thus, this ULIRG is an excellent laboratory to estimate how the infrared radiative pumping mechanism affects the observed HCN/HCO+/HNC rotational J-transition fluxes, in addition to the widely assumed collisional excitation. By combining with our previously taken ALMA data for this ULIRG, we will first constrain molecular gas physical properties, and then evaluate how the infrared radiative pumping contributes. Our comprehensive (sub)millimeter molecular line data set of IRAS 20551-4250 will be an invaluable basis to understand the physical origin of the observed (sub)millimeter molecular line flux ratios in AGN-containing ULIRGs from the local to distant universe, whose ALMA observations will routinely be made in the near future. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2019-10-03T07:16:12.000 |
| 3071 | 2015.1.01015.S | 20 | Resolving the debris disk and its structure around the young M dwarf TWA 7 | Debris disks can be seen as the left-overs of giant planet formation and the possible nurseries of rocky planets. While M-type stars out-number more massive stars we know very little about the time evolution of their circumstellar disks at ages older than ~10 Myr. It is unclear whether the scarcity of debris disks around M dwarfs is related to instrumental sensitivity or to dissipation processes that are specific to low mass stars such as stellar winds. Spatially resolved submm observations of the young debris disk around TWA7 may provide new insights on the dynamical evolution of these circumstellar disks as well as on the dust properties (e.g., size distribution, multiple-disk components, as suggested by the SED). Emission lines detected in spectroscopic observations also suggest the presence of winds, making TWA 7 a very interesting target to possibly characterize disk-winds interactions. Variable absorption components detected on top of the chromospheric emission on the CaII H&K lines suggest the presence of some gaseous component/s; either residual left overs of the primordial disk or, some second generation gas originated for example by evaporating bodies. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2017-07-14T14:07:44.000 |
| 3072 | 2012.1.00229.S | 0 | Gas and Dust in the Disk Orbiting BP Piscium | We have recently discovered a new class of dusty, sometimes accreting first-ascent giant star. We dub these objects "Phoenix Giant" stars due to their re-birth into young star-like conditions. Ultimately we desire to identify the source of the dusty and often gaseous circumstellar material now orbiting these giant stars and to search for signs of new planet/planetesimal formation occurring in their disks. Here we propose to observe the remarkable Phoenix Giant star BP Piscium. With ALMA's superior angular resolution and sensitivity we aim to resolve with high fidelity the gas and dust orbiting BP Piscium and examine their spatial distributions, in particular whether or not they are co-spatial. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-05-09T12:09:49.000 |
| 3073 | 2019.1.00328.S | 12 | The phase of CO in the embedded disk around the faintest protostars | We propose to observe C18O, 13CO (2-1) and N2H+ (3-2) emission toward four low-luminosity objects (LLOs, internal luminosity <0.2 Lsun), aiming to find the cold inner disks or disk-like structures with CO freeze out in the midplane. The CO snowline sets the C/O abundance in the gas and ice interior and exterior to itself, affecting the elemental ratio of planet-building material. Because planet formation may start very early, those snowline radii at the Class 0 stage are important for the chemical composition of the planets later formed. However, because of the viscous heating by accretion and the low efficiency of radiative cooling in the inner dense envelope, the early embedded disk would stay warm, preventing CO to freeze out in the majority of the disk. We found a potential cold disk with CO freeze out at the midplane in the LLO IRAS16253 (Hsieh et al. 2019). This suggests that those faintest sources, LLOs, are good condidates that host a cold disk, a unique condition of planet growth. The proposed observations aim to found such a cold disk with CO freeze out at the disk midplane in protostars at embedded phases (Class 0/I) for the first time. | Low-mass star formation | ISM and star formation | 2022-09-10T18:46:31.000 |
| 3074 | 2019.1.01259.S | 6 | Cold gas and dust distributions around a precisely localized AGN in a dust-obscured star-forming disk at z = 1.9 | We propose high-fidelity 0.06-resolution CO(4-3) observations of an Einstein ring of a typical star-forming galaxy (SFG) at z = 1.9. This galaxy is unique because the combination of VLA and PdBI radio and dust continuum observations have pinpointed the location of its AGN by means of a spatially-resolved radio excess in the source plane. The AGN appears to be embedded in an intensely star-forming disk six kpc across. Such a precise knowledge of the AGN position within a galaxy is rare because SFGs at z ~ 2 are commonly heavily obscured by dust. The proposed observations will map the cold gas and dust with ~100 pc resolution. Our goals are to (1) capture the gas surface density from the scales of kpc down to ~100 pc of the MBH to search for the gas density enhancement predicted by the simulations of the self-instability facilitated AGN fueling mechanism; (2) search for (or provide constraint on) the ~100-pc-sized star-forming clumps whose clusters are predicted to have led to the observed kpc-sized star-forming clumps. This substantial investment of ALMA time will pioneer the combination of ALMA and radio observations to study the dust-obscured sub-galactic structure at z ~ 2. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2023-03-01T15:28:55.000 |
| 3075 | 2015.1.00762.S | 11 | The nature and origin of the Solar system scale disk in the Helix Nebula | We intend to image the Solar system scale, dusty disk around the central star of the Helix nebula, the closest planetary nebula (PN, d=152 to 219pc). There are two scenarios for its origin: a Kuiper belt that survived the stellar post-main sequence (post-MS) evolution or a remnant post-Asymptotic Giant Branch (pAGB) disk that formed from material ejected by the star during that phase. We will measure the gas content and probe for large grains in the disk in order to distinguish between the two scenarios. The primordial Kuiper belt case: This will be the first Kuiper belt confirmed and imaged around a star that went through the post-MS evolution and the first direct evidence that planetary systems survive this phase. We will observationally investigate the effects of this phase on planetary/planetesimal systems. The remnant post-AGB disk case: We will measure its gas and dust mass to test predictions of evolutionary time scales of such disks. We will investigate whether second-generation planet(esimal) formation is possible there. Our observations will impact our understanding of the evolution of post-MS stars and their disks and on the binary hypothesis of PN formation. | Debris disks, Exo-planets | Disks and planet formation | 2017-11-09T15:41:12.000 |
| 3076 | 2024.1.01482.S | 0 | Constraining 12C/13C and 16O/18O from direct measurements of 13CO, C18O and 13C18O in the Galactic outer disk | The 12C/13C and 16O/18O abundance ratios provide rich information on physical processes regulating the chemical evolution of stars and galaxies, which shows gradients along the Galactic radii. However, these isotope ratio gradients are poorly constrained at Galactocentric radii (Rgc) beyond 12 kpc. New measurements at Rgc > 12 kpc are urgently needed. Direct derivation of 12C/13C and 16O/18O from 13CO/C18O/13C18O is the most feasible approach in the Galactic outer disk. However, corresponding measurements are quite lacking. With existing data from Cycle 10, we obtained prior results of 12C/13C and 16O/18O from 13CO, C18O, and 13C18O 1-0 in four clouds in the Galactic outer disk, extending these ratios to regions with Rgc ~ 17 kpc. However, the signal-to-noise ratios are insufficient for robustly constraining chemical evolution in the outer disk. Therefore, we propose additional measurements (6.7 hours of 12-m) in these targets to enhance signal quality. The applied observations will put strong constraints on the Galactic chemical evolution in the far-outer disk and aid in examining the potential inhomogeneous mixing of isotopes within the outer regions of the Milky Way. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-10-18T18:49:08.000 |
| 3077 | 2011.0.00419.S | 0 | First images of a protoplanetary disk around a very massive protostar | One of the most important questions in the field of star formation is to test if very massive stars (i.e. stars that will become O-type stars) form by accretion from circumstellar disks (as it is the case for low-mass stars) or if other phenomena are at work. IRAS 16547-4247 is the most massive protostar found associated with collimated jets (with ATCA and the VLA) and a rotating molecular structure (with the SMA) that probably will reveal with higher angular observations as a disk. We propose to undertake ALMA observations of several tracers of dense gas that will test critically the presence of an accretion disk around this source. In particular, we may provide the first evidence of a Keplerian signature (inner parts rotating faster than the outer parts) in a disk associated with a massive forming star. The confirmation of an accretion disk around a massive forming star will not only prove that they form by an analogous mechanism than solar-type stars but it will open the possibility of studying the physical conditions of these disks and to address questions such as if they can form not only planets but brown dwarfs and even stars. As part of the project we will also search for recombination lines from the powerful thermal jet associated with this source. | High-mass star formation, Disks around high-mass stars | ISM and star formation | 2014-03-07T05:23:00.000 |
| 3078 | 2015.1.01439.S | 106 | UNVEILING MERGER-INDUCED SHOCKS IN MOLECULAR HYDROGEN EMITTING GALAXIES (MOHEGs) | Galaxy merger produces large-scale shocks due to the collision between the progenitors gas disks. Since shocks affect icy mantles and/or dust grain cores (e.g., Si), dust-related molecules should be enhanced in the gas phase. Our 3 mm observations with the cycle 0 and 2 ALMA detected one of the shock tracers, CH3OH (2-1), in nearby merging galaxies, NGC 3110 and VV 114. To develop the results, we require multi-transition observations of well-known shock tracers, CH3OH, HNCO, and SiO emission, for the two molecular hydrogen emitting galaxies (MOHEGs), NGC 6240 and IRAS F16399-0937, in order to constrain gas excitation and abundances of dust-related molecules quantitatively in merging galaxies. The targets are selected from the Spitzer/IRS observations of nearby luminous infrared galaxies which show the strong H2 (1-0) S(1) emission. Multi wavelength studies revealed that AGN nuclei in both targets show less contribution to the total IR and emission lines. Therefore, the strong H2 (with strong H and suppressed PAH) may be due to galaxy collisions or radio jet feedback from the nuclei, so that NGC 6240 and IRAS F16399-0937 are ideal for studying merger-induced shocks. | Merging and interacting galaxies, Galaxy chemistry | Galaxy evolution | 2018-04-21T10:34:43.000 |
| 3079 | 2015.1.01577.S | 9 | Probing the in-fall disk in the giant elliptical galaxy NGC 5128 | Please Note: This is a request finish an already-started and mostly completed project. Many large elliptical galaxies contain embedded disks of dust and gas, remnants of a merger with a smaller gas-rich galaxy. The physical properties of such disks, and the resulting initial conditions for star formation are very different from those in disk galaxies and starburst galaxies. We will study these in detail by modelling the molecular gas in the embedded dusty gas disk (``dark band'') of the only nearby giant elliptical, NGC~5128 (Centaurus A). We will apply PDR and radiative-transfer models to the 12CO and 13CO J=1-0 and J=2-1 line transitions in maps of 20 pc resolution over the inner several kpc of the galaxy. We will specifically deduce the gas mass and temperature, for individual clumps and the whole disk as a function of radius, and investigate the relation of the dense molecular gas conditions to the enhanced star formation in the disk. The proximity of NGC 5128 and its present evolutionary stage about halfway between acquisition and final consumption of a gas-rich galaxy provide a unique opportunity to study an advanced merger state in detail. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2017-05-20T20:59:58.000 |
| 3080 | 2017.1.00834.S | 2 | Testing azimuthal dust trapping in transition disks: grain size constraints from polarization | Recent studies have shown that self-scattering by thermal dust emission can produce detectable millimeter-wave polarization in protoplanetary disks. As the efficiency of the scattering and thus the strength of the induced polarization signal depends on the grain size, polarization observations are an alternative method besides the spectral index to constrain the dust particle size in disks. We propose a multi-wavelength polarimetric imaging study toward the inclined and asymmetric transition disk of IRS 48, an ideal laboratory for understanding dust growth and the earliest stages of planet formation. We want to test the theory of azimuthal dust trapping connected with vortices, indicated by previous ALMA observations. The peanut-shaped region around the peak of the dust continuum is where we aim to detect the polarized emission from dust scattering where grains grown to a few hundred microns are expected. The proposed dual-band observation in Bands 7 and 4 will also provide insights about the origin of dust polarization. It allows us to disentangle the polarization mechanisms due to scattering and grain alignment with magnetic or radiation fields. | Disks around low-mass stars | Disks and planet formation | 2019-10-08T18:07:47.000 |
| 3081 | 2019.1.01681.S | 117 | An Efficient Test of Evolved Planetary System Modeling | Atmospheric metals in white dwarf stars are now firmly linked to (disrupted) planetesimal debris, thus indicating that outer planetary systems routinely survive the myriad transformations of their host stars and remain dynamically active. These evolved planetary systems offer a unique and powerful window onto planet formation, by providing bulk compositions for minor (and possibly major) planets, as the element-to-element ratios of the tidally destroyed and accreted bodies can be observed directly in the stellar atmosphere. However, it is not yet known from where exactly these planetary bodies originate. We have constructed a full-lifetime evolutionary model for planetesimal belts, supporting the long-term survival of a mass reservoir sufficient to account for the observed pollution, and favorable to detection with ALMA. We propose to test this model with an efficient Band 6 survey of 20 nearby and luminous white dwarfs, by detecting the cold dust from outlying debris disks. Any detection would revolutionize the field, and has the potential to yield the first resolved image of a planetary system in the post-main sequence. | Debris disks | Disks and planet formation | 2021-04-09T16:41:54.000 |
| 3082 | 2015.1.00504.S | 542 | A search for the most distant and extreme starbursts in the Universe | In Cycle 0 and 1 we performed unbiased redshift surveys in the 3mm band of 39 sources from the SPT sample. These programs were great successes yielding 31 secure redshifts and 5 single line detections. The galaxies in our sample have a mean redshift of z~3.5 with the record holder at z=5.8. The high mean redshift compared to other samples is mainly due to the unique selection wavelength of 1.4mm of the SPT survey and the aid of strong lensing. We use the unique redshift selection function of the SPT sample to identify the most distant and extreme dusty starbursts in the Universe and propose to obtain redshifts (via scans of the 3mm band) and lens magnifications (via high-spatial-resolution 870micron continuum imaging) for the 8 reddest (and thus likely most distant) sources from the SPT sample. With only a 15% increase of observing time we will cover 19 more SPT sources in the same observing setup located in the same fields. With this data we will probe the frequency of occurrence of massive starbursts at extreme redshifts (z=5-7) which will put tight constraints on semi-analytic galaxy formation models and nearly double the number of SPT sources with redshifts and lens models. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-02-18T12:56:56.000 |
| 3083 | 2018.1.00424.S | 2237 | Understanding the chemical complexity in massive star-forming regions | High-mass star-forming (HMSF) regions reveal rich physics and chemical complexity. We propose to perform a deep chemical survey in Band 3 by targeting 36 molecular lines in 12 HMSF regions at different evolutionary stages: infrared dark clouds, high-mass protostellar objects, hot molecular cores, and ultra-compact HII regions. We request a high angular resolution of 1" in order to observe the large-scale fragmentation, and map the chemical segregation and heterogeneities between various molecules and objects. We carefully chose molecules probing high and low temperatures and densities, photochemistry, shocks, accretion, and outflows. In addition, the suite of chosen species enables us to probe the C-, N-, O-, and S-chemistry by targeting many key molecules from these chemical families. We will employ our advanced data analysis and chemical modeling tools to constrain the chemical complexity and diversity across the evolutionary sequence of HMSF regions. | Outflows, jets and ionized winds | ISM and star formation | 2020-08-26T16:53:09.000 |
| 3084 | 2022.1.01570.S | 1596 | An ACA census of molecular clouds across the Galactic disk | A molecular cloud (MC) is sub-virial when the self-gravity dominates over the turbulence and its virial parameter (alpha_vir) is below the equilibrium. We recently find that the MCs in the Galactic outer disk are mostly sub-virial and the alpha_vir decreases with the Galactic radius (R_gc), as expected by the decreasing Galactic mid-plane pressure. However, the alpha_vir could be biased observationally. Previous Galactic works are limited either by the angular resolution or the column density tracers, which bring in great uncertainties when measuring the cloud physical quantities. Up to now, we still lack a complete picture of how the turbulence levels and virial states of MCs are differentiated between the inner and outer Galaxy. In this proposal, we aim to do a census of molecular gas (mainly traced by 13CO J=1-0) toward a sample of MCs across the Galactic disk with ACA to improve the sample size and the angular resolution. We will also compare the Galactic MCs with those in the LMC/SMC. We will show how the dynamic properties of MCs vary with the environment (e.g., external pressure, metallicity, etc.) and the influences on star formation in galaxies. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-09-08T12:27:30.000 |
| 3085 | 2013.1.01301.S | 6 | Multiplicy at the earliest stages of star formation | Observations of populations of T Tauri stars have demonstrated that stellar multiplicity is established very early in stellar evolution and it is likely to be linked to the star formation process itself. High-resolution imaging surveys have recently discovered the existence of brown dwarfs to planetary mass companions at large distances from their parent star (>100AU) in nearby star-forming regions, increasing the general interest for understanding the formation of multiple systems. Nevertheless, multiplicity at the early phases of the star formation is still poorly characterized due to the poor sensitivity and spatial resolution of old telescopes to detect dust and molecular gas surrounding the companions. In order to determine the initial conditions of the formation of multiple systems and to identify the dominant physical scales that govern those mechanisms we propose to observe a sample of southern Bok globules to study multiplicity to the limit of planetary-mass (<1Mjup) at the earliest stages, in an ideal isolated and simple environment. This will help us to test if core prompt fragmentation is the leading candidate scenario to form multiple systems. | Low-mass star formation | ISM and star formation | 2016-11-25T05:27:18.000 |
| 3086 | 2018.1.01288.S | 7 | Studies of disk+outflow systems in high-mass star formation with KaVA and ALMA | We propose a survey of high-mass young stellar objects (HM-YSOs) associated with the 22 GHz H2O masers to investigate physical properties of their disk+outflow systems. We have been conducting monitoring observations of the 22 GHz H2O masers toward 17 HM-YSOs to investigate 3D velocity structures of outflows in the KaVA (KVN and VERA Array) Large Program. In the proposed ALMA Band 6 observations, we will identify powering sources of outflows traced by the 22 GHz H2O masers and obtain their physical properties using dust continuum. In addition, we will observe molecular lines to reveal spatial and velocity structures. Thermal lines of CH3OH and HCOOCH3, and 213 GHz class II CH3OH maser trace disks, while thermal SiO and 229 GHz class I CH3OH masers probe outflows. They will be used to fill the gap between central HM-YSOs and maser distributions emitted in the outflows. We can derive physical parameters such as dynamical time scale, mass loss rate, mass accretion rate, etc, by combining the KaVA proper motion measurements. These comprehensive studies will be compared with theoretical models to understand mass accretion through disks, mass ejection, and feedback to the ambient gas. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2021-01-24T17:32:18.000 |
| 3087 | 2016.1.01126.S | 41 | Gas Supply and Quenching of Post-Starburst Galaxies at z~0.6 | Below a redshift of z~1, the massive end of the galaxy population is dominated by elliptical galaxies with quiescent stellar populations. Despite many investigations, the question of why these galaxies stopped forming stars remains subject to much debate. We propose to constrain the physical processes responsible for the suppression of star formation by observing the molecular gas content in a sample of recently quenched post-starburst galaxies at z~0.6. The stellar light of these post-starburst galaxies is dominated by A-type stars, and thus they have likely just experienced their initial quenching phase. Using the molecular gas content and kinematic properties, in combination with hydrodynamic galaxy formation simulations, this study will provide new insight into why galaxies enter their quiescent phase. This study is a pilot program and will pave the way for ALMA studies of larger and/or more distant post-starburst galaxy samples in the coming years. | Galaxy structure & evolution | Galaxy evolution | 2019-01-18T22:10:15.000 |
| 3088 | 2017.1.01339.V | 0 | Probing the polarized innermost structure of the relativistic jet of 4C +01.28 | We want to probe the polarized fine structure of the nuclear region of the blazar 4C +01.28 (B1055+018, J1058+015) via 1.3-mm EHT+ALMA observations. 4C +01.28 has a mm flux density over 3 Jy, highly variable up to high energies. Recent GMVA 3-mm results show a compact polarized core with a faint relativistic jet. It is an excellent target for ALMA with high brigtness at the celestial equator. At cm-wavelengths, its polarized structure consists of a two-component structure, with an inner spine with a transverse B field and a distinct boundary layer (the sheath) with a longitudinal B field. Our observations will provide a deep polarization image of the stratified jet at ~30uas resolution, probing uniquely whether the spine-sheath structure extends to jet base and testing, on scales of 1200 R_s, the different MHD jet formation models: Blandford-Payne models, where the jet is anchored to magnetized rotating disks, should result in an edge-brightened polarisation up to the base of the jet; or Blandford-Znajek models, where the jet is driven by the BH spin, result in a more compact footprint of the jet, which implies a higher opacity and a smaller polarisation degree. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 3089 | 2018.1.01198.S | 67 | Dust Trapping in the Substructures of Protoplanetary Disks | Substructure in protoplanetary disks is fundamental to allow the transformation of disk material into planetary systems. Theory predicts that without substructure in the gaseous disk component, large solids are lost due to radial drift, impeding planetesimal and planet formation. If disk inhomogeneities exist, they create localized pressure enhancements that can effectively trap drifting solids, evolving the particle-size distribution to include large grains. This idea can be tested observationally, by spatially constraining the distribution of solids of different size at high spatial resolution. We recently carried out an ALMA Large Program at 1.3mm to study substructure in 20 protoplanetary disks, constraining the spatial distribution of ~1mm particles down to 3AU scales and revealing a multitude of features in these disks. Here we propose ALMA 3 mm observations with matched spatial resolution and sensitivity for the 8 bright disks that can be readily observed at 3mm. This program will probe particles 3 times larger in size, allowing us to constrain the particle-size distribution in ~6-9AU scales, and test if particle trapping occurs in the small-scale substructure. | Disks around low-mass stars | Disks and planet formation | 2021-10-19T00:00:00.000 |
| 3090 | 2021.1.00172.L | 1031 | ACES: The ALMA CMZ Exploration Survey | The extreme environment and relative proximity to Earth make the centre of our Galaxy a unique astrophysical laboratory. The gas properties, radiation field, cosmic ray ionisation rate, etc., are more similar to those in the centre of other galaxies, starbursts and high-z galaxies than the Solar neighbourhood. It is the only such extreme environment in which it is possible to resolve down to size scales of individual forming stars and link the small-scale physics of star formation and feedback with the galactic-scale processes that together drive the evolution of galaxies. We propose to use ALMA's revolutionary combination of sensitivity, resolution and image fidelity to exploit this laboratory. The ``ALMA Central Molecular Zone Exploration Survey" (ACES) will derive the gas properties from cloud scales down to the size scale of individual forming stars across the inner 100pc of the Galaxy. This will address fundamental open questions in star formation and galaxy formation/evolution, providing a new benchmark for understanding how the mass flows and energy cycles shape the centres of galaxies, regulate star formation and control the activity of the central supermassive black holes. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-06-07T00:00:00.000 |
| 3091 | 2022.1.00367.S | 9 | Supersonic Expansion of the Young HII Region S106: Fossil Bipolar Outflow or Protostellar Explosion? | ALMA Band 3 and 6 mosaics of S106 covering a 100" by 200" field in the continuum, radio recombination lines, and molecular transitions will illuminate the last stages of accretion onto a massive protostar and its transformation into a main-sequence object. Located at a distance of 1.09 kpc, S106 is the youngest optically visible HII region in the Solar vicinity. Unlike other HII regions, the surrounding nebula expands supersonically with speeds up to 170 km/s, indicating either a wind-driven nebula, the recently ionized interior of a fossil bipolar outflow, or an explosion about 3,500 years ago. ALMA will determine the nature of the expansion. Its central ~20 Solar mass O-type binary star, S106IR, is surrounded by an edge-on disk and massive envelope, yet it ionizes the twin lobes of a bipolar HII region. Because of its fortuitous orientation, proximity, and youth, an ALMA study of S106 will shed new light on the last phases of stellar growth of a forming O-star, the emergence of a massive star from its birth environments, and feedback mechanisms in the self-regulation of star formation when a massive star is born. | High-mass star formation, HII regions | ISM and star formation | 2024-10-03T13:10:09.000 |
| 3092 | 2018.1.00618.S | 2 | Polarization of the GG Tau A dust ring | Recent ALMA observations of the continuum polarization in HD 142527 have demonstrated that dust self-scattering at millimeter wavelengths can be important in disks. Due to the large (~100 au in radius) central cavity, dust grains on the dust ring of HD 142527 produce anisotropic self-scattering and thus cause a flip in the position angle of polarization across the dust ring along radius. The degree of polarization is, however, more complex than the predictions from a simple self-scattering model. Spatially resolved and multi-wavelength observations of the polarization are a new powerful tool to constrain the grain size distribution in protoplanetary disks. Contrary to HD 142527, GG Tau A is surrounded by a uniform ring, where the width extends from 180 to 260 au in radius. This makes GG Tau A system a relatively clean target to test the origin of polarization at mm/submm, to study the distribution of grain size and to study any underlying sub-features. We propose here to observe the dust disk surrounding GG Tau A at the resolution of 0.3" in band 7 and 0.6" in band 3 in polarization. | Disks around low-mass stars | Disks and planet formation | 2020-01-23T07:04:50.000 |
| 3093 | 2023.1.00578.S | 0 | Estimating Dust Grain Sizes in the HD 163296 Disk using Band 9 Observations as a Temperature Probe | Dust growth in protoplanetary disks is a central issue in planet formation, and therefore observational constraints on the dust size in protoplanetary disks can be a key to unraveling the planet formation process. However, observational constraints on dust size are challenging. Dust size, dust surface density, and dust temperature are typically estimated from multi-wavelength observations, but the degeneracy of these parameters makes the estimation difficult. In this proposal, we aim to make a reliable estimate of the dust size in the HD 163296 disk, using ALMA Band 9 (0.45 mm) observations as a temperature probe. The deviation of the Planck function from the Rayleigh-Jeans approximation at higher frequencies allows for a more accurate temperature estimate, as small temperature differences result in large intensity variations. With these improved temperature estimates, we can place better constraints on dust size and surface density by resolving the degeneracy. Our proposed observations will provide insight into the dust growth processes in Class II disks and advance our understanding of dust evolution and planet formation within disks. | Disks around low-mass stars | Disks and planet formation | 2025-07-11T16:34:19.000 |
| 3094 | 2017.1.00558.S | 17 | Probing the dust nucleation zone around the Red Supergiant VY CMa | The mass ejection from evolved stars rules the final stages of their evolution and is essential for the chemical evolution of the Galaxy. This mass ejections are known to be driven by the momentum transfer from the dust to the gas. This dust is formed around the star and is itself accelerated by radiation pressure. However, while the dust formation for C-rich evolved stars is known to be based on carbon clusters, it is quite unknown for O-rich stars. We aim to map the innermost regions of the O-rich Red Supergiant VY CMa where the dust is being formed to trace the species arising and fading in these regions, and its relation with the dust formation. In particular, we have selected a spectral setup rich in narrow lines, i.e. from gas still being accelerated in regions where the gas is being formed, as well as in species with strong refractory characteristics as SiO, TiO2 or NaCl. Those refractory materials are expected to be rapidly depleted into grains and only reappear if evaporated from them. These observations could shed light to the dust formation processes, provide inputs to dust-growth laboratory experiments and identify species related to the dust-gas chemistry. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2019-02-21T16:41:55.000 |
| 3095 | 2012.1.00366.S | 39 | Fragmentation of massive dense clumps: unveiling the initial conditions of high-mass star formation | High-mass stars are born from the gravitational collapse of massive dense clumps, and the way they form dramatically depends on how the parent clump fragments into cores during collapse: either via competitive accretion in highly fragmented clumps, or through accretion onto single cores if clump fragmentation is suppressed. Simulations of the collapse of massive, turbulent and magnetised clumps show that fragmentation is efficiently inhibited by a strong magnetic support, while if the magnetic field is faint, turbulence dominates and a lot of fragments are expected. To make a substantial progress in this debate and understand which physical mechanism (turbulence or magnetic field?) sets the initial conditions of the high-mass star formation process, we propose to derive the core population (mass, number and distribution of fragments) and the core kinematics in 11 massive millimeter clumps, undetected in the MSX bands. None of the clumps show evidence of on-going star formation and all have the potential (mass and surface density) to form high-mass stars. Moreover, large CO depletion factors have been measured in all clumps: this represents strong chemical evidence that they are either starless or so young that the possibly embedded protostars have not affected the environment yet. Core population and kinematics will be derived by observing the sub-mm continuum at ~280 GHz and the N2H+(3-2) rotational transition (both already detected in all clumps with single-dishes) down to linear scales comparable to the core separation predicted by the simulations (~1000 AU). If the magnetic field dominates the fragmentation process, we expect to find one (or few) fragments surrounded by an envelope stable against further fragmentation in most of the clumps; if turbulence dominates, a majority of highly fragmented clumps is foreseen. | High-mass star formation | ISM and star formation | 2016-11-15T14:07:46.000 |
| 3096 | 2016.1.00344.S | 88 | Detecting the kinematical signature of accreting protoplanets with ALMA long baselines | Witnessing the formation process of a planet is a foremost ALMA Science Driver and we propose to accomplish it by detecting the distinc kinematical signatures of the circumplanetary disks (CPD) feeding accretion onto the two most promising protoplanet candidates: HD100546b and HD169142b. These protoplanets/CPDs have eluded detection in continuum, and their identification demands predictions on CPD gas tracers. With breakthrough angular resolutions, and informed by state-of-the-art 3D numerical simulations, our predictions show that deviations in the Keplerian pattern provoked by CPD kinematics are detectable with ALMA Cycle-4 in Band-6 with CO isotopologues at the highest resolution offered (30mas). We assessed the feasibility of these observations by corrupting our CPD simulations with realistic phase noise and uv coverage extracted from the HL Tau long baseline campaign. The detection (or lack thereof) of the most prominent protoplanet candidates will constrain CPD hydrodynamics and planet formation theories by measuring the size of the CPDs and provide the first dynamical measurement of a protoplanets mass. This effort requires 11 hrs in total - excellent uv coverage is crucial. | Disks around high-mass stars | Disks and planet formation | 2018-11-30T15:08:47.000 |
| 3097 | 2023.1.00394.S | 0 | Multi-frequency Observation of a Forming Massive Binary | The inital status of massive binaries during their formation while they are still highly embedded and accreting are still unclear. We propose ALMA Band 7, 8, 9 and 10 continuum and line observations to probe the circumstellar disks and circumbinary disk of IRAS 07299-1651, which is a massive protobinary system with a separation of 180 au. The multi-band high-frequency observation will allow us to constrain the dust emission in the circumstellar disks. With such dust component constrained, we can better estimate the free-free emission in the existing 1.3 mm to 1.3 cm continuum data, to constrain the stellar properties. The proposed observations will probe the binary orbital motion via proper motion and hydrogen recombination line kinematics, to constrain the dynamics of this forming massive binary. The proposed observations will probe the spatial substructure inside the circumbinary disk, including its connections to the smaller circumstellar disks and the larger infalling streams. Such observations will provide the full picture of this forming massive binary on multiple scales to present an important case study of massive binary formation. | High-mass star formation | ISM and star formation | 2024-11-17T17:19:23.000 |
| 3098 | 2017.1.00318.S | 25 | A Resolved Measurement of the (Break of) HCN, H_2, and Star Formation Relations in a Local Starburst Environment | Galaxies follow several scaling `laws' between the amount of star formation and its available fuel. Samples of luminous Galactic clumps follow the extragalactic Gao-Solomon relation between HCN (proxy for the amount of dense gas) and bolometric luminosity (star formation rate). These clumps are key because they dominate the star-formation rate of our Galaxy, and presumably correspond to the typical environments in vigorous star-forming galaxies and starbursts. We propose for the first resolved measurement of scaling laws between HCN, H2 and star formation rate in one of the most luminous star-forming clumps in the Milky Way (W49N, Lbol>10^7 Lsun), including two J-transitions and isotopologues to disentangle optical depth and excitation effects. Our single-dish measurements show that the extragalactic relations are valid in this environment at clump scales. The ALMA data will serve to measure at which scale these relations break, somewhere between the scale of the full clump (6 pc) and of star forming cores (0.1 pc). The results will give important insight on the possible origin of extragalactic star formation relations as the outcome of physics within cluster forming clumps. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-12-07T21:22:54.000 |
| 3099 | 2021.1.01322.S | 44 | Inheritance or reset? Probing accretion shocks with SO and SO2 | Is the gas and ice composition in the planet(esimal) formation zone of disks largely inherited from the pre-stellar core or has it been reset? One of the biggest uncertainties in answering this question is knowing whether or not the material undergoes a strong accretion shock as it enters the disk. High-resolution (~20-30 AU) ALMA images can potentially trace this shock and distinguish it from disk winds or jets/outflows through observations of suitable molecular tracers. SO and SO2 are two particularly well-suited molecules since their emission has been observed to originate at the disk-envelope interface and they are known shock tracers. We here propose to image both molecules in multiple lines (to constrain excitation) using a single ALMA Band 6 setting at much higher spatial resolution (~0.15") than done previously for the case of SO, to search for evidence of accretion shocks that reset the gas and ice chemistry. Combination with approved VLT-MUSE and future JWST-MIRI GTO and ERS data will help to further pin down the physical and chemical processes at the envelope-disk-outflow interface. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-12-22T23:57:26.000 |
| 3100 | 2013.1.00308.S | 12 | Gas temperature and kinematics as key inputs for star formation theory: Cores and turbulence in the massive protocluster W51 | We propose to image the temperature and velocity structure and measure the upper end of the core mass function within a massive cluster forming cloud, W51. We will use the p-H2CO lines at 218 GHz to map the gas temperature and 1.3 mm dust continuum emission to map the cores. The CO 2-1 line will be used to firmly identify the accreting cores by their outflows. These observations will be the first parsec-scale, high-resolution temperature maps of a forming massive cluster and will include the first measurement of the high-mass end of the core mass function in a region where it is expected to be fully sampled. The selection of p-H2CO as the thermometer is essential for determining the effect of gas temperature on star formation as it avoids a chemical bias towards already-fragmented gas that affects other gas thermometers. This project will provide a test of current star formation theories. We will measure the theoretical inputs to these theories, in particular the local Mach number and the gas temperature distribution, and the as-yet unconstrained high-mass end of the core mass function. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-07-03T22:39:25.000 |
| 3101 | 2012.1.00193.S | 2 | Measuring the Mass of the Class 0 Protostar L1527 via Disk Rotation | The masses of protostars in the earliest phase of protostellar evolution are extremely uncertain, but are key to our understanding of the mass accretion process and the timescales on which it must take place. We recently detected a rotation signature in the resolved disk (R ~150 AU) of the Class 0 protostar L1527 in Taurus using the 13CO (J=2-1) transition, enabling us to weakly constrain the protostellar mass to be ~0.125 solar masses. This is about an order of magnitude less than the envelope mass. While this result is extremely important, it is not accurate enough to provide constraints for protostellar evolution or mass accretion models. We propose ALMA observations of the H13CO+ (J=3-2) line toward L1527 in order to determine the mass of the central protostar with an uncertainty better than 25\%. These data will also enable us to verify that the disk rotation is Keplerian at all radii; this is a crucial aspect to verify before confronting theory. It is critical to understand how much mass protostars have in the earliest phases of evolution to determine how quickly they must accumulate their mass between the Class 0 and I phases. We will be able to directly compare L1527 to models of disk formation which have specific predictions for protostellar mass and disk mass at a give time. Moreover, the mass of the protostar enables us to determine how much luminosity is from the protostar and how much is from accretion, yielding an estimate of mass accretion rate. Dust continuum emission will be simultaneously probed at 1.1 mm, providing constraints on the disk mass and radius superior to the current data. | Low-mass star formation | ISM and star formation | 2016-11-13T02:38:58.000 |
| 3102 | 2017.A.00030.S | 14 | First radioactive molecule observed in space: 26AlF in a stellar-merger remnant | Using ALMA and NOEMA arrays, we detected, for the first time, an isotopologue of AlF that contains the radioactive isotope of 26Al, with a mean life-time of 1.04 Myr. This isotope has been observed earlier in the Galaxy only through its gamma-ray decay line at 1.8 MeV. However, owing to poor angular resolution and insufficient sensitivity of the gamma-ray observatories, sources of the 26Al have never been directly identified. Our observation of the radioactive molecule may constitute a stepping stone to identifying more Galactic sources of this isotope and shed more light on the Galactic nucleosynthesis. Our observation, reveals also new details about the eruption that took place in 1670 in Nova 1670 (a.k.a. CK Vul), where 26AlF was detected. Although, in our opinion, the evidence for the first detection of 26AlF is very strong, reviewers and editors of our 26AlF study require more evidence. Here, we ask to obtain an ALMA observation of a fourth transition of 26AlF, J=6-5, near 200.954 GHz. | Evolved stars - Chemistry | Stars and stellar evolution | 2018-10-25T02:21:34.000 |
| 3103 | 2023.1.01139.V | 0 | A sample of SMBH shadows, rings, accretion flows and jet bases: exploratory EHT+ALMA flux measurements | The photon rings around the supermassive black holes (SMBH) in M87 (10^9 Msun, powerful jet) and SgrA* (10^6 Msun, no/weak jet) have been imaged with the Event Horizon Telescope (EHT). Here we request EHT+ALMA 230GHz nuclear flux measurements of 15 SMBHs, in order to complete characterization of all ~35 SMBHs with bright > 43 GHz VLBI detections and which can be imaged at <1000 gravitational radius resolution with the EHT+ALMA. UV analysis of these snapshot observations will immediately constrain jet base brightness and morphology, constrain the flux from an accretion flow, and perhaps SMBH mass. Our larger goal is to identify all sources in which near-future deep EHT+ALMA imaging can: (a) resolve the jet base thus providing constraints to jet launching theory over varying mass, spin, accretion rate, jet orientation and power; (b) resolve accretion flows and orbiting hotspots, providing constraints to accretion theory; and (c) identify SMBHs whose SMBH photon rings or shadows can be resolved using existing super-resolution techniques, thus providing constraints to gravity theories. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 3104 | 2015.1.01187.S | 3 | ALMA observation of a galaxy cluster merger shock at half the age of the universe | We propose to observe a prominent radio relic in the massive galaxy cluster ACT-CL/SPT-CL J0102-4915 ("El Gordo") with ALMA at 100 GHz, to detect the signature of a merger shock using the Sunyaev-Zel'dovich (SZ) effect. At z=0.87 this is one of the most massive clusters known, with extensive optical, X-ray and SZ observations. The detection of a pressure discontinuity with ALMA will be the highest redshift observation of a large-scale astrophysical shock, when the universe was only half of its present age. Both positive and negative detection will have important consequence for our understanding of the origin of radio relics as well as growth of clusters through mergers. We have based our shock model on all the available SZ, X-ray and radio data, predicting a shock signature that can be detected by the ALMA 12m array at roughly 5 sigma significance in 3.5 hours of integration. The 7m compact array will provide effective short spacing information, detecting the shock feature at more than 10 sigma and significantly enhancing the constraining power on our shock model parameters. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2017-10-20T17:22:39.000 |
| 3105 | 2011.0.00229.S | 0 | A STUDY OF THE DUST FORMATION ZONE IN IRC+10216 | We propose to observe the J=3-2 and J=8-7 lines of HCN in all its vibrational states below 15000 K using the longest baselines provided by ALMA early science. These transitions of HCN will trace the physical conditions of the dust formation zone, corresponding to 5 | Evolved stars - Chemistry, Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2015-02-12T13:51:45.000 |
| 3106 | 2018.1.01871.S | 305 | The [CI]/dust relationship in star forming galaxies at redshifts 1-2 | Almost all high-redshift gas measurements to date rely on CO as a tracer, but this is plagued by systematic uncertainties due to optically thick emission and poorly constrained dependencies on gas density, distribution and metallicity, as well as the difficulty of observing low-excitation CO lines. Dust continuum shows some promise as a high-z gas tracer via the dust/gas ratio, and needs calibrationon a direct gas tracer at z>1. We therefore propose to measure the [CI]/dust continuum relation in a sample of massive galaxies at 0.8 < z < 2.5 detected at 850m. We will build on the results of a successful pilot study at z 1 (PI: N. Bourne; 2016.1.01184.S, 2017.A.00013.S) by observing a larger sample which extends over a wider range of redshifts and higher stellar masses. We will determine whether there is a universal [Ci]/continuum ratio for galaxies on the main sequence, and whether galaxies with either higher star formation rates (SFR) or higher specific SFRs deviate from this. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2020-07-02T14:04:26.000 |
| 3107 | 2012.1.00993.S | 1 | Determining the Nature of the mm Radio Emission from Active M Dwarfs | Quiescent radio emission from active stars in the 1-15 GHz frequency range was discovered in the early days of the VLA. Recent observations with the newly upgraded Jansky VLA have now confirmed the detection of a new, brighter, high frequency component (20-40 GHz) in the radio emission from two main sequence active M dwarfs that is stably present in multiple epochs. Determining the nature of this emission is crucial if the diagnostic potential of this new observing window is to be realized. One of these stars is the well characterized flare star UV Ceti. We propose to use ALMA to conduct a single 45 minute observation of UV Ceti to conclusively distinguish between gyroresonance emission and gyrosynchrotron emission as the mechanism responsible for this emission. This observation may open the possibility of extensive ALMA campaigns targeting the coronae of active stars. | Main sequence stars | Stars and stellar evolution | 2015-12-05T12:23:16.000 |
| 3108 | 2017.1.01116.S | 477 | High Resolution Imaging of Inflow & Infall in Massive Star-forming Clumps | Recent observations have begun to study massive clumps with global gas inflow rates as high as 1000 Msun/Myr. This inflow affects the evolution of dense cores and may be necessary for the formation of massive stars; however, observational constraints on the nature of the kinematic motions (i.e. core accretion through filaments or more spherical inflow) are still sparse. Using the 10m SMT, 6194 dense massive clumps from the Bolocam Galactic Plane Survey (BGPS) were observed in HCO+ 3-2. A subsample of 45 clumps were identified with well defined blue-assymetric line profiles in HCO+ (Shirley et al. 2013). These sources are the best massive inflow/infall clump candidates in the first quadrant of the Galaxy for which the geometry and excitation conditions are most favorable to study the inflow/infall kinematics at high resolution. We propose observations at 3 mm in the infall tracers HCO+ 1-0, HCN 1-0, and CS 2-1 as well as dust continuum at 1.25 mm to study the kinematics and fragmentation of a subsample of the 8 best massive (400 < M < 3200 Msun) inflow candidates within 6 kpc identified in the BGPS. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2019-04-02T13:42:25.000 |
| 3109 | 2015.1.00253.S | 12 | Search for the 12CO(4-3) and 12CO(3-2) lines of dusty star-forming galaxies at z=2.23 protocluster | We search for 12CO(4-3) and 12CO(3-2) lines of 6 dusty star-forming galaxies in the 2QZ cluster at z=2.23 with ALMA band 4 and band 3. In Matsuda et al. (2011) we discovered the amazing large-scale structure of Ha emitters (HAEs) associated with the concentration of 4 bright QSOs on its peak (the ``2QZ'' cluster). Recently we have further identified a strong concentration of the Herschel/SPIRE sources just adjacent to the HAE density peak. Something must be going on near the HAEs density peak of 2QZ cluster, suggesting this protocluster could be experiencing both dusty enhanced star-formation and AGN activities compared with field environment at the same epoch. However, because the SPIRE color selection has a redshift uncertainty, we require spectroscopic observations. This proposal allows us to confirm the dusty enhanced star-formation activities (several 1000 M_sun/yr) with its z=0 cluster halo mass > 10^15 M_sun and the quantities of molecular gas contents. | Starburst galaxies | Active galaxies | 2017-09-07T07:09:51.000 |
| 3110 | 2021.1.00874.S | 8 | Star Formation and the Turbulent Interstellar Medium of Lyman Break Galaxy Analogs | A major challenge for studies of galaxy evolution is understanding the details of star formation in key populations at all redshifts. While Lyman break galaxies (LBGs) at z>3 have been studied extensively, their dense gas reservoirs remain poorly understood due to limited sensitivity and resolution. Exploiting the proximity of z~0.2 LBG analogs (LBAs) and close engagement with theory, we propose to obtain 0.2" resolution CO(3-2) line observations to address three key questions that are difficult or impossible to tackle directly at high redshift. First, we will analyze LBAs' molecular gas kinematics to assess whether gravitational instability or star formation feedback drives the turbulence that dictates the collapse of clouds to form new stars. Second, we will determine whether and how LBAs diverge from the global and resolved Kennicutt-Schmidt relation seen in ordinary star-forming galaxies at z=0. Third, we will investigate whether and how shocks and star formation feedback impact the molecular gas reservoirs of LBAs. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2024-03-08T17:08:49.000 |
| 3111 | 2022.1.00174.S | 19 | Time Filler: Feedback Scaling Relations for Gas Infall and Outflows in Massive Starburst Galaxies at Redshifts 1.5-6 | ALMA has recently demonstrated that the ground-state OH+ transitions are an ideal tracer of stellar feedback in massive starburst galaxies back to the first billion years of cosmic time based on detections in ~20 systems at redshifts 2-6. Most detections were obtained with the ACA, revealing a mix of red- and blueshifted absorption, emission, P-Cygni, and inverse P-Cygni line profiles, which are characteristic of gas infall and outflows - revealing the gas supply for the starbursts, and the feedback terminating them. These modest samples revealed relationships between the dust temperature and OH+ optical depth, and the OH+ emission strength and far-IR luminosity/star formation rate, but with substantial scatter. Here, we aim to significantly improve the statistical significance of these relations, and to identify the best cases suitable for high-resolution follow-up with the 12m array by targeting 70 of the brightest lensed starbursts across the sky from the SPT, ACT and Planck surveys, with a particular focus on less subscribed LST ranges. Given the simple selection on apparent brightness, sample completion is not essential, making this an ideal time filler project. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-03-23T20:33:44.000 |
| 3112 | 2016.1.01567.S | 103 | Spectral scan of CO emission from z>6.5 PanSTARRS1-WISE QSO candidates | We propose ALMA spectroscopy of 17 QSO candidates at z>6.5 jointly selected from the WISE and new PanSTARRS1 3pi surveys. The combination of the WISE and PS1 bands allows for cleaner separation of z>6.5 QSO candidates from the brown dwarfs, compared to the previous studies. To measure the redshifts of the candidates we propose a new and time efficient spectroscopic survey with ALMA, by simultaneous spectral scans of CO(6-5) and CO(7-6) emission in Band 3. The spectral scan in the lower receiver sideband within 84 and 92 GHz aims at detection redshifted 6.56.5 QSOs are known. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-04-07T09:21:18.000 |
| 3113 | 2023.1.01722.T | 0 | Using type-I X-ray bursts to reveal neutron star jet speeds | Jets are powerful, collimated outflows that are a ubiquitous feature across accreting compact objects and cataclysmic transients. Despite their importance, precisely how jets are launched and their speeds remain unknown, in particular for objects with a stellar surface. For accreting neutron stars, it is debated whether the jets are powered by magnetic fields anchored in the accretion flow or in the star itself. Our recent discovery of bright jet flares connected with type-I X-ray bursts can answer this key astrophysical question. Our result provides a measurement of the compact jet speed from a neutron star, and how the magnetic field behaves during changes in the disk structure. However, the experiment was limited due to the poor instantaneous uv-coverage and sensitivity of ATCA. As such, we were unable to explore individual radio flare events on short timescales, and determine how they differ between bursts. Here, we propose a pilot VLA (sub-array at C, X, and Ku-band) and 7-m Atacama Compact Array (ACA) 100 GHz observations of a bursting neutron star to identify how individual bursts impact the jets, revealing how neutron star jets are powered. | Outflows, jets and ionized winds | ISM and star formation | 2025-11-12T17:12:53.000 |
| 3114 | 2022.1.00120.S | 0 | Resolving the Star-Forming Gas of a Main-Sequence Galaxy at Cosmic Noon | In terms of resolution, observations of molecular gas still lag significantly behind those of the stellar emission at z~2. Thus, crucial questions remain open, e.g.: What were the main sites of star formation at Cosmic Noon? What was the temperature, density and kinetic energy content of the star-forming gas? We propose to start answering these by resolving the CO(2-1) and CO(5-4) emission of a typical z=1.6 main-sequence galaxy, down to a physical resolution of 1kpc. With the proposed CO(2-1) observations, we will identify whether the molecular gas is distributed in a large central reservoir, kpc-size clumps or structures more typical of local galaxies. We will measure the gas velocity dispersion down to 20 km/s allowing us to distinguish between thin and thick disks for the first time at z>1. Additionally, by resolving the CO(5-4) emission we will model radial variations in the temperature and density of the molecular gas, thereby identifying the sites of ongoing star formation. Selected from the HUDF, our target is one of the best-studied main-sequence galaxies at Cosmic Noon and presents the ideal opportunity to connect deep high-resolution multi-wavelength observations. | Galaxy structure & evolution | Galaxy evolution | 2024-11-21T11:39:34.000 |
| 3115 | 2013.1.01091.S | 18 | Sub-parsec scale structure of quiescent molecular clouds possibly pre-forming clusters | The Large Magellanic Cloud is the nearest neighbor to the Galaxy, and its nearly face-on view allows us to unambiguously identify young objects associated with GMCs over a galaxy. We classified the GMCs into three types according to the activities of massive star formation, corresponding to the evolutional sequence of the GMCs. One of the features of the GMCs in the LMC is that there are many starless GMCs, suggesting that the timescale in star formation is significantly longer than in the Galaxy. This may be due to the higher ionization degree and smaller cooling rate as a consequence of lower metallicity in the LMC, and it is tempting to speculate that there is a link between populous clusters and the starless GMCs. Our Cycle 1 approved program will map 5 GMCs of different GMC types to resolve molecular cloud cores at sub-parsec scales in CO. Here we propose to follow-up on the two youngest GMCs, G225 and N166, to probe the high-density clump mass structure and to characterize precluster forming cores, which leads to the understanding of the possible origin of high activities of star and cluster formation in the LMC. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2016-06-16T08:48:07.000 |
| 3116 | 2019.1.00363.S | 190 | WISDOM: Constraining the scatter in the M-sigma relation at fixed velocity dispersion | SMBH masses correlate most tightly with the stellar velocity dispersion of their hosts, but whether the same relation holds for early- and late-type galaxies remains an open question. Various works suggest that massive LTGs follow an M-sigma relation with a similar slope, but lower normalisation than ETGs. This lower SMBH mass at fixed sigma is typically regarded as evidence for the role of SMBH accretion in quenching. However, making strong conclusions is hindered by systematic differences in the techniques used to measure SMBH masses in these different objects. Molecular gas SMBH measurements are the ideal tool to remove this uncertainty. We here propose to begin to answer this question in a targeted manner, using ACA observations for a sample of galaxies in a narrow velocity dispersion range to map the molecular gas in these systems and ascertain whether these are suitable for high-resolution follow up. Given the small uncertainties, with a sample of molecular SMBH masses measurements for 10 ETG and 10 LTG in this range we can robustly measure the offsets relative to the M-sigma relation, and determine whether early and late type galaxies truly follow the same scaling relations. | Galactic centres/nuclei | Active galaxies | 2021-02-18T16:50:46.000 |
| 3117 | 2019.1.01130.S | 6 | Detecting a possible misalignment in the circumtriple disk around GW Ori | GW Ori is a young hierarchical triple system. It has a large circumtriple protoplanetary disk, one of the only few of its kind. Our ALMA Cycle 5 observations of the system have discovered three dust emission rings in the disk. Most excitingly, we found two tentative pieces of evidence for a misalignment between the inner and outer parts of the disk: one in the shape of the rings in the dust emission, and the other in the velocity map in the 12CO line emission. The misalignment, if confirmed, strongly suggests ongoing dynamical interactions between the stars and the disk. However, the low angular resolution in our previous observations prevents us from confirming (or ruling out) the misalignment. We propose to observe this disk in dust continuum emission in Band 4 with an angular resolution of 40 mas to fully resolve the rings, and to precisely measure the shape of the inner two rings. Our proposed observations will allow us to confirm the tentatively identified misalignment, and offer valuable information for studying dynamics in a rare circumtriple system. | Disks around low-mass stars | Disks and planet formation | 2022-09-23T13:08:34.000 |
| 3118 | 2013.1.00286.S | 1 | Particle acceleration and magnetic field in the hot spot of 3C 445 | We propose ALMA observation in polarization mode of the peculiar hot spot 3C 445 South. The discovery in this hot spot of optical synchrotron emission extending on kpc scale challenges the standard scenario of particles accelerated by a strong shock. High-energy electrons like those responsible for the optical emission should arise from a very small region due to their short radiative time. Two scenarios have been proposed to explain such extended optical emission: multiple, broadly distributed shock structures, or efficient Fermi-II acceleration mechanisms driven by turbulence. The key parameter to discriminate the mechanism at work is the polarization intensity: high fractional polarization is expected in the former case, while low values or absence of polarization in the latter. The aim of this proposal is to discriminate between the two scenarios by studying the polarization properties in the peculiar hot spot 3C 445 South and to determine the topology of the magnetic field across the whole structure to probe the presence of compressed/shocked regions. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-12-20T11:53:28.000 |
| 3119 | 2013.1.00251.S | 6 | Mass loss on the RGB: reaching the limits | For stars with initial masses below about 1 Msol, mass loss on the first red giant branch (RGB) dominates that on the later AGB phase. Nevertheless, RGB mass loss is always parameterised by a simple Reimers law in evolution models. Groenewegen recently showed that mass loss exists in nearby RGB stars from modelling the SEDs. As follow-up, 5 stars were observed with IRAM and APEX. HIP 53449 was detected in the CO 2-1 line (and marginally in 3-2), the object with the largest mass-loss rate based on the previous analysis of the SEDs. The shape of the line profiles is intruiging. The expansion velocity is unexpectedly large, and there is a hint for a rotating disk. The comparison to a line emission code suggests that the CO envelope is significantly smaller than follows from the photodissociation radius. It is proposed to observe HIP 53449, and the star with the next largest detection probability HIP 67665, in the CO 2-1 and 3-2 lines. The observations will unequivocally determine the line profiles. More importantly the spatial resolution of ALMA will allow to determine the size of the CO enveloppe and show if it is indeed much smaller than the standard photodissociation radius. | Main sequence stars, Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2016-02-26T14:47:44.000 |
| 3120 | 2018.1.01526.S | 60 | First detection of the hot intra-cluster gas in a proto-cluster at z ~ 2 | We propose to use the imaging capabilities and spatial resolution of ALMA in Band 3 to detect the Sunyaev-Zel'dovich Effect (SZE) from the proto-cluster region surrounding one of the most studied proto-clusters known in the literature: the Spiderweb galaxy (MRC 1138-262) at redshift 2.16. This will be the first detection of the intra-cluster medium in a high-redshift progenitor of a present-day massive cluster of galaxies. We use state-of-the-art numerical simulations to show that a combination of compact ALMA configuration, long baseline ALMA configuration, and ACA will optimally remove the contamination from the central radio-galaxy and allow to measure the SZE signature from the core to the cluster radius. The proposed observations will shed light on the link between the formation of dark matter halos, traced by the presence of the intra-cluster gas, and the formation of cD galaxies in a very early epoch of cluster formation, a hitherto unexplored redshift regime inthe research field of galaxy clusters. As added value, with the same data-set we will be able to trace the correspondence between the H$\alpha$ and molecular gas traced by CO. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2020-02-07T20:10:42.000 |
| 3121 | 2015.1.00296.S | 32 | A First Deep Survey of Sulfur Chemistry in Protoplanetary Disks | One of the major mysteries related to the initial stages of planet formation is the chemical composition of protoplanetary disks. While a dozen of C-, O- and N-bearing molecules have been detected, the sulfur content of disks remains largely unexplored, with only CS and SO being detected. This is in strong contrast with the studies of low- and high-mass star-forming regions where several sulfur-bearing species are routinely observed. We show that SO, SO2, H2S, OCS, CS, and CCS can be employed as uniques probes of the dynamics, grain growth, surface chemistry, and X-ray ionization in protoplanetary disks. Our goal is to perform the first deep study of sulfur chemistry in the two well-known protoplanetary disks. We aim to observe a low-mass TTau star (DM Tau) and an intermediate-mass Herbig Ae star (MWC 480) in SO, SO2, OCS, H2S, CS and CCS in the Band 6 at the 0.5" spatial and 0.3 km/s spectral resolution. The amount of observing time required to detect most of these lines is estimated to be 1.8 hour per source, or 3.6 hours in total. | Disks around low-mass stars | Disks and planet formation | 2017-12-02T14:06:43.000 |
| 3122 | 2021.2.00175.S | 77 | An ACA census of Galactic metal-poor molecular clouds | Metallicity is one of the key properties of molecular clouds (MC) that regulate star formation (SF). Low-metallicity (low-Z) can suppress the cooling and fragmentation of MCs, leading to large clumps and low-SF efficiency. MCs on the Galactic outer disks are metal-poor (~1/2-1/5 Zsolar), as excellent analogues to extragalactic metal-poor systems. Our recent IRAM 30-m observations of Galactic low-Z MCs show consistency with the Larson's size-linewidth relation. They show systematically lower turbulence level than MCs in the Galactic inner disk. On the other hand, the dust emissivity index show very small values (1.1~1.5), comparable to the outskirts of M31 and Magellanic Clouds. In this proposal, we propose a census of molecular gas and dust in a sample of metal-poor MCs in the Galactic outer disk. These data will allow the first systematic study of distribution/kinematics/turbulence of molecular gas and dust emission in low-Z MCs and their impact to SF. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-06-02T20:30:45.000 |
| 3123 | 2015.1.00356.S | 16 | Dense Molecular Gas in Post-Starburst Galaxies: A New Laboratory for What Stops Star Formation | We have identified a unique sample of post-starburst, post-merger galaxies whose tidal features, bulge- dominated morphologies, evolving color gradients, and young globular cluster populations show them to be in transition between late- and early-types (Yang et al. 2004, 2006, 2008). Remarkably, we have discovered molecular gas traced by CO (1-0) in over half the sample, forcing these galaxies off the classical Kennicutt-Schmidt relation. In other words, they have significantly higher molecular gas surface densities than predicted by their star-formation rate (SFR) densities. This result suggests a lower star formation efficiency than for normal star-forming galaxies with the same gas densities, making post-starburst galaxies a new laboratory for linking the physics of star formation on small scales to galaxy-wide trends. Here, we propose to target two of the most COluminous, yet star formation deficient, galaxies. Only ALMA can measure the actual fuel for star formation the denser gas traced by HCN, HCO+ and HNC to determine what is preventing stars from forming. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2018-03-08T14:42:48.000 |
| 3124 | 2018.1.01135.S | 8 | Resolve SiO and methanol Mega-Masers in NGC 1068 by ALMA | We propose to spatially resolve the millimeter SiO and CH3OH mega-masers in the nearby type II AGN NGC1068 with ALMA. The high resolution data from ALMA will constrain the origin of these mega-masers from the accurate locations of their emissions for the first time. With the kinematic and spatial constraints, we will also measure the mass of the central supermassive black hole and study its feedback to the surrounding ISM. These newly discovered mega-masers potentially will open a new window for studying type II AGN in the coming years with ALMA and next generation VLA (NgVLA) with great sensitivity. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-07-14T11:43:36.000 |
| 3125 | 2012.1.00336.S | 0 | A Complete, High Resolution View of Low Metallicity Star-Forming Complexes in NGC 6822 | We propose to map CO 2-1 and 1.3mm dust continuum emission across a varied set of five star-forming regions in the well-studied Local Group (d=490kpc), low metallicity (12+logO/H=8.11) dwarf galaxy NGC 6822. These observations will measure the structure of star-forming molecular clouds at low metallicity with unprecedented spatial (1.6"=3.8pc) and spectral (0.5MHz=0.6km/s)} resolution, exceeding the resolving power of previous interferometric studies of dwarf galaxies by an order of magnitude. We will use the data to make a complete census of dust and molecular gas across each 27-point (200pc) field and measure the structure of this material -- the interplay of dust and CO luminosity, radius, line width, and morphology -- on scales from 4 to 200pc. This will give us the best view to date of how low metallicity affects the structure of star-forming gas -- the balance of HI and H2, the distribution of CO, and the small-scale morphology of clouds. In the process, we will place several independent constraints on the CO-to-H2 conversion factor, which is still poorly understood at low metallicities, and examine the interplay of cloud structure and recent star formation across our fields, which have been picked to host varied star formation environments. NGC 6822 represents the only viable target for such observations -- one cannot achieve the needed combination of resolution and sensitivity outside the Local Group and other Local Group dwarfs are either too quiescent or -- in the case of the Magellanic Clouds -- are so nearby that spatial filtering and the mosaic field limit prohibit a complete view of star-forming complexes | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2015-04-15T11:23:12.000 |
| 3126 | 2016.1.00459.S | 66 | Disks with faint CO: low gas/dust or large carbon depletion? | A recent ALMA census of all protoplanetary disks in Lupus has revealed a large fraction of sources with faint CO isotopologues lines. This may be translated either into low gas masses and gas-to-dust ratios or into chemical evolution, sequestering carbon into other forms. Either these disks are in an evolved stage where most of their gas has been dissipated, or CO is not the main carbonaceous species, but instead carbon is locked up in more complex refractory carbon-bearing molecules. The aim of this proposal is to observe carbon bearing molecules such as C2H, and C3H2, whose abundances are particularly sensitive to carbon abundance and C/O ratio and whose emission will help to disentangle low gas/dust ratios from large carbon depletion. We propose to observe a carefully selected subsample of disks with a range of inferred gas/dust ratios in band 6, at a spatial resolution of 0.25" for a total integration time of 6 h. | Disks around low-mass stars | Disks and planet formation | 2018-12-31T00:00:00.000 |
| 3127 | 2016.1.00946.S | 43 | Utilizing Dense Gas to Solve the Variations of Molecular Gas Depletion Time | Recent observations show that the molecular gas depletion time varies in the centers of galaxies. Since stars form in the densest part of star-forming clouds, one possible explanation is that galaxy centers have different fractions of dense gas than in the disk. Here, we propose to observe HCN and HCO+ (as tracers of dense gas) in three selected galaxies that are resolved in the CO (from the EDGE survey) and H-alpha lines (from the CALIFA survey). This observation will illuminate whether different fractions of dense gas (i.e., HCN/CO ratio) are the main drivers of the variations of depletion time between the center and the disk of galaxies. Furthermore, we also investigate whether the depletion time of dense gas (i.e., HCN/SFR ratio) in the galaxy centers also varies. With ALMA, we can detect HCN down to a sensitivity where CO is detected in the galactic disks of the EDGE survey. This allows direct comparisons of HCN/CO ratio and HCN/SFR ratio over the galaxy disk and centers at a matched angular resolution as in the EDGE and CALIFA surveys. | Starbursts, star formation, Galactic centres/nuclei | Active galaxies | 2018-02-21T16:57:13.000 |
| 3128 | 2015.1.00320.S | 64 | Star formation suppression in recent minor mergers | In a hierarchical LambdaCDM universe mergers play a major role in the assembly of galaxies, inducing strong star formation, fuelling black-hole growth and morphologically transforming galaxies. Wet mergers are usually associated with strong starbursts, as gas dissipatively collapses to the galaxy centre. A recent paper by Davis et al. (2015) found a population of very gas rich galaxies, which have recently undergone a minor merger. Contrary to expectations these coalesced systems do not host strong starbursts. Instead star formation is suppressed by orders of magnitude, with gas depletion times that exceed the Hubble time. We propose to use ALMA to determine the underlying physical cause of this intriguing effect, distinguishing between dynamical suppression, gravitational heating and AGN/starburst feedback both kinematically and chemically. A small investment of ALMA time will allow us to place these objects on a 'suppression sequence', comparing them to more normal early-type and star-forming objects, and to purpose-built hydrodynamic simulations. In this way we can shed light on a physical process that can suppress and regulate star formation across the Universe. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2017-07-26T20:31:19.000 |
| 3129 | 2017.1.00562.S | 66 | Multi-band observations of starburst cores in massive galaxies at z=2.5 | We propose 0.15arcsec (1 kpc)-resolution multi-band observations in two massive star-forming galaxies at z=2.5 to observe the dust continuum emission over the wavelength range of 440 um-1.3 mm, the CO(3-2) and the CO(7-6) lines. They are both associated with extremely compact starbursts with the effective radii of Re=1 kpc, suggesting rapid formation of the bulge components. The physical conditions of the interstellar medium in the starburst cores are important for understanding how the bulge stars are formed in the most massive galaxies at the peak epoch of star formation activity. Exploiting the multi-band data, we will investigate the radial gradients of [1] extinction-free star formation rate from the 440 um flux densities, [2] dust temperature from the far-infrared Spectral Energy Distribution (SED), [3] star formation efficiency from the far-infrared luminosities and CO luminosities, and [4] gas excitation from the luminosity ratio of CO(7-6) to CO(3-2) line. Therefore, the proposed observations will provide crucial information for understanding the physical conditions of the interstellar medium where the compact cores are being formed. | Starburst galaxies | Active galaxies | 2019-10-08T23:05:19.000 |
| 3130 | 2018.1.01684.S | 101 | Multi-line measurements of cloud mass functions in the starburst ring of NGC 1068 | We propose to conduct 0".4 or 28-pc resolution 12CO and 13CO(1-0) imaging of NGC 1068. CH3OH, CN, and CS will also be observed for free. Immediate objectives are (1) to construct GMC catalogs using both optically-thick-but-bright 12CO and less-luminous-but-optically-thin 13CO data, with a careful comparison of physical properties of 12CO-based and 13CO-based GMC catalog, (2) to obtain cloud mass functions (CMFs) for the identified GMCs as a function of environment, and (3) to study methanol abundance of GMCs and their dependence of environment. In our previous 100-pc resolution 13CO(1-0) observations of NGC 1068, we found that the high-mass end of the measured CMF in the cirumnuclear starburst regions has significantly higher cut-off mass compared with that in normal star-forming galaxies. With the proposed 28-pc resolution data, we will confirm if the starburst region is surely characterized by such a high-mass dominated CMF than normal galaxies. We will also test a possible connection of CH3OH abundance enhancement and the presence of shock presumably due to cloud-cloud collisions in spiral arms, which was found in our previous ALMA data. | Starbursts, star formation | Active galaxies | 2021-01-16T09:03:38.000 |
| 3131 | 2018.1.01873.S | 3 | Testing protostellar dust polarization properties in different local conditions | Polarized dust emission is routinely used as a good tracer of magnetic field lines in star-forming cores. We have developed a chain of ALMA synthetic observations of polarization from non-ideal MHD simulations of protostellar collapse, including both the dust properties and dust alignment physics such as radiative torque alignment (RAT) to interpret our ALMA dust polarization observations in the B335 protostar, and found it is very difficult to reproduce finely the dust polarization in B335 using a single dust alignment mechanism. Since these observations are routinely used to assess the role of magnetic field to shape the disk, binaries and overall star formation processes, it is crucial to now test the grain alignment mechanisms producing the polarization signal in the complex environment taht are protostellar envelopes. We propose to carry out multi frequency ALMA observations of the polarized dust emission in B335 to complement our Band 6 observations, where the local conditions are well characterized thanks to a wealth of ancillary datset. | Low-mass star formation | ISM and star formation | 2021-01-22T12:24:55.000 |
| 3132 | 2019.1.00195.L | 14269 | ALMAGAL: ALMA Evolutionary study of High Mass Protocluster Formation in the Galaxy | A large fraction of stars form in clusters containing high-mass stars, which affect the local and galaxy-wide environment. Yet fundamental questions about the physics responsible for fragmenting molecular Clumps into Cores are still open. What are the physical characteristics of core fragments in dense clumps as a function of evolution? To what extent is fragmentation driven by dynamics in clumps or mass transport in filaments? ALMAGAL aims at observing 1mm continuum and lines toward more than 1000 dense clumps with M>500 M_sun and d < 7.5 kpc with similar linear resolution. The sample covers all evolutionary stages from IRDC to HII regions from the tip of the Bar to the outskirts of the Galaxy. The setup with 0.1 mJy sensitivity will enable a complete study of the clump-to-core fragmentation process down to at least 1000 AU and 0.3 M_sun Galaxy-wide, mapping the temperature and the local/global infall velocity patterns of the cores-hosting clumps. ALMAGAL publicly accessible data cubes and catalogs will be an invaluable legacy of ALMA, that will allow numerous community followup studies. To increase the impact, we will waive our proprietary rights on the entire dataset. | High-mass star formation | ISM and star formation | 2019-10-23T12:48:18.000 |
| 3133 | 2019.1.01663.S | 120 | Testing the Connection Between Fast Radio Bursts and Superluminous Supernovae with ALMA | The first precise localization of a fast radio burst (FRB121102) led to two unexpected results: (i) a low metallicity dwarf host galaxy, and (ii) a spatially coincident quiescent radio counterpart. The host galaxy is identical to the hosts of hydrogen-poor superluminous supernovae (SLSNe), a rare type of core-collapse SNe powered by magnetars, while the quiescent radio source may be a nebula associated with the FRB. In a recent paper we argued that these results indicate that FRB121102 is powered by a millisecond magnetar born in a SLSN explosion ~30 years ago. A strong prediction of this model is that known SLSNe that are a few years old should also exhibit nebulae, but with a peak in the mm-band. Here we propose to carry out such a search, targeting a complete sample of all SLSNe (12 sources) that are < 4 years old, located at z<0.4, and are visible to ALMA; these cuts lead to an expected flux density of >0.1 mJy at 100 GHz. Detections of associated nebulae will have profound implications for our understanding of both FRBs and SLSNe, while non-detections will invalidate our proposed model. We will couple the ALMA results to our modeling of the optical/UV data of the SLSNe. | Supernovae (SN) ejecta | Stars and stellar evolution | 2021-02-07T16:01:43.000 |
| 3134 | 2021.1.01130.S | 98 | Dense Gas in Strongly Lensed Dusty Star-Forming Galaxies | The relationship between star formation and the dense self-gravitating gas is critical for our understanding of galaxies. Yet, there are few measurements of this gas phase in high-z galaxies. We propose ALMA Band 3 & 4 observations of the J=4-3 and 5-4 lines of HCN, HNC, and HCO+ towards 10 strongly lensed dusty star-forming galaxies (DSFGs) selected from the South Pole Telescope sample over the redshift range z=2-4. These lines trace dense gas associated with star-forming cores capable of surviving the extreme ISM conditions at high redshifts. The 10 sources targeted have well-constrained total gas masses, star-formation rates, and lens models. The proposal will be the first survey of dense gas in the high-z DSFG population. It will tell us if high-z DSFGs have higher dense gas fractions than local starbursts, and whether model predictions, based on local surveys, apply at high redshifts: does the dense gas star-formation efficiency depend on the dense gas fraction or is it universal? The observations will be sensitive to emission from the mid-IR-pumped vibrational HCN lines, which will gives a first constraint on the fraction of our sources that are compact obscured nuclei. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-03-07T15:13:44.000 |
| 3135 | 2023.1.00462.S | 0 | Heating and Cooling of the cold ISM on the z=2 Main-Sequence with ALMA+JWST | Galaxies ten billion years ago formed their stars more efficiently. Why? Ultimately, the transformation of molecular gas into stars is a function of how gas heats and cools, the details of which can be measured by combining far-IR spectroscopy from ALMA with mid-IR JWST/MIRI observations. To study how stars form in typical galaxies at the peak epoch of star formation, we select a sample of five z~2 main-sequence galaxies on the basis of bright Polycyclic Aromatic Hydrocarbon (PAH) emission measured by JWST/MIRI which is essential for measuring gas heating. In this survey, we will obtain [C II] which traces gas cooling to measure the photoelectric heating efficiency with the [C II]/PAH ratio: never before measured in typical galaxies at z>0. These observations will provide the first solid link between [C II] and PAH luminosities at z~2 in normal star-forming galaxies, providing insight into the physics of photoelectric heating of the ISM and how this shapes the efficiency of star-formation when most of the stars in today's Universe were formed. | Starbursts, star formation | Active galaxies | 2025-10-15T02:10:40.000 |
| 3136 | 2023.1.01488.S | 0 | Confirming a circumplanetary disk around J1407b | In 2007 a complex eclipse lastting two months was seen towards the young (17 Myr) star J1407 in the Scorpius-Centauraus OB association. The most probable explanation was that a circumplanetary disk about 1au in diameter occulted the star. ALMA observed this field in July 2017 (ALMA project 2016.1.000470.S) and detected a point source with the expected brightness - but not at the projected position of the star that the planet's orbit would suggest. We request a follow-up observation to establish the current position of the source and distinguish between the two most likely scenarios: a free floating planet with a circumplanetary disk (if the source has moved away along a vector aligned with the 2007 position of the star), or a background galaxy (if the source shows no proper motion). The temporal baseline is large enough to clearly distinguish between these cases. | Debris disks, Exo-planets | Disks and planet formation | 2025-07-22T12:12:19.000 |
| 3137 | 2021.1.00862.S | 117 | The Evolution of Molecular Outgassing in Distant Comet C/2017 K2: A Joint ALMA/JWST Monitoring Campaign Across Ice Lines | We propose ALMA Cycle 8 observations of the distantly active Oort cloud comet C/2017 K2. These observations will provide crucial information regarding molecular abundances and outgassing in support of approved JWST Cycle 1 and planned JWST Cycle 2 observations targeting K2. The overall scientific goal is to observe K2 at multiple heliocentric distances (rH) both pre- and post-perihelion, following K2 to the distant reaches of the solar system. These measurements will trace the evolution of molecular activity as K2 crosses the ice lines - the rH at which sublimation of each volatile species activates (6-8 au for CO, 2-3 au for H2O). Our objectives are to quantify the abundances and spatial distributions of CO, H2CO, CH3OH, CS, HCN, and HNC over a range of rH, including before and after the coma is dominated by H2O production. These data will enable a transformative and detailed investigation of the evolution of cometary activity as a function of primary driver (H2O or CO), providing a comprehensive record of the progression of activity from the outer to the inner solar system and yielding fundamental insights into coma dynamics and activity across a perihelion passage. | Solar system - Comets | Solar system | 2023-10-04T10:16:54.000 |
| 3138 | 2015.1.00862.S | 13 | Molecular gas and star formation in normal galaxies at z=1.47-2.23 | We propose to observe the global molecular gas content in a sample of four normal (main sequence) star-forming galaxies taken from the COSMOS and UDS fields at z=1.47 and 2.23, respectively. The targets are taken from the HiZELS survey and have exquisite multi-wavelength coverage, including VLT/SINFONI or Gemini-N/NIFS IFU AO-aided maging at ~0.15" of the Halpha emission line, probing the kinematical details of the ionised gas: mergers or thick-disk clumpy galaxies. The targets are representative to the bulk of the high-z galaxies, and measuring their molecular gas content (M_H2) provides a unique way for estimating their evolutionary state in the Universe. In particular, we use band-3 to detect at ~2" the CO(2-1) and CO(3-2) emission line for galaxies at z=1.47 and 2.23, respectively, allowing a global estimate of M_H2, depletion times via M_H2/SFR and gas fractions, in comparison to similar quiescent star-forming galaxies seen locally. The proposed four galaxies will double the number of HiZELS galaxies with CO detections at z>1. | Galaxy structure & evolution | Galaxy evolution | 2017-06-25T08:53:15.000 |
| 3139 | 2017.1.01308.S | 102 | A multi-epoch and multi-wavelength observation of a variable YSO (EC 53) in Serpens main | We propose a multi-epoch and multi-wavelength ALMA observations of a variable protostar EC 53, whose outburst event was recently detected by our JCMT large program, "A transient search for variable protostars", with ACA at bands 6 and 7. EC 53 has been known as a variable YSO in K-band, and the variability is likely caused by the binary interaction. Since the sub-mm light curve, detected by the JCMT/SCUBA2, shows a strong resemblance to the K-band light curve with a period of ~540 days, the (sub)mm flux variation of the source is predictable. Therefore, EC 53 will provide a unique test-bed to capture the moment of accretion burst and to study the effect of outburst on the SED. Our planned observation will monitor the variability of the SED around its brightness maximum in (sub)mm, which will allow us to estimate the change of accretion rate in the source, modulated by a close binary. | Low-mass star formation | ISM and star formation | 2019-07-19T11:09:56.000 |
| 3140 | 2021.1.00041.S | 137 | Uncovering galaxy assembly along cosmic web filaments with [CII] | The current framework in a cold dark matter universe predicts that galaxies form and evolve along cosmic web filaments. While tracing diffuse cool gas in the filaments had been elusive for years, Lya filaments on Mpc scales has been recently identified in a z=3 proto-cluster. This field therefore provides a unique laboratory to uncover how galaxy assembly takes place in the cosmic web filaments. Here we propose to map and resolve [CII] emission, the brightest line in submm, in 16 dusy starburst galaxies (submillimeter galaxies, SMGs) which have spec-z=3.09 and embedded in the filaments. Our aim is (i) to characterize gas kinematics and uncover mechanism behind the enhanced star formation, (ii) to test spin alignment with the filaments, (iii) to diagnose the ISM states and unveil how the filaments effect the ISM nature, and (iv) to perform unbiased [CII] deep survey along the filaments. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2023-05-12T06:44:20.000 |
| 3141 | 2017.1.00161.L | 1530 | ALCHEMI: the ALMA Comprehensive High-resolution Extragalactic Molecular Inventory | A great variety in gas composition is observed within galaxies, which suggests that chemistry may be a powerful diagnostic of galaxy evolution. The increase in sensitivity and frequency coverage of mm/submm facilities has recently made it possible to study the chemical complexity of the molecular interstellar medium beyond the Milky Way. However, most extragalactic spatially resolved studies are limited to a few, bright low-J transitions, which do not allow for a unique solution to the molecular excitation and result in degenerate chemical models. This situation can be changed only through an ALMA large program. We propose to perform a multi-band (bands 3,4,6,7), beam-matched spectral scan of the central molecular zone (850x340pc) of the starburst galaxy NGC253 at giant molecular cloud (GMC) resolution (1"=17pc). The observations will result in the most complete extragalactic molecular inventory and will provide the extragalactic community with reliable templates of chemistry and excitation in a starburst at GMC scales. These data will be used to benchmark molecular diagnostics and chemical models, and will serve as a guide for future observations in the near and distant Universe. | Galaxy chemistry, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2020-02-18T17:16:04.000 |
| 3142 | 2015.1.00978.S | 32 | Revealing the Cause of "Starburst"-like Conversion Factors in Nearby Galaxy Centers | We propose to take a key step in understanding what physical processes control the CO-to-H2 conversion factor by using ALMA to characterize molecular gas properties in nearby galaxy centers where we observe low, starburst-like Xco. We will observe 12CO (1-0); 13CO and C18O (2-1) and (3-2); and dust continuum at matched GMC-scale (60pc) resolution. The spectacular sensitivity and resolution of ALMA make these faint diagnostics easily obtainable in nearby galaxies for the first time. In particular, the ability to measure multiple rotational levels of optically thin C18O emission lets us self-consistently measure cloud masses and excitation temperatures. Using these observations we will test several hypotheses for why Xco is low in these regions: (1) enhanced temperature and/or decreased density in virialized giant molecular clouds (GMCs), (2) CO emission from molecular gas not associated with GMCs or (3) GMCs that are unbound or under external pressure. The study we propose is the necessary, timely and feasible next step towards understanding Xco and will provide crucial information for future studies attempting to measure molecular gas masses in galaxies across the Universe. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2017-04-12T22:54:04.000 |
| 3143 | 2017.1.01621.S | 34 | ALMA reveals the full extent of the earliest known merger shock | ALMA has provided the first Sunyaev-Zel'dovich (SZ) effect measurement of a merger shock at high redshift, located in the famous `El Gordo' galaxy cluster (z=0.87). The cluster's prominent NW radio relic was imaged in Band 3 continuum to detect a pressure discontinuity in the underlying intracluster plasma. Deep Chandra X-ray observation, on the other hand, reveals a tentative shock front that extends far beyond the limits of the relic synchrotron emission and the current ALMA pointing. It is difficult to obtain a more precise characterization of this high-z shock from X-rays without investing a significant amount of exposure time (>200 h). Our ALMA proposal aims to image the entire shock front in the SZ effect instead, to answer whether there is really a 1.5 Mpc shock front in this famous galaxy cluster, if the Mach number is constant across the shock, and why only a small part of it glows in the radio synchrotron. The results will have a broad impact on the general study of cluster mergers and shocks, extending it to the very early epoch when the galaxy clusters were first assembling. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE) | Cosmology | 2019-05-10T08:23:56.000 |
| 3144 | 2016.1.00932.S | 72 | COLDz: Gas Excitation in "Typical" CO(J=1-0)-Selected Galaxies at z=2-3 | In two decades of studies of molecular gas in high-redshift galaxies, we have gained deep insight regarding the gas properties of individually selected, massive galaxies and their parent samples out to z>6. However, a coherent census of the gas content of galaxies through cosmic times ("cold gas history of the universe") is still elusive. We have recently carried out this groundbreaking measurement over a large cosmic volume at redshifts 2-3 and 5-6 through a large, deep 500hr survey with the VLA. By targeting the ground-state CO 1-0 line, this novel study is free of excitation bias. We here propose to investigate the CO excitation properties of this unique, CO 1-0 selected sample by detecting CO 3-2 or 4-3 emission and dust in 5 representative sources in our sample, covering a significant range in gas and stellar masses and star formation rates - allowing us to place them into context with other known high-z galaxy populations. The outcome of this comprehensive investigation will critically inform any deep field surveys with ALMA, which will ultimately be able to reach even greater depths than the VLA, but which are also limited to selection in the higher-J CO lines targeted here. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2018-02-16T18:58:36.000 |
| 3145 | 2012.1.00382.S | 7 | Outflow Entrainment and Core Dispersal in HH46/47 | We propose to conduct ALMA observations of the HH 46/47 molecular outflow and its parent core to study the entrainment process, the outflow’s impact on its host core, the extent of the infalling envelope, and the outflow-infall interaction. ALMA Cycle 0 observations reveal a beautiful CO outflow that is clearly interacting with the surrounding cloud. However, we currently lack the data to obtain an accurate quantitative assessment of the outflow’s impact on the core and the infalling envelope. In addition, the resolution of the current CO(1-0) data (~4.5") is too low to directly compare it with existing IR maps of the shocked H2 emission, essential for constraining the entrainment mechanism. Here we propose to obtain a mosaic of the CO(1-0) emission with an angular resolution of 1.3", similar to that of maps of H2 shocked emission. We will use a 3D hydro-dynamical code to simultaneously model both the CO and H2 maps, with the goal of providing stringent constrains on the underlying wind structure and the entrainment mechanism. We also propose to observe a set of lines that will probe the dense gas and the outflow's impact on the kinematics and structure of the core. Observations of 13CO, C18O and C17O(1-0) will allow to study the effects of the outflow on the outer and inner regions of the core, over a wide range of densities. Using these lines, we will correct for opacity effects, thereby providing the most accurate estimates of mass, energetics and mass loss rate of any outflow to date. The observations will also help resolve current disagreements on the role of outflows on core dispersal.Observations of the CS(2-1) line will be used to map the infalling envelope and to study the outflow-infall interaction. Our results will help understand the entrainment mechanism in outflows as well the degree at which outflows affect the core-to-star efficiency and the mass-assembling process. | Outflows, jets and ionized winds | ISM and star formation | 2021-05-24T00:00:00.000 |
| 3146 | 2024.1.00869.S | 0 | Imaging metal-sulfides in the Galactic Center cloud G+0.693-0.027 | Metal-sulfides have been proposed as an important reservoir of sulfur in interstellar dust. However, these molecules are difficult to detect in the gas phase of the ISM because metals are highly refractory. Recently, the metal-sulfides NaS and MgS have been discovered toward the Galactic Center cloud G+0.693 by using single-dish observations. The presence of these molecules in this cloud is likely due to the sputtering of dust grains in the shock affecting G+0.693. The derived abundance of NaS and MgS in the beam of the single-dish observations is 4e-13, orders of magnitude lower than the Na and Mg cosmic abundance. However, this emission could be largely diluted in the single-dish beam if generated in compact shocked regions. We propose to image the emission of NaS and MgS in G+0.693, to determine where these molecules arise in the shock and to measure their emitting size and morphology so that their actual abundance can be accurately determined. By comparing the ALMA images with astrochemical modelling, we will constrain the amount of NaS and MgS that reside in interstellar dust grains, shedding light into the sulfur depletion problem. | Astrochemistry | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3147 | 2012.1.00688.S | 0 | Molecular Gas in Young Debris Disks: Constraining the Timescale to Form Ice-giant Planets | Observations of gas in young circumstellar disks are essential to establish the timescale to form planets. While previous data have suggested that gas is depleted on timescales of less than 10 Myr, more recent observations have now detected molecular gas in three debris disks between the ages of 5 and 30 Myr with gas masses upwards of 80 Earth masses. The large inferred gas masses implies that the formation of ice-giant planets may occur over much longer timescales than previously assumed. The growing sample of gas-rich debris disks motivates new observations to empirically measure the lifetime of gas in disks. The time is ripe for such a survey since comprehensive Spitzer observations have discovered numerous debris disks between the ages of 5 and 20 Myr that are excellent candidates to contain molecular gas, and because ALMA provides more than an order of magnitude better sensitivity than previous observations. We propose to search for molecular gas in a carefully selected sample of young (5-20~Myr), luminous debris disks around 1-3 Msun stars to constrain the timescale to form ice-giant planets. | Debris disks | Disks and planet formation | 2015-02-05T17:00:00.000 |
| 3148 | 2022.1.00086.S | 20 | Dissecting the anatomy of the youngest born-again star | After leaving the Asymptotic Giant Branch (AGB), around a quarter of stars are expected to undergo a final helium-shell flash on the white dwarf cooling sequence. This triggers a dramatic born-again event, during which the star temporarily returns to the AGB before re-tracing its evolutionary path in just tens of years. While single-star models are able to adequately reproduce the observed stellar properties during this phase, the morphology of the ejecta expulsed as a consequence of the born-again event appears to be bipolar. This points towards close binarity, which is at odds with current modelling. Only two objects have ever been observed while undergoing a born-again event, the most recent being Sakurai's object. Tantalisingly, existing optical and ALMA observations indicate the possible presence of a torus as well as a bipolar outflow around this star. With the proposed high angular-resolution observations we will create detailed maps of the different components of the molecular ejecta. This will allow us to create quantitative models of the mechanisms at work in this key object and, more generally, probe the late stages of stellar evolution. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-06-16T16:12:48.000 |
| 3149 | 2022.1.00853.V | 0 | Unraveling the nature of the Cen A jet: From cm to mm on light-day scales. | The closest radio-loud galaxy Centaurus A is the ideal laboratory to study extragalactic jet physics on the smallest scales, down to light-days with VLBI observations. At cm wavelengths, the jet has been surveyed extensively, which revealed a complex spine-sheath jet structure. However, only mm VLBI observations are able to probe the jet launching and collimation region close the supermassive black hole in the center of Cen A. With the addition of the LMT to the GMVA, a unique opportunity arises to create the first 3mm VLBI images of this source. We ask for a 6 hour track of GMVA+ALMA observations of Cen A to seize this opportunity. Public data at cm wavelengths and 1 mm EHT+ALMA data from previous observations plus contemporary X-ray data are readily available. Our goal is to combine all these measurements to obtain a broad model of the source and to constrain jet launching and collimation mechanisms by comparing the observations with different large-scale GRMHD and SRMHD simulations. 3mm observations are particularly important to interpret the 1mm data, to measure the spectral index and electron distribution function, and to study the edge-brightening of the jet. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-07-09T09:52:21.000 |
| 3150 | 2021.1.01021.S | 18 | The kpc-scale distribution of dust continuum emission in typical star-forming galaxies at z~1. | We propose to obtain 870um observations with ALMA at 0.2 arcsec resolution of seven (mildly) lensed star-forming galaxies, which lie on and off the main sequence and have a median stellar mass of log(Mstar/Msun) = 10.3, redshift of 1.2, and magnification factor of 2. By characterizing the structure of the interstellar medium of z~1 disks on kpc-scales, wil will look for morphological signatures of the physical mechanisms that drive their high SFR and lead to the assembly of present-day massive disks like the Milky-Way. Moreover, by combining these ALMA observations with existing HST (UV/optical) and VLA (3/6GHz) data, we will derive spatially resolved maps of dust attenuation to infer the dust-corrected SFR and stellar mass radial profiles. We will use this knowledge to contrast the distributions of stellar mass and SFR of galaxies on and off the main sequence, to link the level of star formation with structural changes across z~1 disks. | Starbursts, star formation | Active galaxies | 2023-10-10T22:27:08.000 |
| 3151 | 2016.1.01042.S | 623 | Grain growth and sub-structure in protoplanetary disks | The first step toward forming planets is the growth of sub-micron-sized grains into centimeter-sized particles, within the circumstellar disks that orbit young stars in formation. The long-wavelength emission from large dust grains is the last observable link in the growth chain from interstellar dust to fully fledged planets. Observations of this phase therefore provide crucial constraints on theories of early planetesimal growth and of the transport and evolution of dust particles. In this proposal we request ALMA observations at 1.3mm and 3mm that, when combined with our existing 0.7-1cm spatially resolved observations from the VLA, will determine where in the disk the dust grains are preferentially growing. By characterizing the disk thermal and density structure we have shown that we can determine the dust optical depth and thereby constrain the dust emissivity index throughout the disk. Our proposed ALMA observations will establish whether spatial variations of grain growth occur in nature, as expected from several theoretical scenarios, such as particle trapping at pressure maxima arising from vortices, turbulence, or Rossby-wave instabilities. | Disks around low-mass stars | Disks and planet formation | 2019-09-17T20:42:18.000 |
| 3152 | 2018.1.00034.S | 11 | Probing molecular gas in the Sombrero galaxy's ring | The Sombrero galaxy is one of the best-studied luminous (spiral) early-type galaxies (ETGs), a spheroidal-dominated potential hosting an extended disc and ring of stars, gas and dust. Yet despite being the nearest `spiral' ETG, it has been lacking a deep, high spatial resolution study of its molecular gas content. We propose to remedy that by using the ACA to perform the deepest yet high spatial resolution CO(1-0) line imaging along the galaxy's ring. This will provide crucial information about the faintest gas structures in the central regions (not detected in CO to date), allowing us to study the spatial variation of the H2 mass, gas-to-dust ratio, CO line ratio etc. Together with existing less sensitive CO(2-1) IRAM data at a similar spatial resolution, MUSE Science Verification data, and new deep, detailed imaging of the iconic filamentary dust structures that will come for free with the proposed observations, this ACA CO(1-0) data will itself have both immediate and legacy scientific value. It will also provide the necessary background to allow us to follow up with a detailed study of the molecular gas on Giant Molecular Cloud (GMC) scales using the ALMA 12-m array in Cycle 7. | Early-type galaxies | Galaxy evolution | 2020-12-24T00:00:00.000 |
| 3153 | 2019.1.00507.S | 107 | Monitor 1.1mm line variability in IRC +10216 (IV). | Millimeter line variation is a new direction of evolved star research. The stable array configuration of ALMA ACA makes it the only millimeter interferomter capable of high cadence monitoring. We have pioneered ACA monitoring of 1.1 mm lines to the archetypal carbon star IRC +10216 since 2016 and have covered two maxima of stellar pulsation (period = 1.7 yr) up to now. Very rich mm line and continuum variation patterns have been discovered, including diverse ways to deviate from the NIR light (with NIR data from a companion monitoring). We propose to extend the monitoring into Cycle 7 to cover at least two complete pulsation cycles (3.4 yr) of the star to characterize the periodicity/stability of those strange temporal behaviors. A companion ALMA 12-m array mapping is also proposed for two selected epochs to achieve repeated mapping with similarly high resolutions of 0.24"-0.4" within Cycle 7, with the purpose to understand the narrow line features of some SiS and HCN lines and determine the important emission-region sizes of all lines from the inner circumstellar envelope. The data will provide unique constraints to time dependent theoretical models. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2021-09-03T00:00:00.000 |
| 3154 | 2021.1.01002.S | 6 | Detailed Gas Kinematics and Morphologies of the Highest-redshift Jellyfish Galaxy Candidates at z=1.6 | Jellyfish galaxies with long tentacles of gas and stars, formed due to ram pressure stripping, have offered a new regime in which to study quenching and star formation at low-z. The most distant tail candidate has now been unveiled at z=1.6, enabled by ALMA imaging of molecular gas. This galaxy has an asymmetric gas morphology, an offset stellar-to-gas centroid, and an accelerated velocity gradient along the tail-all signposts of ram-pressure stripping. Moreover, a study of 24 CO-detected cluster galaxies has revealed truncated gas disks compared to stellar disks, indicative of quenching. Here, we propose deeper and higher spectral resolution CO(2-1) imaging of 8 of these gas-rich z=1.6 cluster galaxies, all within the same primary beam, and including the first high-z jellyfish candidate. Through a comparison of molecular gas (ALMA CO), stellar mass (optical HST), and star formation (UV HST), we will place important constraints on cluster quenching efficiencies at z=1.6. Furthermore, we will kinematically and morphologically confirm the highest-z ram-pressure stripped galaxy through gas dynamics and spatially correlated star formation enhancement with molecular gas compression. | Galaxy Clusters | Cosmology | 2022-12-20T18:02:53.000 |
| 3155 | 2019.1.01270.S | 8 | Investigating the origin of an asymmetric dusty ring around CIDA 9 | Rings and gaps are ubiquituous features in disks around young stars. It is thought that they are signposts of ongoing planet formation. In our previous survey, CIDA 9 shows an asymmetric dust continuum ring with a shadow in the north side of our millimeter image. We propose continuum observations in Bands 3 and 4 to detect dust continuum shifts for different dust grain sizes. In the case of planet formation, the models predict that the dust continuum at all of the Bands will be cospatial. The presence of a deadzone can be seen through a radial shift in the continuum peak emission while it is an azimuthal shift in the case of a vortex. The requested molecular lines observations will also help in ruling out photoevaporation as the physical agent that forms the transition disk. The combined dust and gas observations proposed in this program can definitevely differentiate between photoevaporation, vortex, giant planet and dead zone. | Low-mass star formation | ISM and star formation | 2022-10-26T13:02:08.000 |
| 3156 | 2016.1.00229.S | 58 | Unveiling the Gas Phase Kinetic Chemistry in Protoplanetary Disks | ALMA images of CCH and C3H2 emission in two disks show clear evidence for an emission ring. These rings naturally arise in a disk where the ice-coated dust mass is spatially stratified with a surface and outer disk dominated by UV photons. We also esimtate that the C/O ratio is > 1 in this same gas with a rich kinetic chemistry. We propse to use ALMA to characterize this chemistry in TW Hya. (1) Using our chemical model as a guide we will search for the presence of additional hydrocarbons to characterize the extent of the chemistry. (2) Via observations of 13CCH we will measure that 12C/13C ratio which can provide clues to the source of carbon for the chemistry. (3) To obtain a deep observation of 13CO J = 2-1. These observations will be opitmized to detect and characterize the outer disk beyond the edge of the hydrocarbon emission ring which requires either a reduced total gas mass or total carbon. This gas has long been detected via 12CO emission and we aim to disciminate between these two scenarios. In all this program will characterize the active chemistry which is likely fundamental and evolving in all disk systems. | Astrochemistry | ISM and star formation | 2018-09-06T04:08:15.000 |
| 3157 | 2018.1.00763.S | 119 | HCN laser lines as beacons for highest resolution imaging | We propose to carry out a pilot search for hydrogen cyanide (HCN) laser emission lines near 805 and 891 GHz in carbon-rich evolved stars. HCN is one of the most abundant molecules in the envelopes of carbon-rich AGB stars and is produced efficiently in the regions very close to the stellar photosphere. Recent Band 5 survey by Menten et al. with APEX discovered widespread maser emission of vibrationally excited HCN at 177 GHz, offering a new way to study the dynamics of the inner winds of evolved stars by highly excited HCN transitions. Extremely intense submillimetre HCN laser emission near 805 and 891 GHz has thus far been searched and detected towards 2-3 carbon stars. The primary goal of our proposal is identify more carbon stars that exhibit HCN laser line emission. These lines will be the perfect beacons for self-calibration, which, in the future, will allow high-frequency, longest-baseline ALMA observations of compact line emission and, most importantly, the stellar photosphere at the angular resolution of ~5 mas, a scale that is crucial in understanding the physics of convection and pulsations in evolved stars' photosphere. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2020-08-07T00:00:00.000 |
| 3158 | 2023.1.01105.S | 0 | Detecting molecular gas in the giant low surface brighntess galaxy Malin 1 | We propose to detect 12CO(1-0) with band 3 in the iconic giant low surface brightness spiral galaxy Malin 1. Astonishingly, this galaxy has resisted CO detections for nearly 30 years, with the use of many instruments, including IRAM 30 m and recently, GBT 100 m. The situation represents a clear enigma, considering that this galaxy exhibits a huge disk of 200 kpc diameter, and has spots with Halpha and UV emission in the center and in some regions of the spiral arms, indicating the presence of active stellar formation and/or the presence of young stars. Using recent results appeared in the literature, which provide new upper limits for the surface mass density and probed an rms sensitivity of 0.1 K km/s, we propose to reach ten times more sensitivity with ALMA, but this time studying spots of 20 arcsec diameter where more likely the CO would be emitting. The proposed sensitivity is thus 0.01 K km/s with 3.5 arcsec resolution, and it is feasible in 7 hrs. Should these observations be positive, we would use ALMA in another opportunity with higher resolution to better characterize these regions. Also, it would be an opportunity to probe the same regions in other lines, like 12CO(3-2). | Spiral galaxies | Local Universe | 2025-03-30T18:32:14.000 |
| 3159 | 2016.1.00457.S | 45 | Physical and Chemical Transition from the Envelope to the Disk in the Hot Corino Source IRAS 16293-2422 | IRAS 16293-2422 is a well-studied Class 0 protostar, and is known as a typical hot corino harboring rich complex organic molecules (COMs) such as HCOOCH3. We have recently found an infalling-rotating envelope (IRE) in Source A of this source by analyzing the ALMA Cycle 1 archival data, and identified its centrifugal barrier with the aid of a simple ballistic model. A drastic chemical change is also found in this source: OCS traces the IRE, and CH3OH the centrifugal barrier, and H2CS the entire region from the envelope to the inner disk component. The Keplerian disk component is suggested by the high velocity component of the H2CS lines. However, the Keplerian rotation is not confirmed on the basis of the kinematic structure because of the limited resolution. To overcome this situation, we here propose higher angular resolution (0".07) observations to characterize the structure and dynamics of the Keplerian disk and the transition zone from the IRE to the Keplerian disk. These observations will address a long standing question how the disk structure is formed and what the hot corino is. Thus these observations have a substantial impact in astrochemistry and astrophysics. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-11-20T14:03:54.000 |
| 3160 | 2015.1.01086.S | 12 | Probing Disks around Massive Young Stellar Objects in Infrared Dark Cloud G53.2 | We propose the ALMA 350 GHz (Band 7) observations of high-mass young stellar objects (YSOs) in the infrared dark cloud (IRDC) G53.2 at ~1.7 kpc. We have recently found two YSOs in one of the IRDC G53.2 cores, which are likely driving remarkable H2 (2.12 micron) outflows. The H2 luminosity (>1.2 Lsun) and spectral energy distributions of the YSOs indicate that at least one of them is massive (M > 8 Msun), but the confirmation of the outflow-driving source is limited owing to the small separation (~8") between the YSOs and lower resolution in previous observations. The ALMA 350 GHz continuum observations with a resolution of ~0.5" of the proposed target will reveal its inner structure, which is expected to be an elongated filament composed of multiple dense cores as observed in other high-mass YSOs (e.g., G35.20-0.74N). Molecular lines in Band 7 will also trace dense gas, outflows, and hot cores so that we can directly probe circumstellar disks and molecular outflows around massive YSOs as well as figure out the H2 outflow-driving source. In addition, the proposed observations will provide some implications on high-mass star formation process occurring in IRDC cores in general. | High-mass star formation | ISM and star formation | 2017-10-11T22:07:26.000 |
| 3161 | 2019.2.00167.S | 307 | Grain growth in the youngest protostellar envelopes: the pristine properties of star and planet-forming material | We aim to tackle the long-standing problem of growth from micrometric ISM grains to millimeter pebbles, a crucial step towards the formation of planets in circumstellar disks. Using PdBI observations of the millimeter dust emission in a sample of 12 Class 0 protostars, we showed that dust grain growth seems to have significantly progressed in the interiors of these young (a fraction of a million years old) objects, which is at odds with current planet formation models. Our high-resolution PdBI and ALMA observations do not allow us, however, to probe the pristine dust properties in the outer envelopes, nor to reconnect to the dust sitting in the parenting filament. We have obtained multi-wavelength single-dish observations of the dust continuum emission to probe the dust at the filament-to-envelope scales. We request ACA observations of the dust continuum emission in 4 bands to constrain the dust emissivity index at envelope scales, bridging the gap between the dust observed at small envelope radii and the local dust reservoir that built cores out of filaments. | Low-mass star formation | ISM and star formation | 2022-10-04T11:59:02.000 |
| 3162 | 2017.1.00316.S | 14 | Searching for Submillimeter Water Megamaser Emissions from a High-z Lensed Quasar | We propose to search for the 336 GHz and 380 GHz water maser lines from the high redshift (z = 2.639) lensed quasar MG J0414+0534. With the aid of the gravitational lensing effect, the 22 GHz water maser line has been first detected from this quasar in 2008. However, due to the weakness of the line (~< 3 mJy) plus strong radio continuum (~500 mJy), the follow-up high-resolution imaging of the maser line with VLBI has not yet been successfully achieved due to continuum subtraction errors. In order to use water masers for studying AGN physics and probing cosmology, stronger maser lines are needed. Based on theoretical modeling, the water maser line at 380 GHz is expected to be significantly stronger than the 22 GHz line and therefore we aim to search for this line from the high-z quasar with ALMA and explore its applications to solve important astrophysical problems. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-01-12T16:59:36.000 |
| 3163 | 2017.1.01259.S | 124 | Identifying z~6 passive galaxies: relics of first galaxies at z~20 | We here propose an ALMA follow-up of candidate passive galaxies at z ~ 6 identified in our recent work (Mawatari et al. 2017, in prep). Since such highest-z passive galaxies should formed their stars at much higher redshift, their number density can provide a meaningful constraint on the star-formation rate density (SFRD) at z > 10. Our SED fitting analysis using very deep photometry from optical to far infrared wavelengths (0.4 - 500um), however, suggested two possibile populations for these objects: (1)passive galaxes (age~0.7Gyr, SFR=0, and no dust) at z~6, and (2)dusty star-forming galaxy (Av~4) at z~3. It is very important to separate these two populations of galaxies in our sample. Deep ALMA Band 7 observation for dust continuum will provide the only clue to distinguish whether the target galaxies are in passive or dusty star-forming phase. We request 13 hours observing time with Band 7, which can definitively reject the possibility that the targets are dusty star-forming galaxies at z~3 and will enable us to put a robust constraint on the SFRD in the very early Universe. | Starburst galaxies | Active galaxies | 2019-12-15T03:57:48.000 |
| 3164 | 2013.1.01010.S | 4 | The far-infared [OIII] line emissivity of high-z low-metallicity galaxies | Herschel observations of nearby low-metallicity dwarf galaxies have shown that the [OIII] 88 micron line tends to be stronger than the [CII] 158 micron line, while the opposite is true for normal spiral galaxies at about solar metallicity. If this holds true also for the high-redshift Universe, the [OIII] 88 micron line from z=6--7 star-forming galaxies, which are expected to have sub-solar metallicities, should be detectable with ALMA in a few hours of integration time. Here, we propose ALMA observations of two spectroscopically confirmed z~6--7 galaxies to make the first [OIII] measurements for objects in the reionization epoch. The measured [OIII]-to-[CII] flux ratios will also allow us to study the metallicity and other physical conditions in the interstellar medium of these high-z galaxies. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2015-11-27T11:39:12.000 |
| 3165 | 2012.1.00934.S | 0 | Molecular gas and star formation in 'normal' galaxies at z=2.23 | We propose observations of the CO molecular line emission from five star-forming galaxies at z=2.23, selected to be 'typical' star-forming galaxies seen at the epoch when cosmic star formation activity peaked. Molecular gas observations offer a unique view of the fuel that drives the star formation activity in galaxies. In the past decade considerable effort has been invested to characterise the mass, properties and dynamics of the molecular gas in distant galaxies, and to compare these gas-rich systems with local analogues. To date, however, only samples of high stellar mass systems have been studied. Using our HiZELS H-alpha survey we have selected a sample of galaxies with star formation rates at the characteristic luminosity, in a manner independent of stellar mass, within the CANDELS-UDS field. The stellar masses of these galaxies are up to an order of magnitude lower than those of high-redshift galaxy samples previously studied in molecular gas, thus opening up new parameter space. In this proposal we aim to: (i) determine the mass of molecular gas in these galaxies, the location on the Schmidt-Kennicutt relation, and the associated star formation efficiency; (ii) determine the gas phase distribution of the molecular gas, using brightness temperature ratios between different CO transitions; (iii) measure the dust continuum emission to provide an alternative far-IR-based estimate of the star-formation rate of the galaxies. The results will be directly compared with existing data on more massive counterparts at the same star-formation rate (SFR), and more luminous sub-mm galaxies at the same specific star formation rate (SFR/M*). | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2015-06-20T13:51:00.000 |
| 3166 | 2018.1.01717.S | 54 | Zooming in on the core emission of quasars | It remains an open question what produces the mm-radio emission in radio quiet quasars; with star formation, quasar winds, jets, and accretion disc corona all proposed. Furthermore an observed relationship between outflows and radio emission has important implications for feedback. We have been studying the spatially-resolved gas kinematics and radio emission in a sample of 10 z<0.2 quasars. To date we have found kpc scale ionized gas outflows and kpc radio jets in >70%. However we are only sensitive to morphologies on kpc scales, leaving ~1/2 of the total flux in unresolved cores. In this pilot study, we will use high angular resolution (0.06" = ~100 pc) band 3 continuum imaging of 3 targets that span the range of ~kpc scale morphologies observed. We will establish if the emission is: 1) compact on <50pc scales, supporting the corona hypothesis, 2) in elongated ~150pc jets as seen in some lower power AGN, or 3) in diffuse ~200pc structures. These observations will be able to provide constraints on the launching mechanism of the observed outflows, investigate the source of 100GHz emission in quasars, and provide a test case for future high resolution mm imaging of quasars. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2020-10-24T21:28:13.000 |
| 3167 | 2018.1.00047.S | 179 | Monitor band-6 line variability in IRC +10216 with ALMA Compact Array (III). | AGB stellar wind is an important phenomenon. The AGB wind acceleration regions are too small and obscured to be easily observed. The recently discovered mm line variability in the archetypal carbon star IRC +10216 has offered the opportunity to explore the AGB wind acceleration in a dynamical view. Our ALMA/ACA Cycle 4 and 5 monitoring of IRC +10216 at 1.3 mm has covered about 1/2 of the 630 day pulsation period of this star up to this moment. The preliminary results have confirmed the regular variations of many lines and has revealed rich novel variation patterns. We propose to continue the monitoring into Cycle 6 to (1) remedy the bad temporal sampling in Cycle 4; (2) cover about two full pulsation periods to check the periodicity of the interesting light curve patterns and to yield more reliable light-curve parameters to differentiate different variation mechanisms. This proposal will serve as a basis for further time dependent explorations of the wind acceleration region of this star at higher spatial resolutions (see our two companion Cycle-6 projects 2018.1.00048.S and 2018.1.00263.S). | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2019-11-30T09:16:57.000 |
| 3168 | 2023.1.01675.S | 0 | Reveal the 10~au scale substructures in two protostellar disks | Small-scale substructures, including spiral arms and misaligned/wrapped inner disk, have been found in cirumstellar disks around low-mass protostars when they are still in a disk forming phase (Class 0/I). To study these substructures is important for our understanding of star/planet formation and origin of multiplicity. In the intermediate mass star forming region NGC2071IR, we have identified two sources (IRS1, IRS3) with strong evidence of disk substructures at a few 10AU scale. IRS1 is an intermediate mass protostellar system (3Msun | Intermediate-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3169 | 2015.1.00256.S | 42 | The massive, fast-bipolar outflow of the extreme AGB star OH 231.8+4.2 | One striking aspect of the late evolution of Sun-like stars is the change of nebular morphology in the transition from the asymptotic giant branch (AGB) to the planetary nebula (PN) phase. On the AGB, the stellar mass loss is roughly spherically symmetric, but this rapidly evolves into prominent non-spherical morphologies in the pre-PN phase. We propose to map with unprecedented angular resolution (0.2") and sensitivity the bipolar outflow around the extreme AGB star OH231.8+4.2, where the effects of the recent collision between underlying jets and the dense AGB wind are notable. We request a 5-point mosaic of the 12COJ=3-2 (and, simultaneously, 13COJ=3-2 and CSJ=7-6) emission, and one single-pointed map of the CS J=6-5 line. We aim at constraining the mass and temperature stratification, and the velocity field along and across the lobes. CO transitions are the best tracers of the bulk of the envelope (predominatly cold, 10-40K). CS J=6-5 selectively traces warm (200K) gas recently discovered.This is a resubmission of proposal 2013.1.00252.S, ranked in the 10-20% band of all cycle 2 proposals. Observations are in progress (12% completed) but unlikely to be finished in cycle 2. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-01-12T01:39:49.000 |
| 3170 | 2013.1.00965.S | 4 | Fast outflows quenching star formation at high redshift | According to theoretical models, quasar driven outflows at high redshift clean massive galaxies of their gas content and quench star formation. We have recently discovered powerful AGN-driven outflows by studying the velocity field of [OIII]5007 in two quasars at z~2.4. The spatial distribution of the starforming regions in their host galaxies is anticorrelated with the presence of fast outflows, providing the very first evidence of quasar feedback quenching star formation. However, this evidence is tentative as it is based only on rest-frame optical spectra. We propose to map CO(3-2) to trace the distribution of the cold molecular gas in the two quasars, the only ones known so far showing evidence of outflows quenching star formation. The CO(3-2) maps will be compared with our [OIII] maps with similar spatial resolution: the molecular gas should be absent in the outflow dominated region, while surviving in the rest of the galaxy. This would be the first direct confirmation of star formation quenching by quasar outflows. Our ALMA observations will then open the way for the physical characterization of quasar driven feedback in larger samples of objects. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2016-08-12T11:25:55.000 |
| 3171 | 2015.1.00851.S | 11 | Cold gas in a cosmic `Spiderweb' of proto-galaxies: witnessing the in-situ birth of a giant cluster elliptical? | The largest galaxies in the Universe are giant ellipticals in the cores of galaxy clusters. Simulations predict that their early evolutionary stages (in proto-clusters at z>1) are dominated by rapid gas cooling that triggers "in-situ" star-formation. Using ATCA and VLA, we have obtained the first tantalizing observational evidence for this scenario, by detecting and resolving an extended (~80 kpc) reservoir of cold molecular CO(1-0) gas in the massive `Spiderweb' radio galaxy at z=2.2. The Spiderweb Galaxy is embedded in a rich proto-cluster and surrounded by a UV-emitting halo that harbors widespread star formation. For the first time, we identified the fuel reservoir that can sustain such widespread star formation. We here propose ALMA observations of [CI](1-0), CO(4-3) and the 600 micron dust to study the physical and chemical properties of the cold IGM across the halo. This will allow us to better understand the nature, origin and evolutionary role of the cold proto-cluster IGM. It may ultimately test theoretical predictions of how gas cooling deep inside the potential wells of high-z proto-clusters shapes the early formation of the most massive galaxies in the Universe. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-03-15T19:15:53.000 |
| 3172 | 2022.1.01493.S | 30 | Ionized islands in a neutral Universe: constraining early galaxy evolution through "reionized bubbles" | A recent advancement in the exploration of the epoch of reionization has been the discovery of candidate "reionized bubbles", i.e. regions where reionization likely started earlier or proceeded faster. These regions provide the best opportunity to shed light on the physical mechanisms governing reionization and early galaxy evolution. The present proposal will observe 11 galaxies within the only two regions accessible by ALMA: the "COSMOS bubble" at z~6.8 (Endsley+21,+22), and the "BDF bubble" at z~7 (Castellano+16,+18). We will observe 8 confirmed members, plus 3 sources with robust photometric redshifts indicating they are most probably located in the bubbles. ALMA band 6 will target the [CII] spectral region reaching a depth enabling also the detection of the dust continuum emission. The requested observations will 1) firmly constrain the ionization state of the regions through the measurement of systemic redshifts and Lya offsets; and 2) obtain an unbiased census of the SFR and dust properties of their members which will be compared to available observations of similar galaxies outside the overdensities to shed light on environmental effects in the early Universe. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-09-20T14:42:29.000 |
| 3173 | 2019.1.00041.S | 0 | Searching for the magnetic field in the Beta Pic debris disk | We aim to make the first-ever detection of submillimeter dust polarization in a debris disk by observing the bright, iconic source Beta Pic in order to infer the morphology and strength of the magnetic field in this planet-forming system. Confirming the presence of magnetic fields in debris disks is essential, as the field may play a key role in the gas transport and evolution of these important objects. Over the last several years, 870 micron ALMA polarization observations of protoplanetary and transition disks have yielded a wide variety of results, most of which have pointed to polarization from self-scattering by dust grains. This has made it impossible, thus far, to use dust polarization to infer confidently the magnetic field morphology in a circumstellar disk. The main reason self-scattering dominates at submillimeter wavelengths is because many disks are (very or marginally) optically thick, and the degree of the scattering-induced polarization increases linearly with the dust optical depth. Thus, to avoid contamination from scattering, it makes sense to observe a disk with the lowest possible optical depth: i.e., a debris disk. | Debris disks, Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 3174 | 2023.1.01435.S | 27 | First step for a systematic study of the molecular gas in interacting galaxies at every evolutionary stage | We propose to measure the 12CO(2-1) and 13CO(2-1) lines of 8 interacting systems to reveal the variations of molecular gas properties on kiloparsec scales during the merging process. From the resolved 12CO(1-0) and 13CO(1-0) mapping survey EDGE-CALIFA, we select the 8 less-luminous interacting galaxies that are at different merging stages. We aim to focus on the changes of physical condition of molecular gas that are mostly likely due to the interacting process for the selected samples. Combining 12CO(2-1) and 13CO(2-1) with the archival 1-0 observations from the EDGE-CALIFA, we will constrain the density, temperature, and/or isotopologue abundance of the proposed targets on kiloparsec scales. We will also study the relations of molecular gas conditions to stellar and ionized gas properties at every merging stages, using the ancillary resolved optical IFU data from EDGE-CALIFA. This study will be the first step for a systematic study of the molecular gas in interacting galaxies to obtain a comprehensive picture of the merging process. | Merging and interacting galaxies | Galaxy evolution | 2025-06-12T17:29:40.000 |
| 3175 | 2015.1.01014.S | 48 | What can hubs tell us on massive star formation? | Despite the importance of massive stars in galaxy evolution, the process through which their progenitors are built remains highly controversial. Our ALMA cycle 0 results showed that one of the most massive cores ever observed in the Galaxy is forming at the converging point of a network of dense filaments, or hub. The data suggest that the large infall rate required to form this core is powered by the global collapse of the cloud. Here we propose to perform a first test of the universality of this scenario by mapping the fragmentation and kinematics of 5 massive infrared dark hubs with the objective of determining what key properties of the parental clouds determine the mass of the most massive cores. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-08-12T14:08:45.000 |
| 3176 | 2019.1.01720.S | 63 | The quest for bona fide hot cores in the Large Magellanic Cloud | One of the most important goals of astrochemistry is to understand the origin and evolution of complex organic molecules (COMs). Rich interstellar COMs might have been delivered to the early Earth, providing important ingredients needed for the origin of life. The Large Magellanic Cloud (LMC) is the nearest laboratory for detailed studies on the formation and survival of COMs under metal poor conditions, typical for the early universe. To date, only two sources with the hot core complex chemistry have been identified in the LMC, limiting our ability to draw firm conclusions. We propose Band 6 observations aimed to identify and characterize bona fide hot cores in the LMC by observing carefully selected candidates that have common characteristics with the only known extragalactic hot cores with organics in the star-forming region N113: they are found in the vicinity of massive YSOs and are associated with water/OH masers and the SO emission, the well-known hot core tracer. With an increased sample of hot cores, we will be able to make a step forward toward the understanding the impact of metallicity on complex organic chemistry. | High-mass star formation | ISM and star formation | 2021-02-25T22:11:34.000 |
| 3177 | 2024.1.00216.S | 0 | Timing the Onset of Unexpected Dust Destruction using High-Redshift Post-Starburst Galaxies | ALMA observations of the submillimeter dust continuum are now in wide use to measure cold gas masses at early cosmic times. This method relies on an assumed molecular gas-to-dust ratio, with a value =100 typically used. However, recent theoretical work finds that dust is preferentially destroyed as galaxies transition to quiescence, resulting in gas-to-dust ratios >1000 and enormous scatter. Recent ALMA observations seem to confirm this picture, with a sample of old z~0.7 quiescent galaxies displaying gas-to-dust ratios >500-1500. We now must understand whether this unexpected dust destruction applies only to old quiescent galaxies or also to newly-quenched objects that may even be only temporarily quiescent. We propose to measure the timescale for dust destruction using a sample of 19 recently-quenched galaxies with existing CO detections at the same epoch. Our dust continuum observations will reach 3sigma lower limits on the gas-to-dust ratio of 500-1000 in individual sources, which will test whether dust destruction post-quenching occurs rapidly or slowly. The results of this study could have wide-reaching consequences for current and future ALMA continuum observations. | Galaxy structure & evolution | Galaxy evolution | 2025-10-16T04:43:47.000 |
| 3178 | 2017.1.00661.S | 103 | Testing predictions of stellar cluster formation in NGC6334I | Our Cycle 2 and 3 studies of the nearby (1.3kpc) massive embedded protocluster NGC6334I have yielded remarkable results, including the discovery of numerous high and low mass protostars actively accreting and driving outflows within the central 0.1pc, and an accretion outburst from a massive protostar (MM1B). In order to test the predictions of stellar cluster formation models, we seek to expand our survey area (by 5 times) to fully cover the protocluster, and to improve the sensitivity (by 2 times). These data will allow us to obtain a census of the protostellar activity in this region down to a gas mass limit of ~0.02 Msun. By observing with matched angular resolution (260 au) at 2.2 and 1.0mm, we will be able to measure the size and spectral index to constrain the nature of each object, as well as their distribution across the cluster. We will also determine which sources are actively accreting by searching for outflows in multiple molecular tracers, include two transitions of SiO (3-2 & 7-6), in order to probe outflowing gas across a range of excitation conditions. These data will also constrain the decay timescale and accretion rate of the extraordinary outburst from MM1B. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2019-02-14T05:52:40.000 |
| 3179 | 2022.1.00446.S | 40 | Tracing Neutral Star-Forming Gas in the EoR using the [OI]-145um emission line | We propose to observe the [OI]145um emission line of 4 recently discovered, [CII]-luminous, normal star-forming galaxies in the epoch of reionization (EoR) at z>6.5. Having a similar ionization potential as that of hydrogen, neutral oxygen is an ideal tracer of neutral star-forming gas. Recent studies revealed luminous [OI]145um emission lines in high-redshift SMGs and QSO hosts at z=4-7.5, suggesting the presence of abundant dense neutral gas in these extreme starbursts. However, no observation has been done for normal galaxies in the EoR, for which we still only have a very crude handle on the neutral ISM properties. The proposed observations represent a first pilot survey of [OI]145um emission targeting [CII]-luminous sources in the EoR. We will achieve the following: (1) [OI]/[CII] line ratio of normal, star-forming galaxies in the EoR (2) spatial extention of the neutral ISM (3) model ionized and photodissiciation gas. By selecting the most [CII]-luminous galaxies, our proposed program can efficiently cover the expected range of [OI]/[CII] line ratios. This observation will uniquely open a new window to study the neutral gas reservoirs in the EoR. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-12-26T00:00:00.000 |
| 3180 | 2016.1.00646.S | 422 | Galaxies' Gas Supply in Two Massive, Starbursting Galaxy Cluster Progenitors at z>2 | The identification of distant (z>2) protoclusters has primarily focused on detection of faint Lyman-break galaxies (LBGs) around 1-3 bright radio-loud quasars or dusty starbursts. It is yet unknown how the lower-luminosity galaxies at these early epochs contribute to the growth of such massive structures. Are they growing at elevated rates with respect to similar galaxies in less dense environments? Or is their growth rate similar or quenched with respect to the field? Current results are mixed, with some claiming a reversal in the SFR-density relation at high-z and others claiming no difference. The crucial missing part of the puzzle are those galaxies' gas supply, or potential for future star-formation, and the implications of such gas reservoirs on the star-formation histories of early protocluster LBGs. Here we propose to observe 65 spectroscopically-confirmed LBGs in two overlapping protoclusters at z=2.10 and z=2.47 in the COSMOS field. These dust continuum observations will allow us to constrain ISM masses, thus gas masses. We will use those gas masses to study the star-formation efficiency of galaxies in overdensities and compare with control LBGs in the field. | Lyman Break Galaxies (LBG), Galaxy Clusters | Galaxy evolution | 2018-06-13T21:00:18.000 |
| 3181 | 2021.1.01477.S | 18 | A complete map of Atomic Carbon (C I): the key to the evolution of gas in debris disks | The recent discoveries of exocometary gas in debris disks have enabled observations of volatiles during the latest stages of terrestrial planet formation, when cometary impacts and late gas accretion may affect exoplanetary atmospheres. A key quantity needed to understand the evolution of exocometary gas is the CO photodissociation timescale, which crucially depends on the level of shielding, and therefore the vertical column density, of its photodissociation product neutral atomic carbon (C I). We propose high resolution (47 mas) Band 8 observations of the C I 3P1-3P0 line, combined with lower resolution (0.2") Band 10 observations of the 12C I and 13C I 3P2-3P1 lines, within the gas-bearing debris disk around the 15-30 Myr-old star HD32297. These measurements will break the degeneracy between the vertical structure, excitation/optical depth and mass of C I that currently prevent single-line measurements from uniquely determining the its column density, and therefore its shielding efficiency. These data will allow a first direct probe of the CO photodissociation timescale, the key to understand the origin and dynamical evolution of exocometary gas in shielded debris disks. | Debris disks, Disks around high-mass stars | Disks and planet formation | 2022-11-30T23:12:33.000 |
| 3182 | 2018.1.01237.S | 20 | Pinning down the CO snowline in the multigapped disk of HD 169142 | Snowlines in protoplanetary disks are thought to have important effects on dust evolution, which will in turn impact planetary formation. Recently, our group reported VLA and ALMA observations of the multigapped disk of HD 169142 and tentatively detected an annular ring of dust emission that seemed to be associated with the CO snowline. Following observations at other wavelengths also suggest the presence of this ring. We request new ALMA observations in order to accurately measure the location of the CO snowline in the HD 169142 disk. We plan to observe the N2H+(3-2) transition, which has been shown to be a good tracer of the CO snowline. These data will allow us to prove whether the location of the snowline is coincident with the observed dust ring. Our observations could represent the first direct evidence of halting and accumulation of large dust grains at the position of a snowline. The confirmation of this scenario would provide us with a key piece to understand the process of dust growth and planet formation in protoplanetary disks. This is a resubmission of an approved Cycle 5 proposal that has not been observed yet. | Disks around low-mass stars | Disks and planet formation | 2020-08-17T05:28:10.000 |
| 3183 | 2019.1.00467.S | 0 | Using Hourglass Field Morphologies to Directly Estimate Magnetic Field Strengths | Toward dense protostellar envelopes, hourglass magnetic field morphologies are found at the ~1000 AU scale, and these structures imply flux-freezing during collapse. The Davis-Chandrasekhar-Fermi technique is typically used to estimate the field strength, where astronomers subtract a fit and estimate the magnetic field from the residuals, i.e., from the disordered component of the fit. We have derived a way to calculate the magnetic field strength directly from the ordered component by assuming flux freezing during collapse. We will utilize this new technique by observing Band 6 polarization toward 4 protostars with known global hourglass morphologies. These observations will be more sensitive and have superior resolution to any hourglass polarization map, and will map each field over >100 beams to robustly capture the global field structure. We will use our technique to estimate the field strength and mass to flux ratios throughout each source, which allows us to understand where the fields set the mass accretion rate toward the protostar and its disk. We will also observe the protostellar outflows with CO (2-1) to determine how they may affect our model. | Low-mass star formation | ISM and star formation | 2021-07-20T22:06:13.000 |
| 3184 | 2013.1.01042.S | 4 | Revealing the Physical Properties of Molecular Gas Associated with the Magellanic SNR N132D | In supernova remnants (SNRs), the interaction between the shock waves and the ambient interstellar gas is an essential process which affects evolution, high-energy emission, and relativistic particle acceleration. Therefore, it is important to study the detailed physical properties of the interaction between SNRs and interstellar gas, in order to understand the underlying processes. N132D is the brightest SNR in the Large Magellanic Cloud (LMC) and is thought to be associated with the molecular clouds. Most recently, we found the interacting molecular gas by using the Mopra 12CO(J=1-0) dataset. However, we could not reveal the detailed structures and the physical conditions. We propose to observe N132D and its surroundings with 12CO(J=1-0) line emission by ALMA and to determine the physical properties of molecular clouds interacting with the shock waves. ALMA's sensitivity and spatial resolution will allow us to study in detail the CO gas interacting with the "extragalactic SNR" for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2016-03-24T20:28:04.000 |
| 3185 | 2015.1.00944.S | 39 | Chemical Composition of Molecular Clouds in Nearby Low-metallicity Galaxy NGC 55 | In metal-poor environments, chemical compositions of molecular clouds are different from that in our Galaxy. Based on our recent observations of the two low-metallicity galaxies, the LMC and IC 10, with the Mopra 22 m telescope, we recently found characteristic features of chemical compositions in metal-poor conditions. Those are enhancement of CCH and deficiency of CH3OH, which are both caused by the low abundance of dust grains. This proposal aims at extending our study to NGC 55, which has lower metallicity than in the LMC and IC 10. NGC 55 is a nearby galaxy (d~2 Mpc, 12+log(O/H)~8.0), and is bright at 8 micron. However, no molecular emissions except for the 12CO and 13CO emission has been detected so far, because of insufficient sensitivity of the single-dish telescope. We will observe the lines of CCH, HCN, HCO+, HNC, CH3OH, CS, SO, C18O, and 13CO in the 3 mm band, and confirm the above chemical trend. This source has the lowest metallicity among nearby galaxies targeted by astrochemical observations, and the observation can only be done with ALMA. | Galaxy chemistry, Dwarf/metal-poor galaxies | Galaxy evolution | 2018-04-12T00:06:15.000 |
| 3186 | 2017.1.01406.S | 133 | A Quest for Cosmic Ray Acceleration Site: Unveiling the Shock-Cloud Interaction toward the Young SNR RX J1713.7-3946 | In supernova remnants (SNRs), interaction between the shock waves and surrounding interstellar gas plays an essential role in understanding the magnetic field amplification and efficient acceleration of cosmic rays. The SNR RX J1713.7-3946 is bright in synchrotron X-rays which are produced by ultrarelativistic electrons. The acceleration of this population takes place in a strongly magnetized medium that experiences amplification of the magnetic field up to 1 mG via shock-cloud interaction. Recently, we found tiny CO clumps toward the northwest of the SNR, which are clearly rim-brightened in X-rays. We concluded that the shock-cloud interaction enhances turbulence and magnetic field around the CO clumps in a pc scale. However, the spatial resolution of current CO data (~0.22 pc) is not high enough to compare with the X-ray filaments of ~0.05 pc width. We propose to observe the CO(1-0) with 0.015 pc resolution by using ALMA band 3 in order to reveal a physical connection between the CO clumps and synchrotron X-ray filaments. ALMA's unprecedented sensitivity and spatial resolution will allow us to study molecular clumps interacting with the SNR in a 0.01 pc scale for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-07-26T00:00:00.000 |
| 3187 | 2015.1.01157.S | 41 | ALLO: ALMA Lensed Line Observations | We request 4.4 hours of ALMA time to observe [CI] (2-1), [CI](1-0) and CO (7-6) lines in 2 extremely lensed, but otherwise typical star-forming galaxies at redshifts z=2-3. These galaxies are part of our survey of [CII](158 micron) and [OI] (63 micron) lines with Herschel (the Herschel Extreme Lensing Line Observations 'HELLO'). The HELLO sample of normal galaxies forms an ideal complement to studies of dusty starbursts at z=2. By themselves, the two [CI] lines will enable determination of excitation temperatures, neutral C column density and mass independent of any other measurements. Combined with the Herschel [CII] line measurements, the [CI] and CO lines will give a complete picture of the physical conditions, including density, far-ultraviolet flux, temperature, and pressures in atomic and molecular gas. With the [CII], [OI], [CI], and multiple CO lines we will have the total cooling budget and we can determine whether their ISM at z=2 is fundamentally different from the local universe. ALMA's spatial resolution will also allow a study of spatially resolved kinematics of these galaxies, among which some show outflows and some show cold rotation. | Starbursts, star formation | Active galaxies | 2017-09-09T15:47:47.000 |
| 3188 | 2019.1.00730.S | 60 | The cold ISM in nearby analogs of cosmic reionization sources | We propose to measure the molecular gas content in a sample of z~0.3 Lyman continuum emitting galaxies we have recently discovered with the HST. These galaxies are compact, highly star-forming galaxies with strong optical emission lines, which resemble «green peas» and luminous compact galaxies. These rare at low-z galaxies are currently the best nearby analogs of the sources of cosmic reionization. The proposed CO(3-2) observations will inform us for the first time about the molecular gas properties of these unique and extremely interesting sources. We will determine the total molecular gas mass and column density, gas fraction, molecular gas depletion time scales, and aim at constraining kinematics of the cold gas. This will allow us to address key questions on their ISM properties, the gas consumption times, and the feedback processes allowing the escape of ionizing radiation. The properties of the Lyman continuum emitting galaxies will also be compared to those of normal and dwarf galaxies at z~0-3. Our observations will provide important insights for the ISM in these galaxies, and pave the way for understanding how similar galaxies can reionize the Universe at early epochs. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2022-04-09T16:07:11.000 |
| 3189 | 2017.1.01101.S | 36 | Are GMCs Real? Searching for the physical objects in a multiscale ISM | We propose fully-sampled observations of 12CO/13CO/C18O(2-1) of a 5 kpc-square box in NGC253, probing scales from 5 pc to 5000 pc. These observations will allow us to search for the signatures of bound molecular clouds in the ISM on a wide range of scales around the canonical cloud size of 50 pc. Identifying such a preferred scale will prove the view that Giant Molecular Clouds are well defined entities, but the lack of such a scale would support the view that what we observe as GMCs are just part of a larger hierarchical ISM and should not be regarded as real objects. We will use a dendrogram-based measure of the gravitational binding on a full range of scales to isolate this signature. We will also measure the properties of turbulence and angular momentum using techniques drawn from the literature. The observations will join a small number of complementary, archival data sets of sufficient quality for multiscale analysis. This will enable a robust, three-dimensional view of the molecular ISM. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2020-03-15T00:00:00.000 |
| 3190 | 2015.1.00748.S | 39 | Molecules in SN 1987A - probing the chemistry and nucleosynthesis | Our Cycle 0 observations discovered strong broad CO line emission from SN 1987A (Kamenetzky et al. 2013). Our Cycle 2 observations, which have so far covered part of Band 6, confirmed very strong broad SiO emission and produced probable detections of HCO+ and SO. We propose a new spectral survey of the 90-150 GHz spectrum of SN 1987A, along with coverage of a few selected Band 7 regions, all at 0.3 arscec resolution. The aim is to unambiguously measure at least two to three lines from each species, enabling density and temperatures to be estimated and the chemical processes in play to be diagnosed. The survey will include lines of 29SiO, 30SiO and 13CO, enabling isotope ratios, or upper limits, to be measured for a supernova for the first time, diagnosing nucleosynthetic processes. We found CO and SiO to to have different line profiles, implying different spatial distributions for these two species; our proposed observations should yield profiles for further molecules. Our total time request including calibrations is 6.3hr. | Supernovae (SN) ejecta | Stars and stellar evolution | 2018-03-15T15:52:30.000 |
| 3191 | 2016.1.01090.S | 38 | The molecular gas environs of dusty radio galaxies at z~2 | We propose Band 3 and 6 observations to target 12CO J=3-2 and J=7-6 in two radio galaxies at z~2. Our targets have been selected from the H-ATLAS / GAMA fields, and are known to harbour both an AGN, a ~1000 M_sol / yr star formation event, and ~10^9 M_sol of dust, similar to the most massive sub-mm galaxies. The systems are optically faint and have radio luminosities close to the knee of the luminosity function. They are therefore representative of `typical' high-z radio galaxies, however ground-state CO observations with the ATCA reveal exceptional quantities of molecular gas with a ~1000 km/s velocity spread in both targets. Our proposed high spatial and spectral resolution ALMA observations will determine whether the molecular gas is associated with a merger event, a (jet-driven) outflow or a massive disk, and facilitate dynamical modelling of the system. We will model the CO ladder to search for low/high excitation regions of gas in the halo/circumnuclear regions, and resolved continuum imaging will allow comparison between the regions of CO and redshifted dust emission. We also search for dense gas tracers HCN and HCO+ in one of the targets. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-04-27T22:17:43.000 |
| 3192 | 2024.1.00623.S | 0 | Molecular gas conditions and outflows in a quasar at redshift 6 probed by water vapor | Molecular gas is the primary fuel for star formation and accretion onto supermassive black holes. Despite its importance in galaxy evolution, molecular gas is still scarcely traced at high redshift (z>6) at the epoch of reionization. In particular, the properties of molecular outflows and physical conditions are not fully understood due to limited observations. We propose to conduct a line survey of H2O molecule toward J2054-0005, a luminous quasar that harbors the most powerful OH molecular outflow at z>6. Owing to the availability of rich auxiliary data (OH 119 um, [CII] 158 um, CO, dust), J2054-0005 is one of the best quasars for a case study. This is the first project that aims at investigating the gas conditions in a z>6 quasar with an OH outflow using a suite of 10 water vapor lines that probe excitation up to ~400 K. The main goals are to estimate 1) the molecular gas conditions by conducting radiative transfer modeling, 2) search for H2O in the OH outflow via absorption, and 3) study the outflow's impact on star formation. A detection of blue-shifted H2O absorption would be the first evidence of highly-excited molecular gas in an outflow from a quasar at high redshift. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 3000-01-01T00:00:00.000 |
| 3193 | 2022.1.00445.S | 378 | Revealing overdensities and early-stage mergers in the Submillimeter Galaxy population | Early theoretical works predict a population of early-stage mergers in overdense environments within the Submillimeter Galaxy (SMG) population. Nevertheless, the observational evidence for these interactions has been scarce, and the influence of the environment on their star formation process is still not fully understood. Combining large-area surveys carried out with Herschel with new ALMA and AzTEC imaging we have built a sample of 5 galaxy-pair SMGs candidates, which are likely early-stage mergers. Here, we request band 3 and band 4 observations to perform a blind spectral scan in order to: (1) confirm the nature of these systems and find new associated sources; (2) test the predictions of various theoretical works on the nature of the SMG population; and (3) characterize the star formation process during the earliest stages of galaxy interactions. This project will provide the first confirmed sample of early-stage mergers and reveal high-redshift protocluster structures rich in extreme star-forming galaxies, ultimately shedding light on the influence of the environment on the star formation process. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2024-01-09T18:51:09.000 |
| 3194 | 2012.1.01004.S | 2 | Evolution of molecular clouds in the superwind of the starburst galaxy NGC 1808 | We propose observations of the nearby starburst galaxy NGC 1808. The aim is to map the distribution of the molecular gas traced with the CO(J=1-0) line and dust, in order to study the molecular gas outflow (galactic superwind) in high resolution and sensitivity. The proposal addresses the energetics of the outflow, which can be derived from the outflow mass and velocity, and also the environmental effects in the galactic disk: the dynamics of giant molecular clouds in the unusually gas-rich bar, star formation in the central region and in the bar, as well as the fueling of the central region. Studying galactic superwinds is important for galaxy evolution because the major feedback of the starburst phenomenon is the enrichment of the intergalactic medium with heavy elements and star formation induced by shocks from large-scale winds of hot gas. The galaxy is a good target for our science goals and ALMA because of its moderate inclination and low declination. | Starbursts, star formation | Active galaxies | 2015-08-07T20:50:07.000 |
| 3195 | 2021.1.01441.S | 13 | Can cosmic rays drive outflows?: chemical diagnostics toward the nearest starburst NGC 253 | Galactic-scale outflows are an important mechanism to regulate star-formation in galaxies. However, the origins of such outward motions of gas are still unclear. One of the most promising but less understood mechanisms is cosmic-ray pressure gradients. While recently many theoretical studies have proposed that cosmic rays can trigger galactic-scale outflows, it is difficult to test it observationally because cosmic rays are not directly observable. Here, we propose to utilize the chemical diagnostics based on the abundance ratio of OH+ and H2O+, which has already been successfully applied to various sources, to investigate the potential role of cosmic rays in driving outflows. Our target is NGC 253, the nearest starburst galaxy accessible with ALMA. The enhanced cosmic-ray density reported by gamma-ray observations as well as its proximity makes it the best target to achieve our purpose. We will map OH+ and H2O+ in the CMZ of NGC 253 with ~3pc resolution and examine whether energy injections by cosmic rays are responsible for mass loading of molecular outflows. Our project will shed light on the potential role of cosmic rays in stellar feedback processes. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2023-10-11T06:29:01.000 |
| 3196 | 2019.1.00639.S | 34 | The Infrared Dark Cloud G034.77-00.55 and the first fully resolved interstellar magnetised shock | Infrared Dark Clouds (IRDCs) host the very initial conditions of high-mass star formation, but the mechanism that leads to its ignition within the clouds is still unclear. Low velocity (10 km/s) collisions of molecular gas flows have been suggested to efficiently gather together sufficient amounts of material in a relatively short timescale and hence trigger the formation of massive stars in IRDCs. Our group has detected a large-scale converging molecular flow and/or collision driven by a nearby Supernova Remnant (SNR) toward IRDC G034.77-00.55 by means of narrow and widespread Silicon Monoxide (SiO) emission (Cosentino et al. 2018). We have mapped the same SiO emission with ALMA and have detected, for the first time, the fully resolved kinematic structure of a CJ-type shock associated with such an interaction. Here, we propose to use the unique capabilities of ALMA to observe mid and high-J CO rotational transitions toward the IRDC G034.77-00.55 to further investigate the physical conditions of the gas in the C and J-type components of the observed shock and to provide an observational test of interstellar shock theories. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-10-19T22:08:27.000 |
| 3197 | 2012.1.00335.S | 3 | CO observations covering the entire N55, the best example of stochastic self-propagating star formation, in Super Giant Shell 4 in the LMC | We propose an ALMA observation of molecular gas toward N55 in the LMC. N55 is located in the Super Giant Shell 4, and is a cometary-shaped cloud that is thought to be affected by supernova explosions. The Spitzer/Herschel images show peculiar features in this region; there are a lot of filaments and clumps entangled with a size scale of a few pc, and then this structure may be formed by an effect of shocks from the supernova explosions. The Spitzer/Herschel data also show that many YSOs are distributed inside N55, indicating that the star formation is on-going. We observed molecular gas in N55 by using ASTE in the J=3-2 lines of 12CO and 13CO with an angular resolution of 23 arcsec. One of the CO peaks with a luminous YSO is a position where infrared filaments seem to be merging, and then there is a possibility that star formation has been by the filament merging. We found that with the ALMA + ACA array we can cover a whole molecular gas distribution of a GMC in Band-3 in the LMC without losing information on extended emission. In the present proposal, we then make mosaic observations of the entire cloud covering as large as 224”x387” area, corresponding to 90pc x 50pc, in the lines of 13CO(1-0), C18O(1-0), CS(2-1) and H40alpha by using the ALMA with the ACA array (7m + TP) with a final angular resolution of a few arcsec, corresponding to a spatial resolution of ~0.6 pc. This type of observations can be achieved for the first time during the Cycle 1, and then our knowledge of the GMCs in the external galaxy will be greatly improved. With this observation, we aim to resolve the filamentary structures and clumps with precise velocity information to be compared with the data of Spitzer-SAGE and Herschel-HERITAGE, and with simulations. This study will enable us to derive detailed physical properties of the possibly induced star forming GMC, leading to an understanding of the formation mechanism of highly filamentary structures and eventually of the role of the supernova explosions on the dense core and star formation. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2021-03-16T00:00:00.000 |
| 3198 | 2019.1.01406.T | 10 | The properties of compact-object mergers detected by LIGO and VIRGO | With the discovery of the binary neutron star merger gravitational-wave (GW) source GW170817, and its electromagnetic counterpart, the era of GW+EM multi-messenger astronomy has truly begun. The combined power of the LIGO and the VIRGO GW detectors led to a rapid localisation in the range of several dozen square degrees, combined with the distance information as a third dimension. This allowed the discovery of a kilonova (KN) associated with the merger event, and thereby a precise localisation and distance measurement. While the optical emission traces the radioactive merger ejecta powering the KN, emission in the radio domain traces relativistic ejecta associated with the accompanying gamma-ray burst (GRB). We propose to follow up compact-object mergers with ALMA. Our goals are to 1) determine the range of electromagnetic properties seen in compact-object mergers, 2) establish how properties of the electromagnetic counterparts depend on the system parameters and viewing angle, which can also be important to break degeneracies in the GW analysis, 3) measure the structure of jets to demonstrate how mergers create short GRBs, and 4) study the environment of the GW source. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2021-06-16T13:27:53.000 |
| 3199 | 2015.1.00428.S | 48 | Detecting FIR [OIII]emission from a galaxy candidate at z~10: a wedge into the pre-reionization era | We propose ALMA observations for a brightest (<26 AB) and most reliable galaxy candidate at z~10 in order to detect the far-infrared [OIII] 88.33 micron emission line redshifted into Band 7. These observations will spectroscopically confirm the redshift of the candidate, break the current spectroscopic redshift record, and put the first constraint on baryon physics of galaxy formation in the pre-reionization era. We will also detect the dust continuum from the galaxy with a high significance even in the case of non-detection of the line and constrain formation and evolution processes of these tiny solid particles in the earliest Universe. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2018-05-02T18:14:47.000 |
| 3200 | 2015.1.00261.S | 21 | Cyanoacetylene deuteration and the link with the Solar System early phases | Deuteration is a powerful diagnostic tool to understand the early phases of the Solar System formation. This proposal focuses on the deuteration of cyanoacetylene (HC3N), a major precursor of organic material in comets and meteorites. The goal is to obtain maps of the HC3N/DC3N abundance ratio in three sources that represent early phases of solar type star formation: L1544, L1527 and OMC-2 FIR4. They have been selected based on the detection of the DC3N in the framework of the IRAM-30m Large Program ASAI and on their capacity to represent different evolutionary phases. We propose to obtain maps of the HC3N and DC3N 10-9 lines, in order to accurately measure the DC3N/HC3N abundance ratio in the different components in the line of sight of the selected sources. | Astrochemistry | ISM and star formation | 2018-03-23T14:03:07.000 |
| 3201 | 2013.1.01177.S | 1 | A deeper look into Cha-MMS1 | We will study the stucture and kinematics of dense gas and search for molecular outflow around the central source of the Cha-MMS1 core. This low-luminosity source has been suggested to be a First Hydrostatic Core (FHSC). Our previous ammonia and 1.3 cm continuum mapping with the ATCA at a resolution of 7" reveals a compact rotating core and indications of an embedded outflow. With ALMA we aim to detect a disk-like structure around the central source and derive its mass and dynamical properties, like the angular momentum distribution. For this purpose we will use the N2H+(1-0) line plus 3-mm and 0.8 mm continuum. We will map the central part of the core in the CO(3-2) and 13CO(3-2). The presence of warm high-velocity gas should be evident in the CO lines, and they can be used to derive the mass, momentum rate, and the kinematic age of the eventual outflow. We will use the proposed observations to resolve the nature of the central source (FHSC or Class 0), and to estimate parameters characterising the internal dynamics of this very young star-forming core. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2016-07-07T07:44:34.000 |
| 3202 | 2016.A.00027.S | 18 | Constraining jet physics with multi-lambda variability studies of GRS 1915+105 | Two unanswered fundamental questions in accretion physics are (I) how does the accretion process onto compact objects result in powerful, relativistic jets, and (II) how powerful are these jets? In recent years, the study of the correlated multi-wavelength fast variability in black-hole X-ray binaries has led to a number of key results, providing jet speed estimates and tests of theoretical jet models. Here, we propose two 1-hour long ALMA observations of GRS 1915+105 in the Band 3, at 1 s resolution, to be taken simultaneously with approved observations in the near-IR (HAWK-I@VLT, 62.5 ms time resolution) and X-rays (XMM, < 1 ms) bands. We will study the accretion-jet connection on all available timescales, estimate the jet speed and determine the size of the jet emitting regions at both mm and IR wavelength, ultimately constraining the structure of the jet, studying how it evolves with flux/accretion rate, and test how well it fits standard models. We will achieve this by performing Fourier analysis of the jet mm emission over a wide range of timescales (1s--30min), and calculating the cross-correlation functions between mm and IR jet emission, and X-ray accretion flow emission. | Black holes | Stars and stellar evolution | 2018-04-30T19:09:28.000 |
| 3203 | 2015.1.01144.S | 27 | Determining the signature of star formation and AGN activity in the circumnuclear disk of NGC1068 | We propose to map the emission of the dense molecular tracers (HCN(1-0), HCO+(1-0), CS(2-1)) in Band 3, as well as CS (4-3) in Band 4, and CS (6-5) in Band 7, in NGC1068 at the resolution of 0.5". We have two immediate goals: (1) characterize the changes in the excitation and chemistry of the dense molecular gas on the critical scales (35-40pc) inside the circumnuclear disk (CND); (2) trace and characterize the shock component(s) within the CND and link their chemistry to the dynamics of the AGN-driven outflow. The case of this project builds on the results of our succesful Cycle 0 project, where we mapped at high resolution HCN(4-3), HCO+(4-3) and CS(7-6): these data have revealed the presence of 5 chemically distinct sub-regions within the CND. Analyses of the data (Viti et al. 2014) revealed a pronounced chemical differentiation across the CND and hinted at the presence of a three-phase ISM within each sub-region. We request a second, low J, transition of each species to determine the chemical and physical characteristics of each sub-region within the CND, and two more transitions of CS in order to relate the shock-driven chemistry to the molecular outflow driven by the AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-07-20T14:56:25.000 |
| 3204 | 2021.1.01385.S | 7 | How Hierarchical is Cluster Formation? A deep, high-resolution census of the G11.92-0.61 gas reservoir | A crucial open question is how (or even whether) the formation of a high-mass star is intrinsically linked to the formation of a surrounding cluster. Hierarchical cluster formation models differ on whether distributed subclusters contain high-mass protostars at early times or consist only of low-mass protostars (with high-mass stars forming only at late times and/or only in central hubs fed by filamentary accretion flows). We propose deep (5 sigma mass sensitivity 0.06 Msun, 10x deeper than the ALMA-IMF Large Program), high-resolution (0.2"~675 AU) ALMA 1.3 and 2 mm mosaics to obtain a census of star formation activity - including pre- and protostellar cores and the most massive protoplanetary disks - across the >2 pc^2 extent of a normal cluster-forming cloud (the gas reservoir for the deeply embedded massive protocluster G11.92). We will combine the 1.3 and 2 mm ALMA data with existing 0.2"-resolution 3 and 0.9 cm VLA images to measure and model the SEDs of cluster members, and gauge their accretion activity using multiple outflow tracers spanning a range in abundance and excitation. Using synthetic observations, we will make detailed comparisons with new AREPO simulations. | High-mass star formation | ISM and star formation | 2025-01-05T13:12:46.000 |
| 3205 | 2022.1.00906.S | 8 | Driving cold gas flows on the largest scales of AGN feedback | Cold gas accretion fuelling the supermassive black hole and AGN-driven outflows, directly regulating the cooling gas reaching the nucleus, are likely to be crucial elements of feedback in massive galaxies. ALMA observations of the molecular gas reservoirs in massive cluster centre galaxies have revealed billion solar mass gas flows that extend several to tens of kpc and are exclusively projected around radio bubbles inflated by a jet. The frequent superposition of filaments and ambiguity between inflowing and outflowing structures make it challenging to determine if molecular clouds are directly accelerated by the jet, or even if the jets are powerful enough to lift such substantial masses of cold gas. However, in the central galaxy of A1795, the 10^9 solar mass N filament is closely entrained around the N bubble over at least 10kpc and provides the best example of a clear outflow. Here we propose observations of CO(2-1), CO(4-3), 13CO(2-1), HCO+(5-4) and potentially C18O(2-1) to map the physical conditions in the gas flows and determine how cold gas flows are driven on the largest scales of AGN feedback. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2024-09-20T10:56:53.000 |
| 3206 | 2015.1.01188.S | 36 | Signpost of Effective Magnetic Field: Probing Drift Velocity | We propose H13CO+ (3-2) observations toward the two Class 0 protostars B335 and L1527 to probe drift velocities in their protostellar envelopes. We have been studying their gas motions from thousands of AU to inner 100 AU in neutral molecular lines, such as C18O. We find that the rotation in L1527 can be explained with the conventional model without incorporating magnetic field, while that in B335 can be better explained with our non-ideal MHD models with strong magnetic braking. Therefore, these two protostars represent the two extreme cases of weak and strong magnetic field. With the proposed observations, we will measure the rotational velocities of ions traced by H13CO+ on hundreds of AU scale, and compare with those of neutrals traced by our previous ALMA C18O observations. Our model calculations suggest that in L1527, there is no difference between ion and neutral velocities because of its weak magnetic field. In contrast, in B335, we expect the ion rotation is decelerated to subsonic and cannot be detected because of the strong magnetic braking. These two distinct features in drift velocity can be a signpost of dynamically ineffective and effective magnetic field. | Low-mass star formation | ISM and star formation | 2017-08-24T11:14:02.000 |
| 3207 | 2024.1.01227.S | 0 | CLASSY-CO: revealing the molecular gas fueling metal-poor star-forming high-z analogs in the local universe | Statistically-significant galaxy samples of the distant universe and reionization epoch have started to be revealed in the current JWST era. The knowledge on their molecular content is crucial to understand the star formation history of the universe. However, this is still unknown in the extremely metal-poor high-z environments. Here we propose to detect and map the molecular gas with the CO(2-1) in a selected subsample of metal-poor and low-mass local galaxies from the COS Legacy Archive Spectroscopic SurveY (CLASSY). CLASSY represents the first high-resolution spectral far-UV catalog of local star-forming galaxies, including high-z analogs, and also collecting multi-wavelength data, from the IR to the UV. CLASSY-CO will allow us to directly explore the connection between the molecular gas reservoir of these systems and the incident far-UV radiation as well as its connection with their interstellar medium properties. Our aim is to shed light on the role of CO as molecular gas diagnostic in high-z environments. Our study will allow to build an extremely powerful toolkit that will be pivotal for understanding the cold gas conditions of the earliest galaxies. | Dwarf/metal-poor galaxies | Local Universe | 2025-10-25T16:14:33.000 |
| 3208 | 2017.1.01409.S | 57 | Revealing the mechanism of massive star formation in NGC6822 | It is known that large star complexes are often formed in massive giant molecular clouds (GMCs). We found that the GMC in W51, one of the most luminous star forming regions in the Galaxy, consists of multiple velocity components and that these velocity components are colliding with each others to trigger massive star formation in W51. It is important to advance our knowledge on W51 to the similar GMCs in the extra galaxies to confirm that the formation mechanism is a common among the galaxies. In this proposal, we focus on the massive star-forming region Hubble V in the nearby dwarf irregular NGC6822, which shows a similar star formation properties as W51, proving an ideal site for our purpose. We propose to observe 12CO(2-1), 13CO(2-1), 13CO(3-2), and H30alpha emission lines as well as the continuum at a spatial resolution comparable with that in our study of W51, ~1 pc. We will apply our method used in the W51 GMC to reveal the internal structures of the GMC, which will allow us to make direct comparisons between W51 in the Galaxy and Hubble V in NGC6822, leading to a comprehensive understanding of massive star formation in GMCs. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2020-06-21T00:00:00.000 |
| 3209 | 2021.1.00934.S | 66 | The Assembly of the Earliest Massive Quasar Host Galaxies | The existence of billion solar mass BHs at z>~6.5 and the detection of strong gas and dust emission in their hosts indicate fast build-up of both the earliest supermassive black holes (SMBHs) and their massive host galaxies. Recent ALMA [CII] imaging of z~6.5 quasars suggests a diverse range of morphology and kinematics, indicating a complex growth history of these early massive systems. However, limited by the spatial resolution and the lack of detection of the hosts' stellar light, the assembly history of these massive galaxies are still poorly understood. We propose ALMA high resolution (~0.12" or ~600 pc) observations of a carefully selected representative sample of bright quasar host galaxies at z~6.5 -7. Together with the approved high resolution JWST observations for their stellar emission in rest-frame UV/optical, the ALMA observations will provide unparalleled constraints on the morphology, gas kinematics, dynamical mass, spatially resolved star formation surface density, and dust reddening of these massive hosts, which will finally enable us to understand the assembly of the first massive galaxies in a statistical manner from a multi-wavelength perspective. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2022-11-25T20:41:54.000 |
| 3210 | 2016.1.00622.S | 30 | Delineating the hot neutral interface in MonR2 | PDRs are ubiquitous environments where chemistry is driven by UV photons from nearby O & B stars. Reactive ions are thought to be excellent PDR tracers. In particular, high fractional abundances of CO+ are expected in the HI/H2 transition layer of dense PDRs. Recently, our team obtained, for the first time, a map of the CO+ ion in MonR2. We find that the CO+ emission is distributed in a chain of high density clumps forming a ring-like structure. These clumps present hints of fragmentation and photon-evaporation. However, higher spatial resolution and more sensitive observations are required to confirm this scenario. In this proposal we propose to image the CO+ reactive ion (together with different dense and ionized gas tracers) towards the most intense PDR clump around the HII region. The proposed high angular (0.6 arcsec) and spectral resolutions will allow us to perform a detailed study of the different layers within the clump and the kinematics of the requested lines. These results will be compared with other PDR tracers and chemical models, providing us with a whole picture of the chemistry in the HI/H2 layer in MonR2. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2018-05-29T21:43:37.000 |
| 3211 | 2015.1.00379.S | 166 | Gas content and gas depletion time of z>3 massive, star forming galaxies cont. | The evolution of the gas content and gas depletion time beyond redshifts of z=3 is basically unknown for massive (log(M_star/M_sun) > 10.0) normal star-forming, i.e. main sequence, galaxies. This redshift range (z>3) is important the cosmic star formation rate density increases. In Cycle 2 we detected 50% (44/86) of such photo-z selected galaxies in their 240GHz continuum - our proxy for cold gas mass. These z~3.2 objects show no change in gas content and gas depletion time once their location in the main sequence is taken into account. The trend of lower gas depletion times in higher redshift objects continues with a value of 0.4 Gyr at z~3.2. Thus we propose to double our Cycle 2 ALMA sample by observing 102 massive, normal star forming galaxies in the redshift range z=3-5 to (a) extend the redshift range probed, and (b) better sample the low and high stellar mass end. Our sample consists of VUDS galaxies in the COSMOS field with reliable spec-z (93 objects), supplemented by 9 ZFOURGE galaxies in the COSMOS field to better probe the high-mass end. These proposed observations will provide robust constraints vital for current galaxy evolution models. | Galaxy structure & evolution | Galaxy evolution | 2017-05-23T09:19:26.000 |
| 3212 | 2018.1.00310.S | 73 | Hunting for Structures in Protoplanetary Disks around Very Low Mass Stars | The detection and characterization of large mm-cavities of a fraction of protoplanetary disks (transition disks-TDs) has provided new insight into planet formation theories. The majority of the mm-cavities has been resolved around Herbig and T-Tauri stars, but recent discoveries have shown that cavities also exist around very low mass stars (<~0.1Msun, VLMs). One of these is CIDA1, a 0.1Msun object, where we detected a 20au cavity at 0.89mm. Cavities in VLMs disks are challenging all existing models, as the physical conditions in VLMs disks are not favorable to the formation of a cavity by massive planets or photoevaporation. Only 2 TDs have been detected around VLMs, but most of the existing observations lack the required sensitivity and resolution. We propose to survey the dust continuum emission of a sample of 5 VLMs in Taurus that, as CIDA1, have massive dusty disk relative to Mstar, using ALMA Band 7 at a resolution of 0.1". With these observations, we will estimate how common TDs are around VLMs and to test models of cavity formation. Characterizing a number of TDs among them will be critically important to our understanding of planet formation and disk evolution. | Disks around low-mass stars | Disks and planet formation | 2021-01-22T23:40:51.000 |
| 3213 | 2013.1.01058.S | 10 | Irradiated Shocks and Ionisation Sources in the Central Parsec of the Milky Way | We propose to study the origin and nature of the irradiated shocks in the interstellar environment surrounding SgrA*, the very centre of the Milky Way. We will use ALMA to resolve the spatial structures and kinematical patterns associated with the high-velocity CO line emission at the interface between the circum-nuclear disk and the inner central cavity. This component is beam diluted in our single-dish Herschel observations of the complete CO rotational ladder but can be inferred from the line profiles. Our observations using all 3 instruments on board Herschel have also revealed the presence of overabundant H2O and OH, as well as unexpected hot CO in the vicinity of SgrA*. We wish to understand the origin of this high velocity gas, and its heating and ionisation sources, using ALMA to search for the key missing information and to determine both the spatial structure and the ionization fraction using well established molecular tracers (HCO+, HOC+ and SO+). | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2016-09-23T00:00:00.000 |
| 3214 | 2011.0.00004.SV | 0 | Science verification observation of M100 | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2016-06-24T14:02:06.000 |
| 3215 | 2017.1.00518.S | 40 | C-C-Complexity in solar mass protostars; pushing the limit | The goal of this proposal is a deep Band 3 search for complex three-carbon molecules toward the solar-mass protostar IRAS16293-2422B, specifically the biologically interesting sugar alcohol glycerol. Production of this molecule has recently been demonstrated in the laboratory under the same cold interstellar conditions that lead to abundant glycolaldehyde which has been amply detected in IRAS16293. The same data set will also provide a deep search for the three-carbon alcohol propanol, and will more generally address the question of where the confusion limit lies in low-frequency data of line-rich sources. Together with available PILS results, these very deep observations will also allow a detailed comparison with the chemical inventory of comet 67 P/C-G and address the question whether the interstellar composition is preserved or not en route to the comet-forming zones of disks. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-08-02T18:47:18.000 |
| 3216 | 2013.1.00246.S | 2 | Highest Resolution Imaging of the Thermal Sunyaev-Zel'dovich Effect | We propose to perform the highest resolution imaging ever achieved of the thermal Sunyaev-Zel'dovich effect (SZE). Our target galaxy cluster, RX J1347.5-1145 at z = 0.45, is best-suited for the SZE imaging in Cycle 2, because of its compact size and the largest SZE signal known. It also hosts a violent merger as revealed by our past investigations. By achieving the 4 arcsec resolution in Band 3, we aim at i) identifying the shock front location and direction, ii) determining thermal and kinematic energies of the shock, and iii) unveiling heating mechanism of the intracluster medium. This will open new directions in exploitation of the physics of galaxy clusters and serve as a pathfinder for more comprehensive SZE studies to be done with full ALMA. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2016-04-10T14:56:35.000 |
| 3217 | 2021.1.01364.S | 23 | Spatiochemically Profiling the Inner Coma of C/2021 A1 (Leonard) | The pristine long-period comet C/2021 A1 (Leonard) is heading towards the Sun for the first time in 80 000 yr. It is predicted to be the brightest naked-eye comet since the historic long-period comet C/1995 O1 (Hale-Bopp). The upcoming December 2021 apparition of C/2021 A1 (Leonard) presents a very rare opportunity to comprehensively spatiochemically profile its inner coma with ALMA. We propose to inventory the chemical constituents - both simple and complex - in the inner 0.25'' (40-400 km) region at a sensitivity superior to all prior cometary observations carried out with ground-based facilities. We combine an unbiased spectral census across a 7.01 GHz bandwidth with a set of smaller spectral windows dedicated to specific molecular lines, covering a total bandwidth of 9.40 GHz. These data would be a unique glimpse at the pristine chemical ingredients from the assembly of our Solar System and, potentially, the origins of prebiotic compounds delivered to the early Earth. With ALMA, we have the possibility to set the new gold-standard for cometary observations for decades to come and investigate their implications for the physicochemical properties of the Solar Nebula. | Solar system - Comets | Solar system | 2023-02-23T15:15:27.000 |
| 3218 | 2021.1.01342.S | 163 | [CI] as a molecular gas tracer in star forming galaxies at high redshift | The CO(1-0) transition is the main tracer of the cold molecular gas in galaxies. However, it is severely limited at high redshift due to its intrinsic faintness and reduced contrast against a warmer CMB. The [CI](1-0) line has been proven to be a promising alternative molecular gas tracer, since it has a similar critical density to CO(1-0) and maintains a higher contrast against the CMB. However, no study has directly compared the ground-state [CI] and CO transitions in a high-z galaxy due to the low number of current CO(1-0) detections at z>2. This is set to change with incoming VLA observations targeting CO(1-0) in an unprecedented sample of 30 unlensed sources at z=2-5. We propose to target [CI] in 15 sources from this sample, which will allow us to 1)Constrain the CO(1-0)/[CI](1-0) correlation and investigate trends with e.g, dust mass; 2)Test CO, [CI] and dust-based molecular gas mass estimates; 3)Place the first observational constraints on the CMB suppression of CO(1-0) across redshift and 4)Derive the local ISM conditions in the targets. The proposed study will more than double the current number of unlensed z>2 submm galaxies with both CO(1-0) and [CI](1-0) detections. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-03-16T07:34:16.000 |
| 3219 | 2016.1.01400.S | 53 | The secret lives of BADGRS | We have discovered a very nearby population of extremely blue galaxies with Log M* = 7.5-9.5 Msun and high gas fractions (50-95%) that also have the highest specific dust masses of any local population. They have extended and clumpy starformation and H2/dust ratios over an order of magnitude lower than typical star forming spiral galaxies, depsite reasonably high metallicities (0.8Zsun). Their inferred molecular gas depletion times are ~250 Myr, overlapping with those in LIRGs and ULIRGs but at ×100 lower LIR. Instead, these sources represent a far more common phase of galaxy evolution; comprising more than half the galaxies discovered in the Herschel-ATLAS local volume sample. They are full of paradoxes - dusty but transparent, UV bright but with cold dust and high gas fraction but high enrichment. We will explore their dust properties, CO dark gas components, the effects of cosmic rays on CO, disk stability and conditions for H2 formation. Our ALMA observations will probe diffuse and dense gas tracers and dust emission on GMC scales (~70 pc) revealing the secrets of these gas rich and potentially unstable disks. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2017-12-30T03:24:10.000 |
| 3220 | 2011.0.00548.S | 0 | Resolving FU Ori v2 | The FU Ori phase is likely vital to the build up of the mass of stars. However, little is known about the mass distribution in the disks surrounding these objects. Particularly, FU Ori itself is undergoing rapid accretion due to gravitational instability. Our proposed obesrvations take advantage of the opportunity to measure the link between the inner disk instability and the outer disk feeding of this instability through short, resolved, multi-wavelength continuum observations. We also may potentially derive other disk properties through the detection of a variety of molecular species. These observations are vital to understanding this key process in star formation. | Disks around low-mass stars | Disks and planet formation | 2014-02-25T16:59:00.000 |
| 3221 | 2016.1.00121.S | 44 | Massive Molecular Filaments in a Nearby Disk Galaxy | Our goal is to discover, for the first time, massive molecular filaments in a nearby disk galaxy, NGC300, as traced by 13CO(2-1). Such structures, extending ~100pc in length, but often with ~parsec-scale widths, have only recently been identified in the Milky Way. Their kinematic coherence is a great challenge to theoretical models and simulations of the interstellar medium and its star formation activity. We aim to achieve our goal by imaging a 1kpc by 1kpc patch of the disk at high angular resolution (0.14", equivalent to 1.3pc), while also being sensitive to the largest 1kpc-scale structures, via ACA observations. In addition to 13CO(2-1), we will also image 12CO(2-1), C18O(2-1) and the 1.2mm continuum. The "bird's-eye" extragalactic view of the expected network of massive, dense molecular filaments will allow unambiguous and detailed comparisons to be made with numerical simulations of GMC formation and evolution. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2018-07-02T01:14:07.000 |
| 3222 | 2018.1.01780.S | 73 | Detailed observations of molecular cloud toward the peculiar supernova remnant W49B | We propose the detailed CO observations toward the supernova remnant (SNR) W49B. W49B has unique appearances, the "barrel-like" structure in the radio and infrared and the "jet-like" X-ray distribution possibly originated by a jet-driven supernova. Because the number of SNRs with jet-like feature is very limited, W49B is a special site for the study of environment of asymmetric jet-driven SN explosion. The molecular cloud associated with W49B has not been well determined yet. We conducted an analysis of 12CO(J=1-0, J=3-2) data of single-dish telescopes (the Nobeyama 45 m telescope and the JCMT). We found (i) the clouds corresponding to the radio and infrared filaments, (ii) the possibly shock interacting clump with a high intensity 12CO J=3-2/J=1-0 ratio, and (iii) the velocity distribution of the expanding cloud with 20 arcsec resolution. However, this resolution is not high enough to compare with the barrel and the jet-like X-ray. Using the ALMA CO(J=2-1) observations with the resolution of 5.7 arcsec (~0.2 pc), we will investigate (i) the more detailed molecular environment, (ii) the physical properties of the cloud, and (iii) the origin of the jet-like X-ray and SNR W49B. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-07-16T07:17:42.000 |
| 3223 | 2022.1.01595.S | 10 | Complex chemistry in shocked outflows around oxygen rich low-mass evolved stars | Low-mass stars are major contributors to the enrichment and growth of chemical complexity of the Universe. Substantial outflows of dust and gas are injected into the ISM during the late stages of low-mass stellar evolution. Some evolved objects, such as post-AGBs, experience fast shocks that disrupt their circumstellar envelopes activating a complex chemistry, resembling that of young stellar objects, that is poorly characterized. Recently, methanol and other organic precursors have been found in the circumstellar envelopes of two well-known evolved low-mass stars. We aim to investigate their molecular content in lines of shock-related species and organics precursors. This observational study will be complemented with gas-phase chemical models aiming to characterize their molecular emission, determine the physical conditions and the underlying chemical processes that lead to the formation of species such as methanol in shocked outflows. | Post-AGB stars, Evolved stars - Chemistry | Stars and stellar evolution | 2024-06-01T11:38:27.000 |
| 3224 | 2021.1.00740.S | 17 | Extragalactic Cloud Scale Observations of High Critical Density Tracers - Bridging the Gap to the Milky Way | Low-resolution mapping of high critical density tracers like (e.g., HCN, HCO+, HNC, CS) and wide-field, high-resolution CO mapping across nearby galaxies have each tremendously improved our understanding of the physics regulating star formation in galaxies. Here, we propose to take the next major step by combining both approaches: cloud-scale (high resolution) mapping of density-sensitive lines over a wide field in the nearby, massive, vigorously star-forming spiral galaxy NGC 2903. ALMA is uniquely suited due to the combination of sensitivity and resolution required for this innovative program. Our main goal is to relate gas density, star formation (via HST-PHANGS LP) and molecular cloud properties (via ALMA-PHANGS LP) across almost the entire galaxy disk (nuclear burst, gas-rich bar, spiral arms) for the first time at cloud scale and directly matched resolution. This program will put popular star formation theories to the test in diverse environments, link directly to studies of local Milky Way clouds and test how well common extragalactic "dense gas tracers" tell a self-consistent story. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2025-03-30T08:30:46.000 |
| 3225 | 2023.1.00931.S | 0 | Blowing in the wind: An ALMA multiband study of dust in two protostellar winds | The aim of this proposal is to study the interface between protostellar disks and jets, and test the hypothesis that dust can be carried away at this interface via a wind. We have undertaken an extensive search of the ALMA Science Archive, and we found promising evidence for dust continuum extensions in a handful of sources, that we now wish to expand with consistent observations in terms of angular resolution (corresponding to 20 au) and multi-band coverage. Beyond the question of "is dust being launched into protostellar winds?" we seek to address how much dust can be launched into a wind, as compared to the mass of the disk; how far from the disk this dust can be observed; and the dust grain size distribution in the wind launching region. Not only do we aim to constrain if winds can remove dust grains from a disk, but quantify at what level winds affect early disk formation and evolution. The scenario probed here has important impacts on the mass, composition, and evolution of the disk, which is ultimately the reservoir for planet formation. ALMA is the only facility with sufficient angular resolution and multi-band coverage for this study of sub-mm-size dust grains. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2025-09-24T10:59:04.000 |
| 3226 | 2016.2.00097.S | 187 | Cold Molecular Gas in Massive Clusters of Galaxies at z>0.3 | The cores of clusters of galaxies with the most rapidly cooling intracluster medium on scales of <100kpc all have a massive galaxy at the focus of this intense X-ray emission that shows strong star-formation, extended optical line emission, enhanced AGN activity and cold molecular gas. We propose Morita Array observations of 11 of the most striking examples of these systems at z>0.3 that currently lack any constraints on their CO emission (where currently we have just 3 detections). Any significant subset of these targets would allow us constrain the evolution of these most extreme cluster cores compared to the 12-20 comparable systems known at z<0.3. These observations are ideal fillers and require just a single visit to complete. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2018-08-12T22:23:23.000 |
| 3227 | 2023.1.00220.S | 0 | Exploring a Phoenix-like galaxy cluster with the Sunyaev-Zel'dovich effect | We propose to observe the Sunyaev-Zel'dovich effect (SZE) from PKS1229-021 with ALMA Band 3. PKS1229-021, the target of this proposal, is known to be a high-z, X-ray luminous galaxy cluster underlying an X-ray luminous quasar in its brightest cluster galaxy (BCG). PKS1229-021 was originally recognized as a textbook example of an FR-II radio source at z=1.043 launching strong jets. Recently, a detailed Chandra X-ray analysis detected diffuse, hot X-ray emitting gas (intracluster medium; ICM) from the host galaxy cluster, and found the possible presence of a prominent cool core at the cluster center. However, the quasar is too bright in X-rays, causing heavily piled-up events in Chandra observations. Thus, it is impossible to measure the thermodynamic properties of the ICM at the center using X-ray observations. Our SZE observation is complementary to Chandra X-ray observations and will provide a unique opportunity to detect a prominent cool core and measure the ICM properties at the center. Therefore, we propose ALMA SZE observations for PKS1229-021. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2025-11-17T14:31:18.000 |
| 3228 | 2023.1.01350.S | 0 | Observation of the southern hemisphere stratospheric winds of Saturn | In Saturn, Eastward zonal winds have been measured by tracking cloud motions up to the tropopause level. In the cloudless stratosphere, 200 km above cloud level, the winds have been directly measured for the first time by Benmahi et al. (2022) with ALMA. However, observation geometry limited the measurements to the northern hemisphere and the southern hemisphere stratospheric winds remain unconstrained. With this project, wwe aim at measuring the southern hemisphere winds in the stratosphere of Saturn to compare them with those in the northern hemisphere. Our observations will also allow us to constrain the temporal variability in the equatorial region, where winds are expected to oscillate with a period of about 15 years, by comparing our measurements to those made in 2018 and reported in Benmahi et al. (2022). Finally, the favorable geometry and enhanced spatial resolution will enable us to disentangle a zonal vs. aurorally-driven origin of the polar winds, tentatively detected by Benmahi et al. (2022). | Solar system - Comets | Solar system | 3000-01-01T00:00:00.000 |
| 3229 | 2023.1.00725.S | 0 | Establishing how quasars impact on the molecular gas in their host galaxies | The role of quasars in galaxy evolution remains controversial. Recent work has compared ~kpc-scale quasar-driven molecular outflows to the driving of ~10kpc molecular gas filaments by radio lobes from brightest cluster galaxies. This works suggests that the latter `radio feedback' is the more effective at impacting upon molecular gas. However, we lack a systematic search for different feedback processes in the quasar samples. Indeed, recent radio + CO analyses of nine z<0.2 type 2 quasars, already highlights that `radio feedback' on molecular gas can also be relevant in this population. However, this sample was pre-selected for known extreme gas kinematics. Therefore, we propose to observe the other eight targets from the parent sample to remove this bias. We will systematically search for molecular outflows and radio-gas interactions, measuring properties such as velocities, outflow rates and driving efficiencies. We will provide a quantitative assessment of the relative importance and efficiency of different AGN feedback mechanisms on the cold molecular gas on a homogeneous and representative sample of quasars. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-08-14T08:33:18.000 |
| 3230 | 2022.1.01003.S | 187 | Following the energy trail with CH+ in strongly lensed starburst galaxies before cosmic noon | Whatever its origin - stellar or AGN feedback, gravity - turbulence acts as a long-lived mass energy buffer and is a critical process regulating the growth of galaxies in the early universe. Large turbulent reservoirs of diffuse molecular gas have been detected with CH+(1-0) absorption lines against the dust continuum emission of strongly lensed sub-mm galaxies (SMG) at z~2.5. They extend to up to 40 kpc from the SMGs. Extremely broad CH+(1-0) emission lines trace shocks at the interface of galactic winds and the circum-galactic medium (CGM). Thanks to the unique properties of CH+, the major energy releases can be quantified and a steady-state regime of star formation is found in these SMGs in which a gas mass inflow rate comparable to the star formation rate is required to sustain the mass and turbulent luminosity of the CGM over the duration of the starburst phase. Here, we extend the search for CH+(1-0) lines in 18 strongly lensed SMGs, at earlier epochs, 4 | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-04-18T10:24:45.000 |
| 3231 | 2017.1.00230.S | 85 | Dense Gas Tracers, Star Formation, Cloud Properties, and Galaxy Structure in Five Nearby Spiral Galaxies | We propose to use ALMA to measure the emission from high critical density transitions in Band 3 (``dense gas tracers) from the inner 3-5 kpc of five nearby star forming galaxies. With these observations, we will double the sample of galaxies where we measure the environmental dependence of the dense gas fraction (traced by HCN/CO or HCO+/CO) and the apparent ability of dense gas to form stars (e.g., SFR/HCN) on environment. So far, a strong environmental dependence of is observed, but with large galaxy-to-galaxy variation and limited statistical significance. This proposal will at last give us 6-12 independent measurements per 0.1 dex bin in stellar surface density, ISM pressure, and gas depletion time. Only ALMA can simultaneously resolve the inner part of the galaxies into discrete environments and achieve the sensitivity needed to detect these lines. We choose our targets to overlap existing high resolution CO imaging and a wide-field single dish survey. This will allow us to test how density-sensitive line ratios (e.g., HCN/CO) depend on the local properties of molecular clouds and so connect the density distribution from the galaxy to cloud to microscopic scales. | Merging and interacting galaxies | Galaxy evolution | 2020-03-15T00:00:00.000 |
| 3232 | 2019.1.00102.S | 116 | A survey for the molecular gas content in normal star-forming galaxies at z~1.5: a VLT/KMOS and ALMA synergy | We propose a dual band ALMA survey in CO(2-1)/band-3 and CO(5-4)/band-6 towards 18 star forming galaxies at z~1.5 selected from the KMOS Galaxy Evolution Survey (KGES). Targets are carefully selected from a parent sample of ~500 galaxies presenting spatially resolved and good quality H-alpha dynamics. This survey will give a major step forward on the number of Halpha-selected galaxies with near-IR IFU data and CO detections at high-z. Our science goals are to: (1) get star-formation efficiencies in terms of the kinematic state of galaxies, (2) measure the gas to dust ratio to confirm the validity of the submm continuum as a tracer of the molecular gas content in "normal" high-z galaxies, (3) probe the cold vs warm molecular gas content to constrain the heating mechanism in these galaxies, (4) put further constraints on the MH2-L'co conversion factor by using metallicity ([NII]/Halpha) and dynamical arguments, (5) confront the amount of molecular gas content to semi-analytical cosmological prescriptions at z~1.5, and (6) in case of bright line detections, explore the ionised vs. molecular gas kinematics to infer the degree of stability in galaxy disks. | Spiral galaxies, Surveys of galaxies | Local Universe | 2021-03-30T20:53:10.000 |
| 3233 | 2016.1.00358.S | 43 | Protolunar disks around directly imaged young exoplanets | The gas giant planets of the Solar System are surrounded by moons in large quantities, with at least 50 prograde moons thought to have formed in situ. Just like the Sun is not the only star surrounded by planets, it is very likely that extrasolar gas giant planets are also surrounded by lunar systems. Building on the properties of the solar system regular satellites, we derive models for minimum-mass protolunar disks. Using 3D radiative transfer, we show that such late circumplanetary debris disks would be readily observable given the incident flux from the central host star, and are even brighter when heated from the still-warm giant companion they are surrounding. We propose to test our predictions by observing three confirmed companions around nearby (50 pc) young (<30 Myr) stars with ALMA in Band 6 continuum and 12CO J=2-1 at 0.1 resolution. We are resubmitting our ongoing Cycle 3 program for PZ Tel and AB Pic (cat. B), and adding 51 Eri. Given our simulations, protolunar disks around these companions should be detectable at 10 sigma with just a few minutes (7-17 min) on source. Our science requires only 1 hr per target including calibrations. | Debris disks, Exo-planets | Disks and planet formation | 2018-10-19T04:23:23.000 |
| 3234 | 2018.1.00951.S | 10 | Solving the Puzzle of Molecular Masses in Massive Starbursts | Gas masses are extraordinarily important to constrain histories of mass accretion and the buildup of galaxies. Most mass determinations, at low and high redshift, rely on some combination of CO and/or dust emission, often calibrated on local galaxies. In warm starbursts there is the possibility of using the ground transition of deuterated hydrogen to obtain an independent molecular mass determination. Because it is a weak far-infrared line, such measurements and their potential have not been well explored in nearby galaxies. But ALMA can perform these measurements in a handful of massive systems at high redshift, leap-froging ahead and obtaining an independent determination of their gas content. In this project we request time to attempt the detection in a very well characterized, extremely bright source, that should provide the best benchmark to understand the applicability of this technique. | Starburst galaxies | Active galaxies | 2021-03-27T19:41:35.000 |
| 3235 | 2015.1.01147.S | 30 | CO Imaging of Ultraluminous Infrared QSO Hosts | CO survey of the host galaxies of ultraluminous infrared QSOs (IR QSOs) reveals a massive reservoir of molecular gas and confirms that the FIR emission of IR QSOs are mainly from star formation (SF). We propose to map 8 IR QSOs at z=0.061-0.190 showing the strongest CO emission to study the distribution and kinematics of molecular gas on sub-kpc scale with the ALMA. This will be the first attempt to systematically probe the ~1 kpc nuclear regions of IR QSOs where SF/AGN activities play important roles in shaping up the galaxy evolution (once combining with few nearest IR QSOs that have been imaged in CO, e.g., MrK 231). With the accurate measurements of CO size and kinematics, we can study the M_BH-M_bulge relation and the kinematic signature of molecular gas around black holes in the IR QSO phase. The high resolution ALMA observations will also enable us to resolve the size and geometry of molecular outflows in the hosts of IR QSOs. Together with the multi-wavelength studies of local ULIRGs and PG QSOs, the systematic studies of IR QSOs will help us better understand the co-evolution of starbursts and AGNs as well as provide the best examined local analogues to those at high-z. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-03-06T09:39:04.000 |
| 3236 | 2023.1.01728.S | 0 | Characterizing the Orbital Motion of Close Protostellar Multiples | We propose high-angular resolution follow-up of known close (<400 au separation) multiple protostar systems in the Perseus and Orion star forming regions to begin characterizing their orbital motions. These systems have been discovered as multiples primarily through unbiased ALMA and VLA surveys of known protostars within the aforementioned regions. With the surveys having been conducted ~8-10 years ago, the detection of orbital motion within these close multiple systems is now possible. The orbital motion will ultimately enable the stellar masses and mass ratios to be characterized, in addition to orbital parameters like inclination and eccentricity. Some systems will have sufficent data to constrain orbital parameters with the proposed data, while others will require future observations. Many of these systems are hierarchical multiples and these observations will help establish if they have common proper motions, indicative of their physical association. Some close multiple systems are too faint to be detected by the VLA, thus, ALMA Band 7 is also proposed for the 14 systems that are most practically observed at shorter wavelengths where their dust emission is brighter. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2025-08-10T06:30:09.000 |
| 3237 | 2015.1.00310.S | 20 | Searching for Accretion Luminosity Variability in Deeply Embedded Protostars | Low-mass stars form via gravitational collapse of molecular cloud cores. The evolution of the mass accretion onto a forming protostar depends on the rate at which the interior of the core collapses, the significance of a circumstellar disk as a temporary mass reservoir and transportation mechanism, and the physics of how the inner disk accretes. Despite a clear requirement for time dependency in the accretion rate onto deeply embedded protostars and a large number of theoretical mechanisms for powering variability, our understanding of both the timescale and amplitude of variability is almost entirely unconstrained. We propose to use ALMA to observe twelve deeply embedded protostars in Serpens in continuum at 230 GHz in order to (a) compare against 2010 epoch CARMA observations to uncover rare large-amplitude accretion variation and (b) provide well-calibrated first-epoch brightness measurements for future comparison as part of a continuing campaign dedicated to uncovering the observational signature of episodic accretion. These observations are vital for discriminating between the various theoretical models of episodic accretion onto deeply embedded protostars. | Low-mass star formation | ISM and star formation | 2017-09-02T23:40:37.000 |
| 3238 | 2016.1.00543.S | 4 | Molecular Gas Mapping of the Node within the Cosmic Web at z = 3 | Models of cosmological structure formation in a cold dark matter universe request that the matter in the intergalactic medium (IGM) and the galaxies formed from it shape a cosmic web of walls and filaments. Recently we have found a promising candidate of such ongoing galaxy assembly along the IGM filament at the core of the z=3.1 SSA22 proto-cluster. Combining our 2'x3' ALMA deep imaging with deep Lyman-alpha and X-ray imaging, we have found that at least 12 submillimeter galaxies (SMGs) and/or X-ray Active Galactic Nuclei (AGNs) at z=3.09 are embedded in the filaments designated by the diffuse and extend Lyman-alpha emission. Here we propose a blind line scan using Band3 to uncover molecular gas reservoir at the core of the proto-cluster. Utilizing this 'molecular ALMA deep field', we will (i) measure CO luminosity functiona and the cosmic molecular gas mass density in the node of cosmic structure, (ii) unveil the link between molecular gas reservoir and cold intergalactic gas, (iii) uncover the environmental dependence on gaseous properties for various galaxy populations, and (iv) reveal how galaxies and super massive black holes (SMBHs) co-evolve in the proto-cluster core. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-08-16T08:42:36.000 |
| 3239 | 2023.A.00023.S | 16 | Simultaneous ALMA and JWST Monitoring of Sgr A* on March 21, 2024 | Variable emission provides a tool for probing the structure and physics of the accretion flow in SgrA*, with significant impact on our understanding of massive black holes in the nuclei of other galaxies. To address this issue, we propose to observe SgrA* for 8h at submm simultaneously with an already scheduled 8h JWST observation using NIRCam (2.1 & 4.8 microns) starting on 05:49:13 UT on March 21, 2024. The unique opportunity of observing SgrA* with NIRCam at two simultaneous wavelengths and ALMA at submm addresses the connection between SgrA*'s IR and submm flare emission by using synchrotron and adiabatic models of the variable emission. In addition, with its remarkable sensitivity and low background noise, the proposed measurements probe the hypothesis that the same population of particles are responsible for producing NIR and submm emission. Modeling the submm and NIR variability is critical to EHT's goal of improving future imaging of SgrA*. Lastly, submm IQUV polarization measurements combined with NIR flaring provide a fantastic opportunity to determine the evolution of the magnetic field on event horizon scale sizes in the context of expanding hot spots orbiting SgrA*. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2024-10-09T17:36:07.000 |
| 3240 | 2023.1.01346.S | 71 | High-mass Photoionising Protostellar Object (HiPPO) survey | Characterizing accretion onto very luminous compact objects is an universal astrophysical problem. How robust is disk accretion against the tremendous radiative feedback? How/why/when does accretion effectively end? To tackle these questions, we propose to study the accretion vs. feedback problem in the high-mass star formation laboratory. The proposed survey (HiPPOS) aims to determine the state of accretion of the massive young stellar objects (MYSO) powering young and early HII regions. These MYSOs are at an inflection point during their formation: does the rise of the radiative and ionizing feedback stop accretion? Or do MYSOs keep accreting long afterwards? HiPPOS will address these questions by studying, at 150 au resolution, a uniformly selected sample of 18 nearby (<3 kpc) young HII regions. By using ionized gas (free-free and recombination lines) and molecular tracers such as refractory and hot-core species we will determine the presence of disks and search for inflow and outflow motions within the HII regions, revealing the accretion status of the powering MYSO: either on-going or essentially finished. | High-mass star formation | ISM and star formation | 2025-01-08T12:47:01.000 |
| 3241 | 2013.1.00053.S | 0 | A search for the elusive sub-mm polarisation in protostellar disks | We propose to use ALMA in its narrow-field polarimetry mode to detect sub-mm polarized emission for the first time in a protoplanetary disk. ALMA's high resolution will avoid smearing out of the polarized signal, giving a 5x improvement in beam size and a factor of 100 improvement on the polarised flux over previous studies. The well-studied nearby disk HD163296 is ideal for this work, and we will image the polarisation out to a radius of 145AU to 0.3% rms, giving 60 vectors over the map and 12-15 vectors at the ALMA polarisation sensitivity limit of 0.1% (out to 100AU radius). The orientation and structure of polarisation vectors will allow us to pinpoint the grain alignment mechanism and the degree of alignment and grain non-sphericity. Even a non-detection will provide stringent limit on the shape of mm-sized grains, turbulent mechanisms hampering grain alignment and upper limits to alignment mechanisms. | Disks around high-mass stars | Disks and planet formation | 2017-02-05T11:57:04.000 |
| 3242 | 2021.1.00424.S | 248 | From cores to Brown Dwarfs: Unraveling the substellar formation mechanism in Lupus 4 | The primary mechanism of formation of brown dwarfs (BDs) is still under debate. Systematic studies in nearby molecular clouds are needed to shed light on how these objects form and so far only a few pre- and proto-BDs candidates have been reported in the literature. Lupus 4 is an excellent laboratory to study the formation of substellar objects. We have identified a set of pre- and proto-substellar candidates using 1.1 mm ASTE/AzTEC maps and analyzing its SED using optical to submillimeter database. We propose ALMA continuum observations at 1.3 mm using 0.6"-1.0" spatial resolution towards those promising pre- and proto-brown dwarfs candidates found in Lupus 4. Our main aim is to characterize the dust/envelope/disk surrounding these sub-stellar objects and to compare their properties with the ones from low-mass protostars and with theoretical models that predict the formation of BDs. As a secondary goal we will study the gas emission surrounding these objects. This proposal, requesting 8.15 hours, will enlarge the census of very young BDs an will privide important insights on their formation | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-05-13T01:33:23.000 |
| 3243 | 2016.1.00630.S | 19 | ALMA Observations of HBC 494: Gravitational Instability Clump or Interacting Disks? | FUor objects are pre-main sequence stars that are undergoing a period of intense mass accretion from their circumstellar disks. During these outbursts, their luminosity can increase up to 100 times L_Sun for Solar-type stars and their accretion rates can reach as high as 10^-4 M_Sun/yr. While the mechanism producing these outbursts is still unclear, several leading theories have been proposed: 1) Tidal interaction of a massive disk with an eccentric stellar or giant planet companion, 2) Magnetorotational instability activated by gravitational instabilities and 3) Disk Fragmentation developing spiral structures. ALMA Cycle-2 observations of the FUor object HBC 494 show an elongated structure in the continuum, which can be caused either by a gravitational clump or by an interacting disk. So far, no evidence of binary has been claimed for this object. A gravitational clump has been identified around the star beta Pictoris, which host a debris disk, but it has not been identified in a protoplanetary system so far. We aim to resolve this FUor object to disentangle which of three scenarios above may cause its outbursts. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2019-01-31T13:59:48.000 |
| 3244 | 2022.1.00433.S | 0 | Where does [CII]158um originate? A panchromatic ~20-pc scale view of ISM in a sub-L* galaxy at z=6 by ALMA and JWST | We propose deep high-resolution (~0.05") follow-up for [CII]158um line targeting remarkably bright multiple images of a strongly lensed galaxy at z=6 discovered by a 100-hr ALMA Lensing Cluster Survey. Among normal star-forming galaxies at z>6, both images are the brightest lensed sources known, (H~23.7mag, [CII] flux~20mJy), but intrinsically a faint z=6 sub-L* galaxy (Mstar~10^9Msun) due to high magnifications of mu~20&160. The current HST map (PSF~0.2") already hints the existence of small star-forming clumps. Combined with similarly high-resolution (~0."05-0."1) deep JWST/NIRCam and NIRSpec IFU observations scheduled in GO cycle1, we will assess the cold ISM distribution down to ~20-pc scales (source plane) via the major coolant line with underlying dust continuum, dramatically transforming our understanding of the inner structure of a typical z=6 galaxy by 1) identifying futher tiny [CII]-emitting clumps down to SFR ~ 0.002-0.01 Msun/yr, 2) studying detailed [CII] kinematics including the clump motions (inflow/outflowing), and 3) unveiling from where [CII] line & dust continuum arise. A comparable study is impossible, except for this uniquely lensed system at EoR. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-04-04T16:47:37.000 |
| 3245 | 2013.1.00221.S | 19 | Investigating strongly-shocked and X-ray-irradiated dense gas properties: SiO multi-transition 40pc-resolution imaging in the center of NGC1068 | The central 300pc circum-nuclear disk (CND) of Seyfert 2 galaxy NGC1068 seems to contain X-ray dominated regions (XDRs) and compact shocked regions. However the contribution of these mechanisms onto the existing molecular gas properties has not yet been clarified. In this program, we propose to observe the CND of NGC1068 by multiple SiO lines including J=2-1, 3-2, 5-4, and 6-5, which can trace both shocks and XDRs. We will derive the spatial distribution of SiO abundance (via rotation diagram) and kinetic temperature (via LVG analysis) from multi-transition lines. We aim to achieve the following science goals: (1) constraint of the spatial distribution of XDR: We will compare the obtained SiO abundance map with the existing X-ray flux image. The region where they correlate well is considered to be affected by the XDR. (2) detailed properties of the bulk of shocked molecular gas at the vicinity of the nucleus: Multiple SiO emissions can trace the bulk of the shocked gas. We will study the spatially resolved physical and chemical properties of shocked gas via temperature, abundance and line shapes. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-11-27T19:33:54.000 |
| 3246 | 2018.1.01106.S | 5 | After The Fall: An Ultra High-Resolution View of the Molecular Gas in a Post-Starburst Galaxy | Post-starburst galaxies (PSBs) are an important stage in the buildup of the present-day quiescent galaxy population. Likely relics of vigorously starbursting, major gas-rich mergers, PSBs had their star formation quenched within the last ~0.1-1 Gyr. We previously discovered extremely compact, turbulent molecular reservoirs in a sample of PSBs, all exhibiting extreme star formation suppression. This observing plan targets a single, gas-rich post-starburst, aiming to resolve its CO(2-1) and 1.3mm continuum emission on ~20 pc scales. Our Cycle 6 target, unresolved at 200 pc scales, possesses a gas surface density (at least) equivalent to Arp 220, but with a 10x lower star forming efficiency --- one of the most extreme objects of its kind. ALMA provides a unique opportunity: in its extended configuration, it delivers exquisite (0.02") spatial resolution, providing the ~20 pc physical resolution needed to fully resolve the incredibly dense molecular gas in this PSB. This is perhaps our best option to discern the mechanism which is suppressing star formation in PSBs, a result which will significantly advance our understanding of how starbursting galaxies die and fade into quiescence. | Starbursts, star formation, Galactic centres/nuclei | Active galaxies | 2021-01-31T18:18:44.000 |
| 3247 | 2016.1.00309.S | 36 | Direct detection of a quasar hyperwind through the Sunyaev-Zeldovich Effect | Feedback by AGN and extreme starbursts on the ISM of a host galaxy, and the surrounding intra-cluster/intra-group medium is very poorly constrained observationally, despite being a key ingredient in models of massive galaxy formation. Some of the best constraints on quasar winds could come from the Sunyaev-Zeldovich (SZ) effect, which measures the line of sight integral of the pressure through the wind. The energy in the wind can be directly related to the SZ signal. However, observations to detect the SZ signal directly are extremely challenging. Statistical studies using low resolution data from Planck, the Atacama Cosmology Telescope and South Pole Telescope have found marginally significant signals, however these are difficult to separate from the expected SZ effect from galaxy clusters around the quasars and emission from star formation in the hosts at high frequencies. Only a direct detection at a resolution of a few arcseconds can confirm feedback from a wind, and only ALMA can realistically attempt such a direct detection. Here, we propose to observe the most luminous quasar visible to ALMA in an attempt to obtain the first direct detection of hot gas in a quasar wind. | High-z Active Galactic Nuclei (AGN), Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE) | Active galaxies | 2018-04-22T01:02:21.000 |
| 3248 | 2019.1.00253.S | 30 | Shut It Down: Probing Molecular Feedback in z=4-5 Dusty, Star-forming Galaxies | One of the most important realizations of the last fiteen years is the vital role that feedback must play in the evolution of galaxies, particularly at the massive end (Mstar > 10^11Msun). Star formation appears to have been efficiently "quenched," but the processes by which quenching occurs are poorly understood. Theoretical models invoke feedback from AGN and/or star formation to disrupt, expel, or heat the gas and prevent further star formation. Recent observations and circumstantial evidence suggests that the bulk of star formation in the earliest quiescent galaxies took place in dusty, star-forming galaxies (DSFGs) at z>4. We propose to test models of feedback and the evolutionary connection between DSFGs and quiescent galaxies by spatially and spectrally resolving massive molecular outflows in 6 z=4.2-5.3 galaxies. Our observations will constrain the outflow geometry and mass loss rates, allowing us to determine whether quenching is due to gas depletion or gas removal. Our targets span a factor of 12 in star formation rate (SFR) and 30 in SFR surface density, giving a large dynamic range to constrain outflow scaling relations and match local work at high-z. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2021-02-15T04:27:15.000 |
| 3249 | 2023.1.00727.S | 0 | Studying the thermal properties of a z=1.3 radio-halo galaxy cluster | We request deep ALMA Band 1 observations to obtain a high-resolution view of the Sunyaev-Zeldovich (SZ) effect in the direction of the high-redshift galaxy cluster ACT-CL J0003.9+1642 (z=1.305). Radio observations provide evidence that the system hosts Mpc-scale radio emission associated to a radio halo. This would indicate a fast and efficient growth of cluster magnetic fields, ~2 Gyr earlier than the most distant cluster known to host a radio halo (El Gordo; z=0.87). Understanding what mechanisms have induced such a strong amplification of the ICM magnetic field --- challenging our current understanding of evolution of intracluster magnetic fields --- require a detailed characterization of the dynamical and physical state of the underlying intracluster medium (ICM). For such reason, we plan to perform a detailed modelling of the pressure distribution down to scales of tens of kpc. This will be used for studying small-scale structures associated to the dynamical state of ACT0003, and jointly with complementary radio data to perform a comparative study of the thermal and non-thermal properties of the ICM. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2025-11-19T13:07:50.000 |
| 3250 | 2016.1.00672.S | 1468 | Completing the SPT+ALMA Redshift Survey | In Cycles 0, 1, and 3 we performed a spectroscopic redshift survey of high-redshift strongly-lensed sources selected from the South Pole Telescope (SPT) Survey. These programs have yielded 57 secure redshifts from carbon monoxide (CO) with a median redshift of z~3.9 and extending out to z=6.9. The clean selection of these sources, systematic followup, and spectroscopic completeness of this sample is important for constraining models of galaxy evolution, studying the evolution of the interstellar medium across cosmic time, and constraining the nature of dark matter via strong gravitational lensing. The SPT+ALMA Redshift Survey has provided high-impact science results and laid important groundwork for the coming decade. Here we request 27.8 hours to obtain Band 3 spectral scans for all remaining 21 sources from the 2500 square degree SPT Survey. This will complete the 81 sources that comprise the SPT sample. Completing this survey will have enormous legacy value for ALMA and the community. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-03-31T22:29:18.000 |
| 3251 | 2022.1.00665.S | 444 | Toward a complete census of methanol budget in isolated protostars | Organic molecules have been found toward embedded protostars, especially at the vicinity of protostars where the temperature increases. Methanol, the most simple complex organic molecule, is the key molecule on the path toward a complex chemistry. While a combination of gas-grain chemistry and thermal desorption suggests the appearance of warm methanol around protostars, non-thermal desorption as well as gas phase chemistry may be more active than expected at the low temperature extended envelope. JWST and ALMA presents a unique synergy to probe the molecular budget in ice and gas phase at high sensitivity, providing a complete view of chemical evolution in protostellar cores. To completely measure the methanol budget from the low temperature envelope to the high temperature disk-forming region, we propose to survey methanol transitions with upper-state energies ranging from 20 to 500 K toward four isolated protostars whose ice compositions will be observed by JWST. Therefore, we will not only constrain the chemistry of methanol at low temperature but also present a complete methanol budget of ice and gas complemented by JWST. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-12-26T20:12:14.000 |
| 3252 | 2019.1.01091.S | 12 | Revealing planet migration via dust substructures in isolated outer disks | Planets are thought to migrate as they grow and evolve in their parent protoplanetary disk, due to the balance of gravitational and pressure torques. Migration is commonly invoked to explain the existence of hot Jupiters and the concentration of low-mass exoplanets at small orbital radii. In general, several processes can influence the rate of planet migration, and result in both inward or outward drifts. But there is little observational evidence of migration beyond the empirical motivation found in the Solar System. Using ALMA, we found signatures of planet migration via dust structures in the outer region of a gapped disk. HD169142 has a system of three fine rings with asymmetric mutual separations. A single low mass planet can account for the triple ring structure, while its inward migration naturally explains the rings' mutual separations. Here, we aim to explore whether the observation in HD169142 is a rare anecdote, or if it reflects a universal phenomenon in gapped disks outer regions. We will test for low-mass planet signatures in HD97048, whose outer region shows hints of a tripple-ring that can be used to inform on the radial migration of the embedded perturber. | Disks around low-mass stars | Disks and planet formation | 2023-02-14T00:00:00.000 |
| 3253 | 2023.1.01471.S | 0 | An ACA Survey of Molecular Gas in Mergers and Dual AGN | Major galaxy mergers are thought to play an important role in fueling supermassive black hole (SMBH) growth. However, observational support for this hypothesis is mixed, with some studies showing a clear link between merging galaxies and luminous quasars and others showing no such association. Galaxy merger simulations and observations suggest dual AGN activity (Koss+12) and obscuration peak when the two galactic nuclei are close to each other. We propose a survey of all 34 nearby (z<0.05) hard X-ray selected AGN from Swift BAT in mergers (4-28 kpc) that can be resolved within a single 7m ACA observation at 230 Ghz (10-25'' separation) and 100 Ghz (>25'') to 1): study the role of molecular gas in AGN activation in mergers and 2) use continuum observations to search for highly obscured primary AGN and undiscovered obscured secondary AGN. These observations will perform the first large ACA study of AGN in mergers, quadrupling the number of dual AGN studied at wider separations (>5 kpc) and providing a critical comparison sample of single AGN in mergers. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2025-03-19T20:56:48.000 |
| 3254 | 2016.1.01493.S | 26 | ALMA Observation of a New SiO Maser Source Associated with High-mass Star Formation | Unlike H2O, CH3OH, and OH masers, SiO masers are rarely detected in star-forming regions. There are only 7 confirmed SiO maser sources associated with star formation. We recently detected SiO maser emission at 86GHz toward NGC6334F (d=1.21 kpc), which is a well-known high-mass star-forming region showing H2O maser flaring since 2015 February. We propose to observe NGC6334 in the 86~GHz SiO maser line at 0.4 arcsecond spatial resolution. It is also possible to observe multiple other molecular lines that trace dense cores (H13CO+) and outflows (SiO v=0, HCO+, HCN, CS). The primary goals of this proposal are to pinpoint the positions of the SiO masers and to figure out what objects the masers are physically associated with. We plan to examine the relationship between the SiO masers and the flaring H2O masers. We will be also able to investigate the detailed physical and dynamical properties of dense cores and dense-gas outflows. | High-mass star formation | ISM and star formation | 2018-01-08T06:14:56.000 |
| 3255 | 2018.1.00222.S | 38 | Into the Heart of Darkness: Imaging a "Maximum Starburst" Nucleus at ~95pc Resolution in the First Billion Years | Cosmological simulations suggest that massive galaxies formed in the densest regions in the very early universe through hierarchical buildup, predicting the existence of massive protoclusters of intensely star-forming galaxies at high redshift. We have identified such a unique region within ~1 billion years of the Big Bang, hosting an extreme starburst and 14 normal star-forming galaxies. Advancing upon our highly successful efforts related to this region in cycles 0-5, we here propose to measure the detailed physical properties of the dust (i.e., the extinction-corrected brightness temperature, star formation rate surface density, and dust optical depth) in the hot (>49K), compact (<250pc), optically-thick nucleus of the best-studied unlensed starburst at z>5 (i.e., not limited by lens modeling accuracy) at rest-frame ~180um at ~95pc (15.5mas) resolution (and to obtain previously-approved short spacings data at ~70um). This unprecedented investigation of the exceptional central starburst in a rare galaxy protocluster at z=5.3 will critically constrain the extreme properties of starburst nuclei at such early epochs, which dwarf any galaxies in the present-day universe. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2020-10-01T23:06:55.000 |
| 3256 | 2013.1.01014.S | 28 | Low--Density Clouds on the Far--Side of the Galactic Center | The Central Molecular Zone (CMZ), i.e. the innermost ~200 pc of the Milky Way, contains a number of unusually dense and massive molecular clouds. Understanding the formation and evolution of these clouds is critical for many fields in astronomy, such as star formation under extreme conditions and clouds in starbursts and the early universe. The CMZ gas is organized in a roughly edge-on ring of ~100 pc radius. The near-side, as seen from Earth, contains ALL of the dense and massive CMZ clouds, while the gas on the far-side is rather unstructured. It has been suggested that this is due to the gravitational influence of Sgr A*, which is closer to the near-side. Here we explore why the far-side does not host ANY significant cloud. Are there clouds at all, or does the far-side essentially represent an unstructured turbulent flow? If there are clouds, how "old" are they, based on their dynamical state? Are clouds bound and evolving towards higher densities? This project produces the first resolved maps of far-side clouds. We will interpret the data in the context of our comprehensive Galactic Center Molecular Cloud Survey (GCMS). | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-05-14T00:00:00.000 |
| 3257 | 2023.1.00592.S | 415 | Characterizing the sulfur family in low-mass protostars | Sulfur-bearing molecules are commonly observed in both gas and ice near young protostars. Somewhere along the journey from diffuse cloud to protostar, the volatile sulfur budget is depleted by several orders of magnitude. A major uncertainty in this missing sulfur problem is where the sulfur-bearing molecules are being released from the ices and/or formed in high-temperature gas. Here, we propose 0.2-0.4" (30-60 AU radius) Band 6 observations of the main sulfur-bearing species (H2S, H2CS, CS, OCS, SO, SO2, and isotopologues) in six Class 0 and four Class I protostars. The combination of the requested spatial and spectral resolution will allow to disentangle the different physical components (e.g., disk+inner envelope, outflow). By observing optically thin isotopologues, the abundances in each component will be measured, giving a complete inventory of the gaseous sulfur-bearing molecules. These results will be combined with approved JWST/MIRI and NIRSpec programs containing information on the ice abundances and gas-phase atomic sulfur for the same sources. This will allow for the first time to accurately determine the amount of sulfur locked up in unobservable refractory formats. | Low-mass star formation, Astrochemistry | ISM and star formation | 2025-10-30T17:12:40.000 |
| 3258 | 2018.1.00992.S | 108 | A SUPER spatially-resolved assessment of the impact of AGN-driven outflows | We are conducting major surveys using integral field spectrographs in order to characterise the prevalence, properties and impact of ionised outflows. Our SUPER survey using AO-assisted IFS observations will provide key measurements of the ionised outflow kinematics and energetics for a sample of 39 z~2 AGN in unprecedented detail at this key epoch of galaxy evolution. Here we propose for ALMA Band 7 continuum observations to map the rest frame far-infrared emission at the same spatial resolution as our IFS observations (0.3"; ~2kpc) for an initial sample of 8 SUPER targets that span the range of observed outflow properties and host galaxy properties of the parent sample. Building on our previous ALMA results, we will use these observations to map the size and location of the star formation heated dust and compare to the location and size of the outflows (from the IFS data). Furthermore we will compare to the distribution of narrow Halpha emission, that has previously been used to trace star formation and claim suppression by outflows. Combined, these data will be a crucial to test of the prediction that AGN-driven outflows suppress star formation in their host galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-12-24T10:59:53.000 |
| 3259 | 2013.1.00623.S | 2 | ALMA Imaging of Bureid Active Galactic Nuclei Discovered by Hard X-ray Surveys | We propose to use ALMA to obtain 1''.6 resolution CO(2-1) and 1.2 mm dust continuum images of two "New-type" AGNs, ESO005-G004 and NGC 7172. The Swift/BAT all sky survey and subsequent X-ray follow up result in a discovery of a new class of AGNs, i.e., extremely heavily buried AGNs that exhibit very small fractions of scattered soft X-ray (only < 0.5%). Their SMBHs would be heavily embedded by geometrically thick tori with very small opening angles. A possible key mechamism to form and sustain such a geometrically thick structure is a starburst associated with the nucleus. Our goals of this program are then summarized as follows. (1) measuring the molecular gas mass (Mgas) and dynamical mass (Mdyn) in the central r < 130 pc region. We can assess the gravitational stability (or instability) of molecular gas by estiimating Mgas/Mdyn ratio because it can be related to the Toomore's Q value, and in fact star-forming galaxies tend to show high Mgas/Mdyn ratios (>0.1). (2) mapping the dust distributions. Off-plane dust emission, which is a signature of starburst, will also be surveyed. (3) searching for dense gas traced by CS(5-4); this is for free. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-12-12T07:54:52.000 |
| 3260 | 2017.1.00019.S | 46 | Outflow structure of the young protostar Lupus 3 MMS | We propose Band 6 observations of CO isotopologues and continuum to study the outflow of the Class 0 source Lupus 3 MMS. In Cycle 3 we mapped the Band 3 CO(1-0) line, and uncovered a bipolar outflow extending up to 2 arc-minutes in each lobe. The lobes have well-defined cavity walls and evidence for episodic ejection events. In Cycle 5 we propose complementary observations of CO(2-1) in order to achieve the observation goals of the original program, performed with the same angular- and spectral-resolution. This is required to permit accurate estimates of outflow physical parameters and structure by multi-line analysis of the optical depth and excitation temperature structure throughout the outflow, especially critical in shock regions. Utilizing 12 metre + ACA observations from CO(2-1) in Cycle 5 and CO(1-0) in Cycle 3 we can accurately assess outflow mass, momentum, and force. This is a particularly interesting source because accretion has only very recently begun, and we will use its outflow as a proxy for the accretion history, and thus permitting us to reveal the time-dependent aspects of accretion onto low mass protostars in the earliest evolutionary stage. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2020-02-18T00:00:00.000 |
| 3261 | 2019.2.00118.S | 12 | Detecting the molecular CGM around an AGN at z=2 | We request ACA observations of the CO(3-2) and [CI](2-1)+CO(7-6) line in correspondence of an X-ray selected AGN at z~2 that is part of the SUPER survey. Our previous ALMA and APEX observations of this source suggest the presence of molecular gas on scales of 40", corresponding to more than 300 kpc. We propose to use the ACA capability at its best to confirm and increase the S/N of such detection, which would be the first detection of molecular gas on scales of 100s of kpc in an isolated galaxy (i.e. not a protocluster), out to the boundary between the circumgalactic and the intergalactic medium. The combination of the proposed ACA observations with our previous CO(3-2) data (resolution ~1") obtained with the ALMA 12m-array will allow us to trace the molecular gas from the inner ISM-scales of a few kpcs out to scales of 100s kpc into the CGM, which is currently not available for any other galaxy at z~2. Furthermore, by combining these observations with our previous VLT/SINFONI observations of the ionised ISM and outflow in this target, we will study the link between kpc-scale outflowing features and the large-scale CGM. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-06-13T15:23:00.000 |
| 3262 | 2023.1.01010.S | 0 | Resolving the shock interacting regions in the Sgr B2 cloud with CH3OH Class I masers | Sgr B2 is the most active site of recent star formation in the Galactic Center. However, it is unclear what mechanism is responsible for such intense star formation. Cloud-cloud collisions, induced by existing expanding shells, could be triggering the intense star formation in Sgr B2. Recent Yebes 40m maps of the CH3OH 36 GHz line toward Sgr B2 show that this emission is extremely bright, indicating that it is a maser. Surprisingly, the emission is very broad (zero-intensity linewidths up to 150 km/s) and widespread across the whole Sgr B2 cloud. This emission may arise from the shock interacting regions in multiple cloud-cloud collisions induced by the multiple expanding shells. However, these shocked regions remain unresolved in the single-dish data. We thus propose to mosaic the CH3OH 36 GHz line with ALMA Band 1 towards Sgr B2 to establish the morphology, kinematics and physical conditions of the shocked gas in the cloud-cloud collisions. This information will allow us to derive the momentum and energy injected into the medium by these collisions, providing important constraints for star formation in the Galactic Center and for galaxy evolution models. | High-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3263 | 2013.1.00724.S | 2 | 1.1 mm Survey toward Distant Lensing Clusters of Galaxies | .We perform a gravitational lensing survey of Submillimeter Galaxies (SMGs) towards three distant clusters of galaxies selected from our ASTE/AzTEC observations. We will cover a total area of 10 arcmin^2 down to the 1 sigma sensitivity of 0.13 mJy at wavelength of 1.1 mm. The mean lensing amplification factor over the entire fields is about 7 and allows us to reach, on average, intrinsic fluxes of ~0.07 mJy at the 4 sigma significance, comprising effectively the deepest survey ever archived at this wavelength. The expected number of detections are 10-20 depending on the underlying source counts of SMGs. This will not only enhance the current sample of lensed SMGs detected with ALMA by a factor of 2-3, but also provide a useful probe on its faint-end shape at ~0.1 mJy. Once combined with existing single dish data from ASTE/AzTEC, the data will further provide us the first source-free Sunyaev-Zel'dovich effect (SZE) increment images of galaxy clusters. | Sub-mm Galaxies (SMG), Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE) | Galaxy evolution | 2016-05-21T06:15:17.000 |
| 3264 | 2024.1.01740.S | 0 | NOSH: The Neutral Oxygen Survey at High-z | We propose completing the Neutral Oxygen Survey at High-z, NOSH, using 30.7 hours of ALMA 12-m array time to observe the [OI] 145 micron line in 23 galaxies with existing [CII] 158 micron detections between z ~ 3 and 7.2. We recently detected the [OI] line in three NOSH sources, and seek time to finish the survey of 26 high-z galaxies. The [CII] and [OI] lines are primary coolants of the warm neutral-medium in galaxies. The [CII] line has been observed in hundreds of high-z galaxies, but complementary [OI] observations are missing. NOSH will provide these missing [OI] observations for sources that fully span the observed [CII]/FIR ratios. Combining NOSH [OI] detections with the existing [CII] detections is a unique probe of the ISM in galaxies, letting us constrain the total gas cooling, gas density, far-UV field strength and spatial extent of star formation in each source. We will reveal whether star formation in NOSH sources is compact--powered by mergers--or extended with large gas reservoirs and gas accretion. The wide redshift coverage of NOSH lets us trace evolution of these galaxy properties across cosmic time, providing important new insights into galaxy growth. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2025-10-23T20:35:45.000 |
| 3265 | 2023.1.00225.S | 0 | Tracing evolution of dense core nucleus in ortho-H2D+ | To reveal the dynamical/chemical state just before/after the protostar formation has been one of the long-standing challenges. There are two main difficulties in this study: one is the lack of suitable targets due to an extremely short lifetime of the relevant objects, and the other is the limitation of molecular lines which are adequate for tracing very dense medium whose central density exceeds ~10^6-7 cm^-3 where most of the high-density tracers are depleted onto dust grains. We have carefully selected three dense cores with the different evolutionary stage from Taurus as the observation targets based on the ALMA archival data and the literature, L1544 (prestellar core), MC35-mm (first hydrostatic core candidate), and L1521F (protostellar core containing a very low-luminosity Class 0 protostar). Theoretical efforts in the past few decades have suggested that the ortho-H2D+ line at the Band7 frequency is desirable to look into the core nucleus avoiding the effect of significant depletion. Our proposed ACA observations will elucidate the full extent of the molecular emission and kinematical structures throughout the evolutionary stage bridging pre and protostellar cores. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-10-04T15:14:08.000 |
| 3266 | 2011.0.00005.SV | 0 | Science verification observation of SgrA* | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Galactic centres/nuclei, Spiral galaxies | Active galaxies | 2016-06-24T14:02:06.000 |
| 3267 | 2021.1.00095.S | 1784 | Searching for massive starless core candidates in proto-stellar clusters | Whether massive starless cores exist or not is crucially important to test different models of high-mass star formation. Very massive (M>30 Msun) starless core candidates have been found in some case studies of evolved proto-stellar clusters, which may represent the very initial conditions of high-mass star formation. However, systemic searching for starless cores in proto-stellar clusters, has not been done yet. To this end, here we propose high resolution ALMA band 6 observations of a 140 high-mass proto-stellar clusters. We aim: (1) to search for candidate massive starless cores; (2) to study core mass growth by comparing the core mass functions (CMFs) for starless cores and for proto-stellar cores; (3) to investigate the effect of stellar feedback on core properties. Only through observing such a large sample one can figure out whether or not massive starless cores are common in proto-stellar clusters and what their properties are. The data will be used in the thesis works of several PhD students. | High-mass star formation | ISM and star formation | 2024-02-08T20:17:57.000 |
| 3268 | 2011.0.00648.S | 0 | Molecular gas/dust and gas metallicity in star-forming galaxies at z~1.4 | We propose CO(5-4) and dust thermal continuum emission from star-forming galaxies at z~1.4. The sample contains 20 star-forming galaxies extracted originally from our stellar mass limit sample. From usual spectral energy distribution analysis, stellar masses and star-formation rates (SFRs) of these galaxies are obtained. Subsequent near infrared spectroscopy enabled us to derive gas metallicity from Halpha and [NII] emission lines, and extinction corrected Halpha luminosity for the targets. With this unique sample, we will investigate whether the molecular gas mass and the dust mass as well as CO-to-H2 conversion factor at the redshift show some trend against gas metallicity rather than stellar mass, SFR, etc. Since there is a possibility that CO luminosity at a given molecular gas depend on the gas metallicity and dust mass is also expected to be dependent on metallicity, studies of star-forming galaxies covering a certain range of metallicity, stellar mass, and SFR is inevitable to push further high-z CO/dust observations in general. Furthermore, since gas inflow/outflow also affects gas metallicity evolution, we will be able to constrain a process of galaxy evolution from the metallicity and the gas mass fraction. The results obtained in this proposal are expected to give us a good compass to navigate future high-z observations with ALMA. Thus the program would be suitable to be conducted in cycle 0 phase. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2013-12-03T00:34:00.000 |
| 3269 | 2016.1.01103.S | 703 | The core mass function in a far-outer Galaxy cloud | The distribution over mass of stars at birth, the stellar initial mass function (IMF) is one of the most important parameters in star-formation research. It is still not clear what determines the IMF, nor whether the IMF is the same for every star forming region. It does seem, however, that the IMF is set very early on by the masses of the molecular cores out of which the stars form. The core mass function (CMF), and by consequence the IMF, may however depend on the physical and chemical properties of the environment. So far, CMFs (and IMFs) have been determined in molecular clouds (and star clusters) in the solar neighborhood and the inner Galaxy. We propose to determine the CMF in a molecular cloud in the far-outer reaches of our Galaxy (R=16 kpc), where conditions are very different from the inner Galaxy. We do this by continuum (and line) observations of 94 clumps identified from Herschel 250 micron images of this cloud; each clump is assumed to contain one or more cores, of sizes comparable to the ALMA beam. We aim to detect cores with masses of the order of the Jeans mass (1 Msun). Resubmission of 2015.1.01235.S (gradeC). In April 2016 42 targets were observed; awaiting QA2. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-02-28T19:59:48.000 |
| 3270 | 2021.1.01571.S | 20 | Establishing HF as a robust molecular outflow tracer for high redshift galaxies | We propose to establish HF as a robust molecular outflow tracer in luminous star-forming and active galaxies at high-z. HF is the most sensitive sub-mm absorption line molecular gas tracer in galactic sightlines and has successfully traced molecular outflows in star-forming and active galaxies at low and high-z. Previous ALMA programs have established OH+ as a sensitive neutral atomic gas outflow tracer at z=2-4, in both dusty star-forming galaxies (DSFGs) and quasars, the predecessors of massive low-z quiescent galaxies, revealing strikingly more extreme neutral gas outflows in DSFGs. We thus propose a pilot program targeting molecular gas, known to dominate the mass budget of low-z black-hole driven winds, with HF in 4 high-z DSFGs and quasars. We will determine if high-z quasar outflows truly are weaker than their DSFG contemporaries, as suggested by OH+, or if the molecular gas fraction is simply higher, as seen at low-z. Total cold gas masses, the dominant phase in galaxy outflows, will be measured, allowing analysis of the full impact of outflows during this critical phase of galaxy evolution, motivating future more extensive multiphase projects currently absent at high-z. | Outflows, jets, feedback | Active galaxies | 2024-09-29T16:44:15.000 |
| 3271 | 2019.1.00761.S | 7 | Detection of a circumbinary disk around the high-mass protostar G 014.23-00.50 showing periodic flux variability | We propose continuum and CH3CN/SiO thermal line observations in band 3 to detect a circumbinary disk around the high-mass protostar (HMP) G 014.23-00.50, which has shown flaring flux variations with the period of 23.9 days (the shortest so far). The evolutionary sequence of HMPs is still under debate because the mass accretion rate onto the stellar surface, where is directly unreachable tiny area even with ALMA, is the most significant factor to define evolutionary tracks. To understand the accretion rate in such a tiny area, periodic flux variability observed mainly in CH3OH masers around HMPs is the most powerful probe in terms of its time-scales from a few tens to a few hundreds days, corresponding to the spatial scales of 0.1-1 au (e.g., under the condition of Keplerian rotation). The periodic flares in the target source G 014.23 might be explained by a variation of the dust temperature at the maser emitting region on a circumbinary disk. As the first step in series to challenge flux monitor observations with ALMA in the next cycle, here we would like to detect a compact and spatially resolved object with evidence of a binary, which could be interpreted as a circumbinary disk. | High-mass star formation | ISM and star formation | 2022-12-16T10:29:46.000 |
| 3272 | 2019.1.00634.S | 27 | AGN feedback in 3C273, the nearest radio loud quasar | Extended emission line regions (EELRs) in QSOs are a direct measure of how much energy from the AGN is used to heat the host ISM. Detailed studies of when, where and how much ionization takes place, however, has been difficult because narrow-band optical imaging suffers from dust extinction, uncertainties in assumption of gas properties, and the extremely bright QSO core that overwhelms the diffuse emission. Using the ALMA archive, we have detected extended 3mm continuum in 3C273, the nearest radio-loud QSO. The detection, presumably thermal free-free bremsstrahlung, could be an extinction-free and straightforward measure of the ionized gas making up EELR. We request dedicated band 6 and 7 continuum observations to subtract from 3mm the contribution of dust and free-free emission due to massive SF. The proximity of 3C273 will reveal the true extent of gas directly ionized by the AGN, and further enable investigation of whether the putative EELR was created 10^5 yr ago together with the jet, and if star formation is actually quenched due to AGN feedback. The results will be a benchmark for high-z observations of EELRs. | Outflows, jets, feedback | Active galaxies | 2021-03-13T09:40:37.000 |
| 3273 | 2018.1.00135.S | 158 | Extra-planar & Diffuse Molecular Gas in Spiral Galaxies | Extra-planar layers in spiral galaxies are the interface between the IGM and star-forming disk and are essential for understanding disk-halo flows. They have been studied extensively for all ISM phases with the exception of molecular gas. All other ISM components show extended extra-planar material, most connected to star formation. It remains to be seen if this is true for the molecular component. Recent observations have found evidence for diffuse extra-planar molecular layers. These studies, however, were completed for face-on or moderately-inclined galaxies, and thus unable to fully-constrain their heights. Ideally, extra-planar layers are observed edge-on. Such observations have been performed for only 3 galaxies and show strikingly different results. Thus, a larger samples are needed to truly understand this phenomenon. We began with our Cycle 4 pilot study of NGC 55 and aim to expand our sample to include galaxies with a range of star formation rate densities. Using the unique power of the ACA, we will map the vertical extent of CO, a strong tracer of molecular gas. | Spiral galaxies | Local Universe | 2019-10-12T12:53:58.000 |
| 3274 | 2017.1.01232.S | 28 | Spectral line survey in the rest-frame 350 GHz band toward the Cloverleaf quasar | Here, we propose a spectral line survey in the rest-frame 350 GHz band toward the high-redshift "Cloverleaf" quasar at z=2.56. Thanks to the increasing sensitivity of radio telescopes, unbiased spectral line surveys have been conducted toward nearby galaxies, and usefulness of chemical diagnostics has been demonstrated. For instance, tracers of large-scale shock such as CH3OH are prominent in galaxies in early starburst phase. Lessons learned from nearby galaxies tell us that chemistry in high-redshift galaxies must have rich complexity and will bring us unique information on physical properties. Hence, we aim to reveal the chemical composition of the Cloverleaf for the first time and characterize it by comparing with those of nearby galaxies. Because the Cloverleaf has exceptionally bright CO and HCO+ emissions amplified by gravitational lensing, it is considered to be the best candidate. In our frequency settings, dense gas tracers (CO, HCN, HCO+, HNC, and CS), tracers of UV radiation field (CCH and CN), and tracers of shock (CH3OH and SO) are included. This observation will constitute the first template of the chemical composition of high-redshift galaxies. | Galaxy chemistry | Galaxy evolution | 2019-04-27T23:51:08.000 |
| 3275 | 2015.1.01260.S | 3 | What lies beyond Exo-Jupiter planets? | We propose to image the debris disk of the nearby Gyr-old main sequence F9 star q1Eri in band 7 to determine the disk structure at a resolution (0.7", 12au) ~8 times better than previous imaging. This system hosts an Exo-Jupiter planet at 2au on a low (but potentially non-zero) eccentricity orbit. It also hosts a moderately asymmetric debris disk at ~100au which could be eccentric or clumpy. The lack of (anti-)correlation between systems with Exo-Jupiters and those with debris is surprising given predictions of formation scenarios in which Exo-Jupiters become eccentric through dynamical instabilities. Imaging the debris disk of a system where both are present will throw light on what lies in the empty region 2-70au which holds clues to the formation of Exo-Jupiter systems and their lack of correlation with outer debris. We will determine the origin of the disk's asymmetry as well as the radial distribution of material. Models are in place to interpret observed structure in terms of unseen outer planets and various formation scenarios. The proximity and sub-mm brightness of q1 Eri makes it the premier laboratory for understanding the class of Exo-Jupiter planetary systems. | Debris disks, Exo-planets | Disks and planet formation | 2019-08-28T10:12:01.000 |
| 3276 | 2023.1.00367.S | 0 | CONICS: Cosmic Noon ISM Conditions Survey | The COsmic Noon ISM Conditions Survey (CONICS) is a comprehensive survey of the mass and conditions in the cold interstellar medium (ISM) of 11 star-forming galaxies during the peak of cosmic star formation (z=2-3). Carefully drawn from optically-selected CO(3-2) surveys, these galaxies form the largest representative sample of star-forming galaxies at this epoch and benefit from exquisite multi-wavelength data. With only two tunings, we will efficiently measure the CO(4-3)+[CI](1-0) and CO(7-6)+[CI](2-1) emission and underlying dust continuum in Bands 4 and 6, providing a homogeneous dataset that is sufficient to constrain the latest generation of radiative transfer models of the cold medium. This program will provide fundamental insights into the boundary conditions for star formation during the peak of the cosmic star formation history by measuring (i) the total mass in cold gas and dust (ii) the physical conditions in the cold molecular medium (e.g., temperature, density). Building on years of investments with ALMA and NOEMA, CONICS will provide the most comprehensive survey of the gas masses and ISM conditions in galaxies at cosmic noon to date. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2025-01-24T15:22:03.000 |
| 3277 | 2022.1.00472.S | 14 | ALMA Observations of the Shocked Gas in the Puppis A Supernova Remnant | Investigating the interaction between the supernova shock waves and surrounding interstellar gas is essential in understanding evolutionary tracks from the neutral molecular clouds to hot plasma, which affect both star formation and evolution of the interstellar medium. We here propose to observe shocked molecular clouds in the supernova remnant Puppis A, which are rim-brightened in the X-ray emitting plasma. Since the plasma parameters (electron density, temperature, and shock elapsed time) have changed dramatically around the shocked molecular clouds, Puppis A is the best target to unveil the mechanism of hot gas production. However, we could not establish the relation between the plasma parameters and neutral cloud distributions due to the modest angular resolution (~23 arcsec), sensitivity, and the sparse observing coverage in the current datasets. The proposed ALMA ACA observations of CO(J = 2-1) at resolutions of 6 arcsec (~0.06 pc at the SNR distance) will allow us to study the relation between the shock-survived molecular clouds and hot plasma at a meaningful spatial scale. ALMA is the only telescope array to fulfill such requirements. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-05-08T00:00:00.000 |
| 3278 | 2017.1.01600.S | 2 | Measuring an Emprical Temperature Structure for the HD 163296 Disk | Gas surface density and temperature profiles are among the most fundamental properties of a protoplanetary disk. These profiles regulate almost all observable characteristics of the disk, and therefore their accurate characterization has long been a goal of both disk observations and theory. In particular, poorly constrained parametric temperature structures are currently proving to be insufficient for interpretation of ALMA data, limiting progress on constraining disk properties such as turbulence. Observations of optically thick lines can break the degeneracies of parametric temperature structures, directly yielding the radial temperature profile of their emission surface layer. Furthermore, in an inclined disk these observations can be used to probe in the vertical direction, with a directly observable opening angle for each emission surface. We propose to exploit these properties and constrain the 2-D (radial and vertical) temperature structure of the HD 163296 disk by observing multiple transitions of optically thick CO isotopologues. Our results will provide the first fully empirical temperature structure for a protoplanetary disk. | Disks around high-mass stars | Disks and planet formation | 2020-01-22T20:12:50.000 |
| 3279 | 2015.1.00656.S | 34 | Testing Basic PDR Physics in Carina's Western Wall | One of the most basic predictions from models of molecular cloud structure is that a layer of warm atomic gas (the photodissociation region or PDR) separates H II regions from molecules located deeper within a dark cloud. With the commissioning of ALMA's Band 8 this Cycle, it will be possible to image PDRs in atomic C at subarcsecond spatial resolution for the first time, easily resolving the spatial offset between C I and H2, and perhaps also between C I and CO. Our target is the Western Wall in Carina, one of the brightest and geometrically simple PDRs in the sky. By combining the ALMA images with existing H2 and Br-gamma images, we will be able to trace the gas as it transitions from the H II region into the depths of the molecular cloud. The CO and C I maps will also uncover density enhancements along the PDR interface and within the molecular cloud, a crucial constraint for models of triggered star formation. The proposed frequency settings include J=2-1 lines of 12CO, 13CO, C18O in Band 6, and C I and CS in Band 8. The resulting composite images should be stunning, and generate a textbook-like example of the most fundamental concept in PDR physics. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR), HII regions | ISM and star formation | 2017-09-15T19:57:49.000 |
| 3280 | 2023.1.00626.S | 0 | Spatially Resolving Dust Obscured Star Formation | We propose a 30 hour deep spatially resolved study of HST-dark sources with ALMA Band 6 in the A2744 cluster field. Over 70 hours of ultradeep JWST imaging (29-30AB at 1-5um) have already been collected as a part of UNCOVER survey, with further MSA NIRSpec observations covering the highly magnified 4'x6' area scheduled for mid 2023. The same area has been covered by deep (38-60uJy) ALMA Band 6 continuum observations, yielding N~60 lensed continuum sources. Our proposed observations will target 33 of those ALMA continuum galaxies, also detected by JWST. We will: 1) Spatially resolve (0.1"-0.3") the substructures identified with JWST and bridge the gap between the bulge-forming starburst and the rest of the galaxy; 2) Use spatially resolved optical to sub-mm photometry to characterize dust morphology, spatially resolved sub-mm SFR, dust extinction and dust surface density; 3) Uncover the mechanisms responsible for dust emission in galaxies, such as mergers, and test whether the existence of the so called optically faint population is a matter of galaxy inclination. Due to lensing our study only takes 30 hours to execute as opposed to >100 required for field galaxies. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2025-02-20T15:57:20.000 |
| 3281 | 2024.1.01075.S | 0 | Dust and Star formation in the Hosts of Quasar Jets Caught Switching On | We propose an ALMA Band 7 imaging study of the rest-frame FIR emission of a unique sample of quasars that were recently caught launching newborn jets by the Very Large Array Sky Survey (VLASS). The targets are powerful quasars that have transitioned from radio-quiet to radio-loud in the past 10-20 years. Multi-wavelength follow-up observations in the radio and X-ray probing the jet and accretion properties are underway, but the properties of the host galaxies remain unknown. Our main goal is to investigate the interstellar medium (ISM) masses/morphologies and constrain the star formation rates (SFRs) of the hosts of quasars with newborn jets. This study will be the first to explore the dust and SF properties of quasars selected in the radio time domain as candidate newborn jets. We require the ALMA 12m-array, and emphasize that it is the only instrument in the world capable of resolving the 870 micron emission on kpc scales. Our proposed observations will ultimately pave the way for continued studies of jets in their youth as VLASS progresses over the next few years and catches more jets switching on. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2025-10-25T18:14:49.000 |
| 3282 | 2012.A.00041.S | 0 | A new solar system planet or brown dwarf discovered with ALMA? | Recent ALMA observations of the evolved star W Aql (2012.1.00524.S, PI Ramstedt) revealed a curious bright source (3 mJy/beam, detected at 7.5sigma-significance) in two subsequent epochs separated by 25 days. During this time, the source has moved by almost 6 arcseconds. At only 1 pc this would correspond to a velocity more than 400 km/s making a location nearer to the Sun more likely. We might thus have discovered a rather bright submillimeter source at sub-pc distance. No similar object has previously been observed. Keplerian rotation alone would put the object around 600 AU and a typical brown dwarf velocity would put it at only 0.02 pc. The most intruiging option is that ALMA has discovered a large planetary body or brown dwarf near the Oort cloud. We request ALMA DDT observations to confirm or reject this hypothesis. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2015-01-07T23:03:52.000 |
| 3283 | 2013.1.00367.S | 1 | What is heating the Orion-KL hot core?: The explosion, the bubble or Source I | This proposal aims to find what is heating the Hot Core in Orion KL. We want to reveal the distribution of the highly excited lines at 650 GHz with a high angular resolution (0.2''). The line distribution of such lines will help in understanding which of the outflows in Orion KL are exciting the hot core: the explosion, the bubble or the outflow from source I. Additionally, we will distinguish previously unseen structures, characterize the weak line wing emission, and reveal the true (sub)millimeter sources located within the region. These observations very likely will reveal totally new features of the Orion KL hot core, and show for the first time the kinematics and identify the origin of the highly excited molecular gas at very small scales. | Intermediate-mass star formation | ISM and star formation | 2015-11-12T19:58:19.000 |
| 3284 | 2022.1.00353.S | 51 | A Pilot Study of Warm Molecular Gas in High-redshift Obscured Quasars | We request ALMA observations of the CO(J=7-6) transition in a small sample of 5 high-redshift (z>~3), hyper-luminous (Lbol > 10^14 Lsun), dust-obscured quasars for which at least two other lower-J CO line transitions have already been detected with ALMA and VLA. This is a pilot program motivated by a surprisingly bright detection of the CO(J=12-11) transition in the most luminous obscured quasar known, W2246-0526, which suggests that it is possible to detect mid-J CO transitions in these extreme objects at high-z with very short integration times. The goal of this project is two-fold: (1) to start investigating the excitation properties of the warm molecular gas in high-z obscured quasars and place them in context with other dusty galaxy populations, and (2) to determine whether the CO(J=7-6) line, which has recently been proposed as a good star formation rate indicator, can be truly used in galaxies hosting extreme environments. This will be the first time that such a study is conducted in this population of high-z quasars. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2023-12-28T17:18:18.000 |
| 3285 | 2015.1.00463.S | 46 | Exploring the Earliest Epoch of the Massive Dust Production | Recent ALMA observations have detected the strong dust continuum in A1689-zD1, a lensed LBG at z=7.5. Theoretical studies indicate that the dust mass of A1689-zD1, ~4x10^7 Mo, is too great to be produced at such an early cosmic epoch in conventional dust grain growth scenarios, and thus a new mechanism of efficient growth over a very short accretion time scale may be required. Here we propose deep Band 6 observations to detect the dust continua of 7 red LBGs at z~7-8 that are the best mm-bright dusty LBG candidates among our large sample of 1012 LBGs at z~6.5-9 drawn from most of the major Hubble survey data, available to date. Our goals are to evaluate how common dusty LBGs at z~7-8 are, as the first step in statistical studies, and to search for the earliest dusty LBGs to provide improved constraints on the efficiency of the early dust production. Because two of our targets reside within the highest overdensity region of z~8 LBGs so far identified, our program will also investigate whether dust grain growth is an environmentally-dependent process. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2017-07-29T07:30:17.000 |
| 3286 | 2018.A.00058.S | 312 | ACA CO(2-1) mapping toward the nearest spiral galaxy M 33 | The understanding of the evolution of giant molecular clouds (GMCs) is one of the most fundamental issues in modern astronomy. Recent ALMA observations suggest that the formation of dense molecular gas and the growth of pc-scale filamentary structures play important roles in the evolution of GMCs. We propose to observe 12CO(2-1) and 13CO(2-1) emission lines over the molecular gas disk of the nearest spiral galaxy M 33 with the ACA stand-alone mode. Based on the ACA CO(2-1) maps at a spatial resolution of 27 pc, we identify more than 300 GMCs in M 33, and examine their 13CO(2-1)/12CO(2-1) intensity ratio and line widths of 12CO(2-1) and 13CO(2-1) emission. The 13CO(2-1)/12CO(2-1) intensity ratio is sensitive to molecular gas density and the line width of 13CO(2-1) may trace gas kinematics such as cloud-cloud collisions. Thus these two parameters, reflecting the dense-gas formation and the internal kinematics within the GMC, seem to be good indicators to estimate the evolutionary stage of the GMC in detail. Furthermore, the proposed GMC survey in M 33 with ACA provides the fundamental data to plan high-angular resolution observations toward individual GMCs with ALMA 12-m array. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2021-01-16T00:00:00.000 |
| 3287 | 2012.1.00039.S | 0 | Dissecting the cold dust in the most massive AGN hosts | Using Spitzer, Herschel, SCUBA and LABOCA, we have obtained 12-band 3.6 to 850um photometry of 71 radio galaxies covering 1 | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2015-05-08T14:12:39.000 |
| 3288 | 2011.0.00007.SV | 0 | Science verification observation of IRAS16293 | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Low-mass star formation, Astrochemistry | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3289 | 2013.1.00470.S | 8 | Resolving the star-forming ISM at z~2-3 | We propose resolved (0.45”), matched-resolution mapping of the CO, [CII], and underlying dust continuum in a carefully selected sample of z~2-3 galaxies in the ECDFS. The proposed targets were drawn from our Cycle 0 870um survey of >100 sub-mm galaxies (SMGs), the largest, most homogenous, and best-studied sample of interferometrically observed SMGs to date. Our recently completed spectroscopic follow-up campaign has allowed us to meticulously identify 4 SMGs with redshifts that allow us to observe both low-J CO and [CII] with ALMA. In addition to providing tight constraints on gas masses, SF efficiencies, kinematics, and PDR models, these observations will reveal the fundamental relationship between molecular gas and star formation (`Kennicutt-Schmidt law') on ~kpc scales. Critically, they will also allow us to test how well [CII] correlates with the cold molecular gas reservoir probed with CO. This is imperative, as [CII] will be the main line for studying the star-forming ISM at even higher-z. These detailed case studies, which are only now becoming possible with ALMA, are an essential complement to larger statistical studies of individual tracers and integrated properties. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2016-11-05T12:35:12.000 |
| 3290 | 2021.1.01369.S | 57 | Dissecting the H/H2 and C+/C/CO transitions of a prototypical PDR: ALMA and JWST observations of the Orion Bar | Bright PDRs in nearby star-forming clouds are the best laboratories to study the detailed structure, physics, and dynamics of UV-illuminated matter in the ISM. However, recent high-angular observations of the prototypical PDR, the Orion Bar, cannot be explained by "standard" 1D PDR models. This challenges their applicability to interpret the PDR emission from related environments (from disks to galaxies). We propose a combined ALMA and JWST-ERS study (data available in fall 2022) to spatially resolve - for the first time at sub-arcsec resolution - the structure of all relevant transition zones of this textbook PDR: from the HII/cloud interface to the H/H2 and C+/C/CO transition zones. Only ALMA can resolve the emission from the main carbon reservoirs C+, C, and CO, and constrain the unknown exact location, width, and kinematics of these zones (i.e., probing the conversion from atoms to molecules and the photo-erosion of PAHs and grains). These are crucial ingredients to benchmark a new class of models able to simulate the 3D and dynamical nature of PDRs. We request small mosaics of the [CI]492GHz, 13CO and C18O 3-2, C2H 4-3 lines, and of the C42a and H42a recombination lines. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2023-10-06T19:59:24.000 |
| 3291 | 2017.1.00121.S | 5 | Constraining Jupiter's atmospheric chemistry and dynamics from H2O mapping in ALMA band 5 | In July 1994, comet Shoemaker-Levy 9 (SL9) spectacularly impacted Jupiter at 44°S. On the long term, Jupiter was left with a variety of new species in its stratosphere: H2O, CO, HCN, CS, and CO2. Their distributions have been monitored, generally with poor spatial resolution. In Cycle 4, we successfully mapped the HCN and CO distributions in Jupiter in band 7 with an angular resolution of 1.1". To complement our successful Cycle 4 project, we propose to map H2O in band 5 in Jupiter with an ALMA+ACA+TP mosaic. With a resolution of 1.9" (i.e. a Jupiter image of ~20x20 pixels), we will reach an unprecedented high latitudinal resolution. We aim to: 1) Derive the meridional distribution of H2O to better understand Jupiter's atmospheric chemistry and dynamics. 2) From the combination of the H2O map and our Cycle 4 maps of CO and HCN, understand why CO and HCN have such different meridional distributions, when both are thought to originate from SL9. 3) Identify a potential exogenic source of oxygen at auroral latitudes. 4) Constrain Jupiter's meridional dynamics by modeling in 3D (altitude-latitude-time) the evolution of the post-SL9 species distributions over ~20 years. | Solar system - Comets | Solar system | 2019-12-07T16:48:34.000 |
| 3292 | 2015.1.00333.S | 4 | Establishing the Disk Mass-Stellar Mass Scaling Relation | A fundamental parameter of every planet formation is the disk mass. Indeed, the occurrence rate of exoplanets shows trends that are likely the result of stellar mass-dependent disk masses. We propose to measure the masses of all Chameleon I disks around objects from ~2 to 0.05 solar masses in order to: 1) establish how the disk mass scales with the mass of the central star and 2) constrain average disk masses and their spread over a range of 40 in stellar mass. We were awarded ALMA Cycle 2 time for this survey but only one of our two SBs, the one comprising 54 stars with masses >= 0.3 solar masses, has been executed. This limited dataset hints that the disk mass-stellar mass relation is steeper than linear but the SB with the 39 lower-mass objects is necessary to reach our science goals. Here, we request observation of that SB, as well as re-observation of 14 M-K stars, 7 of which are ~0.3 solar mass stars, at the same sensitivity as for the lower-mass objects. Our survey, in combination with ancillary data we are assembling, will also test disk dispersal theories and provide an ALMA legacy for follow-up studies of disks around young stars. | Disks around low-mass stars | Disks and planet formation | 2017-07-01T00:32:53.000 |
| 3293 | 2023.1.01135.S | 0 | The Demographics of Molecular Gas in Dwarf Galaxies with AGN | A comprehensive understanding of the co-evolution of supermassive black holes and galaxies requires a close examination of the molecular gas content, which is the fundamental fuel for not only star formation but also Active Galactic Nucleus (AGN) activity. Meanwhile, AGN feedback may also directly impact the molecular gas content in the galaxy. While current studies have carefully mapped the molecular gas content in the massive host galaxies of luminous AGN, little is known for dwarf galaxies with AGN. In addition, tantalizing evidence of AGN feedback in dwarf galaxies is also rapidly emerging. To shed light on these issues, we propose to systematically examine the molecular gas content of nearby dwarf galaxies with AGN by searching for CO(1-0) emission in them. We will explore the connection between the AGN properties and molecular gas properties, investigate whether the molecular gas properties of the dwarf galaxies with AGN are systematically different from those without AGN, and search for molecular gas outflows. This information will allow us to evaluate how the feeding of AGN may depend on the molecular gas supply, and how the AGN feedback may impact it. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-01-17T03:25:26.000 |
| 3294 | 2017.1.00239.S | 156 | What sets CO excitation in clumpy, turbulent disk galaxies? | The CO(1-0) emission line is very difficult to observe at z>1. This creates large uncertainties in studies of galaxy evolution as high-redshift observers use J=3,4,5 transition lines to trace CO and then must make assumptions about the CO spectral line energy distribution to deduce the total molecular gas mass. There is currently no simple template for CO line ratios (or CO SLED) that can be applied to all high-redshift main-sequence galaxies. We propose to use the DYNAMO sample to observe CO(4-3) and CO(3-2) in a sample of galaxies for which we have already obtained CO(1-0), as well as have high resolution emission line maps from Hubble Space Telescope and Keck. Our goal is to determine exactly how these line ratios change as the galaxies become more dominated by clumps, have higher star formation rate surface densities and more turbulent kinematics. These observations will both directly test theories of ISM that predict CO excitation, and compliment major investments of ALMA time as high-z observers will be able to easily convert mid-J CO lines to global gas mass using a small number of physical parameters, such as SFR surface density and gas fraction. | Starbursts, star formation | Active galaxies | 2019-07-03T15:12:31.000 |
| 3295 | 2016.1.00071.S | 6 | Revealing the importance of magnetic fields in the earliest stages of the formation of high-mass stars | Theory predicts that the role of the magnetic field is significantly important in the prestellar phase of high-mass star formation. Some models suggest that the B-field in the prestellar cores will suppress fragmentation and add support against gravitational collapse, allowing the formation of high-mass stars. However, observations of the B-field have never been possible in this kind of sources due to the weak emission of cold dust. Using a 3D radiative transfer model customized for our targets, we predict a polarization fraction of 3%, which can only be detected by ALMA. For the first time, we will determine the B-field direction, morphology, and strength in two carefully selected prestellar, high-mass cores by using dust polarized emission at 345 GHz. We will (1) compare the direction of the field from small to large scales, using NIR K-band polarimetric observations, (2) apply the Chandrasekhar-Fermi method to derive a B-field strength to test models of high-mass star formation, and (3) test the predicted polarization degree by radiative alignment torque (RAT) theory. This would be the first study of this kind that can serve as a template for future larger samples. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-05-30T02:29:11.000 |
| 3296 | 2022.1.00700.S | 150 | The Formation of High-Mass Binaries and Their Accretion Disks | High-mass stars (>8Msun) are preferentially found in binary systems. So far, there are no definitive observational constraints to identify which are the dominant physical mechanisms explaining the binarity of high-mass stars: core fragmentation, disk fragmentation, and/or multiple-body interactions. At the same time, the evidence of (Keplerian) accretion disks around high-mass stars is growing. However, no systematic study at the required spatial resolutions to resolve disks (<100 au) have been carried out. Based on the experience gained in a pilot survey and taking advantage of the unique ALMA capabilities, we will statistically (1) test the scenarios that explain the binarity of high-mass stars, and (2) search and characterize accretion disks around high-mass stars. Using dust continuum at ~230 GHz and including several tracers of disk kinematics (hot core, salt, and recombination lines), we will observe a uniform sample of 71 high-mass star-forming regions between 2 and 3 kpc, reaching an unprecedented spatial resolution (~50 au). We estimate to unveil ~100 binaries containing massive young stellar objects (MYSOs), factor 5 larger than in the pilot survey. | High-mass star formation | ISM and star formation | 2024-08-16T21:00:04.000 |
| 3297 | 2016.1.01186.S | 39 | Resolving disk instabilities and polarization at 10 au scales | ALMA long baseline observations have opened a new window toward the study of protoplanetary disks. The high resolution data reveal asymmetries on the surface brightness of disks, which have been sucessfully modeled as vortices or spiral shocks formed by gravitational instabilities. In Cycle 2, our team was granted observations toward the Class I object BHB07-11, in the Pipe nebula. The data revealed striking substructure: a pronounced asymmetry in the dust emission, kinematical variations across the disk and bright polarization. The disk asymmetry strongly suggests a new timescale for the formation of vortices, given that up to now they were observed only in transitional disks. The kinematics show an offset of 150 au between the outflow and the disk, while the polarization has a remarkable ordered pattern. This source offers an enourmous potential for further observations with ALMA. We propose polarization observations in order to characterize the polarization as scattering or grain alignment, and we propose high resolution observations that will show which kind of instability is happening in the inner disk, and how the kinematics is affected by such processes. | Disks around low-mass stars | Disks and planet formation | 2018-06-21T18:25:04.000 |
| 3298 | 2012.1.00698.S | 0 | Dynamically Fingerprinting HD141569's Protoplanetary Disk: A Testbed For Planet Formation and Disk Evolution Theories | We propose to observe the dynamic protoplanetary disk surrounding HD141569 to test models for the origins of debris disk structures and to place strong constraints on planet formation on wide orbits. HD141569 has a complex radial and aximuthal morphology at opitical wavelenghts, contains gas as well as debris, and appears to be in the final throes of planet formaiton. The system is in a rare stage, transitioning from gas to debris dominated, making the system a unique testbed for planet formation and disk evolution theories. | Debris disks, Exo-planets | Disks and planet formation | 2015-08-13T13:58:04.000 |
| 3299 | 2015.1.01090.S | 27 | Unique high resolution &multi-wavelength study of a z=1.4 quasar host galaxy | An understanding of the physical mechanisms and connections between supermassive black hole growth and galaxy formation and evolution remains elusive. One reason for this slow progress is the difficulty associated with studying host galaxies of distant luminous quasars, due to the high contrast required to separate the faint, resolved galaxy from the bright quasar. ALMA observations in the submm and adaptive optics assisted near-infrared integral field spectroscopy (IFS) observations allow for sufficient contrast to study quasar host galaxies on a sub-kpc scale. The two types of observation complement each other and allow for detailed study of the ISM properties. We propose to observe the z=1.4 radio loud quasar 3c298 for which we already have IFS observations. This quasar has been well studied over a broad range of wavelengths, allowing for a unique multi-frequency study of its host galaxy. The combined observations will explore the interaction between radio jets and molecular outflows, probe the interstellar medium and explore cold molecular gas dynamics and depletion time scales, CO excitation mechanisms, and determine dust, molecular gas, and stellar masses. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-03-02T21:49:34.000 |
| 3300 | 2017.1.01568.S | 8 | The structure of molecular gas in the metal-rich environment of a Super Luminous Supernova | Super luminous Supernovae (SLSNe) are a recently identified class of highly bright supernovae, with peak magnitudes about 100 times brighter than typical core-collapse supernovae. To date the physical nature of the energy source for these extremely bright events remains speculative. Massive star formation in dense environments seems to be the most likely primary condition for the formation of SLSNe. We propose to target a massive and fairly close SLSN host galaxy, the best available candidate, for CO(J=1-0) emission line observations to characterize for the first time the structure of molecular gas in the close environment of a SLSN. These observations will allow us to detect any features distinguishing the SLSN environment, to determine the mass of the molecular gas in the close environment of the SLSN, and to obtain the star formation efficiency and key information on the stage of the gas-to-star transition process that the host is in. In addition, we will be able to compare the structure of the molecular gas with that of the atomic gas in the SLSN environment as we have been granted observation time for high resolution mapping of the HI 21 cm emission line for the same target. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2019-02-15T14:01:17.000 |
| 3301 | 2012.1.00610.S | 0 | Probing fallback disks of nearby neutron stars | The birth and the evolution of neutron stars have strong impacts on their stellar environments as well as on the surrounding interstellar medium. For example, star formation is triggered, heavy elements are created and dust can be formed. The current knowledge about the neutron star evolution is rather incomplete. A complicating factor is the diversity of neutron stars. Several new neutron star populations have been discovered in recent years that cannot be explained within the standard pulsar model of a rotating dipole. One hypothesis that helps to understand the different neutron star populations, their links and the evolution of neutron stars in general, involves the so-called supernova fallback disks. These disks, predicted by current supernova models, have different masses composed of formerly ejected material that remained gravitationally bound. The disk masses and the initial birth properties of the neutron stars may govern the neutron star evolution. So far, fallback disks have been rather elusive. ALMA has the capabilities to probe these witnesses of neutron star evolution for the first time at submillimeter wavelengths in detail and with high angular resolution. Here, we propose to investigate two very promising fallback disk candidates which we recently identified in our Herschel PACS fallback disk survey. We need ALMA to confirm these candidates because the large PACS FWHM of around 11 arcsec cannot exclude potential source confusion. We also need ALMA to constrain the spectral energy distribution of the found candidates. These goals can be readily achieved in cycle 1 because the targets are expected to be bright at ALMA frequencies, and the current angular resolution is sufficient for these purposes. | Pulsars and neutron stars | Stars and stellar evolution | 2015-06-05T19:16:48.000 |
| 3302 | 2022.1.01756.S | 28 | From rotating envelopes to Keplerian disks: imaging the innermost accretion flows in high-mass star formation | Jets and outflows are commonly seen in both low-mass and high-mass star-forming regions, leading to a natural hypothesis that stars of all the masses form through disk accretion. However, even with decades of efforts in searching for disks in high-mass star-forming regions, it is still unclear if disks are a necessity, mostly due to the limited angular resolution and sensitivity of pre-ALMA (sub)mm interferometers. With an SMA survey of a large sample of massive dense cores within a remarkable giant molecular cloud, a unique sample of ~1000 au rotating (and also infalling) envelopes around high-mass protostars is derived, and makes it promising for the ALMA detection of Keplerian disks on ~100 au scales. We thus propose for ALMA observations of the sample, aimed at detecting genuine disks or spiral and/or filamentary accretion flows. Considering that the sample sources are of a single distance, cover a wide range of evolutionary stages, and have varying initial density structures, the uniform ALMA observations (in combination with the existing SMA data) would allow a deep insight into the detectability of disks and the nature of accretion flows in high-mass star formation. | High-mass star formation | ISM and star formation | 2024-11-23T19:03:00.000 |
| 3303 | 2015.1.00287.S | 36 | The Almost Forgotten Local Ultra Luminous Infrared Galaxy: IRAS 13120-5453 | Ultra Luminous Infrared Galaxies (ULIRGs) are rare in the local universe making this class of objects difficult to study in great detail. IRAS 13120-5453 is the second nearest (D = 137 Mpc) ULIRG in the universe after Arp 220; however, IRAS 13120-5453 does not have any published ground-based CO observations. We propose to observe IRAS 13120-5453 in several 12CO and 13CO transitions for some of the first high-resolution (0.3" = 190 pc) CO observations of this ULIRG. When compared to Arp 220, IRAS 13120-5453 has a similar far-infrared luminosity but optical images show that IRS 13120-5453 is much more compact with ordered structure in the form of spiral arms. Using the proposed observations, we will study the distribution and physical conditions of the molecular gas, comparing it to other local ULIRGs such as Arp 220 and Mrk 231. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-03-17T11:48:31.000 |
| 3304 | 2022.1.00321.S | 12 | Some like it hot: Dust temperature in the heart of a z>6 quasar | Quasars at z>6 have enormous dust reservoirs (>1e8 Msun) confined in their central ~kpc. This implies that 1) a substantial stellar population is already in place <1 Gyr after the Big Bang; 2) molecular gas dominates the mass budget in the core of quasar hosts; 3) both the quasar and star formation, in unknown ratios, contribute to the total IR luminosity; 4) a large fraction of quasars might be currently missing due to heavy dust obscuration. We propose to map the dust continuum in three bands (4-8-9), together with the [OI] 63um and H2O 321-312 line emission, in the extreme quasar PJ231-20 at z~6.6, which stands out due to its bright and compact dust continuum at 158um. Our pilot program will deliver matched resolution (0.2") maps of the system that will be used to gauge the dust temperature, optical depth, and emissivity index (and thus, the IR luminosity and dust mass), to sample the excitation conditions of the molecular gas, and to independently measure the SFR spatial distribution. This proposal will thus offer a unique insight on the interplay between dust, star formation and nuclear activity in one of the first massive galaxies in the Universe. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-05-05T08:43:23.000 |
| 3305 | 2019.1.01350.S | 6 | A 500-pc view of multi-phase ISM in a z = 8.312 galaxy: Benchmarking our understanding of galaxy formation | We propose 120 mas (~570 pc) imaging of [CII] 158um in a z=8.312 Lyman break galaxy MACS0416_Y1, which has recently been detected in [OIII] 88um, [CII] 158um and 850-um dust continuum in our Cycle 4 and 5 programs. MACS0416_Y1 has three individual clumps of young stars, and the [OIII], [CII], and dust emission apparently traces the stellar distribution. So, one of naive questions is why the multi-phase ISM traced by [OIII], [CII], and dust are co-spatial with the UV continuum on a few kpc scale, even though the UV continuum is fairly blue. A possible explanation is patchy/porous geometry of ionized gas, PDRs, and dusty molecular clouds at sub-kpc scales, which are all suggested by state-the-art hydrodynamic simulations of galaxy formation. Our A-graded Cycle 6 program is going to reveal the 90-mas [OIII] and dust images to map possible giant HII regions/supernova bubbles and dusty molecular associations. In Cycle 7, we will add longer baselines at Band 5 to spatially resolve the [CII] emission, allowing us to benchmark our understanding of galaxy formation by depicting multi-phase ISM distributions. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2022-08-26T16:53:44.000 |
| 3306 | 2016.1.01093.S | 4 | Resolved Dynamics of a Lensed Submillimeter Galaxy with [CII] Emission to <100 pc at z~3 | We propose to observe the [CII] 157.7 um line and the 700 um continuum at a spatial resolution of 50 mas and a velocity resolution of 20 km/s in a lensed submillimeter galaxy (SMG) at z=3.042, SDP.81. This galaxy is highly gravitationally lensed with the magnification factor of ~20. Therefore, the effective resolution reaches ~100 pc at z=3.042, which corresponds to the scale of large giant molecular clouds (GMCs). This is the highest-resolution observation of [CII] in high-z SMGs to date. Using the data, we will investigate whether or not the star formation mode of each molecular clump is sub- or super-Eddington. Moreover, combining with already acquired dust continuum data and CO data in 2014 as part of the ALMA Long Baseline Campaign, we will create the maps of [CII]/FIR continuum luminosity ratio and [CII]/CO line ratio, which are useful tools for probing the physical properties of the gas. Our observation is unprecedented in terms of resolving [CII] into the scale of GMCs at such a high-z. We are sure that the observation will get high legacy value for the high-z community. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-03-06T16:09:44.000 |
| 3307 | 2022.1.00640.S | 24 | Probing the Heart of a DUDE - The Central 200 AU of the Expanding Disk in the Carbon Star, V Hya | The carbon star V Hya is experiencing heavy mass loss as it undergoes the transition from an AGB star to a bipolar planetary nebula, and is possibly the earliest object known in this brief phase, which is so short that few nearby stars are likely to be caught in the act. STIS/HST data show a high-velocity bulleted jet outflow from the star, likely driven by an accretion disk around a close binary companion in an eccentric orbit. Such an outflow requires a source of angular momentum and magnetic fields, however, ALMA observations with ~0.5 arcsec (200 au) resolution, although resulting in several important discoveries in this remarkable object, have not uncovered any signature of rotation, perhaps because the rotating region is unresolved. We therefore propose to map 12CO(3-2) emission from the V Hya's central disk with 0.05 arcsec resolution. We will also observe CI (and other diagnostic species) to probe and model the chemistry of the central disk in V Hya, which is very different from the extended DUDE, likely due to the presence of UV. Our study will contribute to a broader understanding of several sub-classes of evolved stars which have binary companions in eccentric orbits. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2024-04-01T16:44:39.000 |
| 3308 | 2016.1.01063.S | 2 | Studying star formation via the [OI] 63 micron line within a billion years of the Big Bang | We propose ALMA observations of the [OI] 63 micron line in three z > 6 QSOs with existing [CII] 158 micron detections. Due to its brightness [CII] is now readily exploited for studies of early galaxies. The [OI] line, which is similarly luminous, has seen little use, primarily due to its short wavelength requiring a space based facility like Herschel for observations in lower-z and nearby sources. ALMA, however, with access to the short submillimeter telluric windows combined with its exquisite sensitivity has the capabilities to utilize this line for studies of z > 4.2 galaxies. Our proposed observations will demonstrate this capability by studying the [OI] line in three z>6 QSOs, where the line is observable in Band-9. We will characterize gas densities and far-UV radiation fields, constrain the gas heating and cooling budget, and investigate the cause of the observed variation in [OI]/FIR and [CII]/FIR ratios in distant galaxies. This pioneering work, completed in 3.8 hours, will let us place these early systems--forming stars within a billion years of the Big Bang--in context with lower redshift sources, improving our understanding of galaxy formation and evolution. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-04-06T23:30:36.000 |
| 3309 | 2018.1.00697.S | 176 | Do spiral-arm clouds fragment dynamically or gravitationally? | Most new stars in spiral galaxies form in the spiral-arms, however, the mechanisms that control star formation in these regions remain elusive. High-resolution studies of nearby galaxies imply that local processes that operate in the dense gas play a crucial role. These processes cannot be studied in external galaxies due to the lack of resolution; instead, we must gain insight by studying the analogs of spiral-arm clouds in Milky Way. Indeed, recent works have identified such analogs, but so far, their internal structure and physics are unknown. We will take a step forward by determining whether spiral-arm gas fragments gravitationally or dynamically, and at which scales these modes operate. We will determine the kinematics of a ~150 pc long section of the most prominent known spiral-arm cloud, so-called Nessie, covering three orders of magnitudes in size-scales. This will be done with ACA stand-alone observations of N2H+ and HNC emission in band 3. The observed velocity structure, gradients, and accelerations, together with our existing column density data, enable us to assess the fragmentation modes and to constrain the physical processes that control spiral-arm star formation. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-09-19T17:45:00.000 |
| 3310 | 2012.1.00775.S | 21 | Characterizing the [CII] 158um emission line in typical, main sequence-selected disk galaxies at z=1.8 | We propose to measure the [CII]158um luminosity of 11 normal, disk-like galaxies at z=1.7-1.9. All our targets have accurate spectroscopic redshifts, Herschel-derived IR bolometric luminosities, and stellar masses derived from multicolor imaging in GOODS-South, and have thus been selected for being securely inside the star forming 'main sequence' with specific SFRs close to the mode of all galaxies at their redshifts. No similar normal galaxy has been observed in [CII] so far at high-z, as observations have targeted hyperluminous systems. We will establish for the first time the typical LIR/L[CII] ratio for a sample of more representative z~2 galaxies. We will investigate how this ratio depends on the physical properties of the sample (stellar mass, age, morphology, reddening). Combining the 450um and 850um imaging from ALMA with our Herschel and Spitzer measurements we will derive robust estimates for their dust masses and temperatures by fitting their spectral energy distributions, and hence gas masses via metallicity, allowing us also to explore the dependence of the [CII] luminosity on these crucial quantities. By performing these measurements on z=2 samples of galaxies that are nowadays reasonably well understood in terms of their physical components, at least globally, and with likely similar specific SFRs and gas fractions to higher redshift systems, we will pave the way for defining future explorations of typical galaxies at much higher redshifts through [CII] observations. Studying a small sample of galaxies, as proposed here, is critical to obtain a first measurement of the scatter in properties in this baseline experiment. | Galaxy structure & evolution | Galaxy evolution | 2016-08-09T11:17:00.000 |
| 3311 | 2015.1.00956.S | 271 | How Does Cloud-Scale Physics Drive Galaxy Evolution? | A key goal in galaxy studies is to link the evolution of entire galaxies (many kpc scales) to the physics of feedback and star formation on the scale of an individual star-forming region (~50 pc). ALMA offers the first chance to take a systematic approach to this problem by imaging molecular gas across large parts of galaxies with full fidelity, sensitivity to individual clouds, and resolution matched to the scale of individual star-forming units. We propose to apply this revolutionary capability to image the active part of a representative sample of 8 high mass 'main sequence' galaxies, capturing a huge physical area (~800 kpc^2) and a diverse set of dynamical environments (e.g., bars, arms rings). This survey represents the natural next order-of-magnitude leap from previous low resolution surveys and individual high resolution case studies. We will use it to measure how: (1) small scale gas properties drive star formation on large scales, (2) gas cycles between different phases of the star forming process, (3) feedback and gravity balance over a large range of scales, and (4) the distribution and structure of the molecular ISM depend on galactic environment. | Spiral galaxies, Surveys of galaxies | Local Universe | 2017-05-20T18:28:25.000 |
| 3312 | 2024.1.01166.S | 0 | Probing Large Dust Particles in the Great Comet C/2023 A3 | Comets are the least thermally altered objects, preserving invaluable clues from the early protoplanetary disk (PPD). Cometary dust holds crucial information about the physical and chemical processes that shaped the formation and evolution of our Solar System. The newly offered Band 1 capability provides an unprecedented opportunity to probe dust properties from mm to cm sizes, which are crucial for grain growth in PPDs. In Cycle 11, the exceptionally bright Oort Cloud comet, C/2023 A3, will make a close approach to Earth, offering a once-in-a-decade opportunity to study the large dust grains of a pristine comet in detail. We aim to measure the thermal emission from mass-dominant large particles across four bands (1, 3, 6, 7) to obtain a comprehensive understanding of the grain size distribution and dust structure of A3. We also aim to compare our findings about comets with the multi-frequency observations of PPDs to enhance our understanding of the key mechanisms that drive grain growth processes. This study will not only provide insights into comet formation in our Solar System but also contribute to unraveling planet formation mechanisms around other stars. | Solar system - Comets | Solar system | 3000-01-01T00:00:00.000 |
| 3313 | 2016.1.01311.S | 17 | Quasar Feedback in the Early Universe: Lowest Eddington Ratio Quasar at z~6 | It has been found that quasars at z > 6 contain supermassive black holes (SMBHs) accreting mass at their maximal rates (Eddington ratio REdd ~ 1). However, it is suggested that their FIR emission is found to be unusually weak in comparison to their counterparts at lower redshifts, possibly due to a strong quasar feedback suppressing star formation in their host galaxies. Recently, we discovered a faint quasar at z ~ 6, IMS J2204+0112 with its REdd at only 0.04+-0.05. This finding suggests that there exist SMBHs with nominal accretion rates similar to lower redshift quasars, and that they may be a more general quasar population at z~6. Here, we propose to study the FIR property of IMS J2204+0112, by performing the submm continuum observation at ALMA bands 6 and 7. ALMA is currently the only facility that can trace the faint FIR flux of J2204+0112 (expected to be 130 uJy) and the two band observation can produce a reliable estimate of FIR luminosity. The proposed observation will teach us for the first time how the star formation in host galaxies is linked to the black hole growth at z~6 for a quasar with nominal accretion activity. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-05-09T00:59:29.000 |
| 3314 | 2015.1.00827.S | 4 | Kinematics and Chemistry of (the only?) Bonafide Massive Prestellar Core | Core accretion models of high-mass star formation require the existence of gravitationally bound massive starless cores, but robust observational examples of such objects have proven elusive. We have identified an excellent candidate for a massive prestellar core in the course of our extensive studies of GLIMPSE Extended Green Objects (EGOs): G11.92-0.61-MM2. Separated by ~7" from the nearby MM1 hot core, MM2 is a strong dust continuum source, but devoid of star formation indicators. In contrast to MM1, MM2 has no masers, no cm continuum, and, remarkably, no line emission in SMA (sub)mm observations covering ~24 GHz of bandwidth. The combined physical properties of MM2, inferred from its (sub)mm continuum emission, are extreme: T~17-19 K and M>30 Msun within a radius<1000 AU, corresponding to N(H2)>10^25 cm^-2 and n(H2)>10^9 cm^-3. We propose deep ALMA observations of MM2 in H2D+, the best tracer of extremely dense, depleted gas in low-mass starless cores. Our goals are to constrain the boundedness and stability of MM2, and to test the hypothesis that MM2 is, physically and chemically, a "scaled-up" analog of a low-mass prestellar core. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-06-14T14:52:26.000 |
| 3315 | 2016.1.01107.S | 2 | Hot (gas) physics with ALMA: SZ observation of a z=2 galaxy cluster | We propose ALMA and ACA 90 GHz observations of the z = 2 galaxy cluster Cl J1449+0856, to detect the Sunyaev-Zeldovich signature of its intracluster medium (ICM). The most distant X-ray detected bona fide cluster found so far, Cl J1449+0856 is observed at a pivotal epoch in the evolution of its ICM, when both warm and hot phases coexist and significant energy injection is expected to occur. This program aims at better constraining the total mass of the cluster as well as the pressure profile of the ICM in a poorly explored mass and redshift range. This observation will also probe the presence of significant anisotropy in the ICM, a distinct possibility given the nature of this structure. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2018-07-18T11:25:39.000 |
| 3316 | 2019.1.01003.S | 156 | Challenging the paradigm? The environment of the first supermassive black holes in the Universe | The current paradigm to explain the formation and early growth of the first supermassive black holes postulates that their seeds (and thus, the first quasars) reside in some of the most pronounced matter and galaxy overdensities in the early universe. However, despite monumental investments (hundreds of hours with 8-10m class telescopes), optical/NIR observations have so far failed to provide conclusive evidence in support of this scenario. Only very recently unambiguous evidence of galaxies that are associated with the immediate environment (<100 kpc) of z>6 quasars is appearing, thanks in particular to ALMA [CII] observations. Here we propose to circumvent the limitations of the small field of view of ALMA by capitalizing on a synergy with SCUBA sub-mm observations of quasar fields in which small-scale overdensities have been reported. If we confirm that a conspicuous fraction of the bright SCUBA-detected galaxies are indeed at the redshift of the quasars, we will have first robust evidence of the first massive large-scale overdensities in the universe. In case of a negative result, our observations will strongly shake the current paradigm of massive black hole formation. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2021-03-20T17:36:45.000 |
| 3317 | 2024.1.00317.S | 0 | Combining new and archival ALMA observations for dense gas and star formation studies in U/LIRGs | We aim to measure the dense gas mass fraction and star formation efficiency in a uniform sample of 16 nearby Ultra-Luminous and Luminous Infrared Galaxies. We will compare our observations with turbulent models of star formation. We propose to observe HCN (1-0) in 7 galaxies with <500 pc resolution. Our observations will add to existing archival HCN (1-0) data for a further 9 galaxies, as well as archival CO (1-0), CN (1-0), and radio continuum data for all 16 galaxies. With this dataset, we will: (1) compare variations in dense gas mass fraction and dense gas star formation efficiency on resolved scales with those previously observed on kiloparsec scales in normal spiral galaxies; (2) investigate any correlations between dense gas mass and star formation rate surface density; (3) compare the observed dense gas fraction with gravo-magneto-turbulent models that calculate the star-forming fraction of dense gas; (4) explore how dense gas traced by HCN compares to another dense gas tracer, CN, in a uniform sample of galaxies on resolved scales. We will test if any variations correlate for both tracers. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3318 | 2013.1.00832.S | 5 | A CO Study of An Exceptionally Cold Cloud in the LMC | We propose to use ALMA to image the molecular gas emission from an remarkably cold and quiescent dust cloud at the southern edge of the Large Magellanic Cloud (LMC). This cloud falls outside the area of the NANTEN CO survey and was detected as a decrement in dust temperature in the 4' resolution Planck map. More recent follow-up with the Mopra Telescope reveals strong CO(1-0) emission (T_b ~ 3 K at a physical resolution corresponding to 10 pc). The location of this cloud, near the region of greatest compression by ram pressure due to the LMC's space motion, and the lack of massive star formation activity suggest that it may have recently condensed from HI. We will make a complete map of the main body of the cloud, covering an area of 20 x 50 pc, in order to reveal the density and velocity structure down to a scale of <1 pc. Our main goal is to compare the density and velocity structure of the cloud with predictions from theory and observations of actively star-forming clouds. We will also assess the dynamical state of the clumps within the cloud, i.e. their balance of kinetic and gravitational energy, as a function of spatial scale. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2021-08-12T00:00:00.000 |
| 3319 | 2019.1.00027.S | 139 | Molecular line flux ratios and buried AGNs in merging ultraluminous infrared galaxies | Scrutinizing deeply buried AGNs in merging dust/gas-rich ultraluminous infrared galaxies (ULIRGs) is crucial to understand how supermassive black holes grow in mass in the universe, but has been hampered by large dust extinction. Observations at the almost dust-extinction-free (sub)millimeter wavelength can be a powerful tool, because an AGN and a starburst should produce different (sub)millimeter molecular rotational J-transition line flux ratios through different physical/chemical effects. We propose 0.1-0.2" resolution HCN and HCO+ J=4-3 and J=2-1 line observations of ULIRGs which show elevated millimeter HCN J=3-2 emission at the nuclei where putative luminous buried AGNs are expected to reside. We aim to distinguish, based on multiple J-transition HCN and HCO+ data, whether the elevated nuclear HCN emission is due to (1) HCN abundance enhancement by AGN radiation/mechanical effects and/or (2) simply higher HCN excitation by dense and warm nuclear molecular gas. If we confirm that the first mechanism is primarily responsible, the enhanced HCN emission will be an even more solid indicator of luminous buried AGNs in the nearby and distant ULIRG population. | Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2022-09-08T00:00:00.000 |
| 3320 | 2017.1.00261.S | 0 | Resolving the disk fed by filamentary streamers in the proto-O star W33A | We propose to follow-up our Cycle 1 (delivered in Cycle 2) observations to fully trace the 3D velocity field of the material accreting onto a newly forming O-star. Our target, W33A, a proto-O-star, is nearby (2.4 kpc) and well studied, already having a rare combination of high resolution observations at near-IR (Gemini-AO- 0.13") and mid-IR (VLTI-MIDI - 0.04") plus our Cycle 1 data (~0.3"). Our ALMA data show a spiral filament feeding material to the central region, where the velocity profile show signs of rotation, suggesting the O-star is forming via a disk. This `disk' appears disrupted by infalling streams (we find at one on 1000au scales - Maud et al. 2017 MNRAS 472 120), fragmentation due to gravitational instability, or interaction with companions. However, we have not yet resolved the disk scales <500au of the system to determine which is the case. Our 3D radiative transfer models (dust & gas) including infall from the outer rotating envelope onto a compact system best matches the binary scenario (disk radii <250au). ALMA will reveal the answer, as it is the only instrument that can zoom in and image the sub-100au scales, allowing us to test massive star formation theories. | Disks around high-mass stars | Disks and planet formation | 2019-03-09T15:53:09.000 |
| 3321 | 2017.1.01399.S | 97 | How does the large scale magnetic field affect the infall in prestellar cores? | Lupus I is a low-mass star-forming filament currently undergoing a star-forming event. Polarization measurements from optical polarimetry (Franco & Alves 2015) and dust polarization (Matthews et al. 2014) have revealed that the large scale magnetic field is oriented perpendicularly to the main filament axis and that the cloud is magnetically supported. The orientation of the prestellar cores, gravitationally bound objects which are expected to form stars, are found to be often oriented parallel or perpendicular to the magnetic field, suggesting an influence of the magnetic field on the formation and/or evolution of prestellar cores. We propose a detailed gas kinematics study of one class 0 object and eight prestellar cores: four oriented perpendicular and four parallel to the magnetic field, resolving the major axis of the prestellar core to differentiate between the infall motions along the minor and major core axis, and compare these infall motions with models of ambipolar diffusion. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-11-23T17:07:28.000 |
| 3322 | 2018.1.00341.S | 10 | Unveiling the formation scenario of born-again PNe through ALMA observations | Born-again planetary nebulae (PNe) are thought to be evolved objects that have experienced a very late thermal pulse (VLTP) when the central star was on the white dwarf track. The VLTP event produces an ejection of processed H-deficient material that interacts with the old PN. Optical and IR studies suggest that the evolution of the H-deficient material is fast with timescales of ~20-100 yr. Thus, these objects offers the possibility of studying the formation and evolution of dust and molecules in human timescales. We propose to study the spatio-kinematic properties of the youngest born-again PNe in which molecular emission has been detected but not resolved. Our observations will bring insights in the early formation of non-isotropic ejections in evolved stars and will constrain the current formation scenario of born-again PNe. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2022-10-26T14:42:43.000 |
| 3323 | 2013.1.00481.S | 11 | Resolving the Mysterious Broad-line Absorption Filaments in the Galactic Center | The most intriguing puzzle generated by the ALMA Cycle 0 observations of the "Brick" (G0.25+0.02) is the presence of broad-line absorption filaments seen only in the optically thick HCO+ (1-0) transition. These are new features of the Galactic Center -- never seen before ALMA pointed at the Brick, and we don't know what they are. The features are almost unbelievable -- unresolved (<1.7'') in the narrow dimension and 30 to 50'' long with absorption seen over 20 km/s. We propose a quick and simple experiment to test two theories for the origin of these filaments: (1) ram-pressure confined shocks or (2) magnetic confinement of ions. We will attempt to measure the true width of the filaments by observing at 3 times higher angular resolution. We will also observe the other bright ground-state ionic transition at these frequencies, N2H+ (1-0). It is possible that our observations will rule out both toy models! We are in uncharted territory, and desperately need the additional information these observations will provide to constrain our explanations of these amazing features. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-02-24T19:16:19.000 |
| 3324 | 2016.1.01119.S | 34 | Dense gas vs. star formation in NGC 7465 | Dense gas in galaxies is associated with star formation. The detailed study of dense molecular gas in galaxies thus provides an important test of the validity of the relationship between star formation rate (SFR) and HCN luminosity on different galactic scales - from whole galaxies to giant molecular clouds in their molecular gas rich centers. NGC 7465 is a luminous minor merger hosting an extraordinary starburst region with efficient star formation. A complex ISM is associated with the starburst. The molecular gas is associated with a polar, warped gaseous disk perpendicular to the stellar disk. The HCN/CO line ratio however is low, suggesting that the dense molecular gas is not involved in the efficient starburst. We plan to image the dense molecular gas in NGC 7465 and compare its properties to the larger scale molecular gas through HCN, HCO+ and 12CO 1-0 observations. We will chart the role of the dense gas as a tracer of the physical state and dynamics of the nuclear region ISM: Is the dense gas associated with the warped gaseous polar disk or predominantly with the AGN? Will the HCN/HCO+ ratio change to reflect the 1) AGN environment and/or 2) the star forming environment? | Merging and interacting galaxies | Galaxy evolution | 2018-01-06T04:43:23.000 |
| 3325 | 2015.1.01020.S | 10 | Impact of magnetic field on high-mass star formation: the case study of the W43-MM1 pre/proto-stellar cluster | Despite its omnipresence in the ISM and its now quasi-systematic integration in star-formation models, observational constraints of the magnetic field in high-mass star-forming regions are rare. The W43-MM1 ridge, being extreme in terms of cloud concentration and high-mass star formation is a case study to be confronted with star-formation models. Within the W43-MM1 ridge, we propose to image the magnetic field of 10 massive dense cores (MDCs) in pre/proto-stellar evolutionary stage to: - Calculate the mass-to-magnetic flux ratio of the 10 MDCs and compare to predictions of magnetically regulated core-collapse - Compare fragmentation level with respect to prediction from MHD controlled model - Examine the orientation of the magnetic field with respect to the outflows orientation (6 of the 10 MDCs of our sample drive outflows) - Seek for an eventual alignment of the magnetic field with infalling stream motions down to the protostellar typical scale of ~4000 AU | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2017-06-30T11:38:41.000 |
| 3326 | 2017.1.00501.S | 120 | GUAPOS: G31.41+0.31 Unbiased ALMA sPectral Observational Survey | We propose to carry out an unbiased spectral line survey in Band 3 of the hot molecular core (HMC) G31.41+0.31 (G31). This is one of the most chemically rich HMCs in the Galaxy and an excellent target to search for heavy complex organic molecules (COMs), especially prebiotic ones. Band 3 is preferred because with respect to higher frequencies line blending is less severe and the dust emission is optically thinner. The main driver of the project is the identification of species never detected before outside the Galactic Center and of new species not yet detected in star-forming regions. We will concentrate on the study of: i) heavy COMs (especially with >10 atoms); ii) N-bearing COMs: like amino acetonitrile, precursor of glycine; iii) deuterated species: to obtain a more complete census of COMs in HMCs; iv) P-bearing and S-bearing species; and v) isotopologues: to understand the processes governing fractionation. The proper identification of species will allow us to derive important physical parameters, such as abundances, needed to constrain the chemical models and to investigate the relative contribution of surface-chemistry and gas-phase chemistry on the formation of COMs. | Astrochemistry | ISM and star formation | 2019-03-26T16:11:11.000 |
| 3327 | 2022.1.00825.S | 85 | Gas and Ice: Inheritance or Reset in Taurus planet forming disks? | The abundance and distribution of volatiles in protoplanetary disks is crucial to our understanding of the formation of planets and their habitability. Yet, we still do not known how much of the infalling icy material from the natal cloud makes it unscathed into the shielded disk midplane, and how much of it is reset to its atomic constituents in the gas phase. The gaseous C/H abundance in disks has previously been shown to probe the amount of ices available in the midplane. The recent discovery of Class II sources with late infall facilitates the study of the role of infall on the gaseous and icy chemical inventory in protoplanetary disks. We propose to observe the gaseous carbon abundance tracer [CI] at 492.161 GHz and the C/O ratio tracer CCH in Band 6 in a sample of thirteen protoplanetary disk in the Taurus star forming region, limiting any biases of different starting conditions. Six of these sources have clear signs of infall. By comparing sources with and without infall, at different stages of their evolution, we will trace the level of molecular reset upon infall and the effect that reset has on the amount of ices that are frozen out in disks as a function of time. | Solar system - Planetary surfaces | Solar system | 2024-09-21T12:44:16.000 |
| 3328 | 2013.1.00387.S | 5 | Testing the Anisotropy of Turbulence in Protoplanetary Disks | Turbulence is a key actor for evolution of protoplanetary disks and formation of planets. Although substantial progress has been made in understanding turbulence and its properties via 3D MHD simulations, these predictions still has to be observationally constrained. We propose here to test one of the predictions of MHD models, the amount of anisotropy of the turbulence by observations of two disks, one face-on (TW Hya), one edge-on (Flying Saucer). The unique combination of high spatial and spectral resolving power and sensitivity of the Cycle 2 ALMA will allow us to image simultaneously CS 5-4, CN 2-1 and 12CO J=2-1, and characterize distributions of turbulent velocities through these disks. | Disks around low-mass stars | Disks and planet formation | 2016-08-07T11:05:20.000 |
| 3329 | 2021.1.00486.S | 12 | What is Carving the Gaps in Young, Embedded Disks? | Protoplanetary disks with ages of 1-5 Myr are often found with large holes in their centers. These "transition" disks are hypothesized to be carved out by planets hiding in the inner regions of the disk, and indeed some evidence has been found for planets hiding in such gaps. Recent observations of young (<0.5 Myr) embedded disks have now found several cases of embedded protostars that have a large cavities in their disk as well. Existing observations, however, are insufficient to determine whether these holes are cleared by stellar (or brown dwarf) companions or protoplanets. Here we propose to observe a sample of 8 Class 0/I "transition disks" in continuum and gas lines to determine the clearing mechanism. As the properties of the gas cavity relative to the dust cavity have the power to infer the masses of the bodies carving these features, our proposed observations will have the power to distinguish between each scenario. If planets could be shown to be carving these holes, it would place very strong constraints on the timescales on which planet formation begins. | Low-mass star formation | ISM and star formation | 2023-03-25T22:17:57.000 |
| 3330 | 2016.1.00725.S | 29 | A Hunt for Massive Starless Cores II. Follow-Up of Most Promising Candidates to Measure Dynamics and Deuteration | We are searching for massive starless cores to test massive star formation theories. We have several promising candidates identified from a snapshot survey of N2D+(3-2) emission carried out with ALMA in Cycle 2 towards 32 IRDC clumps. Here we propose to follow up several of the most promising sources with higher sensitivity N2D+(3-2) observations to measure core dynamics and also search for outflow activity. We will also observe N2H+(3-2) from the cores in order to measure the degree of deuteration of this species, which can constrain chemodynamical models and simulations that further test core dynamics. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-04-10T21:11:20.000 |
| 3331 | 2013.1.00058.S | 30 | Unveiling molecular gas in local galaxies from the Herschel-ATLAS | We wish to use ALMA to obtain the first spatially resolved and sensitive imaging of the [CI](1-0) and 12CO(1-0) lines in a sample of nearby (z~0.07) Herschel Astrophysical TeraHertz Large Area Survey (H-ATLAS) galaxies detected by their dust content, in order to trace their molecular hydrogen content. A key problem in astronomy is how to reliably measure the amount of H2 in galaxies since a significant proportion may be missed when observed via the traditional tracer, the CO molecule. With the new ALMA Band 8 receivers we will be able to carry out the first observations of the[CI](1-0) fine structure line of atomic carbon in a sample of galaxies in the nearby (z~0.07) Universe and, together with the standard tracer CO(1-0), will be able to address: a) whether molecular gas in nearby galaxies is well-traced by CO or whether [CI] is a better tracer of the bulk of the H2, b) how the molecular gas mass and corresponding gas-to-dust ratio in nearby galaxies vary with properties such as Hubble type, metallicity, SFE, dust properties and c) it will contribute to an innovative method to calibrate dust as a tracer of gas and obtain molecular gas masses for 30,000 galaxies out to z~0.5. | Surveys of galaxies | Galaxy evolution | 2016-03-27T14:46:20.000 |
| 3332 | 2016.1.01347.S | 317 | Extremely high velocity jets from massive YSOs | Simulations of massive star formation show that outflows are fundamental for the formation of massive stars as they enable accretion to proceed up to stellar masses as large as 140 Msun. In low-mass star formation, models predict disk-mediated accretion and ejection of a collimated jet accelerated by the magnetic field. The jet produces a thin outflow which clears the surrounding dense gas and produces density-enhanced cavity walls. This is well supported by observations which show a defined kinematical pattern in jet/outflow systems: a collimated jet at extremely high-velocity surrounded by low-velocity cavity walls. Collimated jets have never been seen in YSOs with L>10^4 Lsun although models predict their presence up to masses of 30-35 Msun. We propose to observe a complete sample of massive YSOs from the ATLASGAL Top100 sample to search for jet/outflow-cavity structures and establish whether massive outflows are also driven by collimated jets. The sources have extremely high-velocity wings, highly indicative of jets, and luminosities L>10^5 Lsun, correponding to ZAMS stars of 20-40 Msun. They are ideal to test model predictions and verify whether jets exist in massive YSOs. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2019-01-26T00:00:00.000 |
| 3333 | 2017.1.00773.S | 76 | Snapshots of 6 Ultra-Red z > 6 SCUBA-2 sources from the JINGLE survey | The Herschel ultra-red dropouts (sources which are detected at 850 microns, but not detected in Herschel-SPIRE) are a poorly studied population of SMGs. Their SEDs appear to peak around 850 microns, suggesting that they lie at z >> 4, well beyond that of most Herschel selected sources. Only 1 dropout source has a confirmed redshift so far, at z = 5.6, but with the advent of large legacy surveys at 850 microns, many more are expected to be discovered. In JINGLE, a ~5.5 sq degree legacy survey of local galaxies at 850 and 450 microns, we have serendipitously detected 6 bright (F850 > 10mJy) dropout sources in the GAMA12 and GAMA15 fields. Using a photo-z fit, we constrain the redshifts of these sources to be z ~> 6. Thus, these sources could represent the highest redshift SMGs found to date. Here we propose to use ALMA to constrain the position of these sources to within 1 arcsecond, and simultaneously obtain band 4 continuum imaging, which will reduce the uncertainty in the redshift by ~ 20x. These observations pave the way for a future program to undertake a dedicated line search to confirm the redshift of these sources. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-02-01T10:04:26.000 |
| 3334 | 2013.1.01282.S | 3 | Polarimetric Observation of Centaurus A: Poloidally-dominated magnetic field vs. Toraoidally-dominated magnetic field in the Innermost Jet | We propose band-7 polarimetric observation of the nearby radio galaxy Centaurus A. The polarimetric observation is the unique tool to investigate the magnetic field structure of the extragalactic jets. In particular, the magnetic field property in the innermost jet is a key ingredient to understand the jet formation and acceleration. However, the innermost magnetic field structure has been hardly explored so far. The major problem is that polarized emission cannot be detected in parsec scale because of strong depolarization effect at centimeter wavelengths. Mm/submm observation is essential to avoid such a depolarization and to investigate the polarized emission from the innermost jet. Our ALMA band-7 observation will firstly unveil the magnetic field structure in the innermost jet of Centaurus A. From this observation, we will distinguish whether the magnetic field is poloidally-dominated or toroidally-dominated. This is highly important to understand the role of magnetic field for the jet production since the jet production state is expected to be dependent on the magnetic field morphology based on the recent general relativistic magnetohydrodynamical simulations. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-12-15T00:00:00.000 |
| 3335 | 2016.1.00308.S | 30 | Searching for the first extragalactic hot molecular cores | We propose to search for the first extragalactic hot molecular cores toward three prominent high-mass star-forming cores in the N159 star-forming region in the LMC. Hot cores constitute a very important stage of the stellar development, when the star already emits copious IR radiation, thereby heating up its environment, but before he destroys its molecular cradle by ionizing it with UV photons. Pragmatically, hot cores, by virtue of their high temperatures and densities, are also strong emitters of many molecular lines, which makes them relatively easily observable. No extragalactic hot core has been found so far, and detecting them in the LMC will be particularly rewarding, as it allows to probe how high-mass stars form in low-metallicity galaxies, which are representative of the environment at the peak of star formation in the universe. It is known that the chemistry of the ISM in metal poor galaxies is different, but does this extend to the densest, most shielded regions? How does this affect the formation of organic molecules, which may play a role in the emergence of life? | Galaxy chemistry, Dwarf/metal-poor galaxies | Galaxy evolution | 2017-10-26T23:48:45.000 |
| 3336 | 2016.1.00583.S | 29 | Non accreting proto-planetary discs: a new evolutionary class? | The aim of this proposal is to observe three unusual protoplanetary discs in the young (2-3 Myr), nearby (~160 pc) Chameleon I region: they have a large IR excess but do not show any detectable accretion, contrary to the conventional picture of disc evolution in which accretion and IR excess disappear at the same time as the disc is dissipated. The targets have a measured sub-mm continuum but no gas detection in an ALMA Cycle 2 survey, opening the question whether they are gas depleted and transitioning to the discless phase. We propose a sensitive search of gas emission lines (CO isotopologues) to establish their gas content, allowing us to assess whether they are young, optically thick debris discs (i.e., little or no gas left over), gas rich discs with inefficient angular momentum transport, or low mass discs that are surprisingly resilient to photo-evaporation. In any case, we would gain insight on a class of object that has received little attention up to now. ALMA is the only instrument sensitive enough to perform such a search. | Disks around low-mass stars | Disks and planet formation | 2018-12-15T14:49:43.000 |
| 3337 | 2023.1.01726.T | 0 | Determining the cooling timescale in a shadowed protoplanetary disk | The planetary systems detected so far show a great diversity in their architectures, which may originate from the variety of initial conditions for their formation in protoplanetary disks. Disks evolve through a variety of mechanisms, such as planet formation and (magneto-)hydrodynamical instabilities. Theoretical models of these processes and interpretation of disk observations however require strong assumptions to be made on fundamental and unknown disk properties, such as the gas mass and the temperature structure. In this proposal, we aim to observationally measure the cooling timescale of a shadowed protoplanetary disk by obtaining nearly contemporaneous observations of a shadowed disk with SPHERE and ALMA. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2025-08-09T19:21:11.000 |
| 3338 | 2024.1.00885.S | 0 | ALMA NH2D Imaging in Exceptional Comet C/2023 A3: Coordinated Studies with VLA and NASA IRTF | We propose ALMA imaging of NH2D and CH3OH in exceptional Oort cloud Comet C/2023 A3. Comet A3 will be incredibly active and bright during Cycle 11, potentially representing the brightest comet of the decade and affording unique opportunities to address pressing questions in cometary science. This study will (1) Measure the D/H ratio in NH3 in an Oort cloud comet for the first time through ALMA imaging of NH2D and contemporaneous observations of NH3 with VLA and NASA IRTF; (2) Spatially resolve NH2D formation in the coma, revealing whether it is produced from direct nucleus release or from thermal degradation of ammonium salts or other refractories in the coma, thereby testing the ammonium salt hypothesis for the nitrogen deficiency in comets. Fully recovering the extended NH2D emission requires simultaneous 12m and ACA observations. Simultaneous measures of multiple CH3OH transitions at high resolution will resolve coma gas kinematics and temperature. This study can only be carried out with the high sensitivity and angular resolution of ALMA, and only in an exceptionally bright comet such as C/2023 A3. | Solar system - Comets | Solar system | 2025-10-18T13:24:34.000 |
| 3339 | 2018.1.01716.S | 40 | Thinning the rings: 3 mm observations of the multigapped disk of HD 169142 | The recent discovery of multiple rings and gaps in protoplanetary disks has sparked a lot of interest since these substructures could work as dust traps, accumulating grains and enhancing their growth. However, several observations indicate that disk substructures are optically thick up to ~2 mm, which hinders our ability to study their role in the dust evolution process. We propose to observe the multigapped disk of HD 169142 at 3 mm with very high angular resolution, unveiling the optically thin emission of the disk with an extreme degree of detail. These data, together with other ALMA and VLA observations, will provide the most accurate resolved measurements of the spectral index in HD 169142 so far. We will test different gap formation mechanisms in the system and explore the possible dust trapping of large grains in disk substructures. Given the spectacular double ring morphology of HD 169142 and its variety of interesting features, this system is among the best laboratories to test our understanding of grain growth and planet formation. | Disks around low-mass stars | Disks and planet formation | 2020-12-26T19:53:30.000 |
| 3340 | 2016.1.01484.S | 4 | Resolving De-polarization and Magnetic Field Convergence Zones in W51 | Our ALMA cycle-2 polarization data (~0.27 resolution) improved upon the SMA (~ 0.7 resolution) by about a factor of 7 in area. The data are revealing striking new details in the high-mass star-forming region W51 e2/e8: (1) B-field morphologies in several individual cores are clearly resolved, suggesting a scenario where local collapse likely happens, but cores themselves are also pulled to a more massive global center, and several zones of seemingly converging field lines are found; (2) Polarization is found to be systematically variable, with de-polarization zones that can now be identified with field convergence zones. We propose 0.1 resolution polarization observations in band 6 with the goal of (1) mapping the detailed field morphologies in convergence / de-polarization zones to understand their physical origin and (2) quantitatively analysing the role of the magnetic field vs gravity in e2/e8. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-11-14T13:06:20.000 |
| 3341 | 2016.1.00380.S | 114 | Characterizing Molecular-Cloud-Scale Chemistry in the Large Magellanic Cloud | The Large Magellanic Cloud (LMC) is the nearest external galaxy, whose metallicity is known to be lower by factor of 2 than in our Galaxy. In our previous study, we observed 7 molecular clouds in the LMC with the Mopra 22 m telescope and found the molecular-cloud scale (~10 pc) chemical composition characteristic to the LMC. To explore its origin, we resolve the cores (~0.5 pc) and characterize their chemical compositions. According to our Mopra observations, CCH is found to be abundant in the LMC clouds than that of our Galaxy, while CH3OH is less abundant in the LMC. This is interpreted as the effect of extended photodissociation regions (PDRs) due to the lower abundance of dust grains. In addition, abundances of sulfur-bearing molecules, CS and SO, slightly differ from cloud to cloud, probably reflecting the evolutionary stages of each cloud. We examine these characteristic features at a high angular resolution. | Magellanic Clouds | Local Universe | 2018-02-10T04:54:02.000 |
| 3342 | 2015.1.01120.S | 12 | The role of cosmic rays regulating star formation in AGN | The giant radio-galaxy 3C326N is perhaps one of the best examples of negative AGN feedback. With 2e9 Msun of molecular gas, its SFR is only <0.07 Msun/yr, 20 times lower than what is expected from the Kennicutt law. Why is star formation suppressed? Outflows and turbulence are possible culprits, but the role of cosmic rays (CR) has been neglected, because we lack constraints on the CR flux. However, they could play a major role by heating the molecular gas, controlling its ionization state, and driving outflows, which could regulate star formation. To test those hypothesis, we propose to map with ALMA the CO(1-0) and [CI]609um lines in 3C326N. Our models show that the CO/[CI] line ratio is a sensitive diagnostic of the CR ionization rate. We will search for a CR-driven outflow by looking at spatial variations of the CO/[CI] ratio. If CRs turn out to be an important source of ionization and heating of the H2 gas, they could provide a universal, and so far ignored, mechanism for AGN feedback. The AGN physics explored here will greatly enhance our understanding of why 3C326N, and massive early-type galaxies in general, have large masses of molecular gas but yet weak star formation. | Merging and interacting galaxies | Galaxy evolution | 2018-02-21T16:27:41.000 |
| 3343 | 2018.1.01427.S | 8 | A CO and dust emission search for a counterpart galaxy associating with a z=3.3 DLA found in a galaxy spectrum | ALMA is revolutionizing the way of searching for galaxies hosting Damped Lyman Alpha sytems (DLAs). CO, [CII] and dust emission observations with ALMA is becoming the most efficient tool for identifying the DLA host galaxies from low redshift to high redshift. Here we propose Band 3 observations aiming at detecting CO(4-3) and dust continuum emission from a counterpart galaxy of a DLA at z=3.3 discovered in a background galaxy spectrum. Unlike usual DLAs found in QSO spectra, this new population of DLAs, "galDLA", must have a >1 kpc^2 area covering the extended luminous part of the background galaxy. Thus, galDLAs may have different properties compared to usual QSO-DLAs although there are only two galDLAs known so far. The target galDLA is associating with a large-scale galaxy overdensity, which is another remarkable property making it quite unique. The proposed observations also enable us to observe [CI](1-0) emission from the background galaxy at z=3.6 and CO(4-3) lines from two galaxies, which are found at 140--200 kpc away but at the same redshift as the galDLA, in the field-of-view. | Lyman Break Galaxies (LBG), Damped Lyman Alpha (DLA) systems | Galaxy evolution | 2019-12-10T20:06:16.000 |
| 3344 | 2013.1.00615.S | 3 | Does the magnetic field regulate the collapse in the massive core G31.41+0.31? | The most clear example up to date of an hourglass-shaped magnetic field morphology in the high-mass regime is that of the very massive (500 Msun) and luminous (2e5 Lsun) hot molecular core G31.41+0.31. To elucidate whether the magnetic field plays an important role in the collapse of G31.41+0.41, we propose to observe with ALMA in Band 6 at the highest angular resolution, 0.18arcsec, which will provide an unprecedented image of the magnetic field morphology and kinematics down to about 1000 AU scales. | High-mass star formation | ISM and star formation | 2016-10-26T01:12:45.000 |
| 3345 | 2018.1.00738.S | 241 | An Unbiased Survey of Dust Emission in Isolated Interacting Dwarf Galaxy Pairs | Interactions between pairs of dwarf galaxies are expected to be the most numerous galaxy-galaxy interactions in the Universe. However, little is known about the way interactions affect the ISM and stellar mass build-up of dwarf galaxies, compared to what is known for massive galaxies. We propose 7m array dust continuum observations of a sample of 10 interacting dwarf pairs from the TiNy Titans Survey. These observations will be used to measure dust masses for the interacting pairs and to infer molecular gas masses. With the resulting molecular mass estimates and our in-hand star formation rates and HI masses we will determine if dwarf galaxy mergers can enhance the star formation efficiency and the molecular gas fraction, as has been seen for massive galaxy mergers. This will significantly improve our understanding of the impact of dynamical interactions on the evolution of dwarf galaxies. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2020-01-04T20:48:41.000 |
| 3346 | 2023.1.00264.S | 0 | Systematic search of H2O emission in quasar host galaxies at z>6 | Quasars beyond redshift z~6 are the most luminous and active sources when the Universe was less than 1 Gyr old. Their extreme luminosities and the intense star formation in their host galaxies make these objects ideal laboratories to characterize the interstellar medium (ISM) at the dawn of cosmic time. While traditional tracers of the cold (T<100 K) ISM, such as [CII] and CO, have now been reported in about 50 quasars at z>6, very little is known about the warm, dense phase of the molecular medium that is associated with shocks and outflows. This phase can be studied via water vapor emission, but so far only sporadic detections have been reported at z>6. Here we propose to systematically sample a suite of key diagnostic water transitions (along with CO and OH+ lines) spanning a wide range of energies in four IR-bright quasars at z>6 (for a total of 26 emission lines). By doubling the existing sample of high-z quasars with multiple H2O detections, this program will enable the first quantitative and statistical analysis of the H2O emission in z>6 quasars and will provide us with a temperature measurement of the warm dust component for the first time in galaxies at cosmic dawn. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-04-30T11:18:35.000 |
| 3347 | 2015.1.00224.S | 27 | Imaging a site of planet formation in the GG Tau A system | Using ALMA, we have started to investigate the physics and dynamics of the environment of young multiple stars in order to understand how such systems can form planets, either in circumstellar of circumbinary orbits. Our first results deal with the triple TTauri system GG Tau A. Thanks to Band 9 observations of ALMA at 0.3'' resolution, we were able to image CO gas flowing from the outer ring through the inner cavity onto the inner disks. The observations also reveal the existence of a puzzling hot spot at the outer edge of the ring which may indicate the presence of an embedded accreting proto-planet. An unresolved gap seen in the new Band 7 13CO J=3-2 map at 0.4'' strongly reinforces this explanation. We propose to use the almost full array sensitivity of ALMA to image the gap and the ring in 13CO, C18O, CN J=3-2 and in continuum with an angular resolution of 0.1'' and a spectral resolution of 0.2 km/s. The images will be directly compared to Hydrodynamical simulations performed using the code Genesis. Resolving the gap size will also allow an estimate the mass of the embedded object. | Exo-planets | Disks and planet formation | 2018-04-10T13:45:19.000 |
| 3348 | 2017.1.00376.S | 16 | Planetary Nebulae genesis: emerging HII regions around post-AGB stars. | Based on the exciting results from our pilot search for radio recombination lines (RRLs) in a small sample of pPNe, we propose to map with ALMA (0.03-0.08"-resolution) the emerging ionized cores of three representative objects. RRLs at mm-wavelengths are unique probes of the dense inner and heavily obscured regions of pPNe, where the yet unknown agents for PN-shaping operate. Typically, mm-RRLs have intensities and line-to-continuum flux ratios larger than cm-RRLs and, thus, are more easily detectable. Most importantly, cm-RRLs trace of the relatively tenuous environments of evolved and well developed PNe but NOT the dense inner winds of pPNe. The proposed observations will certainly produce significant new insights into the physical conditions, structure, and dynamics of the, up to date inscrutable, inner regions of pPNe. This is a resubmission of proposal 2016.1.00161.S, which was included in the Cycle 4 observing queue with priority C. This program has been partially observed (CRL618 at 1mm with ~0.2arcsec) but unlikely to be finished in clycle 4. Should this project be finished in cycle 4, this proposal will be withdrawn. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-12-20T18:29:27.000 |
| 3349 | 2016.1.00497.S | 2 | Probing particle trapping in transition disks via dust polarization | Observational constraints on the size of grains embedded in a protoplanetary disk are absolutely fundamental to understand the planet formation process. Self-scattering by large dust grains having a high enough albedo can account for the polarized emission at mm wavelengths, becoming an alternative method independent of the spectral index to constrain the dust grain size. The high angular resolution and sensitivity of ALMA enable us to trace the polarization down to 0.3%, previously unattainable. We propose polarization continuum observations at Band 7 at a spatial resolution of 0.18 arcsec for the planet-hosting disk around HD 100546, to characterize the linear polarization across this disk for the first time. Dust evolution modeling suggests particle trapping by embedded planets as the origin of the two mm-sized dust rings seen in previous observations. Our theoretical calculations show that polarization due to dust scattering leads to a distinctive ring structure with a degree up to 1% after beam convolution. Investigating the spatial distribution of polarization will bring significant insights on the evolution of dust particles and on the properties of the potential planets. | Disks around high-mass stars | Disks and planet formation | 2018-05-23T17:06:51.000 |
| 3350 | 2022.1.01414.S | 14 | The molecular ISM and dust emission of extremely red quasars at high spatial resolution. | Feedback from accreting supermassive black holes is now a standard ingredient in galaxy formation models. It may be necessary to recreate the steep high-mass end of the stellar mass function and establish the black-hole/bulge correlations. We request ALMA observations to map the distribution and kinematics of the molecular interstellar medium (ISM) and star formation activity in near-Eddington red quasars at z~2.5 with extreme (>> 1000 km/s) outflow activity well beyond that seen at any redshift among any quasar sample. We will observe the CO (7-6) and [CI] 2-1 emission lines and the rest-frame 375 micron dust continuum at 1-2 kpc resolution. We will search for and measure the energetics of the molecular outflows and map their location relative to the ongoing star formation activity. The selected targets will be observed with JWST NIRSpec IFU to map galactic scale ionized gas kinematics and dynamics. ALMA and NIRSpec observations will allow us to measure the location of the fast-moving (>> 1000 km/s) ionized outflows relative to the molecular ISM and star formation activity to gauge the impact of the powerful outflows on star formation activity and the molecular gas reservoir. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-05-17T13:02:20.000 |
| 3351 | 2016.1.00710.S | 61 | Probing magnetic fields in the inner envelopes and outer disks of Class 0 protostars | Cycle 2 Band 7 dust polarization observations toward 3 Class 0 protostellar cores in Serpens have revealed astounding filamentary structure, suggesting that we have detected the first magnetized protostellar accretion flows. Here we propose for follow-up observations to infer the magnetic field morphologies where the envelope meets the disk (0.06", ~25 AU scales). We also include a Band 3 Science GOal to probe infall along the filamentary structures evident in the Cycle 2 maps. With these observations, we will (1) determine whether B-fields are toroidally wrapped by envelope/disk rotation, (2) probe gas motion along magnetized accretion flows, and (3) characterize the role of magnetic fields in the fragmentation process in a massive, gravitationally unstable disk. In light of preliminary 0.3 (150AU) resolution Cycle 2 polarization maps (Figure 1), we submitted a Cycle 3 change request to observe these three sources with even higher (0.08; 30AU) resolution. The request was approved; comments from the change-request committee included, "One way or another, ALMA should ensure the observations are made; the science may well be transformational." (ALMA Helpdesk ticket #8140) | Low-mass star formation | ISM and star formation | 2019-04-24T01:10:50.000 |
| 3352 | 2016.1.00771.S | 62 | The ALMA edge: Probing the Gas Structure in Edge-on T Tauri Disks | We propose to map two large edge-on protoplanetary disks in the nearby Taurus and Ophiuchus star-forming regions in the 2-1 transitions of the three main CO isotopologues. The edge-on geometry of these objects allows us to measure directly a number of key physical and chemical properties of T Tauri disks, in particular their vertical (and radial) extent in both gas and dust, and the abundance of molecules in the UV-shielded midplane, where ice formation should result in a dramatic decrease of the molecular content. Mapping the spatial distributions of gas (and large dust grains in the continuum) with ALMA will complement the high-resolution HST optical scattered light images that we recently obtained and which map the smallest dust grains. This will allow us to probe the degree of vertical stratification and radial migration of solids in these disks with unprecedented details. These are key issues for a better understanding of the physical and chemical processes at play during the early stages of planet formation. | Disks around low-mass stars | Disks and planet formation | 2018-03-02T09:08:47.000 |
| 3353 | 2017.1.00199.S | 44 | Turning Back the Clock: A Rigorous t=0 for Global Interstellar Chemistry via Collisional Ring Galaxy Observations | Our current understanding of the chemical and physical evolution of systems from galaxy scales to protoplanetary disks is hindered by the lack of rigorously-defined starting times for these evolutionary events. Collisional ring galaxies provide a well-modeled dynamical evolutionary system with a defined starting time (t=0). We propose to exploit ALMA's sensitivity and spatial resolution to observe key molecular species that trace distinct chemical evolutionary timescales within Arp 147, a prototypical collisional ring galaxy. We will couple the dynamical evolution of the impacted galaxy with cutting-edge chemical models, already being applied to local, but not temporally-constrained, shocked sources. This will enable us to rigorously determine the temporal evolution of the most fundamental reactions underpinning complex chemical networks for the first time | Astrochemistry | ISM and star formation | 2019-10-11T15:39:54.000 |
| 3354 | 2024.1.01623.S | 0 | Mining for atomic carbon in protostellar jets | Protostellar jets play a pivotal role in the star formation process, yet their chemical composition remains a puzzle. Carbon, as one of the main constituent of the ISM is expected to be present in protostellar jet, however, it has not been detected so far. In a quest to secure first detection of atomic carbon in protostellar jets, we target 16 Class 0 protostars in Orion molecular cloud. Those sources are also targeted by JWST large program. By securing the detection of atomic carbon we will relate its abundance and kinematic structure with molecular component of the jet, revealed by archival ALMA observations and with the ionized jet probed by JWST. This coordinated ALMA and JWST effort will reveal the full chemical content of protostellar jets. | Outflows, jets and ionized winds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3355 | 2013.1.00428.S | 41 | Dark Molecular Gas | The common, familiar tracer for molecular hydrogen (H2) is CO emission. However, H2 without CO emission, called "Dark Molecular Gas", turns out to be surprisingly abundant, roughly equal in mass to the more familiar CO-traced H2. Even so, many astronomers are only dimly aware of its existence. Dark Molecular Gas represents the transition between atomic gas and the familiar form of H2--the initial stages of star formation, which lies at the very heart of modern astrophysics. To explore the conditions that lead to this transition, we propose a broad frontal attack on Dark molecular gas, consisting of (1) using ALMA to measure the lowest three rotational lines of HCO+ and CO in absorption against the two strong mm-wave continuum sources 3C454.3 and 3C207; (2) using ALMA to survey the (J=1-0) lines of HCO+ and CO against 15 strong mm-wave continuum sources; and (3) mapping CO, HCO+, and HI emission using various telescopes around the world. In absorption, ALMA can accomplish in minutes what requires hours at CARMA, making such a systematic study feasible. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-11-06T06:42:17.000 |
| 3356 | 2016.1.00829.S | 15 | Dense Gas Properties within 40 pc of a Super Star Cluster | Super Star Clusters (SSCs) are some of the most extreme examples of star formation in the Universe. This mode is important when star formation gets very intense, especially at high redshift, but is quite rare in the local Universe. NGC 5253 is the nearest example of a young SSC (proto-globular cluster). At 3.5 Mpc, we can be study the ISM - SSC connection down to within ~10 pc of a 2 Myr old, 10^9 Lo star cluster. Capitalizing on our previous ALMA observations that detect HCN(1-0) and HCO+(1-0) in this low metallicity dwarf starburst for the first time and find very anomalous gas properties, we propose to observe HCO+(3-2) and HCN(3-2) simultaneously at sub-arcsecond scales to map out the ISM properties in the SSC environment. The goal of the project is to constrain the ~10 pc scale structure and kinematics of the dense molecular component and to determine dense gas excitation at ~40 pc scales. This will provide the closest look at the influences of SSC feedback on its molecular environment. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2018-05-12T16:23:45.000 |
| 3357 | 2018.1.01381.S | 83 | The nature of the IRAS16293-2422 outflow and its impact on protostellar chemistry | Outflows are crucial for star formation. One example is how they affect the chemistry by heating gas in accretion/ejection bursts. Evidence of such bursts are recorded in the large-scale outflow, that traces events from the past 10^3-10^4 years. Thus, outflows may serve as an interface between chemistry and protostellar evolution. One of the best studied low-mass protostars is IRAS16293-2422. The system consists of sources A and B, and these show markedly different chemical make-ups. This difference is interpreted as either the B source being more evolved, or it has recently experienced a burst but is currently quiescent. On small arcsec scales, B does not appear to drive a strong outflow but may have done so in the past. To connect the large-scale arcmin outflow to the small scales and map the outflow history, we propose to map the entire outflow with the ACA in CO 3-2 at a resolution of few arcsec, necessary to connect the spatial scales. This will provide the first evidence of bursts changing the chemistry of protostars, a result which is important for understanding the chemical composition of any protostellar system. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2020-09-12T09:56:11.000 |
| 3358 | 2015.1.00645.S | 21 | Tidal Dwarf Galaxies: key probes for understanding dark matter and star formation | Gravitational interactions between galaxies can extrude debris like tidal tails. Tidal Dwarf Galaxies (TDGs) can form in these debris. The tidal interactions effectively segregate dynamically-cold baryons from dynamically-hot dark matter (DM), hence we expect TDGs to be largely devoid of DM contrary to typical dwarfs. TDGs also have higher metallicities than typical dwarfs, having originated from more massive galaxies. TDGs thus serve as important testbeds of galaxy dynamics and star formation (SF). We propose CO(1-0) observations of three TDGs with single-dish CO detections. VLA observations show that TDGs have rotating HI discs and are consistent with our expectations on their dynamics, but the limited spatial resolution also admits other interpretations. ALMA is the only facility that can resolve these gas discs both spatially and in velocity. We aim to derive high-quality velocity fields and rotation curves to build mass models of TDGs and investigate any DM content (baryonic or non-baryonic) they may retain from the discs of their progenitors. We will also combine CO maps with multiwavelength observations to study the spatially-resolved SF law in these unusual dwarf galaxies. | Merging and interacting galaxies | Galaxy evolution | 2017-04-08T01:51:44.000 |
| 3359 | 2011.0.00061.S | 0 | Imaging study of molecules in the nearby galaxies NGC 1068 and NGC 253: Effects of active galactic nucleus and starburst on the shock/dust related molecules SO, HNCO, CH3OH, and CH3CN | We propose to observe shock/dust related molecules SO, HNCO, CH3OH, and CH3CN toward nearby galaxies NGC 1068 and NGC 253 at 3mm and 1mm wavelengths. So far more than 40 molecular species have been found in external galaxies. The study of their molecular abundances and the understanding of physical and chemical processes are a fundamental for astrophysics and astrochemistry of galaxies. One of the interesting topics is the effect of X-ray produced by AGN (active galactic nucleus) to molecular abundances. We carried out molecular line survey observations toward the nearby galaxy NGC 1068 with AGN and the prototypical starburst galaxies NGC 253 and IC 342 with the Nobeyama 45m radio telescope. Based on these results, we propose an imaging study with efficient frequency settings covering astrochemically important shock/dust related molecules SO, HNCO, CH3OH, and CH3CN. The effect of X-ray is not yet well understood. We study whether these molecules are efficiently produced in gas close to AGN or in gas with starburst. For this purpose we obtain images and abundances of these molecules. We need at least two transitions for each molecule to obtain the abundances without assuming the excitation temperatures. Therefore we observe images at both 3mm and 1mm wavelengths. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2013-05-10T04:17:00.000 |
| 3360 | 2024.1.00752.S | 0 | Dissecting the build-up of z>6 massive galaxies with ALMA, MUSE, and JWST | In the first Gyr after the Big Bang (z>6), the tumultuous growth of massive black holes (M_BH~1e9Msun) and of their host galaxies (SFR=100-1000Msun/yr) consumed immense gas reservoirs (~1e11Msun). As a matter of fact, both cold (<100K) and cool (~10000K) gas has been detected in and around these galaxies via their [CII]158um, LyAlpha, or nebular emission. However, we still don't know how much of this material is pristine gas accreting from the circumgalactic medium, or chemically-enriched gas blown out by star formation or AGN feedback. Here we propose to target the OH119um line to unveil the molecular outflows in 3 QSOs targeted with ALMA, VLT/MUSE and JWST/NIRSpec IFU. The data in hand shows prominent LyAlpha halos and signs of outflowing ionized gas (via the [OIII]5007A line), but these ionized gas ejections carry too little mass to affect the hosts' evolution. This study will dissect the interplay between different gas phases and constrain the outflows in the molecular phase (intimately connected with the host's ability to form stars), ultimately this will shed new light on how the evolution of the multi-phase gas shapes the growth of the first massive black holes and galaxies. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 3000-01-01T00:00:00.000 |
| 3361 | 2019.1.01770.S | 206 | The Power of Outflows in Low-Metallicity Star Formation | Although massive stars play essential roles through cosmic history, the formation of massive stars is still poorly understood, particularly in the low-metallicity regime. The metallicity dependence of massive star formation is crucial to understand because the metallicity increases with the cosmic time. Here we propose the first comprehensive survey of molecular outflows from massive protostars in the Large and Small Magellanic Clouds (LMC and SMC). The high-resolution of 0.1pc, which is the typical size of cloud cores, is required to detect molecular outflows. We use the CO (3-2) line at Band 7 as the outflow tracer to achieve the high-resolution and the high-sensitivity. In order to study both the metallicity dependence and the luminosity dependence, we select 30 massive protostars from the LMC (~1/3Zsun) and 10 massive protostars from the SMC (~1/5Zsun) at the luminosity range of 1e4-2e5 Lsun. Whether the Magellanic outflows are consistent with the well-known Galactic correlations or not, our proposed observation will provide the community with the first observational guiding principles for star formation at low-metallicity in 0.1pc scale. | Outflows, jets and ionized winds, Magellanic Clouds | ISM and star formation | 2021-07-01T00:00:00.000 |
| 3362 | 2016.1.00854.S | 13 | High-Precision Measurement of the Black Hole Mass in NGC 3258 | We propose to obtain a CO(2-1) observation of the giant elliptical galaxy NGC 3258 at 0.1 arcsecond resolution in order to measure its black hole mass to high precision. In Cycle 2 we began a program to identify optimal targets for measurement of the masses of supermassive black holes in early-type galaxies by mapping the kinematics of circumnuclear molecular disks. Our Cycle 2 observation of NGC 3258 at 0.44" resolution demonstrates that the circumnuclear gas disk is in near-perfect circular rotation and it clearly exhibits the signature of high-velocity rotation around the central black hole, but the black hole's sphere of influence is unresolved in the Cycle 2 data. With a stellar velocity dispersion of 260 km/s, the expected black hole mass is ~10^9 Msun. New CO(2-1) observations at 0.1" resolution will highly resolve the black hole's dynamical sphere of influence, enabling us to determine the black hole mass accurately via dynamical modeling of the disk rotation. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2018-08-22T12:16:39.000 |
| 3363 | 2016.1.01117.S | 11 | Fine tuning AGN feedback | Super massive black holes in the hearts of the most massive galaxies, situated at the centers of massive galaxy clusters, are known to have dramatic effects on the evolution of the host galaxy and the galaxy cluster. This feedback is extremely well regulated such that the hot X-ray emitting gas and black hole feedback must be well coupled in these systems, whether this is from direct hot gas accretion or colder gas coupled to the hot gas. Only two galaxies, M87 in the Virgo cluster and NGC 4696 in the Centaurus cluster, are near enough and massive enough for us to observe cold molecular gas within the Bondi accretion radius of the super massive black hole. NGC 4696 is farther, yet more massive and it is the nearest such galaxy to have detected, extended molecular gas, making it the ideal candidate. Here we propose to make the first observations of cold gas at within the Bondi radius in NGC 4696. ALMA is the only telescope able to probe molecular gas within a BH sphere of influence. In addition we will probe the nature of the molecular outflows which are likely to provide a key clue to why these massive galaxies remain quiescent. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-01-26T01:00:44.000 |
| 3364 | 2018.1.00588.S | 78 | Probing the stellar IMF in main sequence galaxies in the early Universe | We request ALMA observing time in order to built on our success of using it as a powerful new probe of the stellar Initial Mass Function (IMF) in dusty starburst galaxies (Zhang et al. 2018 Nature). Isotopes of CNO elements are solely produced by stellar nucleosynthesis, and ejected into interstellar medium (ISM) imprinted with IMF. Accomplished with galactic chemical evolution modelling, which is well-benchmarked against rich data in the Milky Way, the 13CO/C18O line ratio has been demonstrated as a powerful tool for probing stellar IMF in galaxies across cosmic time. This opens up a unique new window of exploring fundamental issues of galaxy evolution in the Early Universe, exploiting recent advances in stellar physics. Our current request for ALMA observations seeks to expand the scope of our investigation in starbursts to include the IMF and dense gas fraction in main sequence galaxies in the early Universe, which contribute most of the cosmic star-formation. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-02-18T16:15:35.000 |
| 3365 | 2019.1.00416.S | 34 | The Hidden Compton Thick Nucleus of the Southern Starburst Galaxy NGC4945 | The AGN and starburst galaxy NGC4945 is one of the most prolific molecular lighthouses outside the Local Group. Having published spectacular band 3 results (beamsize 2") and making use of the spectral versatility and unique spatial resolution and sensitivity of ALMA, here we propose band 3 observations with 0.3" resolution: (1) to resolve the nuclear core, (2) to study its connection with the nuclear disk farther out, (3) to define its connection with the H2O megamaser disk further inside, (4) to search for a nuclear torus, (5) to resolve the nuclear disk along the minor axis and to refine the nuclear disk model, (6) to search for S-shaped isovelocity contours hinting at an inner bar, (7) to quantify the displacement between the peak of the star formation and the AGN, (8) to reveal first rudimentary information on excitation conditions, and (9) to determine the enclosed mass as a function of radius. A beam of 0.3" provides the optimal bridge between the previous observations (2") and the size of the megamaser disk (0.05") and offers, with the unique linear resolution of 5-6 pc, a direct look into a Compton-thick active nuclear environment. | Starbursts, star formation | Active galaxies | 2021-04-30T22:56:58.000 |
| 3366 | 2015.1.01253.S | 101 | Deuteration in High Mass Star Formation | High mass stars play a dominant role in the shaping and evolution of galaxies. However, the formation process and early evolution of high-mass stars is not well understood. Deuterium containing molecular species provide a highly selective probe of the quiescent and cold material in a molecular cloud. N2D+ (3-2) is a well known tracer of dense gas in star forming regions without being affected by depletion as are C-bearing species. The deuteration ratio derived from N2D+ is often used as an evolutionary tracer in star formation. But our recent results show that there is a lack of correlation between the presence of a protostar and the presence of N2D+. Mostly due to the lack of angular resolution prior to ALMA. We plan to observe N2D+ (3-2) towards 6 high mass regions with high deuteration ratio, likely sites for massive star and cluster formation, in order to study the quiescent evolutionary stage of high mass star formation and its association with the 70 micron emission. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-11-25T14:24:36.000 |
| 3367 | 2012.A.00028.S | 0 | A nest of submillimeter galaxies in less than 1 Gyr after the Big Bang: a [CII] emitter group at z=5.7 discoverd by AzTEC/ASTE and SMA | We propose a Band 7 DDT observation of a group of [CII]-emitting dusty starburst galaxies at z=5.65. We recently discovered this group by an extensive blind [CII] emission line survey using SMA over a contiguous 23 GHz bandwidth (z=5.5-6.1) , toward the bright AzTEC-selected submillimeter galaxy SDF1100.001, for which two SMA 1300 micron sources had been identified prior to the [CII] search and their photo-z are estimated to be ~6.1 and 5.7 using optical/infrared data. This group consists of 7 candidate [CII]-emitting galaxies within a 40′′ circular region (~240 kpc at z =5.65) and some of them are associated with mm-continuum sources--such a group of [CII] emitting galaxies at this redshift, or even at lower redshifts, has never been reported to date. The measured [CII]/FIR luminosity ratios, 10^{-2.4} to 10^{-2.1} , strongly support the idea that they are indeed redshifted [CII] lines at z=5.65. Furthermore, the [CII] emitters (hereafter CTEs) discovered by SMA appear to show an elongated or filament-like distribution across the observed ~240 kpc area, suggesting that these intensive starbursts would be supported by gas inflow through “cold-mode” accretion, in addition to major mergers. Considering the importance of our discovery and big impact on the understanding of massive galaxy formation and the environment such as group or cluster in the very early universe, and also that our ALMA observations would make breakthrough in this research area, we propose the DDT observations of this CTE group. We request a total observing time of only one hour for the 40''x40'' area [CII] mapping over a redshift range of z=5.63-5.72. This will provide a >10x deeper [CII] line sensitivity than SMA and ~1" resolution (6 kpc at z=5.65). Our science aims are as follows: 1) Detect [CII] emission from the most luminous SMG possibly with a buried radio-loud AGN for which SMA fails to detect [CII]; 2) Reveal the entire structure of this [CII]-emitter group, by detecting 10x fainter CTEs with a uniform sensitivity to investigate overall distribution and kinematics of the CTE group/cluster; and 3) Measure the FIR luminosity of the [CII] emitters. The proposed observation will also give an 7x deeper 1100 micron continuum image than SMA. This will enable us to study the census of CTEs by obtaining FIR luminosity, [CII]/FIR luminosity ratio, which are essential for the understanding of the nature of CTEs/SMGs in a group or cluster. The proposed ALMA observation and study of this very unique group of CTEs at z=5.65 can allow a better understudying of how massive starburst galaxies and their group/cluster are forming and evolving, and how their environment is in the very early universe less than 1 Gyr after the Big Bang. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2014-11-20T19:51:42.000 |
| 3368 | 2021.1.01126.S | 62 | Unveiling the nature of peculiar embedded icy objects discovered by AKARI | We propose high-sensitivity molecular line observations in Band 6 and 7 to unveil the nature of two peculiar icy objects, which were recently discovered by infrared spectroscopic survey of the Galactic plane with the AKARI satellite. Both objects show deep ice absorption features that are often seen in YSOs or background stars sitting behind dense clouds, but they are located neither in known star-forming regions nor in known dense clouds, and their infrared SEDs are incompatible with existing YSO models. If they are truly YSOs, similar objects should have eluded past photometric surveys, which would require a revision of our view of the distribution of YSOs in a Galactic scale. If they are background stars, there must be dense and very compact clouds in the line-of-sight, which have eluded past dense cloud surveys, or ice species may grow in unknown processes in tenuous clouds. Either case will make a significant impact on our understanding of the ice chemistry and/or star-formation process in our Galaxy. Their true nature remains uncertain based on the currently available data. The proposed molecular line spectroscopy with ALMA will distinguish their nature unambiguously. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-04-21T07:35:47.000 |
| 3369 | 2018.1.00812.S | 17 | AGN-driven molecular outflows in post starburst E+A galaxies | Mapping AGN-driven outflows is essential in order to assess whether SMBHs can significantly influence the evolution of their host galaxies. Despite significant observational effort with ALMA and other advanced facilities, the answer is still unclear partly because the relative contributions of AGN and supernovae in driving large scale flows is hard to estimate, and partly because there is no well-defined evolutionary timeline that enables to meaningfully compare different systems. We have recently discovered AGN-driven winds in post-starburst E+A galaxies in which such uncertainties are not present. We see AGN-feedback in action, there are no more SN explosions, and the timeline is clearly measured from the spectrum of A-type stars. We request deep CO(2-1) observations to map the mass and kinematics of the molecular gas in two such systems where we already measured the mass outflow rate and the location of the AGN-ionized gas. The goals are to detect, for the first time, AGN-driven molecular outflows in such systems and to establish whether AGN are capable of migrating powerful starburst galaxies to the red sequence. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2020-09-07T00:11:59.000 |
| 3370 | 2021.1.01467.S | 311 | Illuminating the dark side of star formation at z > 3 | We propose an ALMA spectral scan observation in band 3 (3mm) to spectroscopically confirm the redshift of 9 UV-dark radio galaxies. The cosmic star formation rate density has been reliably traced back to 10-11 billion years after the Big Bang; however, its evolution is still poorly constrained at earlier cosmic epochs, and biased towards galaxies luminous in the ultraviolet and with low obscuration by dust. An approach to search for dust-obscured galaxies based on their emission at radio wavelength has been recently proved to be very effective in finding candidates at very redshifts. From a radio-selected sample in the COSMOS field, 22 galaxies have been identified to be at zphot>4.5. The contribution of these elusive systems to the SFRD is substantial and can be as high as 40% of the previously known SFRD based on UV-luminous galaxies. However, in order to validate this exciting result it is needed to unambiguously confirm the redshifts of such extremely obscured galaxies. This can be achieved effectively only with the proposed ALMA observations. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-02-02T04:05:44.000 |
| 3371 | 2012.1.00564.S | 0 | The initial conditions of massive star formation: Chemistry in cold IRDC cores seen with ALMA. | Recent studies suggest that massive stars form in cold cores embedded in massive infrared dark clouds with typical masses of 10E3 Mo and a temperature of <20 K. As a result of protostellar heating, cold cores evolve to hot molecular cores characterized by profuse line emission of organic molecules. Very little is known about the physical and chemical state of the cold phase and their evolution. We take advantage of the very recent high resolution FIR data from Herschel and select 8 massive molecular clumps (>500Mo) with SEDs peaking at dust temperatures around 15-25 K. These IRDC clumps have been recently imaged with the SMA at 1.3mm. The SMA images reveal an evolutionary trend for which the IRDC cores can be classified as cold (Tgas<20 K), warm (Tgas=45-50 K) and hot (Tgas>100 K). Since the SMA is sensitivity limited for the cold IRDC cores, we propose to use the unprecedented sensitivity of ALMA in its Cycle 1, to study for the first time the physical and chemical evolution of dense cores prior to the warm and hot core phase. This proposal exploits synergies of the unique high-angular-resolution, high-sensitivity spectral line/continuum capability of ALMA, and the high resolution FIR photometry and spectroscopy of Herschel. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2015-07-07T20:10:37.000 |
| 3372 | 2016.1.01286.S | 18 | Resolving multiple ring structures in protoplanetary disks | We propose to obtain line and continuum observations of two protoplanetary disks, J1615 and HD97048, that show multiple rings in our high angular resolution optical scattered light images. We aim to understand the origin of these rings by resolving these regions with ALMA at a similar angular resolution (~0.06"). By comparing the observations that on one hand, trace micron-sized particles (SPHERE/VLT) and on the other hand, probe mm-sized grains (ALMA), we will establish whether these rings are particle traps. We will determine the 3D geometry of the disks, which we expect to be strongly affected by planet-disk interaction, in particular in the case of J1615 for which we detected a planetary companion candidate. We will also constrain, through dust evolution models, the efficiency of dust trapping which is related to the strength of the turbulence in the disk. | Disks around low-mass stars | Disks and planet formation | 2019-02-24T05:47:24.000 |
| 3373 | 2018.1.00539.S | 514 | Molecular abundances in the low-metallicity environment of the Far-Outer Galaxy | The metallicity Z of gas in galaxies increases steadily with time, as stars evolve and progressively release heavy elements into the interstellar medium. Low metallicities characterise the outer regions of our own Galaxy, which can in turn modify the abundances of molecules in the clouds formed here. Very few studies have, however, been dedicated to the investigation of the molecular content of clouds in the outer Galaxy, especially for molecules other than CO. The significant difference in metallicity between the inner and outer Galaxy makes a comparative study of abundances in these two regions of the galactic disk the most promising way of assessing the influence of Z on the chemistry, and will allow to test the predictions of the models for these conditions. Because low metallicities are also typical of dwarf irregulars and higher-redshift galaxies, this will be a first step towards a characterisation of the chemistry in molecular clouds in external galaxies and in the early Universe. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-08-11T20:43:00.000 |
| 3374 | 2016.1.00810.S | 18 | What can hubs tell us on massive star formation? | Despite the importance of massive stars in galaxy evolution, the process through which their progenitors are built remains highly controversial. Our ALMA cycle 0 results showed that one of the most massive cores ever observed in the Galaxy is forming at the converging point of a network of dense filaments, or hub. The data suggest that the large infall rate required to form this core is powered by the global collapse of the cloud. Here we propose to perform a first test of the universality of this scenario by mapping the fragmentation and kinematics of 5 massive infrared dark hubs with the objective of determining what key properties of the parental clouds determine the mass of the most massive cores. This is a resubmission of a Cycle 3 proposal, for which all of the requested 12m array observations, and part of the ACA/TP observations have already been taken. Here we request for the completion of the ACA/TP observations of the Cycle 3 proposal. Furthermore, we have included a new target to incorporate the Cycle 3 sample: the SDC335 cloud for which we have the Cycle 0 12m array observations with the same setup (project 2011.0.00474.S), also requiring ACA/TP. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-05-28T00:00:00.000 |
| 3375 | 2021.1.01582.S | 9 | Multi-band polarimetric observations to study grain growth in the Class I protobinary system L1551 IRS 5 | Grain growth is the first step to go toward planet formation and has been studied in young stellar objects at various evolutionary stages. However, grain growth in protobinary systems is little known. From the ALMA archival data taken in Band 3 and 7 toward the well-known Class I protobinary system L1551 IRS 5 that has two circumstellar disks and a circumbinary disk, we have found evidence that grains have grown much and are distributed non-uniformly, by measuring the spectral indexes. However, the spectral index method does not work particularly for optically thick regions. In this project, we will obtain multi-band polarimetric continuum data, particularly in Band 4, 6, and 7, to investigate the grain size and spatial distributions of the protobinary system L1551 IRS 5 in an independent way. The results will provide the whole, more reliable grain distributions of the protobinary system. Also, the method to combine the spectral index and the polarization information, which we develop in this project, will be an excellent example for future observational studies on grain distributions. | Disks around low-mass stars | Disks and planet formation | 2023-10-27T03:05:50.000 |
| 3376 | 2018.1.01136.S | 50 | Resolving a central 600 pc starburst nucleus at z=4.3 | We propose 0.04 arcsec(270 pc)-resolution observations of CO(7-6) in a submillimeter bright galaxy at z=4.3, COSMOS-AzTEC-1. ALMA cycle-3 observations of 860 um continnum emission have successfully revealed the existences of a central 600 pc nucleus, multiple clumps, and an extended 4 kpc disk. Furthermore, ALMA cycle-5 observations of CO(4-3) line show that the extended disk is rotation-supported. The extremely high SFR density of ~1000 Msun/yr/kpc2 in the nucleus suggests that the extreme starburst is caused by a gas-rich major merger while the extended rotaing disk favors a scenario that the disk is formed by smooth gas accretion. The misalignment between the morphological major axis of the nucleus and the kinematic one of the extended disk also suggests that they are formed through a different physical process. With the proposed 0.04 arcsec-resolution data, we will for the first time investigate the kinematic properties in a 600 pc nucleus of SMGs, providing an evidence of a hybrid scenario (gas-rich major merger and smooth gas accretion). | Galaxy structure & evolution | Galaxy evolution | 2020-11-21T11:22:01.000 |
| 3377 | 2012.1.00650.S | 2 | The Role of Galactic Environment in GMC and Star Formation | With the advent of ALMA our understanding of the molecular gas and its bound entities, giant molecular clouds (GMCs), will be revolutionized: Recent results from our study of M51 suggest that the formation, organization and properties of GMCs strongly depend on large-scale galactic dynamics while stellar feed-back might only be important in preferred locations where star formation and GMCs are well-mixed, in short the overall galactic environment determines the shape and properties of the cloud population. These tantalizing findings urgently need confirmation as they have strong implications on the gas depletion time and theories of star formation. Therefore we propose to map the central ~7.5 kpc of the grand-design spiral galaxy M74 in the CO(2-1) line emission to enable the study of its GMC population as a function of galactic environment. M74's gravitational potential is very similar to M51 ones while the surface density of cold gas and star formation is about 5x lower. The resulting 35pc (1 km/s channel width) dataset containing over 1,000 GMCs will address the following questions: Is there a universal GMC mass function? What is the interplay between star formation and the GMC population? Are molecular clouds really self-gravitating/stable entities? What is causing departures from a universal gas depletion time? | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2015-06-13T16:26:06.000 |
| 3378 | 2017.1.01185.S | 38 | Sub-parsec Gas Excitation in the Galactic Center | Measures of gas excitation in Galactic center molecular clouds are lacking on sub-parsec scales. Without these measurements, we lack constraints on the density structure of clouds necessary to test models of star formation in this environment and determine why so many clouds are not forming stars. We also lack a knowledge of the chemical abundance structure necessary to determine the impact of factors like shocks and cosmic rays and how they set the initial chemical conditions for star formation here. We propose to make the first survey of sub-parsec scale gas excitation in the Galactic center by observing a representative sample of clouds in Band 7 with ACA (resolution 3.5) and leveraging existing Band 3 ALMA 12m and Band 6 SMA coverage of these clouds. With 100 mK sensitivity we will detect lines of more than a dozen species, most of which are also mapped at another frequency. This will enable the first measurements of density structure and molecular abundances on sub-parsec scales and build a unique legacy dataset for future study. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-01-27T00:00:00.000 |
| 3379 | 2017.1.00022.S | 353 | AGN feedback and molecular line flux ratios in luminous infrared galaxies | Molecular line flux ratios in the (sub)millimeter wavelength range can be a powerful tool to diagnose obscured energy sources in gas/dust-rich luminous infrared galaxies (LIRGs), because (1) dust extinction is very small, and (2) AGN and star-forming activity show different molecular line flux ratios, due to different feedback to the surrounding molecular gas. It has been argued that elevated HCN emission is observationally a good AGN indicator, but its physical origin is still yet to be clarified. Is it due to (a) higher HCN excitation and/or (b) HCN abundance enhancement in AGNs? Since molecular level population is primarily determined by three parameters, (1) H2 number density, (2) H2 kinetic temperature, and (3) molecular column density divided by line width, we need at least three independent observational constraints to physically understand molecular gas properties. We propose HCN/HCO+/HNC J=2-1 observations of LIRGs with available HCN/HCO+/HNC J=4-3 and J=3-2 data. From the J=4-3, J=3-2, and J=2-1 data, we will be able to, for the first time, obtain the physical understanding of observed molecular line flux ratios in AGN-important and starburst-dominated LIRGs. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2019-02-17T05:28:02.000 |
| 3380 | 2016.1.01288.S | 182 | The molecular gas properties of radio-AGN at z~0.6 | Energetic feedback from AGN is believed to play an important role in the quenching of star-formation in massive galaxies and the subsequent maintenance of the quenched state. However, the on-going physical processes remain poorly understood, as does the relative importance of the two fundamentally different modes of AGN activity (quasar-like AGN vs. jet-dominated AGN). We propose a highly-efficient strategy to study the CO(2-1) molecular gas content of matched samples of 12 radio-AGN from each of the two AGN classes, at 0.45 | Outflows, jets, feedback | Active galaxies | 2018-04-27T22:17:43.000 |
| 3381 | 2019.2.00252.S | 22 | Spectral variations of spinning dust emission in the Oph W PDR: the role of ions. | The anomalous microwave emission (AME) is a dust-correlated emission mechanism that is observed between 10--100\,GHz. It is thought to originate by electric dipole emission from dust grains spinning at GHz frequencies. The photo dissociation region (PDR) rho Oph-W is one of the best and brightest examples of AME. We have detected for the first time a spectral variation of the AME spectrum using ATCA data at frequencies between 5 and 39\,GHz. Within the spinning dust (SD) model, interactions with plasma and ions are expected to be the dominant excitation mechanism in PDRs. To test this hypothesis, we propose to map Carbon Recombination Lines (CRL) using ACA Band 3. We expect to measure variations in the CRL across the PDR that will correlate with the morphology of the ATCA observations. we also expect to measure the electron density across the PDR using the CRL and other molecular lines that fall within the base band (HCO+, H13CO+). This will allow us to constrain the physical conditions that give rise to the spinning dust emission. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2023-07-08T15:24:38.000 |
| 3382 | 2016.1.00170.S | 28 | Multi-phase spatially-resolved outflows in low-z ULIRGs: Mapping the massive cold molecular component | Feedback from violent starbursts and actively accreting black holes around active nuclei is fundamental for shaping galaxy evolution. Such feedback is typically manifest in massive outflows in ionized, atomic, and molecular gas. Using H2 2.12 micron integral-field spectroscopy, we have recently characterized extended (2-3 kpc) high velocity (~1000 km/s, FWZI) hot molecular outflows in low-z IR bright starbursts (1 LIRG, 4 ULIRGs) out of a sample of 17 (10 LIRGs, 7 ULIRGs). Here, we propose to trace the cold molecular gas entrained in the outflows through deep 0.25" CO(2-1) images of three of these ULIRGs with high-velocity, extended, hot H2 outflows. In addition to mapping the cold molecular phase of the outflows on scales of 100 pc, we will establish the mass loading and momentum boost factors, and, for the first time, determine the properties of the gas phases in the outflow (cold/hot molecular and ionized) in the most extreme local star-forming galaxies. Our proposed observations will help quantify the effects of feedback in galaxies, which are extreme locally, but which may be representative of the growth of galaxies at high redshift. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-06-15T01:19:40.000 |
| 3383 | 2018.1.01295.S | 28 | A direct test of the magnetar-model in Superluminous Supernovae | Stripped-envelope Superluminous Supernovae (SLSN-I) are stellar explosions with optical luminosities ~10-100 times that of supernovae (SNe). An extra energy source is required to account for the extreme luminosity, and recent studies favour the model where this is provided by the spin-down of a rapidly-rotating, strongly-magnetized neutron star (magnetar) formed in the SNe. Importantly, this magnetar-engine model could account for the diverse properties across all classes of stripped-envelope SNe. Additionally, Fast Radio Bursts are attributed to pulsars/magnetars in many leading models and might be created in this way. Given the wide-ranging implications of the model, it is vital that we establish if it is valid. We propose to do the first key test to conclusively determine if SLSNe-I are powered by a magnetar central engine. With 4.76 hours of Band 3 and 6 observations of the closest SLSN-I discovered to date (SN2017egm), we will obtain the deepest sub-mm observations of a SLSN-I and search for the sub-mm magnetar signature. With these observations we will either make the first direct detection of a magnetar central engine or rule out the magnetar-engine model. | Supernovae (SN) ejecta | Stars and stellar evolution | 2020-09-24T20:47:40.000 |
| 3384 | 2015.1.00419.S | 42 | WISDOM: Extending black hole demographics across the mass-size plane with ALMA | Ubiquitously present at the centres of galaxies, black holes are central to understanding galaxy evolution. However, the current sample of galaxies with measured black-hole masses is incredibly biased, tracing only specific regions of the mass-size and mass-velocity dispersion planes. As many galaxy properties vary across these planes, this bias could be fundamentally affecting our understanding of black hole scaling relations, and thus the relationship between galaxies and their SMBHs. As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) we have pioneered the use of molecular gas to estimate SMBH masses, and conducted the preparatory work required to select a large sample of suitable ALMA target objects. We here propose to map CO(2-1) at high resolution, in a sample of objects which span the unexplored areas of the mass-size plane, accurately measuring their SMBH mass. In this way we can address this bias, extending SMBH demographics, and shed light for the first time on potential variations of SMBH-galaxy correlations using the same technique (with the same systematics) across the galaxy mass-size plane. | Galactic centres/nuclei | Active galaxies | 2017-08-05T18:44:50.000 |
| 3385 | 2016.1.00209.S | 453 | Multi-scale disk and envelope kinematics around the most extremely accreting young stars | The transition between the embedded and the disk-only phases is a milestone in the life of a young star. This is when the object crosses the birthline, appears at visible wavelengths, and starts its protoplanetary evolution. How this transition from the Class I to the Class II phase happens is little known. The hypothesis of Green et al. (2006) and Quanz et al. (2007) is that this is driven by FU Orionis-type (FUor) eruptions. Here we propose ALMA observations to explore this transition via studying the southern FUor sample. We will perform a multi-scale study of both the dust and gas components, as successfully tested in our pilot study on V346 Nor. We will spatially resolve the disks and envelopes, and check if their properties outline trends predicted by the evolutionary hypothesis. We will (1) characterize the spatial and velocity structure of the circumstellar gas; (2) model the structure and kinematics of FUor disks; and (3) model the FUor envelopes and analyze evolutionary aspects. The results, supplemented by our earlier measurements of northern FUors, have the potential to verify or disprove our hypothesis, and settle a highly important question of early stellar evolution. | Low-mass star formation | ISM and star formation | 2018-04-03T18:10:08.000 |
| 3386 | 2022.1.01740.V | 0 | A detailed study of the sub-pc jet of BL Lacertae at mm-wavelengths with the EHT+ALMA | AGN jets are key objects to broaden our knowledge of the Universe, on Black Hole and galaxy evolution, and on the impact of magnetic fields on this. Here we propose a joint observation on the nearby and archetypical AGN object BL Lacertae (BL Lac) with the EHT+ALMA at 1.3mm and in close coordination with the GMVA+ALMA at 3.5mm. By scheduling the 1.3mm and 3.5mm observations near-in-time (April/May 2023), we can image and study the innermost jet launching region on sub-parsec scales, a region which is still poorly understood. BL Lac is particularly close (redshift~0.069) and has a bright radio jet (overall > 3 Jy at 1mm). More importantly, its jet is highly polarized also in its inner region (close to the central engine). This facilitates a spectral index and rotation measure study with a spatial resolution of up to ~1600 Schwarzschild radii. We aim to study the configuration and strength of the jet magnetic field, the collimation/acceleration profile, and the physical conditions in the region close to the central, powering supermassive black hole. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-09-20T11:52:59.000 |
| 3387 | 2021.1.00511.S | 96 | A unique ALMA view: a pilot study of turbulent multi-phase high-redshift protocluster regions exploiting OH+ and CH+ | Galaxy protoclusters, progenitors of todays clusters of galaxies, are characterized by enhanced star formation and AGN activity, and therefore host some of the most turbulent multi-phase regions in the universe. While, currently, extended gas reservoirs in protoclusters are mainly probed through Hydrogen Lyman-alpha emission, the complex radiative transfer of this line hampers a firm characterization of the gas kinematics and physical properties. Additional independent tracers beside the Lyman-alpha are therefore needed to overcome such limitations. In this framework, two light hydrides, OH+ and CH+, are unique diagnostics of the kinematics (inflow or outflow, turbulent velocity), cosmic-rays ionization rates, and kinetic energy injected in diffuse molecular gas. Interestingly, a recent experiment comparing Lyman-alpha and CH+ observations around a z~3 group environment found co-existence of the two thermal phases over at least 40 kpc. We therefore propose a pilot ALMA band 5-6 program to characterize 5 well-known z~3 protocluster regions exploiting the chemistry of OH+ and CH+. This program will pave the way for detailed studies of multi-phase turbulent regions in protoclusters. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2023-05-10T11:22:54.000 |
| 3388 | 2021.1.00982.S | 142 | A survey of H2CO lines in protoplanetary disks | Protoplanetary disks contain the organic material that will be incorporated into planets. Resolving the spatial distribution of the complex organic material in disks is therefore of great interest to predict their potential ability to form life-harboring planets. Unfortunately, O-bearing complex organic molecules (COMs) are hard to detect in disks. The small organic molecule H2CO, is a precursor of COMs that is bright in disks, and therefore provides a view into the spatial distribution of COMs in disks. We propose to observe several transitions of H2CO towards four well-studied nearby protoplanetary disks. By observing several H2CO lines, we will directly measure the excitation temperature as a function of radius, and derive both the radial and vertical distribution of the H2CO emission. The four disks have different temperature and density structures, which will allow us to determine how H2CO is formed in different disk environments. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2023-09-28T23:32:19.000 |
| 3389 | 2018.1.00962.S | 186 | Astrochemical ABCs - An ALMA Band 9/10 Chemical Survey of NGC 6334I | Recent ALMA observations by the proposers have revealed that the massive star-forming region NGC 6334 I is one of the richest and most diverse sources of chemical complexity in the galaxy, and may very well turn out to be a hot spot in the molecular universe. ALMA Band 7 observations indicate the presence of a variety of physical sources across evolutionary stages, including several hot cores. Here, we propose to leverage the power of ALMAs Band 9 and 10 receivers to operate in dual side band mode to conduct a full Band 9 and a pilot Band 10 astrochemical survey of this region with relatively modest time requirements. The resulting spectra will provide insight into the chemical differentiation by probing simple, light species not readily accessible at lower frequencies, rigorously constrain the excitation of complex organic molecules with a higher-energy anchor to existing lower-frequency data, and dig into the inner reaches of the brightest hot core with high-excitation probes of physical conditions. The resulting spectral line surveys will be made publicly-available. | Astrochemistry | ISM and star formation | 2020-09-06T22:14:23.000 |
| 3390 | 2016.1.00803.S | 42 | Debris Disks Around Tau Ceti and Epsilon Eridani | At 3.65 and 3.22 pc, respectively, Tau Ceti and Epsilon Eridani are the two closest Solar analogues to host detectable debris disks. In addition, both stars are reported to host planets within a few AU detected by radial velocity variations. The presence of additional planets, and their role in the dynamical evolution of these nearby systems, could be revealed by their influence on the surrounding debris disks. We propose ALMA ACA-only observations to resolve the millimeter continuum emission from the Tau Ceti and Epsilon Eridani debris disks. By combining these data with dynamical simulations, we will (1) robustly measure the locations of the disk inner and outer edges and their position relative to the radial velocity planetary systems, (2) quantify the disk surface density gradient and assess whether these systems are stirred by the influence of an additional massive planet within the disk or self-stirred and collisionally depleted from the inside-out, and (3) use disk features such as offsets and azimuthal asymmetries to place constraints on otherwise inaccessible wide-separation planets. | Debris disks, Exo-planets | Disks and planet formation | 2019-06-20T00:00:00.000 |
| 3391 | 2021.2.00012.S | 0 | Unveiling cold molecular gas in the blue compact dwarf galaxy NGC 2915 | To understand galaxy evolution, it is fundamentally important to determine the amount of H2 that is the cradle of star formation. CO has been used as a tracer of H2 which is not directly observable, but it has been argued that CO is not necessarily a reliable tracer in low-metallicity and UV-intense environments. CI has been expected to be a better H2 tracer in such environments, but the suitability remains unproven observationally. In this study, we will measure the distribution of CI and CO in the nearby blue compact dwarf galaxy NGC 2915 and compare them with that of cold dust, another reliable tracer of cold gas, to clarify which [CI] or CO is the better cold gas tracer in the environments. We have already obtained distributions of the dust surface density and temperature from spectral energy distribution (SED) fitting of optically thin infrared dust emission. Through the relationships between the lines and dust, we will simultaneously determine the conversion factors of alpha_[CI] and alpha_CO, and gas-to-dust ratio, resulting in the amount of cold H2 in the galaxy. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2023-09-20T04:03:16.000 |
| 3392 | 2019.1.00236.S | 44 | Strongly Lensed HST-dark Object Discovered by ALMA Lensing Cluster Survey | We propose Band 3 and 8 observations for a strongly lensed (magnification~6-8) object MJ0553-ID19 that has been identified in our on-going ALMA large project of the lensing cluster survey (2018.1.00035.L). MJ0553-ID19 is clearly detected at the 8.5 sigma level (~1 mJy) in the ALMA 1.2-mm map with faint detections in the IRAC/ch1-2 bands, but unseen in any HST/ACS-WFC3 bands. Our analyses suggest that MJ0553-ID19 is a new population of low-mass (Mstar < 10^10 Msun, SFR < 50 Msun/yr) dusty galaxy at z > 4 which may significantly contribute to the cosmic star-formation history (CSFH) in the early Universe. Our major goals are determining the spectroscopic redshift via the CO line and evaluating the contribution of the low-mass dusty galaxy to the CSFH at z > 4 with the exact dust temperature measurement. If we perform the same observations towards similar objects as intrinsically faint as MJ0553-ID19 (~0.1 mJy) without the lensing support, at least 300 hours are required. This program is thus the only path to unveil the new population of low-mass dusty objects that have been missed in the previous optical-NIR surveys, but discovered thanks to the power of ALMA+lensing. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2021-04-11T00:00:31.000 |
| 3393 | 2013.1.00880.S | 10 | A Pilot Study to Detect Dark Matter Subhalos with ALMA using Strongly Lensed submm Galaxies | We propose to observe five strongly lensed, dusty, star forming galaxies for ∼ 40 minutes per source in CO emission lines in bands 4 and 6 to detect dark matter subhalos in the lens galaxies using gravitationally-induced perturbations they cause on the images of background sources. With detailed simulations, we have shown that ALMA is capable of efficiently detecting subhalos in these systems, if the abundance of subhalos is in agreement with ΛCDM predictions. We have built and tested a complete pipeline to search for and detect subhalos using ALMA data. This proposal is a pilot study for the analysis of the large population of bright lensed dusty galaxies discovered in submm bands to detect dark matter subhalos, allowing us to measure their mass function with unprecedented accuracy and thereby resolve one of the most important puzzles in modern cosmology. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2016-08-21T00:27:37.000 |
| 3394 | 2021.1.00458.S | 6 | Dust polarisation in distant, star-foming galaxies: a transformative survey of the viable targets | Magnetic fields play arguably the most poorly understood role in our galaxy evolution paradigm, yet it is likely an important one. Well-ordered uG galactic magnetic fields have been found in nearby galaxies, like most recently by SOFIA in M82 and NGC1068, but we have essentially zero knowledge about galaxies beyond z~1. Here, we propose a potentially transformative survey of the dust polarisation, targeting the three most viable galaxies at z>1 - those that are sufficiently bright, spanning cosmic noon to cosmic dawn, with ordered rotating disks, whose polarisation can be mapped across multiple resolution elements. Our observations will 1) measure the magnetic fields strength in dusty, star-forming galaxies, and the degree to which it is ordered, testing evolutionary links to plausible descendent galaxy populations in the local Universe, and their similarity to local starbursts; 2) explore magnetic fields across a considerable fraction of cosmic history, constraining the timescale of the dynamo mechanism. Together with archival continuum imaging, we will also be sensitive to giant molecular clouds, whose presence in SMGs is controversial, with all necessary baselines represented. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-01-25T13:25:02.000 |
| 3395 | 2019.2.00098.S | 90 | Triggering and supression of star formation in recent gas-rich minor mergers | Galaxy mergers are a crucial part of our galaxy evolution paradigm. Gas-rich & gas-poor mergers have been well studied. However a third intermediate class exists, where one of the merging objects has gas, and the other does not (gas-rich+gas-poor). Such mergers are quite common at low redshift, but have not been well characterised. A recent study suggests that mergers where a gas-rich minor companion is accreted onto a gas-poor central actually lead to very low efficiency star formation, in stark contrast to the starburst often observed in purely gas-rich mergers. In order to understand this phenomenon we here propose to observe a carefully constructed sample of gas-rich+gas-poor & gas-rich minor mergers with the ACA, revealing the compactness/dynamical state of their molecular reservoir, and how this relates to their star formation efficiencies, & those of a robust control sample selected from the literature. A short investment of ACA time will allow us to reveal how gas gas-rich+gas-poor mergers differ from better studied gas-rich mergers, and lay the ground work for future observational & theoretical efforts to fully resolve the physical processes behind these differences. | Merging and interacting galaxies, Early-type galaxies | Galaxy evolution | 2022-10-05T11:07:33.000 |
| 3396 | 2018.1.00006.S | 100 | Testing the Effectiveness of AGN Feedback in Quasars | Energy feedback from active galactic nuclei (AGNs) is widely believed key to regulate star formation and build up the correlations of massive black holes and their host galaxies. However, the observational evidence for AGN feedback is still illusive. Gas outflows, frequently observed in AGN host galaxies, are suspected capable to deplete the interstellar medium, remove the obscuration of the AGN, and quench star formation. However, our recent work based on accurate global measurements of dust mass from Herschel finds the total gas fraction of low-z quasars resembles that of normal galaxies, casting serious doubt on the efficacy of AGN feedback. In Cycle 5 we initiated an ACA CO(2-1) survey of 23 low-z quasars to better constrain their molecular gas content. We detect abundant molecular gas in most of the targets observed by far, but the band 6 ACA resolution fails to yield useful information on the spatial distribution and velocity field. We propose follow-up ALMA CO(2-1) observations of the six brightest ACA detections at sub-kpc resolution to test the effectiveness of AGN feedback, which should have significant impact on the spatial and kinematic distribution of the gas. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2020-09-06T21:58:35.000 |
| 3397 | 2018.1.01521.S | 19 | The first kpc-scale map of the cold molecular ISM in a z=1.1 main sequence galaxy | We propose to map the low-J CO(2-1) line across the full disc of a carefully selected z=1.1 main sequence galaxy in the Hubble UDF at unprecedented 0.13" (1 kpc) resolution. Our data will provide the first kpc-scale gas, velocity and dispersion map of any z~1 galaxy. The target is ideally suited for this project: it is detected in CO with the ASPECS large project, has rich ancillary data, and is sufficiently extended to be resolved with many dozens of beams. Combined with in-hand star formation tracer maps (Halpha, UV), we will carry out a pioneering study of the molecular clump lifecycle at the peak of cosmic star formation. Using the spatially-resolved relation between star formation and gas tracers on scales of only 1 kpc, we will make the first robust measurements outside of the local Universe of critical, hotly debated quantities, such as the clump lifetime, star formation efficiency, feedback timescale, feedback outflow velocity, mass loading factor and feedback efficiency. This project will address crucial open questions, such as the role of clumps in bulge growth, disc instability scales and the disc baryon fraction, and present a poster child of ALMA's unique capabilities. | Galaxy structure & evolution | Galaxy evolution | 2022-11-28T18:33:50.000 |
| 3398 | 2021.1.01295.S | 72 | Chasing molecular outflows in local Seyferts with the deepest ACA CO observations | Molecular outflows are thought to be the dominant component by mass in galactic winds. Their detection statistics in Seyfert galaxies remains, however, very limited. The possibilities to explain this are the following: i) The sensitivity of current observations is not sufficient to detect them, especially in weaker sources as Seyferts; ii) Molecular outflows are actually absent in most cases and represent only a rare phenomenon; iii) An important fraction of molecular outflow emission is diffuse and is resolved out in 12m array observations, that are only sensitive to small-scale clumpy emission. We propose unprecedentedly deep (10h exposure time per source) ALMA ACA 7m observations of 8 nearby (<40 Mpc) Seyfert galaxies aimed at detecting molecular outflows from broad wings of the CO(2-1) line. We will be sensitive to outflow masses as low as 5*10^4-10^5 solar masses and recover diffuse emission in the outflow, if present. The matching with existing VLT/MUSE optical data will provide the total (molecular+ionised) outflow mass and energetics, that will allow to assess the impact of outflows on their host galaxies and compare with predictions from feedback and outflow models. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2022-11-11T16:08:55.000 |
| 3399 | 2013.1.00352.S | 12 | Search for new sulfur-species formed in H2S-bearing, UV-photoprocessed ice mantles in circumstellar regions. | Sulfur is strongly depleted in dense clouds and circumstellar regions around YSOs. The missing sulfur might be locked onto the icy mantles of dust grains, initially in the form of H2S. Several S-bearing gas phase molecules such as H2S, SO2 or OCS have been observed in low-mass and high-mass hot cores, with abundances that cannot be explained with current gas-phase chemical models. Recent lab experiments have shown that energetic processing of H2S-bearing ices leads to efficient photolysis of H2S, with H2S2 and HS2 as the main products. We propose to observe several lines of H2S2 toward the hot corino around the IRAS16293-2422 low-mass protostar, where sulfur-bearing molecules are likely released by thermal or photo-desorption. These observations will confirm whether an important fraction of the missing sulfur is contained in H2S2 and HS2, and will provide key information about the poorly known chemical network of sulfur. | Astrochemistry | ISM and star formation | 2016-05-29T22:02:00.000 |
| 3400 | 2021.1.00899.S | 14 | A unique gas tracer of pebble drift in protoplanetary disks | In recent years, small pebbles (mm-cm sized grains) have been favored as the primary drivers of planetary growth, as pebbles are accreted by a growing protoplanet much more readily than kilometer-sized planetesimals. A key ingredient of current pebble accretion models is that a substantial amount of pebbles (20-400 earth masses) drift into the inner region over a few Myr. But it is still unknown whether such a large mass transport is possible in planet-forming disks. We propose to search for a characteristic signal of icy pebble drift in numerical simulations: a local enhancement of CO gas column density around the mid-plane CO snowline location. There are hints that such an enhanced CO gas column exists inside the CO snowlines of two well-characterized protoplanetary disks (HD 163296 and MWC 480). But existing C18O/C17O line observations are too optically thick inside 70 au to be conclusive. We propose to spatially resolve 13C18O (2-1) line emission in the two disks and search for a local enhancement of the CO gas column around their CO snowlines. These data will provide important constraints on current models of icy pebble growth and drift in disks. | Disks around low-mass stars | Disks and planet formation | 2023-08-29T15:24:25.000 |
| 3401 | 2012.1.00313.S | 0 | Search for debris disks in Class III | Single solar mass stars are all expected to form with a relatively massive circumstellar disk as a result of angular momentum conservation during collapse. Planetary systems are formed in these disks in the majority of systems, as indicated by exoplanets searches. Typical lifetimes of disks (~3 Myr) set the typical timescale for planet formation, however, even in the youngest star forming regions, the fraction of stars without a massive disk is significant. It is thus possible that, in some cases, planet formation and outer disk photoevaporation occur on much faster timescales (<1Myr) that currently envisaged. We propose to search for young debris disks, the remnants of this early planet formation process, in a sample of single diskless solar-mass young stars in the Ophiuchus and Chamaeleon I star forming regions. Our observations are designed to produce stringent limits on the possible existence of these debris disks and will be able to conclusively prove or disprove the hypothesis of early planet formation. | Disks around low-mass stars | Disks and planet formation | 2015-07-09T14:20:53.000 |
| 3402 | 2023.1.00424.S | 0 | Intermediate redshift ULIRGs: bridging the gap between starburst and main sequence galaxies | We propose to observe a representative sample of 30 ULIRGs at 0.3 < z <0.8 located between the main sequence (MS) and Starburst (SB) to study how the transition between these two modes of star formation occurs. The bimodality between MS and SB could be attributed to a larger molecular gas density or a more efficient mechanism that triggers star formation. The proposed sample of intermediate-z ULIRGs covers a representative parameter space in terms of luminosity, dust temperature, and redshift in the transition between star-forming galaxies and starbursts. Observations of the CO(2-1) transition at a resolution of ~1 kpc (0.11-0.22 arcsec) will allow us to characterise the dynamic state of the systems, study their kinematics and identify inflow/outflow features leading to a better understanding of the nature of these objects. The direct scientific aims of this proposal are to measure their molecular gas content and establish whether their Star Formation Efficiency is related to the disk/merger morphology and kinematics. These goals can only be achieved with ALMA resolution, allowing us to identify the interactions within these systems. | Starbursts, star formation | Active galaxies | 2024-12-08T13:10:51.000 |
| 3403 | 2016.A.00037.T | 39 | ALMA Monitoring of Sgr A* in July 2017 coordinated with Spitzer & Chandra Space Observatories | We propose to use ALMA as part of an observing campaign led by Spitzer and Chandra for continuous monitoring of Sgr A* for two days in July 2017. Recent detection of flare emission from Sgr A* at 4.5 microns using Spitzer gives a fantastic opportunity to monitor Sgr A* continuously. Spitzer monitoring of Sgr A* emission levels in the mid-IR is far superior to ground-based observations. Previous campaigns using mid-IR from the ground and space have never been able to monitor Sgr A* with such overlapping time coverage. The high sensitivities of the ALMA and the Spitzer provide a unique opportunity to confirm an absorption in submm wavelengths when there is a flare with a duty cycle of 55% occurring at mid-IR wavelengths, and to establish the relationship between submm and mid-IR flare emission. This will ultimately tell us about black hole accretion physics and will confirm that optically thin(mid-IR) and thick (submm) flare emission are physically associated with each other by a time delay between their peak emission or an absorption in submm when a mid-IR flare peaks. This experiment requires a long ALMA observation to be successful. | Galactic centres/nuclei | Active galaxies | 2018-05-03T19:18:37.000 |
| 3404 | 2016.1.01239.S | 86 | Aiming for completeness: the final Lupus disk demography | We propose to complete the Lupus disk demographic survey by observing the last 7 missing sources and quantifying their dust mass, gas mass and gas-to-dust ratio in a uniform manner with our previous surveys. Doing so will ensure we are not biased (by excluding outliers) and can select subsamples without fear of missing objects. We will observe C18O, 13CO in both J=3-2, J=2-1, CO J=2-1 and CN N=3-2 and use these lines to derive gas masses and probe the UV field. We will determine radial profiles for gas, dust, and gas-to-dust ratios. Our observations will also characterize the radial and azimuthal substructure of our targets, finding possible, as yet unseen, rings and cavities. These observations, complemented by our VLT optical-infrared spectroscopic survey and by Spitzer and Herschel infrared photometry, will leave a complete legacy to the community on this prime star-forming region. | Disks around low-mass stars | Disks and planet formation | 2018-07-07T02:13:28.000 |
| 3405 | 2021.1.00914.S | 10 | Ghost vs. Zombie Gas: Determining the Primordial vs. Secondary Origin of CO in Evolved Circumstellar Disks | The sensitivity of ALMA has revealed the presence of molecular, CO gas in three evolved disk sources. These are several Myr-old low-mass stars that appear to have lost their protoplanetary disks given their low IR and mm-dust emission. The origin of their CO gas is unclear. Is it lingering "ghost" primordial gas left over from the earlier protoplanetary disk stage? Or is it second-generation, revived "zombie" gas released via collisions and/or outgassing of volatile-rich planetesimals? These two scenarios present different expectations for the gas composition. Primordial gas would be H2-rich, similar to protoplanetary disk gas. In contrast, secondary gas would be dominated by H2O and CO, similar to comets. We aim distinguish between these two scenarios by searching for N2H+, as a tracer of its requisite precursor H2. We propose to observe the N2H+ J=3-2 transition in NO Lup, TWA 34, and TWA 7. Detections of N2H+ will reveal the presence of H2-rich, primordial gas whereas non-detections will favor the secondary gas scenario. The results of this analysis will provide valuable data regarding the dissipation timescale and planet-forming lifetime of protoplanetary disk gases. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2023-10-17T21:47:19.000 |
| 3406 | 2019.A.00034.S | 80 | Early Planet Formation in Embedded Disks (eDisk Survey) | We propose ALMA DDT observations toward 8 protostars from the ALMA eDisk Large Program that do not have contemporaneous observations at 0.2"-0.3" resolution scheduled as part of the accepted large program. We aim to ensure that the most crucial data for our program, 13CO, 12CO, and continuum are taken toward all our targets with the optimal integration time to enable joint analysis with the long-baseline data. The proposed observations will probe the region where the inner envelope transitions to the disk, and the proposed data are crucial for determining the outer radius of the gas disk (from 13CO) and dust disk (continuum). Moreover, the 12CO data are essential for characterizing the outflowing material near the disk. The DDT observations are necessary to ensure that the data quality and results of our ALMA large program are not compromised due to the shortcomings that were discovered in the archival datasets that we originally planned to use. This DDT program will significantly improve the legacy data quality and science output from the eDisk survey for less than 10% of the total time of the accepted large program. | Low-mass star formation | ISM and star formation | 2023-01-10T00:00:00.000 |
| 3407 | 2022.1.01399.S | 61 | Unveiling the Core Mass Function and mass segregation properties of star-forming clusters | Most stars form in clusters deeply embedded in molecular clouds, which fragment into dense cores of different masses. Knowledge on the core mass function (CMF), its evolution with time, and its connection to the final properties of the stellar cluster, are critical to understand star cluster formation. During the last years, ALMA has provided an unseen level of detail in the study of the CMF and cluster properties. However, observational limitations and biases on the spatial resolution and the accuracy of core mass determination may have affected the results obtained so far. With this proposal, we seek to overcome known observational biases and perform a detailed study of the CMF and cluster properties of four embedded clusters at different evolutionary stages, emerging from the same molecular cloud. Our proposed ALMA band 6 observations, with 200 au resolution and 0.1 Msun sensitivity, will allow us to resolve all the members in the cluster and probe the CMF from low to high core masses. This project will produce high resolution and sensitivity images with an important legacy value that will constitute an ideal test set for the different star cluster formation models. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2024-01-26T09:58:48.000 |
| 3408 | 2017.1.00341.S | 148 | An ALMA Survey of Lensed SMGs in the Hubble Frontier Fields | Gravitational lensing of massive galaxy clusters is a powerful tool to probe faint and high-redshift sources at all wavelengths. We propose an ALMA band 7 survey of an uniformly selected sample of 62 submm sources detected by JCMT/SCUBA-2 within the HST footprints of four Frontier Fields, A370, MACSJ0416, MACSJ0717, and MACSJ1149. Based on the lens models provided by the HST Frontier Fields community, our sample has a median intrinsic flux of ~ 1 mJy at 850 micron, corresponding to a SFR of ~ 100 M_sun/yr. This program will bridge the SFR gap between the dusty, submm population and the extinction-corrected UV-selected galaxies. These two populations are essentially disjoint with current samples of submm galaxies. The submm flux regime of our sample allows us to determine the critical SFR below which UV-selected galaxies alone account for all the star formation. ALMA observations will determine the optical/NIR counterparts to our submm sources. With the rich multi-wavelength data of the Frontier Fields, we will tightly constrain the properties of the ALMA-detected sources. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2020-10-31T13:01:49.000 |
| 3409 | 2022.1.00734.S | 10 | Closing-up into the birth of a planetary nebula | Planetary nebulae (PNe) are the final fate of stars like the sun. The study of objects making the transition into the PN is key to understand the subsequent evolution of these objects. IRAS 15103-5754 could be just entering the PN phase, and thus, a key object to understand the shaping of PNe. It exhibits outstanding observational features that indicates it could be the youngest PN known. Previous ALMA observations show that mm emission is dominated by free-free processes in ionized gas. A compact, elongated source, aligned with the CO outflow has been identified We aim at observing this source with the highest angular resolution available at bands 6 and 7 (20-15 mas). Our main goals are: 1- Confirm whether this compact region traces ionized gas. 2- Determine whether the source is a pristine photonionized region or an ionized jet. In the case #1, we would be witnessing in real time the formation of a PN. In the case #2, energetic ejections related to common envelope evolution should last as long as the PN phase. This project requires only 1.3h observing a singular object, caught in a key evolutionary stage, so we expect a high scientific return with a very modest integration | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-08-03T17:00:42.000 |
| 3410 | 2022.1.01411.S | 153 | Inheritance or reset? Probing accretion shocks with SO and SO2 | Is the gas and ice composition in the planet(esimal) formation zone of disks largely inherited from the pre-stellar core or has it been reset? One of the biggest uncertainties in answering this question is knowing whether or not the material undergoes a strong accretion shock as it enters the disk. High-resolution (~20-30 AU) ALMA images can potentially trace this shock and distinguish it from disk winds or jets/outflows through observations of suitable molecular tracers. SO and SO2 are two particularly well-suited molecules since their emission has been observed to originate at the disk-envelope interface and they are known shock tracers. We here propose to image both molecules in multiple lines (to constrain excitation) using a single ALMA Band 6 setting at much higher spatial resolution (~0.15") than done previously for the case of SO, to search for evidence of accretion shocks that reset the gas and ice chemistry. Combination with approved VLT-MUSE and JWST-MIRI data will help to further pin down the physical and chemical processing at the envelope-disk-outflow interface. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-10-25T20:44:38.000 |
| 3411 | 2017.1.00895.S | 18 | A Twin Paradox: NGC 253 and the Galactic Center | With Cycle 3 ALMA, we have made the first 2 pc scale maps of dense gas emission in Band 7 in NGC 253,the nearest galaxy with a central starburst. They reveal more than a dozen compact clouds, all located in a ~100 pc-radius ring of dense gas: surprisingly similar to the structure of the center of our own Galaxy, despite its order of magnitude lower mass and star formation rate. Why does the ISM in these sources appear so similar? We propose to measure gas excitation that will allow us to probe differences in chemical abundances and physical conditions that correlate with the star-forming states of these two systems. To do so, we will obtain comparable resolution (2.6 pc) observations of Band 3 tracers in NGC 253, including key optically-thin isotopologues, which can be directly compared to identical resolution (1.5-2.5 pc) observations of the Milky Way center in the same 3 mm tracers. By doubling our sample of galaxy nuclei resolved at these spatial scales, we will be able to provide key tests of models for the cyclical evolution of starbursts and winds in galaxy centers, and constrain the ISM conditions that drive these different global star formation rates and efficiencies. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2019-04-24T22:09:00.000 |
| 3412 | 2019.1.01094.S | 16 | Exploring the Exosphere of Europa | Jupiter's moon Europa is a high priority target in the search for life outside Earth, but direct investigations of the subsurface ocean are hindered by an exterior ice shell. While the surface and atmospheric compositions are intimately connected through sputtering, sublimation and freezeout, Europa's recently-identified atmospheric plumes provide a potential bridge between the atmosphere and ocean. We propose to detect and map H2O gas (in addition to SO2, HCN and H2CO), for the first time on Europa, as a probe of the exosphere and plume properties. Constraining the baseline atmospheric H2O density will (1) provide crucial information to assist in flyby planning for the upcoming JUICE mission, and (2) place rigorous constraints on Europa's surface ice properties and sputtering yields - in particular, the interactions between solid H2O and heavy ions and electrons from Jupiter's magnetosphere. The detection of spatially isolated molecular plumes would revolutionize our understanding of physical and chemical interactions between ocean, crust and surface on Europa and other icy worlds, opening up a new avenue of research into subsurface ocean composition and habitability. | Exo-planets | Disks and planet formation | 2023-06-09T00:00:00.000 |
| 3413 | 2012.1.01012.S | 0 | Characterising the dust radial segregation in the TW Hydrae protoplanetary disk | We propose to observe the well-known T Tauri star TW Hydrae in Band 3 continuum to provide the first direct measurement of dust radial migration in a disk for a single source. Comparison of SMA (870microns) and ATCA (7mm) observations of the protoplanetary disk around TW Hydra strongly suggests that the larger dust grains (> cm) are concentrated in the inner parts of the disk. ALMA offers a unique opportunity to characterise the details of the mechanisms at play: grain growth and radial migration. We propose to map the continuum emission in Band 3 (2.6mm), intermediate between 870microns and 7mm, and to do so at the same spatial scales as the SMA and ATCA data. With less than 1 hour of total observation time, we will map accurately the spatial distribution of millimeter grains, providing the first quantitative constraints on dust growth and kinematics in protoplanetary disks. These results are expected to provide very significant quantitative constraints on the dust evolution models in disks. | Disks around low-mass stars | Disks and planet formation | 2015-07-17T19:46:29.000 |
| 3414 | 2012.1.00596.S | 5 | ALMA Imaging of the Star Formation Process at the Historic Peak | ABSTRACT NOTE: This is a resubmission of an approved (top 10%) Band 9, Cycle 0 proposal, that has not yet been observed due to unusually poor weather conditions. The weather is improving, and more Band 9 data is expected soon. However the inexperience of a new instrument and calibration strategies at Band 9 make us pessimistic about the data in this Cycle. With Cycle 1, the calibration of the instrument and observing strategy are expected to be better understood. Also with 32 antennas, the gain calibration should also be a lot easier than in Cycle 0. Note also that we have added one source (SDP 11) to our observing program. If our Cycle 0 observations are completed, we will retract all redundant observations, as they are completed, perhaps just leaving SDP 11 in this program. We propose an ALMA "mini-survey" of z~2 sources to image the 158 µm [CII] line in five representative sources from our ZEUS/CSO survey. Through ZEUS/CSO spectroscopy we have detected the [CII] line from 24 star forming and AGN dominated galaxies in the z~1-2 redshift interval. The redshift range 1-3 is important since half the star formation through cosmic time occurred in this epoch. The [CII] line is a critical tracer of star formation, and we use this line together with the FIR continuum and CO lines to constrain the intensity and physical size of star formation regions. We find that star formation dominated sources host kpc-scale star formation regions with surface intensities similar to that of local starburst galaxies. This suggests a more quiescent mode of star formation in this epoch than the extremely intense and temporally punctuated starbursts powering similarly luminous local ULIRGs. We also find relatively weak [CII] emission in AGN dominated systems and evidence for [CII] line emission from the AGN-associated XDR in at least one system. Our ALMA source list samples a variety of environments capable of emitting strong [CII] line radiation that includes the blazar/AGN (PKS0215), an AGN host at the center of a proto-cluster of SMGs (RXJ0941) and one of the star forming SMGs within the cluster, the extreme luminosity (lensed) star forming galaxy SDP 11, and a transitioning starburst/QSO (SDSSJ1000). By constraining the origins and spatial distribution of the [CII] line we will trace star formation modes and efficiency. The proposed work is unique since it leverages the prior ZEUS/CSO detections of redshift 2 sources and, with the current ALMA configuration, the (Band 9) redshift 2 epoch is the only time within the z = 1-3 historic peak of star formation in which the [CII] line can be observed. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2016-10-22T18:44:25.000 |
| 3415 | 2017.1.00200.S | 278 | REsolved ALMA Survey Of Nearby Stars (REASONS): a population study of the formation location of planetesimal belts | Locating planetesimal belts is fundamental to understand their formation and evolution. We propose REASONS (REsolved ALMA Survey of Nearby Stars) to accurately measure the radius and geometry for 18 nearby planetesimal belts, completing the mm-flux-limited sample of the SONS JCMT Legacy Survey. We will study our newly discovered tentative correlation between belt radius and stellar luminosity, which already suggests a link to the CO snow line location in progenitor protoplanetary disks. If confirmed at high significance through REASONS, this would provide strong evidence for a common belt formation mechanism. By putting together a complete sample of all mm-bright debris disks, we will also provide a crucial test of the population synthesis models that fit the observed population of IR excesses. Additionally, we will search for exocometary gas and compare resolved disks with scattered light images, to constrain the ice content of exocomets and link it back to the belt formation location. This community effort will provide a legacy of all mm-bright resolved debris disks, fundamental for our understanding of the formation and evolution of planetesimal belts, including our own. | Debris disks | Disks and planet formation | 2019-08-31T12:19:20.000 |
| 3416 | 2018.1.01868.S | 138 | Deuteration in warm dense gas regions | Deuterated chemistry is an important tool in star formation, still not fully understood. In particular the deuterium fractionation (Dfrac) in warm dense regions such as photon-dominated regions (PDRs). We have developed chemical models to explain the deuteration level in such regions and tested them with observations in the star-forming region MonR2. The chemical model was able to reproduce the observed Dfrac assuming that deuteration occurs via gas-phase reactions. Moreover, it revealed that Dfrac of some species can be used as a chemical clock. Our previous observational studies lacked information on the spatial distribution, and recent observations have shown hints of a possible Dfrac spatial gradient. This suggests different deuteration processes in PDRs depending on the chemical/physical properties. In this proposal we aim to perform a spatial study of Dfrac in multiple molecular species towards two nearby PDRs: MonR2 and GGD14 (a presumably younger PDR, located at the same distance of MonR2). This will allow us to better understand the processes leading the deuteration in warm dense regions and will provide better observational constraints for the chemical models. | High-mass star formation | ISM and star formation | 2019-12-28T21:28:35.000 |
| 3417 | 2018.1.01210.S | 77 | The Water Snowline in AS205 | The distribution of water in protoplanetary disks plays a key role in planet formation. The condensation of water beyond the snowline boosts the solid surface density and enhances the formation of planetesimals as well as the formation of giant planet cores and super-earths. In cycle-4 we may have made the first direct measurement of the water snowline around a young solar-mass star. The detected 321 GHz water line from AS205 N (~ 1 Msun) is consistent with emission from a rotating disk within ~ 2 AU. The emission line strength indicates that we are probing water well below the warm disk surface, from the deep water reservoir inside the snowline. The surprisingly small inferred snowline radius in this high accretion rate object may indicate that the disk midplane is a cool "dead zone" that does not participate in accretion. Here we propose to obtain a higher signal-to-noise measurement of the water emission in order to confirm the detection and to measure the location of the water snowline more precisely. The proposed observations are important for advancing our ability to measure and understand water snowlines in disks. | Disks around low-mass stars | Disks and planet formation | 2020-09-03T19:24:25.000 |
| 3418 | 2018.1.01239.S | 65 | Spatially resolving the innermost dust formation and wind acceleration zone of the AGB star W Hya | The interplay between the dust formation and the mass loss in AGB stars is not yet understood well. Our multi-epoch visible polarimetric imaging of the well-studied AGB star W Hya with VLT/SPHERE-ZIMPOL has successfully spatially resolved the clumpy clouds of large, transparent dust grains very close to the star, ~2 stellar radii, and their salient time variations. Furthermore, our SPHERE-ZIMPOL images in the Halpha line and IR interferometric data in the 2.3 micron CO lines taken with VLTI/AMBER reveal the coexistence of dust, shock-heated hot gas, and molecular gas within ~3 stellar radii. We propose ALMA observations of W Hya in the HCN (3-2) line at 266 GHz, a good tracer of shocks and gas kinematics. We aim at mapping the velocity field within ~4 stellar radii with a spatial resolution of 16 mas. Comparison of the observed velocity field with the images of the dust clouds enables us to directly examine whether or not the scattering of photons by large grains is driving mass loss as the current theory predicts. In addition, the ALMA data of the HCN line are important for improving our understanding of the non-equilibrium chemistry governed by the shocks. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2020-11-20T01:10:09.000 |
| 3419 | 2015.1.00258.S | 42 | The failure of galactic star formation relations on sub-galactic scales: A direct probe of the physics of star formation | This is a resubmission of our successful Cycle 2 project that mapped CO(1-0) emission over a quarter of the optical disk of the nearby flocculent spiral NGC300. The delivered 12m- & 7m-array data yielded a fantastic high spatial (23pc) and spectral (0.32km/s) resolution map that reveal 200 molecular clouds (MCs), making this one of the finest (extragalactic) MC samples. We apply a newly developed model - the uncertainty principle of star formation (SF) - that relates the scatter in resolved SF and gas tracers (i.e. the breakdown of the Kennicutt-Schmidt relation on small scales) to the evolutionary state of SF regions. The model derives the timescale of MC formation, the duration of SF, and efficiency of feedback - all critical parameters of galaxy evolution that are hotly debated. We also plan to smooth the data to lower resolution to calibrate the model for future ALMA observations of more distant galaxies, opening up a much wider range of environments. However, for our method to yield correct timescale measurements and to contrast our dataset to more distant galaxies, we need to have flux-complete observations, therefore we request the completion of the total power observations. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2017-12-06T22:20:49.000 |
| 3420 | 2015.1.01227.S | 3 | Imaging the ISM on 50pc scales in a lensed z=2.3 starburst galaxy | We propose Band 7 and 9 continuum imaging, and Band 3 CO(3-2) spectral line imaging in the strongly lensed z=2.3 star-forming galaxy, SMMJ21352-0102 ("The Cosmic Eyelash"). The strong, 37.5x gravitational lensing of this source by the foreground cluster, combined with the high angular resolution (~0.1") of extended configuration ALMA observations will allow us to probe the ISM on ~50pc scales, approaching the sizes of individual giant molecular clouds. Using the off-spectral line portion of our Band 3 observations, we will - at no additional cost of telescope time - create a high sensitivity 0.2" 3mm continuum image of the Eyelash. These observations will probe rest-frame 140, 260 and 1000 micron emission, allowing us to construct a spatially-resolved far-IR SED in this galaxy, measuring the star formation efficiency of GMC-scale gas clumps, and creating maps of dust mass and temperature. Together with existing JVLA CO(1-0) and C-band continuum observations at comparable resolution, we will study the spatially-resolved gas excitation and fuelling of star formation in this strongly-lensed, but otherwise "typical" high-redshift star-forming galaxy. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-05-31T17:58:36.000 |
| 3421 | 2016.1.00492.S | 17 | Molecules and Dust Near Embedded Star Clusters in He 2-10 | Super Star Clusters (SSCs) hold large concentrations of O stars and can have great impact on their host galaxies. Evolution is fast in SSCs; they can create huge amounts of metals, and thus of dust, in their first few million years. The dwarf starburst galaxy He 2-10 has created many massive young star clusters in a region ~150 pc across. Where is the dust in He 2-10? What is the Gas-to-Dust (GTD) or CO-to-dust ratio in this intense starburst, and does it vary across the star forming region? How do the dense CO clouds compare, in 3D, to the ionized gas? ALMA imaging of continuum at 850microns, along with CO(3-2) spectra, can address these questions. | Merging and interacting galaxies | Galaxy evolution | 2018-02-12T04:48:04.000 |
| 3422 | 2021.1.01034.S | 9 | Tracing Signatures of Infall onto Uranus | The proposed observations explore the connection of Uranus' atmosphere with its interior and environment. With ALMA Band 7, we will simultaneously measure the CO (3-2) and HCN (4-3) rotation lines at a spatial resolution of 0.28" and a sensitivity of 200mK. The CO vertical profile, derived from the observed line shape, will improve constraints on CO infall from the Uranian environment and tighten limits on the abundance of CO uplifted from the warm planetary interior. The latter is tied to bulk oxygen abundance, thereby revealing information about the formation of Uranus, and of ice giants more generally. We will also improve the detection limit of HCN by a factor of 10, and spatially map Uranus in both CO and HCN in order to test whether these gases are the product of comet impacts, or point to other candidate infall sources. Our observations will improve our understanding of impacts throughout the outer Solar System, which is likely underestimated from satellite cratering counts; and inform models of Solar System formation and evolution. | Solar system - Planetary atmospheres | Solar system | 2025-05-03T13:34:21.000 |
| 3423 | 2013.1.00210.S | 8 | Unveiling the building elements of nearest and youngest starburst galaxy NGC5253 | The nearest and youngest starburst galaxy, NGC 5253, is the most suitable target for understanding the intense massive star formation and their stellar feedback in a nuclear starburst system. We aim to unveil the molecular and ionized gas structure around the very young massive super stellar clusters (SSCs) known to co-exist in the central starburst in NGC5253. Monreal-Ibero et al. (2010) suggested a scenario that the outflow of the ionized gas from the central SSCs expels the ambient gas outwards and encounters with the quiescent gas shell, which is likely the site for formation of subsequent generation of stars. We have confirmed with our pilot SMA CO(2-1) observations that the molecular gas is associated with the central SSCs, but the spatial/velocity resolution is insufficient to verify their scenario. We propose to observe at 3pc resolution the CO(2-1) emission, which is a tracer of the parental molecular gas of the SSCs, and hydrogen recombination line (H30alpha) to study the structure of the ionized gas around those SSCs, and CS(5-4) for shocked dense gas by interaction between the expanding ionized gas and ambient gas. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2016-04-02T23:04:37.000 |
| 3424 | 2019.1.00251.S | 684 | Kuiper Belt Progenitors in the Pleiades | There are few observational constraints on debris disks around solar-type stars at radii >>10 AU at the critical ages near 100 Myr when planetary systems are dynamically active and evolutionary models suggest that collisional dust production peaks. These cold outer dust belts include systems like the progenitor of our Kuiper Belt. We propose ALMA dust continuum observations of a large sample of solar-type stars in the nearby 100 Myr old Pleiades cluster, to reveal cold debris disks and quantify their incidence and fractional dust luminosity. These observations (1) will provide sensitivity to cold dust belts at large radii missed by infrared surveys, enabling tests of debris disk evolutionary models in a new regime, and (2) will discover the most luminous cold debris disks in the Pleiades for follow-up imaging studies at higher angular resolution and sensitivity to further test the predictions of debris disk evolutionary models. | Debris disks | Disks and planet formation | 2021-04-17T15:22:42.000 |
| 3425 | 2016.1.00173.S | 7 | Polarimetric Imaging Observations of the Disk around TW Hya | Obtaining observational constraints of grain size is important in understanding planet formation. We propose to observe the disk around TW Hya in polarized emission in Band 7 in order to obtain direct constraints on grain size. Our near infrared polarized imaging observations have indicated that grain growth takes place in the disk. Most recently, Andrews et al. (2016) have found that the disk harbors several gaps and our ALMA Cycle 3 program has revealed that the dust opacity index increases at the location of one of the gaps, suggesting that the size segregation takes place. Recently, we have suggeted a method of constraining the grain size in the disk by using polarization observations. In the presence of radial structures such as gaps and/or bumps and with the dust particles grown to a certain size, dust continuum emission is expected to be polarized due to the scattering by the dust particles themselves. With its complex radial structures of dust continuum emission, TW Hya is one of the ideal targets that we expect to observe scattering-induced polarization and to be able to put constraints on grain growth. | Disks around low-mass stars | Disks and planet formation | 2019-11-28T18:11:33.000 |
| 3426 | 2019.1.01450.S | 30 | The molecular gas content of the host galaxies of Fast Radio Bursts | The inability to localize the radiation from fast radio bursts (FRBs) has been the key stumbling block to unravelling the origin of their enigmatic emission. Over the last few months, the Australia SKA Pathfinder (ASKAP) has obtained sub-arcsecond localization of three non-repeating FRBs, FRB180924, FRB181112 and FRB190102. Our optical imaging and spectroscopy have identified the FRB host galaxies, at z=0.3214, z=0.4755, and z=0.291, respectively. The 0.1-0.5'' accuracy of our radio positions presents an outstanding opportunity to directly examine the progenitor environments of a sample of FRBs and trace the conditions that give rise to the bursts. Mapping the CO emission from the FRB host would allow us to test from the CO velocity field whether the FRB arises from a cataclysmic event. As the first step towards this mapping, we request ALMA Band-6 time to observe the CO J=3-2 emission from the three FRB host galaxies to measure their molecular gas content and star formation efficiency. | Starbursts, star formation | Active galaxies | 2021-09-12T00:00:00.000 |
| 3427 | 2022.1.00602.S | 18 | Extended Dust Profile of z~2 Cluster-Lensed Submillimeter Galaxies (Completion) | As the most vigorously star-forming galaxies at z~2, submillimeter galaxies (SMGs) are generally found to host compact dust continuum with a half-light radius (Re) of 1~2 kpc. After rapidly depleting their gas within ~200 Myr, SMGs are believed to evolve towards compact quiescent galaxies. Previous ALMA observations have revealed a population of low-surface-brightness SMGs with extended dust profiles (Re up to 3.7"; ~7 kpc lensing corrected). These features are consistent with galaxies quenching from the inside out. To directly capture the star formation cessation and dust depletion/dispersal of these short-lived starbursts, we propose to observe 13 cluster-lensed SMGs with ACA in Band 7. Specifically, with the critical low-spatial-frequency uv-coverage of ACA, we will, (1) discover more SMGs with extended dust profiles, and (2) deliver the best statistics of stellar and dust properties in these z~2 SMGs in their final quenching stage. Combined with existing Herschel and Spitzer data, this multi-wavelength census will unambiguously reveal the disappearance of compact dust structures in the end stage of SMGs, building up the evolutionary picture for the most massive galaxies at z~2. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-03-06T19:35:05.000 |
| 3428 | 2011.0.00001.SV | 0 | Science verification observation of TW Hya | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Disks around low-mass stars, Astrochemistry | Disks and planet formation | 2016-06-24T14:02:06.000 |
| 3429 | 2013.1.00379.S | 10 | The Forgotten Local Ultra Luminous Infrared Galaxy: IRAS 13120-5453 | IRAS 13120-5453 is the second nearest (D = 137 Mpc) and the least studied Ultra Luminous Infrared Galaxy (ULIRG) with no published ground-based CO observations. We propose to use ALMA to observe IRAS 13120-5453 in several 12CO and 13CO lines. When compared to Arp 220, IRAS 13120-5453 has a similar far-infrared luminosity but optical images show that IRAS 13120-5453 is more compact with ordered structure in the form of spiral arms. We will use the proposed observations to study the distribution and physical conditions of the molecular gas and compare it to other local ULIRGs such as Arp 220 and Mrk 231. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2016-08-26T17:06:49.000 |
| 3430 | 2017.1.00232.S | 134 | The Surprising Molecular Content of Planetary Nebulae: A Closer Look at Chemistry, Dynamics, Structure and Evolution | We propose to image the J=2-1 line of CO toward five planetary nebulae (K3-45, K3-58, M1-7, M2-48, and M3-28) and the J=3-2 transitions of HCN and HCO+ toward three (M1-7, M2-48, and M3-28). We will resolve the distributions and kinematics of molecular gas on arcsecond (~ 0.005 pc) scales using nebulae of a variety of ages to show for the first time how the distributions evolve over the nebular lifespan prior to dispersing into the interstellar medium as diffuse molecular gas. Tracing the kinematic structure of the molecular outflows will allow a coupling of dynamical and chemical models that is needed to explain the surprising persistence of molecular gas in the presence of the intense nebular UV radiation. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-05-28T16:47:05.000 |
| 3431 | 2013.1.00722.S | 27 | A Full Inventory of the Molecular ISM in Two Starburst Galaxies at z=5.7 | We propose a full molecular line inventory in Bands 3 and 4 of the two highest known redshift dusty starburst galaxies accessible by ALMA, at z=5.7, close to the end of Cosmic reionization. A carefully-constructed tuning setup targets more than 40 lines of 13 molecular species expected to be detectable in these objects, tracing the full range of excitation conditions, heating mechanisms, outflow and dynamical signatures, and chemical enrichment pathways. At these rest frequencies, our observations will match and even exceed the sensitivity of local starbursts observed by Herschel/SPIRE. By exploiting high-resolution ALMA 870um continuum observations, low- and mid-J CO observations with ATCA and ALMA, [CII] emission from APEX, and full optical-to-radio SED coverage, these observations will stand as the definitive view of the ISM conditions in these objects, serving as an effective comparative study to local starbursts (e.g. Arp220) and intermediate-redshift analog systems (e.g. the Eyelash). In one target, we aim to spatially resolve the molecular line emission, allowing a 1 kpc-scale study of the near-Eddington-limited star formation underway in this object. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-07-03T00:21:11.000 |
| 3432 | 2011.0.00001.E | 0 | Proof of Concept of Response to Targets of Opportunity: GRB 110715A followup Band 7: continuum | ALMA engineering data release. | 2018-07-10T12:50:52.000 | ||
| 3433 | 2023.1.00885.S | 0 | Chasing Giants: Discovering a Large Population of z > 3 Massive Quiescent Galaxies with ALMA | We do not know how massive quiescent galaxies grow their incredible mass then rapidly quench over short timescales in the first 2 Gyr of the cosmos. Large samples (>100) of massive quiescent galaxies at z > 3 are desperately needed to solve these evolutionary puzzles with statistical confidence. Due to their rarity, only wide-field surveys (> 100 sq. arcmin) can provide such sample sizes, but quiescent galaxy selection techniques are contaminated by dusty galaxy populations. We request a total of 29 hours of Band 7 continuum imaging to filter 614 quiescent galaxy candidates at z > 3 identified via their JWST colors in the COSMOS-Web and PRIMER-COSMOS surveys. We will generate a legacy sample of z > 3 quiescent galaxies that is >2x larger than any sample to date to: (i) directly measure the volume density of 3 < z < 5 quiescent galaxies, and (ii) measure their spatially resolved stellar properties. Both goals are critical to test theories on high-z massive galaxy growth and quenching. This proposal will also unveil a large sample of moderately IR luminous (~ 10^12 Lsun) galaxies -- a population that may link z > 3 quiescent galaxies with dust-poor massive galaxies at z > 6. | Surveys of galaxies | Galaxy evolution | 2025-10-09T15:56:38.000 |
| 3434 | 2015.1.00299.S | 10 | Mapping the feedback effects on the gas reservoir in a z~1.6 QSO | We have recently reported, based on X-shooter and SINFONI data, the best example of a 10-kpc scale AGN-driven ionised outflow in the z=1.6 obscured QSO XID2028, showing effects of feedback in the host galaxy. For this object we have also evidence of atypically low gas fraction from PdBI data, consistent with a scenario where the gas has been already affected by the effects of the strong QSO feedback. Therefore, this source is the best suited for deep ALMA follow-up observations at a resolution comparable with SINFONI data (0.4", few kpc in size). With a total of 6.5 hrs of observing time this program: 1) will provide the first, unambiguous observational detection of AGN feedback affecting the gas reservoir of a z~1.5 QSO host galaxy; 2) may provide the first detection of a molecular outflow in the CO transition in a z>1 system. Overall, the observations will maximize the scientific return of ALMA Early Science spatial and spectral capabilities and will provide the missing 'smoking gun' of AGN feedback in action at the peak of AGN/galaxy formation, thus resulting in a crucial step for both theoretical and observational studies of galaxy evolution. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-08-08T18:15:59.000 |
| 3435 | 2023.1.01243.V | 0 | Exploration of the Black Hole Spacetime of Sgr A*: Dynamics and Achromaticity in the Black Hole Shadow | The EHT has recently released the first horizon-scale images of the Galactic Center supermassive black hole, Sgr A*, whose black-hole shadow has the largest angular size of any black hole in the universe. Accurate measurements of the emission near the black hole allow us to test general relativity, assess the magnetic field, and explore the co-evolution of the host galaxy.The restored images and time-domain sampling of Sgr A* represent one of the most promising projects for addressing these challenges. We propose 31.5 hours observing Sgr A* with ALMA+EHT leveraging the improved (u,v)-coverage and mitigation of the scattering with frequencies at 230, 260 (Band 6), and 345 GHz (Band 7). The proposed observation will enable us to: 1) significantly improve the fidelity of horizon-scale Sgr A* images with observational advantages; 2) resolve the detailed magnetic field structure and probe the existence of the jet, if it exists; 3) understand the origins of near-horizon plasma variability directly recovering the dynamic motions; and 4) provide an independent test of the scale-invariance of the black hole spacetime with tighter constraints. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 3436 | 2013.1.00115.S | 27 | Molecular gas properties and Fundamental Plane Relations in SDSS-selected Isolated Galaxies | We aim to unveil the molecular gas properties of galaxies evolving secularly, in an equilibrium between gas inflow, outflow and star formation. We will investigate the fundamental relations between molecular gas, atomic gas, stellar mass, star formation rate, and metallicity, with minimized contamination due to the effect of the environment, and emphasizing the poorly studied range of low stellar masses (log(M_*[Msun])<10.0) and low star formation rates (log(SFR[Msun/yr])<0.5) which characterize the vast majority of isolated late type spirals. The sample we have chosen is composed of 50 nearby galaxies proven to be isolated based on SDSS DR9 photometric and spectroscopic information, and covering the parameter space of this population of isolated spirals. The modest request of observing time (10 hours) in band 3 will also allow us, for the first time, to study the distribution and kinematics of the bulk of the molecular gas using CO J=1-0 emission, with resolutions <750 pc, and surface density sensitivities Sigma_gas ~ 20 Msun pc-2. This will allow us to investigate the link between the molecular gas distribution and the location of each galaxy in the fundamental relations. | Spiral galaxies | Local Universe | 2016-10-19T11:09:41.000 |
| 3437 | 2011.0.00182.S | 0 | ALMA Exploration of Nuclear Regions of Nearby LIRGs -- Warm Molecular Gas Distribution Down to 100 pc | We propose to obtain, using ALMA in both extended and compact configurations, high angular resolution and high imaging quality maps of the CO J=6-5 line emission (rest-frame 691.473 GHz) and the 450 micron continuum of two nearby luminous infrared galaxies (LIRGs; having LIR>10^11 Lsun): NGC34 (Sy2, D=84 Mpc, 1''=407 pc) and NGC1614 (starburst, D=68 Mpc, 1''=331 pc). These observations will exploit the best angular resolution (0.23") that ALMA can achieve in its shortest wavelength band (Band-9) available for the Early Science Call, and will resolve for the first time distributions of warm molecular gas (T>50K) and sub-millimeter dust radiation in LIRGs with spatial resolutions better than 100 pc. NGC34 and NGC1614 have recently been observed by Herschel SPIRE Fourier Transform Spectrometer (FTS) for the CO spectral line energy distribution (SLED) from J=4-3 to J=13-12. Among 125 LIRGs in the Great Observatories All-sky LIRG Survey (GOALS) that are being observed by Herschel, they are (1) the closest, (2) the brightest in CO(6-5) line flux, (3) with the best Band-9 transmission during the transit, and (4) showing strong nuclear activity. The high spatial and velocity resolutions of our proposed ALMA observations (5.02 hr in total) are crucial in distinguishing different nuclear gas configurations, e.g., outflow or inclined circum-nuclear disks. The ALMA data will allow us to address such important questions as: (i) Is the outflow strong enough to power the warm CO emission now and quench the star formation in future in both LIRGs (one starburst and one AGN)? (ii) Can the hard X-ray irradiation dominate the excitation of the warm CO around an AGN? And how large are the X-ray dominated regions (XDRs)? | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG), Outflows, jets and ionized winds | Galaxy evolution | 2013-10-31T15:28:00.000 |
| 3438 | 2021.1.01616.L | 481 | ALMA JELLY - Survey of Nearby Jellyfish and Ram Pressure Stripped Galaxies | We propose the first ever statistical survey of the molecular component of ram pressure stripped (RPS) galaxies with extended multiphase and star forming (SF) tails. This will constitute the first systematic and homogeneous sample of a large number (28) of molecular RPS galaxies in the nearby massive, high-pressure clusters Coma, Leo and Norma (z<0.025). The sample is representative in its variety of different stages of stripping (from early with tails connected to SF disks, to late with detached tails and passive or post-starburst disks), stellar masses, star formation rates, projected locations in the clusters, tail geometries, as well as intracluster densities and temperatures. At 1 arcsec resolution, we will map CO(2-1) emission and learn about the incidence, origin and evolution of stripped molecular gas, measure the star formation efficiency at sub-kpc scales, and from comparison with other wavelengths, study the evolution of the multiphase stripped gas. Studying in a variety of galaxies and environments the molecular component that is likely a major source of stripped material is crucial for understanding the evolution of the host galaxies. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2023-06-04T20:03:07.000 |
| 3439 | 2019.1.01615.S | 94 | Resolving the molecular and atomic gas content of galaxies beyond the local Universe | This proposal is a resubmission of 2018.1.01852.S We propose to complete the imaging of molecular gas and dust in the remaining 7 of 14 galaxies at 0.11 | Surveys of galaxies | Galaxy evolution | 2021-06-10T19:07:57.000 |
| 3440 | 2019.1.00905.S | 16 | The unique ram pressure stripped tail of the Coma galaxy D100 | D100 is a ram pressure stripped galaxy in the Coma cluster, with one of the longest and narrowest (60 x 1.5 kpc) rps tails of gas ever observed. The narrow tail originates from late stage stripping, which is very rarely observed, because gas at the center of the galaxy is generally too strongly bound to strip. One reason why we see gas being stripped from D100 could be due to the starburst in the circumnuclear region; a starburst outflow would push gas, both atomic and molecular, out and make it easier to strip. Our proposed ALMA observations would confirm the presence of a starburst outflow. Furthermore, we have discovered significant amounts of molecular gas in the tail with the IRAM 30m antenna in 22'' beams, and star formation occurring throughout the tail with HST. The efficiency of star formation is the lowest ever observed for a rps tail. The proposed ALMA observations would reveal the structure and concentration of molecular gas around identified star forming regions, which would us investigate why the SFE is so low. Kinematic and morphological study of the molecular gas would also tell us how the gas evolves as it is added to the intercluster medium. | Starbursts, star formation | Active galaxies | 2022-08-17T15:45:29.000 |
| 3441 | 2018.1.01458.S | 152 | New method to dynamically determine stellar mass of young stars | We developed a new method to dynamically determine stellar masses of young stars by maximizing the autocorrelation between molecular-line data cube of their surrounding disks and various Keplerian rotational patterns. We have applied this method to the ALMA data of 13CO (3-2) of the young stars in Lupus. We successfully obtained 16 measurements of dynamical stellar masses. Our measured dynamical masses are consistent with the spectroscopically determined stellar masses within the 1-2 sigma uncertainties. In the current 13CO data, the on-source integration time is only 1 minute per source. With this limited integration time, we achieved an accuracy of 30%-50% in dynamical mass with our new method. However, this accuracy is not sufficiently high to calibrate stellar evolutionary models used in the spectroscopic method, which has a typical uncertainty of 10-20%. Thus, we propose ALMA observations of 25 stars with 5-10 minute integration per source to improve the accuracy of our dynamical mass determination by a factor of 2 to 3. Thus, we will make a statistically significant comparison between the two determinations and potentially even calibrate stellar evolutionary models. | Disks around low-mass stars | Disks and planet formation | 2020-11-19T20:05:16.000 |
| 3442 | 2023.1.00802.S | 10 | Deep Dive into the ISM at z=6 with ALMA + JWST: From the Individual Lensed Star to 1-20pc Star-Forming Clumps | Recent HST and JWST/NIRCam studies have identified strongly lensed star clusters and even individual stars out to z=6, offering us new hope of directly observing such compact systems and their local environments at cosmological distances. Here we propose ALMA [CII]158um observations of the most highly magnified (mu~300) low-mass dwarf galaxy (2e9 Msun) hosting the strongly lensed star, Earendel (Welch+22, Nature), whose redshift has been confirmed at z=5.93 in the latest JWST/NIRSpec observations. In the 16" long lensed arc, the recent NIRCam observations also map out diffuse ISM gas as well as several compact clumps that are the most distant known bound massive star clusters, with radii between 1 and 20pc, the size of local star clusters. This program aims to complete the initial FIR characterization from the full (~16") lensed arc to the individual small clumps by obtaining their total fluxes and distributions of the [CII] emission line and the dust continuum via the combination of the compact and extended configurations. This is an essential step to design future further high-resolution follow-up to study e.g., even the rotation of the individual star clusters at z=6. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2025-09-24T18:30:52.000 |
| 3443 | 2015.1.01265.S | 8 | Study of the Interstellar Medium in the Most Luminous Starburst Quasar Host Galaxy at the Reionization Era | We propose observations of the [O I]145 micron, [N II]122 micron, CO(9-8), and (8-7) line emission and a study of the physical conditions of the interstellar medium (ISM) in the most millimeter luminous quasar, J2310+1855 at z=6.003. This object is the brightest dust continuum, CO(6-5), and [CII]line source in our millimeter survey of high-z quasars. The detections suggest intense star formation in the quasar host galaxy while the optical/NIR observations reveal a luminous AGN with broad absorption line features. Thus, this object provides a unique laboratory and an outstanding example for detailed studies of the ISM in the first quasar-starburst systems. At z~6, a full set of fine structure lines, as well as the high-J CO transitions from the AGN-heated molecular gas (J>7), are well covered by the spectral windows of ALMA. These lines trace different phases of the ISM (molecular, neutral, and ionized). The observations we request here will probe the density, temperature, radiation field and metallicity of the warm and cold ISM, and address how star formation and AGN activities contribute to the heating and excitation of the ISM in the nuclear region. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-11-15T16:21:26.000 |
| 3444 | 2013.1.01255.S | 1 | Probing Cool Dust in the Type Ia Supernova Remnant 0509-67.5 | In this proposal, we aim to detect thermal continuum emission from cool Fe grains that were formed in the innermost ejecta of Type Ia supernova remnant (SNR) 0509-67.5 in Large Magellanic Cloud. The goals of this proposal are (1) to obtain the millimeter images of the central diffuse region of SNR 0509-67.5 in Bands 7 and 6, and (2) to measure accurately the thermal emission fluxes from dust grains in the central region. For Fe grains with the mass of 0.1 Msun and the temperature of 30 K, the expected fluxes are higher than 0.18 mJy in Band 7 and 0.07 mJy in Band 6. The proposed observing time is 6.1 hours in total, which enables us to detect Fe grains of 0.1 Msun with 5 sigma confidence both in Band 7 and Band 6. Because this sensitivity is based on a conservative estimate, it is highly possible to detect cool Fe grains in SNR 0509-67.5. By determining the mass and typical radius of Fe grains from the measured fluxes, we will solve a long-standing problem whether Type Ia supernovae are sources of Fe grains in the Universe or not, and provide insights into the origin and evolution of interstellar dust, as well as the dependence of dust formation process on the type of supernovae. | Supernovae (SN) ejecta | Stars and stellar evolution | 2016-06-03T10:52:55.000 |
| 3445 | 2017.1.01195.S | 43 | The first detection of the [OIII]88um from Two QSO host galaxies in the reionization epoch | To understand the coevolution of blackholes and host galaxies, it is crucial to investigate properties of QSO host galaxies at the reionization epoch (z>=6). Here we propose ALMA Band8 observations of two QSO host galaxies at z=6.0, SDSS J2310+1855 and SDSS J054-0005, targeting the [OIII]88um line and dust continuum emission. The objects have the highest [CII]158um line luminosities among QSO host galaxies at z>=6.0, making them the best targets for follow-up observations of [OIII]. We aim the first [OIII] line detections from QSO host galaxies at the reionization epoch. With the line ratios of [OIII]/[CII], we examine ionization parameters of host galaxies. In addition, our dust continuum data will allow us to place strong constraints on dust temperature and on dust masses. Our proposal will allow us to perform systematic comparisons of ionization parameters and dust properties between QSO host galaxies and star-forming galaxies at the reionization epoch, highlighting the difference or similarity between the two galaxy populations. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-07-30T16:33:01.000 |
| 3446 | 2012.1.00261.S | 0 | Low luminosity millimeter survey behind strong lensing clusters v2 | We propose to perform 1.3 mm (Band 6) observations covering the line and continuum emission of highly-amplified (x > 10) galaxies behind the massive clusters Abell 1689 and Bullet. We can cover a survey area of 6 arcmin2 down to an intrinsic (lensing-corrected) sensitivity of 0.05 mJy (4sigma), corresponding to a detection limit of 10^9 Lsol at z=2.5! We expect to detect ~ 18 low luminosity continuum sources at 11. We will compare their properties to those derived for more strongly star forming UV/submm-selected galaxies at these epochs to trace out the variation in dust content and reddening with SFR at z>1. These observations will begin to delineate the information about the majority population of low luminosity, high-redshift galaxies which ALMA will deliver in full operation | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2015-05-26T13:38:44.000 |
| 3447 | 2022.1.00678.S | 17 | Breaking the Degeneracy - Robustly constraining dust temperatures in z~5 galaxies with Band 9 observations | Measuring the evolution of the dust temperature (Tdust) in star-forming galaxies is key to understanding how their dust, interstellar medium, and obscured star formation properties changed across cosmic time. While dust temperatures of nearby and moderately high-z galaxies are well constrained, at z > 4 we are still limited to Tdust values based on stacks of galaxies (which are hard to interpret), or from single sources with dust spectral energy distributions (SED) that do not detect the peak - the most sensitive part of the SED to changes in Tdust. Our goal is to detect for the first time the peak of the dust SED in two main-sequence galaxies at z~5 using Band 9. These targets already have the rising portion of the SED detected from Bands 6, 7 and 8. Our proposed Band 9 observations will add the key missing point required to obtain robust dust temperatures, which will translate into reliable measurements of the infrared luminosity, obscured star formation activity, and dust properties of normal star-forming galaxies at z~5 - all fundamental in the context of galaxy evolution. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-02-22T16:54:13.000 |
| 3448 | 2023.1.00063.S | 0 | Gas fractions of Early Type Galaxies at z=0.3 from the MAGPI survey | We propose to observe CO(1-0) in 53 galaxies located in 3 group/cluster environments from the 300 hr VLT/MUSE large program MAGPI. This program will be the first ever measuring gas fractions of early type galaxies at z=0.3, we will also determine the link between the basic gas properties of molecular gas in a rich group in a period in which groups experience significant evolution. The gas fractions of early type galaxies change by order of magitude between redshifts 0.7 and 0, our observations will offer a critical linchpin in constraining when in the history of the Universe this drop occured. These observations are supported by deep optical spectra and an in-depth simulation suite that includes mock observations from EAGLE, Illustris, Magneticum, and Horizon-AGN. The MAGPI data will facilitiate kinematic and stellar population studies that can compare angular momentum, absorption diagnostics to the presence or absence of gas. | Early-type galaxies, Galaxy groups and clusters | Galaxy evolution | 2025-10-25T11:44:07.000 |
| 3449 | 2023.1.01668.S | 0 | One-percent precision measurement of the Sunyaev-Zel'dovich Effect | We propose Band 1 observations of the Sunyaev-Zel'dovich effect (SZE) toward RXJ1347.5-1145 at z=0.451. The proposal is designed to achieve, for the first time, the peak signal-to-ratio reaching 100 and the spatial resolution of 10 arcsec. This will provide unique probe of unexplored physics of galaxy clusters, such as the equation of state of gas perturbations and the spectra of radio halos at the highest frequency ever reached. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2025-04-22T08:20:02.000 |
| 3450 | 2021.1.00409.S | 24 | Systematic search of H2O emission in quasar host galaxies at z>6 | Quasars beyond redshift z~6 are the most luminous and active sources when the Universe was less than 1 Gyr old. Their extreme luminosities and the intense star formation in their host galaxies make these objects an ideal laboratory to characterize the interstellar medium (ISM) at the dawn of cosmic time. While traditional tracers of the cold (T<100 K) interstellar medium, such as [CII] (and CO), have now been reported in about 50 quasars at z>6, very little is known about the warm, dense phase of the molecular medium that is associated with shocks and outflows. This phase can be studied via water vapor emission, but so far only sporadic detections have been reported at z>6. Here we propose to systematically sample a suite of key diagnostic water transitions (along with CO lines for free) spanning a wide range of energies in four IR-bright quasars at z>6. This study will enable a first quantitative analysis of the H2O emission and will provide us with a temperature measurement of the warm molecular medium for the first time in quasars at cosmic dawn. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-10-23T18:52:43.000 |
| 3451 | 2023.1.01558.S | 0 | Measuring 12C/13C with C18O and 13C18O in the Galactic outer disk | The 12C/13C and 16O/18O abundance ratios provide rich information on physical processes regulating the evolution of stars and galaxies. The Galactic carbon and oxygen isotope gradients are essential to constrain chemical evolution models of the Milky Way and various stellar yield models. However, these isotope ratios are poorly constrained at Galactocentric radii beyond 12 kpc. The only 12C/13C ratio measured at 15 kpc radius was proven as a false detection recently. Therefore, new measurements at Galactocentric radii > 12 kpc are urgently needed. Using C18O/13C18O to derive 12C/13C can overcome the drawbacks of deriving 12C/13C using absorptions lines or CN with optical depth correction. From the literature, we select four strong CO clouds at Galactic radii between 12 and 16 kpc and plan to observe 13CO 1-0, C18O 1-0, C17O 1-0, and 13C18O 1-0, to derive 12C/13C and 16O/18O/17O, respectively. The applied observations will not only put strong constraints on the Galactic chemical evolution in the outer disk but also help provide chances to test possible diversions between 12C/13C from different tracers. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-03-19T15:34:54.000 |
| 3452 | 2024.1.01015.S | 0 | Revealing Exotic Gas to Dust Ratios in Quiescent Galaxies | This ACA-only project will test theoretical predictions that dust is depleted more rapidly than molecular gas in quiescent galaxies, providing new empirical constraints on models of galaxy quenching. We will measure band 7 continuum emission from 28 galaxies and use this data to estimate dust masses, which we will compare to gas masses derived from existing CO spectral line observations. Given the existing gas measurements and simple hypothesis to be tested, the scientific return of our project is highly secure - we will either detect continuum emission from our quiescent sources or set lower limits on the gas-to-dust mass ratio of 500 in un-detected sources. The latter scenario will strongly rule out star forming galaxy-like gas-to-dust ratios in our quiescent sample, confirming theoretical predictions, while the former will require refinement of models of the ISM in quenched and quiescent galaxies. Either result will provide new insight into the residual cold ISM in galaxies below the star forming main sequence, refining our understanding of this critical phase of galaxy evolution. | Surveys of galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 3453 | 2016.1.00182.S | 1 | A Study of Solar Spicules at Millimeter, Optical, UV, and EUV Wavelengths | Solar spicules are ubiquitous, dynamic, filamentary jets extending several thousand kilometers into the solar atmosphere with temperatures of ~10^4 K. Despite decades of study, their origin, properties, and role in the energetics and mass budget of the solar chromosphere and corona have been uncertain. It has been only recently that their observational characteristics have been established with some confidence, thanks to several space-based missions launched in the past decade. These observations of spicules have provoked intense interest, leading to proposals that certain spicules play a central role as a source of hot plasma in the solar corona. We propose here to use ALMA in an exploratory program to characterize statistically the thermodynamic properties of spicules at the solar limb by measuring the ensemble of heights above the limb and temperatures where they become optically thick, using both ALMA bands 3 and 6. These observations will be compared in detail with optical, UV, and EUV observations from space. | The Sun | Sun | 2018-08-24T00:00:00.000 |
| 3454 | 2024.1.00476.S | 0 | Investigating the CI/CO Abundance Ratio of Shock-Excited Gas in the Small Magellanic Supernova Remnant | Atomic carbon line emission (CI) is thought to be a good tracer for deducing the H2 distribution in galaxies as well as low-J CO line emission. However, it is not fully understood how CI/CO abundance ratio is modified under the environment where cosmic-ray induced and/or shock destructions of CO molecules occur efficiently, and lower metallicity. We propose to observe CI(3P1-3P0) toward molecular cloud associated with SNR in the SMC which provides excellent laboratory to measure the variation of CI/CO abundance ratio through cosmic-ray induced and/or shock destructions of CO without any contamination along the line of sight. In particular, the high ratios due to the shock-destruction of CO can be seen only directions of the shock front and/or inside SNR, whereas cosmic-ray induced destructions will affected the whole molecular cloud owing to their energy-dependent diffusions. The impact of due to the low-metallicity on CI/CO can be confirmed by comparing ratio between the ratio in the SMC, the LMC, and our Galaxy. ALMA is the only telescope that can study the shock, cosmic ray, and lower metallicity induced astrochemistry with sufficient angular resolution and sensitivity. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3455 | 2015.1.00089.S | 25 | Anatomy of a midlife crisis: can sigma Orionis disks still make Jupiters? | The prevalence of extrasolar Neptunes, with masses that are large enough to undergo runaway growth in the presence of gas suggests that the timescale for planetary core formation and disk gas dissipation must be quite similar. We propose to examine this directly by measuring the gas and dust content of circumstellar disks in the middle-aged (~3-5 Myr old) sigma Orionis cluster. Our sample consists of all 92 spectroscopically identified members of the cluster with Spitzer mid-infrared excesses. Our previous JCMT/SMA observations show that disks have low, but detectable, dust masses and are associated with gas. We will achieve a dust mass sensitivity of two Earth masses, sufficient to detect the mean level of continuum emission. We will also be able to measure the gas content of the disks to Jupiter mass sensitivity through observations of the 13CO and C18O 2-1 lines. This sensitive, uniform study of a large, similarly-aged sample will be a benchmark for disk evolution studies and inform planetary synthesis models. If insufficient gas remains in these middle-aged disks to form Jupiters, we will be able to place firm limits on the formation history of our Solar System. | Disks around low-mass stars | Disks and planet formation | 2017-09-16T17:11:49.000 |
| 3456 | 2019.1.00350.T | 64 | Investigating A Diversity in The Final Evolutions of Massive Stars toward Supernovae | Recent optical observations of core-collapse supernovae (CC-SNe) have led to an emerging picture that the massive stars are much more dynamic in the last few years than widely accepted previously; existence of dense circumstellar matter (CSM) confined in the vicinity of the SN progenitor has been inferred. However, the nature of CSM derived from the optical data has a large uncertainty, and the optical emission is sensitive only to the extreme CSM case. A quick ToO at the mm wavelengths within ~10 days after the explosion is unique and powerful diagnostics of the CSM environment. Our ALMA observation in Cycle 6 was successfully conducted for one CC-SN, and the data show the natures of the CSM around the SN different from optically-derived cases; it is less dense and more extended, showing that ALMA provides a less biased tracer of the CSM than the optical data and can probe a different regime in the properties of the CSM. With the emerging diversity in the nature of the CSM, we propose ToO observations of one CC-SN at Bands 3 and 6 in Cycle 7. This relatively handy project will bring us new and robust information on the yet-unclarified final evolution of massive stars. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2022-11-22T10:37:30.000 |
| 3457 | 2015.1.00117.S | 58 | A Full Inventory of the Molecular ISM in Two Starburst Galaxies at z=5.7 | We propose a full molecular line inventory in Bands 3 and 4 of the two highest known redshift dusty starburst galaxies accessible by ALMA, at z=5.7, close to the end of cosmic reionization. A carefully-constructed tuning setup targets more than 40 lines of 13 molecular species expected to be detectable in these objects, tracing the full range of excitation conditions, heating mechanisms, outflow and dynamical signatures, and chemical enrichment pathways. At these rest frequencies, our observations will match and even exceed the sensitivity of local starbursts observed by Herschel/SPIRE. By exploiting high-resolution ALMA 870um continuum observations, low- and mid-J CO observations with ATCA and ALMA, [CII] emission from APEX, and full optical-to-radio SED coverage, these observations will stand as the definitive view of the ISM conditions in these objects, serving as an effective comparative study to local starbursts (e.g. Arp220) and intermediate-redshift analog systems (e.g. the Eyelash). In one target, we aim to spatially resolve the molecular line emission, allowing a 1 kpc-scale study of the near-Eddington-limited star formation underway in this object. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-07-05T20:12:21.000 |
| 3458 | 2018.1.01060.S | 39 | TEMPLATES: Targeting Extremely Magnified Panchromatic Lensed Arcs and Their Extended Star formation | We have been awarded 55 hours to observe four gravitational lensed sources with JWST through the ERS Program. This JWST program will spatially resolve the stellar components and the star formation in galaxies across the peak of cosmic star formation (1.3 | Starburst galaxies, Gravitational lenses | Active galaxies | 2019-12-22T11:33:28.000 |
| 3459 | 2018.A.00066.T | 26 | CO spectroscopy of GRB 190829A that exploded in a dust-enshrouded environment | This is an urgent DDT to observe GRB 190829A that is only the second GRB with detected photons beyond several hundred GeV. This event also has one of the densest lines of sight towards a GRB afterglow to date, which makes it ideal for observing molecular absorption. This observation will help us understand the connection between the very dense environment of this GRB and the very high energy emission. The observation will cover the CO(1-0) transition at a redshift of 0.08. We expect to detect this transition both in absorption and in emission. VLT/X-shooter spectroscopy has revealed that the line of sight is very dense. Detecting molecular absorptions with ALMA would be a first for GRBs. At the same time we expect to see CO emission from the host galaxy which is more massive than usual GRB hosts. These data will be combined with optical and near infrared afterglow spectroscopy obtained with X-shooter at the VLT, and with an extensive follow-up campaign in radio from another ALMA programme, from ATCA and from GMRT to produce an extensive study of the interstellar medium. | Starburst galaxies, Gamma Ray Bursts (GRB) | Active galaxies | 2020-07-02T16:53:13.000 |
| 3460 | 2017.1.00069.S | 109 | What is the Origin of the Spiral Structure in the Protoplanetary Disk around Elias 2-27? | Gravitational forces in protoplanetary disks can excite spiral density waves that result in spiral structure of different amplitude, pitch angle, location, and number, depending on the driving mechanism and the disk physical properties. Recent 1.3 mm ALMA observations have revealed a pair of trailing symmetric spiral arms in the disk around the pre-main sequence star Elias 2-27 (Perez et al. 2016, Science). The spiral arms extend to the disk outer regions and can be traced down to the disk midplane, while inwards of the arms, a gap in the disk emission is observed. To understand the origin of these spirals, we propose new ALMA observations in Band 3 and Band 7 at 0.2'' resolution that will trace both the dust and gas component in the disk. By constraining the spectral index of the dust continuum emission (Goal A) and determining the contrast of these spiral arms in the gas component of the disk (Goal B), we aim to discern what is the origin of these structures and provide a new benchmark for theoretical simulations of spiral density waves in protoplanetary disks. (Note: This is a resubmission of program 2016.1.00606.S, with no data acquired in C4 as of March 15, 2017) | Disks around low-mass stars | Disks and planet formation | 2019-02-15T20:26:09.000 |
| 3461 | 2013.1.00967.S | 15 | Dust Opacity and Fragmentation in the Centers of Nearby Low-mass Starless Cores | With the windfall of recent continuum observations of nearby star-forming regions using Herschel and large ground-based bolometer arrays, it is imperative that we reduce the factor of a few uncertainty that currently exists in (sub)millimeter dust opacities. This uncertainty strongly affects determination of the core mass distribution and core stability. In this proposal, we will directly address two key issues in studies of the nascent phase of star formation - starless cores: (1) what is the dust opacity index (beta) at (sub)millimeter wavelengths, and (2) do starless cores fragment on scales of 100 - 1500 AU? We shall observe a sample of 5 bright, nearby (125 pc) starless cores in the Ophiuchus cloud complex at 2.1, 1.2, and 0.86 mm at 100 AU resolution. We will determine the dust opacity index by radiative transfer modeling of the observed visibilities and compare the results to existing 160-1200 um observations. Our sample includes cores with a range of central densities (1.0e5 - 1.0e6 cm-3) and dynamical states (stable to collapsing) in which to search for fragmentation and to search for variations among the cores in the dust opacity index. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-06-03T11:07:13.000 |
| 3462 | 2013.1.00139.S | 13 | The Extinction-free Metallicity Indicator for High-z Galaxies: Its Calibration and Application at z=3 | Measuring the metallicity of galaxies at various redshifts is fundamental to investigate the physical process regulating the chemical evolution of galaxies. So far the metallicity of galaxies has been measured up to z~3.8; however, the conventional metallicity diagnostics exploit rest-frame optical emission lines, which prevent us from measuring the metallicity beyond z=4 due to the limited NIR atmospheric window. A more serious problem in the conventional methods is that they cannot be applied to heavily-obscured dusty young galaxies, that are the crucial population to study the galaxy evolution. To overcome these problems, we have developed a new metallicity indicator that consists of FIR fine-structure lines, the flux ratio of [NII]205/[CII]157. In Cycle 0, we have shown that this ratio is fairly high in a galaxy at z=4.8, suggesting that massive galaxies experienced their major chemical enrichment at very high-z. Here we propose to calibrate this indicator by observing this ratio for z~3 galaxies, whose metallicity has been measured also by conventional methods. Once we calibrate this FIR metallicity indicator, we will establish the new way for metallicity studies beyond z=4. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 2016-07-02T08:42:32.000 |
| 3463 | 2022.1.00223.S | 32 | Resolving the growth of massive galaxies in cosmic web filaments | The cosmic web filaments are thought to fuel the growth of galaxies and SMBHs under the current cosmological framework. Therefore growing galaxies exactly within a remarkable gas filament provides a unique laboratory. Recently invaluable targets have been discovered at a z=3.1 proto-cluster core. A number of bright submillimeter galaxies (SMGs) are found to reside in Mpc-scale Lyman-alpha filaments, which is suggestive of fueling by the cosmic web. Newly obtained ALMA 1.1mm images of the SMGs uncovers a number of internal structures, like clumps and cores, at 300-500 pc scales. While these would hold a key to understand what is going on in and around the galaxies, currently kinematical information at a comparable resolution is lacking, which is a big obstacle. Here we propose to observe [CII] and underlying dust continuum of the 6 SMGs at z=3.09 at 0.07 arcsec (or 500 pc) resolution. The resolution-matched data will enable us to understand (i) the mechanisms responsible for the starburst, (ii) resolved view of stellar mass assembly and connection to passive systems, and (iii) interplay with surrounding gas (in synergy with OH+ absorption). | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-06-19T02:29:00.000 |
| 3464 | 2019.1.00373.S | 7 | First Complete Mass Census of a z~2 HI Absorption-Selected Galaxy | From our dedicated ALMA program to uncover the CO emission from a sample of HI absorption-selected galaxies, we have found the surprising result that these systems have higher CO luminosities (and presumably higher molecular mass) than their emission-selected counterparts. This makes them ideal candidates for follow up observations to explore, in detail, the resolved kinematics of their molecular gas. In this proposal we are requesting 15.6 hours to observe the CO(3-2) emission at 0.21" resolution for one of these galaxies, B1228G. This target was selected because of pre-existing optical data, which provides an estimate of the stellar mass of this system, as well as an unobscured star formation rate from the detected Halpha emission. Furthermore, this system has a bright CO luminosity and absorption characteristics similar to the other galaxies in our sample. Besides being a pilot study for a larger program aimed at a representative sample of HI absorption-selected galaxies, the proposed observations will provide the first resolved molecular gas maps of a z~2 HI absorption-selected galaxy, allowing us to provide a complete census (molecular, stellar and dynamical) of its mass. | Damped Lyman Alpha (DLA) systems | Cosmology | 2023-01-10T14:51:51.000 |
| 3465 | 2019.1.00496.S | 6 | Digging deeper into the ringed pole-on outflow from DO Tauri | A promissing way to learn more about outflows may be available thanks to the great sensitivity of ALMA, that allows now to disect the gas layers in outflows oriented close to the line of sight. This ultimate point of view will allow to enter the inner part of outflows, close to the protostars, where the winds are launched and the jets are expected to drag and accelerate the molecular material. We propose to observe with great sensitivity and angular resolution the ringed outflow from DO Tauri, one of the few protostellar outflows oriented close to the line of sight known, as part of a follow up of our previous study of this source. | Outflows, jets and ionized winds | ISM and star formation | 2023-02-08T16:40:22.000 |
| 3466 | 2012.1.01111.S | 0 | Carbon [CII] at z=6.18 on a Quadruply-Imaged Lensed Galaxy Behind the CLASH cluster MACS0329 | A large number of galaxies have been discovered at z>6 using space- and ground-based facilities, the majority of which are very faint in the optical/IR and the detection of Lyman alpha emission to confirm their redshift has been a challenging task. A more complete study of these distant galaxies is needed, given their nature holds clues about the end of the epoch of reionization. ALMA offers new possibilities to study such galaxies via bright emission lines such as [CII]. Here we propose band 6 observations of [CII] in a quadruply-imaged lensed LAE at z=6.18, for which high-magnification and detailed lens models enable a comprehensive study of its properties. Our goals are : (i) to use [CII] as a critical probe of the interstellar medium in a z=6 galaxy; (ii) to estimate how effective the line is as a coolant for the ISM, compared to other galaxy populations at similar redshifts based on L_CII/L_FIR ratios, (iii) to place constraints on the total amount of gas in this galaxy by comparing the dynamical mass from the [CII] line width with the stellar mass obtained from the optical data; (iv) to assess whether this metal-poor z=6 galaxy, demonstrates an enhancement of the [CII] emission compared to lower redshift, metal-rich star-forming galaxies; (v) to open up a new window to reveal the nature of these yet unexplored galaxy population, enabling studies of statistical samples and detailed studies with high-resolution observations. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2015-05-02T18:52:47.000 |
| 3467 | 2018.1.00526.S | 18242 | 3000 dusty starbursts at z>4 | We propose to carry out ALMA 1.2mm snapshot continuum observations of all ultrared dusty star-forming galaxies (DSFGs) in HATLAS (sources with S250 | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2020-01-17T17:29:07.000 |
| 3468 | 2021.2.00001.S | 192 | The 'Missing Link': Gas Accretion Flows in the Galactic Bar toward the Central Molecular Zone | We propose to observe 25 clouds in the Galactic bar with gas temperatures of tens of K and broad lines (>~10km/s) - these clouds are the best candidates for the gas flow that feeds the Central Molecular Zone (CMZ) of our Milky Way. Whereas the CMZ is a well studied region at all wavelengths (including the supermassive black hole Sgr A* and the vigorous star forming region Sgr B2), the streams that feed the CMZ have largely been neglected. Modelling shows that the gas likely follows x1 and x2 orbits in the bar potential, enforced by the bar potential, with gas accretion at various points and cloud-cloud collisions from dynamical effects like (self-)intersecting orbits and accretion overshooting. We propose to probe these processes by observing molecular lines that trace physical parameters such as shocks, turbulence, temperature, ionization etc. The ACA+TP is the perfect telescope for our study as it allows us to probe relatively large regions at molecular clump resolution with adequate sensitivity. The data will provide an invaluable grid of cloud properties for improved detailed dynamical models of the inner Galaxy. | Galactic centres/nuclei | Active galaxies | 2024-05-25T19:33:17.000 |
| 3469 | 2012.1.00238.S | 0 | The Fomalhaut Asteroid Belt - Resolving the Traces of Terrestrial Planets | Fomalhaut plays an important role in studying debris disks and small bodies in other planetary systems. The proximity and luminosity of the star place key features of its debris system within uniquely clear view where detailed disk structures can be directly linked to its planetary configuration. In this proposal, we aim to resolve its asteroid belt at 345 GHz (870 μm), a warm disk component whose existence has been inferred from the observations by Spitzer, Herschel and ALMA, for the first time. The resolved image will allow us precisely determine the physical location and geometry (eccentricity and position offset relative to the star) of the warm belt, providing new insights into its nature and any unseen planets that might gravitationally shepherd the inner planetary system in Fomalhaut. | Debris disks | Disks and planet formation | 2015-08-13T13:30:05.000 |
| 3470 | 2021.1.01535.S | 176 | Timing the Disappearance of Molecular Gas in Post-Starburst Galaxies | Theoretical predictions of the "quenching" process predict that the absence of molecular gas (via e.g., depletion, removal, or heating) should precede the cessation of star formation. However, recent ALMA CO(2-1) observations have revealed that many (5/12) post-starburst galaxies retain significant gas reservoirs (log(M/M_sun)~10) in the 100 Myr after they shut down their primary epoch of star formation--and afterwards H2 is undetected. Though individually undetected, older (>100 Myr) post-starburst galaxies are constrained to have gas masses an order of magnitude lower than the young ones, even though the depletion times from star formation are ~25 Gyr. We propose an optimized survey which spans the full range of post-starburst properties and would detect all previously detected galaxies at SN>3. By doubling the initial ALMA investment, this survey will almost quadruple the size of the sample, thereby assembling the largest comprehensive sample of H2 measurements in quenched galaxies outside of the local Universe. This statistical census will conclusively describe disappearing H2 reservoirs and evolutionary timescales that will inform quenching models and cosmological simulations. | Starbursts, star formation, Surveys of galaxies | Active galaxies | 2023-02-08T07:22:58.000 |
| 3471 | 2016.1.01374.S | 95 | A search for the missing cold dark matter subhalos | We propose to observe three strongly lensed dusty, star forming galaxies (DSFGs) in band 7 to detect low-mass dark matter subhalos by measuring the minute distortions they cause in the lensed images of the background sources. The abundance of low-mass subhalos is a key discriminating prediction of the cold dark matter (CDM) paradigm, and strong lensing is a unique tool that can test this prediction. We have already made the first detection of a subhalo in ALMA observations of a strong lensing system (SDP.81) and have shown that this dataset is very sensitive to the presence of subhalos down to ~ 2X10^7 M_sun. This uniquely positions ALMA to measure the mass function of dark matter subhalos with unprecedented precision and thereby resolve one of the most important puzzles in modern cosmology. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-01-26T00:00:00.000 |
| 3472 | 2016.1.00633.S | 18 | Revealing the nature of the high-redshift star-forming galaxy SDP.81 with the CO 3-2 line | A strongly lensed sub-mm galaxy SDP.81 is currently the best-studied dusty starburst galaxy (DSFG), allowing a direct investigation of high-redshift star formation on scales <100 pc. A long-standing question is whether DSFGs are on-going major mergers, or large disks with orderly rotation sustained by cold gas accretion. Using our state-of-art lens modelling code working in the uv-plane, and following up on our previous work on this system (first lens model and continuum reconstruction of ALMA Long Baseline Campaign data), we are aiming at analysing the kinematic properties of SDP.81 on 0.1 - 10 kpc scales in order to distinguishing between the merger and large disks scenarios, and to provide the first resolved model of physical conditions in a high-redshift galaxy on <100-pc scales. We request ~6 hours of Band 3 time for observation of CO 3->2 line at 0.2" arcsecond resolution. The correlator setup used will also detect potential HCO+ and HCN emission in SDP.81. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-11-10T23:19:40.000 |
| 3473 | 2017.1.01178.S | 51 | Hot Water in HL Tau | Low mass protostar HL Tau is the topic of intensive study, in particular since ALMA Long Baseline Campaign observations revealed signs of planet formation in a protoplanetary system < 1 Myr. Here, we seek to followup on a recently-reported detection of hot water towards HL Tau. Water is believed to play a key role in star and planet formation, so understanding the nature of this emission is important. Previously interpreted as due to thermal emission, we believe the observations show indications of maser emission, and request ALMA high angular resolution observations at 321 GHz to confirm this, plus observations at 183, 325 and 658 GHz to enable constrained radiative transfer modeling. The observations will locate the masers in the system - are they associated with shocks in a jet or also in the disk - and can enable mapping of source structures on angular scales much smaller than the beam size. Radiative transfer modeling will provide physical conditions in the jet/disk. It can also measure the ortho:para ratio of water that may have been sputtered off cold dust grains. Detection of water masers towards HL Tau provides a new avenue for the study of low mass protoplanetary systems. | Low-mass star formation | ISM and star formation | 2021-02-12T18:28:31.000 |
| 3474 | 2024.1.01244.S | 0 | Resolving the extended structure associated with Apep's enigmatic wind | The enigmatic colliding wind system Apep has become established as a unique astrophysical laboratory comparable with singular systems such as Eta Carinae. As the only colliding wind binary (CWB) in a configuration with a pair of Wolf-Rayet stars, mid-IR imagery revealed that the system to be embedded within a spectacular sculpted spiral dust plume. Moreover, the kinematics were shown to violate prior established CWB physics with dust moving dramatically slower than the measured Wolf-Rayet wind velocity. This contradiction in the basic physics is profound and remains unresolved: how can the expansion of embedded dust (measured by proper motion) differ from the speed (established spectroscopically) of the most powerful winds known to stellar physics? One suggestion to reconcile the discrepant speeds posits that the central Wolf-Rayet star launches a wind with strong anisotropy induced by rapid stellar rotation. Such a model can be tested by observing the earlier generated and older dust shells. ALMA is the only telescope that has the sensitivity and resolution to track these relic dust shells, complimentary to recently scheduled JWST observations of the system. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2025-11-19T14:54:12.000 |
| 3475 | 2015.1.00308.S | 25 | The 12C/13C Isotopic Ratio in Protoplanetary Disks | We propose to obtain a direct meaurement of the 12C/13C and the 16O/18O isotopic ratios in two protoplanetary disk systems. Isotopic ratios are key quantities to extract physical (mass) and chemical (abundances) properties. Measurements of the the isotopic ratio in the bulk material also enable studies of the effects of isotopic fractionation such as that seen in galactic photodissociation regions which are direct analogs to the irradiated surfaces of disks. In disks the effects of isotopic self shielding are theorized to be the main mechanism for creating one of the more puzzling aspects of the solar system chemical record: the 18O enrichement (relative to 16O) in chondritic meteorites. Building upon techniques developed to characterize this ratio in the ISM we will obtain simultaneous measurements of 12C18O and 13C18O J = 3--2 transition in TW Hya and DM Tau. This simple meaurement can provide a direct estimate of the 12C/13C ratio. Simultaneous observations of 13CO J = 3-2 then can be used to determine the ratio of 16O/18O and test the process of isotopic self-shielding in the disk ennvironment for the first time with resolved observations. | Astrochemistry | ISM and star formation | 2017-04-13T16:54:55.000 |
| 3476 | 2013.1.01136.S | 5 | Measuring the Kinetic Temperature of Massive Star Forming Clouds in the LMC | The optically brightest, nearest, and with respect to angular scales most extended external galaxy, the LMC, undergoes vigorous star formation and contains a large number of molecular clouds. It is thus strange that there exists so far only a single published measurement of the kinetic temperature of its dense neutral gas. This proposal aims to fill this gap by mapping the 218 GHz para-H2CO line triple toward the massive star forming regions N113 and N159W, where APEX data reveal detections. The observations aim (1) at mapping the kinetic temperature for the first time in two prototypical massive star forming regions of low metallicity, (2) at providing badly needed temperatures as input for density estimates from other tracer lines, and (3) at identifying characteristic gradients in kinetic temperature, which are expected on both observational and theoretical grounds. Mapping the gas temperature in the two sources will for the first time allow us to obtain the kinetic temperature stratification of the dense neutral gas in a low metallicity environment irradiated by young massive stars. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2016-05-22T13:41:31.000 |
| 3477 | 2019.1.01721.S | 30 | Characterizing Absorption-Selected galaxies at High-z (CASH) Survey | We propose to continue our successful ALMA program to detect and map the galaxies associated with z~4 damped Lyman-alpha absorbers (DLAs) in CII 158 micron emission, by carrying out a search for CII emission from four DLAs at z~5.1-5.9, the highest redshifts at which DLAs have so far been discovered. The observations will obtain the first detections of the galaxies associated with DLAs at z>5, and will measure their SFRs, FIR luminosities, and ISM kinematics. They will measure the impact parameter of the associated galaxy to the DLA sightline, and test whether the extended HI reservoirs detected in our earlier ALMA observations are a generic feature of normal galaxies at the highest redshifts. They will also allow us to search for cold rotating disk galaxies at the highest redshifts, a probe of models of hierarchical structure formation: the galaxies associated with DLAs are good targets for such searches, as they are gas-rich galaxies that are not selected based on their stellar properties and are hence unlikely to be biased towards the clumpy, star-forming galaxies that are usually identified at these redshifts via optical imaging studies. | Damped Lyman Alpha (DLA) systems | Cosmology | 2021-04-20T17:59:51.000 |
| 3478 | 2021.1.01233.S | 46 | Molecular gas properties of merging galaxies with dual luminous quasars | We propose to use ALMA to map the molecular gas distribution using CO (J = 2-1) of five dual quasars having close projected separations between 3-13 kpc, an extremely rare population. With the Subaru Hyper Suprime-Cam (HSC) Strategic Survey Program, we have identified a population of SDSS quasars that have two components with nearly equal brightness separated by 0.6" to 3". Followup optical spectroscopy has confirmed these five dual systems and revealed two unobscured quasars and, in one case, an unobscured quasar paired with an obscured quasar. With ALMA, we will measure the gas mass hence gas fraction (highlighting that the stellar mass is log(M/M_sun)~10^11 in each case as determined from deep 5-band Subaru/HSC imaging) in spatially-distinct regions, kinematic properties such as the presence of rotationally-supported gas and the dynamical state of the merger for which such dual quasar activity is occuring. This would be one of the first studies on the cold ISM content in galaxies hosting dual quasars. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2022-12-20T06:56:22.000 |
| 3479 | 2013.1.00617.S | 9 | Extreme Star Formation "The Movie": the early assembly of monster stars and clusters caught in action | The ultimate goal of star formation (SF) studies is an end-to-end understanding of stellar mass assembly as a function of environment. Existing observations have two fundamental limitations reaching this goal: they predominantly focus on regions in similar environments, and observations of a region only provides a single evolutionary snapshot. This proposal aims to overcome both these problems by exploiting a causally-related system of clouds in the extreme environment of the Galactic Centre. ALMA observations will allow us to test whether SF has been triggered in these clouds by close passage to the bottom of the Galactic gravitational potential. If confirmed, this will provide a laboratory for studying stellar mass assembly as a function of absolute time, allowing us to: (i) directly test theoretical predictions of molecular cloud structure evolution in turbulent clouds; (ii) unambiguously determine how critical density thresholds for SF vary with environment; (iii) follow the mass assembly of gravitationally bound cores, including likely precursors to stars >100 Msun, thereby directly testing SF theories at the most extreme mass ranges. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-08-05T00:00:00.000 |
| 3480 | 2012.1.00008.S | 1 | High Resolution mm-Interferometry of a Highly Magnified Lyman Break Galaxy at z=3.07 | We propose high spatial resolution 3-mm ALMA observations of the CO(3-2) line emission in a z=3.07 bright gravitationally lensed Lyman Break Galaxy, LBG J213512.73-010143 (the `Cosmic Eye'). This LBG has previously been detected in CO(3-2) and CO(1-0) at lower resolution. Our previous CO(3-2) detection shows that the molecular gas is coincident with one of the two star forming components separated by ~2kpc in the lens reconstruction of the HST rest-frame UV morphology of the lensing system. High resolution observations in the extended configuration of this magnified system will spatially resolve the line emission at <0.7'' and allow us to map and dissect the molecular gas distribution on scales of ~0.2 kpc (in the source plane). Not only will the proposed observations allow us to determine the size of the CO emitting region and the dynamical mass, but they will also enable us to unambiguously determine the nature of this system and the interplay/distribution of CO emission and star formation activity in the progenitor of a `normal' galaxy in the throes of formation. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2017-04-14T15:20:31.000 |
| 3481 | 2018.1.01782.S | 5 | Mapping the Inner Edge of a Kepler-Analog Circumbinary Protoplanetary Disk | Kepler discovered several circumbinary planets around short-period (P < 40 days) binary stars, indicating that circumbinary planets form readily. A key input to any circumbinary planet formation theory is the radius at which the dynamical tides from the (possibly eccentric) binary orbit truncate the inner edge of the protplanetary disk. Through moderate resolution observations in Cycle 4, we have discovered that a circumbinary disk, whose orbital properties broadly match the sample of Kepler circumbinary planets, hosts a large dust hole ~25 au in radius. The inner edge of the hole is azimuthally asymmetric, and is quite a bit further out in the disk than one would predict from classical truncation arguments alone. It is an open question as to whether the gap is indeed the result of influence from the binary, is carved by one or more giant planets, or is a consequence of the advanced age of the system (16 Myr). We propose for high resolution (0.02"), sensitive dust continuum observations to map the asymmetry of the disk edge and determine whether the cavity is truly devoid of dust emission or contains the dynamical signatures of giant planets. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2022-05-27T00:00:00.000 |
| 3482 | 2021.1.01556.S | 3 | Resolving the gas, dust and stars in a spatially-extended z=2.24 starburst | Star-forming (SF) galaxies at the peak of cosmic star formation are observed to have high molecular gas fractions, extreme star formation effiencies, and turbulent conditions that differ substantially form local galaxies. We propose high resolution ALMA CO(J=3-2) observations of an H-alpha-identified SF galaxy at z=2.24, SHiZELS-14. kpc-scale, matched resolution data in H-alpha (from SINFONI/VLT), UV (from HST), FIR continuum (ALMA Band 6) and the radio continuum (VLA 4-8GHz) already exist. Unlike previous targets resolved by ALMA at this redshift, which tend to be ultra-luminous infrared galaxies with compact dust continuum emission, SHiZELS-14 displays spectacular extended dust emission, with well-resolved, clumpy UV and H-alpha emission. We propose to characterise the galaxy's molecular gas content and kinematics at comparable spatial resolution to our existing multi-wavelength data. With CO completing our unique dataset, we will study the efficiency of star formation and the buildup of stellar mass, and constrain alpha_C0, the critical calibration between CO line luminosity and molecular gas mass, all at high redshift and high spatial resolution. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2023-07-25T18:11:37.000 |
| 3483 | 2021.1.00769.S | 6 | Clump Scale Gas Kinematics in the Turbulent, Gas-Rich, Nearby Galaxy DYNAMO D13-5 | Normal, main-sequence galaxies at cosmic noon have morphologies dominated by massive star forming clumps. These galaxies are predicted to contain gas flows which transport material to fuel ongoing star formation. Likewise, clumps are potentially linked to the morphological transformation of these galaxies, if they are long-lived, bound structures. Yet, aside from a handful of extreme systems, it is difficult to acquire high-resolution observation to perform detailed kinematic studies of gas flows and clumps. We will address this with ALMA CO(3-2) mapping at 0.2'' ~280 pc in the nearby galaxy DYNAMO D13-5, whose properties are very similar to those of main-sequence galaxies at z ~ 1-3. We will: a) study the prevalence of inward radial gas flows in clumpy, turbulent star forming galaxies by searching for kinematic distortions and deviations from rotation, and b) study the kinematics of individual clumps to determine if there are gas flows associated with the clumps, and determine if they are bound systems through their virial parameter. These will allow us to provide valuable insight into currently outstanding questions that are crucial for deriving models of galaxy evolution. | Galaxy structure & evolution | Galaxy evolution | 2024-02-09T07:52:24.000 |
| 3484 | 2015.1.00393.S | 90 | CI observations toward compact molecular clouds associated with isolated intermediate- and high-mass YSOs in the LMC | High-mass stars usually form in giant molecular clouds as part of a young stellar cluster, but some isolated O/B stars are observed. What are the initial conditions that lead to the formation of these objects? The aim of the proposed observations is to measure the distribution and basic physical properties of the neutral gas associated with isolated intermediate- and high-mass YSOs in the LMC by observing [CI](1-0) line. We successfully mapped compact CO clouds toward 10 isolated YSOs with ALMA Cycle 2 based on the results of our previous Mopra observations. In spite of the fact that the compact clouds are even less massive than Taurus molecular cloud, the star formation activity therein is high. This fact may be because in the LMC the gas-to-dust ratio is higher and the UV radiation is stronger than in the Galaxy, and thus CO is photodissociated. In this case, [CI](1-0) is suggested to be another good probe for the molecular mass. The distribution of the neutral gas components without CO emission could be a significant mass component of the system, affecting the system's self-gravity and providing an additional supply of gas to fuel star formation. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2019-01-31T02:04:44.000 |
| 3485 | 2015.1.00483.S | 68 | The nature of the Centaurus A circumnuclear disk | We will use ALMA to obtain detailed images of the circumnuclear disk in the nearest giant radio galaxy, Centaurus A, in a selected number of molecular transitions. The set is designed to enable a comprehensive study of the physical condition and kinematical structure of its circumnuclear disk (CND). As the gas reservoir fuelling both a supermassive black hole (SMBH) and a massive outflow, the CND is the key to understanding the evolution of the radio galaxy core. Cen A is the only radio galaxy in which the CND can be studied in detail; all others are too distant. In the Cen A core, (i) the SMBH is surrounded by (ii) a cool CND from which matter falls in towards (iii) a 90 pc hot inner zone where much of it is deflected into (iv) a massive outflow of gas at modest speeds along the much faster jets emanating from the SMBH. With ALMA we will map the CND, hot contact zone, and the outflow region at a resolution of 20 pc (1") in order to determine the detailed spatial distribution of gas motion, density, mass, and temperature in the close vicinity of an actively accreting nuclear black hole, using the radiative transfer models developed specifically for such purposes. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2017-04-14T15:20:31.000 |
| 3486 | 2021.1.00318.S | 27 | Hot or Warm? What are the dust temperatures of normal star-forming galaxies at z~7? | We propose to observe the rest-frame 90um dust continuum (Band 8) to determine dust temperatures of six z~7 galaxies. We will probe the peak of the infrared emission, which directly offers a constraint on the luminosity-weighted dust temperature and provides an accurate estimate of total infrared luminosity. Our observations will resolve the unsettled debate regarding the trend in the evolution of dust temperature at z>4, whether it continues to rise or it flatten. This will give us an insight into how dust properties evolve at high redshift, and lead to a better understanding of what drives the efficient growth of the dust mass in the first billion years of the universe. Together with the existing [CII]158um and rest-frame 160um data (Band 6), we have designed the observations to obtain the dust temperature with an uncertainty as small as +/-3K. Our targets are a subset of the spectroscopically confirmed sample of the first ALMA systematic [CII] survey of normal star-forming galaxies at z>6.5. The combination of our observing strategy and the unique z~7 targets offers a rare opportunity to stringently determine dust temperatures and their evolution in the early universe. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2024-09-28T07:30:35.000 |
| 3487 | 2022.1.01232.S | 9 | Molecular gas conditions in the starburst-driven outflow in NGC 1482 | Starburst-driven outflows play an important role in galaxy evolution as they remove molecular gas from galactic central regions and suppress star formation. Although outflow dynamics has been studied in detail, some fundamental questions remain unanswered. What are the typical physical conditions of molecular gas? What is the CO-H2 conversion factor? How do clouds evolve in an outflow? We aim to address these questions by conducting molecular-cloud-scale observervations of NGC 1482, a nearby "M82-like" galaxy with a starburst-driven outflow. The target exhibits a spectacular outflow of hot gas traced by H-alpha and soft X-rays. Recently, ALMA detected molecular gas in CO (1-0) line in the outflow. The proposed sensitive observations of CO (3-2), HCN, HCO+ (4-3), CS (7-6) and 0.9-mm continuum, combined with auxiliary data, will probe the distribution and physical conditions of molecular gas in a biconical outflow and its interaction with hot gas, probe the nature of the outflow engine, and provide valuable input for outflow models. | Outflows, jets, feedback | Active galaxies | 2024-07-10T12:58:56.000 |
| 3488 | 2022.1.00558.S | 0 | Tracing Signatures of Infall onto Uranus | The Planetary Science Decadal Survey identified Uranus as "one of the most intriguing bodies in the solar system" (S-7) and named a Uranus Orbiter as the highest priority Flagship Mission for the coming decade. We propose new observations to explore the connection between this enigmatic world and its environment. Using ALMA Band 7 observations of CO, we will retrieve the vertical CO profile to measure both bulk planetary composition (i.e. oxygen abundance) and infall. Simultaneous measurements of HCN will aid in distinguishing between candidate infall processes that have been observed elsewhere in the outer solar system: comet impacts, interplanetary dust, or infall of water-bearing particles from rings or moons. The requested spatial resolution of 0.37" will permit the search for localized enhancements in these trace gases, expected to persist for decades after an impact event; and reveal the strong brightening of these spectral features towards the planetary limb, allowing us to improve the detection limit of HCN by a factor of 10. These observations will improve our understanding of ice giant formation and evolution, a key aspect of our solar system's history. | Solar system - Planetary atmospheres | Solar system | 2025-08-19T21:42:47.000 |
| 3489 | 2019.1.00008.S | 5 | Resolving star-forming regions in SMGs at a z=3 proto-cluster core | The advent of ALMA now allows us to dispose the morphologies of the interstellar medium (ISM) in submillimeter galaxies (SMGs). Some very recent works show that SMGs have complicated structures suggestive clumps, bars, and spiral arms, which provides new insights on SMG formation. But these current observations are limited to SMGs in general fields, and so environmental dependence is totally uncertain. To this end, we here propose 0.05" resolution imaging of 6 SMGs in band 6 at a z=3 proto-cluster core. The 6 SMGs are ubiquitously embedded in IGM filaments traced by Lyman-alpha emission, and 4 SMGs host a X-ray luminous AGN. Therefore they are ideal targets to investigate rapid growth of galaxies and supermassive black holes (SMBHs) in an extremely gas-rich, dense environment in the early universe. Our aim is (i) to uncover the distribution of the ISM in detail and infer the origin of starbursts, and (ii) to examine co-evolution of SMBH and galaxies in the starburst phase tracing dust and molecular outflow. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2022-10-01T17:21:14.000 |
| 3490 | 2015.1.01342.S | 18 | The Extreme Kinematics of Ionized Gas in the Central Half Parsec of the Galaxy | The luminosity of Sgr A* is considerably lower than that expected from accreting material falling onto a 4 million solar mass black hole. This is typically explained by radiatively inefficient accretion flow or jet models. It is possible that the accretion rate is much lower than that inferred. Recent VLA observations of the ionized medium in the inner few arcseconds have tentatively detected RRL emission with broad linewidths that extends beyond -800 km/s. It is unknown whether the emission is associated with the orbiting ionized gas or compact stellar sources within the inner few arcseconds of Sgr A*. We propose to utilize the unique capablities of ALMA Cycle 3 at Band 7 to determine the mass of this high velocity ionized gas with the radio recombination line, H26alpha. | Outflows, jets and ionized winds | ISM and star formation | 2017-08-10T00:35:23.000 |
| 3491 | 2022.1.01166.S | 0 | A high-resolution look at protoplanetary disk substructures in Chamaeleon | Rings, gaps, and spiral arms appear to be ubiquitous in protoplanetary disks, and they are crucial for a complete understanding of planet formation. However, their origin and actual impact on this process remain unknown, and the sample of sources observed at sufficient resolution to study these structures is still limited. Here we propose to obtain detailed (12-20 au) Band 7 observations of 47 protoplanetary disks in the Chamaeleon molecular clouds. These data will identify and characterize substructures using continuum and gas (12CO(3-2)) observations, ~doubling the sample size of disks observed at these scales. Together with previous studies in Taurus, the different ages and properties of Cha I and II will provide an evolutionary perspective of substructures that will help to build a more complete and homogeneous understanding of them. | Disks around low-mass stars | Disks and planet formation | 2024-11-21T00:03:25.000 |
| 3492 | 2023.1.00489.S | 0 | Measuring the Mean Molecular Weight of Gas in Debris Disks | Understanding the molecular makeup of gas in debris disks is one way of determining whether it is inherited from the protoplanetary disk phase (in which case it should be dominated by H2), or second-generation like the dust (in which case the H2 content should be very low), both of which have important implications for our understanding of the origin and evolution of planetary systems. So far, CO is the only molecule that has been detected in debris disks, despite a few sensitive searches for other tracers. Here we propose to determine the mean molecular weight of the gas in the debris disk around 49 Ceti, thereby determining its origin, using only measurements of CO molecular emission. Our method relies on two separate measurements that will break the degeneracy between the currently unknown H2 number density and kinetic temperature: we must (1) spatially resolve the vertical structure of the molecular gas disk, and (2) measure the excitation temperature via an optically thin line ratio. By combining these measurements, we can determine the mean molecular weight to a precision of 25%, thereby distinguishing a primarily H2 composition from a more cometary mix of gases. | Debris disks | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 3493 | 2021.1.00621.S | 100 | Are CO-rich debris disks primordial or secondary? | Debris disks are remnants of the planet formation process. Surprisingly, some debris disks contain considerable amounts of CO. These CO-rich disks have ages of tens of Myr, well beyond the typical lifetime of a protoplanetary disk. Two scenarios have been put forward to explain the origin of the gas: (1) The gas is primordial, i.e. leftover from the protoplanetary phase. (2) The gas is secondary, i.e. produced from the collisional destruction of comets. Both scenarios would have profound consequences. Scenario (1) would imply a prolonged lifetime of protoplanetary gas, with a direct impact on the timescale available for the formation of giant planets. On the other hand, scenario (2) would allow terrestrial planets to accrete secondary, metal-rich atmospheres. We propose a survey of CO-rich debris disks to discriminate between these two scenarios. We will determine the molecular hydrogen density from non-LTE CO excitation analysis. Primordial gas should be hydrogen-rich, while secondary gas should be hydrogen-depleted. Understanding the origin of CO-rich debris disks is an important step forward in our understanding of the late stages of planet formation. | Debris disks | Disks and planet formation | 2023-03-17T09:54:32.000 |
| 3494 | 2019.1.00111.S | 90 | The Birth of Giants: Assembly of the First Massive Galaxies | Over the last decade, a coherent picture of the Universe during the epoch of reionisation has started to emerge. High-redshift quasar spectra have undoubtedly been the most polyvalent tools in the exploration of the first Gyr of the Universe. To obtain a pan-chromatic legacy sample of the brightest quasars at z~6, we have recently been awarded an ESO Large Programme (XQR-30) to obtain optical/near-infrared spectra of the highest quality in a carefully selected sample. Here we request ~1.5 kpc (0.3") resolution ALMA [CII] imaging of this sample of quasars. These observations are critical for a number of reasons: (a) characterise the host galaxy that cannot be traced in the optical/near-infrared and spatially resolve star formation and gas surface densities; (b) provide accurate systemic redshifts that are crucial to fully exploit the optical spectroscopy; (c) pin-down the frequency of merging events in z>6 quasar hosts. Together with accurate black hole masses from XQR-30, the ALMA data will also put the targeted quasars in the framework of the black hole-host galaxy co-evolution paradigm and shed light on the formation of the first massive galaxies. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2022-04-13T11:46:39.000 |
| 3495 | 2016.2.00025.S | 1067 | DEATH STAR: DEtermining Accurate mass-loss rates of THermally pulsing AGB STARs | Mass loss by a stellar wind is a decisive process for late stellar evolution. Through this wind, Asymptotic Giant Branch (AGB) stars are major contributors of synthesized elements and dust to their surroundings. The wind process is studied using dynamical wind models with the goal of developing a predictive theory of AGB mass loss crucial for stellar and galactic evolution. The most reliable method to measure mass-loss rates, and to provide constraints for the wind models, is through CO line observations, but further progress in this fundamental field is still limited by the large observational uncertainties, where the assumed size of the CO envelope is a major factor. To solve this problem we propose to directly measure the CO envelope sizes for a representative sample of typical AGB stars by observing the CO(2-1) and (3-2) emission using the ACA in stand-alone mode. With this data we will develop the most accurate description of AGB mass loss, needed over a large range of wind properties, uniquely determine the gas-to-dust ratios of the sources, and through the large bandwidths covered in band 6 and 7, provide a goldmine for legacy science for the evolved star science community. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2018-07-29T00:43:57.000 |
| 3496 | 2013.1.00516.S | 21 | Molecular isotopes as tracers of the i-process in Sakurai's star | In many instances of stellar evolution, especially at very low metallicity, H-combustion events (which trigger the so-called i-process) are encountered. The exact way in which the evolution of stars with H-combustion deviates from stellar evolution predictions is not clear. This is however important for the evolution of the first generation of stars in the early universe. A case where these models can be compared directly with observations is Sakurai's object, a post-AGB star that experienced a very late thermal pulse and where evolution can be observed in real time. The mixing of proton rich material into the 12C-rich He-shell induced exotic n-capture nucleosynthesis. In the case of Sakurai's object the high efficiency of this process in combination with the immediate ejection of the burning products offer a unique possibility to study the i-process. It allows even radioactive isotopes like 14C to be observed, which, due to its short lifetime, cannot be a remainder from previous evolutionary stages. The proposed observations of C, N, and O isotopes will be compared to the analysis of 3D hydrodynamical simulations. They will provide strong constraints on the i-process. | Post-AGB stars | Stars and stellar evolution | 2016-08-28T12:46:45.000 |
| 3497 | 2019.2.00075.S | 10 | ALMA High Resolution Images of Dust Rich Supernova Remnant with a Pulsar Wind Nebula | We propose a continuum study with ALMA of G11.2-0.3, the Galactic supernova remnant with a pulsar wind nebula (PWN) and dust emission detected by Herschel. Surprisingly, Herschel revealed PWNe are dust-rich using the analysis tool, PPMAP to probe dust at spatial scales of the best Herschel resolution (5arcsec). However, limited knowledge of the dust composition and the contribution of synchrotron (with existing millimetre synchrotron images having resolution typically 20arcsec), hinder a precise analysis of the dust mass. Here we will use ALMA to produce high angular resolution images of the synchrotron in a dusty Galactic PWN at spatial scales complementary to Herschel. We request 870micron, 1 and 3 mm images to map the dust and synchrotron in G11.0 where there are hints that the dust is different to interstellar grains. Our immediate science goals are (1) to determine the breaking point in the synchrotron power law index at millimetre wavelengths. This will be crucial for (2) pinning down the dust mass and properties in a supernova remnant. | Supernovae (SN) ejecta | Stars and stellar evolution | 2022-10-29T16:37:41.000 |
| 3498 | 2017.1.01138.S | 6 | Solar prominences under the hood: viewing the thermal structure of prominences for the first time with ALMA | Prominences are one of the most dramatic illustrations of how the magnetic field shapes the atmosphere of a star: the magnetic field somehow supports a cool, dense plasma in a hot, tenuous environment. In our solar system, prominences constitute the best example of natural plasma confinement. Prominences sometimes erupt, throwing vast amounts of magnetized plasma in the heliosphere, often in association with flares and coronal mass ejections. Understanding the formation of prominences and their temporal evolution is of the utmost importance for our understanding of mass loading in the corona, and of the interplay between plasma and magnetic field in stellar coronae. The observation with ALMA at high spatial resolution of solar prominences in two frequency bands will offer for the first time a detailed view of prominence fine structures at mm wavelengths. The measured brightness temperatures in Band 3 and Band 6 will unravel the internal temperature structure of the emitting plasma. These measurements will provide key constraints urgently needed by theoretical models addressing the central question of the energy balance of the prominence plasma within the hot solar corona. | The Sun | Sun | 2019-09-14T16:20:00.000 |
| 3499 | 2017.A.00032.S | 39 | A confirmation of a gravitionally unstable gas disk in the brighest unlensed submillimeter galaxy at z=4.3 | We propose observations of [CI] lines for the best-studied submillimeter bright galaxy at z=4.3. In our ALMA cycle-5 project, we map out for the first time the spatial and kinematic structure of molecular gas inside the compact starburst region through CO (4-3) line observations at 550 pc resolution. Exploiting the high-quality maps of gas mass surface density, rotation velocity and velocity dispersion, we find an evidence that the starburst disk is gravitationally unstable, implying that the self-gravity overcomes the internal pressure. The goal of this proposal is to confirm whether the gas disk is gravitationally unsable. We will address this using [CI](1-0) and [CI](2-1) lines. As we already knew the spatial distribution of gas, we need to accurately measure a total gas mass. If the [CI]-based gas mass is comparable with, or larger than, the CO-based measurement, we will conclude that the self-gravity overcomes the repelling forces, leading to the extreme starburst in early Universe. By adding the proposed 1.7 hours observations to the existing 14 hours cycle-5 data, this project will provide crucial information for understanding the origin of the most massive galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-08-29T00:00:00.000 |
| 3500 | 2018.1.01259.S | 336 | Probing the Structure and Chemistry of Previously Unexplored Giant Molecular Clouds | Giant molecular clouds are cold, dense regions of the interstellar medium that are crucial to galactic evolution as they are the sites of star formation. Despite their importance, these objects have not been explored extensively, and there is not yet a catalogue to enable robust target selection for telescopes with high spatial resolution and sensitivity capabilities such as ALMA and JWST. We propose ACA-standalone observations of 11 giant molecular clouds that have not yet been characterized with respect to both structure and chemistry. Our targets all fall within the so-called molecular ring about 4 kpc from the galactic center and will thus provide crucial information on the structure of fairly-unexplored regions that host a substantial portion of the galaxy's chemistry. These observations will lay the foundation for a catalogue of protostellar sources for future high-resolution studies with ALMA and JWST. Using the spatial resolution and sensitivity of the ACA, we will also 1) characterize the physical structure of these star-forming regions by identifying individual objects or clusters therein and 2) probe the chemical nature of both individual objects and the clouds broadly. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-09-06T22:15:00.000 |
| 3501 | 2015.1.00025.S | 44 | Zooming in onto the First Hydrostatic Core Candidate and young Class 0 in Barnard 1 | We propose to characterize the physical and chemical structureof the First Hydrostatic Core Candidate B1b-N and the nearby young class 0 protostar B1b-Sat high spatial resolution with ALMA. These low luminosity sources, located in a dense protostellarcore of high column density, drive each a compact molecular outflow with a short dynamical time scale (less than 1000 yrs for B1b-N).Previous studies have confirmed that the observed properties of B1b-N are compatible with a First Hydrostatic Core but could not exclude other hypotheses. ALMA provides the sensitivity and angular resolution to allow zooming both in the continuum (0.05'' or ~12AU) and in carefully selected emission lines probing the dense envelope and the molecular outflows(0.5'' or ~ 120AU), we shall be able to provide a definite answer to the evolutionary stage of B1b-N. The field of view includes the slightly more evolved source B1b-S as acomparison. Our team includes specialists of interferometric observations, chemical modeling and MHD simulations. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-01-15T13:14:16.000 |
| 3502 | 2022.1.00193.S | 3 | High-frequecy polarization observations of IXPE blazars | Multiwavelength polarization, and in particular X-ray polarization, can be an important probe of the magnetic field geometry, acceleration physics, and high-energy emission processes of blazar jets. The Imaging X-ray Polarimetry Explorer (IXPE) recently opened a new window to the Universe through high-energy polarization. Here we propose time-constrained (within +-3 days) polarization observations of IXPE blazar targets in band 7. The proposed observations will supplement our planned multiwavelength campaign in radio, optical, X-rays, and gamma-rays. Comparison of the millimeter-wave, optical, and X-ray polarization and measurement of the mm-optical-UV-X-ray spectral energy distribution of blazars will provide the data needed to determine, for the first time, the mechanism and location of the X-ray emission, as well as test particle acceleration models in supermassive black hole jets. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-10-14T07:15:02.000 |
| 3503 | 2023.1.00759.S | 0 | The First ALMA-JWST-HST Exploration of the Metal-Poor Star-forming ISM | The nature of the molecular gas at low metallicities is not well understood due to the challenges in detecting the CO molecule in metal-poor environments. Models predict that low metallicity galaxies have large reservoirs of CO-dark molecular gas and high CO-to-H2 conversion factors to compensate for the missing CO, but there are few observational constraints for these values below the metallicity of the SMC (20% Z_solar). With the proposed ALMA CO(2-1) observations of Sextans A (7% Z_solar) and IC 1613 (15% Z_solar) and complementary JWST and HST data, we will investigate the properties of the metal-poor ISM at unprecedented detail. Our CO observations will double the sample size of resolved CO clouds in galaxies with Z<20% solar. We will combine the CO data with dust extinction maps from HST and HI data from the VLA to quantify the CO-dark gas and anchor the CO-to-H2 conversion factor at 20-40 pc resolution. The requested CO data also provide necessary constraints for interpreting the JWST observations of the low metallicity ISM. The combination of these datasets in a metal-poor system is unprecedented and will provide powerful tests of theoretical models of star formation. | Dwarf/metal-poor galaxies | Local Universe | 3000-01-01T00:00:00.000 |
| 3504 | 2017.1.01512.S | 334 | Gas mass fractions in z>3 main sequence galaxies from ALESS | The ECDFS is one of the best studied cosmological deep fields. Through a 10 year effort, we have uniquely characterized the 870 micron selected galaxy population in this field across the electro-magnetic spectrum. One of the unique properties of this galaxy sample is its large number of main sequence galaxies at z~2 to 5. As major contributors to the comoving star formation rate density, these sources provide a unique laboratory to study the evolution of the comoving gas mass density and to relate the gas content of galaxies to the evolution of the star formation rate density at redshifts z>2.5. So far no consensus of the comoving gas mass density measured in representative galaxies at these early epochs has been emerged. We here propose to continue our efforts from ALMA cycle 4 to add gas mass estimates from CO line and long-wavelength dust continuum emission in ~20 main sequence galaxies in 3 redshift bins between z=2 to 5. Our study aims to cross calibrate CO and dust based gas mass estimates in our 870 micron selected sources with existing surveys at z=2-3 and to add new estimates of the gas mass fraction based on both techniques in two more redshift bins at z=3-4 and z=4-5. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-03-27T19:21:51.000 |
| 3505 | 2018.1.00024.S | 35 | Submillimeter H2O masers in high-mass YSOs | It is still unclear how angular momentum is extracted to allow mass accretion onto circumstellar disks and newly born YSOs even in low-mass star-formation. This "angular momentum problem" is also crucial for high-mass cases to understand mass accretion mechanisms. In ALMA cycle 0, we detected velocity gradients perpendicular to the outflow in the 321 GHz H2O maser toward a high-mass YSO Orion Source I. Our results show that the 321 GHz H2O maser could be a new probe for outflow rotation in high-mass YSOs. To verify this hypothesis, we propose the first survey of the 321 GHz H2O maser in 14 high-mass YSOs associated with the 22 GHz H2O masers. We aim to reveal dynamical structures of high-mass YSOs traced by the 321 GHz H2O maser. If we detect rotation motions with the 321 GHz H2O maser, we will discuss enclosed mass and specific angular momentum of the outflow quantitatively. Multi-transition data of the 321 GHz and 22 GHz masers will constrain density, temperature, and H2O abundance in the outflow. These data will provide outflow mass, linear/angular momentum, kinetic energy, and their loss rates, which are essential in theoretical models of high-mass star-formation processes. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2021-01-01T07:16:48.000 |
| 3506 | 2019.1.01272.S | 27 | Unveiling the nature of three pre- or proto- brown dwarf candidates in Barnard 30 | We have identified three pre- or proto-brown dwarf candidates in the dark cloud Barnard~30 using APEX/LABOCA, ALMA Cycle~1, and IRAM 30m observations. In this proposal we apply for ALMA time in band 6 in order to (i) confirm them as bona-fide B30 members (that is, reject them as extragalatic contaminants), (ii) study their kinematics to characterize them either as pre- or proto-BDs and (iii) derive important kinematical properties (infalling material, rotation, molecular outflows). To reach these goals, we apply for observations of the C18O(2-1) molecule. Up to now, there is only one confirmed pre-BD core, namely Oph B-11. Therefore, any other confirmation would be of extreme importance in the field of BD formation. | Low-mass star formation | ISM and star formation | 2021-07-24T06:29:50.000 |
| 3507 | 2023.1.01149.S | 18 | INSECT: Investigating the NaScent Environment of Cirumbinary planeTs | Circumbinary planets have been detected with Kepler and TESS observations. However, it is still an open question how is the formation and evolution of this class of worlds. In circumbinary disks, the gas eccentricity is expected to grow, increasing dust fragmentation and challenging the formation of pebbles, which are the building blocks of planets. We propose to observe seven circumbinary disks that have been carefully selected to characterize the cavity properties (size and eccentricity) together with the gas distribution in these disks, by combining deep observations of continuum, 12CO, 13CO, C18O, and N2H+. These observations will constrain the processes that may (or not) circularize circumbinary disks, facilitating (or not) in-situ planet formation. In addition, these data will bring for the first time a homogeneous analysis of the disk gas reservoir in circumbinary disks, which determines the final planet mass and migration, as well as the dust dynamics. The proposed observations will finally close the gap between models and observations of circumbinary disks. | Disks around low-mass stars | Disks and planet formation | 2025-02-26T18:21:49.000 |
| 3508 | 2019.1.00708.S | 74 | Resolving the emission of phosphorus carriers in a protosolar analog | Phosphorus is a key bioelement on Earth, yet there are very few astrophysical constraints on phosphorus carriers during star formation. We recently detected bright PO and PN emission towards the low-mass protostar B1-a with the IRAM 30m telescope, offering a rare opportunity to characterize the phosphorus carriers in a protosolar analog. We aim to follow up these detections in Bands 3 and 4 of ALMA, covering multiple PO and PN transitions with a spatial resolution of 1". We will determine the origin of the PO and PN emission within the protostar, map their abundances and excitation temperatures, use molecular tracers to explore the phosphorus chemistry, and make comparisons with the early Solar system phosphorus abundances. This project will provide valuable new insight into how a crucial bioelement is inherited in an analog to the Solar nebula. | Astrochemistry | ISM and star formation | 2021-04-21T20:29:44.000 |
| 3509 | 2018.1.01471.S | 73 | Cold accretion in silhouette - exploring the properties of the very deep absorption in Hydra-A | We propose observations of an extraordinarily deep absorption line in the classic, double-lobed radio galaxy Hydra-A that we discovered in Cycle 4. We find a narrow (<5km/s), deep (tau=1.0) CO(1-2) absorption that is slightly redshifted (+20 km/s) from the BCG systemic velocity with several weaker, broader lines at larger velocity offset. This very deep absorption allows us to search for a number of isotoplogues of CO and other high density tracers such as HCN and HCO+ with a very large potential dynamic range given the bright core (70-130mJy over Bands 3 to 6). Obtaining a census of the standard molecular tracers will allow a new insight into the chemistry of cold gas in cluster cores in general and allow us to constrain their physical properties (density, temperature, size) and link the apparent C, N, O and S ratios to their enrichment from the intracluster medium and/or stellar mass loss from the BCG. The balance of the absorption in this system being "deep, but not too deep" allows lines with an optical depth 25-50 times lower to be detected while avoiding the complications of line saturation, making this object unique in the local Universe. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy groups and clusters | Active galaxies | 2021-01-02T18:54:40.000 |
| 3510 | 2017.A.00056.S | 2810 | The nature of Planck compact sources at 353 microns | High frequency studies are a priority for ALMA, but in practical terms requires nearby (~1 degree) compact phase calibrators. The Planck satellite covered the same bands as ALMA soon will, detecting >40000 bright (>671 mJy) compact sources at 857 GHz, close to 1 per sq. degree and bright enough to be used as phase calibrators. However, the resolution is 4.4 and the positional uncertainty is 37, so the precise locations and source morphologies (i.e. compact or extended) are unknown. We plan to use the ACA in ALMA Band 6, which has a 40 FoV, to determine through short 30 second snapshots their morphology and positions. In this pilot, we select approximately 1500 sources at LST 22:0001:30 and lower than declination > 40 that appear in the Planck catalog at both 857 GHz and 217 GHz and not flagged as extended. This survey will have archival value both by improving the ALMA calibrator database and providing a sort of ALMA Galaxy Zoo finding any interesting sources, such as lensed high-z galaxies and mergers, for further study. | Surveys of galaxies | Galaxy evolution | 2018-10-10T00:00:00.000 |
| 3511 | 2015.1.01034.S | 62 | Uncovering the gas reservoirs of absorption-selected galaxies | Decades of research using absorption-line techniques have characterized the physical properties, including the surface density, chemical enrichment and molecular content, of the Universe's neutral gas. While these results undoubtedly link these absorption systems to galaxies, efforts to directly observe this association have been stymied by insufficient sensitivity and/or spatial resolution. Following on our successful Cycle 2 program, we propose to continue to use ALMA Band-4 receivers to carry out a sensitive search for redshifted CO(2-1) emission from six strong HI absorption systems at z<1. These represent the best candidates for a search for CO emission based on absorption redshift, gas metallicity, and putative galaxy counterparts. The proposed observations will allow us to (1) obtain the first detections of molecular emission from absorption systems, (2) derive the star formation efficiency in the absorbers, by comparing the SFR with the estimated molecular gas mass, and (3) compare the gas dynamics revealed through metal-line absorption, H-alpha nebular emission and CO molecular emission. | Damped Lyman Alpha (DLA) systems | Cosmology | 2017-02-28T23:06:52.000 |
| 3512 | 2022.1.01477.S | 27 | Examining the Dust Dynamics Induced by Planet-disk Interaction | Migration of grown dust toward dust traps is crucial for facilitating the formation of pebbles and planetesimals. Specifically, the dust traps induced by planet-disk interaction have been well motivated and thus the theories are better understood. Thanks to the unprecedented sensitivity of ALMA, now we can base on diagnosing dust SED and polarized scattered light to yield tight constraints on the spatial distributions of maximum dust grain sizes and thereby constrain the theories. Surprisingly, these techniques have not been applicated to the PDS 70 disk, which is the only disk where the forming planets have been located by direct infrared imaging. It might be because it is not particularly bright and thus is disfavored in the early science phase of ALMA. Having sensed a strong desire to see such observations happen, we humbly pick up the task to plan this program. By requesting the 75 mas resolution, Band 7 full polarization and Band 3, 4 Stokes I observations, the immediate goals are (1) to verify the dust filtration induced by planet-disk interaction, and (2) to look for grown-dust vortices that are expected to be excited in the grown-dust ring. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2025-08-20T06:14:18.000 |
| 3513 | 2022.1.00360.S | 80 | ALMA-FACTS: FundAmental CO 1-0 Transition Survey of Nearby Galaxies | We propose a survey of 12 nearby spiral galaxies in the fundamental CO(1-0) transition and to study the systematic variations of the CO J=2-1/1-0 ratio (R21) on GMC scales within and among the galaxies. The 12 galaxies form the complete sample of the overlaps among the ALMA PHANGS, Spitzer SINGS, and Herschel KINGFISH surveys, and hence, the rich ancillary data from these surveys, including the CO(2-1) data, are available. The variations in R21, as a function of gas physical conditions, are theoretically predicted, and have been observed in the Milky Way and some nearby galaxies with limitations. Therefore, the proposed R21 survey will show the evolution of molecular ISM on GMC scales as a function of galactic structure and star formation (SF) activity (e.g., between spiral arms and interarm regions, in and outside bars, and from circumnuclear regions to the disk outskirts). Historically, CO(1-0) has been the yardstick of molecular gas observations, while CO(2-1) is now becoming a new standard due to its relative easiness of detection. It is essential to characterize any systematic effect in R21 with a survey of a large number of galaxies. | Surveys of galaxies | Galaxy evolution | 2024-09-20T16:32:15.000 |
| 3514 | 2013.1.00273.S | 17 | Gas and Dust in Newly Discovered Quasars at z~7: Probing Massive Galaxy Formation at the Highest Redshifts | High redshift quasars are likely hosted by the most massive and luminous galaxies in the early universe. We discovered four bright quasars at 6.6 | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2016-01-29T14:06:39.000 |
| 3515 | 2023.1.01707.S | 5 | Co-spatial gas feeding of SMBHs and remnant SF regions in "IR-pure AGNs'' | FIR radiation of galaxies is typically dominated by thermal emission of star-formation (SF) dust. However, utilizing Swift/BAT AGN Spectroscopic Survey we found 12 galaxies where the IR radiation is almost fully contributed by AGN even in FIR band (hereafter "IR-pure AGNs"). All of the IR-pure AGNs locate under local SF main sequence, suggesting the final phase of gas consumption and AGN life for this system. More interestingly, the depletion time of molecular gas by remnant SF is found to be tightly associated with lifetime of AGNs, impling that gas feeding of remnant SF and SMBH could be co-spatial, i.e., molecular gas distribution is compact with the SF region concentrated in the vicinity of SMBH. Therefore, the IR-pure AGNs are good candidates of galaxies with gas feeding both SF and SMBH, which could reflect a stage in co-evolution of SMBHs and host galaxies when SF is quenched in galaxy scale but remains in the vicinity of SMBH. In order to directly determine the compact gaseous structure and reveal the co-spatial gas feeding of SMBHs and circumnuclear SF remnants, it is crucial to trace the molecular gas in the IR-pure AGNs with spatially resolved observations using ALMA. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-12-07T01:11:29.000 |
| 3516 | 2024.A.00003.T | 0 | ALMA observations of AT2024wpp | AT2024wpp was discovered as a fast rising blue optical transient (FBOT) at a redshift of z=0.1 with luminous X-ray emission. FBOTs are a new class of transients with high luminosities, blue colors, and fast timescales that are inconsistent with traditional supernova models. Instead, models for FBOTs invoke central engines and shock interaction with dense circumstellar material. FBOTs have mainly been studied in the optical/UV regime, and the most optically luminous FBOTs (LFBOTs) show bright radio emission. LFBOTs are intrinsically rare, and only three LFBOTs have been observed at mm wavelengths to date. Early mm observations are critical to constrain the properties of the immediate environment of FBOTs. AT2024wpp offers a unique opportunity to monitor this rare and exotic transient in the mm regime. The transient is only ~6 days post-discovery and evolves at day-long timescales in the mm bands. We propose immediate observations of AT2024wpp with ALMA in Bands 3 and 5 and request 1.1 hours of DDT time. These observations will be complemented by GMRT, MeerKAT, and ATCA observations at lower frequencies and X-ray observations at higher frequencies to build the broad band SED. | Transients | Stars and stellar evolution | 2025-04-17T16:23:08.000 |
| 3517 | 2015.1.01571.S | 92 | Statistical nature of the class I CH3OH maser clumps in high mass star-formation | We propose high-resolution molecular line observations toward 44 GHz class I CH3OH maser sources to investigate the physical environment of shocked regions traced by 44 GHz class I CH3OH masers.Previous interferometric studies of Class I CH3OH masers suggests that the masers trace the shocked gas in the dynamical structures in star forming region, such as outflows, HII regions, and the cloud-cloud collision. However, the detailed kinematics and physical environment of the region where the masers arise are still unclear due to the scarcity of high-resolution data of shock tracers and masers. From 2013, we started observations of 15 MYSOs associated with 44GHz CH3OH masers with KaVA, and this sample will give a unique chance to study the detailed information of physical environment of the shocked regions where maser arises by comparing high-resolution observations of shock tracers to VLBI images of masers.We will observe CO and H30a to trace the outflows and HII regions, SiO to trace shocked molecular gas.to compare the physical properties of shocked region with each maser features observed with VLBI, the high-spatial resolution and the high-sensitivity of ALMA is inevitable. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2017-12-02T05:12:06.000 |
| 3518 | 2017.1.01088.S | 42 | Probing [CII] Emission Associated with Strong OI Absorption Systems in the Reionization Epoch | Intergalactic medium (IGM) metal absorption lines observed in z>=6 quasar spectra offer the opportunity to probe early galaxy feedback process, the nature of enriching sources and IGM topology in the reionization and post-reionzation era. We propose to carry out a pilot study of using ALMA Band 6 and Band 7 to observe a sample of three strong OI absorbers along three quasar lines of sight at z>=6. We will search for star-forming galaxies that could be the sources of IGM low-ionization metal enrichment. Our deep ALMA observations will detect [CII] emission and far-infrared (FIR) dust continuum of star-forming galaxies down to a [CII]-based star formation rate (SFR) of 12 M_sun/yr, and within impact parameters of 60 kpc from the quasar lines of sight. Results from this program will provide the first sample of galaxy-IGM connection at z~6, the end of reionization era. The results will be used to compare in details with cosmological simulations of the IGM and test models of IGM enrichment through galactic outflows. | Sub-mm Galaxies (SMG), Damped Lyman Alpha (DLA) systems | Galaxy evolution | 2019-07-04T19:39:46.000 |
| 3519 | 2011.0.00016.SV | 0 | Science verification observation of SDP.81 | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Gravitational lenses, Sub-mm Galaxies (SMG) | Cosmology | 2016-06-24T14:02:08.000 |
| 3520 | 2018.1.01177.S | 3 | Multi-Band Polarization of the Edge-On Disk L1527: A Critical Test for Grain Alignment by Poloidal Magnetic Fields | Measuring magnetic fields in circumstellar disks using dust polarization observations has, to date, proven to be unsuccessful. The main problem is two competing polarization mechanisms to magnetic field dust grain alignment: self-scattering and grain alignment from radiative anisotropy. On the other hand, edge-on young circumstellar disks offer two large advantages in measuring poloidal fields by maximizing the plane of sky component for a poloidal field, and providing gradients in optical depth along the minor axis that will cause magnetic field dust grain aligned polarization to flip from parallel to the magnetic field at high optical depth to perpendicular to the magnetic field at low optical depth. The young edge on Class 0 source L1527 is the perfect source to test for poloidal fields because we have 1) polarization observations at 1mm and 870 microns; 2) optical depth models in ALMA Bands 3 to 7; 3) predictive models of polarization emission based on that optical depth; and 4) evidence that radiative grain alignment is minimal in this source. L1527 Band 3 and Band 4 polarization observations are essential to reveal a poloidal field for the first time in a disk. | Low-mass star formation | ISM and star formation | 2022-11-03T17:54:10.000 |
| 3521 | 2017.1.01151.S | 58 | Resolving the structure of the multi-ringed GM Aurigae transition disk | Though multi-planet systems are now known to be common, their formation history is not well-constrained. Dust cavities in transition disks have long been proposed as signatures of forming planets, but discoveries of additional substructure in disks raise the possibility that we have begun to witness not just the formation of single planets, but also the ongoing assembly of multi-planet systems. However, because the mechanisms that shape transition disks are debated, high angular resolution observations are essential to characterize the morphology at a level of detail that can distinguish between competing scenarios for the origins of substructures. Recent mid-resolution ALMA observations reveal that the GM Aur transition disk has a triple ring morphology, presenting an ideal opportunity to study planet-disk interactions. To pin down the nature of the processes sculpting transition disks, we propose to (1) resolve the substructure of the GM Aur disk by imaging the dust continuum at 5 AU resolution, (2) spatially resolve the spectral index to infer how grain properties vary across the disk, and (3) image HCO+ to search for perturbations to gas kinematics in the central cavity. | Disks around low-mass stars | Disks and planet formation | 2018-12-20T11:13:33.000 |
| 3522 | 2016.1.00965.S | 121 | Chemical Diagnostics of Extragalactic ISM:The Case of A Starburst-Dominant Merger | [Eight of our requested science goals were observed and are under QA2. If they pass QA2, only 3 science goals in Band 3 need to be observed.] NGC 3256 is a starburst-dominant merger with ~10 times more luminosity than local non-merger starbursts such as NGC 253 and M82. Yet, the concentration of luminosity in NGC 3256 is much lower than that in compact obscured nuclei (CONs) like Arp 220, whose energy source is still in debate. Interstellar medium (ISM) properties in such diverse galaxies can be quite different, which can affect the star formation. Molecular tracers are tools to study these ISM properties. We propose to observe key molecular tracers in multiple transitions in Bands 3 and 6 in NGC 3256. Using tracers of shocks, UV-photons, X-rays, and star-forming cores, we will determine the driving forces of the chemistry in this galaxy. Comparisons with non-merger systems will let us examine how much feedback a merger system experience from on-going star formation and from AGNs or already formed stars. Differences will be highlighted by the comparisons with the on-going survey in CONs. Study of chemistry in NGC 3256 will highlight the diversity of ISM properties among galaxies. | Galaxy chemistry, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-02-03T18:04:17.000 |
| 3523 | 2012.1.00870.S | 8 | The contents of transitional disk cavities: is the gas as depleted as the dust? | Most young, low mass stars are surrounded by optically thick accretion disks. A small fraction of these stars show a remarkable depletion of dust in the inner disk regions. These so-called "transition" disks are thought to represent a brief, but extremely important, evolutionary phase between young, optically thick, protoplanetary disks and old, optically thin, debris disks. A number of mechanisms have been proposed to deplete the inner regions of transitional disks, including grain growth, photo-evaporation by the central star, and dynamical clearing by a recently formed planet. To determine the physical phenomena responsible for these cavities, measurements of the mass surface density profile, as traced by the gas and dust are essential. Up until now, sub-arcsecond imaging of the gas emission was unfeasible. ALMA's exquisite sensitivity can detect trace amounts of gas and dust inside the depleted regions, with an angular resolution high enough to resolve the inner disk. In this proposal, we request time with ALMA to image a subset of transition disks with large inner holes, large disk masses, and high accretion rates, that likely originate by either grain growth or dynamical clearing by a planetary companion. We propose to observe 12CO and its isotopologues 13CO, C18O, and C17O in the J=3-2 transition, to constrain the gas depletion inside the cavity. Since 12CO becomes optically thick at rather small column densities, we can employ the less abundant CO isotopologues. These will probe a range of 4 orders of magnitude in column density depletion inside the inner regions of transitional disks. Comparison between the amount of gas and dust depletion will allow us to discern between the proposed scenarios for the creation of transitional disk cavities. | Disks around low-mass stars | Disks and planet formation | 2015-12-02T18:50:21.000 |
| 3524 | 2021.1.00341.S | 66 | A Spectroscopic Redshift for the Most Luminous Galaxy Candidate at z~11 | Detailed studies of the ages and star formation histories of the most distant galaxies promise to reveal new insight into the epoch when the first sources emerged from cosmic darkness. Recent analyses of the spectral energy distributions of the only two spectroscopically-confirmed z>9 galaxies, MACS1149-JD1 and GNz-11, have been particularly informative. A Balmer break in the former at z=9.1 suggests active star formation since z~15, and the remarkable brightness of GNz-11 at z=11 indicates that luminous sources may somehow emerge very promptly. However, until now, GNz-11 has been regarded as an anomaly. Here we propose an [OIII]88um spectral scan for a second promising luminous candidate, XMM3-3085, whose SED indicates a redshift z~10.8. Both sources are consistent with being drawn from the bright end of UV luminosity function at z=5-10. It has been challenging to secure a redshift for XMM3-3085 with ground-based near-infrared instruments because of the faintness of rest-UV emission lines. Confirmation of a high redshift for XMM3-3085 can be economically secured with ALMA and would strengthen evidence for the rapid emergence of luminous galaxies only 400 Myrs after the Big Bang. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-02-16T19:52:36.000 |
| 3525 | 2019.1.01177.S | 13 | A search for 16O18O in a protoplanetary disk | In the current paradigm of protoplanetary disk evolution, disks undergo chemical evolution over time, with important chemistry happening both on the surfaces of dust grains within the disk (e.g. formation of complex organic molecules), and in the upper layers of the disk (e.g. photochemistry). Our chemical models of protoplanetary disk midplanes predict that, for >5 Myr disks, the grain-surface chemistry should produce significant amounts of O2 ice which then desorbs into the gas-phase inside the O2 ice line, as well as gas-phase production of O2 in the upper layers of the disk. Observationally, however, this prediction is very difficult to validate because 16O16O does not have a permanent dipole moment. In this proposal, we aim to observe the 16O18O isotopologue in the nearby TW Hya protoplanetary disk. A successful search will demonstrate conclusively that gas-phase O2 can be a significant reservoir for elemental oxygen in disks, and that chemical evolution in disk midplanes can change the chemical composition of disks over time. | Disks around low-mass stars | Disks and planet formation | 2022-05-04T15:28:25.000 |
| 3526 | 2012.1.00173.S | 1 | An ALMA 1.3-mm image of The Hubble Ultra Deep Field | We propose to use ALMA in Cycle 1 to obtain the first deep, unconfused, and unbiased mm-wavelength image of the sky of sufficient depth (S_1.3mm = 0.12 mJy, 4-sigma) to detect dust-enshrouded star-formation rates down to 25 solar masses per year in galaxies across virtually all of cosmic time. The obvious location for this first deep, blank-field, mm continuum survey is the central 4 square arcmin of the Hubble Ultra Deep Field (HUDF). At a declination of -28 deg this field is ideally placed for ALMA observations, and is already the location of by far the best optical/infrared imaging and spectroscopy in existence. Moreover, in summer 2012 our team is obtaining the deepest ever near-infrared image of the sky in the HUDF, via 128 orbits of HST Cycle 19 WFC3/IR imaging (the UDF12 project). Combining our proposed new ALMA mm imaging with our final UDF12 HST dataset, we will be able to undertake the first meaningful study of the relationship between dust-obscured and UV-visible star-formation activity from z ~ 1 out to z ~ 8. Specifically, since we already posses spectroscopic/photometric redshifts, star-formation rates, stellar masses, and morphological information for all of the > 2000 galaxies detected in the HST imaging to date, it will be straightforward to determine which galaxies house dust-enshrouded star-formation activity (as a function of redshift, stellar mass, morphology, and UV slope etc). Consequently, breakthrough science will flow immediately following completion of our ALMA mosaic. To demonstrate the diagnostic power of our proposed ALMA image to discriminate between alternative theories of the evolution of star-formation activity and dust, we present a set of simulations in which the 1.3-mm flux from the known HUDF optical-infrared galaxies is produced on the basis of alternative, physically-motivated prescriptions for dust-enshrouded star formation. These alternative scenarios predict ~50-100 sources at our chosen depth (i.e. more sources than the 45 pointings, confirming the efficiency of mosaicing at this depth), with not only differences in source counts but also dramatically different redshift distributions. This program is ideally suited for ALMA Cycle 1, as the sensitivity gain to Cycle 2 is less dramatic than from Cycle 0, and because we do not require (or indeed want) very high spatial resolution (we deliberately choose 0.7 arcsec to minimize surface-brightness bias and thus maximise sample completeness, while still ensuring an unconfused image and excellent astrometry). By careful design our proposed ALMA image requires < 20 hours of total observation time, does not require the best weather, and yet will reach ~20 times deeper (and be ~20 times sharper) than the existing mm-wavelength imaging in the HUDF. This project will thus revolutionize mm-wavelength astronomy, yield immediate high-impact science and publicity, and provide a first high-profile example of how ALMA and HST can be combined to provide a complete view of the cosmic history of star formation. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 2016-07-31T10:13:29.000 |
| 3527 | 2019.1.01718.S | 124 | PHANGS-CMZs: Uncovering the Lifecycle of Galactic Nuclei by Mapping Extragalactic 'Central Molecular Zones' | Star formation, feedback, and gas dynamics in galactic nuclei are tightly intertwined with galaxy formation and evolution, but the multi-scale physics governing these systems are poorly understood. We will drive major progress by mapping the molecular gas properties and dynamics from kpc- to cloud scales, across a carefully-selected sample of five nearby galaxy centres, diverse enough to span the episodic variation of the nuclear star formation activity predicted by theory and simulations. We propose to map CO(3-2) on cloud scales (0.2, 10-20 pc) to resolve the galaxy centres into individual molecular clouds of ~10,000 Msun. In combination with our ancillary data from ALMA, HST and MUSE, these observations allow us to quantitatively characterise (1) the physical origin of SFR variations, (2) the origin and fragmentation of nuclear rings, (3) the conditions needed for young massive cluster formation, (4) the physics of star formation and feedback under high-pressure conditions, and (5) the feeding of gas towards the central black hole. This will significantly advance our understanding of the detailed physical processes that drive the large-scale properties of galactic nuclei. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2021-01-10T18:25:55.000 |
| 3528 | 2024.1.01212.L | 0 | DiskStrat: The first comprehensive picture of chemical vertical structures in proto-planetary disks | Protoplanetary disks, where planets form, are 3D highly structured objects. ALMA has excelled in revealing the variety and complexity of radial dust and gas substructures in disks - including rings, cavities, spiral arms, and azimuthal asymmetries. Most of them can be explained by ongoing planet formation. However, the vertical gas & dust structures of disks remain poorly understood. The latter is composed of 3 main layers : 1) a hot disk atmosphere, 2) a warm molecular layer, & 3) a cold midplane, all shaped by the disks physical properties, i.e. gradients in temperature, density, radiation and visual extinction. Due to their viewing geometry, edge-on disks provide unique targets to unambiguously disentangle the radial and vertical structures of disks, allowing direct imaging of the vertical structures. We propose a Large Program to map out the vertical chemical structure of disks and unambiguously constrain the relationship between dust & gas distribution in a sample of 9 edge-on disks carefully selected, all with JWST data. This ALMA LP will provide a fundamental legacy for our understanding of protoplanetary disk diversity & the initial chemical compositions of forming planets. | Disks around low-mass stars | Disks and planet formation | 2025-10-25T07:15:21.000 |
| 3529 | 2019.1.00297.S | 416 | A comprehensive sample of the two [CI] lines in lensed high-redshift galaxies | The two optically-thin [CI] fine-structure lines are valuable tracers of the atomic gas in galaxies. Additionally, [CI] has been demonstrated as powerful alternative to low-J CO lines as tracers of the molecular gas, when they cannot be observed. Because of its simple energy levels, [CI] is a direct estimator of the gas kinetic temperature and can be used to break degeneracies in models of the interstellar medium. We propose to observe 39 [CI](1-0) or [CI](2-1) lines with ACA in high-redshift, strongly lensed dusty star-forming galaxies (DSFGs) from the South Pole Telescope sample. Combined with our ancillary extensive data, we will assemble a sample of 31 galaxies with both [CI] lines detected (62 lines in total), which will address the following questions: 1) What is the gas mass in DSFGs? Do the various gas-mass tracers (dust, CO, [CI]) agree with each other? Can we combine these constraints to obtain more accurate gas mass estimates? 2) What are the conditions within the ISM (gas temperature, radiation field, density) of DSFGs? Finally, this sample will have an important legacy value to interpret and calibrate the results from other fine-structure lines or dense-gas tracers. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2021-02-12T23:34:14.000 |
| 3530 | 2019.1.00013.S | 39 | Mapping the water megamasers in the Circinus Galaxy | Water megamasers provide the best means of probing the physical conditions and accurate geometries within less than 1 pc of active galactic nuclei (AGN). Sub-millimeter water masers allow us to investigate with unprecedented detail the accretion disk and map so far uncharted regions. This is only now possible thanks to the superior sensitivity and resolution that ALMA provides. We propose here a sensinsitive observation of the sub-millimeter water maser lines at 183, 321, 325 and 658 GHz towards the Circinus galaxy, which is the nearest AGN hosting powerful pc-scale maser disk. Both the 183 and 321 GHz lines were previously detected with ALMA, but have never so far been resolved. The detection and imaging of all these lines will give us an entirely new insight into the kinematics and physical state of the accreting material that is within the sphere of influence of the supermassive black hole at the center. An analysis of the strength and distribution will allow us to : i) map the gas temperature and density to very high angular resolution, ii) improve our geometric disk models, iii) test unification schemes and iv) constrain radiative transfer models. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-05-31T19:11:00.000 |
| 3531 | 2011.0.00133.S | 0 | Can old protoplanetary disks be as tiny as 10AU? v1.7 | ET Cha is one of only three well-known nearby, gas-rich, TTauri protoplanetary disks with an age beyond 8 Myr (the other two being TW Hya and PDS 66), hence crucial for our understanding of late stages of disk evolution. This object is of particular interest as it has a clear near-mid IR excess, with optical and near IR line detections, but previous attempts to detect this disk in the sub-mm failed. ET Cha may be representative of a new class of small disks that have remained undetected so far with current instruments. Our previous analysis (Woitke et al. 2011), using a large collection of multi-wavelength data, suggets that this disk could be as small as 10 AU, an order of magnitude smaller than other protoplanetary disks around young stars. Using ALMA's superiour sensitivity, we propose to observe this object in 880mic continuum as well as 12CO 3-2 and 13CO 3-2 emission lines, to enable a thorough analysis with novel high-quality disk models, to determine the total gas and dust mass of the protoplanetary disk of ET Cha, as well as it's outer radius and temperature. | Debris disks, Disks around high-mass stars | Disks and planet formation | 2013-09-25T13:39:56.000 |
| 3532 | 2023.1.00525.S | 0 | Direct measurement of planet-forming gas mass using line pressure broadening | The gas mass in the main planet-forming regions of protoplanetary disks is one of the most important parameters for understanding planet formation processes. However, measuring the gas mass has been challenging due to the lack of an H2 gas tracer. The recent discovery of the pressure broadened CO line wings has allowed the first direct and accurate measurement of the gas mass in a protoplanetary disk. Based on this groundbreaking discovery, we propose deep observations of the 12CO 3-2 line in four protoplanetary disks to detect the pressure-broadened line wings, as well as the 13C18O line to measure the CO column density. By combining these observations, we will determine the H2 gas mass in the main planet-forming regions and robustly assess their planet formation potential for the first time. The proposed observations will revolutionize the measurement of planet-forming gas mass. | Disks around low-mass stars | Disks and planet formation | 2025-09-16T15:24:51.000 |
| 3533 | 2023.1.00937.S | 45 | Characterizing the complete disk population of young massive stars. Insights into planet formation mechanisms. | This is a simple, small survey program to obtain millimeter continuum and CO line fluxes for the complete population of intermediate and high-mass YSOs (1.5-10 solar mass) within 750 pc, 77% of which have never been targeted with ALMA. Using the ACA, we will cover representatively the whole parameter space of massive star formation in age, stellar mass, and effective temperature, for a volume-complete population of intermediate and high-mass forming stars. Hence, this ACA-standalone survey will provide the means to characterize the disk evolution, star formation mechanisms, and the planet formation potential of a large sample of disks distributed representatively throughout the whole massive star formation regime. This will greatly improve the current biases affecting studies on this disk population. In addition, this survey will reveal which disks are bright enough in the continuum and line for follow-up by the community. To encourage its broad and immediate utility, the data proprietary period will be waived, and the flux measurements will be published within 6 months after data delivery. 77 sources (70% of the sample) are in the LST range encouraged for this Cycle in the ACA. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2024-12-14T22:06:14.000 |
| 3534 | 2019.2.00194.S | 119 | Quasar Feedback Survey: The impact of jets and outflows on the molecular ISM of quasar host galaxies | A fundamental outstanding question of galaxy evolution is what impact quasars have on the ISM and star formation in their host galaxies. Based on an extensive multiwavelength campaign, we have been conducting a systematic survey to characterise the multi-phase outflows and jets of z<0.2 quasars (L(AGN)>10^45 erg/s) in exquisite detail. Capitalising on this calibrated laboratory, our survey is in a unique position to determine the impact that these processes have on the molecular gas. We now propose to use the ACA to measure galaxy-wide CO(1-0) fluxes for the full, representative, sample of 17 sources, all with exquisite ancillary MUSE and multi-frequency radio observations at high spatial resolution. We will robustly measure CO luminosities (L'CO) and investigate the impact of the full range of AGN outflows/jets properties on the total gas masses, star formation efficiencies and gas fractions. Combining with our pilot higher-J CO observations on half the sample, these ACA observations will allow us to measure line ratios and establish the physical conditions of molecular gas in these extreme environments. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2021-04-13T12:55:25.000 |
| 3535 | 2016.1.00484.L | 496 | Small-Scale Substructures in Protoplanetary Disks | We propose a Large Program designed to characterize substructures (e.g., gaps, rings, spirals, clumps, etc.) in the spatial distributions of solid particles for a well-defined sample of 20 nearby classical (i.e., not transitional) protoplanetary disks, using very high spatial resolution (down to ~6 AU scales) ALMA Band 6 (240 GHz) continuum observations. This survey will be the first to resolve material well into the planet-forming zones of disks with a uniform sensitivity and resolution (in to a radius of ~3 AU). In doing so, it will provide a homogenized look at the small-scale features that directly trace the planet formation process, quantifying their prevalence, variety of form, spatial scales, spacings, symmetry, and amplitudes, for targets with a diverse range of global disk structures and stellar host properties. Having access to that information will be transformative to the field: it will fundamentally shape our understanding of how planet formation is aided by -- and perhaps reliant on -- disk substructures, and it will provide essential context for the proper interpretation of all disk observations at coarser resolutions. Only ALMA can realize these goals. | Disks around low-mass stars | Disks and planet formation | 2018-10-12T17:05:10.000 |
| 3536 | 2016.1.00992.S | 17 | A keplerian and resolved disk in the O8-type protostar IRAS16547-4247 | This proposal aims to reveal the first case of a truly resolved (< 1000 AU) and Keplerian disk associated with an O-type protostar. We propose to obtain sensitive ALMA long baseline (0.05") observations of IRAS 16547-4247 at 0.85 mm. This source is a young and relatively nearby (2.9 kpc) O8-type young star. The 0.85 mm continuum observations will resolve the dust emission detected by Zapata et al. (2015) towards IRAS 16547 to measure the dimensions of the putative disk, while line observations will help in searching for Keplerian motions in the innermost parts of the disk. | High-mass star formation | ISM and star formation | 2018-10-09T07:31:37.000 |
| 3537 | 2018.A.00064.T | 24 | Can ALMA detect the first mm counterpart of a Fast Radio Burst ? A multi-wavelength campaign of the bursting FRB121102 | Fast radio bursts (FRBs) are bright and very short flashes of radio waves and form a new and enigmatic class of astrophysical transients. Till recently, FRB121102 was the only FRB showing a repeating activity with series of bursts indicating some clustering properties. It was also the first FRB for which a precise localization was obtained. It allowed follow-up multi-wavelength observations showing it is emitted from a low metallicity dwarf host galaxy with a quiescent radio counterpart. Our Nancay and Arecibo radio telescopes monitoring has detected 5 consecutive bursts in the past week. We have thus triggered our multi-wavelength observing campaign to follow the activity of FRB121102 since 30/08/19 and until 09/09/19. We propose here to carry out ALMA observations to try obtain, for the first time, the millimeter photometry of a bursting FRB. A very first detection of a FRB at millimeter wavelengths would be a unique result. The multi-wavelength photometry and radio spectral index of a FRB could be obtained for the first time thanks to our multi-wavelength observation campaign, putting unprecedented constraints on the various theoretical models so far proposed to explain FRBs. | Transients | Stars and stellar evolution | 2020-03-08T22:55:54.000 |
| 3538 | 2022.1.00122.S | 28 | Metallicity and dust content in J0100+2802, the most massive quasar in the reionization epoch | Having by far the largest black hole mass at high redshift, J0100+2802 at z=6.3 is the best laboratory to study if quasars truly represent the site of the earliest structure formation and chemical evolution. However, the currently available data marginally indicates that J0100+2802 has a dust mass surprisingly as low as a few times 1e+7 Msun, similar to those in normal star-forming galaxies without AGN at a similar epoch. This poses a severe question whether the target is chemically enriched system. The signature of multiple mergers, as revealed by a high-angular resolution image, is consistent with the possibility of lower gas-phase metallicity of the host galaxy than expected. Here we propose to observe four emission lines and Band 9 dust continuum of the target to securely measure the gas-phase metallicity and dust mass. We will test if J0100+2802 truly represents a chemically enriched system or an object with a relatively low metal and dust content. If the former is confirmed, it will evidence that the host galaxy of J0100+2802 is chemically enriched at z ~ 6, and if the latter, this will pose a severe question to the current understanding of the galaxy-BH coevolution. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-01-04T14:19:11.000 |
| 3539 | 2016.1.01372.S | 0 | Gravity vs B-field in massive-star forming clouds: Who is in the driving seat? | The details of what physical processes (between turbulence, gravity, or magnetic field) regulates the mass transfer from the large scales of clouds and filaments onto the small scales of clumps and cores is still highly debated. The origin of such a debate resides in our (past) inability to track the magnetic (B) field properties over such a large range of scales and densities that are involved in the star formation process. Here, we propose to use ALMA to map, on a few thousand AU scale, the B-field morphology and gas velocity field towards the massive-star forming infrared dark cloud G34. Combined with our large-scale study of the region, these new observations will provide, for the first time, a complete picture of energy balance in a massive-star forming cloud. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-11-26T10:17:03.000 |
| 3540 | 2023.1.01086.V | 0 | Peering into M87's Black Hole in Multiple Colors | The 2017 Event Horizon Telescope (EHT) observations of M87 revealed a ring-like structure at 1.3mm, interpreted as emission surrounding a dark shadow due to the gravitational light bending and photon capture at the event horizon. However, the origin of this ring needs to be better understood, and it may also be the result of photons emitted by plasma located beyond the photon-capture radius. In 2018, subsequent GMVA+ALMA observations of M87 discovered a similar ring-like structure at 3 mm, with a size approximately 50% larger than that of the 1.3mm ring. In light of these findings, we propose new observations of M87 with GMVA+ALMA at 7/3mm, which will be conducted in close proximity to the planned Bands 6/7 EHT observations. By obtaining a multicolored view (Bands 1/3/6/7) of the black hole environment, we aim to better understand the origin of the ring and the physical properties of the plasmas within the innermost accretion flows and jets. In addition, our proposal aims to locate the 7mm VLBI core with respect to the black hole, for the first time. This will enable us to determine whether the core represents the outer parts of the accretion flows or is a tau=1 surface of the jet. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 3000-01-01T00:00:00.000 |
| 3541 | 2015.1.00848.S | 2 | H2S: A New Probe of Hidden Luminosity in Orion KL | We propose here that 20" X 20" interferometric maps be carried out for the 2(0,2) - 1(1,1), 4(2,2)-4(1,3), and 9(7,2)-9(6,3) transitions of H2S toward the Orion Kleinmann-Low nebula (Orion KL). These lines were among >90 H2S transitions detected toward Orion KL using Herschel/HIFI. Modeling the line excitation reveals that the 9(7,2)-9(6,3) transition is tracing extremely dense gas that is likely irradiated by a mid-IR continuum which is stronger than observed. The source of this intense radiation field is presumably hot dust heated by massive embedded protostars. ALMA maps of the J=9 transition will therefore trace those regions exposed to the strongest sources of hidden mid-IR radiation. Maps of the J=2 and 4 transitions, on the other hand, will trace the global distribution of H2S and provide context for the higher excitation line. If Orion KL is indeed heated internally by massive protostars, the sources identified by the proposed observations may represent the origin of Orion KL's tremendous luminosity. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-02-10T18:34:38.000 |
| 3542 | 2024.1.01151.S | 0 | Outflow impact on dense gas in a nearby filament | Numerical simulations show that outflows are likely to have their most impact on the star formation process through their interaction with their surrounding envelope (the mass reservoir of the forming star). Observational studies are needed to determine whether these models represent what really takes place in molecular clouds. Here we propose to conduct ALMA observations of the gas surrounding protostars in OMC 2/3, a dense filament in the Orion A cloud that is scheduled to be observed with JWST, in order to: 1) characterize the dynamical state and structure of the dense circumstellar gas in a typical region of star formation; 2) combine ALMA and JWST observations to fully characterize jets and outflows by probing both the hot shocked gas (JWST) and the entrained (cool) gas (ALMA); 3) investigate the impact from stellar feedback on the dense infalling envelope gas, within ~10^4 au of protostars; and 4) determine how these properties vary between sources at different evolutionary stages within the same star-forming region. | Outflows, jets and ionized winds, Intermediate-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3543 | 2016.1.01546.S | 64 | First direct molecular gas measurements in normal z~4.5 star-forming galaxies | We propose a pilot project to observe the CO(5-4) line plus the dust continuum close to the IR peak in four normal, main sequence, star-forming galaxies at z~4.5. From this we will measure for the first time directly the molecular gas content, the corresponding gas fraction, and the molecular gas depletion timescale in such high redshift galaxies. The observations will also allow us to compare the direct measure of the molecular gas mass from CO to that estimated from the dust mass, assuming a constant dust-to-gas ratio. Our sources are selected from a large spectroscopic survey in a field with abundant ancillary data. Combined with recent and ongoing observations targeting z~2.7-3.5 galaxies, our ALMA measurements will allow us to study the redshift evolution of the molecular gas fraction and depletion timescales beyond z~2 and out to z~4.5. This will provide important tests and constraints on our understanding of gas accretion and star formation in the high redshift Universe. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2018-05-18T04:06:40.000 |
| 3544 | 2016.1.00748.S | 50 | Probing Subsurface Water Ice Reservoirs on Ceres: Below the Diurnal Thermal Skin Depth | We propose to continue our NASA-funded Ceres thermal mapping campaign in ALMAs Cycle 4 to probe subsurface water ice reservoirs through seasonal thermal modeling. The water outgassing discovered by Herschel and new results from Dawn suggest that water ice exists below but close to the surface of Ceres. The distribution and state of water ice in Ceres likely contribute significantly to the evolution and geology of Ceres, and are key to understanding the formation and evolution of Ceres and of other water-rich objects in the solar system. Ceres is the only water-rich object in the main-belt with spacecraft observations available, making our ALMA thermal mapping program unique. Our first ALMA thermal mapping of Ceres in Cycle 3 revealed a strong contribution from subsurface thermal emission, likely originating from below the diurnal thermal skin depth. Therefore, a second epoch of observations is not only important for detecting the annual temperature changes on Ceres, but essential for investigating subsurface thermal emission for better modeling of diurnal temperature data at each epoch. We plan to observe Ceres in Band 6 over its full rotational period of 9 hrs in June 2017. | Solar system - Planetary surfaces, Solar system - Asteroids | Solar system | 2019-12-13T13:26:14.000 |
| 3545 | 2023.1.01296.S | 0 | Searching for cold molecular gas in a massive, recently quenched galaxy at z=3 | Understanding how supermassive black holes (SMBH) quench their host galaxies is a central problem in extragalactic astrophysics. The proposed physical mechanisms fall in two classes: 'ejective' and 'preventative' feedback. The first removes the gas from the disc, interrupting star formation; the second stops the inflow of cold gas, so star formation continues until the gas in the disc is used up. Investigating the gas content of old quiescent galaxies cannot disentangle these mechanisms, because too much time has passed between quenching and the time of observation. JWST enables us to measure the quenching time of newly quiescent galaxies with a precision of 10s of Myr. We propose to measure the molecular-to-stellar mass ratio of GS-10578, by observing CO(3-2) in Band 3 for 10.9h. We will also measure the SFR on timescales of 100s Myr by observing the cold-dust continuum in Band 7 for 1.3h. GS-10578 is a massive galaxy at z=3 which became quiescent only 30 Myr prior to observation. This system represents the most recently quenched massive galaxy known, so it represents our best opportunity to investigate SMBH feedback free from the confounding effects of evolution after quiescence. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-12-31T19:59:30.000 |
| 3546 | 2022.1.01357.S | 72 | Grain growth in the early protostellar systems revealed by eDisk | ALMA has shown protoplanetary disks with rich substructures and even with protoplanets. These features and the gas depletion timescale of protoplanetary disks (about 2 Myr) suggest that planet formation may start in earlier young stellar objects (YSOs). To study grain growth with such early systems (Class 0/I YSOs) as the starting signature of planet formation, we propose to observe the eDisk targets at Band 3 with the same angular resolution of 0.05 arc-second. Addition of the long wavelengths to the Band 6 data obtained by eDisk will allow us to study the radial and vertical distributions of grain sizes by mapping the dust opacity spectral indexes and by radiative transfer modeling. These grain size distributions will be compared with the dust continuum and molecular line features nicely captured by eDisk. In addition, we can reliably estimate dust mass at the long wavelength with minimal optical depth. This project will provide us an excellent opportunity to investigate dust grain growth and distribution toward planet formation in early protostellar systems. | Low-mass star formation | ISM and star formation | 2024-07-27T01:10:20.000 |
| 3547 | 2015.1.00228.S | 25 | An unprecedented view on the properties of the atomic and molecular ISM in a star-forming galaxy at z ~ 2.2 | The nature of the interstellar medium (ISM) in typical star-forming galaxies during the peak in star formation (SF) activity of the Universe (z = 1-3) is still unknown. We propose to observe 12CO and [CI] lines and the dust continuum to determine the dominant physical properties of the ISM and dust in a typical star-forming galaxy at z 2.2. The combination of these lines will allow us to unravel the density and temperature of the atomic and molecular ISM, the incident radiation field, the carbon mass and enrichment history, multiple proxies of the ISM mass, CO-to-H2 conversion factor, dust temperature and mass, and dynamical information. The proposed target is a typical example of the galaxies responsible for the bulk of SF during the SF peak of the Universe. The proposed observation marks the deepest attempt to observe low- and high-J CO lines and simultaneously [CI] lines in a main-sequence galaxy at these epochs and will allow us to study ISM physics so far only attempted for quasar host galaxies and sub-mm galaxies. | Galaxy structure & evolution | Galaxy evolution | 2017-03-03T11:40:38.000 |
| 3548 | 2017.1.01071.S | 120 | Active geology on Europa: hot spots, plumes, and surface anomalies | Our Cycle 3 observations of Europa revealed the presence of multiple regions on the satellite elevated in temperature by more than 10 degrees above that expected. Such hot spots could be regions where liquid water has intruded within hundreds of meters of the surface. Indeed, one such previously suspected hot spot, revealed in very limited Galileo spacecraft nightside thermal data, is coincident with the location of a recently suggested recurring plume on Europa. Hot spots could be regions of currently active geology and windows into the interior ocean. Unfortunately, our Cycle 3 observations cannot determine if these hot spots are caused by internal heating, by localized anomalies in thermal inertia, or by unusual surface properties. Measuring the temperatures of these regions as they move from morning to noon to afternoon easily resolves these degeneracies as different types of hot spots have very different temperature histories. We propose to obtain Europa thermal maps every 30 degrees of rotation to allow us to discover and map true hot spots on Europa for the first time. Such spots will be clear and exciting targets for future observation and exploration. | Solar system - Planetary surfaces | Solar system | 2021-01-11T22:14:20.000 |
| 3549 | 2019.1.01279.S | 10 | Measuring the luminosity of massive protostars via their millimeter brightness temperature | A major hurdle to improving our understanding of the process of massive star formation is the inability to determine the luminosity of individual massive protostars in deeply-embedded protoclusters. The problem is caused by the lack of high-resolution telescopes in the mid- to far-infrared that cover the peak of the Planck curve. Without being able to apportion the total luminosity among the cluster members, it is impossible to construct luminosity functions which might shed light on how clusters evolve. The advent of ALMA's long baseline capability offers a new technique for measuring the luminosity of compact millimeter sources via their brightness temperature. The high dust column density around a massive protostar makes it optically-thick to radiation shortward of about 1 mm wavelength. By measuring the angular size and brightness temperature at a few wavelengths near unity opacity, one can compute a luminosity estimate from the Stefan-Boltzmann law. By observing with 0.06" (130AU) resolution in Band 6 and 8, combined with previously observed Band 4 data, we propose to test this technique on the M17-UC1 region whose maser parallax distance has been accurately measured. | High-mass star formation | ISM and star formation | 2022-08-26T16:22:42.000 |
| 3550 | 2016.1.00671.S | 20 | Revisiting the star formation efficiency of low-metallicity starburst galaxy NGC5253 | With its supermassive star clusters, high star formation efficiency and low metallicity, NGC5253 is the best local laboratory to study globular cluster formation at high redshift. The offset of the Kennicutt-Schmidt law may be indicative of a non-standard mode of star formation, but this inference critically depends on the determination of the star-forming gas reservoir inside the complex, which is currently incomplete due to CO-dark gas and very opaque clouds (AV=50mag). We propose to observe the [CI] 1-0 and 13CO(2-1) lines in 8.9 hours at high spatial resolution (0.25" or 4pc) to recover the total molecular gas content. We will be able to reanalyse the star formation efficiency in NGC5253, and conclude whether the offset in the K-S law can be explained by the presence of a large CO-dark gas reservoir or requires a non-standard mode of star formation. Based on high-resolution line diagnostics from archival databases, we will construct a multi-phase ISM model and constrain filling factors for the various ISM phases. The quantification of the CO-dark gas fraction and the calibration of various line diagnostics will be crucial for high redshift studies of star-forming galaxies. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2019-04-26T21:51:42.000 |
| 3551 | 2012.1.00245.S | 11 | Spatially Resolved Mode of Star Formation in Halpha emitters at z>2 | We propose to conduct dust continuum observations on our original sample of narrow-band selected Halpha emitters at z=2.2 and z=2.5 in the Subaru/XMM-Newton Deep Field coordinated with the CANDELS-UDS field. Our samples are unique because the high-resolution optical and near-infrared images with WFC3/ACS on HST and the 1.1 mm image with AzTEC on ASTE are all available. In cycle-1, we will focus on the 11 Halpha emitters with MIPS detections. With the high-resolution (0.16") Band-7 observations with ALMA, combined with the comparably high-resolution (0.18") HST images at rest-frame UV and optical, we aim to resolve the internal distribution of star formation activities, both dust obscured and unobscured ones, for the first time. Moreover, we will characterize the mode of star formation within galaxies and investigate how the star formation activity is related to the internal structures such as clumps and mergers. | Starburst galaxies | Active galaxies | 2016-08-13T11:35:54.000 |
| 3552 | 2022.1.01743.S | 10 | Searching for substructures in young protoplanetary disks | Young protoplanetary disks around protostars play a fundamental role in the process of planet formation, since they contain the ingredients that will form planets. For a long time, the only tests to planet formation theories were in our own Solar system. This has changed completely over the last years with the discovery of a variety of protoplantary disks and planetary systems. However, it is not yet clear at which stage of the star and planet formation process dust grains start to efficiently coagulate and evolve from small solid particles to macroscopic dimensions. In this context, our proposal will focus into unveil the hidden subssctructures and geometry of two Class I's disk located in the Perseus molecular cloud using high resolution and multiwavelength observations. We will measure for the first time the level of of grain growth at scales of few tens of au in these young disks. Additionally, with no extra cost of observing time, we aim to detect a variaty of CO isotopologues ir order to characterize the rotationally supported disks by comparing their gas and dust structures. | Low-mass star formation | ISM and star formation | 2025-08-20T16:43:59.000 |
| 3553 | 2019.2.00249.S | 0 | Unexpected acceleration of the zonal wind in the Martian middle atmosphere | Recent observation has revealed an unexpected high abundance of water vapor in the Martian middle atmosphere that supposedly drives the enhancement of the atmospheric (hydrogen) escape. However, it is unclear how to extract water vapor from the lower atmosphere (water vapor is trapped below the cold-trap altitude) and place it in the middle atmosphere. Although our recent study has proposed that an inflation of the lower atmosphere associated with intensified meridional circulation can transport water vapor effectively to upper altitudes, the complete picture is not yet confirmed due to the lack of the direct observations of the atmospheric circulation (i.e., wind). We propose a new measurement to capture the vertical profiles of the mesospheric wind for the first time, using comprehensive multi-lines-observations by ALMA. In addition, our IR heterodyne observation can complement the wind measurements in the upper mesosphere. Also, satellite observations by MAVEN and TGO will observe the resultant thermal structure and water vapor, aerosol distribution in the mesosphere. | Solar system - Planetary atmospheres | Solar system | 2022-10-15T01:26:55.000 |
| 3554 | 2011.0.00006.SV | 0 | Science verification observation of BR1202-0725 | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | High-z Active Galactic Nuclei (AGN), Sub-mm Galaxies (SMG) | Active galaxies | 2016-06-24T14:02:07.000 |
| 3555 | 2023.1.00804.S | 0 | Feedback Chemistry in Gas Infall and Outflows of the Most Active Massive Starburst Galaxies at Redshifts 2-5 | Feedback regulated star formation throughout the history of the universe. The ground-state transitions of light hydrides are ideal tracers of stellar feedback in massive starburst galaxies back to the first billion years of cosmic time. We here propose to use the key oxygen hydrides to probe the molecular ion chemistry associated with outflowing and infalling gas vs. material found at the active sites of star formation in a statistically meaningful manner by detecting H2O+ in 40 z=2-5 starbursts with strong OH+ signatures. We will measure variations in abundances and column/volume densities and fractional ionization, as is critical to calculate mass/momentum outflow/infall rates of the gas supply for the starbursts in different phases and the local physical conditions in the absorbing layers, linking them to the star formation properties. These measurements will be key to understand the nature of the turbulent gas entailed in the large-scale outflows and infall associated with massive galaxies in the early universe in their peak starburst phase, and how they impact the resulting stellar population seen in their present-day counterparts at the end of the mass buildup process. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-12-05T11:00:14.000 |
| 3556 | 2023.1.00950.S | 0 | Water deuteration in extragalactic hot cores at low metallicity | Water is a key molecule tracing the chemical and physical processes associated with the formation of stars and planets. A crucial parameter for tracing the history of water formation is the deuterium fractionation of water: the HDO to H2O abundance ratio (HDO/H2O). HDO has recently been detected for the first time toward an extragalactic star-forming region, providing us an excellent opportunity to measure HDO/H2O in a significantly different environment than in today's Galaxy. The HDO 2_11-2_12 line was detected toward hot cores N105-2 A and B in the low-metallicity Large Magellanic Cloud (LMC). Our initial investigation using the astrochemical gas-grain model indicates that the H2O abundance may be reduced in the LMC by up to 30%. The existing HDO data reveal minor differences in water chemistry between the LMC and the Galaxy; however, the analysis is based on a single, low-S/N HDO line. Higher-sensitivity observations of both HDO and H2(18)O are necessary to determine HDO/H2O and address the question about if/how the physical and chemical properties of the environment affect water chemistry. We propose Band 6 and Band 5 observations toward N105-2 A and B to achieve this goal. | High-mass star formation, Magellanic Clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3557 | 2022.1.00453.S | 0 | Searching for volatile phosphorus at the epoch of planet formation | The potential habitability of planets depends on the availability of the fundamental elements for bio-chemistry at their time of formation. Phosphorus is of particular interest as it is essential for the synthesis of DNA. To date, current detections of P-bearing volatiles toward forming stars are associated with shocks. This supports the understanding that the bulk of the elemental reservoir of P is locked up in refractory materials. But, with the detection of volatile P in comet 67P it is unclear if there is actually a significant volatile reservoir of P locked up in ices. The search for volatile phosphorus in planet-forming disks is an important step in understanding the delivery of this bio-essential element to planets. Therefore, we propose to observe primary P-carries PO and PN in the planet-forming disk Oph-IRS48. In this disk, there is clear evidence for the sublimation of ices traced by complex organic molecules. If volatile P molecules are present in this disk, they should also be sublimated into the gas phase. Our proposed observations will be the first to fill a key gap between star-forming regions and comets. | Astrochemistry | ISM and star formation | 2024-09-12T16:45:45.000 |
| 3558 | 2013.1.00229.S | 18 | Circumnuclear molecular disks in early-type galaxies as a probe of black hole masses | ALMA will make it possible to measure masses of supermassive black holes in early-type galaxies via an entirely new method, by mapping the kinematics of rotating, circumnuclear molecular disks. HST images provide an optimal method for pre-selection of targets, because ~10% of early-type galaxies have circumnuclear dust disks on arcsecond scales which are associated with regular rotational kinematics. However, there are very few southern-hemisphere early-type galaxies that have round, symmetric dust disks and known CO fluxes. We propose 12CO(2-1) observations of the six best and most promising southern-hemisphere targets culled from an extensive search of the HST archives. Our efficient observations will resolve the gravitational sphere of influence of the black holes and reveal rapid rotation from molecular gas in the inner disks, and we will carry out dynamical modeling to derive constraints on the black hole masses. Once we have determined the CO fluxes and linewidths, in future ALMA cycles we will propose to carry out deeper and higher-resolution observations that will provide exquisitely accurate black hole masses. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2015-12-30T12:05:35.000 |
| 3559 | 2023.1.01518.S | 0 | Does the Accretion Shock Really Raise the Dust Temperature to Sublimate Volatile Molecules? | Recent observations reveal that rotationally supported disk has already been formed in very early stage of star formation. Such young disk is still growing in size and shaping up its vertical thickness to become protoplanetary disk in near future. An infant disk found in L1527 is a best target to study formation and evolution of such young disk, since it has the largest size among disks ever known around Class 0 protostars and the gas kinematics is well studied. In this proposal, we aim to obtain dust temperature distribution at the radius of centrifugal barrier, where accretion shock is expected. The expected temperature range just corresponds to the range (~50K | Low-mass star formation, Astrochemistry | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3560 | 2013.1.00356.S | 2 | Gas Physics in "El Gordo," a massive merging cluster at z=0.87 | We propose ALMA Band 3 observations of the Sunyaev-Zeldovich decrement towards ACT-CL J0102-4915 "El Gordo," a recently discovered z=0.87 massive merging cluster analogous to the famous "Bullet" cluster. This new system was discovered by the Atacama Cosmology Telescope in a large-area blind survey for clusters using the Sunyaev-Zeldovich effect. The cluster is a truly exceptional object, likely the most massive, highest temperature and most X-ray luminous among all known clusters at redshifts beyond 0.6. The goal of the proposed ALMA observation is to map the SZ signal at high resolution over the central 4 arcmin region of the cluster to measure the projected gas pressure using the SZ effect. The proposed ALMA observations will produce a direct measurement of the Mach-number from pressure jump at the merger shocks seen in "El Gordo" that can be used to confront the predictions for massive merging clusters at high redshift on the current LCDM paradigm. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2016-03-16T13:30:41.000 |
| 3561 | 2022.1.00646.S | 50 | Tracing the evolution of substructures: A high-resolution survey of old Upper Sco disks | The detection of substructures has been a revolution for disk and planet formation studies, as their presence is intimately linked to the assembling process of planets. Two ALMA Large Programs for dedicated substructure studies, DSHARP on protoplanetary disks and eDISK on younger embedded disks, have been and will continue driving the revolution of the disk field. The properties of substructures, including their shapes and locations, may change substantially when disk gas disperses (~5Myr and later). Constraining their evolution is key to identify major pathways of disk evolution and reveal the early evolution of planetary systems. However, such an analysis is halted by the lack of a comparing sample of more evolved disks. We propose for high-resolution (~0.03") imaging for 11 bright protoplanetary disks in the 5-10 Myr-old Upper Sco association, totaling a sample of 14 old disks when including the three with available data. With comparable resolution and sample size to previous high-resolution disk imaging programs, our requested observations will enable the first systematic exploration of how disk substructures evolve with time. | Disks around low-mass stars | Disks and planet formation | 2024-08-16T23:53:43.000 |
| 3562 | 2019.1.00915.S | 388 | Structural Evolution of Molecular Clouds Triggered by Supergiant Shells in LMC | We propose 12CO J=1-0 mapping observations of twenty molecular clouds along the "molecular ridge" in the Large Magellanic Cloud (LMC). Our aim is to illustrate the evolution of molecular clouds in the viewpoint of development of internal compact structures (which are directly relevant to star/cluster formation) and investigate the mechanisms that underlie the evolution -- in the LMC, the most likely trigger is interactions with supergiant shells (SGSs). The northern part of the ridge is a site of ongoing interaction between the gas and expanding (east to west) SGS, while its southern part is not associated with any known SGS. Therefore the ridge is an ideal target to test the SGS-induced evolution of the clouds. We expect that the proposed high-resolution (0.5 pc) high-fidelity images, obtained by combining the 12-m, 7-m, and TP Arrays, reveal the north-to-south (and potentially east-to-west) transition of internal structures of the clouds. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2021-03-18T05:27:50.000 |
| 3563 | 2024.1.01279.S | 0 | The Nested doll protostellar jet structure: Capturing the inner warm CO (6-5) molecular backbone of JWST jets | Jets and winds are of fundamental importance in astrophysics. Young stars are no exception: jets play a fundamental role in enabling stellar mass accretion and energy injection into their natal cloud. Jet models propose a "nested doll"-like expanding structure that should be predominantly neutral. In sharp contrast, JWST spectral images capture the fast-moving ionized components of jets, but we lack (as of now) any constraints on the inner warm molecularcomponent. Is there a molecular backbone? Is the primary jet molecular in the youngest protostars? We propose mid-J CO line (J=6-5) observations with ALMA Band 9 to trace the warm, fast-moving molecular counterpart of the collimated protostellar jets observed with JWST. We select a statistical sample of 16 Class 0 protostars in a single massive star-forming region, representative of Galactic star formation conditions. We will quantify the layered morphology and kinematics of the jets, winds, and outflows and study their dynamics from the combined JWST & ALMA observations, constraining the launching and propagation mechanisms in the youngest protostars during the first ~0.2 Myr of the stellar lifetime. | Outflows, jets and ionized winds, Intermediate-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3564 | 2016.1.01370.S | 18 | The new radial velocity planet in CI Tau: an ALMA search for sibling planets at radii > 4 A.U. | We propose high resolution continuum imaging of the disc of the T Tauri star CI Tau which has recently been shown to host an eccentric hot Jupiter at an orbital radius of $\sim 0.1$ A.U.. A primary motivation is to discover whether this planet has sibling planets at larger radial distances (as is often the case for hot Jupiters around main sequence stars) which may have played a role in deflecting the hot Jupiter into its present orbit. We show that we will easily be able to recover evidence of gaps in the disc produced by massive planets at orbital radii $> 4$ A.U.. Our secondary science goal, in the absence of detected structure, is to improve the estimate of the surface density of the inner disc. Our team combines experience in the analysis of mm observations with members of the discovery team of the hot Jupiter in CI Tau together with a number of theorists experienced in modeling various aspects of disc dynamics and planet-disc interaction. This places us in a strong position to interpret our results in terms of the likely dynamical history of the CI Tau disc/planet system. | Disks around low-mass stars | Disks and planet formation | 2019-01-27T00:00:00.000 |
| 3565 | 2013.1.01167.S | 7 | Exceptionally Bright Cluster-Lensed SMGs at z=2.0 and 4.7 | In the course of our large Herschel program, "The Herschel Lensing Survey (HLS)" (PI: Egami), we have discovered two exceptionally bright cluster-lensed submillimeter galaxy (SMG) at z=2.04 and 4.69. Their exceptional brightnesses (50-60 mJy at 870 um) and large magnification factors (x30 and x130) make them excellent targets for ALMA to conduct detailed observations. Our goal is to resolve these galaxies into individual star-forming regions with a spatial resolution of ~100 pc, comparable to the size of local giant molecular clouds (GMC). Scientifically, the first question to ask is the following: "Are GMCs in high-redshift IR-luminous galaxies super-sized versions of local GMC dense cores as shown by Swinbank et al. (2010) for the Eyelash galaxy?" By measuring the sizes and brightnesses of detected continuum sources and correcting the measurements for lensing magnification, we should be able to address this question directly. We will also probe the internal structures of various gas components, and will examine how the different phases of the ISM relate to each other (and to continuum), which will lead to a better understanding of the properties and origin of these galaxies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2016-09-23T17:38:34.000 |
| 3566 | 2024.1.00440.S | 0 | Where is the Dust? | ALMA has revealed dust to be common in UV-luminous galaxies in the epoch of reionization, indicating that dust must build up rapidly in the early Universe. Simultaneously, however, JWST observations suggest the z > 9 Universe to be dust-poor, at odds with theoretical models predicting that supernovae rapidly enrich their host galaxy with dust. So, where is the dust? We propose for deep Band 7 observations targeting the dust continuum of 4 carefully selected galaxies at 8.5 < z < 10.2. Our targets are the most luminous spectroscopically confirmed galaxies at z > 8 that are observable with ALMA. A similar selection technique at lower redshifts (5 < z < 8.3) has proven highly succesful, which suggests that - if dust is there - we will detect it. Our observations will thus place important first constraints on pristine supernova dust yields while we await multi-band ALMA follow-up. We moreover expect to detect the [OIII]88 line at high fidelity, enabling insight into the ionized ISM of our targets, in particular in combination with available JWST spectra. Our deep observations will place them onto the [OIII]-SFR relation and enable a search for outflows. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 2025-10-14T15:07:09.000 |
| 3567 | 2016.1.01147.S | 34 | The Heart of Darkness: Resolving Massive Protostellar Discs | The formation process of massive stars is not well understood, and it is unclear whether it is a scaled-up version of low mass star formation. Furthering our understanding requires high angular resolution observations of the circum(proto)stellar environments of young massive stars. Here we propose to observe two candidate Keplerian discs around young massive stars -- NGC 6334-I(N) SMA 1b and G11.92-0.61 MM 1 -- surrounding masses of 10-30 and >30 solar masses, respectively. Our proposed settings allow imaging on scales of ~200 au for both objects, in both the continuum and several molecular species (such as CH3CN, CH3OH and CH3CH2CN), which we verify with simulated observations of radiation transfer models. These observations will allow us to robustly assess several key aspects of discs around young massive stars for the first time -- the morphology (are they stable or fragmenting?), physical conditions (what are the masses and temperatures?) and kinematics (are they truly Keplerian?). In combination, these results will allow us to answer the fundamental question - do massive stars form in the same way as their lower mass counterparts? | High-mass star formation, Astrochemistry | ISM and star formation | 2018-09-05T16:07:12.000 |
| 3568 | 2016.1.00337.S | 49 | Probing into the Deep: Characterizing Substructure in Disks Around the Youngest Protostars | A hallmark of gravitationally unstable disks is their spiral structure and fragmentation due to self-gravity. Despite the progress and robustness of gravitational instability theory and simulations, observations of gravitationally unstable disks, traced by dust continuum emission in the disk midplanes, have thus far remained elusive. We have identified three protostellar systems with VLA-detected companions at ~20AU separations that are surrounded by >0.1 M_sun circumbinary structures. Given that the companion sources likely formed within these disks, we propose 3mm continuum observations at 0.078" (18 AU) resolution (same as the VLA resolution) to characterize the structure of the circumbinary disks and resolve the companion sources with ALMA. The proposed ALMA observations will be able to map the VLA-detected dust emission with a factor of ~6.6x higher S/N due to brighter dust emission at 3mm, enabling us to characterize substructure in the circumbinary disks, which could not be done with the VLA data. Thus, the proposed observations have the potential to reveal new details in the process of binary star formation and structure of gravitationally unstable disks. | Low-mass star formation | ISM and star formation | 2018-10-26T04:31:12.000 |
| 3569 | 2015.1.01510.S | 45 | Very Low Luminosity Objects in Molecular Clouds | Very Low Luminosity Objects (VeLLOs) are young stellar sources that are defined by luminosities less than 0.1 solar luminosity and rising mid-infrared spectral energy distributions. But what exactly are they: brown dwarfs or low-mass stars in formation, systems exhibiting low accretion, extremely young objects? We propose to characterize the VeLLO class through observations of 1.3mm continuum and CO J=2-1 outflow emission of a sample of 21 likely candidates in the nearby Ophiuchus and Lupus molecular clouds. Combined with our successful Cycle-2 program, this survey is expected to triple the number of confirmed VeLLOs as well as extend the class to sources with even lower luminosities. Our observations will provide estimates of their inner envelope masses, and help address questions concerning the nature of VeLLOs. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-06-23T21:00:28.000 |
| 3570 | 2013.1.00195.S | 7 | Dust Properties and Physical Conditions in the coldest dense core LDN183 | The Planck and Herschel data have identified regions of the interstellar medium (ISM) where dust is particularly cold (T<7K). These cold-cores (CCs) are likely to be very dense self-gravitating structures where star formation has not yet begun. Analysis of the dust spectral energy distribution (SED) of CCs revealed unusual dust properties, with very steep spectral emissivity indices (beta>3.5) -- in contrast to the much flatter spectrum of the Milky-Way (beta~1.8) -- that cannot be explained by classical dust models. Grain growth and aggregation that are likely to occur in cold, dense environments affects estimates of dust emissivity. This severely limit our ability to derive accurate masses and precise column density profiles from the dust emission, despite the wealth of high quality Herschel data available. The goal of this proposal is to use the excellent angular resolution of ALMA to determine the physical properties of LDN183, one of the coldest dust condensations known to date. We will take advantage of the wide bandwidth of ALMA to measure the dust continuum emission SED shape and to determine the density structure and thus the stage of prestellar evolution. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-07-20T11:28:00.000 |
| 3571 | 2018.1.01374.S | 11 | Deep into the nucleus of a protobinary system: mass accretion and orbital evolution caught in the act | Multiplicity in protostellar systems result from disk fragmentation and evolve to form binary systems. The dynamical interactions within a circumbinary disk are dictated by the accretion process of the disk material into the stellar components. However, the lack of molecular line observations at a few au hampers a detailed study on the kinematics predicted by models. Our team has high spatial resolution (~6 au) observations of the disk in the Class I YSO BHB07-11. The continuum data reveal an impressive structure of a binary system connected to narrow filaments. We propose a follow-up project focused on molecular line observations at similar resolution. We have selected lines that comprise all the excitation conditions expected to be found in the system: warm/hot (30 < Eu < 360 K) and dense (n > 1e6 cm^-3) gas. We will use high velocity channels to search for hints of infalling streams coupled to the dust filaments. We also include shock tracers to study the protostar-filament interaction zone and high excitation methanol lines to probe the presence of warm gas. Finally, we will map the continuum emission to obtain the dust distribution at higher frequency than our previous data. | Disks around low-mass stars | Disks and planet formation | 2021-01-18T15:56:28.000 |
| 3572 | 2011.0.00150.S | 0 | Testing planet and star formation in binary systems | The majority of stars are formed in binary systems. This means that a binary system is the typical environment both for star formation and for planet formation. The presence of a binary companion means that disks should be truncated, possibly influencing the prospects for planet formation. It is less well known whether or not the presence of a binary companion also influences the structure of the circumstellar disk or whether truncation only removes the outer disk, leaving the remaining disk with properties (e.g. surface density, grain size) similar to disks around single stars. While the structure and kinematics of disks around many single stars have been studied in detail, the effects of multiplicity on disk size and evolution are not nearly as well known. Here we propose to use the unprecedented sensitivity of ALMA to observe 17 known binary young star systems in Taurus for which the pair can be resolved, allowing us to characterize the disk properties and compare to those around single stars. These observations will test models of binary star formation, study whether disks evolve differently around the two stars in a binary system, and also examine the prospects for planet formation around individual stars in binary systems. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2014-01-04T21:06:00.000 |
| 3573 | 2019.1.01802.S | 50 | Molecular Outflows in Dusty Gravitionally Lensed QSOs at z=2-5 | Outflows are crucially important for the gas budget and evolution of luminous star forming galaxies and AGNs. QSOs, the most luminous AGNs, are believed to responsible for quenching star formation in the most massive galaxies. This suggests dusty QSOs are currently in a transition phase. The small fraction of star forming galaxies identified as as a QSO indicates this is a short (~1Myr) and extremely explosive phase. At the peak of star formation and AGN accretion at z=2-4, such outflows must play a major role, but become extremely difficult to observe in CO. In Cycle 3, we carried out a very successful pilot project to test OH+ as a tracer of high-z outflows. OH+ is a sensitive outflow tracer in local IR-luminous galaxies, and lies close to CO(9-8) so that both lines can be observed in one ALMA tuning. The OH+ line is detected in absorption, blueshifted with respect to the CO(9-8) which measures the warm gas in the disk. In this pilot study we aim to test the feasibility of detecting molecular outflows with OH+ in dusty QSOs at z=2-4, to compare with outflows in DSFGs at the same redshift and investigate the mass outflow rate and AGN luminosity relationship seen at low redshift. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2021-02-26T20:09:00.000 |
| 3574 | 2015.1.01447.S | 103 | The ALMA 1.2mm spectroscopic survey of the Hubble Ultra Deep Field: Exploring the deepest frontier | Our recent ALMA band-6 spectroscopic survey of a 1 arcmin^2 region in the Hubble Ultra Deep Field (UDF) has yielded about ten CO line candidates, sixteen continuum detections and, most interestingly, a handful of [CII]line emitting candidates at z>6. In this proposal, we seek to obtain a more than two times deeper spectral survey in band-6 in a single pointing field in order to capitalise over these exciting new results. Our main goals are to (1) constrain the CO luminosity function well into the regime of normal galaxies at z~1.5; Most importantly, (2) confirm the four [CII]line emitting candidates at z>6 in our target field. These deeper observations are the only means to confirm such z>6 sources, given the faintness of the Ly-alpha emission in the optical spectra, and will enable the exploration of the most sensitive flux levels in order to inform future deep molecular spectroscopy of the full UDF. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 2017-03-24T21:09:05.000 |
| 3575 | 2017.1.00506.S | 26 | Deep contiguous mapping of the densest proto-cluster cores at z=2.5 with ALMA | Our Mahalo-Subaru survey has identified an extremely dense proto-cluster at z=2.5 which shows 20 times higher number density of H-alpha emitters compared to the general field. It thus offers an excellent laboratory for us to investigate any early environmental effects during the peak epoch of galaxy formation. We propose to conduct very deep ALMA Band-6 observations on two 1-arcmin circled regions; ie. cluster center and an offset densest clump. We will sample dust continuum emission from narrow-band selected H-alpha emitters down to SFR=14Msun/yr and infer their gas masses in order to characterize their evolutionary stages (gas consumption/inflow/outflow processes) and their environmental dependence. Also we aim to discover new class of objects which can be visible only with ALMA, such as extremely dusty or gas dominated galaxies associated to the extreme environments. Combined with our existing rich multi-wavelength data-set including HST images and AO-assited H-alpha images, we will investigate how the mode of star formation (efficiency and gas fraction) changes with galaxy properties (stellar mass, sSFR, colour, and morphology), and how it depends on the environment. | Galaxy Clusters | Cosmology | 2020-03-14T00:00:00.000 |
| 3576 | 2017.1.01593.S | 44 | An Anatomy of Massive, Cold, and Highly Deuterated Cores Next to Warm/Hot Cores | This is a continuation of a B-ranked ALMA program in Cycle 4 to observe massive, cold, and highly deuterated cores next to warm/hot star-forming cores discovered in the CARMA, SMA, and JVLA observations. These cold cores are mm-quiet in the pre-ALMA observations, and seem to be starless or likely prestellar. A high detection rate (5/9) indicates that such entities may open a new window for the investigation of initial conditions of high-mass star formation. We observed two of the five regions during ALMA in Cycle 4, the data delivered recently showed that our scientific goals of revealing the fragmentation, turbulence, and dynamical properties of the cores could be fully achieved with the proposed ALMA observations. Here we propose to observe the remaining three regions in our sample. A preliminary analysis of the existing data showed that the completion of this project could significantly advance our knowledge of initial conditions of high-mass star formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-05-22T01:38:06.000 |
| 3577 | 2013.1.00523.S | 2 | Confirming the recent collisional destruction of an extra-solar Pluto | New STIS images of the extremely bright HD 181327 debris ring, a massive analog of our Kuiper Belt, reveal asymmetries consistent with the recent collisional destruction of a Pluto mass object. The STIS image also suggests size segregation in the disk that implies an unseen planet exterior to the main belt of the disk. We propose to observe the HD 181327 debris disk with ALMA to map azimuthal variations in the flux density from mm grains. When combined with our new STIS image, the ALMA observations will confirm or refute the recent collision of a Pluto mass object in the disk and reveal the true visible wavelength scattering phase function, which we will use to confirm or refute evidence for an unseen planet exterior to the belt and improve constraints on the composition of the disk. | Debris disks, Exo-planets | Disks and planet formation | 2015-08-14T00:00:00.000 |
| 3578 | 2015.1.00421.S | 0 | Polarimetric Observation of Centaurus A: Poloidally-dominated Magnetic Field vs. Toroidally-dominated Magnetic Field in the Innermost Jet | We propose band-7 polarimetric observation of the nearby radio galaxy Centaurus A. The polarimetric observation is the unique tool to investigate the magnetic field structure of the extragalactic jets. In particular, the magnetic field property in the innermost jet is a key ingredient to understand the jet formation and acceleration. However, the innermost magnetic field structure has been hardly explored so far. The major problem is that polarized emission cannot be detected in parsec scale because of strong depolarization effect at centimeter wavelengths. Mm/submm observation is essential to avoid such a depolarization and to investigate the polarized emission from the innermost jet. Our ALMA band-7 observation will firstly unveil the magnetic field structure in the innermost jet of Centaurus A. From this observation, we will distinguish whether the magnetic field is poloidally-dominated or toroidally-dominated. This is highly important to understand the role of magnetic field for the jet production since the jet production state is expected to be dependent on the magnetic field morphology based on the recent general relativistic magnetohydrodynamical simulations. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-02-03T11:33:42.000 |
| 3579 | 2019.1.00641.S | 32 | Environmental variations of the filament widths | The existence of a "universal width" for filaments in the ISM is one of the most controversial topics in the star-formation field. According to recent Heschel observations, nearby low-mass filaments present a constant width (FWHM) of ~0.1pc. On the other hand, interferometric observations demonstrate the existence of much narrower and denser filaments in more distant and massive star-forming regions with FWHMs down to ~0.03pc, only observable at ALMA resolutions. Rather than a constant and unique width, the observed differences between low- and high-mass regions suggest that filaments could present different FWHMs depending on their internal density. To address this fundamental question, we here propose to map a total 6 protoypical low-, intermediate-, and high-mass star-forming regions within the Orion complex, all mapped using ALMA Cycle-7 Band-3 observations of N2H+(1-0) as dense gas tracer. By comparing the densities, internal dynamics, and widths of entire filament populations, our goal is to obtain the first statistically characterization of the environmental variations of the filament widths in the new ALMA era. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-04-17T23:29:13.000 |
| 3580 | 2015.1.00037.S | 0 | Toward Resolving the Magnetic Flux Problem in Star Formation: Mapping Poloidal B-Field in Edge-on Disks | Poloidal magnetic field is expected in protostellar disks, if magnetic flux is dragged into the disks from star-forming dense cores. Such a poloidal field can play a key role in disk evolution and jet launching. However, direct evidence for its existence has been lacking. Here, we propose to detect and map the poloidal field in the young, edge-on, and resolvable disks in two nearby disk-jet systems, HH 212 and HH 111, using polarization observation of thermal dust emission in 345 GHz at 0.1" resolution. If detected, it would mean that some of the core magnetic flux is indeed dragged into the disks and the poloidal field can indeed play a key role in both disk evolution and jet launching. A negative result would cast serious doubt on the poloidal-field driven disk evolution and jet launching. It would also imply that the long-standing ``magnetic flux problem'' is somehow resolved at large distances beyond the disks, so that none of the core magnetic flux is dragged into the disks. This proposal is a resubmission of our accepted Cycle 2 project and can be withdrawn if that project is completed. We aim to produce the first maps of poloidal B-field in young disks. | Low-mass star formation | ISM and star formation | 2017-11-09T12:33:51.000 |
| 3581 | 2017.1.00719.S | 240 | The GLEAMing of the first supermassive balck holes in the Universe | The low-frequency radio survey, GLEAM, has opened a new window for identifying radio-loud AGN (RLAGN) during the epoch of reionisation (z > 6). To identify them, we rely on a well-proven technique allowing us to push our current sources to z 5. We select candidates from their radio steep-spectrum radio emission, a well proven technique to identify high-z RLAGN. We focus particularly our research on the GAMA-09 field, allowing to further optimise our selection, observation time and discard potential low-z sources contamination thanks to the multiwavelength information provided by the GAMA survey. We propose here to bypass the traditional framework (consisting of a succession of observations) for identification of high-z sources by using ALMA to scan B3. The discovery of even a single RLAGN at the epoch of reionisation will open up a myriad of powerful new research avenues such as probing the neutral IGM with HI absorption against the radio source but also constrain how supermassive blackholes formed at such high redshifts. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-02-18T23:28:43.000 |
| 3582 | 2018.1.01306.S | 10 | Does a bright SMG have a giant rotating gas disk? | Submillimeter bright galaxies (SMGs) are gas and dust-rich, massive galaxies and of importance as progenitors of massive early type galaxies in the local universe. Recently we discovered a bright SMG (SFR~2000 Msun/yr) with very extended molecular gas disk (40 kpc), which resides in a z=3.09 proto-cluster core. The current 0.8 arcsec mapping uncovered overall velocity gradient, which appears to be unusual giant, rapid rotating disk. But the apparent velocity gradient may be from major-merger at the current spatial resolution. Here we propose 0.2 arcsec mapping of CO(3-2) line from the SMG to finally unlock the gas dynamics and distributions. We will also observe other 3 z=3.09 SMGs in the same FoV and compare the gas properties with the giant, extended SMG, utilizing the ALMA time effectively. Thus this band-3 observation will uncover the fueling mechanism of multiple SMGs at the proto-cluster core, where the ancestors of massive ellipticals were assembling the stellar mass rapidly. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2020-12-11T00:38:34.000 |
| 3583 | 2017.1.00801.T | 39 | Radio Polarlimetry of GRB Afterglows | Gamma-Ray Bursts (GRBs) are currently being exploited as probes of the first generation of stars. Therefore, ongoing research aimed at understanding GRB progenitor stars represents one of the most pressing inquiries in modern astrophysics. Undoubtedly one of the most critical measurements is the Faraday depolarization along with spectrum evolution caused by non-energized electron, which requires the revision of the standard mass of the progenitor star. In this program, we intend to conduct linear polarlimetry at the millimeter wavelength (Band3) together with simultaneous ACA photometry (Band7), and then to consolidate the methodology to estimate the fraction of non-energized electron. The intensive studies of non-energized electron in a number of afterglows will make a revolutionary change in the GRB progenitors, because diversity of GRB afterglows is likely linking with type of progenitor stars. Linear polarizations in Band3 with the high sensitivity are essential for discovering these non-energized electrons, because the Faraday depolarization caused by the non-energized electrons suppress the linear polarization degree at a frequency of 100-1000 GHz. | Gamma Ray Bursts (GRB) | Cosmology | 2019-04-13T04:01:43.000 |
| 3584 | 2023.1.01354.S | 0 | Investigating the dynamical evolution of DSFGs | Recent studies have shown that dusty star-forming galaxies (DSFGs) at 4 < z < 5 exhibit a surprising behavior, with most of them being consistent with cold rotating disk scenarios. This contradicts expectations based on the extreme conditions in their interstellar medium (ISM). However, in order to understand if this scenario is characteristic of this population, it is crucial to build a larger sample of sources with high-quality data products, e.g. velocity and dispersion maps, covering a wider redshift range. In this regard, we propose 0.15" resolution observations of the [CII] 158um emission line in 10 gravitationally lensed DSFGs, with 2.8 < z < 3.9. This sample comprises all currently confirmed strongly lensed DSFGs and with a spectroscopically confirmed redshift, that can be observed with this setup in a reasonable time (almost doubling our current sample of source with similar quality observations). By reconstructing the [CII] line emission distribution on scales of ~300-400 pc, we will determine the global kinematics and study their evolution, while also comparing the gas distribution to that of the continuum emission, which traces star-formation on similar scales. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2025-09-03T12:46:45.000 |
| 3585 | 2015.1.00997.S | 140 | Extreme quasar feedback in the early Universe | So far there is only one single detection of a quasar driven massive outflows in the early Universe, close to the reionization epoch, at z~6. However, comparison with models have shown that in such a quasar the outflow is not powerful enough to clean the galaxy of its gas content and to prevent gas accretion from the cosmic filaments. Hence, the feedback process observed in this object seems not capable of quenching star formation as it was suggested by other scenarios. However, this quasar is not fully exploiting its potential and it could potentially drive an outflow an order of magnitude more powerful. We propose deep [CII] observations of a sample of five quasars at z~6, in compact configuration and by also exploiting ACA, to detect very extended massive outflows. The data will reveal whether other quasars in the early Universe are driving much more extreme outflows, with a kinetic power close to the maximum achievable by these systems, that could account for the quenching of star formation in massive galaxies at high-z. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-04-13T15:58:15.000 |
| 3586 | 2015.1.00779.S | 5 | Molecular gas content of massive star-forming galaxies in a galaxy cluster at z=1.46 | We propose Band-3 observations targeting CO(2-1) emissions from [OII]-selected massive star-forming galaxies in a z=1.46 galaxy cluster to investigate molecular gas content of the galaxies. The location where our targets inhabit implies that they are probably progenitors of the present-day massive galaxies in galaxy clusters. Interestingly, the galaxies are growing with star formation activity and still in intense evolutionary phase. Thus, the galaxies are one of the best targets to discuss how the cluster galaxies evolved and acquired the characteristic properties such as less star-formation activity and bulge-dominated morphology. We focus on gas reservoir, depletion timescale of molecular gas and efficiency of star formation. We compare the gas properties in the cluster galaxies with those in the field galaxies, and identify what is a key process governing the evolution of cluster galaxies. Note that even if CO emission lines are not detected from our targets, the proposed observations are deep enough for us to conclude that the cluster galaxies at z=1.46 contain less amount of molecular gas at a given stellar mass compared to field galaxies at similar redshifts. | Starburst galaxies, Galaxy Clusters | Active galaxies | 2017-08-04T20:56:50.000 |
| 3587 | 2015.1.00889.S | 5 | Inner disk, dust ring and spiral-like structures in the circumstellar disk AB Aurigae | The disk of AB Aurigae exhibits spectacular spiral patterns. However, previous explanations of the spiral formations are purely based on the morphologies due to the lack of the kinematic information. We have started SMA+PdBI+30m observations toward AB Aurigae to trace the kinematics of the spirals using CO lines with 0.4 resolution. We found that spirals traced with CO 2-1 is accreting material from the envelope following the parabolic/spiral-like trajectories well above or below the disk plane. The bases of these spirals are very close to the 1.3 mm dust ring and therefore, the material may accumulate near the edge of the dust ring. How the material accretes further from this ring toward the central disk is another question, more likely related to a tidal truncation by an unknown companion. We propose to observe 12CO, 13CO and C18O 2-1 lines, SO 5(6)-4(5) line and the dense disk using 1.4 mm continuum with 0.1" resolution. We aim at tracing the bases of the spiral structures and resolve (constrain) the size and dust properties of the inner disk. | Disks around low-mass stars | Disks and planet formation | 2017-02-25T07:51:57.000 |
| 3588 | 2022.1.00290.S | 58 | Is atomic carbon a good tracer of H2 gas?: Impacts of cosmic-ray and/or shock induced destructions of CO | Atomic carbon line emission [CI] is believed to be a good tracer for deducing the H2 distribution in galaxies and one that can be as reliable as the low-J CO line emission. However, it is not fully understood how the [CI]/[H2] abundance ratio is modified under the interstellar environment where cosmic-ray induced and/or shock destructions of CO molecules occur efficiently. We here propose to observe [CI](3P1-3P0), 12CO(J = 1-0), and 13CO(J = 1-0) line emission toward the pre- and post-shocked molecular clouds in the Galactic supernova remnant (SNR) RCW 103. We will distinguish the two effects by observing the spatial variations of [CI]/[CO] abandance ratio: the high [CI]/[CO] values due to the shock-destruction of CO can be seen only in the post-shocked layer, whereas cosmic-ray induced destructions will affect both the pre- and post-shocked clouds owing to their energy-dependent diffusions. This proposed observation will unveil the behavior of [CI] under the peculiar interstellar environments and verify its suitability as a tracer for H2. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-06-28T20:42:01.000 |
| 3589 | 2017.1.00581.S | 57 | Dense molecular gas as a test for the mode of star formation in galaxies at z=2-3 | There is mounting evidence for a more efficient mode of star formation in galaxies at z~2 compared to the present day, based on the higher star formation rate (SFR) for a given molecular gas mass probed by CO and dust. Here, we seek to verify this result by obtaining the first dense gas observations with HCN in six z=2-3 star-forming galaxies (SFGs). HCN traces high density gas, directly probing the star-forming gas within giant molecular clouds. Gravitational lensing offers us the unique opportunity to detect HCN in z~2 galaxies with normal SFR, as HCN is otherwise too faint and unfeasible to detect in these galaxies even with the sensitivity of ALMA. Combined with the rich ancillary data of the targets, we will (1) test whether the L_HCN-L_IR linear relation holds at z~2; (2) measure the dense gas fraction (L'_HCN/L'_CO(1-0)) in z~2 galaxies. The proposed observations will directly constrain how the mode of star formation varies with cosmic time and stellar mass: do z~2 galaxies behave like local starbursts or spirals, in terms of SFE and dense gas fractions? Do galaxies share the same SF physics at different z? | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2019-03-21T20:55:25.000 |
| 3590 | 2016.1.00695.S | 8 | Probing chemical heterogeneity in the nucleus of an "aged" comet | The primary volatile composition of comets provides an important link between nebular and interstellar processes, as well as clues about the formation processes of our planetary system. Without directly sampling the nucleus, we observe the emissions from the gas species in the coma to determine the composition of a comet. However the gases escaping from the thermally processed nucleus surface may not be representative of the bulk composition of the ices deep in the nucleus. Cometary outburst/jets potentially provide the opportunity to release fresh, minimally altered material from the interior of the nucleus, representing the true composition of the nucleus. We propose to use ALMA to observe an highly evolved but still active comet 2P/Encke near its perihelion, by mapping the small scale spatio-kinematic differences in the distribution of HCN, CO and CS emission in band 7 simultaneously with the most compact configuration, in order to investigate the chemical heterogeneity in the nucleus of this "aged" comet. | Solar system - Comets | Solar system | 2018-07-18T23:03:19.000 |
| 3591 | 2021.1.01366.S | 39 | Direct constraints on ionizing agents from an edge-on young circumstellar disk | Although ionization is one of the most fundamental processes behind the physics and chemistry of protoplanetary disks, and hence planet formation, it is still poorly constrained. The dominant ionizing sources are UV and X-ray radiation, short-lived radionuclides and cosmic rays (CRs), but their relative importance and ionization rate are not well known. For example, the CR ionization rate is predicted to be low due to deflection of CRs by the stellar wind, but can also be elevated in strongly accreting sources. Constraining the CR ionization rate in young embedded disks is especially important as high CR ionization rates are required for the chemical processes that can explain the low abundance of CO in more evolved protoplanetary disks. We therefore propose to observe a suite of ionization tracers (HCO+, H13CO+, DCO+ and N2D+) in the young disk IRAS 04302. The edge-on configuration of this disk allows us to directly identify the the presence of CRs and short-lived radionuclides from the molecular line images. Subsequent detailed physicochemical modeling will then allow us to quantify the ionization rate. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-02-15T09:24:45.000 |
| 3592 | 2018.1.01634.S | 54 | Chemistry Associated with the Protostellar Disk with the Youngest-Known Ringed Dust Structure | We have detected dust rings in the disk of Class I protostar IRS 63 with our Cycle 3 Band 6 continuum program 2015.1.01512.S (PI: Segura-Cox), making IRS 63 the youngest protostellar disk with evidence of multiple ringed substructures to-date. We propose for molecular line tracers of disk chemistry and kinematics around IRS 63 to simultaneously trace the impact of CO and H2O freeze-out chemistry on the ringed dust morphology of the disk and study kinematics near the centrifugal barrier. We request 6.8 total hours of Band 7 observations in two spectral set-ups with a best resolution of 0.12 (15 AU) spatial resolution and 0.3 km/s spectral resolution. Snowlines in disks are a possible way to form rings in the dust of protostellar disks. If the CO snowline is detected in the disk of IRS 63, it will be the least evolved source with detected CO disk freeze-out morphology. We will also probe the disk-envelope transition zone, the centrifugal barrier, with molecular lines known to trace chemical changes between the disk and envelope to further understand the dust structure of the disk. | Low-mass star formation, Astrochemistry | ISM and star formation | 2022-07-21T20:14:44.000 |
| 3593 | 2018.1.00366.S | 43 | Feeding and feedback in an unbiased and representative sample of AGN in the local Universe | We will map CO(2-1) in the central 3 Kpc of a representative and unbiased sample of 34 AGN in the Local Universe (D=10-50Mpc), from the 12µm all-sky sample. This is crucial to quantify the global AGN feeding and feedback and measure the time-averaged impact of these processes-the key unknown in theories of galaxy evolution. We will detect molecular outflows down to 10^5 Mo, derive outflow rates, gas reservoir masses and depletion timescales for the entire population of local AGN. We will identify the gravitational torques driving infall, and measure inflow rates. With the continuum maps we will measure dust masses, sizes and gas/dust ratios in the nuclear disks. We will observe 8 bright AGN in 5.4 hours to complete the proposed sample in our cycle 5 proposal 2017.1.00236.S, including 34 AGN (14 Seyfert 1 and 20 Seyfert 2). The final sample will be compared with archival ALMA maps of a similarly selected sample of LINERs. The legacy value comes from combining uniform CO maps for a relatively unbiased well-studied sample of bright AGN. We will identify the most suitable bright nearby AGN for ALMA high-resolution follow-up to dynamically constrain their black hole masses. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2020-11-19T00:00:00.000 |
| 3594 | 2021.1.00849.S | 52 | Isotopes as a Window into the Long-Term History of Tidal Heating at Io | Tidal heating is one of the central drivers of geological activity across Solar System satellites, and directly impacts the habitability of subsurface ocean environments. However, geological processes on active satellites rapidly erase surface signatures of their long-term thermal evolution. The jovian satellite Io is the most dramatic example of tidal heating, with its large-scale volcanism and 1 ton/second mass loss rate. Yet even for this canonical case it is not known how long the tidal heating has been active, nor whether Io's current activity level is typical of its long-term history. Isotopic ratios can provide a rare window into these questions. We propose to measure Io's isotopic fractionation by measuring the ratio of 37/35Cl in NaCl and KCl, and 34/32S in SO2 and SO. The low optical depth of the targeted lines will remove degeneracies in interpretation of past S isotope results, opening a new avenue into studying Io's history far back beyond the 1 Myr that is recorded on its young surface. | Solar system - Planetary atmospheres | Solar system | 2023-06-17T22:54:07.000 |
| 3595 | 2021.1.00186.S | 15 | The Water Trail Blazed by an Outbursting Protostar: Resolving the Water Snowline | Water is fundamental to all aspects of the star formation process and life as we know it. A key to tracing the origins of water from the ISM to the Solar System has been its D/H ratio. However, the water D/H ratio is unknown in proto-planetary disks, the expected location of planetesimal formation, because the bulk of the water reservoir in proto-planetary disks is frozen-out onto dust grains in the disk midplanes. Only the inner few AU of typical disks is warm enough for gas phase water to exist. Fortunately, young stars often undergo FU Ori outbursts, increasing their luminosity by ~100x and moving the water snowline out to 10s of AU. We propose to observe the water D/H ratio in the disk surrounding the outbursting protostar V883 Ori (d~400 pc). ALMA observations (0.03" resolution) resolved a massive disk and a water snowline of 42 au was predicted. To measure the water D/H ratio, we will observe two HDO lines (225 and 241 GHz) and one H218O line (203 GHz) at 0.1" resolution. These observations will enable us to resolve the snowline and directly measure the water D/H ratio in a proto-planetary disk, a key waypoint along the water trail. | Low-mass star formation | ISM and star formation | 2022-12-12T11:39:34.000 |
| 3596 | 2021.1.00398.S | 7 | Molecular Gas Census in a giant Lyman-alpha blob at z=3 | Lyman-alpha blob (LABs) are extended gaseous nebulae, preferentially found in overdense environments in the early Universe. The existence of plentiful amount of hydrogen on circumgalactic medium (CGM) scales makes the LABs a key field to understand galaxy formation in gas-rich, massive haloes. One of the most spectacular one is SSA22-LAB1 (hereafter LAB1), located at the z = 3.1 SSA22 proto-cluster. Recently ALMA uncovers dynamic, multiple major-mergers within LAB1, detecting [CII] and dust continuum. To improve our understanding of how the galaxy assembly occurs, involving surrounding matters, information of the molecular gas reservoir is essential. Here we propose deep CO(3-2) mapping of SSA22-LAB1 in ALMA Band 3 to uncover molecular gas reservoirs within the giant Lyman-alpha nebulae. Our immediate objectives are (i) to derive molecular gas mass for individual galaxies and uncover gas mass assembly during the hierarchical merger phase, (ii) to diagnose ISM conditions and uncover how the peculiar environment influence the ISMs, and (iii) search for molecular CGM. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-08-03T20:05:25.000 |
| 3597 | 2015.1.01171.S | 12 | Environmental effect on the gas properties of star-forming galaxies in the COSMOS "Wall" at z~0.73 | The properties of local galaxies depend on their cosmic environment: star formation (SF) activities are quenched and morphologies change when galaxies enter dense regions. While the mechanisms at the origin of these transitions remain unknown, observations point towards a critical cosmic time, 0.5 | Galaxy Clusters | Cosmology | 2018-03-15T13:52:10.000 |
| 3598 | 2021.1.01150.S | 304 | AGN-galaxy interplay through multiphase outflows and feedback | High velocity ( 1000 km/s) and extended AGN-driven outflows are frequently detected in local and high-redshift galaxies, at different luminosities, in ionized, neutral and molecular gas phases. However, despite the huge improvement in the knowledge of AGN-driven outflows, most of the samples considered by these studies are incomplete due to biases against absorption in the optical/soft X-ray bands. Therefore it has been difficult to place the outflow signatures of galaxy populations in the context of both obscured and unobscured AGN. Which is the role of AGN with respect to star formation in their hosts still unclear. To really understand the AGN feedback process, we need to consider a representative sample and test the effects of outflows in their different gas phases based on the same targets. Here we propose a 100 pc resolution CO(2-1) observations of hard X-ray selected AGN with resolved ionized outflows from MUSE data analysis. We aim to test AGN feedback effects by studying how the different gas phases of outflows affect their hosts. Our ALMA sample will provide the first and large high resolution census of multiphase outflows for the least-biased sample of nearby AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2023-06-30T18:48:00.000 |
| 3599 | 2016.1.01426.S | 96 | High-resolution mapping of molecular gas in starbursts at z ~ 1.5 | We propose to determine the molecular gas distribution with ALMA at high resolution of three starbursts (Herschel-detected) galaxies at z ~ 1.5 using the CO 5-4 emission line. A spatial resolution of 0.1-0.25" enables us to derive kinematic and morphological information on physical scales of 0.8-2 kpc. Our galaxies have total CO fluxes (hence gas masses) from previous ALMA observations that may indicate a higher efficiency of converting gas to stars as responsible for their elevation well-above the star-forming main sequence at z ~ 1.5. This sample is selected from a spectroscopic near-infrared survey of star-forming galaxies in COSMOS with Subaru-FMOS that provides dust-corrected Halpha-based SFRs, metallicities, ionization conditions, and dust extinction using rest-frame optical emission lines. These ALMA observations will further elucidate the nature of sites of extreme star-formation within individual starbursts including their gas density, dust content and star formation efficiency. | Starbursts, star formation | Active galaxies | 2018-09-28T11:18:01.000 |
| 3600 | 2019.1.00994.S | 84 | Why is there a 400 K cloud of C3H+ in M17SW? | We have recently begun to investigate the utility of the new molecule C3H+ as a unique tracer of UV-illuminated gas in the ISM. Our first-look observations in the M17 SW PDR reveal two entirely different populations of C3H+. One behaves nearly exactly like the first detection of the molecule in the Horsehead PDR, tracing a line of excitation across the PDR front with very cool (sub-thermal?) temperatures of ~30 K. The other does not appear to trace a particular front, is at least 400 K, and may be caused by either an obscured radiation source or an undetected shock event. Here, we propose follow-up observations of this region to understand the apparently aberrant behavior of this potential new tracer species. These observations are critical to understanding whether or not C3H+ can be an effective tool for probing UV-dominated regions in the ISM. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2021-04-21T21:49:46.000 |
| 3601 | 2023.1.01197.S | 0 | ALMA Proper Motions in the B335 Jet: Connect an Ejection Event to an Accretion Burst. | We will observe B335 in the CO transitions at 1.3 mm to determine the proper motion of an ejecta associated with a luminosity burst. B335 has undergone strong luminosity evolution over the last 6 years, with an increase of a factor of 5-7 starting in 2017. Previous CO observations showed a high velocity structure in the blue outflow lobe. Recent JWST observations found a region of strong near-infrared CO band emission farther from the protostar. Plausible ejection velocities allow these to be the same structure, but we need new ALMA observations to definitely establish this association and measure the proper motion. These observations will provide a connection between accretion surges and outflow structures that can be used to trace the history of episodic accretion in this and other sources. | Outflows, jets and ionized winds | ISM and star formation | 2025-02-26T21:02:08.000 |
| 3602 | 2022.1.00343.S | 0 | Systematically Measuring CO Emission of Double-Barred Galaxies | We propose to initiate a systematic and reliable study on molecular gas in double-barred galaxies. The inner bar in double-barred galaxies is one of the mechanisms to drive gas inflow to fuel active galactic nuclei. However, it is still unclear whether and how much gas is needed to maintain a long-lived inner bar. Previous studies were unable to provide reliable results due to the difficulty to identify true double-barred galaxies and inadequate sensitivity and spatial resolution to measure the gas mass in the entire galaxy as well as in the inner bar region. To remedy this situation, we propose to obtain the CO line emission of ten double-barred galaxies which have been confirmed to have a unique feature in the stellar kinematics called sigma-hollows. This feature identifies them as true double-barred galaxies. Using these ALMA observations, we will be able to provide reliable constraints of the gas mass on theories to shed light on the formation of double-barred galaxies. Our data will also provide important information for future studies to investigate the gas properties in double-barred galaxies, such as the gas inflow rate, which require higher spatial and velocity resolution. | Surveys of galaxies | Galaxy evolution | 2024-10-26T19:51:13.000 |
| 3603 | 2011.0.00217.S | 0 | Globular cluster formation: caught in the act | Clusters are the building blocks of galaxies and the nurseries of most stellar systems. Despite their importance, even the fundamental question of whether a single mechanism can describe cluster formation across the mass range from open clusters to globular clusters remains unclear. Answering this question requires observations of a cluster's natal dust and gas well before the onset of star formation. We have identified an extreme molecular cloud that appears to be on the verge of forming a massive cluster. This cloud, G0.25+0.02, is very cold, massive, and dense with no obvious star formation and shows tantalizing evidence that it is highly substructured and, thus, may be undergoing hierarchical fragmentation. Using the ALMA early science extended configuration we aim to obtain a ~3 x 1 arcmin mosaic of the dust continuum and molecular line emission across this cloud at 90 GHz. These observations will reveal the location, mass, and kinematics of the small-scale fragments within the cloud allowing us to distinguish between competing cluster formation models. These observations can only be achieved with the order of magnitude improvement in sensitivity and dynamic range provided by ALMA. Determining whether clusters form via a single mechanism across the entire mass range has profound implications: if confirmed, this implies our knowledge of nearby cluster formation can be used as framework to understand star formation across cosmic time, back to globular clusters ~10Gyr ago. We speculate that the cloud G0.25+0.02 may represent the precursor to a modern day globular cluster. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2013-09-07T18:53:00.000 |
| 3604 | 2019.2.00052.S | 60 | Systematically Measuring CO emission of Double-Barred Galaxies | We propose to initiate a systematic and reliable study on molecular gas in double-barred galaxies by using ALMA. The inner bar in double-barred galaxies is one of the mechanisms to drive gas inflow to fuel active galactic nuclei. However, it is still unclear whether and how much gas is needed to maintain a long-lived inner bar. Due to the problems of identifying true double-barred galaxies and having high sensitivity and enough spatial resolution to measure gas mass in the whole galaxy and in the inner bar region, previous observations have difficulty to provide reliable results. Therefore, we propose to obtain CO observation of six true double-barred galaxies which are confirmed by having a unique feature of double-barred galaxies, called sigma-hollows. Using ALMA measurements, we will be able to provide reliable constraints of the gas mass on theories to shed light on the formation of double-barred galaxies. Besides, our data will also provide important information for future studies attempting to investigate the gas properties in the double-barred galaxies, such as the pattern speed of the inner bar and the gas inflow rate, which requires higher spatial and velocity resolution. | Surveys of galaxies | Galaxy evolution | 2021-04-08T07:11:30.000 |
| 3605 | 2021.1.01075.S | 16 | The ionisation fraction in embedded outflows: TMC1A | Outflows from young stars are ubiquitous in star formation. Indeed, in the current paradigm, they are an expected natural consequence of star and disk formation. It is natural to then ask why, where, when outflows exist and how they function. Although the why (angular momentum removal) is well-understood, and ALMA has recently helped answer where and when, the how still remains heavily debated. It is well-established that outflows from young stars are magnetically-driven. One of the fundamental parameters that controls the launching is then the ionization fraction (which sets the coupling between gas and mag. field). We propose to derive the value and spatial variation of the ionization fraction on scales of ~5-200 au in the outflow of TMC1A. We will target HCS+ and H3O+, which are direct tracers of the ionization fraction. By combining these observations with chemical+magnetohydrodynamical simulations, we can provide a direct link between observations and physical conditions in outflows. This will allow us to draw conclusions on how efficiently the TMC1A outflow is extracting angular momentum, and if the outflow is affecting the structure of its parent disk. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2023-01-20T15:34:47.000 |
| 3606 | 2019.1.01124.S | 81 | Which way does it go? Molecular gas in multi-spin stellar counterrotator galaxies | We propose observations of CO in four nearby early-type galaxies that each contain two counterrotating stellar disks. These "stellar counterrotator" galaxies are unusual but not extremely rare, making up about 4% of local early-type galaxies. But it's not clear how they formed. We already have detailed stellar and ionized gas kinematics in the inner few kpc of our targets, along with stellar populations and star formation histories. As molecular gas is the raw material from which stellar disks must grow, CO kinematics will help to distinguish between two basic types of formation scenarios for these unusual galaxies: via gas accretion or via major merger. Thus, these observations will pin down the (possibly different) formation mechanisms for all of the known gas-rich or dusty stellar counterrotators from the Atlas3D survey. As Atlas3D is a complete volume-limited survey, this will allow us to make quantitative comparisons to the formation rates predicted by late gas accretion and correctly-orientated major mergers in modern cosmological simulations. | Early-type galaxies | Galaxy evolution | 2021-03-10T11:42:04.000 |
| 3607 | 2016.1.01609.S | 205 | Physical properties of massive star forming clumps in the Carina Nebula | The relative importance of the mechanisms that shape the internal structure of the star forming clouds is one of the most important questions in the star formation community. The extraordinary capabilities offered by ALMA will allow us to obtain detailed map of the dense gas down to size scales ~0.03 pc, adequate to resolve the structures associated to dense cores and filamentary structure. We propose to make of use of these unprecedented capabilities to map the dense gas in two significantly different clouds located in our nearest rich region of star formation, the Carina Nebula. We will use these maps to investigate the role that external pressure plays on determining the densest components inside the diffuse medium in these clouds. The stability status of the identified structures will be used to assess whether these are supported by external pressure, and at which scale the gravity becomes the dominant force. Detailed comparison of the distribution of the dense gas and the location of young stellar objects will shed light on the dependence of the star-formation threshold on the external pressure in these clouds with different level of impact of stellar feedback. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-02-23T08:39:19.000 |
| 3608 | 2016.1.00203.S | 142 | Tracing evolution of giant molecular clouds in the Large Magellanic Cloud | We classified the GMCs in the Large Magellanic Cloud into three types according to the activities of massive star formation, corresponding to the evolutional sequence of the GMCs. The LMC molecular clouds are likely to be affected by the higher ionization degree and smaller cooling rate as a consequence of low metallicity in the LMC, and it is tempting to speculate that there is a link between populous clusters and the starless GMCs. Our Cycle 1 program mapped five GMCs of different GMC types to resolve molecular cloud structures at sub-parsec scales in 13CO(1-0) and showed that the molecular clouds consist of many filamentary/clumpy structures with large velocity differences. Here we propose to follow-up on the five GMCs to determine the physical properties more precisely by resolving filamentary and/or clumpy structures with an order of magnitude smaller beam area. The correlator setup at Band 6 including CO lines is one of the best tools to investigate the cloud properties as well as indications of star formation. These observations will lead to the understanding of the possible origin of high activities of formation of massive stars and clusters in the LMC. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2019-05-02T00:00:00.000 |
| 3609 | 2016.1.01565.S | 18 | The Fine Structure of an Extreme, Lensed Starburst Galaxy at z=5.7 | We propose to observe a full diagnostic suite of five far-IR fine structure lines in an extraordinary starburst galaxy at the end of cosmic reionization. Through the power of gravitational lensing, our observations will measure the metallicity, radiation field, density, kinematics, and AGN effects with effective resolution of a few hundred parsecs, which has only been possible to date in the nearest star-forming galaxies. SPT0346-52, at z=5.7, already has high-resolution maps of the dust continuum and low-J CO emission, as well as integrated measurements of mid-J CO, [CII], and full radio-to-IR SED coverage. These observations effectively complement Herschel studies of local ULIRGs, and extend the study of these lines to the first Gyr of cosmic history. The high sensitivity, high resolution studies made possible by ALMA will address several key questions about the first stages of galaxy evolution, including the production of heavy elements, stellar and AGN feedback mechanisms, the energetics of the ISM, and the dynamics of the first galaxies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-09-18T21:01:26.000 |
| 3610 | 2022.1.00840.S | 10 | The Most Sensitive Search for Magnetic Fields in a Solar Nebula Analogue | The search for magnetic fields threading protoplanetary disks has been a key science driver for ALMA, owing to the critical importance magnetic fields play in the evolution of protoplanetary disks. The use of continuum polarization has, however, proven to be limited owning to a multitude of polarization mechanisms unrelated to magnetic fields identified as the likely cause of the observed polarization. Molecular line polarization appears to be more uniquely related to magnetic fields, but several challenges in detecting them (beam dilution and cancellation from optically thin emission tracing opposite sides of the disk) suggest that the upper limits placed on the strength of the magnetic field could be underestimate by at least a factor of 10. We propose here a novel method to bypass these issues and instead detect a magnetic field in TW Hya purely by the broadening of emission lines due to Zeeman splitting. This is unaffected by the aforementioned issues and will allow us to detect a 10 mG field out to 150au in TW Hya at a 3 sigma significance. In addition to placing unique constraints on magnetic fields, this allows us to calibrate the non-detections found in the literature. | Disks around low-mass stars | Disks and planet formation | 2024-02-06T16:55:04.000 |
| 3611 | 2019.1.01178.S | 58 | Why star formation is suppressed in green valley galaxies? | Green valley galaxies are galaxies with specific star formation rate in between the star-forming main sequence and the quiescent population. They are excellent targets to probe the quenching processes and to understand the migration from the star-forming to the quiescent phase. In our previous ALMA programs (Cycles 3,5,and 6), we have observed 25 green valley galaxies in CO(1-0), selected from an integral field unit (IFU) survey of nearby galaxies, MaNGA. Although these green valley galaxies still hold a significant amount of CO gas, their star formation efficiency (SFE) has been significantly reduced. To investigate whether the low SFE is caused by the lack of denser molecular gas or not, we propose to observe HCN(1-0) in Band 3 for three green valley galaxies (and two main sequence galaxies for comparison), which have high CO-based gas fractions but extremely low SFE. We will study the HCN/CO ratio and HCN-based Kennicutt-Schmidt relation to understand the gas properties of green valley galaxies. Furthermore, the spatially-resolved data will also enable the study of the quenching pattern (inside-out, outside-in, or global quenching) to constrain the quenching mechanism(s). | Starbursts, star formation | Active galaxies | 2021-02-22T03:35:59.000 |
| 3612 | 2013.1.00350.S | 3 | Haro11: solving the mystery of star formation without cold gas | This proposal is designed to address two major issues in understanding the ISM properties of low-metallicity starburst galaxies: (1) the presence of a submillimeter emission excess, the origin of which still remains unknown; (2) the difficulty to measure the molecular gas reservoir, as CO is more prone to photodissociation by hard radiation fields than H2. We propose band 3, 6, and 7 observations of the continuum and CO lines to resolve, at 1'' , the cold ISM of the low-metallicity starburst Haro11. With vigorous star formation, bright far-infrared lines (including [CII]157um from our Herschel survey), Haro11 shows a prominent submillimeter excess, and little HI and CO, therefore standing as an outlier from the Schmidt-Kennicutt law. It is the best local case study to look into the low-metallicity ISM under extreme conditions, serving as a template for high-redshift galaxies. The continuum data will localize the component which gives rise to the excess and place constraints on its origin. The line data will enable us to probe spatially the CO excitation and physical conditions (densities, filling factors, etc.), and to determine, with C+, the total molecular gas reservoir. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2016-11-02T10:53:03.000 |
| 3613 | 2012.1.00374.S | 1 | The [CII] Line Study of Star-forming Galaxies in the Epoch of Cosmic Reionization | Detecting galaxies from the local to the highest redshift Universe, including the epoch of cosmic reionization at z >6, and characterizing their star formation activities and physical properties are obviously a key issue to understanding the formation and evolution of galaxies as well as disentangling the relationship between the diverse populations of galaxies. While star formation and dynamics of low-z galaxies have been well studied using the CO lines as a tracer, those of high-z galaxies have not due to their faintness.Meanwhile, the ionized carbon 158 micron [CII]line can be a powerful alternative to detect high-z galaxies, because it is the strongest cooling line of interstellar medium (ISM) in galaxies and observable at submm/mm when redshifted to z >6. The ALMA can detect high-z [CII]line only in a few hours and resolve galaxies in this line emission on a few kpc scales, enabling to probe obscured star formation and constrain sizes, dynamical masses and physical properties of ISM in early star-forming galaxies at the epoch of reionization for the first time.Here, we propose the ALMA [CII]line observation of star-forming galaxies at z >6. We particularly propose to target three galaxies at z=6.96, 7.109 and 7.215 discovered to date, because they are spectroscopically confirmed highest-class redshift objects in the epoch of reionization and we have a lot of information about these galaxies that can be compared with the ALMA observations. Using them as probes, we will (1) reveal the relation between high-z and local star-forming galaxies, (2) estimate obscured SFRs and state of reionization at z~7-7.2, (3) investigate the morphology, dynamics and physical properties of z~7-7.2 galaxies, and (4) to constrain the physical states of ISM in z~7-7.2 galaxies. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2015-08-20T17:09:11.000 |
| 3614 | 2021.1.01246.S | 58 | Spectroscopic identification of candidate overdensity regions of H-dropout ALMA galaxies behind two lensing clusters | We propose to obtain spectroscopic redshifts for multiple-image (i.e., lensed) H-dropout ALMA 1.2-mm-selected sources behind 2 lensing clusters by conducting band-3/4 spectral scans of CO/[CI] at RXC J0032 and band-7 scan of [CII] 158 um at ACT-CL J0102. They are apparently luminous (S_1.2mm = 1-9 mJy) but intrinsically sub-mJy sources after correcting their magnification. And more importantly, their 1.2mm/3.6um flux ratios or constraints from mass models suggest that they reside in an overdensity region or a galaxy group at z~4. The immediate goal is to spectroscopically confirm the estimated multiple-image assignments and the presence of such high-redshift clusters of forming massive galaxies, which will offer an exceptionally unique laboratory for further detailed studies of massive galaxy formation and its relation to the large-scale structures. Specifically, we will (1) characterize the overdensity regions by investigating redshift and spatial distribution of member galaxies in the source plane, (2) obtain physical quantities (T_dust, M_dust, M_gas, etc.) with improved accuracy, and (3) study their relation to the putative compactness of near-infrared faint dusty galaxies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2023-06-03T08:49:03.000 |
| 3615 | 2015.1.01259.S | 5 | Detecting H2O Snowline of a Protoplanetary Disk | We propose to observe the H2O line at 321GHz (ALMA band 7) with high velocity resolution towards a protoplanetary disk around Herbig Ae star, HD163296, to detect its H2O snowline spectroscopically. Water exists in gas-phase inside the H2O snowline, while it is frozen out on grains outside. Observationally measuring the location of the snowline is crucial to understand planet formation process since the H2O snowline is thought to divide the regions between rocky and gaseous planet formation. It will also give us information on how water was delivered to Earth. The target line that traces the location of the snowline was selected carefully on the basis of our detailed physical and chemical model of disks, since water vapor exists not only inside the snowline but also in the outer disk. The profile of the line emission from a disk represents its Keplerian rotation velocity and gives us information on the line emitting region. ALMA observations with high spectral resolution and high sensitivity make it possible to measure the location of the snowline spectroscopically for the first time and give us essential information on the planet formation process and the origin of water on Earth. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2018-03-15T08:07:39.000 |
| 3616 | 2016.1.00895.S | 17 | Robust estimates of the Molecular Hydrogen Mass in high-redshift Luminous Galaxies: Measurements of HF and CH | We propose to observe two optically thin molecular emission lines, the Hydrogen Fluoride, HF and the methylidyne radical, CH, in IRAS Z21293-0154, an Ultra Luminous Infrared Galaxy (ULIRG) at z=0.73. These molecules have column densities very well correlated to the molecular hydrogen column density down to low optical extinctions, and can provide the most accurate estimates of the molecular hydrogen, H2, content in high-redshift galaxies. These measurements will allow us to: (a) test the accuracy of widely used tracers, such as Carbon Monoxide and dust mass, which suffer from systematics that are very hard to characterise; (b) study the velocity field of the interstellar medium of an ULIRG with realiable H2 tracers; (c) constrain the ISM physics included in galaxy formation simulations. This proposal would prove the feasibility of HF and CH as reliable and robust tracers of H2, which can then open a whole new field of studies of high-redshift galaxies using ALMA. | Starburst galaxies | Active galaxies | 2018-05-01T19:36:30.000 |
| 3617 | 2019.2.00117.S | 64 | Mapping the chemistry of Io's neutral clouds and plasma torus | Jupiters moon Io is the most volcanic object in the solar system, emitting hundreds to thousands of kilograms-per-second of sulfur dioxide and other volcanic gases into Ios near space environment. The material spreads - via diffusion, charge exchange and other processes - to make up a complex neutral cloud that forms a torus around Jupiter, centered along Io's orbit. The material dissociates into SO, sulfur and oxygen atoms in various states of ionization and the ionized material is picked-up to corotate with Jupiter's magnetic field, forming a torus of relatively fast-moving plasma. The dynamics and composition of the neutral and plasma torus is an exciting area of research that we propose to study by conducting the first mapping observations of molecular material in Io's torus including SO2, SO, 34-SO2 and SO+. Our proposed work will provide insight on the chemical interactions between the molecular material originating from Io and the plasma left over from its previous revolutions. Tracing the extent and movement of sulfur between Io and Europa has applications to astrobiology and future missions to the Jovian satellites as well as the currently active Juno and Hisaki missions. | Solar system - Planetary atmospheres | Solar system | 2023-05-16T00:00:00.000 |
| 3618 | 2012.1.00116.S | 4 | Close-up of a Globule in the Helix Nebula | High resolution imaging has shown that the Helix, one of the nearest planetary nebulae, is composed of a spectacular array of thousands of comet-like globules. Their origin is controversial, but they are known to consist of small, dense condensations of molecular gas with planet-like masses. We propose to make the first resolved observations of the molecular gas deep inside a globule of the Helix. Our observations in 12CO and 13CO (2-1) will probe the internal structure and kinematics of the core in unprecedented detail. The results will provide crucial information for evaluating theoretical models of the origin and evolution of these enigmatic objects. Keywords: Evolved stars - Shaping/physical structure | The Sun | Sun | 2015-11-13T13:46:32.000 |
| 3619 | 2018.1.01754.S | 15 | From Dust till Dark II: Dissecting SMM J0658 the brightest strongly lensed galaxy behind the Bullet Cluster | We propose to observe SMM J0658 (z=2.778) the brightest lensed submm galaxy behind the Bullet Cluster at 0.2" resolution in band 3. The exceptional lensing circumstances (that cause this source to split into four distinct images with differential magnification up to 50), together with the superb angular resolution and sensitivity of ALMA makes it possible to probe the conditions of the cold ISM as well as characterize the kinematics of a SMG at sub-kpc resolution. We have obtained previous ALMA cycle 3 observations to locally improve the Bullet Cluster lens model to account for differential magnification, which allowed us to explore the reconstructed source (a region of ~4.6 kpc) with a resolution of 620 pc. SMM J0658 shows a clumpy-like sub-kpc structure (with sizes comparable to the synthesized beam size) in its CO maps and a rotation curve which extends up to 1.6r_1/2. This proposal seeks higher resolution and higher signal-to-noise to further investigate the rotation curve at larger radii near the caustic with a mu>50, and to probe the physical conditions at sub-kpc resolution of a dusty star-formation galaxy at z>1. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2023-06-30T19:19:23.000 |
| 3620 | 2016.1.00039.S | 131 | Measuring the Masses of VeLLOs | Understanding how protostars gain their mass requires knowledge of their current masses and mass accretion rates, quantities that to date have only been probed indirectly through protostellar luminosities. At the extreme end of the protostellar luminosity distribution are VeLLOs (Very Low Luminosity Objects), protostars with luminosities less than or equal to 0.1 Lsun. VeLLOs, with luminosities >10x below those expected for accretion onto even substellar objects, are challenging to understand. They must feature some combination of very low masses and very low mass accretion rates, but as neither quantity has been directly measured to date, their physical nature remains ambiguous. We propose high-sensitivity, high-resolution C18O (2-1) observations to characterize Keplerian rotation in the disks surrounding these protostars, definitively measure their masses, and test recent theoretical predictions that VeLLOs must be extremely low-mass protostars. We will also obtain simultaneous observations of 13CO, 12CO, SO, H2CO, and the continuum to obtain alternative disk tracers, constrain recent outflow activities, and study the density structures on very small scales. | Low-mass star formation | ISM and star formation | 2018-01-25T14:11:00.000 |
| 3621 | 2017.1.01100.S | 382 | An Unprecedented Census of the Molecular ISM in Starburst Galaxies at the End of Cosmic Reionization | We propose a full molecular line inventory in Bands 3 and 4 of four of the highest known redshift dusty starburst galaxies accessible by ALMA, at z~5.7, close to the end of cosmic reionization. Our previous ALMA spectroscopy in two DSFGs at similar redshifts, show striking results, anticipating a new era for molecular ISM studies in high-z galaxies. We expect to detect more than 40 lines of 13 molecular species in each object, tracing the full range of excitation conditions, heating mechanisms, outflow and dynamical signatures, and chemical enrichment pathways. At these rest frequencies, our observations will match and even exceed the sensitivity of local starbursts observed by Herschel/SPIRE. By exploiting high-resolution ALMA 870um continuum observations, low- and mid-J CO observations with ATCA and ALMA, [CII] emission from APEX, and full optical-to-radio SED coverage, these observations will stand as the definitive view of the ISM conditions in these objects, serving as an effective comparative study to local starbursts (e.g. Arp220) and intermediate-redshift analog systems (e.g. the Eyelash). | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-04-27T14:28:30.000 |
| 3622 | 2016.1.01032.S | 36 | Unraveling the shock structures inside Water fountain nebulae | Post-Asymptotic giant branch sources with high-velocity 22GHz H2O maser emission tracing their bipolar outflows are known as Water fountain nebulae. The fact that the 22GHz H2O maser emission is detected tracing the bipolar structures of these sources could indicate that their high-velocity outflows are still propagating troughout the relic circumstellar envelopes. Our goals are the detection of continuum and 321GHz H2O maser emission using ALMA band 7 towards three water fountain nebulae. Reports from single dish observations towards Water fountain nebulae have shown spectral features of the 321GHz maser transition covering velocity ranges >100 km/s. Band 7 observations towards the proposed sources will allow us to map for the first time the 321GHz H2O maser emission in Water Fountain nebulae. This will allow us to distinguish between two scenarios for the jet launching mechanism. Moreover, the detection of a dust torus structure around these sources would be an important indicator of the nature of the mechanism responsible for the collimation of the bipolar structures observed towards these enigmatic sources. | Post-AGB stars | Stars and stellar evolution | 2018-10-06T00:13:21.000 |
| 3623 | 2018.1.01231.S | 0 | How quiescent are quiescent galaxies? | How many quiescent galaxies that are selected using optical and infrared color-color cuts are dusty galaxies? To answer this question deep far-infrared/submillimeter observations are needed to unambiguously determine the dusty star formation in and around ``quiescent'' galaxies. Here we propose a pilot study to obtain deep ALMA band 7 observations of a carefully selected, well-defined sample of quiescent galaxies at z=2.5-3.0 in the COSMOS field. We aim to unambiguously determine the obscured star-formation rate of our target sample to a detection limit that ensures quiescence, even if they are not detected. With our proposed observations we will: determine the exact fraction of color-selected quiescent galaxies that are in fact dusty star-forming galaxies; redefine the color cuts used to seperate star-forming and quiescent systems; and derive the stellar mass function of truly quiescent galaxies at z=2.5-3.0, where significant discrepancy remains between model predictions and observations. | Galaxy structure & evolution | Galaxy evolution | 2020-08-28T20:25:31.000 |
| 3624 | 2019.2.00238.S | 36 | Characterization of the Disks Around Dippers Identified by TESS | We propose for ACA observations in Band 7 to obtain the first characterizations of the circumstellar disks around 15-150 Myr-old ``dipper" systems identified by the recently launched TESS spacecraft. These dippers provide a new opportunity to study an important but poorly explored epoch of planet formation between the protoplanetary disk phase and mature exoplanet system stage, ultimately allowing us to constrain the dynamics of the final phase of rocky planet formation like that which produced the inner Solar System. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2022-10-28T23:26:37.000 |
| 3625 | 2019.1.01566.S | 17 | Deep into the nucleus of a protobinary system: mass accretion and orbital evolution caught in the act | The dynamical interactions between a young binary system and the circumbinary disk around them are dictated by the accretion process of the disk material into the stellar components. However, the lack of molecular line observations at a few au hampers a detailed study on the kinematics predicted by models. Our team has high spatial resolution (~7 au) observations of the disk in the Class I object BHB07-11. The continuum data reveal an impressive structure of a binary system connected to narrow filaments. We propose a follow-up project focused on molecular line observations at similar resolution. We have selected lines that comprise all the excitation conditions expected to be found in the system: warm/hot (30 < Eu < 300 K) and dense (n > 1e6 cm^-3) gas. We will use high velocity channels to search for hints of infalling streams coupled to the dust filaments. We also include shock tracers to study the protostar-filament interaction zone and high excitation methanol lines to probe the presence of warm gas. Finally, we will map the continuum emission to obtain the dust distribution at higher frequency than our previous data. | Disks around low-mass stars | Disks and planet formation | 2022-09-27T14:50:22.000 |
| 3626 | 2019.2.00040.S | 100 | Extended Dust Profile of z~2 Cluster-Lensed Submillimeter Galaxies | As the most vigorously star-forming galaxies around redshift 2, submillimeter galaxies (SMGs) are generally found to host compact dust continuum with a half-light radius (Re) of ~2 kpc. After rapidly depleting their gas within ~100 Myr, SMGs are believed to evolve towards compact quiescent galaxies. Our previous ALMA program revealed a population of low-surface-brightness SMGs with extended dust profile (Re up to 3.7"; ~7 kpc lensing corrected). These features are consistent with galaxies quenching from the inside out. To directly capture the star formation cessation and dust depletion/dispersal of these short-lived starbursts, we propose to observe 12 cluster-lensed SMGs with ACA at Band 7. Specifically, with the critical low-spatial-frequency uv-coverage of ACA, we will (1) discover more SMGs with extended dust profile, and (2) deliver the first statistics of stellar and dust properties in these z~2 SMGs at their final stage. Combined with obtained Herschel and Spitzer data, this multi-wavelength census will unambiguously reveal the disappearance of compact dust structure at the end stage of SMG, building up the evolutionary picture for the most massive galaxies at z~2. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-12-21T15:54:47.000 |
| 3627 | 2012.1.00122.S | 2 | Rotation and Proper Motion of the HH 212 Jet | Protostellar jets are believed to be launched from accretion disks around protostars, carrying away extra angular momenta from the disks, allowing material to fall onto the protostars. Their launching radius and thus model (i.e., x-wind v.s. disk-wind models) are still uncertain but can be determined from their rotation and velocity, which can be measured with ALMA's unprecedented sensitivity and resolutions. HH 212 is a nearby (400 pc) well-defined Class 0 protostellar jet in Orion. It is almost in the plane of the sky, ideal for jet rotation and proper motion (thus velocity) measurements. We have mapped it at up to ~ 0.35" resolution with the SMA, with tentative detections of jet rotation and proper motion. Since the jet is still not resolved across the jet axis, here we propose to map it again with ALMA to resolve it at a higher angular resolution in (1) CO J=3-2 and SiO J=8-7 and (2) CO J=6-5 and SiO J=16-15, in order to confirm and resolve the jet rotation and to measure the proper motion. If confirmed, the jet rotation will be the first one detected in star formation, hugely impacting the community. Our Cycle 0 proposal was accepted to observe this jet at the same resolution as in our SMA data in order to confirm our measurements. So far no data yet. Since the jet will not be resolved in Cycle 0, here in Cycle 1, we propose to observe it at twice as high of an angular resolution in order to resolve it. We aim not only to confirm, but also to resolve the jet rotation in order to better determine the jet launching model. In particular, we aim to check if the rotation velocity increases toward the jet axis as predicted in the current models. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2016-11-17T08:13:25.000 |
| 3628 | 2023.1.00358.S | 0 | DSHARP's Relics: Connecting pebbles and planetesimals in 10 Myr circumstellar disks to planets and dust | Our goal is to investigate the evolution of circumstellar dust in the complete sample of 10-12 Myr Upper Sco members that will evolve into Sun-like stars on the main sequence. This is a key epoch that can place strict limits on the presence of pebble and planetesimal belts, and differentiate between circumstellar disk evolutionary pathways towards the main sequence systems dominated by planets and Kuiper Belt analogs. Deep ALMA imaging is required for 43 of the 45 members in this sample, in order to study the evolution of the descendants of massive, large protoplanetary disks, the relics of those observed in the DSHARP survey (with r>30au), and their more compact disk counterparts in the context of new model predictions (Najita+22). Our proposed survey is 3x deeper than any previous surveys of Upper Sco, and with 0.41'' resolution is sufficient to resolve discs with fractional luminosities f>1e-4 and radii >30au. At no cost to our setup (for free) will also search for the CO J=3-2 spectral line to constrain CO gas presence, and the gas dispersal status of our sample. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2025-11-08T21:44:10.000 |
| 3629 | 2015.1.00175.S | 30 | Chemistry in the Brightest Face-On Starburst Galaxy | M 83 is the best ALMA target to study spatially-resolved chemistry in the nuclear region of a starburst galaxy. This is because of its proximity, face-on configuration and brightness. It has been proposed from near infrared/optical/UV observations that the gas flowing through the bar into the circumnuclear ring can induce active star formation.This creates an age gradient of stars along the circumnuclear ring. We propose to observe molecular tracers to examine whether chemical composition along the circum-nuclear ring can be used to probe such a time difference in star formation.In several frequency settings in Band 3, 6, and 7, we will map molecular tracers of shocks, photon-dominated regions, dense cores, at the GMC-scale. Our chemical diagnostics can reveal the star formation sequence even in regions of high obscuration where light at other wavelengths cannot convey the information. This dataset will also serve as a chemical template in the circumnuclear ring of a starburst galaxy with much better spatial information, sensitivity, and chemical complexity than previous studies. | Starbursts, star formation | Active galaxies | 2018-02-18T00:00:00.000 |
| 3630 | 2022.1.00381.S | 12 | Resolving the dynamics of quasar host galaxies at cosmic noon | The gas kinematics of quasar host galaxies convey a wealth of information, such as their distribution of mass, energy injection from stellar or AGN feedback, and recent mergers. Thus far, there have been no sufficiently high-resolution studies of quasar host galaxies at z>1 that are able to disentangle dynamically cold discs from mergers. We propose observing two strongly lensed quasar systems at sufficient resolution and sensitivity in CO (3-2) line emission. Using a novel fitting technique that combines lens and 3D kinematic modelling, and methodology to distinguish discs from mergers and outflows, we will definitively characterise the gas kinematics of these galaxies. We envision this as a pilot project that will initiate a multi-wavelength study of lensed quasars to investigate the co-evolution of galaxies and their black holes at the peak of cosmic star formation and black hole accretion. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-06-19T17:20:40.000 |
| 3631 | 2021.1.00552.S | 3 | The role of magnetic fields in the formation of young massive clusters | We want to establish the role of the magnetic field (B-field) in the formation of young massive clusters (YMCs). YMCs are gravitationally-bound stellar systems with masses and densities orders of magnitude larger than typical open clusters, but comparable to those in globular clusters and extragalactic super star clusters. Out of the very few YMC progenitor candidates known to date, SgrB2(N) stands out as the only YMC in the making. Previous ALMA observations have characterized its mass distribution, fragmentation, turbulence and accretion. We now aim at studying its B-field properties in relation to the existing dense filamentary network that accretes mass at high rates. With ALMA band 6 polarimetric observations, we will study the B-field morphology and determine its role in the stability and fragmentation of the filaments. By determining the B-field strength, we will estimate the energy balance between gravity, magnetic and kinetic energies, and examine whether the outer region of the filamentary network is subcritical, becoming supercritical at the center where most gas and stars accumulate. This will be the first detailed study of the B-field in the well-known region SgrB2(N). | High-mass star formation | ISM and star formation | 2024-03-06T16:58:40.000 |
| 3632 | 2017.1.00814.S | 68 | 9io9: radio-mode feedback under the microscope at the peak epoch of cosmic SMBH accretion and star formation | We propose a detailed study of the gas and dust in an exceptionally bright (~1 Jy) strongly lensed radio-loud AGN, seen at the peak epoch of cosmic star formation and SMBH accretion. Our target is the likely progenitor of a massive galaxy today, seen less than 3 Gyr after the Big Bang, caught during a period of radio-mode feedback. We will study the astrophysics of its ISM, resolving star formation in the host from the AGN, on physical scales of 230-350 pc. We will map CO(4-3) and [CI](1-0) to trace the mass and dynamics of the dense and diffuse molecular reservoirs, using this diagnostic to reveal variations in the gas mass density fraction, which is sensitive to the ISM turbulent velocity structure. We will obtain matched-resolution continuum maps in bands 4, 8 and 9 to construct a resolved map of the thermal dust emission, exploiting this to a) quantify the relative contribution of the AGN and starburst to the bolometric luminosity, b) map the radio-to-IR ratio, and c) map variations in the average dust temperature to investigate the potential role and region of influence of AGN heating. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-08-29T13:58:33.000 |
| 3633 | 2011.0.00777.S | 0 | Imaging the Peculiar Carbon-Chain Chemistry of IRAS 15398-3359 in Lupus - 2 | IRAS15398-3359 in the Lupus molecular cloud is a Class 0 protostar showing peculiar carbon chemistry. In this source, we have found that various carbon-chain molecules and their related molecules such as CCH, c-C3H2, and C4H are extremely abundant. Since these molecules are generally deficient in star forming regions, a similar source is very rare. Only exception known so far is L1527 in Taurus. In these two sources, carbon-chain molecules would be regenerated by evaporation of CH4 from grain mantles followed by subsequent gas-phase reactions(Warm Carbon-Chain Chemistry: WCCC). We have observed carbon-chain molecules in L1527 with PdBI, and have found that their abundances are indeed enhanced in the CH4 evaporation region(20-30 K: 1000-2500 AU) around the protostar. Furthermore, the abundances decreases in the central 300-600 AU region, suggesting that they are partly destroyed and/or depleted in the innermost part. In order to establish the concept of the WCCC, it is indispensable to investigate the distributions of carbon-chain molecules in another WCCC source, IRAS15398-3359, at high resolution. Then, we here propose to observe CCH and other carbon-chain related species toward this source. Similarity and difference between the two WCCC sources provide us with important information on the origin and the mechanism of the WCCC. Now the WCCC is recognized as one of the extreme chemical nature of low-mass protostellar cores. The other extreme case is hot corino, characterized by rich existence of saturated complex organic molecules such as HCOOCH3 and C2H5CN. Since the chemical composition of protostellar cores can be regarded as the initial condition for chemical evolution to protoplanetary disks, a thorough understanding of the WCCC through this observation is of fundamental importance in astrochemistry and related fields. | Astrochemistry, Low-mass star formation | ISM and star formation | 2014-01-16T04:11:00.000 |
| 3634 | 2019.2.00146.S | 112 | Tracing the Flow into Dense Cores in High-Mass Star Forming Filaments | High-mass star forming clouds often exhibit filamentary structures in which dense cores of ~<10 Msun are embedded. In order to form high-mass protostars, these dense cores must accrete gas from the environment. However direct evidence of accretion onto dense cores in filaments is rare. We have selected 8 massive filamentary clouds encompassing a variety of evolutionary phases, and obtained ALMA 12m array, VLA, and SMA data. Dense cores of ~<10 Msun are found in the filaments. Tentative signatures of accretion along (sub-)filaments and along the line of sight are found with ALMA 12m array data (using optically thick HCO+/HCN and optically thin H13CO+/NH2D lines), but missing flux (lack of short-spacing data) remains a major problem for quantitatively interpreting the accretion signatures. Here we propose to obtain the short-spacing data that are critical for solving the missing flux issue. Two critical questions will be quantitatively addressed: whether there is a correlation between accretion rates and core masses, and whether the ~<10 Msun cores will accrete enough mass to produce high-mass protostars. | High-mass star formation | ISM and star formation | 2022-12-06T18:07:44.000 |
| 3635 | 2015.1.00624.S | 22 | Map molecular cloud chemistry and turbulence across a spiral arm of M83 | Both molecular cloud (MC) chemistry and interstellar turbulence are tightly related to the dynamics of spiral arms. Our gas-grain chemical modeling of MC evolution through a spiral arm has already predicted significant chemical differences between upstream/downstream clouds. However, the chemical differences of MCs and distribution of turbulence between spiral arms and upstream/downstream interarm regions are difficult to investigate in the Milky Way due to our location in the Galactic plane. We use ALMA to map CO, SO, H2CO and CH3OH lines around the the eastern arm of the face-on southern spiral galaxy M83 to investigate the environment dependent cloud chemistry and turbulence properties and to test our chemical models. The results shall be also instructive to the study back in Milky Way. | Spiral galaxies, Galaxy chemistry | Local Universe | 2018-06-28T10:20:43.000 |
| 3636 | 2013.1.00034.S | 51 | Evolution of ISM in Star-Forming Galaxies at z = 1 - 5 | We propose to measure the ISM contents of 180 galaxies at z ~ 1.15, 2.2 and 4.8 -- sampling both the normal star-forming galaxy main sequence and the starburst population with IR luminosities elevated up to 20 above the main sequence. The sample is stellar mass selected at 0.3-4x10^11 solar masses. The ISM masses will be determined from ALMA Band 7 & 6 continuum observations which measure the long wavelength, optically thin dust emission -- this technique has major advantages compared to CO line measures: avoidance of the CO conversion factor issues (i.e. dependence on excitation conditions -- temperature, density and metallicity) and much greater speed (approximately 10 times faster to the same mass limit). With these ISM masses for statistically meaningful samples, we can determine the gas mass fractions as a function of redshift and stellar mass and also investigate the elevated star formation activity above the main sequence. Is the enhanced activity due to larger ISM masses or enhanced efficiency for conversion of gas to stars? | Starburst galaxies | Active galaxies | 2016-02-02T13:35:32.000 |
| 3637 | 2015.1.00878.S | 84 | Circumnuclear molecular disks in early-type galaxies as a probe of black hole masses: Expanding the sample | ALMA will make it possible to measure masses of supermassive black holes in early-type galaxies via an entirely new method, by mapping the kinematics of rotating, circumnuclear molecular disks. HST images provide an optimal method for pre-selection of targets, because ~10% of early-type galaxies have circumnuclear dust disks on arcsecond scales which are associated with regular rotational kinematics. We propose to continue our program, begun in Cycle 2, of observing CO(2-1) emission with subarcsecond resolution from early-type galaxies hosting dust disks selected from an extensive search of the HST archives. Our efficient observations will resolve the gravitational sphere of influence of the black holes and reveal rapid rotation from molecular gas in the inner disks, and we will carry out dynamical modeling to derive constraints on the black hole masses. Once we have determined the CO fluxes and linewidths, in future ALMA cycles we will propose to carry out deeper and higher-resolution observations that will provide exquisitely accurate black hole masses. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-12-06T19:36:00.000 |
| 3638 | 2018.1.00272.S | 115 | Adjusting the Reception of The Antennae: A Clear Look at GMCs in a Major Merger | We propose to map the nearest major merger, the Antennae, in CO (1-0) and (2-1) at giant molecular clouds scales (~40 pc). This iconic system was targeted during ALMA commissioning, but does not yet have a high fidelity, high resolution map of the entire system in a CO line. With active star formation spread out across a range of environments, the Antennae is an excellent proxy for star-forming galaxies and galaxy mergers at moderate redshifts (z=1-2). Using the proposed observations, we will build a catalogue of GMCs with measured properties (radius, linewidth, luminosity), determine the factors driving the formation of super-giant molecular clouds, study the CO(2-1)/(1-0) line ratio and its variations from cloud to galaxy scales, and measure the CO-to-H2 conversion factor for both CO(1-0) and CO(2-1) lines. These observations provide the first high fidelity maps of the molecular gas in the Antenna from the cloud scale up to the full extent of the interacting galaxy disks. | Merging and interacting galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2020-03-08T06:14:40.000 |
| 3639 | 2019.1.01742.S | 290 | AGN Before and After: Towards a balanced view of the link between circumnuclear gas and nuclear black hole activity | We are currently undertaking a comprehensive study of the circumnuclear regions (CNRs) of the most luminous local (D<40 Mpc) southern AGN, selected from the SWIFT/BAT survey. Our AO-assisted VLT/SINFONI, deep XShooter IFU spectroscopy, and HST imaging provide a wealth of information about the inner 3" of these AGN. A crucial element of our large program is the observations of a carefully matched control sample on the same spatial scales, to distinguish between long-lived dynamical processes vs. rapid ones synchronised with the bright AGN event. Large beam single-dish observations in CO(2-1) do not find any substantial difference between our AGN and inactive galaxies. This suggests that the direct link between cold gas and nuclear inflow must be found on the scales of the CNR. Here we propose to observe the remaining 21 galaxies in our sample lacking adequate archival data in Band 6 to map CO(2-1) with 0.4" resolution over 5" scales, complementing the multi-phase tracers from our SINFONI and HST data. This will allow an unprecedented comparative study of the inflow of cold gas in the circumnuclear environment, as well as reveal the link between cold gas and feedback from the AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2021-01-11T21:33:59.000 |
| 3640 | 2023.1.01290.S | 0 | CLASSY&CO: revealing the molecular gas fueling metal-poor star-forming high-z analogs in the local universe | Statistically-significant galaxy samples of the distant universe and reionization epoch have started to be revealed in the current JWST era. The knowledge on their molecular content is crucial to understand the star formation history of the universe. However, this is still unknown in the extremely metal-poor high-z environments. Here we propose to detect and map the molecular gas with the CO(1-0) in a selected subsample of metal-poor and low-mass local galaxies from the COS Legacy Archive Spectroscopic SurveY (CLASSY). CLASSY represents the first high-resolution spectral far-UV catalog of local star-forming galaxies, including high-z analogs, and also collecting multi-wavelength data, from the IR to the UV. CLASSY-CO will allow us to directly explore the connection between the molecular gas reservoir of these systems and the incident far-UV radiation as well as its connection with their interstellar medium properties. Our aim is to shed light on the role of CO as molecular gas diagnostic in high-z environments. Our study will allow to build an extremely powerful toolkit that will be pivotal for understanding the cold gas conditions of the earliest galaxies. | Spiral galaxies | Local Universe | 2025-11-15T18:25:12.000 |
| 3641 | 2022.1.01255.S | 5 | The early evolution of super star clusters in the nuclear starburst of NGC 4945 | We propose to use the unparalleled capabilities of ALMA to perform Band 7 imaging and spectroscopy of NGC4945, the nearest archetypal example of a starburst and AGN (Sy 2) nucleus. ALMA Band 3 imaging and recombination line observations have revealed the presence of super star clusters (SSCs) in the central starburst, which are highly obscured at NIR wavelengths. However, the Band 3 observations lack the sensitivity to identify the full cluster population and lack molecular spectroscopy probing the very-dense, cluster environment. Band 7 spectroscopy at 1.8 pc resolution of CS 7-6 and H13CN 4-3 from highly-excited dense gas will allow us to determine the kinematics, virial mass, and radial momentum associated with each cluster. We will also obtain Band 7 continuum imaging to trace the dust, a mass-dominant component of SSCs, and its spectral index, an indicator of the dust opacity and therefore feedback from dust-processed radiation pressure. The proposed observations enable the next steps in our understanding of the formation and evolution of young, massive clusters. | Starbursts, star formation | Active galaxies | 2024-07-20T15:23:41.000 |
| 3642 | 2024.1.00406.S | 0 | The Rise of Ziggy Stardust: Dust Build-up in the Epoch of Reionization | In recent years, ALMA has revealed the presence of massive dust reservoirs well into the epoch of reionization. However, it remains unclear how these dust reservoirs were assembled on such short timescales. Two competing theories exist: either dust is efficiently produced by early supernovae, or dust reservoirs rapidly grow through grain growth in the ISM. The only way to reveal which of these processes is dominant at high-z, is through a combined analysis of dust and metals. We propose for ALMA Band 8 observations of a complete sample of 8 massive galaxies at z~7 with metallicity measurements from JWST/NIRSpec IFU observations. Our targets were all previously detected in [CII]158 and underlying continuum emission, but their current single-band dust mass estimates remain uncertain by 1 dex, preventing any insight into their dust production pathways. By measuring accurate dust masses from dual-band observations, we will reveal whether grain growth dominates high-z dust production in massive galaxies, or whether distant supernovae are highly efficient dust producers. These observations will shed light on the fundamental question of how the earliest dust reservoirs are assembled. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 3643 | 2022.1.01713.S | 20 | Probing the Excitation and the Mass-Luminosity Conversion Factor of the Dense, Star Forming Gas Across Galaxy Disks | We propose ACA Band 6 observations to map the J=3-2 line emission of the canonical, extragalactic dense gas tracers HCN and HCO+ in 8 nearby disk galaxies. The target fields cover a broad range of environmental conditions. Our main goal is to constrain the excitation and, more generally, the physical conditions of the dense, star forming gas across disks. In external galaxies, such studies were largely focused on bright galaxy centers or (U)LIRGs at low, kpc-scale spatial resolutions or in very compact nuclear regions. This proposal will multiply the number of galaxies and range of environments at sub-kpc scales. Our ultimately goal is to link: (1) the excitation conditions of the dense, star forming gas; (2) the cloud properties derived from physically-motivated radiative tranfer modelling; (3) and the environment the clouds live in. Further, line ratios are essential to constrain the HCN conversion factor from which dense gas masses are derived. We will revisit the scaling relations between dense gas and star formation that help us differentiate between competing models for how star formation is regulated across galaxies. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2025-06-13T16:16:47.000 |
| 3644 | 2023.1.00430.S | 0 | Detecting Dust in a Sample of Lensed Quiescent Galaxies at Cosmic Noon | Using ground- and space-based imaging and rest-frame optical spectroscopy, we have identified a remarkable sample of 12 strongly-lensed massive red quiescent galaxies at z=0.7 to z=2.5 (to be combined with 6 archival targets). Using ALMA Band 6 continuum imaging, we propose to measure their total dust masses down to unprecedented dust fraction levels of 0.01%. Tension exists in the literature regarding the ISM in quiescent galaxies: stacked dust continuum (15 arcsec resolution) of statistical samples at high redshift yield moderate dust masses, whereas recent model predictions suggest dust masses should be orders of magnitude lower. Gravitationally lensed quiescent galaxies offer a unique opportunity to resolve this conflict by pushing into uncharted parameter space, and have started to point towards consensus with theoretical predictions. In this proposal, we aim to triple the number of individually observed galaxies. Such strong limits on dust mass are only possible due to the combination of strong-lensing magnification and ALMAs exquisite sensitivity. Now we have sufficent samples to distinguish between stacks and theory at >5 sigma confidence for samples at z~1 and z~2. | Early-type galaxies | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 3645 | 2017.1.00693.S | 83 | Tracing the water content of protostars in isolated cores | One of the key questions concerning the origin of our Solar System is how water has evolved on its way from collapsing molecular cloud cores, to protoplanetary disks and eventually Earth's oceans. Observations of the amount of deuterated relative to non-deuterated water (HDO/H2O) has been used to argue that a similarity exists between the water found in comets and that formed in ices in the envelopes and disks around young stars. Recent models show that the main isotopologue, H2O, is predominantly formed at low densities in the early prestellar phases and the deuterated isotopologues only later. If that is the case, protostars in isolated cores should show significantly different water D/H ratios than those in the relatively dense regions that have been observed so-far. In this proposal, we will test this suggestion by measuring the HDO/H2O ratio for three isolated cores, utilising, in particular, the H2-18-O 203 GHz transition that has been made accessible with the commisioning of the new Band 5 receivers. If it indeed turns out that the water D/H ratio is different for these cores, it may provide a new way of assessing the early evolutionary history of young stars in general. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-03-27T13:20:17.000 |
| 3646 | 2013.1.01102.S | 42 | Highlighting the Centrifugal Barrier in Protostellar Envelopes by Chemistry | In star formation studies, one of the most important issues is when and how the rotationally supported disk is formed around a protostar. In this proposal, we approach this problem by chemistry. With our ALMA Cycle 0 observations toward the low-mass Class 0 protostar L1527, we discovered a drastic chemical change in the transition zone between the infalling rotating envelope and the inner disk. Carbon-chain molecules as well as CS mainly exist in the infalling rotating envelope, whereas SO selectively trace the transition zone. This drastic change seems to originate from the accretion shock in front of the centrifugal barrier. Thus, chemistry can highlights the transition zone. Moreover, the protostellar mass and the specific angular momentum can easily be derived by the radius of the centrifugal barrier and the rotation velocity there. Based on this success in L1527, we apply this method to 5 low-mass protostellar sources in the Class 0 and I stages with different chemical and physical characteristics to verify the applicability of this method. This observation will open a new avenue to study the physical and chemical evolution associated with disk formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2016-07-14T00:00:00.000 |
| 3647 | 2022.1.01300.S | 52 | SPT0303-59: The most extreme proto cluster candidate from the SPT sample | In the local universe about half of all galaxies live in clusters and galaxy over-densities. But in the past decade most observational efforts to investigate galaxy evolution have focused on the evolution of field galaxies through cosmic time. Studies of the evolution of clustered environments have been proven to be much more challenging due to difficulties to find high redshift proto cluster (PC) candidates in significant numbers. With the advent of mm/submm surveys covering hundreds of sq. degrees with Herschel and the South Pole Telescope the situation has improved significantly and the number of published PC candidates at high redshift is finally ramping up. In this proposal we focus on a a spectacular over-density of DSFGs discovered by LABOCA@APEX in a field initially selected from the South Pole Telescope survey. If confirmed as a coherent structure, it would be the most actively star forming PC discovered in the entire SPT survey. So far only a photometric redshift is available for this source, which we aim to change with this proposal. | Starburst galaxies | Active galaxies | 2024-02-01T22:39:05.000 |
| 3648 | 2018.1.01598.S | 6 | Taking snapshots of the jet-ISM interplay | We propose to search for and characterise the molecular outflow in two of the closest powerful and young radio galaxies: PKS1934-63 and PKS0023-26. We plan to do this by observing CO(2-1) at 0.2" resolution. The proposed objects are going through the very interesting phase of a newly born radio jet expanding in the surrounding medium. In this phase the plasma jet can have the largest impact on the ISM and state-of-the art simulations are now able to make predictions about this impact. The requested data will allow a detailed comparison with these predictions. The targets expand to high power the successful work done so far by our group aimed at characterising the role of radio jets in driving molecular outflow and carry out comparisons with simulations. Albeit of comparable radio power, the two sources are in different stages of their evolution, allowing us to get snapshots of the effect of the radio jet as it expands through the ISM. The proposed targets show ample evidence of outflows from optical and nearIR but the ALMA observations will shed light on the most massive component of the outflows, the cold molecular gas, and fully quantify the impact on the host galaxy. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-01-09T18:21:29.000 |
| 3649 | 2023.1.01058.S | 0 | Quantifying the vertical concentration of intermediate dust grains using edge-on protoplanetary disks | Dust settling, which occurs when drag forces overcome the vertical stirring induced by turbulence and instabilities, allows to concentrate dust particles in the disk midplane and favors planet formation. However, its efficiency remains unknown, especially for dust particles of intermediate sizes between micron and millimeter sizes, previously characterized by scattered light and millimeter observations. We propose to extend the studies of the disk dust vertical extent to the submillimeter, to reduce the wavelength gap between existing observations. We aim to resolve the vertical extent of 6 well-studied highly inclined disks in band 9 (0.45mm), for which HST, JWST, and vertically resolved ALMA 0.9mm or 1.3mm observations already exist. We will use radiative transfer models to estimate the corresponding scale height of such particles and compare it with constraints already available at other wavelengths. This will allow us to quantify for the first time any variation of vertical extent with grain size, and will provide critical information on the turbulent structure of disks and the level of vertical concentration, which are essential parameters to understand planet formation. | Disks around low-mass stars | Disks and planet formation | 2025-10-09T15:06:24.000 |
| 3650 | 2022.1.01515.S | 641 | An unbiased census of the molecular gas content in the most massive galaxies in the nearby Universe | The rapid decline in baryon content towards the upper end of the galaxy mass function is one of the major open questions of galaxy evolution. It has been attributed to phenomena as diverse as environment, stellar mass-surface densities, bulge potential, and AGN feedback. We will use the ACA for a CO(1-0) survey of a purely mass-selected sample of 197 galaxies at z<0.3 with M_stellar 10^11-12 Msun, where the baryon deficit in galaxies is strongest. Our survey extends the xCOLD-GASS survey, which has been very successful in characterizing the cold gas in galaxies with stellar masses 10^9-10 Msun, but includes few galaxies above >10^11 Msun. Our sources fall within the SDSS Stripe 82, and have all SDSS spectroscopy, LOFAR and VLA radio imaging, and a rich sets of other photometric constraints. We will measure the local H2 mass function out to the highest masses, and obtain, e.g., integrated molecular gas masses, mass fractions, and gas consumption times as a function of the stellar, radio, and AGN properties of our sources, placing unbiased constraints on each of these characterstics in regulating the gas content and star formation efficiency in the most massive galaxies today. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2024-08-17T15:55:35.000 |
| 3651 | 2023.1.00466.S | 0 | Moving Past Small Number Statistics in Astrochemistry: A Molecular Survey of Two Dozen Hot Cores | Studies of chemical evolution have traditionally focused on a small number of exceptionally molecularly rich and bright sources due to the historical difficulty in detecting complex interstellar molecules. This small sample size biases our understanding of 'standard' chemical evolution, and prevents calibration of chemical models to standard conditions. Single-dish surveys that have attempted to address this issue by surveying substantially larger sample sizes have suffered from extreme beam dilution, due to the very small angular size of typical chemically rich hot cores. Here, we propose to exploit both the sensitivity and spatial resolution of ALMA to finish conducting a distance-limited survey of two dozen hot core sources. We target several spectral windows designed to provide the maximal scientific return, and will use the results to calibrate several of the industry-standard models and identify critical areas in which these models need refinement. | Astrochemistry | ISM and star formation | 2025-06-12T00:38:20.000 |
| 3652 | 2019.1.01025.S | 130 | A Comprehensive Study of Quasar Host Galaxy and Cosmic Reionization with a Large Statistical Quasar Sample at z>6.5 | The detection of intergalactic medium (IGM) damping wing absorption profiles in the spectra of two z>7 quasar suggests that we are witnessing the epoch of reionization (EoR). Recently, our group have tripled the number of known quasars at z>6.5, establishing the first statistical sample of EoR quasars. The quasar luminosity function measured from this sample indicates the decline of quasar number density accelerated at z>6.5, strongly suggesting a new phase of quasar evolution close to the epoch of the earliest supermassive black hole (SMBH) formation. Here, we propose to observe thirteen newly discovered z>6.5 quasars (the majority of which are unpublished) to detect the [CII] and continuum emission in their host galaxies. The ALMA observations will measure star formation rate and constrain dynamical mass, enabling the first statistical study of the coevolution of SMBHs and host galaxies during the EoR. We will identify [CII] companions and search for the signatures of galaxy merger and AGN feedback. Furthermore, the precise [CII] redshift measurements will be crucial in modeling IGM absorption and in identifying young quasars in the early Universe. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2021-01-11T21:43:24.000 |
| 3653 | 2012.1.00603.S | 31 | Tracing evolution of giant molecular clouds in the Large Magellanic Cloud | The Large Magellanic Cloud (LMC) is the nearest neighbor to our own galaxy, and its nearly face-on view allows us to unambiguously identify young objects associated with GMCs over a galaxy. We classified the GMCs into three types according to the activities of massive star formation, corresponding the evolutional sequence of the GMCs. One of the features of the GMCs in the LMC is that there are a large number of starless GMCs, suggesting that the timescale in star formation is significantly longer in the LMC than in the Galaxy. This may be due to the higher ionization degree and smaller cooling rate as a consequence of lower metallicity in the LMC, and it is tempting to speculate that there is a link between populous clusters and the starless GMCs. This proposal then aims to investigate the physical properties of the GMCs probing dynamics of the clouds by utilizing the detailed study of mass spectrum, line width-Size relation, virialization of clumps and star formation activities, characteristics of precluster forming cores, and so on by using a sample of resolved clumps. These relations and characteristic can be compared with theories and should include important information of the dynamics of the molecular contents. We then propose to conduct high spatial resolution observations of GMCs with different evolutionary stages in the lines of 13CO(1-0), C18O(1-0), CS(7-6), and H40alpha to be compared with the other data exhibiting star formation activities. This type of observations can be achieved for the first time during the Cycle 1, and then our knowledge of the GMCs will be greatly improved. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2016-11-24T00:00:00.000 |
| 3654 | 2016.1.00366.S | 36 | Direct Imaging of Gas Gaps in the HL Tau Disk | The ALMA long baseline campaign discovered a series of ring-like gaps in the (sub-)millimeter continuum emission in the HL Tau disk, making HL Tau possibly the youngest candidate of ongoing planet formation. To understand the origins of the gaps in the HL Tau disk, planet formation or other mechanism solely incorporating dust properties, the knowledge of depths and widths of the gas gaps and dust-gas coupling (depending on dust-to-gas mass ratio) is essential. We have analyzed the HCO+ (1-0) data obtained with the same ALMA observations, and identified two gas gaps coincident with the dust gaps in the disk. However, with only one transition HCO+ (1-0), our derived gas temperature and density, and thus widths and depths of the gas gaps remain uncertain because of the not well constrained HCO+ excitation condition and gas temperature. Therefore, We propose to observe the HL Tau disk in HCO+ (3-2) and (4-3) at angular resolutions of ~0.07". With the proposed observations, we will have three transitions to constrain gas density and temperature and HCO+ abundance, and provide more precise measurements of widths and depths of gas gaps and gas-to-dust mass ratio to distinguish models. | Disks around low-mass stars | Disks and planet formation | 2018-11-02T18:52:44.000 |
| 3655 | 2021.1.00713.S | 130 | The impact of magnetic field in the core fragmentation and the formation of single and binary stars | The role of magnetic field in the fragmentation from ~0.01 pc scale condensation to single, binary, or high-order multiple systems has not been explored yet following a statistical approach, because the lack of the magnetic field observations of a large sample at ~0.01 pc scales. Recently, ALMA have made significant progress in studying the magnetic field at ~0.01s pc scales toward massive star cluster-forming regions. We build this ALMA proposal on these great progresses with the aims of addressing: how does magnetic field affect the fragmentation and the formation of single/binary/multiple systems in the massive star cluster-forming regions? what are the properties of final fragments, e.g, multiplicity fraction and the distribution of companions separation? Our case study of G333 has revealed some hints on these subjects. However, statistics studies are needed to reach a comprehensive understanding of multiple systems formation. | High-mass star formation | ISM and star formation | 2023-08-04T19:54:54.000 |
| 3656 | 2016.1.00139.S | 343 | The most intrisically luminous starbursts in the Universe: witnessing the birth of the red sequence | Using all the ALMA-accessible SPIRE imaging, we have defined a sample that is both faint (ergo mostly unlensed) and extremely red (ergo very distant). We further refined this sample via SCUBA-2/LABOCA imaging, choosing only those where z_phot>4. We then demonstrated the remarkable accuracy of our refined z_phot estimates via spectral scans, and discriminated cleanly between lensed galaxies (typically <1" Einstein rings, interesting in themselves) and intrisically luminous starbursts via our very efficient high-res band-7 continuum snapshots, discovering extraordinary examples of both. Our goals here are: 1) to identify and more than double the number of the most intrisically luminous starbursts in the z>4 Universe, galaxies that are missed by SCUBA-2 surveys due to area and by SPT due to sensitivity. We thereby pinpoint the most massive dark matter halos at these early epochs, in which we find the precursors of galaxies on the red sequence; 2) to directly characterise the physical scale and morphology of their dusty star-forming gas; 3) to robustly challenge popular models of galaxy formation via their morphologies and by determining a considerably more accurate source density. | Starburst galaxies | Active galaxies | 2018-12-18T12:03:24.000 |
| 3657 | 2015.1.00217.S | 68 | The molecular cloud structure in the low-metallicity environment of 30 Doradus | Our understanding of how gas is converted into stars quickly deteriorates as the metallicity of the interstellar medium decreases. While molecular gas is commonly accepted to be the main star-forming reservoir in normal galaxies like our Milky Way, the difficulty in tracing molecules in metal-poor galaxies complicates our ability to evaluate the star-formation efficiency or even the mere importance of molecular gas in the star-formation process. We propose a detailed modeling of the photodissociation front and molecular cloud in the half-solar metallicity environment of 30Dor in the Large Magellanic Cloud, in order to quantify the total molecular gas mass and the fraction of this gas that is not traced by the usual tracer CO (the CO-dark gas). Thanks to our previous modeling effort using Herschel tracers at 10pc resolution, we have identified a optimized combination of ALMA tracers that will provide the sufficient constraints to achieve our goals at 0.1pc resolution, i.e., a scale small enough to examine the transition between physical layers in molecular clouds. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2019-03-07T00:00:00.000 |
| 3658 | 2011.0.00124.S | 0 | Spatially extended [CII] in a z=4.8 SMG | We propose spatially resolved [CII] and continuum observations of the z=4.8 submillimetre galaxy LESS J033229.4-275619. This source is one of the highest redshift SMGs currently known, and its far-IR SED is not dominated by AGN emission. The [CII] emission is enhanced relative to CO, which is likely due to the lower metallicity. This may also imply that CO is missing a substantial fraction of the molecular gas, which could still be traced by [CII]. The 0.5" spatial resolution offered by the extended configuration will resolve both the [CII] and FIR emission, providing a first glimpse (in just 1 hour of total observing time!) of this ratio which is sensitive to the physical origin of the emission. This resolution is also ideally matched to our rich multi-wavelength data, and especially the HST/WFC3 near-IR imaging (as part of CANDELS) of the host galaxy stellar emission. The combined analysis will provide a direct determination of the spatial extent of the star forming regions within this forming galaxy. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2013-10-12T11:15:00.000 |
| 3659 | 2015.1.00543.S | 10 | Towards a census of star-formation since z~6 with ALMA-1.1mm | We propose to carry out a wide (10'x6.8') and deep (128 microJy rms) ALMA 1.1mm survey in GOODS-South requiring 21.9 hrs of observing time. The combined power of ALMA and Herschel will probe the dust (hence also gas) content and SFR (hence SFE=SFR/Mgas) of galaxies out to z=3.5. It will also open a new window on previously undiscovered dusty star formation out to z~6-8, an era previously studied only with UV emission and untested extinction corrections. With ALMA's exquisite angular resolution and sensitivity, >4-10 times deeper than existing sub-mm surveys, these data will provide the missing link between the obscured and unobscured Universe, allowing the deconfusion of Herschel data and permitting statistical studies of galaxy populations via detections and stacking. Our team brings together astronomers with extensive experience with the GOODS-S multi-wavelength dataset, especially Herschel, JVLA, HST and Chandra. In comparison to the previous Cycle 1 ALMA 1.3mm survey in the HUDF, we will cover a 17x wider area, detect 5-7 times more sources, and reach a complete census on the cosmic SFR density of M*>3-4x10^10 Msun galaxies over z=0-6 with ~0.15 dex uncertainty. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-09-22T19:55:18.000 |
| 3660 | 2018.1.00523.S | 370 | The spectacular BHR71 protostellar outflow system | Protostellar jets and bipolar outflows play a critical role in the star-formation process. They remove angular momentum from the protostar+disk system, while injecting momentum and energy into the surrounding core, affecting the core chemistry and limiting the effciency of protostar formation. We propose to map the entire BHR71 protostellar outflows with ALMA with 0.6" resolution (120 au) in CO (2-1) and its isotopologues, SiO (5-4), and select outflow tracers to address the following questions: 1. How does the outflow jet/wind entrain molecular material and how effcient is this process? 2. Are outflows energetic enough to disperse the dense core and hence terminate protostellar accretion? 3. Are outflow cavities due to wide-angle flows, or precessing jets? 4. What constraints do outflow morphology place on the protostellar accretion process? | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2020-07-08T18:56:29.000 |
| 3661 | 2017.1.01672.S | 4 | Quantifying Penumbral Jet/Microjet Dynamics in the Low Solar Atmosphere | We propose to investigate penumbral jets and microjets, which are small-scale energy release events that occur in the solar chromosphere near sunspots. Such events are implicated in heating the solar atmosphere, and the basic processes are thought to be similar to larger jets and solar flares powered by magnetic reconnection. However, the exact nature of the energy release processes remains poorly understood. Recent progress in high resolution optical and infrared imaging observations have greatly advanced our knowledge on these events. However, interpretation of such observations is often complicated by the complex ionization and radiative transfer processes responsible for the observed line and/or continuum intensity. ALMA mm observations, regarded as a linear thermometer thanks to the Rayleigh-Jeans Law, provide an excellent means of constraining the detailed dynamic thermal structure in the energy release site with unprecedented spatial and temporal resolution. The largely predictable locations and frequent occurrence of such jets make them a practical choice regarding the restricted field of view of ALMA and the declining solar activity level. | The Sun | Sun | 2019-10-02T13:15:35.000 |
| 3662 | 2016.1.01037.S | 31 | After the Storm: Mapping the Highly Disturbed Molecular Gas in the Taffy Galaxies and Bridge | We propose to map CO emission in the galaxies and molecular bridge of the Taffy system (UGC 12914/5). We will use the observations to explore the physical conditions of the gas in the highly turbulent bridge created by the dramatic head-on collision of the two gas rich galaxies, which unlike most major mergers is not forming stars at a high rate. We will attempt to explore the structure of the clumpy molecular clouds in a diverse range of conditions in the turbulent gas. We will investigate the kinematics of the gas down to small scales to measure how kinetic energy is dissipated across the bridge. We will also use the CO SLED to probe the density and temperature of two peculiar regions to separate spatially the cool diffuse, and warm dense gas. We will determine how turbulence and shocks dissipate energy, and how this correlates with star formation. The study of this nearby turbulent system in great detail may help us understand how turbulence can inhibit star formation at modest redshifts when galaxies were more gas-rich, and when the star formation rate density began to rapidly decline. | Merging and interacting galaxies | Galaxy evolution | 2019-04-06T00:00:00.000 |
| 3663 | 2011.0.00619.S | 0 | Identification of the Keplerian-Rotating Disk around the Protobinary System of L1551 NE | We propose to make an ALMA cycle 0 observation of L1551 NE in the C18O (3-2), 13CO (3-2), CS (7-6), and the HC18O+ (4-3) lines at Band 7 with the extended configuration. L1551 NE is one of the archetypal Class I binary protostellar systems with two radio continuum sources at a projected separation of ~70 AU (Source A at the south-east and Source B at the north-west). Our recent SMA observations of L1551 NE in the C18O (3-2) line have found a 500-AU scale elongated feature along north-west to south-east, approximately centered on Source A. The circumbinary feature shows a clear velocity gradient along the major axis, and our simple model fitting to the observed C18O image cube suggests a possibilty that the circumbinary feature is a Keplerian rotating disk centered on Source A with the central mass of 0.8 M, inclination angle of -62 deg, and the position angle of 167 deg. The rotation power-law index is, however, not well-constrained with the SMA data, and it is still possible that the rotation is non-Keplerian. The higher-resolution, higher-sensitivity ALMA observation will be able to unambigously assess the presence (or absence) of the Keplerian motion in the circumbinary disk. Once we confirm the presence of the Keplerian-rotating circimbinary disk, we can directly measure both the mass of the protobinary system and the mass ratio, which can put stringent constraints on the theories of binary star formation. We believe that the present first ALMA observation to identify the Keplerian circumbinary disk around one of the prototypical binary protostars is a solid kick-off to approach binary formation with ALMA. | Low-mass star formation, Disks around low-mass stars | ISM and star formation | 2014-02-27T05:19:00.000 |
| 3664 | 2017.1.01627.S | 23 | Towards an evolutonary sequence in young planetary mass companions | In recent years a small number of planetary mass companion candidates (PMCs) at large orbital distances from their host stars have been identified. Their formation mechanism remains unknown, but studying the PMCs that are still in formation is providing some vital clues. We have selected 5 young PMC candidates aiming for a detection of their circumplanetary disks through ALMA 1.3 mm observations. The proposed observations will be deep enough to provide strong constraints on the potential circumplanetary disk structure, the reservoir of proto-lunar material and its relation with the circumstellar emission. Our targets span a wide range of young ages, so the proposed observations could represent the starting point for establishing an evolutionary sequence for PMC formation. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2019-10-30T00:59:38.000 |
| 3665 | 2021.1.00614.S | 9 | ALMA & MUSE synergy to explore the impact of AGN-feedback on the circumgalactic gas | Recent MUSE observations of a Broad Absorption Line (BAL) QSO at z~5, revealed a Lyman-alpha (Lya) nebula with high broadening of the line (FWHM~1500 km/s) in the inner region (~20 kpc) of the circumgalactic medium (CGM), almost doubling average values commonly observed around typical QSOs. This is likely to be associated to the BAL-nature of the object, which shows CIV absorption troughs blueshifted by more than 30.000 km/s, indicating high velocity outflows, that could inject energy and introduce significant turbulence on 10-kpc scales. These findings suggest a profound link between QSOs and the properties of their surrounding CGM. Here we propose deep Band-7 ALMA observations targeting the [CII] line over scales of ~60 kpc around the QSO. We aim to (i) observe the spatially extended outflow and the metal-rich quiescent gas reservoir in the CGM, and (ii) explore their connection with the observed properties of the Lya nebula. We will probe how powerful outflows can influence the morphology and the kinematics of the gas in the CGM on scales of (at least) tens of kpc around the QSO, adding novel, key information on the impact of AGN-feedback on the environment of AGN-host galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2023-04-11T20:14:24.000 |
| 3666 | 2016.1.00632.S | 13 | Mapping Dust in an Occulting Dwarf Galaxy | The role of dust in shaping the spectral energy distributions of low mass galaxies remains poorly understood. Recent results from the Herschel Space Observatory imply that dwarf galaxies contain large amounts of cool (T~20K) dust, coupled with very modest optical extinctions. These seemingly contradictory conclusions may be resolved if dwarfs harbor a different dust geometries and compositions. We propose ALMA observations of an occulting dwarf galaxy already observed with the Hubble. HST has mapped the dust in attenuation and ALMA Band-7 observations will map dust emission in equally exquisite detail. The ratio of dust thermal emission and attenuation will constrain future SED models of smaller disk galaxies, map the role of turbulence in small disks, and map the full disk of both galaxies, probing their respective symmetry. ALMA observations will break the dichonomy seen in stacked SEDs; is the disk simply more extended, or very clumpy and cold? What kind of structures dominate throughout and what is the typical relation between starlight attenuation and dust sub-mm emission? How big is the role of turbulence in the dusty ISM seen in the spatial power spectrum? | Dwarf/metal-poor galaxies | Local Universe | 2018-07-20T20:52:49.000 |
| 3667 | 2019.1.01172.S | 46 | Mapping mass outflows in an EXor Ourburst | We have discovered a molecular outflow around the prototype EXor outburst source EX Lup. ALMA 12m array data at 0.3" resolution detect the edges of a wind-swept cavity and ambient-velocity gas from an envelope. The environment of EX Lup is more complex than previously realized, and shows features in common with the related, higher-amplitude, FUor type of eruptive young stellar objects. Those observations were limited to structure on scales < 3.2" (500 au), and thus limit attempts to explore the intermediate/large-scale gas structures discovered around EX Lup. We propose to use the 12m+ACA+TP arrays to map the environment around EX Lup on 0.3"-45" scales (50-7000 au) in order to measure the structure, mass, and kinematics of the outflow and the remnant diffuse gas. This will allow us to correlate outflow and accretion processes in a system having a recent outburst (~10 years ago), shed light on the relationship between FUors and EXors, and will be a pathfinder for investigations in other EXors. Ultimately, this will lead to a better understanding of the interplay of late-stage accretion and outflow processes in driving the evolution of planet-forming disks in low mass stars. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2021-03-11T13:23:12.000 |
| 3668 | 2023.A.00041.S | 0 | Supplemental Pre-Burst Observations of the recurring Nova T CrB | We already have an accepted DDT proposal (2023.A.00038.T) on T CrB, the closest known recurrent nova, with recurrence period of 80 years, which is expected to have its next outburst before the end of 2024. But based on first observations obtained from that proposal in August 2024, we find that the object is presently (pre-burst) much fainter than could be expected from the only spectrally adjacent VLA observations (from 2016), such that we have only achieved 5 sigma detections in bands 3, 4, and 6, and marginal to non-detections in bands 1 and 7. Furthermore, an unknown potential source at 7 arcsec offset is detected at 5 sigma in band 1. We therefore request supplemental observations in ALMA B1 and B7 to augment our existing data and obtain proper detections in all bands, and rule out or confirm the spurious detection at 7 arcsec offset in Band 1. | White dwarfs, Transients | Stars and stellar evolution | 2025-04-11T15:29:27.000 |
| 3669 | 2019.1.01051.S | 6 | Snow Lines and the Seven Rings: Resolving Polarized Substructures in HL Tau | The Band 7 polarization morphologies of disks indicate that the polarized emission is from scattering. However, the scattering model is significantly affected by the underlying structure, grain composition, and optical depth, which varies significantly for scales less than 10 au. Hence it is necessary to resolve the polarization at small scales. We propose for 4.5 au polarimetric observations of HL Tau, the only disk where such high resolution polarimetric observations are possible, to both test the scattering model and infer properties of the disk. These observations will map polarization for both gaps and rings, which will allow us to discern which gaps are the most conducive for forming planetesimals/planets. Moreover, we will test how grain composition, snow lines, and optical depth affect the polarization morphologies. This polarimetric legacy datsaset of HL Tau is likely the highest resolution that will ever be created by the current rendition of ALMA, and thus will be the most modeled dataset for dust scattering. | Disks around low-mass stars | Disks and planet formation | 2023-07-26T13:06:16.000 |
| 3670 | 2023.1.00653.S | 0 | Metallicity and dust content in J0100+2802, the most massive quasar in the reionization epoch | Having by far the largest black hole mass at high redshift, J0100+2802 at z=6.3 is the best laboratory to study if quasars truly represent the site of the earliest structure formation and chemical evolution. However, recent ALMA observations show that J0100+2802 has a dust mass surprisingly as low as a few times 1e+7 Msun, similar to those in normal star-forming galaxies without AGN at a similar epoch. This poses a severe question whether the target is chemically enriched system. Here we propose to observe four emission lines ([OIII]88, [NII]122/205, [OI]145) and Band 9 dust continuum of the target to securely measure the gas-phase metallicity and dust mass. We will test if J0100+2802 truly represents a chemically enriched system or an object with a relatively low metal and dust content. If the former is confirmed, it will evidence that the host galaxy of J0100+2802 is chemically enriched at z ~ 6, and if the latter, this will pose a severe question to the current understanding of the galaxy-BH coevolution. This is a resubmission of a Cycle 9 program, and we removed the Band 8 [OIII]88 and Band 9 dust continuum observations that are already performed from the current proposal. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-08-21T01:15:45.000 |
| 3671 | 2023.1.00140.S | 9 | Molecular gas content of novel isolated star forming clumps | We request 9.9h of 12m array and 59.4h of 7m array time to perform the first ever CO observations of a recently identified class of peculiar blue stellar systems, known as "blue blobs." To date only five blue blobs are known, all in the Virgo galaxy cluster. These young and metal-rich systems contain very few stars (M* < 10^5 Msol) and are remarkably isolated, like tiny blue oases in the enormous red desert of the cluster. They likely formed from stripped gas, but must have traversed up to 100s of kpc through the hot intra-cluster medium while retaining enough molecular gas to form stars, and are likely the first examples of star formation in isolated cloudlets supported by external pressure. Existing observations of all five targets with HST, MUSE/VLT, and the VLA have revealed their unusual stellar populations, metallicities, and atomic gas content. ALMA CO(2-1) observations will complete the picture by providing spatially and kinematically resolved maps of molecular gas, allowing us to address key questions about the nature and fate of these novel objects, which in turn will have implications for our understanding of ram pressure stripping in galaxy clusters. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-12-05T13:43:32.000 |
| 3672 | 2018.1.00939.S | 19 | A search for water maser emission in Compact Obscured Nuclei | In recent years, observations of vibrationally excited HCN emission have revealed the presence of extremely compact, dense and obscured nuclear environments in the centers of local (U)LIRGs. These regions, called Compact Obscured Nuclei (CONs), can be as compact as ~20pc, with column densities that can reach values greater than 10^(25) cm^(-2), and have temperatures of >1000K. The most likely nature of the object in the center of these CONs is a dust-enshrouded highly-accreting AGN, and/or an optically thick and compact (<100pc) starburst region. CONs likely represent an important phase of intense growth in the nucleus of galaxies, and fully understanding the mechanisms taking place in their midsts could prove an important step in improving our theories of galaxy evolution. We propose for 183GHz water maser observations of a sample of known CONs observable by ALMA in order to trace the innermost regions of the nucleus and determine the physical conditions and their driving mechanism. At this stage we aim for the detection of the 183GHz emission, with a future outlook for follow-up high-resolution observations. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-01-28T20:22:44.000 |
| 3673 | 2018.1.00531.S | 0 | Fragmentation and chemical evolution in high mass star formation | The early evolutionary sequence of high mass star formation is still not clear. To investigate this, we propose to map a massive star forming filament within the G10.3-0.1 complex in band 6 and 7 with 12m array, ACA and total power. The clumps on the filament are in different evolutionary stages--from a potential starless clump to ultracompact HII regions--giving us the exceptional opportunity to study key parameters as a function of the evolutionary stage (i.e., time). The main scientific goals are: a) to resolve the clumps down to 0.009pc to investigate how the fragmentation proceeds from less to more evolved clumps, such as the fragment masses and separations, and compare the results with e.g., Jeans and turbulent fragmentation theories. b) to investigate the radial density profile of each resolved core, and establish whether it changes as a function of the evolutionary stages of the cores. c) to investigate the deuterium fraction (N(N2D+)/N(N2H+)) characteristics between the onset of gravitational collapse and more evolved stages. d) to study the kinematics of the high-mass star forming complex, investigate the global collapse from clump to core scale. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-06-27T00:00:00.000 |
| 3674 | 2021.1.00071.S | 108 | Resolving star-forming regions in SMGs at a z=3 proto-cluster core | The advent of ALMA now allows us to dispose the morphologies of the dust continuum emission in submillimeter galaxies (SMGs). Some recent works show that SMGs have complicated structures suggestive of clumps, bars, and spiral arms, which provides new insights on SMG formation. But these current observations are limited to SMGs in general fields, and so environmental dependence is totally uncertain. To this end, we here propose 0.09" resolution imaging of six SMGs in Band7 at a z=3 proto-cluster core. The six SMGs are ubiquitously embedded in IGM filaments traced by Lyman-alpha emission, and four SMGs host a X-ray luminous AGN. Therefore they are ideal targets to investigate rapid growth of galaxies and supermassive black holes (SMBHs) in an extremely gas-rich, dense environment in the early universe. Our aim is (i) to uncover the distribution of the ISM in detail and infer the origin of starbursts, and (ii) to examine co-evolution of SMBH and galaxies in the starburst phase. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2023-08-03T11:01:25.000 |
| 3675 | 2017.1.00441.S | 154 | Exploring gas-rich major mergers in WISE-selected, hot dust-obscured galaxies | WISE-selected, hyper-luminous, hot dust-obscured galaxies (Hot DOGs), representing a transitional phase between the obscured and unobscured QSOs, are suggested to be located at or close to both peaks of SMBH accretion and starburst activities, which are likely triggered by gas-rich major mergers. We have carried out a pilot study of CO(4-3) line observations of three Hot DOGs. Our ALMA Cycle 3 observations find that all three objects in our sample have two or three close components of CO (4-3) lines, suggesting that gas-rich major mergers are main mechanisms for feeding the SMBH accretion and triggering the extreme starburst in most, if not all, hyper-luminous, dust-obscured QSOs. We propose to extend our previous study to a moderate sample of 13 Hot DOGs, in order to explore how often gas-rich major mergers can be found in these objects, which is very helpful for us to understand the main feeding mechanism of luminous high-redshift QSOs. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-01-30T10:34:32.000 |
| 3676 | 2017.1.00624.S | 65 | Diagnose Gas Excitation in the Most Luminous Quasar at Cosmic Dawn | We propose to diagnose the gas excitation status in a quasar-starburst system J0100+2802, the only known quasar host a black hole (BH) more massive than ten billion solar mass at z>6. We have detected strong (sub)mm continuum, [CII], CO (6-5) lines and marginally detected CO (2-1) line in this system. Our ALMA high resolution observation of [CII] shows that the compact [CII] emission does not exhibit ordered motion. Our XMM-Newton observation show that it is a X-ray bright quasar. These observations suggest that the gas of this system may be in an exceptionally high exciting state and provide an unique opportunity to study the impact of strong AGN activity to the physical conditions of interstellar Medium (ISM). We propose to detect CO(7-6), CO(10-9) and CO(11-10) emissions to measure the CO Spectral Line Energy Distribution (COSLED) by combing with our previous observations. We will also observe CO(6-5) at a similar spatial resolution to that of our [CII] observations. These observations will allow us to fully characterize the ISM physical conditions and to improve the dynamical, molecular and dust mass estimates of the host galaxy of the most massive BH in the early universe. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-05-07T20:16:11.000 |
| 3677 | 2016.1.00251.S | 14 | Molecular line polarization in circumstellar envelopes | Although maser observations indicate magnetic fields are ubiquitous around asymptotoc giant branch (AGB) and post-AGB stars, their effect and origin are still unclear. It is often argued that maser observations probe locally enhanced magnetic fields. Only with ALMA will it be possible to study the magnetic field morphology in detail using thermal molecular line polarization. This will finally provide answers about the magnetic field morphology and will allow us to address the decade old debate concerning the apparent large scale field observed in OH maser regions. We propose to map the magnetic field using CO lines around two AGB stars (carbon rich IRC+10216 and oxygen rich R Leo) and the post-AGB star OH17.7-2.0 at 1" resolution. CO polarization around IRC+10216 has previously been observed, at low resolution and sensitivity, using the SMA. However our ALMA observations will for the first time be able to resolve the actual field structure. OH17.7-2.0 has the clearest detection of a large scale field measured with OH maser to date which we will directly be able to compare with the magnetic field determined from polarized CO observations. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2022-11-12T18:58:45.000 |
| 3678 | 2012.1.00912.S | 0 | The Origin of 15N: Synthesis in High or Low Mass Stars? | While it may sound crazy, the origin of one of the seven stable CNO isotopes, that of the rare nitrogen isotope, 15N, is still a puzzle. Traditionally being assigned to low mass stars including novae, recent models of stellar nucleosynthesis, describing the evolution of massive rapidly rotating stars, also permit the production of significant amounts of 15N through mixing of protons into helium burning shells. Direct confirmation of this scenario can be obtained by measuring a low(~100) 14N/15N ratio in the nuclear region of a well developed starburst galaxy, where enrichment due to massive stars must have occurred. We thus propose to confirm a tentative detection of the HC15N J=1-0 line in the nearby starburst galaxy NGC4945. While this could not be done with the SEST, it is a piece of cake for ALMA, requiring only one hour of observing time. | Starbursts, star formation | Active galaxies | 2014-05-02T13:15:22.000 |
| 3679 | 2023.1.01423.S | 0 | Unveiling a warm complex organic reservoir in a giant-planet forming disk | The detection of methanol (CH3OH) in protoplanetary disks is a fundamental step in understanding the organic reservoir available for forming planets and comets. Abundant CH3OH has been detected in two warm transition disks around Herbig stars (HD100546 and IRS48) where the exposed cavity wall in these disks leads to the sublimation of CH3OH ice. These results show that disks can inherit COM-rich ices from the earlier evolutionary stages of star formation. In comparison, CH3OH has so far gone undetected in Herbig disks without such cavities, including the well-studied HD163296 disk which by all expectations should have a COMs reservoir. The lack of CH3OH detected in this disk may be a reflection of the disk structure rather than disk chemistry. Therefore, we propose Band 4 observations targeting CH3OH in the HD163296 disk. At longer wavelengths, the continuum emission is optically thinner and we can trace line emission from deeper into the disk. We will be sensitive to a 10x lower CH3OH column density than detected in HD100546. We will investigate, as already shown for protostars, if dust opacity plays a significant role in hiding the complex organic content in Class II disks. | Astrochemistry | ISM and star formation | 2025-08-09T04:58:10.000 |
| 3680 | 2017.1.01020.S | 58 | Deep [CI] 1-0 observations in the high-redshift Universe: studying the distribution of Dark Matter in galaxies | Understanding the distribution of dark matter and baryons in the high-redshift Universe is of vital importance in order to determine the overall galaxy evolution. The key toward this is to compare the rotation curves of distant galaxies with the local ones. The difference between the two will allow us to understand how the dark matter and the baryonic matter have been evolved across the epochs. Recent SINFONI and KMOS observations suggest that rotation curves of main sequence galaxies show a declining trend pointing to the fact that dark matter played a more minor role in high-redshift Universe than previously thought. We now propose to carry out deep [CI](1-0) observations of three main sequence galaxies located at z~2.2-2.4. These galaxies have been observed in Ha line at radii up to 10 kpc. The proposed observations will allow us to examine the kinematics of gas at much outer radii (~30 kpc) and see whether or not the rotation curves are flat or declining. This study will help us understand the distribution of dark matter and baryons at the peak of star formation activity complementing existing observations. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-05-18T20:42:19.000 |
| 3681 | 2019.1.00607.S | 2 | A Closer Look at the Small Disks | A consensus is emerging from recent high resolution ALMA images that dust substructures are present in most disks. However, our unbiased 0.1 arcsec resolution disk survey of mm-sized dust in Taurus reveals two distinct groups of disks: some are large with gaps and rings, while others are compact and have smooth radial profiles. The large and the compact disks both have inner regions with similar brightnesses, so the lack of rings at large radii for the compact dust disks is not directly caused by sensitivity. We request two sets of observations for five compact disks (20-50 au radius) to test disk formation and evolution. First, we will use CO observations with 0.3 arcsec resolution to measure the gas disk size. Second, we will obtain 0.02 arcsec images of the 1.3 mm continuum to detect any small-scale disk substructures. The size of the gas disk will indicate whether the disk was born small or whether radial drift of mm-sized grains is efficient. The presence of substructures at small radii would demonstrate that drift of mm-sized dust was halted by dust traps; the lack of substructures would indicate an absence of giant planets on scales comparable to our solar system. | Disks around low-mass stars | Disks and planet formation | 2022-12-02T20:50:54.000 |
| 3682 | 2024.1.01465.S | 0 | How dusty star-forming galaxies stay cool with OI63µm at z>4: the first statistical survey of C,N,O line diagnostics | The [OI]63µm line is one of the three brightest fine structure lines in galaxies (together with [CII]158µm and [OIII]88µm), and the only one probing very dense (5x10^5 cm^-3) neutral gas. Therefore, in a dusty ISM, studying [OI]63µm is the only way to uncover components which may not be associated with standard HII regions or PDRs, such as XDR in AGN or unusually dense, compact star-forming regions, which are suspected to be present in IR-luminous galaxies at high redshift. Despite its brightness and importance, the [OI]63µm line has only been detected in a single high-z galaxy, because its rest wavelength requires both sensitive high-frequency receivers and samples of very high z targets. We here propose [OI] 63µm observations in ALMA bands 9 and 10 of a sample of 20 distant strongly lensed dusty star-forming galaxies at 4.2 | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 3000-01-01T00:00:00.000 |
| 3683 | 2023.1.01464.S | 14 | Identifying the Brightest Continuum Sources Accessible to ALMA with the ACA | Molecular gas plays a vital role in the evolution of massive galaxies and their clusters, but the standard approach of detecting it through emission lacks sensitivity. Observing molecular absorption lines can overcome this limitation, allowing for studies on smaller scales and providing insights into the properties of low mass cold gas clouds. So far, nine galaxies have been identified with molecular absorption, revealing information about cloud sizes, velocities, and masses. However, the current sample size is limited, and more absorption lines are needed for a statistically significant understanding. The main challenge lies in the requirement for galaxies to have bright continuum sources, which limits the available targets. To address this, we propose conducting ACA observations of the brightest sources known at frequencies below 10 GHz, where no higher frequency data is available. These observations will identify the brightest targets at the higher frequencies of molecular lines, facilitating future ALMA observations for detecting molecular absorption lines and expanding our understanding of massive galaxies' molecular clouds | Surveys of galaxies | Galaxy evolution | 2025-08-01T18:07:23.000 |
| 3684 | 2015.1.01366.S | 54 | Extreme Red Quasars with Extreme [OIII]Outflows | Red quasars are believed to mark a transition stage in massive galaxy formation when a blowout of gas and dust truncates the initial dusty starburst and reveals a visibly luminous quasar in the galactic center. We identified a population of extremely red quasars (ERQs) with UV--MIR colors like dust obscured galaxies (DOGs) plus other exotic properties that include powerful galaxy-scale outflows revealed by the broadest and most blueshifted [OIII] 5007 lines ever reported (with FWHMs and blue wings reaching 5000 km/s). We propose exploratory observations of two ERQs at z=2.4 to measure their CO(4-3), CO(7-6) and [CI](2-1) emission lines and adjacent continua at ~385 and 625 microns rest. Our broad goals are to characterize the ERQs compared to luminous blue quasars and star-forming SMGs at similar redshifts, test their alleged youth in starburst-quasar evolution schemes, and study the effects of powerful ionized-gas outflows on the host galaxies. We will specifically 1) search for gaseous blowouts or extreme kinematics in the line profiles, and 2) estimate cold dust masses, molecular gas masses, fractions of molecular gas participating in star formation, and star formation rates. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-12-03T20:46:41.000 |
| 3685 | 2021.1.00591.S | 0 | Cloud-scale neutral atomic carbon in the local star-forming galaxy NGC 4321 | We propose to obtain 120 pc resolution CI 3P1-3P0 map of the full molecular gas disk of the nearby star-forming galaxy NGC 4321. We will use the existing multi-wavelength datasets at similar spatial resolution, including H-alpha, FUV, dust extinction, 13CO(1-0), and CO(2-1)/CO(1-0) line ratio maps, as well as GMC and HII region catalogues and galactic sub-region mask (center/bar/arm/inter-arm). These rich ancillary datasets are crucial to determine which map has a more similar distribution to CI, i.e., answering the two-decade-long standing question, "Where does CI come from in galaxies?" We will also apply a stacking analysis using ancillary datasets, and then (1) discuss the impact of the presence of CO-dark molecular gas as functions of GMC properties and environments, and (2) provide "typical" CI properties of molecular clouds in a single star-forming galaxy. The requested CI observations will cover the important parameter space between parsec-scale galactic GMC studies and sub-kpc-scale extragalactic studies, and therefore they will provide a benchmark measurement for all future studies utilizing the neutral atomic carbon line. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2023-06-24T08:30:44.000 |
| 3686 | 2022.1.01460.S | 45 | Millimeter photometry of the disks around Herbig AeBe stars | This is a simple, small survey program to obtain millimeter continuum and CO line fluxes for a well defined sample of disks around 51 nearby Herbig AeBe stars that have not yet been observed by ALMA. This short survey will reveal which disks are bright enough in the continuum and/or line for followup by the community and provide a near complete census (87 out of 91) of all known Herbig AeBe stars within 500 pc of the Sun. To encourage its broad and immediate utility, the data proprietary period will be waived and the flux measurements will be published within 6 months after data delivery. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2024-05-02T17:08:36.000 |
| 3687 | 2018.1.00302.S | 1562 | Fragmentation and substructures of dense cores close to the onset of star formation in the Orion complex | Studies of the fragmentation and substructures of dense cores close to the onset star formation are very important for learning the initial conditions of star formation, and also for testing star formation models like the "turbulent fragmentation" theory. We propose a 1.3 mm continuum survey toward 72 extremely young dense cores in the Orion complex that are at a stage just before or after the onset of star formation, to statistically investigate their fragmentation levels. We will investigate: (a) The presence of substructure in starless cores, (b) The multiplicity of Class 0 objects in protostellar cores, and (c) The effects of the environment on the core fragmentation. Within a reasonable time (~7.8 hrs for 12-m array), the proposed observations will provide a large sample of very young dense cores for investigating the initial conditions close to the onset of star formation, and stimulating more detailed follow-up studies. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-02-02T07:44:32.000 |
| 3688 | 2022.1.00931.S | 540 | Searching for a hidden population of debris disks around massive stars | Debris disks are relics of the planet formation process, and can be used to deduce valuable information about the planetary systems they reside in. Most debris disk studies in the past have focused on relatively Sun-like stars and up to moderately higher masses. However, while >2.5 Msun stars have recently been found to host wide planetary system, they have not been systematically explored for the presence of wide, cold debris disks. Such disks are known to correlate with wide planetary systems from studies around lower-mass stars. Here we propose a survey for debris disks around 60 B-type (2.5-16 Msun) stars in the young Sco-Cen region, using the ACA in standalone mode. The survey will resolve how debris disk frequency scales with stellar mass, and the sample will also allow to test if the disk-planet correlation observed at lower masses also holds for B-type stars. All disks discovered in the survey will be available for more detailed studies in the future, such as (e.g.) higher-resolution morphological studies with the full ALMA array. | Debris disks | Disks and planet formation | 2024-01-24T17:52:42.000 |
| 3689 | 2018.1.00874.S | 76 | The redshifts of the most distant dusty starbursts | Combining data from S2COSMOS (a SCUBA2 large programme covering the full COSMOS field at 850um down to an r.m.s.~0.8mJy/beam) with ALMA observations at 1.2mm we have defined a robust sample of 13 dusty star-forming galaxies at z>5, using the 1.2mm to 850um flux density ratio as a redshift indicator. The two reddest examples are redder than all DSFGs known, including SPT0311-58 at z=6.9, and their 1.2mm/850um flux density ratios are compatible with z>7. Here we propose to confirm their redshifts via 3mm spectral scans with ALMA. The redshift confirmations will allow us to start exploring the properties of dusty star formation at the earliest epochs, as well as investigating the formation of dust back to the epoch of reionization as we approach the era of JWST and ELTs. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2020-08-02T13:28:34.000 |
| 3690 | 2016.1.00456.T | 53 | Magnetar Emission at Submillimetre: Bridging the Gap between Radio and Infrared Detections | Magnetars are strongly magnetized neutron stars that occasionally exhibit remarkable outbursts. A handful of these sources have radio pulsations and infrared (IR) emission detected following outbursts. They show many peculiar properties including flat radio spectra extending to above 100\,GHz with large variability, which are difficult to explain by standard pulsar emission theories. We propose ALMA observations of magnetars during an outburst to measure the spectral and polarization properties at millimeter/submillimeter wavelengths. The results will bridge the gap between the radio and IR detections, help establishing the nature and connection of these emission. Specifically, we wish to identify if both the radio and IR emission originate from the magnetosphere, or if the IR emission arises from X-ray heated debris disks. Understanding this issue will offer essential inputs to build a unification model of magnetars and other classes of neutron stars. | Pulsars and neutron stars | Stars and stellar evolution | 2018-10-09T07:31:37.000 |
| 3691 | 2018.1.00974.S | 30 | Kinematic Diversity at z~1.6: Resolving CO (2-1) in Gas-rich Cluster Galaxies | We have produced some of the first exquisite velocity maps of molecular gas in high-z cluster galaxies using ALMA. These Cycle 5 data, delivered to us within the past month, are rich in information. With only a single pointing, we have spatially-resolved CO 2-1 in 8 cluster galaxies on ~3 kpc scales, and discovered a diversity of kinematic structure. We aim to further exploit this efficient multiplexing strategy by targeting two new clusters at z~1.6. Our proposed observations include 7 gas-rich cluster galaxies with enhanced molecular gas fractions, drawn from Noble et al. (2017), and an additional 17 spectroscopically-confirmed star-forming cluster galaxies, all within 3 ALMA pointings in Band 3. With the first large sample of spatially- and velocity-resolved CO (2-1) in z>1.5 clusters, we will characterize the fraction of ordered versus kinematically-complex galaxies, and compare global molecular gas features to that of the stellar component. As demonstrated with our pilot study in Cycle 5, ALMA is well-positioned to unequivocally map high-z molecular gas in great detail; targeting known gas-rich cluster galaxies at z~1.6 harnesses this potential in <20 hours. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2020-12-25T22:18:40.000 |
| 3692 | 2022.1.00336.S | 25 | Line-of-sight lensing - genesis of small-scale cosmology | Cosmological matter distribution on scales of < 10kpc are important for understanding the nature of dark matter. Galaxy-scale strong gravitational lensing offers us a powerful tool for directly probing small-scale matter distribution. Recent theoretical studies suggest that the major cause of anomaly in flux ratios in some quasar-galaxy quadruple lens systems is small-mass haloes and voids residing in the intergalactic space rather than subhalos in the lensing galaxy. However, the observational evidence is lacking. Since the gravitational effect due to line-of-sight structures is roughly proportional to the comoving distance to the source object, we expect a positive correlation between the amplitudes of convergence and astrometric shift fluctuations resulted from line-of-sight structures and the source redshifts. In order to verify the cold dark matter prediction, we propose to observe several quadruply lensed quasars with extended arcs. From measurements of relative positions of lensed multiple images, we will be able to constrain the nature of cosmological matter density and astrometric shift fluctuations on scales of < 10kpc. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2024-08-17T15:02:53.000 |
| 3693 | 2013.1.01268.S | 8 | 3D mapping of the CO snow surface in a planet-forming disk | Snow lines affect the planet-forming capacity of disks and influence the C/O ratio of extrasolar planets and Solar System bodies. ALMA has successfully imaged the CO snow line in the midplanes of the disks of TW Hya and HD163296 via emission of N2H+ and DCO+. The DCO+ line is ideally suited to map out the 3D structure of the snow surface away from the midplane that is set up up by the combined radial and vertical temperature gradients. DCO+ is only present in a distinct layer that envelopes the CO freeze-out zone, with temperatures between ~21 K (where deuteration becomes significant) and ~19 K (where its parent species CO freezes out). This ALMA proposal aims to use DCO+ to map the CO snow surface throughout the HD163296 disk. In this inclined disk (i~45 deg) emission from different heights is separated in velocity channel maps, as shown by ALMA Science Verification data of CO in the same disk. With the proposed DCO+ observations, we can measure the vertical location of the DCO+ layer, and from there the CO snow surface, across the HD163296 disk. Comparison with CO, H2CO, DCN, and N2D+, obtained simultaneously, places constraints on vertical and radial mixing across the snow line. | Disks around low-mass stars | Disks and planet formation | 2015-09-12T12:35:17.000 |
| 3694 | 2018.1.00536.S | 90 | Revealing Sub-structures in a Very Low Mass Disk | Earth-mass planets have been detected around very low mass (VLM) stars, as TRAPPIST-1. However, the very first steps towards their formation, in particular, grain growth, are still not understood, as the conditions in disks around VLM stars are extremely unfavorable. We propose here a very high resolution and sensitivity study of the dust emission of a VLM star in Taurus (CIDA 1, Mstar~0.1 Msun), where we have detected clear evidence of an inner cavity of radius ~20 AU (Pinilla et al. 2018), as well as indications for mm-size grain trapping. A Saturn-mass planet is required to open such a gap, but it would not be sufficient to trap dust grains and explain the low observed mm spectral index of CIDA 1 (Ricci et al. 2014). Dust evolution models instead predict that dust trapping in VLM stars disks can only occur in multiple dust traps, revealed as multiple rings in millimeter images. The requested observations of CIDA 1 at 0.870 and 2 mm with a resolution of 0.035" (~5 astronomical units) will allow us to spatially detect small-scale structures with size comparable to the disk scale height and directly test dust trapping models. | Disks around low-mass stars | Disks and planet formation | 2020-11-16T16:49:47.000 |
| 3695 | 2016.1.01200.S | 5 | Dissecting the magnetic-field morphology at 1000AU of an O-type YSO - Combining the VLBI and ALMA scales | The importance of B-fields for the formation of massive young stellar objects (YSOs) is still uncertain. Observationally, we have gained considerable knowledge on the large scale B-field properties (0.1pc), but we still lack information about the inner few 1000AU. We have recently obtained the first detailed picture of the gas dynamics and B-field configuration within 1000AU of a massive YSO with VLBI maser observations. Our results show a significant correlation between the velocity and B-field vectors for maser spots of a few AU in size (1mas). Towards this YSO, we also conducted SMA observations at a resolution >0.7" (or 3000AU). We propose ALMA observations, with a resolution of a few 100AU, to bridge the gap between the VLBI and SMA scales. We want to measure the B-field configuration in the inner few 1000AU, through dust polarization, and relate it to the gas dynamics at both the small and large scales from a massive YSO. An ordered B-field morphology aligned across 3 orders of magnitude in spatial scales, down to a massive dusty disk rotating about a massive star, will provide the best possible evidence for a dynamically important role of B-fields in massive star formation. | Disks around high-mass stars | Disks and planet formation | 2018-07-27T07:32:04.000 |
| 3696 | 2017.1.01332.S | 63 | ALMA Deep survey at a z=3.1 proto-cluster core | The environment where galaxies inhabit is expected to play a critical role in shaping their evolution across cosmic time. Therefore the densest environment in the early universe provides a key in comprehending how galaxies grow in their active, forming phase in their life. For such purpose, we obtained a 2'x3' ALMA mosaic at 1.1 mm in cycle 2 toward the core of the z=3.09 SSA22 proto-cluster. The map have uncovered significant environmental dependence; remarkable over abundance of dusty starburst galaxies at the core. Here we propose more than two times deeper 1mm mapping of the field, to uncover dozens of the faint, but representative dusty star-forming galaxies. Combined with deep MUSE mosaic and our band 3 survey, we will quantify the importance of dust-enshrouded star-formation throughly in such a unique environment. The survey will also be a strong blank field survey across the cosmic time. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-12-05T23:28:28.000 |
| 3697 | 2024.1.00776.S | 0 | Investigating localised CO excitation around radio jets in quasar host galaxies | A fundamental outstanding question of galaxy evolution is the impact quasars have on the interstellar medium (ISM) and star formation in their host galaxies. Observations of the molecular gas in these systems play a critical role as it is this gas which is redistributed to both promote star-formation activity and fuel black hole growth in AGN. In particular the excitation and kinematics of molecular gas provide vital insights into the impact of feedback on the ISM. Radio jets in AGN have been observed to affect the surrounding ISM, impacting on the kinematics and excitation in low Carbon Monoxide transitions (Jco < 3). Here we propose a pilot study of the resovled CO(6-5) in 2 quasar host galaxies at z < 0.2, which have complementary resolved CO(2-1) and CO(3-2) observations with ALMA at a resolution of ~0.3 arcsec. These targets also have complementary multiwavelength data showing a range of radio jet properties and outflow kinematics. From this proposal, the localised impact of radio jets on the ISM will be analysed, particularly the impact on CO excitation. Targeting CO(6-5) will allow for a focus on CO transitions which are more influenced by AGN due to the higher energies. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 3698 | 2022.1.01134.S | 34 | Investigating Disk Disruption and Mass Outflow Triggered by Binary Orbital Motion: The Important Case of T Tauri South | T Tauri is the eponymous member of it's class of young sun-like stars. This remarkable triple star system has become a veritable laboratory for modeling dynamics in young star multiples. Imaging of its outflows reveals periodic mass ejections. Correlation of the outflow kinematics with the historical orbit timing of T Tau South binary (period 27 yr) suggests a fascinating prospect: the launch of the southern outflow ejections may be nearly contemporaneous with the close-binary periastron passage. As such, T Tau provides an amazing opportunity to study tidal disk disruption and launch of a new outflow with the upcoming binary periastron passage in 2023. With 10 hours of ALMA time, we propose to make a new measurement of the T Tau system near to the 2023 periastron passage. This will provide a critical opportunity to measure disk disruption and study the circumstellar gas and dust (inner and circumbinary disks, jets/outflows). Cycle 9 overlaps with the periastron time frame, hence this project is time critical. The next opportunity to study T Tau periastron passage at this level will be in 27 years. | Outflows, jets and ionized winds | ISM and star formation | 2024-01-27T18:17:01.000 |
| 3699 | 2021.1.01417.S | 186 | Molecular gas streams around the intermediate-mass black hole candidates in the Galactic center | Intermediate-mass black holes (IMBHs) are key objects to understand the origin of supermassive BHs (SMBHs). However, definitive evidence for IMBHs has not been obtained yet. Recently, the discovery of interesting molecular gas streams has been reported near the Galactic nucleus. These sub-pc scale streams show clear orbital motions around two invisible gravitational sources, which may be massive IMBHs or highly dense clusters mainly consisting of dark stellar remnants such as neutron stars and stellar-mass BHs. Here, we propose high-resolution (0.2 arcsec) molecular line and continuum observations toward the gas streams in ALMA band 6 and 7. The principal objective is to probe mass distribution of the putative gravitational sources and examine the IMBH hypothesis by investigating the detailed kinematics and physical conditions of the streams. We also aim to resolve mysterious ultra-compact (d<0.04 pc) clumps with extremely broad velocity widths (dV~50 km/s) located around the two IMBH candidates. This project would potentially fill the "missing link" between stellar mass BHs and SMBHs, contributing to further understanding of galactic evolution. | Galactic centres/nuclei | Active galaxies | 2023-04-22T08:40:49.000 |
| 3700 | 2018.1.00861.S | 99 | The Shape of Water: Dissecting the ISM in high-redshift dusty starbursts with luminous water emission lines | H2O lines provide a unique diagnostic of the star-forming regions of high-redshift dusty galaxies. Strong gravitational lensing boosts ALMA sensitivity and angular resolution, enabling comprehensive studies of the high-redshift sources down to sub-kpc scales. Our previous studies of global H2O lines has shown that H2O emission is ubiquitously bright in submillimeter galaxies (SMGs). Our modeling shows that the H2O lines originate from highly obscured infrared-luminous regions tightly correlated with star formation. To fully unleash the diagnostic power of H2O lines, we here select the best equatorial lensed SMGs at z~2-4, and propose to image J=2,3,4 H2O lines with 0.2"-0.3" resolutions. Through lens models, we will be able to resolve the H2O and dust continuum emission at sub-kpc scales intrinsically. The sample will triple the total number of sources with high-resolution images of the H2O emission in dusty starbursts at any redshift. The multiple H2O lines, together with the bonus CO/[CI] lines, will allow us to further constrain the structure and properties of the heavily obscured star-forming regions and help us understand the star formation conditions in high-redshift SMGs. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-12-10T16:40:48.000 |
| 3701 | 2021.1.00912.S | 14 | Hydrogen Masers as a Tool to Understand Dying Stars | The spectacular characteristics of the Mz 3 nebula have been eluding the astronomers for years. The core structure of this object, where all the structures were originally formed, the mechanisms acting there, and its central powering source (or likely sources) are still poorly known. A more precise model for the structure in the core of Mz 3 is necessary to improve our understanding of the mechanisms of outflow ejection and morphology formation. Recent Herschel observations revealed the unusual emission of hydrogen recombination maser lines in its far infrared to submillimetre spectrum. The hydrogen maser emission only occurs in a narrow range of physical conditions and from its characteristics we can determine physical conditions, geometry and size information. Here we propose to use the hydrogen maser emission at higher spatial and spectral resolution as unique tool to study the very dense nuclear structure of this object, in regions not accessible by other common types of emission diagnostics. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2022-11-24T12:07:08.000 |
| 3702 | 2015.1.00192.S | 88 | Hunting for gaps in HEABE disks | Gaps in disks are a signpost of disk dispersion and planet formation, but finding disk gaps is challenging. Spectral Energy Distribution (SED) studies of the dust disks do not provide unequivocal evidence for gaps, especially in disks around higher mass Herbig Ae/Be stars. Recently it has been suggested the Herbig stars classified as flaring are in fact disks with developing or fully cleared gaps. We propose to test this hypothesis by imaging three flaring HAEBE disks for which strong indirect evidence of such gaps exists, but for which no gaps have been resolved using direct imaging. Using the 13CO, 12CO and C18O J=2-1 isotopes, we also measure the gass mass inside the gaps to constrain the gap opening mechanism, and in the outer disk to measure the amount of flaring of the gas disk. This is a modified resubmission of proposal 2013.1.00658.S. This proposal uses another band (band 6 in stead of 7) with slightly coarser spatial resolution but a 3 times higher line sensitivity. Since resolving the gaps in the continuum is the main science driver of this proposal, any observations made during cycle 2 of this program do not have to be repeated for cycle 3. | Disks around high-mass stars | Disks and planet formation | 2017-11-17T20:34:03.000 |
| 3703 | 2019.1.01639.S | 7 | High-mass star formation told by water masers: disk-winds or YSO multiplicity ? | The processes leading to the formation of high-mass stars are still largely unknown. Although, as predicted by star formation models and supported by ALMA observations, accretion disks and jets should play a fundamental role, it is still to clarify the physical connection betweem mass accretion and ejection. Moreover, the very high (> 80%) binary fraction of OB stars requires a high level of mass fragmentation, which might occur either at large scales in the turbulent collapsing cores or at small scales in the massive protostellar disks. In our targets, the high-mass YSOs G011.92-0.61 and G035.02+0.35, previous VLBI masers and ALMA thermal observations strongly suggest the presence of either 1)a disk-wind, or 2)a binary system of high-mass YSOs separated by ~500au. The proposed ALMA observations aim, for the first time, to either 1)resolve the launching region of jets in high-mass YSOs (and test the disk-wind models), or 2)detect disk fragmentation on scales of 100au (and verify that it is a viable route for high-mass YSO multiplicity). In either scenarios, the results will provide a critical test bed for current models of high-mass star formation. | High-mass star formation | ISM and star formation | 2022-10-27T04:11:35.000 |
| 3704 | 2018.1.01449.S | 3 | Magnetic fields from infrared dark clouds to hot molecular cores | The importance of magnetic fields during the formation of (high-mass) stars is an ongoing topic of strong discussion. While previous observatories could only scratch the surface, with ALMA we can now investigate the impact of magnetic fields during the evolution of high-mass star-forming regions. Based on our recent dust polarization study of the high-mass starless region IRDC18310-4 (Beuther et al. 2018), we want to extend magnetic field investigations to a (small) sample of one infrared dark cloud, one high-mass protostellar object and one hot molecular core. Setting these data into context with literature studies and our magneto-hydrodynamic simulations of collapsing massive gas cores (Koelligan, Kuiper et al.; Soler & Hennebelle), we will address the following topics: (a) What is the morphological structure of magnetic fields and how does it evolve with time? (b) We will derive crucial parameters like magnetic field strength and turbulent-to-magnetic energy ratio, and set these into context with the evolutionary sequence. (c) Observing simultaneously the CO Goldreich-Kylafis effect, we will investigate the magnetic field in the outflows and study their evolution with time. | High-mass star formation | ISM and star formation | 2020-11-19T09:53:52.000 |
| 3705 | 2018.1.01812.S | 32 | Deep [C II] Imaging of a Strongly-Lensed SMG-LBG pair at z=4.7 | Recent ALMA [C II] 158 micron observations of 5 | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-12-18T19:03:11.000 |
| 3706 | 2023.A.00017.S | 10 | First in-depth characterization of a redshift twelve galaxy | We request Band-8 and Band-6 observations, probing the [OIII]52um and the [OIII]88um lines, in the brightest spectroscopically-confirmed galaxy at redshift twelve. By targeting two transitions from the same ion, ALMA is uniquely suited to characterize the ISM properties of this extreme system. These observations will put tight constraints on the gas densisty of this galaxy that, in combination with rest-frame UV/optical emission lines already hand, will enable the most in-depth characterization of an early galaxy to date. Characterizing the excitation conditions in this extreme galaxy is critical to understand whether it is powered by early AGN activity or by efficent star formation triggered in the unique conditions of the early Universe. Regardless of the outcome, this would represent a step forward in understanding the earliest phases of galaxy formation. This is the brightest ultra high-redshift galaxy confirmed to date and the best target to demonstrate ALMA's capabilities to detect and characterize galaxies in the early universe. | Lyman Break Galaxies (LBG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2024-11-13T19:03:31.000 |
| 3707 | 2015.1.00048.S | 38 | A study of stellar mergers through measurements of their disks and outflows | What kind of systems do stellar mergers produce, as seen years to decades after the coalescence? We propose to answer this question by observing emission of circumstellar dust and gas around V1309 Sco & V4332 Sgr, two objects that underwent a stellar merger event before our eyes in 1994 and 2008 (in real time!). We propose observations of the continuum and in molecular lines with the main aims: (1) to constrain masses and physical sizes of dusty disks which were formed in those objects just after the merger, and (2) to trace the molecular material which was dispersed during the eruption or which is stored in the coolest parts of the disks; (3) account the angular momentum stored in the disk and the stellar remnant. These observations are crucial for understanding the physics of stellar collisions and their aftermath. By this, they are important for understanding evolution of close binaries, especially those undergoing the common-envelope phase. | Cataclysmic stars, Transients | Stars and stellar evolution | 2017-07-27T14:47:13.000 |
| 3708 | 2019.1.00219.S | 6 | What is the Heating Source of the Dusty Streamers in the High Redshift Obscured Quasar W2246-0526? | At z = 4.6, W2246-0256 (W2246) is the most luminous obscured quasar known, and it is experiencing a multiple-merger event. Recent ALMA 212um rest-frame continuum observations have revealed not only that W2246 is surrounded by at least 3 companion galaxies, but also that these are connected to the central source by dusty structures resembling tidal streamers, extending over at least 35 kpc in length. This is the first time that direct morphological evidence is presented for a galaxy merger at such high redshift. The energy source responsible for the dust heating in these streamers is, however, unknown. Here we propose to obtain deep ALMA band 4 observations of the CO(7-6) emission line in the W2246 streamers, with which we will distinguish between the two main possible heating mechanisms: in-situ star formation or direct illumination from the central AGN. These observations will showcase the extreme environments that the most luminous galaxies may be experiencing in the early universe, informing theoretical models of galaxy evolution --that will have to reproduce the physical conditions observed in this exceptional merger system, as they occur in nature. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2022-09-24T20:43:52.000 |
| 3709 | 2017.1.00569.S | 96 | Solving the Discrepancy between Spectroscopic and Dynamical Stellar Mass Determinations of Lupus YSOs | We analyzed the archival data of the ALMA survey in 13CO (3-2) toward 89 protoplanetary disks in the Lupus star-forming region, and obtained dynamical stellar mass estimates for 45 young stars in the survey. We found that there is a group of young stars having their spectroscopically determined stellar masses systematically lower than our dynamical estimates. It is possible that systematic uncertainties are affecting the spectroscopic determinations. However, due to the low S/N of the current ALMA data, the origins of the discrepancy between the dynamical and spectroscopic estimates are unclear, and the accuracy of our dynamical estimates is not sufficient to provide a meaningful benchmark against the spectroscopic determinations. Thus, we propose ALMA observations in CO isotopologues toward four young stars having the best spectroscopically determined stellar masses in the Lupus survey. With the proposed observations, we aim to provide precise dynamical stellar mass estimates as benchmarks for pre-main sequence stellar models adopted in the spectroscopic stellar mass determinations. | Disks around low-mass stars | Disks and planet formation | 2019-10-27T10:47:16.000 |
| 3710 | 2021.1.00390.S | 13 | Identification of New Pre-BD Cores and Study of Mass Transfer to the Cores | We propose to observe four pre Brown-dwarf (BD) core candidates, labeled as c2, c3, c4 and c5, in the Serpens Main region. BDs have too little mass to fuse hydrogen. Whereas theoretical studies suggest several scenarios for BD formation (e.g., turbulent fragmentation), observational studies have not confirmed BDs in the prestellar phase, so-called pre-BD cores, except for only one case. The proposed study will thus be the first step to study the initial condition of BD formation without sample bias. The targets were identified in ALMA archival data. The virial analysis for c3 and c5 using the C18O J=2-1 line and the Jeans analysis for c2 to c5 using the 1.3 mm continuum emission suggest that they are gravitationally unstable or marginal. The cores are also associated with a dusty filamentary structure, and a velocity gradient along it is detected in the N2H+ 1-0 line using the CARMA, which may give a hint of mass supply to or robbery from the pre-BD core candidates. We will examine gravitational boundness, future growth, and turbulence of c2 to c5, by observing them in the N2H+ 1-0 and 13CO 1-0 lines at an angular resolution of 1 (440 au). | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-06-07T05:47:45.000 |
| 3711 | 2016.1.00243.S | 25 | Confirming Deeply Embedded Protostellar Population in the Central Molecular Zone | The inner 500 pc of our Galaxy, known as the central molecular zone (CMZ), is a star-forming environment with extreme physical properties. Despite its large reservoir of dense gas, the CMZ appears to have a much lower current star formation rate than what the Kennicutt-Schmidt relation predicts. Theories have suggested an episodic star formation cycle which is at its near-minimum now. Our VLA and SMA observations towards a sample of four CMZ clouds have detected a population of protostellar candidates, traced by gravitationally bound dense cores and H2O masers. They may suggest an increase of current star formation than in the last few million years, consistent with the episodic star formation mode in the CMZ. However the existing data cannot confirm definitely the protostellar nature of these candidates. We propose to use ALMA, with its unprecedented capability of high sensitivity and high dynamic range, to observe these protostellar candidates. The project, aiming at detecting compact CH3CN emission from natal hot molecular cores, will confirm or reject the presence of embedded protostars. The new observations will provide us a vision of the episodic star formation in the CMZ. | High-mass star formation | ISM and star formation | 2018-11-13T00:00:00.000 |
| 3712 | 2019.2.00037.S | 368 | An ALMA CO(2-1) ACA Survey of Luminous Infrared Galaxies in GOALS | We propose an ACA CO(2-1) survey of a complete sample of GOALS Luminous Infrared Galaxies (LIRGs) in the declination range = +20 to -40 degrees. LIRGs span the transition from main sequence galaxies to extreme starbursts, and their high-z counterparts dominate the IR density at z > 1. These new ALMA data will have resolutions comparable to pre-existing JVLA, GALEX, Spitzer and Herschel data, making it possible to measure gas kinematics and both the star formation rate and molecular gas surface densities on scales of ~ 2 kpc. When combined with ancillary spectroscopic diagnostics of the dominant ionization processes, the proposed observations will allow us to investigate the conditions under which star formation is most efficient and under which outflows are driven. No such CO dataset presently exists. This proposal sets the stage for high-resolution observations at the scale of GMCs with the ALMA 12m Array. Further, the sample is spread over the entire RA range, making this an ideal filler project. The sample size and completeness, breadth of multi-wavelength GOALS data, and the accessibility of the sample from telescopes in both hemispheres, ensures the legacy value of this study. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2022-10-01T06:50:38.000 |
| 3713 | 2022.1.01591.S | 15 | The nature of the water gigamaser in TXS2226-184: the ALMA view | We propose for ALMA band 5, 7, and 6 observations of the nuclear region of the elliptical/S0 galaxy TXS2226-184, where the first 22-GHz water gigamaser was detected in 1995 and only recently associated with the nuclear jet/outflow or, alternatively, with the accretion disk around the central engine of the galaxy. The proposed measurements aim at detecting and locating, for the first time, 183 and 380\,GHz water maser emission and dense molecular gas signature (HCN and HCO+) in the nuclear regions of TXS2226-184. Such a result has the potential to yield a confident answer to the origin of the water maser emission and make the comparison possible between the cm and mm-maser characteristics, thus to infer the possible difference excitation condition within the nuclear gas. | Galactic centres/nuclei | Active galaxies | 2024-11-07T20:40:45.000 |
| 3714 | 2019.2.00096.S | 44 | A study of molecular clouds interacting with cosmic rays in the supernova remnant IC 443 | Supernova remnants (SNRs) are thought to accelerate cosmic rays (CRs), and yet its acceleration mechanism is not fully understood. In particular, the CR acceleration efficiency is still a matter of debate. IC 443 is one of the very few SNRs where the gamma-ray emission produced via collisions between CR and interstellar protons is identified, being an excellent laboratory to study CR acceleration in SNRs. Recently we find some evidence for presence of the 0.1-pc scale clumpy molecular clouds in IC 443 with the near-infrared [FeII] and H2 observations. The clumpy clouds may allow CR protons to interact with large amounts of the interstellar protons in IC 443. However spatial resolutions of the current available CO maps of IC 443 are not high enough to resolve such clumpy clouds, preventing us from precisely estimating the interstellar proton density, an important parameter to evaluate the CR energy and thus the CR acceleration efficiency in SNRs. In order to evaluate the CR acceleration efficiency in IC443, with ALMA, we aim to investigate morphologies of the clouds in IC 443 at the 0.05-pc scale for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-04-13T07:41:43.000 |
| 3715 | 2024.1.01134.S | 0 | A robust metallicity measurement of a z=5 star-forming galaxy based on the combination of far-infrared and optical lines | Accurately determining gas-phase metal abundances of galaxies is critical as metals strongly affect the physics of the interstellar medium. Presently, most of the gas-phase abundance indicators rely on emission from bright optical lines, whose emissivities are highly sensitive to the electron temperature. Alternatively, direct-abundance methods based on auroral lines require challenging observations. Here we propose a novel and powerful alternative method that uses the combination of the [OIII] 52 um transition and hydrogen recombination lines to derive metallicities that are nearly insensitive to the assumption of electron temperature. Our proposed target, the star-forming galaxy HZ10 at z=5.6, is an ideal source for this pilot observations because it is bright, with well-sampled spectral energy distribution based on multiple ALMA band observations, and has JWST/NIRSpec observations of the main rest-optical lines. These proposed observations will yield a robust measurement of metallicity in HZ10, setting a benchmark for future high-z galaxy metallicity studies based on ALMA and JWST. | Lyman Break Galaxies (LBG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 3716 | 2018.1.00190.S | 116 | Unveiling the central system and its driving jet in the water fountain W43A | One of the most mysterious questions in the astrophysics is the driving source of a highly collimated fast jet from an evolved stellar object. Unveiling the object will enable us to understand the current evolutional status of the star hosting such a stellar jet. The kinematical time scale of the jet traced by 22 GHz water masers (water fountain) is very short (<100 years), likely caused by the episodic outbursts indicated by the observed point symmetric pattern of water masers and CO emission in the jet. The decadal jet evolution may be traceable by monitoring observations with ALMA through its operation lifetime using the promising millimeter line tracers of the energetic and episodic stellar mass loss and the ignitions of photodissociation and photoionization of the circumstellar envelope and the jet. They will lead us to predicting the complicated morphology of the formed planetary nebula. This ALMA proposal focuses on W43A, which is the prototypical water fountain and still exhibits copious mass loss with circumstellar hydroxyl and silicon monoxide masers. A new episodic outburst and the first moment of photodissociation or photoionization are expected to be visualized. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2020-09-10T11:35:45.000 |
| 3717 | 2017.1.01013.S | 16 | Physical and Chemical Changes at a Few Ten au Scale in IRAS 16293-2422 Source B | IRAS 16293-2422 is a Class 0 protostellar binary, and is known to harbor a hot corino characterized by rich complex organic molecules (COMs). Recently, we found an infalling-rotating envelope (IRE) in Source A by analyzing the ALMA data, and identified its centrifugal barrier (CB) by using a ballistic model. A drastic chemical change is found in Source A: OCS traces the IRE, COMs the CB, and H2CS both the IRE and the Keplerian disk inside it. We also analyzed their distributions in Source B, and confirmed a similar chemical differentiation. Although COM lines seem to highlight the CB, it is not resolved enough. Moreover, the high dust opacity toward Source B in Band 6 seem to conceal the detailed structure in the vicinity of the protostar. To overcome these situations, we here ask for higher angular resolution (0".15) observations at the lower frequency (Band 3). Since the rich COM lines in Source A seem to come from the CB, characterizing the structure around the CB in Source B will provide us with a clue to understanding the origin of the hot corino chemistry. Hence, these observations have a substantial impact in astrochemistry and astrophysics. | Low-mass star formation, Astrochemistry | ISM and star formation | 2021-02-13T03:39:55.000 |
| 3718 | 2011.0.00470.S | 0 | Structure of the Debris Disk around the Solar Analog HD 107146 v0.4 | We propose to image the dust continuum emission from the debris disk that surrounds the star HD 107146. This star is of interest since it has the same spectral type as the Sun, but at an age of 80-200 Myr, it reflects the conditions in a primitive debris disk around a solar analog. Moreover, the debris disk is 3-5 times brighter at submillimeter wavelengths than any other known debris disk around a G-type star. Thus HD 107146 presents a unique opportunity to image a debris disk around a young solar analog at high sensitivity and angular resolution. The debris dust is known to be distributed in a broad (80-120 AU wide) ring with a mean radius of about 110 AU, and is thus a larger and more luminous version of the Kuiper Belt. The proposed ALMA observations will detect emission from the large dust grains in the disk, the dynamics of which are affected mainly by collisions and gravitational forces. Any asymmetries observed in the submillimeter continuum emission therefore reflect structural asymmetries in the disk, possibly from gravitational perturbations from orbiting planets. | 2014-02-27T21:24:00.000 | ||
| 3719 | 2016.1.00967.S | 108 | The CO Excitation of Milky Way Progenitors at z=1.2-1.3 | We have recently used ALMA to make the first measurements of CO(3-2) emission in "typical" (lower-mass) star-forming galaxies at z=1.2-1.3. These galaxies were carefully selected from deep near-IR imaging to have the stellar mass (Log M*/Msol = 10.2) and SFR (20 Msol/yr) of Milky Way progenitors. They sit on the star-forming main sequence, and are therefore characteristic of the star-forming population. Here, we propose ALMA observations of CO(5-4) and CO(2-1) for three of these galaxies. The galaxies' detected CO(3-2) emission implies large reservoirs of molecular gas, where the gas mass exceeds the stellar mass. This interpretation is hindered by the complete lack of constraints on the gas excitation, and this could lead to errors in the conversion to total gas mass. We will measure the CO spectral line energy distribution (SLED) from the new CO(5-4) and CO(2-1) data, and existing CO(3-2) data, providing the first measurement of CO excitation in lower mass star-forming galaxies at these redshifts. We will use the CO SLED to constrain the physical conditions in the gas, and test for variations compared to the more massive galaxies that have been studied previously. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2017-12-14T16:12:42.000 |
| 3720 | 2024.1.00510.S | 0 | ALMA follow-up of JWST-resolved massive stellar winds in Westerlund 1 | Despite their short lives, massive stars play a fundamental role in the evolution of the Galaxy, having an outsized impact on their surrounding environments over wide spatial scales. A major role is played by their winds, which can reinject material into the ISM and/or nearby star--forming regions to promote/hinder star formation. JWST/MIRI observations of the nearest massive star cluster Westerlund 1 (GO-1905, P.I. Guarcello) have brought into impressive detail new resolved images of high mass winds. We propose to image the 6 brightest outflows detected with JWST, and follow up 1 further source (with archival ALMA data consistent with a wind). We will measure their outflow mass loss rates, and the kinematics of their winds. As yet, just one Westerlund 1 source has had its outflow characterised with ALMA (W9 in band 3; Fenech+17). Our proposal will provide the deepest maps of 7 winds in this region with identical angular resolution to JWST. With high spectral resolution, we will provide the first spectro-spatially resolved detections of hydrogen recombination line emission from H30-alpha, and probe the physics in operation towards this diverse sample of massive stellar winds. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2025-10-25T16:44:36.000 |
| 3721 | 2018.1.00010.S | 28 | The detached shells around the carbon AGB stars DR Ser, V644 Sco, and S Sct | We propose to observe the detached shells around the carbon AGB stars DR Ser, V644 Sco, and S Sct in CO(1-0). The shells were created during the high mass-loss rate phase of a thermal pulse (TP). The observations will allow us to determine the evolution of the mass loss from AGB stars during and after a thermal pulse. The amount of mass lost during the TP cycle is critical, as it limits the number of TPs an AGB star experiences, and hence the yields to the ISM. We will observe the shells and the extended circumstellar envelopes at a spatial resolution of 1". The spatially resolved observations will be used as constraints in models of lower-resolution observations of multiple CO transitions. The shells span the entire age range of known detached shell sources, allowing us to constrain the mass-loss rate shortly after the thermal pulse, and to follow the evolution of the shells until they get photodissociated after 10000 years. The proposed observations will yield the most detailed view of the evolution of the mass loss throughout the TP cycle on the AGB, and will constrain critical aspects of late stellar evolution, and hence of the chemical evolution of stars and the ISM. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2020-01-10T23:49:07.000 |
| 3722 | 2016.1.00753.S | 22 | Explaining the puzzling SiO emission toward G331.639+00.501: a high-mass starless cluster-forming clump | A remarkable discovery of recent Galactic Plane surveys, was the presence of quiescent, starless clumps exhibiting widespread SiO emission. These clumps appear dark in the infrared, have low dust temperatures (<20 K) and show no signs of current star formation. Since the SiO emission is usually associated with outflows from newly formed stars, the detection of SiO toward quiescent starless clumps is unusual. We propose to study G331.639+00.501, a quiescent high-mass proto-cluster candidate that exhibits widespread SiO emission. Using ALMA, we will obtain a mosaic of the SiO and dust emission across it to determine whether the SiO emission is due to: (1) outflows from a distributed population of low-mass proto-stars, implying perhaps that low-mass stars have already formed within the clump OR (2) large scale flows due to a recent cloud-cloud collision, which would suggest that we are witnessing clump formation. In either case, these observations will reveal the small-scale distribution of SiO emission toward this cluster-forming clump. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-05-24T00:00:00.000 |
| 3723 | 2016.A.00029.S | 3 | Monitoring the chromosphere of the AGB star W Hya | Shocks, convection and stellar activity have a major impact on the circumstellar chemistry and mass loss of evolved AGB stars. Surface and extended atmosphere studies of these stars have so far been limited to the visual to near-infrared wavelength ranges, with limited imaging capabilities, or the marginal resolving power offered at radio wavelengths. Using ALMA long baselines, we have resolved exquisit details of the stellar atmosphere of W Hya. We show numerous hotspots close to the actual stellar photosphere, and a hot gas layer with temperature >5000 K. This firmly proves the existence of a (likely shock-heated) chromosphere that shows stellar activity. Only ALMA can image this activity, as at other wavelengths opacity sources limit our view on the stellar surface! Here we propose a second epoch of W Hya observations near maximum light. Such time resolved observations are crucial for modeling the structure of AGB atmospheres, as our current results challenge almost all available models that underlie our understanding of AGB mass loss. This opportunity is only available during ALMA Cycle 4! | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2018-08-01T14:10:59.000 |
| 3724 | 2019.1.01167.S | 14 | Impact of interactions in the compact triple system HT Lup | To investigate the impact of close encounters and binary interactions to the process of planet formation in protoplanetary disks, we propose to obtain continuum, 12CO and 13CO J=3-2 line observations of HT Lup, a triple stellar system where a protoplanetary disk has been detected around each star. HT Lup is the ideal candidate to test our understanding of protoplanetary disks in multiple systems and their evolution, since spiral structure and disk truncation have been observed in this system, both expected to arise from close encounters. Current gas observations of low-energy rotational states are contaminated by the surrounding cloud, preventing us from searching for non-Keplerian signatures of the interaction. Observing at higher angular resolution and with gas tracers at higher energy levels will enable us to study the dust distribution and the kinematics of these very compact sources (60au, 5au and 9au in diameter, with the closest companions at only 25au of projected distance), constraining also their interaction for numerical modelings. | Disks around low-mass stars | Disks and planet formation | 2022-08-20T16:47:57.000 |
| 3725 | 2015.1.00695.S | 13 | Star-forming clumps after the peak epoch of star formation | We propose a high-resolution CO line and dust continuum imaging program of a sample of six massive star-forming galaxies at z=0.7 in order to investigate in detail the star formation processes and the fate of the star-forming regions after the peak epoch of star formation. We will derive the mass distribution, the kinematics and the velocity dispersion of the molecular gas with an unprecedented resolution at this redshift, namely 0.05" or 300 parsecs, thus reaching the scales of the star-forming regions themselves. This will enable us to characterize star formation on subgalactic scales, notably through a spatially-resolved Kennicutt-Schmidt relation, to observe the inner morphology of the disk, and to test the virialization of the star-forming clumps. This study is meant as a high-resolution step forward of the IRAM PHIBSS and PHIBSS2 programs, which investigate early galaxy evolution and star formation from a larger statistical sample of about 200 sources at different redshifts but with lower resolution. ALMA resolution and sensitivity will allow us to reach sub-kpc scales, which is crucial to our understanding of the transitional period of the winding-down of star formation. | Starbursts, star formation | Active galaxies | 2016-12-17T13:39:41.000 |
| 3726 | 2017.1.00616.S | 46 | Probing Molecular Gas throughout the Quenching Sequence | A major puzzle in galaxy-evolution research is how massive galaxies at high-z cease to form stars efficiently and become quenched. To date, no molecular-gas observations exist for quenched galaxies at z~2, despite their ability to distinguish between possible quenching mechanisms. We propose deep ALMA Band 3 observations aimed at detecting CO in the three best-studied massive quenched galaxies (MQGs) at z~2 as a pilot study. All targets are gravitationally lensed, and deep multi-band HST imaging as well as deep VLT or Keck absorption-line spectra are available. Prompted by indirect evidence that z > 2 MQGs may possess significant amounts of cold gas, we propose to obtain the first direct detection of molecular CO emission with ALMA. Our targets are ideally suited for this purpose, as gravitational lensing allows us to probe 4-12x fainter intrinsic luminosities. These observations will allow us to (1) provide first constraints on the CO excitation in z~2 MQGs; and (2) constrain the mechanisms responsible for quenching in these MQGs. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2019-04-01T13:22:56.000 |
| 3727 | 2016.1.01231.S | 85 | Characterising super-giant molecular clouds properties in star forming galaxies at z=2-3 | Observations of giant molecular clouds (GMCs) provide important insights in the star formation physics. Measuring physical properties of these GMCs require to probe <100pc scale. While this scale and smaller ones are easily reached with current submm interferometer in the local Universe, probing this maximum size at higher redshift still represents a challenge. The Eyelash, a distant galaxy strongly lensed by a massive cluster, allowed us to probe for the first time such maximum scales at z=2.3. In this program, we add 4 new strongly magnified sources in the 2.3 | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2018-11-13T06:41:07.000 |
| 3728 | 2018.1.00251.S | 86 | Cold cases: molecular gas and outflows in two unique X-ray obscured Quasars at z~1.5 | Given the relevance of multi-phase outflow phenomena in AGN feedback models, the study of the gas content in high-z AGN with outflows, and the relation between winds seen in various gas phases, are being investigated over an increasingly large number of sources. We have isolated three obscured quasars at z~1.5, optimal targets for studies of the ISM conditions of AGN host galaxies. In our pilot project on one of them, XID2028, we demonstrated that AGN feedback depletes the gas in the host and that spatially resolved outflow studies are feasible at z>1. We propose to complete with ALMA the study of molecular gas in the other two systems. Our primary goals are to assess, whether: 1) the ionised wind has a counterpart in the molecular phase, and how they compare together; 2) the massive wind has an impact on the cold gas reservoir; 3) a fast rotating disc of dense molecular gas is sitting at the centre of the host. Overall, the observations will provide unprecedented constraints on the most interesting systems in a redshift range critical for AGN-galaxy co-evolution, resulting in a crucial step forward in observational studies of ouflow phenomena and their impact on the host. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2020-08-08T20:10:58.000 |
| 3729 | 2022.1.00386.S | 0 | Polarization reversal in the disk and envelope around a 20 Msun YSO | ALMA has revealed new and in some cases unexpected results regarding the dust polarization in circumstellar disks. We propose to perform multiband full polarization observations towards a very massive, hot and dense disk surrounding a 20 Msun Young Stellar Object: GGD27-MM1. ALMA 1.14 mm linear polarization observations revealed a polarization reversal at 140 au radius, which we will measure as a function of wavelength. The multiband set will additionally constrain the maximum size of the grains by analyzing the change of the self-scattering emission. A third main goal is to interpret the azimuthal pattern found in the outer disk. We will study the polarized emission using state of the art radiative transfer models. Finally, the multiwavelength high-angular resolution data sets will provide an insight in the opacity, temperature and surface density spatial distributions in one of the closest massive circumstellar disks. | Disks around high-mass stars | Disks and planet formation | 2025-09-30T15:43:36.000 |
| 3730 | 2021.1.00586.S | 17 | The First Map of the Star Formation in a Galaxy at z>3 | The Science Verification observations of the z=3.042 lensed galaxy SDP 81 produced spectacular maps of the ISM with a resolution of ~50 pc, revealing massive clouds of gas in a collapsing disk. The early epoch and the rapid global star-formation rate imply that we are seeing this galaxy during its formation phase. In order to investigate the physical relationship between the ISM and the star formation, we need an independent map of the star-formation rate with a similar resolution. Although there are published star-formation maps for galaxies at z>3, they have all been produced from maps of the ISM by assuming a constant star-formation efficiency and are therefore of no value for investigating star-formation physics (they are essentially scaled maps of the ISM). The only practical method for mapping the star formation in a galaxy at z>3 is to combine ALMA Band-10 observations with ALMA observations in lower bands to map the bolometric dust luminosity. We propose to use this technique to produce the first ever map of the star-formation rate in a z>3 galaxy, which will have a resolution of only 100 pc, the size of a giant molecular cloud in our galaxy. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-12-26T14:11:41.000 |
| 3731 | 2019.1.00193.S | 24 | Astrochemical confirmation of a circumplanetary disk | ALMA observations of the dust and gas in protoplanetary disks have rapidly brought unprecedented insight into the planet formation process. In Booth et al. (2018), we presented the first detection of the shock tracer, SO, in the protoplanetary disk around HD 100546. The detected emission is spatially and spectrally offset from that expected for a purely Keplerian disk. We proposed that the SO is tracing an accretion shock from a circumplanetary disk (CPD) associated with the giant planet embedded in the gas disk at 50 au. However, due to the limited spatial resolution of the data we were unable to rule out our alternative hypothesis, that the SO is tracing a molecular disk wind. With these proposed observations we will be able to unambiguously distinguish between the two proposed processes. A successful confirmation of the presence of a CPD would be a breakthrough discovery, the first of its kind, and will confirm the diagnostic power of SO as a tracer of giant planet formation. | Disks around low-mass stars | Disks and planet formation | 2022-09-09T20:28:54.000 |
| 3732 | 2023.1.00976.S | 0 | Physical conditions in the molecular gas of a massive cold disk galaxy at z~4 | ALMA's unparalleled sensitivity and angular resolution have recently yielded the discovery of a (largely unanticipated) sample of kinematically-cold disk galaxies at z~4. Targeted using HI absorption-selection or sub-mm emission, the morphology and kinematics of these disks contrast greatly with the clumpy, irregular systems typical of high-z, UV-selected galaxies. Recent theoretical works suggest these disks arise in massive halos with gas accretion dominated by high angular momentum flows. Here, we propose to examine the nature of the star-forming regions in these first disks through analysis of the CO excitation. We will target a representative cold disk galaxy (DLA0817g1 at z=4.26) with previously detected CO(2-1) emission, and propose to use ALMA to measure the flux densities of the CO(4-3), CO(5-4), CO(6-5), and CO(7-6) lines, to determine the CO spectral line energy distribution (SLED). Analysis of the CO SLED will yield the molecular gas density and temperature to reveal the physical conditions of the molecular ISM. In turn, these offer a direct test of models describing the formation of the first disk galaxies and their role in the build-up of the more massive systems. | Damped Lyman Alpha (DLA) systems | Cosmology | 2025-01-27T18:43:20.000 |
| 3733 | 2018.1.00115.S | 230 | Anticenter Dark Neutral Matter | The methodology of using molecular absorption from species like HCO+ and C2H with stable abundance relative to H2 allows us to distinguish between atomic and molecular dark gas - the dark neutral matter (DNM) - while testing the ability of 21cm and 2.6mm emission to trace column density, and it provides independent estimates of the CO-H2 conversion factor and dust/gas ratio. Using Cycle 4 observations along 13 sightlines in Chamaeleon, we detected H2 along all 12 directions lacking detected CO emission and found a standard CO-H2 conversion factor in the other direction. We found that the DNM was largely molecular while the sampled gas overall was 2/3 atomic. Determining when DNM is HI and when it is H2 is fundamental to understanding the transition from HI to H2 and the structure and assembly process of molecular clouds. Building upon our ALMA Cycle 4 results in Chamaeleon we propose to observe 3mm absorption from HCO+ and other molecules toward a sample of 34 of the brightest ALMA phase calibrators in the Galactic anti-center, where Remy et al. (2017,2018) have performed a comprehensive analysis of the dark neutral matter while studying the underlying cloud structures. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-12-21T16:18:50.000 |
| 3734 | 2016.1.00346.S | 5 | Difference of the Abundace of Cold Atomic Carbon between T Tauri and Herbig AeBe stars | This study is the resubmission of the accepted proposal in cycle 3. We propose to observe protoplanetary disks around T Tauri and Herbig AeBe stars in the [CI] 3P1-3P0 line at 1" resolution. Atomic carbon is a unique probe for understanding disk dissipation and dust evolution in the disk, but a fine-structure line of atomic carbon at submillimeter wavelengths was not detected from a protoplanetary disk until very recently. However, we recently reported the first detection of [CI] emission from the protoplanetary disk around a T Tauri star with ASTE. The next step to be taken is a survey of a representative sample of the disks to increase the number of detection. Our targets are nine well-studied disks in nearby star forming regions. If the [CI] emission is successfully detected from these targets, we will get clues for understanding the nature of atomic carbon in protoplanetary disks. These observations will provide us new information about the physical/chemical conditions in the upper layer of the disk. Our sample covers wide ranges of spectral type and age, and thus we will be able to discuss the connection between the [CI] emitting condition and the stellar properties. | Disks around low-mass stars | Disks and planet formation | 2018-05-12T04:40:09.000 |
| 3735 | 2013.1.00328.S | 14 | A detailed view of the Bird's anatomy: the vital organs of a rare triple galaxy merger | The Bird is a luminous infrared galaxy (LIRG), logL_IR(L_sun)=11.89, product of a triple merger. The ongoing star formation (SF) in the least massive of the components (the head) outshines that of the primary nuclei (the heart and the body) as evidenced by our Spitzer-24um imaging, hence dominating the LIRG phenomenon in the Bird. This clashes with the commonly accepted major merger scenario in which the SF is expected to be higher in central compact regions. The Bird has a global high SF rate of ~190Msun/yr and shows spectroscopic evidence for outflowing gas reaching v~600 km/s. The complexity of this system makes it a perfect laboratory to study star-forming regions with a wide range of physical conditions, which we can probe with the aid of sub-mm observations. For doing this, we propose to perform a detailed study of the gas (12CO 1-0, 3-2 and 6-5, 13CO 3-2) and dust continuum of the three NIR-bright components of the Bird. The proposed ALMA observations, together with our NIR, MIR and optical data, represent a unique dataset that will allow us to test the major merger scenario, whilst making the Bird a local template to be compared to IR luminous high-z galaxy mergers. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2016-08-14T00:00:00.000 |
| 3736 | 2017.1.01107.S | 181 | The chemistry of M dwarf protoplanetary disks | M dwarfs are proposed to host the majority of habitable zone, rocky planets in the Galaxy. These planets assemble from gas and solids in disks around pre-main sequence M dwarfs. M dwarf planet compositions, including the planets' chemical favorability to life, is set by the chemical composition of such disks. The chemical content of these disks is, however, largely unknown as they have not yet been targets of millimeter chemical studies. To remedy this we propose to obtain first ALMA constraints on the chemical richness of M dwarf disks. To achieve this goal, we propose to observe five M dwarf disks in 7 molecular lines commonly used to probe T Tauri disk chemistry. The five disks have been selected from three recent surveys of Taurus, Lupus and Chameleon to have bright CO emission, enabling other molecular line detections, and stellar masses between 0.14-0.25 solar masses. The targeted molecular lines will provide constraints the importance of UV chemistry, C/O ratios, and the content of prebiotically important organics in the disks, and enable a first assessment of how the M dwarf disk chemistry compares to the chemistry in Solar nebula analogs. | Disks around low-mass stars | Disks and planet formation | 2019-10-04T19:41:57.000 |
| 3737 | 2016.1.01512.S | 26 | The Gas Mass and ISM Heating in Normal Galaxies Near the Peak of Star Formation Activity | The bulk of the star-forming galaxy population forms a tight "main sequence" in stellar mass versus star formation rate. Increasingly, observations of the H2 content of main-sequence galaxies at high-z probe smaller galaxy masses and subsolar metallicities, and already experience the problem of weak CO emission well known in local metal-poor galaxies. We propose to image at ~3 kpc resolution the [CII] and CO(3-2) lines and the dust continuum on a main-sequence galaxy at z=2. This galaxy is part of the PHIBSS CO and SINFONI samples which provide key molecular gas, resolved Ha, and metallicity information. Our main goals are: (1) obtain resolved kinematics and study disk stability; (2) probe the "CO-dark" H2 gas and investigate the CO-to-H2 conversion factor, and (3) study the photoelectric heating efficiency in a regime not explored before. | Starbursts, star formation | Active galaxies | 2018-02-11T06:57:54.000 |
| 3738 | 2024.1.00951.S | 0 | CHIMERA:CO H2 Molecular gas ExploRAtion of Leo T | We propose ALMA Cycle 11 band 3 observations to aim for the first detection of the CO(1-0) line in the dwarf galaxy Leo T. This galaxy is the closest (~410 kpc), least massive (log[Mstar/Msun]~5), gas-rich (M_HI/Mstar~2) dwarf galaxy that still presents evidence of recent star formation, interrupted ~200 Myr ago, making it an ideal laboratory to probe star formation models at the low-mass regime. The combination of H2 content estimation from ALMA observations and ancillary H-HI data will allow us to explore the evolution of the multiphase composition of the dwarf ISM, as well as the impact of environmental mechanisms (e.g. ram pressure, thermal compression, gas mixing) on the baryon cycle of dwarf galaxies that have extremely low escape velocities. Our aim is to address the following questions: What processes quench the star formation activity in dark-matter haloes with low potential wells? How accurate are simulations at predicting the multi-phase distribution of neutral/molecular gas in dwarf galaxies? How does the CO-to-H2 conversion factor behave in low metallicity environments (e.g. [Zstar/H]<-1)? | Dwarf/metal-poor galaxies | Local Universe | 3000-01-01T00:00:00.000 |
| 3739 | 2019.1.01362.S | 9 | Testing the high-z main-sequence paradigm with ALMA : from disk instability to clumps, bulge formation and quenching | Evidence has emerged that galaxy-internal processes such as disk instabilities in gas-rich star-forming galaxies play an important role in the early evolution of massive galaxies. We propose to constrain these processes with deep, spatially resolved ALMA CO and [CI] observations of BX610, a "normal" massive (~1e11 Msun) main-sequence z=2.21 disk galaxy with prominent star-forming clumps and a massive stellar bulge. We will study the cold gas distribution and kinematics for BX610, whose stellar and ionized gas structure/kinematics have been well determined from 0.2" resolution VLT and HST data. The deep CO (4-3) and [CI](1-0) observations will explore the relation between the gas mass and star formation activity on 1-kpc scales across the disk to investigate the star formation process at z~2 on clump scales. Kinematic analysis of the resolved structures will help to constrain the origin of the clumps, and test the disk instability paradigm that may explain the observed disk galaxies at high-z and the formation of bulges that could transform galaxies into quiescence. | Galaxy structure & evolution | Galaxy evolution | 2022-08-26T16:25:51.000 |
| 3740 | 2013.1.00170.S | 6 | The cool sub-millimetre chromospheres of alpha Centauri | Like the Sun, its twin alpha Cen A displays the phenomenon of temperature minimum in its FIR/submm spectral energy distribution (SED). The temperature minimum is associated with the bottom of the chromosphere beyond which temperatures rise all the way up to several million Kelvin in the corona. The processes that lead to the heating of these atmospheric layers constitute a major challenge to solar physicists. The observation with ALMA of the chromospheres of the solar-type stars alpha Cen A and B will put the solar heating problem into astrophysical context, potentially contributing to its solution. ALMA will provide the necessary sensitivity to sample their submm continua in all bands at a high rate. This will provide detailed information about the shape of the SEDs and hence provide a handle on the opacities, governing the thermal balance of their chromospheres. As these stars exhibit different levels of activity in their cycles, the simultaneous comparison addresses the open question as to whether the cause of the solar heating is to be sought over the integrated stellar disc (QS) or in active sub-arcsecond structures (AS), providing feedback between solar and stellar physics. | Main sequence stars | Stars and stellar evolution | 2016-05-22T08:15:03.000 |
| 3741 | 2017.1.00598.S | 47 | A Search for Infrared Cores in Compton Thick AGN | Recent ALMA observations have uncovered the existence of hot (T>100K), highly obscured (N_H > 2e23 cm^-2) infrared cores in galaxies, via detection of emission from vibrationally excited HCN (HCN-VIB). Though the nature of these "Compact Obscured Nuclei" (CONs) is not fully understood, they likely harbor compact starbursts and/or accreting supermassive black holes. The high column densities of these objects mean an AGN lurking in the center could be Compton thick (CT; N_H > 10^24 cm^-2), and thus difficult to identify at most wavelengths. Despite some known overlap in the CON and CT AGN populations, their connection is not fully understood. We propose HCN-VIB observations of a sample of 4 objects, selected on the basis of their CT obscuration towards the X-ray-detected AGN to determine whether these objects also contain IR cores. Detection of HCN-VIB (which is optically thin) would also enable us to probe the internal dynamics and structure of these highly obscured systems. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2019-10-01T21:29:17.000 |
| 3742 | 2016.1.01333.S | 10 | Identifying the mysterious radio source close to the optical position of the short GRB 050709 | In the current paradigm short GRBs are produced by the merger of two compact objects, two neutron stars (NSs) or a NS and a black hole, after an evolutionary phase of inspiral that can last for billions of years. However, some population synthesis models also predict merging compact objects at much younger ages which should be hosted in star-forming galaxies. If some short-GRB progenitors are members of a young stellar population, they should explode close to their natal star-forming regions. Recently, based on ATCA 5.5 GHz observations we found a radio source close to the optical position of the 10 yr-old short GRB 050709. Within the astrometric uncertainty, the position of this source coincides with the position of the GRB. The data suggest that it is a star-forming region. Here we propose to use ALMA to search for the expected counterpart of this source in band 6 and 9. If it is a star-forming region then we should detect it. If we do not detect it then there is an excess of 5.5~GHz flux, which would imply that a different radiation mechanism is at work that powers the radio source. Whatever result we get, both interpretations are exciting. | Gamma Ray Bursts (GRB) | Cosmology | 2018-03-14T18:50:54.000 |
| 3743 | 2015.1.00475.S | 2 | Investigating the water deuteration in a young protostellar system | The evolution of water from its formation in the molecular cloud until its incorporation in the protoplanetary disk and then comets and asteroids is still unclear. Measuring the water D/H ratio is particularly helpful to answer this question. We propose to carry out multi-line observations of the water isotopologues (HDO, H2-18O and D2O) at high spatial resolution (0.3 arcsec, 35 AU diameter) towards the inner regions of the well-known Class 0 protobinary IRAS16293-2422, which is now possible thanks to the enhanced capabilities of ALMA. Through the study of the kinematics and the determination of the HDO/H2O and D2O/H2O ratios with radius from the protostars, we can determine if the water present at the Class 0 stage was preserved or reprocessed until its incorporation in disks and primitive icy bodies. The data will also allow us to determine the mechanisms that control the water vapor abundance in the warm inner regions of Class 0 protostars. This proposal is a resubmission of the B-ranked Cycle 2 proposal 2013.1.00061.S. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-08-02T15:46:00.000 |
| 3744 | 2019.1.00642.S | 35 | Constraining effects of convection and pulsation: ALMA SiO and VLTI imaging of asymptotic giant branch stars | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2022-09-22T20:44:06.000 | |
| 3745 | 2021.1.01543.S | 448 | The Brightest Lensed High-z Sources from Nearly Half the Observable Universe | We seek redshift confirmation of outstanding lensed, sub-millimeter galaxy targets that we have found in an 18,000 sq. deg survey. This is a seven-fold increase in the sky area previously surveyed for such galaxies. Sub-millimeter galaxies have among the highest star formation rates in the Universe and occur at such early times that they challenge our understanding of galaxy evolution. They serve as excellent targets for JWST characterization. Probing the progenitors of massive elliptical galaxies, our investigation addresses ALMA's science driver on the origin of galaxies. Our conservative, multiband selection uses data at 150 GHz, 220 GHz and Planck 857 GHz to generate a sample of 16 bright, dusty, and likely high-redshift candidates. Our pipeline independently finds two galaxies with verified redshifts z > 4. We have cross-matched against extra-galactic catalogs to identify potential foreground lenses, and inspected optical images. ALMA provides an ideal facility to confirm the redshifts of these extreme objects: we propose spectral scans of ALMA band 3 to measure lines of CI and CO. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2023-03-11T18:57:48.000 |
| 3746 | 2019.1.00691.S | 19 | An ALMA/JCMT Study of the Time-Variable Class 0 Protostar HOPS 358 and Its (Warped?) Protostellar Disk | The JCMT Transient Survey recently discovered that the Class 0 protostar, HOPS 358, decreased in 350 GHz continuum brightness by 25% over a period of 20 months, with the change likely due to time-variable mass accretion. Based on the Herschel SED, HOPS 358 is thought to be among the youngest protostars in NGC 2068 and therefore an excellent candidate for studying the earliest stages of mass assembly. Fortuitously, the VANDAM: Orion Survey (PI: Tobin) observed HOPS 358 at 0.1" angular resolution with ALMA at 345 GHz before it began to fade, revealing a bright, resolved edge-on disk. For young protostars, the effective disk viscosity determines the mass accretion rate. Thus, measurement of the variations in the accretion rate and the corresponding appearance of the disk, including a potential disk warp seen in the VANDAM observations, will provide vital clues to how protostellar mass is assembled. HOPS 358 presents the first opportunity to directly study a Class 0 disk at various levels of protostellar activity and constrain the physical processes related to accretion. We thus propose to re-observe HOPS 358 with ALMA Band 7, while its brightness remains low. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2022-11-18T15:19:19.000 |
| 3747 | 2023.1.01090.S | 0 | A complete CO survey of all known fast radio burst host galaxies at z < 0.15 | Fast radio bursts (FRBs) are among the least understood, enigmatic transients. Because the link between progenitors and specific environments is expected, observations of host galaxies are essential to constrain progenitor models. CO observations of host galaxies provide ISM properties in the environment of FRBs. In the past six months, three papers on CO observations have been published, indicating a high interest in and importance of CO observations. These studies based on 6-7 hosts suggest diverse molecular gas properties different from local star-forming galaxies. However, the difference is not significant due to the small sample size. Here we propose to observe CO(1-0) in 6 FRB hosts, doubling the sample size. We aim to statistically verify whether molecular gas properties differ from those of local star-forming galaxies or other galaxy populations (such as the hots of GRBs and SNe). The targets are unbiasedly selected from the accurately-localized, spectroscopically-confirmed hosts, well observable with ALMA, providing the complete CO sample of known FRB hosts at z < 0.15. | Transients | Stars and stellar evolution | 2025-08-02T16:22:36.000 |
| 3748 | 2017.1.00784.S | 0 | The Molecular Gas Content in the NGC 5044 Group | The NGC 5044 group is the best candidate for studying star formation in an AGN-perturbed cooling flow due to its proximity and extensive multi-frequency coverage. Our ALMA cycle 0 observation of N5044 in CO(2-1) detected 24 molecular structures. Based on the molecular masses and CO linewidths, these structures are probably giant molecular associations and not individual GMCs. In cycle 4, we successfully proposed for higher spatial resolution observations with the primary goal of resolving these structures into individual GMCs and obtaining the first statistical sample of GMCs that condensed out of a cooling flow. While our previous ALMA observations have been very informative regarding the properties of compact molecular structures in cooling flows, the majority of the molecular gas (~70%), as measured by an IRAM 30m obervation, remains unaccounted for in the ALMA 12m array data. For this cycle, we propose a 7m array observation in CO(2-1) to probe the more extended and diffuse component of molecular gas. The distribution and kinematics of this dominant molecular component is essential for a full understanding of the formation of molecular gas in cooling flows. | Early-type galaxies, Galaxy groups and clusters | Galaxy evolution | 2020-02-05T20:54:22.000 |
| 3749 | 2021.1.00134.S | 31 | Internal structure of a proto-brown dwarf | We propose high angular resolution and high sensitivity observations with ALMA to conduct a pilot study of the internal structure of a bona fide proto-brown dwarf (proto-BD). We will observe the HCO+(3-2) and HCN(3-2) lines, which are the brightest ones detected in the proto-BD from previous IRAM 30m observations. We have derived self-consistent physical+chemical models that can reproduce the observed molecular line emission and provide a first-order approximation to the internal structure of the proto-BD. The models predict that the HCO+ and HCN species provide a contrasting view of the internal structure in a proto-BD, such that, HCN can reveal the small-scale structures in regions where HCO+ is depleted. High-sensitivity ALMA interferometric observations at a high angular resolution of ~0.5" can confirm the predictions from our physical+chemical model on how the different physical components (envelope, outflow, disk) contribute to the emergent molecular line intensity in a proto-BD. This will be a pioneering study with ALMA to understand the chemical inhomogeneities and the removal and survival of molecular species from the gas phase in different layers of a proto-BD core. | Brown dwarfs | Stars and stellar evolution | 2023-09-09T14:11:52.000 |
| 3750 | 2016.2.00139.S | 18 | Molecular Gas in the Brightest Strongly-Lensed AGN Host in the Southern Sky | Based on Herschel/SPIRE observations at 250-500 micron, we have recently identified the apparently most luminous active galactic nucleus (AGN) host galaxy in the southern sky. Magnified by a factor of 30 due to strong gravitational lensing, our target has an intrinsic star formation rate of ~250 Msun/yr, making it representative of the underlying population. We here propose to use the ACA to detect CO(3-2) emission in this unique target. This will yield the first estimate of its molecular gas mass and gas depletion timescale, allowing us to place it on the "star formation law" for AGN-starburst systems in the early universe. The precise systemic redshift, line shape, and line flux provided by this investigation are a necessary prerequisite for detailed investigations in multiple molecular tracers at high resolution with ALMA in the future. Our full study will yield significant improvements in our understanding of the evolution of massive galaxies through cosmic times. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2018-07-31T17:32:24.000 |
| 3751 | 2011.0.00397.S | 0 | The most luminous heavily obscured, radio-intermediate, QSOs and the role of radio feedback in black hole and spheroid evolution | We propose continuum snapshot observations in Band 7 (345 GHz) for 49 mid-infrared luminous, heavily obscured, QSOs from the Wide-field Infrared Survey Explorer (WISE) survey. We cross-correlated the WISE mid-infrared catalog with the NVSS radio surveys to select luminous 1 1 QSOs with buried radio jets capable of triggering accretion powered feedback in 7100 square degrees. These observations make excellent use of the early array because we can unequivocally separate AGN-dominated from starburst-dominated systems due to the brightness of our sample. We can thereby characterize them by AGN-starburst evolutionary phase and radio-loudness. The primary goal of the multi-telescope program is to understand in detail the physical and evolutionary nature of these candidate radio feedback-phase objects, which are amongst the most luminous QSOs in the universe, observed at the peak galaxy formation epoch: how do they fit onto the evolutionary sequences suggested by models such as those of Hopkins et al (2008)? Are they indeed young QSOs or are some of them older systems that are highly inclined to the line-of-sight? How is the starburst disrupted and the molecular material dispersed? What can these very rare objects tell us about the sequence of the growth of BHs and spheroids? The program lays the groundwork to prepare for more detailed mapping and kinematics of important CO and CII lines in later ALMA observing cycles, and with EVLA and possibly VLBA, after redshifts become available. Time will be also be sought with Herschel, Chandra, and HST. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2013-10-17T13:42:00.000 |
| 3752 | 2018.1.00699.S | 233 | Resolving Massive Molecular Outflows in a Representative Sample of Local ULIRGs | Galaxy formation scenarios of massive galaxies invoke regulation/quenching of star-formation (SF) due to high-velocity, massive molecular outflows to explain the high-end of the galaxy mass function. These outflows driven by coeval accreting BHs and nuclear starbursts are predicted during the IR-luminous star-forming phase of galaxies at z~1-4. The same mechanisms have been invoked to explain the evolution of low-z ultra-luminous infrared galaxies (ULIRGs), from SF-dominated to naked QSOs. Our Cycle 4 pilot program has characterized, and spatially resolved, extended (1-4 kpc) molecular outflows in 5 out of 6 nuclei in 3 close interacting ULIRGs. We propose to extend this study to a representative sample of 23 ULIRGs (19 new + 4 archive) covering the different nuclear activities, and advanced interaction phases of the ULIRG population. Similar to Cycle 4, the 500pc resolution CO(2-1) data, will provide key outflow geometrical (size, axis) and physical (mass, velocity, and time scale) properties, needed to confirm, or not, the effective removal of the raw material needed for SF and, thus, test the galaxy formation models of massive galaxies in their low-z analogs (ie. ULIRGs). | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2021-01-04T17:45:50.000 |
| 3753 | 2012.1.00129.S | 0 | GG TAU AB: Studying viscous and tidal effects in the circumbinary disk | We propose to observe the hierarchical system of GG Tau AB simultaneously in $^{12}$CO, $^{13}$CO 3-2, and 0.8mm continuum emission in Band 7 (B7), using an extended configuration (0.22") of ALMA. The unprecedented resolution in B7 will allow us to accurately probe the impact of viscous spreading and tidal disturbances on the shaping of both circumbinary and circumstellar gas and dust. Thanks to its distance ($\sim 140$~pc) and brightness (800 mJy at 1.3mm), the GG Tau AB system, two young (TTauri) binaries separated by 11'' (with stellar separations of 0.25'' and 0.4'' for A and B binaries), provides a unique opportunity to study the physics and dynamics of the mass distribution in a young multiple system. In particular, these new images will allow us 1) to precisely measure the morphology of the circumbinary ring (ring width, internal and external slopes of surface density), 2) to search for any azimuthal asymmetry or inhomogeneity in the ring, 3) to map the $^{12}$CO and $^{13}$CO 3-2 lines within the gap searching for departure of Keplerian velocity and 4) to measure the individual continuum flux densities of the inner circumstellar disks. | Disks around low-mass stars | Disks and planet formation | 2015-01-30T00:00:00.000 |
| 3754 | 2019.1.01142.S | 243 | A unique study of dust, metals, gas, and star formation in typical galaxies at z~2 | The properties of the far-IR/submm dust emission of a galaxy are determined primarily by the star-formation rate (SFR) and metallicity. The current ALMA high-redshift studies, accumulated over the first 6 cycles, have focused on massive galaxies, with only a handful of them having metallicity measurements. We will complement these studies by observing the dust continuum emission of 27 galaxies at z=2.0-2.5, spanning over a wide range of metallicities, in ALMA band 6. These galaxies are drawn from the MOSFIRE Deep Evolution Field (MOSDEF) survey. MOSDEF galaxies are characterized by several key measurements enabling this study, including precise spectroscopic redshifts, robust metallicity measurements based on multiple optical lines, accurate dust-corrected H-alpha SFRs, and pre-existing Spitzer/MIPS mid-IR data and ALMA CO(3-2) observations, enabling the estimation of the PAH emission and gas content, respectively. Combining these measurements with the proposed ALMA dust continuum observations will help us to explore the interplay between dust, metals, gas, and star formation at z~2 and provide insight into how metallicity affects the submm properties of high-redshift galaxies. | Galaxy structure & evolution | Galaxy evolution | 2023-06-24T06:33:24.000 |
| 3755 | 2022.1.01657.S | 700 | Building the first statistical sample of powerful radio galaxies within the Epoch of Reionisation | The rapid early growth of the first supermassive black holes (SMBHs) remains a major astrophysical puzzle. Powerful radio galaxies have long been beacons of active SMBHs. However, unlike luminous optical QSOs, radio-luminous active galactic nuclei are still undetected within the Epoch of Reionisation at z > 6.5. A pilot study outlined a new method for finding ultra-distant radio galaxies using low-frequency radio spectral curvature properties. From only four sources, a powerful radio galaxy was discovered at z = 5.55 via the ALMA Band-3 detection of two CO emission lines; this is the second-most distant radio galaxy currently known. A subsequent study built upon this successful pilot and presented a much larger sample of 51 new ultra-distant radio galaxy candidates selected from the MWA GLEAM survey. Follow-up deep near-infrared VLT K-band observations indicate that 14 of these 51 sources have K > 23 (AB) and hence are excellent candidates for being at very high redshift, potentially at z > 6.5. We propose ALMA Band-3 observations of these targets to determine spectroscopic redshifts, conduct broadband radio spectral modelling and characterise the molecular gas properties. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-02-08T19:47:46.000 |
| 3756 | 2016.1.00232.S | 58 | Resolving the kinematics in the torus of NGC1068 | We propose to image with ~0.03"(2pc) spatial resolution the emission of a set of molecular lines, including CO(2-1), CO(3-2) and HCO+(4-3), and their underlying continuum emission in the circumnuclear disk (CND) of NGC1068, covering a region that extends from r~100pc down to the central 7-10pc-diameter torus of this Seyfert 2 galaxy. The putative torus has been, for the first time, imaged by ALMA in the dust continuum and CO(6-5) submillimter line emission using a resolution 0.05"-0.07" (4pc) (Garcia-Burillo+16; GB16). The observations of GB16 nevertheless fell short of fully resolving the kinematics of the torus, characterized by strong non-circular motions and enhanced turbulence. The new observations proposed can fully resolve the torus kinematics using three lines spanning three orders of magnitude in densities. We will also use the CO(2-1) line to image the submillimeter counterpart of the NIR gas lanes which connect the outer regions of the CND with the torus (Mueller-Sanchez+09), and which could be the signature of inflowing gas. Furthermore, the high-resolution continuum emission in Band#7 will provide key constraints to the CLUMPY torus models explored in GB16. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-11-24T13:41:34.000 |
| 3757 | 2015.1.00932.S | 470 | Measuring the Spectral Evolution, Structure, and Speed of Extragalactic Jets with ALMA | We propose high-resolution mm imaging of 13 AGN with powerful kpc-scale jets, in order to accurately map the synchrotron emission of the jet as it extends out from the host galaxy. Chandra X-ray observations have revealed very hard X-ray spectra which has lead to the prevailing interpretation that the X-rays are due to inverse-Compton upscattering of CMB photons (IC/CMB) by a jet which is still relativistic on kpc scales. However, very recent work by our group has shown that the gamma-ray flux implied by this mechanism is not detected, implying a mysterious second synchrotron component. In order to positively rule out the IC/CMB model in a larger sample, we must acquire an accurate measurement of the synchrotron spectrum of the jet near the sub-mm peak in order to exactly predict the gamma-ray spectrum expected & interpret the existing upper limits. With the ALMA imaging we propose, we will be able to settle over a decade of ambiguity about the emission mechanism of the X-rays, and place strong limits on the their speeds on kpc scales. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-03-21T02:11:18.000 |
| 3758 | 2017.1.00687.S | 197 | From filaments to cores: Dynamics in infrared dark clouds | Massive stars shape the visible Universe, yet we do not know how they form. Currently available observations of massive star forming regions reveal a complex hierarchical structure from the global (cloud) to intermediate (fibre) to individual forming star scales (cores). However, due to the lack of observations on the intermediate-to-small scales, constraining the role of these structures in the theoretical models of massive star formation is not possible. The proposed observations of 10 quiescent infrared dark clouds will allow us to: (1) separate the complex kinematic structures spatially and spectrally, in order to search for coherent, intermediate scale structures throughout the clouds. The morphologies and properties of these structures will be compared to those of the cores, identified in continuum, and the structures identified in single dish observations. (2) Constrain the theoretical models which provide predictions regarding the role and formation of these structures. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-10-19T12:53:43.000 |
| 3759 | 2018.1.00566.S | 21 | A Magnified View of Black Hole/Galaxy Co-Evolution at the Epoch of Reionization | Gravitational lensing allows studies of distant galaxies and quasars with enhanced sensitivities and resolution beyond the limit of current instrumentation. We recently discovered an ultraluminous lensed quasar/starburst system at z=6.51, the most distant lensed quasar known and the first such object detected at the epoch of reionization. Lens models based on HST observations show that the quasar is magnified by a factor of ~25. We propose to carry out high resolution ALMA Band-6 observations of the dust continuum and [CII] emission of the quasar host galaxy. Our main science goal is to use the lensing reconstructed dust continuum image to measure the spatial distribution of star formation in the central starburst surrounding the accreting black hole (BH), reaching a resolution of <100pc, comparable to the scale of the sphere of influence for a billion M_sun BH. We will also use the reconstructed [CII] map to probe the host galaxy ISM kinematics, estimate its dynamical mass and search for signatures of a galaxy merger and AGN feedback. The proposed ALMA observation will provide a unique laboratory to study BH/galaxy co-evolution at cosmic dawn in unprecedented detail. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2022-10-20T22:30:00.000 |
| 3760 | 2016.2.00117.S | 62 | Exploring High Deuteration of Formaldehyde in the Low-mass Protostar L1527 | Despite the low elemental abundance of deuterium (D/H~1e-5), the [D2CO]/[H2CO] ratio is reported to be as high as a few tens of percent in low-mass protostars. For instance, the [D2CO]/[H2CO] ratio is found to be 0.44 in the low-mass protostar L1527. However, the mechanism responsible for such a high deuteration is still an open question. We recently analyzed the D2CO and H2CO data observed toward L1527 with ALMA, and found that the distributions of H2CO and D2CO are different. While H2CO resides in the inner sublimation region near the protostar (<200 au), D2CO mainly resides in the cold outer envelope (~500 au). This result suggests that the high [D2CO]/[H2CO] ratio originates from deuteration in a cold and dense region where CO is heavily depleted. Although this is an interesting indication, we need short baseline data recovering the extended components for a definitive conclusion. In this proposal, we therefore conduct the supplemental ACA observations of H2CO and D2CO to delineate the [D2CO]/[H2CO] ratio accurately. This observation will provide us with an important clue to solving the long-standing mystery of the high [D2CO]/[H2CO] ratio in low-mass protostellar sources. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-10-06T12:41:48.000 |
| 3761 | 2019.1.01619.S | 52 | Tracing Volatile Delivery onto Forming Giant Planets PDS 70 b and c | The atmospheric and core composition of planets are determined during their formation phase within their natal environments. The final elemental composition is set by the mass accretion process, which first leads to massive refractory cores, and then rapidly accretes gaseous atmospheres once run-away accretion occurs. We have now entered the era where the atmospheric composition of giant planets can be characterised by transmission and thermal emission spectroscopy, and at the same time information on the chemical composition of protoplanetary disks can be retrieved by spatially resolved observations thanks to ALMA. PDS 70 represents the best case to connect the two complementary information, being the only disk known to date to host multiple accreting protoplanets and circumplanetary disks. We propose to characterize the elemental composition and C/O ratio of volatile material in PDS 70. At the same time, we search for azimuthal asymmetries in brightness temperature of lines that are known to be sensitive to local temperature and UV radiation variations due to the accreting protoplanets. Finally, we search for shock signatures on the CPDs surface, expected by theoretical models. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2021-06-20T20:50:48.000 |
| 3762 | 2011.0.00742.S | 0 | ALMA Imaging of the Star Formation Process at the Historic Peak | We propose an ALMA ES "mini-survey" of z~2 sources to image the 158 µm [CII] line in four objects from three representative sources from our ZEUS/CSO survey. Through ZEUS/CSO spectroscopy we have detected the [CII] line from 22 star forming and AGN dominated galaxies in the z~1-2 redshift interval. The redshift range 1-3 is important since half the star formation through cosmic time occurred in this epoch. The [CII] line is a critical tracer of star formation, and we use this line together with the FIR continuum and CO lines to constrain the intensity and physical size of star formation regions. We find that star formation dominated sources host kpc-scale star formation regions with surface intensities similar to that of local starburst galaxies. This suggests a more quiescent mode of star formation in this epoch than the extremely intense and temporally punctuated starbursts powering similarly luminous local ULIRGs. We also find relatively weak [CII] emission in AGN dominated systems and evidence for [CII] line emission from the AGN-associated XDR in at least one system. Our ALMA ES source list samples a variety of environments capable of emitting strong [CII] line radiation that includes the blazar/AGN (PKS0215), an AGN host at the center of a proto-cluster of SMGs (RX0941) and one of the star forming SMGs within the cluster, and a transitioning starburst/QSO (SDSSJ1000). By constraining the origins and spatial distribution of the [CII] line we will trace star formation modes and efficiency. The proposed work is unique since it leverages the prior ZEUS/CSO detections of redshift 2 sources and, at ES the (Band 9) redshift 2 epoch is the only time within the historic peak of star formation in which the [CII] line can be observed. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2014-02-11T20:21:00.000 |
| 3763 | 2023.1.01128.S | 13 | High-Speed Outflows and Dusty Disks during the AGB to PN Transition | As mass-losing asymptotic giant branch (AGB) stars evolve to planetary nebulae (PNe), the mass outflow geometries transform from nearly spherical to extreme aspherical. The physical mechanisms governing this transformation are widely believed to be linked to binarity and the associated production of disks and fast jets during transitional (post-AGB) evolutionary stages. We propose a comparative study of a representative sample of bipolar & multipolar post-AGB objects chosen on the basis of evidence for fast outflows and circumstellar disks. We will map CO J=3-2 and 6-5 emission with ~0.1" resolution in order to probe the spatio-kinematic structure of the collimated outflows and the central disk/tori. 3D radiative transfer modeling will be used to derive accurate outflow momenta and masses. These results will help to distinguish between different classes of PN-shaping binary interaction models. By thus improving our understanding of the formation of aspherical PNe, our proposed study of post-AGB outflows and disks will generate new insight into a wide range of stellar mass ejection and binary interaction phenomena, ranging from novae to gravitational-wave-producing mergers. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-12-12T18:00:51.000 |
| 3764 | 2013.1.00618.S | 13 | A Survey of Very Low Luminosity Objects in Serpens and Ophiuchus | Very Low Luminosity Objects (VeLLOs) are young stellar sources that are defined by luminosities less than 0.1 solar luminosity and rising mid-infrared spectral energy distributions. But what exactly are they: brown dwarfs or low-mass stars in formation, systems exhibiting low accretion, extremely young objects? We propose to characterize the VeLLO class through observations of 1.3mm continuum and CO J=2-1 outflow emission of a sample of 12 high-probability candidates in the Serpens and Ophiuchus molecular clouds. This survey is expected to double the number of confirmed VeLLOs, provide estimates on the masses of their inner envelopes, and help address questions concerning the nature of VeLLOs. | Low-mass star formation | ISM and star formation | 2016-05-12T19:40:12.000 |
| 3765 | 2013.1.01365.S | 0 | Investigating the origin of the IMF and constraining SFR models in the W43-MM1 mini-starbust ridge | Studying extreme protoclusters is necessary to test if the IMF origin and SFE can be independent of cloud local characteristics. The W43-MM1 ridge, being extreme in terms of cloud concentration and star formation activity, is a case-study to confront star formation models. It consist of a very dense and cold mass reservoir of 20 000 Msun. We discovered that it hosts a cluster of 11 massive dense cores. With untested assumptions regarding the fragmentation of massive dense cores into protostars and the shape of the stellar IMF, we expect more than 2000 stars to form, with a SFR of 6000 Msun/Myr reminiscent of starburst galaxies. A preliminary study of the mass distribution in the W43-MM1 mini-starburst ridge suggests that statistical SFR models do not apply to ridge clouds. We propose to investigate the fragmentation of W43-MM1, down to the now well-defined protostellar size of 2000 AU. We especially want to 1) look for protostars and prestellar cores able to form early O-type stars, 2) define the size/density inside/above which the core mass function does not mimic the IMF anymore, and 3) accurately measure the SFE correlation to the cloud density and turbulence level. | High-mass star formation, Low-mass star formation | ISM and star formation | 2016-08-04T00:00:00.000 |
| 3766 | 2017.1.01425.S | 59 | Probing the magneto-ionic medium at the jet base in AGN through Faraday rotation | We apply for 12 hr of ALMA time in the full polarization mode to study the jet magnetization and particle composition in the innermost part of the jets of three AGN at 1 and 2mm. Our band 6 pilot study of 3C273 in Cycle 4 has demonstrated that AGN can exhibit extremely high rotation measures (RM) of > 10^5 rad/m^2 at short mm-wavelengths, which has opened up a new window for studying the magneto-ionic medium in and around the jet base. This gives us an unprecedented opportunity to probe the magnetic fields in the region where the jet first becomes visible and helps us to constrain the jet magnetization. Here we propose to extend the pilot study and look for more cases of high RM in AGN at mm-wavelengths. If such high RM signals are found, we will model the Faraday rotation and frequency-dependent polarization behaviour to distinguish between Faraday rotation happening inside or outside of the emission region. Our numerical simulations show that if the jets are highly magnetized, the RM in the boundary layer of the jet will dominate over the RM within the jet, which allows us to probe the jet magnetization through the RM observations. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-09-14T18:17:38.000 |
| 3767 | 2013.1.01161.S | 14 | From Bars to CMZs and YMCs | We propose subarcsec-resolution wide-field imaging of the entire stellar bars in two prototypical barred spiral galaxies. Our main goals are (1) the gas dynamics in bars to channel molecular gas to the central molecular zones (CMZs), and (2) ISM reactions to the bar-driven gas dynamics in the bars and in the star-forming CMZs including cloud formation leading to the formation of young massive clusters (YMCs). Our targets, M83 and NGC 1365, have face-on stellar bars of large ~4 arcmin extent on the southern sky. They will be fully mapped in CO(2-1) at linear resolutions of 10 and 50 pc, respectively, without missing any extended emission. Their CMZs will be imaged at twice higher resolutions through additional targeted observations. This project is going to reveal unprecedented details of the molecular gas behavior in galactic bars of moderate and large lengths (~5 and 20 kpc, respectively) and uncover the relation between gas dynamics, molecular cloud properties, and star cluster formation. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2016-07-31T04:51:41.000 |
| 3768 | 2018.1.01447.S | 15 | The lensed quasar SDSSJ0924+0219: a unique flux anomaly | Quasars lensed by foreground galaxies are important because they allow us to measure microlensing effects caused by stars in the lens galaxy, and millilensing effects caused by 10^6 - 10^7 M(sun) CDM structures in the lens. Both effects cause flux anomalies, ratios of the lensed quasar images which cannot be explained by smooth lens models. SDSS~J0924+0219, in the optical, has one of the most drastic flux anomalies known in a lensed quasar, previously ascribed to microlensing: however, the anomaly's persistence suggests that it may be due to CDM substructures in the lens. To definitively test this, we require observations at a wavelength where the background source is large enough to be immune from microlensing: ambiguity in cm-radio means that ALMA is the unique instrument which can do this, in a very small investment of time. | Gravitational lenses | Cosmology | 2020-01-22T19:48:19.000 |
| 3769 | 2015.1.01596.S | 2 | Disks around O-type stars: the W51 complex | There has not been a clear detection of a (Keplerian) disk around an O-type forming star so far, which led to suggest different accretion mechanisms for the most massive stars. We propose to use ALMA to map hot molecular gas towards two well-known high-mass accretion disk candidates in the W51 complex. Previous interferometric observations revealed ordered structures of accretion on scales 1000-10000 AU, but poor angular resolution and high opacity of the targeted molecular lines prevented to penetrate the innermost regions (<2000 AU) where Keplerian rotation is expected. ALMA in cycle III can now provide three key elements to overcome previous limitations: the resolution to resolve the innermost 1000 AU from the central YSOs (at 5 kpc), the correlator flexibility to tune several transitions (at different excitation) from the same molecule, and the sensitivity to detect optically-thin, weak emission from its isotopologues. This combination will allow us to probe the kinematics and physical conditions of hot gas as a function of radius (200-2000 AU) from an O-type YSO and to address the following key question: Are there Keplerian disks around O-type young stars? | High-mass star formation | ISM and star formation | 2017-01-27T01:27:43.000 |
| 3770 | 2015.1.01140.S | 14 | Do galaxies lose molecular gas more than expected? | Starburst galaxies losing material through outflows plays an important role on starburst activities. Although ionized outflows have been observed in many starburst galaxies, molecular outflows are seldom detected in the past. It is even rare to have directly imaging on molecular outflows from galaxies due to poor instrument sensitivity. However, the directly imaging could provides an accurate measurement on gas mass lose, and could show us the morphology and distribution of gas. So far there are only a few starburst galaxies with directly imaging. In this proposal we are going to observe the edge-on starburst galaxy NGC 3628, which has been directly imaged by our Nobeyama Millimeter Array (NMA) observations. Our NMA observations have detected a 500pc scale molecular outflow in the north of the galactic disk. However, the morphology and the scale do not match with its ionized outflows, which has 7-10 kpc scale bipolar outflows. If ALMA could detect molecular emission in such a large area, then NGC 3628 is losing molecular gas more than the current measurement. This also implies that galaxies evolve faster than our current understanding. | Starbursts, star formation | Active galaxies | 2017-05-11T00:00:00.000 |
| 3771 | 2022.1.00021.S | 65 | A close up view of the most recent common envelope systems | Common Envelope Evolution (CEE) is currently one of the most active research fields in the study of stellar evolution due to its applicability in a wide range of astrophysical phenomena. Great efforts have been dedicated to develop sophisticated models and numerical simulations to study the evolution of binary systems undergoing CEE. However, the observations are lagging behind theory due to the difficulty in observing the common envelope (CE) phase because of its short timescale. Recently, a group of post Asymptotic Giant Branch objects known as water fountains (WFs) were identified as systems just undergoing CEE. Two of these objects have been observed at high angular resolution with ALMA and they have already served as input for theoretical models and numerical simulations. The observations of these objects have proven to hold an enormous potential to understand CEE. Here we proposed to observed nine more WFs to clearly identify and characterise their dynamical components, such as collimated jets, equatorial torii, hourglass shaped outflows, etc. Together with state-of-the-art numerical simulations, this will allows us to study CEE with unprecedented detail. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2024-09-05T00:06:02.000 |
| 3772 | 2019.1.01532.S | 21 | 3D Structure of the Quiet Solar Chromosphere | The chromosphere, even the quiet one, is still not fully understood. Observations at mm wavelengths provide a unique chromospheric diagnostic. We propose to carry out center-to-limb observations at three frequencies (Bands 3, 6, and 7) and perform detailed tests of 3D models of the quiet chromosphere. Our observations will shed light on the thermal structure of the quiet chromosphere by comparing them with state-of-the-art radiative MHD simulations and simultaneous imaging and spectral observations in optical, UV, EUV, and X-rays. Emphasis will be given in the comparison of the measured ratio of network to cell intensity with that predicted by the models. Such comparison is very important for establishing a comprehensive physical picture of the chromosphere and cannot be done with previous and present low resolution full-disk mm wavelength data. We will assess whether the models can reproduce the mm-wavelength observations and in case of discrepancies we will investigate their origin and how the models could be adjusted. The comparison of observations and models will also help us clarify the role of spicules in the limb brightening. | The Sun | Sun | 2022-01-25T15:15:00.000 |
| 3773 | 2019.A.00028.S | 265 | The fall and rise of Betelgeuse: diving in its ejecta with ACA | Some weeks ago the recent dimming of the nearby RSG Betelgeuse caused a cascade of public news, following the suggestion by some that core-collapse may be imminent. Another hypothesis is that the visual dimming is caused by an increased extinction along the line of sight due to an enhanced dust mass-loss episode, consistent with the erratic stellar activity of evolved massive stars. We propose a monitoring programme with ACA in Bands 3 and 6 with a cadence of 15 days, to establish whether the recent visual variability is due to dust and to perform an unprecedented study of the dust properties and formation cycle. We request calibration-limited observations (with photometric uncertainty of 5%) to derive: 1) light curves for each sideband, to analyse and compare their periods and any possible phase lag due to dust life cycle; 2) internal spectral index per band, to study changes of dust opacity. We also request one epoch in Band 7 to evaluate the contribution of molecular line emission on complementary JCMT/SCUBA2 monitoring observations that were recently started. With these observations we will gain an unique insight into dust processes and mass-loss in massive stars. | Hypergiants | Stars and stellar evolution | 2022-01-01T09:35:18.000 |
| 3774 | 2017.1.00793.S | 128 | Are Magnetic Fields Dynamically Important in Massive Star Formation ? | The role of magnetic fields in molecular clouds and star formation has been debated for decades. This ALMA proposal aims at assessing the dynamical role of magnetic fields in massive star and cluster formation by analysing magnetic field morphology. We build this project on a successful SMA legacy survey in polarization of more than 14 massive star forming clumps. This unprecedentedly large sample of massive clumps observed by a sub-millimeter interferometer in a pre-ALMA era revealed on a statistical basis that magnetic fields are dynamically important in channeling the collapse of pc-scale clumps and in the formation of 0.1pc-scale cores. It also suggests that between 0.1 pc and 100 au disk-scale, magnetic fields are weakening and become less important than gravity. This follow-up proposal will quantify the role of magnetic fields relative to gravity and turbulence at the envelope scale of ~ 5000 au. | High-mass star formation | ISM and star formation | 2020-10-04T23:48:26.000 |
| 3775 | 2023.1.01453.S | 0 | A Pathfinder for a High-Precision Galactic Isotope Survey with ALMA | Stable isotope ratios like 12C/13C, 14N/15N, and 16O/17O/18O are unique fingerprints for tracing the evolution of matter in the solar system, in our galaxy, and even beyond. However, significant discrepancies between the isotopic ratios of the local interstellar medium inferred from previous measurements of the galactic isotopic composition, and the values of the Sun make it hard to decide what to use as "unfractionated" baseline value. The lack of a reliable reference value hampers the efforts to explain the large isotopic heterogeneities in cabon, nitrogen, and oxygen among the solar system bodies. All previous measurements of the galactic isotopic gradients were carried out with single-dish telescopes and have fairly large error bars. We propose to carry out a pathfinder project on a small sample of sources at different galactocentric radii to enable a future new, high-precision galactic isotopic composition measurement with ALMA. | High-mass star formation, Astrochemistry | ISM and star formation | 2025-03-27T08:54:34.000 |
| 3776 | 2017.1.00655.S | 6 | Using magnetic fields to probe the core-fragmentation model of binary formation | BHR 71 is a nearby (d ~ 200 pc) wide binary separated by ~3,400AU; the two very young, deeply embedded components are both in the earliest (Class 0) phase of protostellar evolution. The extreme youth of BHR 71 makes it unlikely that it has undergone significant dynamical evolution, making it an ideal object to study the initial conditions of binary fragmentation. Here we propose to follow up on successful ALMA observations (project 2013.1.00518.S; PI: J. J. Tobin, a co-I on this proposal) by adding one crucial element that is known to play an important role in the physics of fragmentation during star formation: the magnetic field. Based on comparisons with previous CARMA and SMA observations, we predict that BHR 71 will exhibit a strong, hourglass-shaped magnetic field, making it an ideal southern-hemisphere laboratory for testing the role of the magnetic field in the earliest stages of the protostellar fragmentation process. | Low-mass star formation | ISM and star formation | 2019-06-08T13:31:23.000 |
| 3777 | 2023.1.00184.S | 0 | Exploring the Internal Dynamics of Low-Metallicity Hot Cores in the Small Magellanic Cloud | Although massive stars play essential roles throughout cosmic history, the formation of massive stars is still poorly understood, particularly in the low-metallicity regime like the earlier epoch of the Universe. Massive protostars in the Small Magellanic Cloud (SMC) are the best targets to investigate massive star formation in the low-metallicity environment. We propose high-resolution observations of two SMC massive protostars with a resolution of 0.08", i.e., 5000au. This is the first-ever SMC project to resolve the dynamics smaller than the protostellar-core scale of 0.1pc. We will investigate the characteristics of core fragmentation by the 870um continuum, and study the dynamics of the envelopes (infalling flow and disk rotation) with the hot-core molecular lines (SO, SO2, CH3OH) and the outflows with CO and SiO. By comparing these results with the corresponding observations in the Galactic disk and the Large Magellanic Cloud, we will examine the universality of massive star formation in different metallicity environments. | High-mass star formation | ISM and star formation | 2025-09-09T14:25:41.000 |
| 3778 | 2022.A.00001.S | 4 | Stereoscopic views of the Sun with ALMA and Solar Orbiter | The upcoming perihelion encounter of the ESA/NASA Solar Orbiter spacecraft in October and November 2022, while ALMA is in a configuration suitable for solar observations, presents a rare and exciting opportunity to combine these two novel views of the Sun in powerful ways (and the only possibility until 2024). Not only will the relative position of Solar Orbiter with respect to Earth will allow stereoscopic studies of atmospheric features, but some of its instruments (PHI, SPICE) are particularly suited to address outstanding problems of chromospheric structure and heating, for which ALMA observations can provide crucial constraints. We propose a joint study between ALMA and Solar Orbiter with the goal of obtaining coordinated observations from different viewing angles to better understand chromospheric heating. We will combine data from ALMA, PHI, SPICE, and SDO to derive information on the 3-D structure of active regions. This will allow us to better localize the sites of chromospheric heating seen by ALMA and correlate them with the topology of the magnetic field. These coordinated observations will result in a unique, legacy dataset, valuable for a variety of future studies. | The Sun | Sun | 2023-10-21T21:00:05.000 |
| 3779 | 2017.1.00841.V | 0 | Imaging the Black Hole Shadow and Jet Launching Region of M87 | The supermassive black hole at the heart of the Virgo A galaxy (M87) powers one of the most well-studied relativistic jets in the sky. Due to its high mass and close proximity, it presents us with the opportunity to resolve the shadow cast by the black hole event horizon, and to image with unprecedented detail the jet launching mechanism. We propose 3 tracks of Band 6 VLBI observations with the EHT+ALMA VLBI array, which now has the angular resolution and sensitivity to detect the shadow feature, the strongest signature for the existence of supermassive black holes, and enable new tests of strong-field GR. Through full polarimetric imaging, the relativistic jet and black hole magnetosphere can be mapped, testing models of jet launch from spinning black holes at the event horizon. The observations will be accompanied by complementary (requested) 3mm observations with the GMVA+ALMA and 13mm (granted) space-VLBI observations with RadioAstron, together with a multi-band campaign including X- and gamma rays up to the TeV regime. In sum, we aim to connect the smallest objects predicted by Einstein's GR to galactic scale outflows that impact large scale structure in the Universe. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2021-05-14T01:47:32.000 |
| 3780 | 2019.A.00008.S | 46 | First D/H ratio for an interstellar comet: A window into the chemical complexity of protoplanetary system | The recent discovery of the interstellar comet 2I/Borisov provides a unique opportunity to study the chemical make-up of an extrasolar planetary system. Comets record the chemical and physical conditions in the protoplanetary disk and provide an important link in the chemical trail from molecular cloud down to the planet system. We propose to determine the D/H ratio of water in 2I/Borisov with ALMA. The deuterium fractionation is highly sensitive to the physical and chemical conditions during the synthesis of the molecules and can thus hold information on the environment, i.e., the temperature and density, in the host system during the formation of the comet. The D/H ratio of water is particularly useful for deciphering the origin of Earth's water and is among the most studied features of Solar System comets and therefore an obvious tool for comparison between the interstellar messager and our own system. Characterization of the water D/H ratio will reveal whether the birth system of 2I/Borisov had a similar chemical evolution as the Solar System. | Disks around low-mass stars, Solar system - Comets | Disks and planet formation | 2020-09-12T19:45:26.000 |
| 3781 | 2016.1.00023.S | 25 | In search of the high HCN/HCO+ ratio origin in AGNs: SiO imagings of Seyfert galaxies down to 15-30 pc scales | The origin of HCN enhancement in AGNs, which can be seen in high HCN/HCO+ ratio, is still far from well understood. Now ALMA reveals much higher HCN/HCO+ ratios found in the circumnuclear disks (CNDs) rather than the exact AGN positions, which raises a scenario that HCN is enhanced by mechanical heating such as shock of jet/outflow from AGNs (MH scenario). The immediate objective is thus to verify the MH scenario by revealing the distribution of shocked gas at high spatial resolution down to sub-CND scale. Here we propose unprecedented 15-30 pc resolution imagings of SiO J=6-5 line, a good shock tracer, toward the two distinct CNDs of nearby Seyfert galaxy NGC 1068 and NGC 1097. We aim to achieve the following science goals, which will be observational evidence to verify the MH scenario: 1. Do SiO and HCN arise from the same regions in the CNDs? --- We will confirm whether the distribution of SiO and HCN have spatial correlation or not, regardless of AGN activities of these galaxies. 2. If so, are SiO and HCN really enhanced? --- We will then compare SiO/H13CO+ and H13CN/H13CO+ ratios to confirm whether these are enhanced at the same region found the above science goal. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-04-18T16:04:09.000 |
| 3782 | 2017.1.01085.S | 193 | The Excitation of Dense Molecular Gas Tracers in Local Infrared Luminous Starbursts | The excitation mechanism of dense gas tracers such as HCN remains an open question in starburst galaxies. Enhanced HCN (relative to CO or HCO+) is often taken as a signpost of active galactic nuclei, but recent results have shown it can also be enhanced in starbursts. Does this enhancement have its origin in hot, compact, mid-IR obscured cores? We propose a systematic search for these extreme cores in a sample of nearby luminous infrared galaxies which show a range of global HCN/HCO+ ratios and appear to be starburst dominated, based on their mid-infrared diagnostics. These data will be used to constrain excitation of HCN and HCO+, including a search for evidence of IR pumping, via observations of the ro-vibrational HCN (4-3) v=1 line. Additionally, we will simultaneously observe the HCN (4-3) v=0 and HCO+ (4-3) lines to map the spatial distribution of the HCN/HCO+ ratio and constrain the physical conditions of the dense gas, providing essential information on the excitation of these molecules in extreme starbursts. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2019-09-17T19:08:56.000 |
| 3783 | 2018.1.01767.S | 178 | Quasar Feedback Survey: establishing the impact of radio jets on typical AGN hosts via sub-kpc molecular gas imaging | We are performing a systematic study of the causes and effects of feedback in a representative sample of z<0.2 AGN. We request Band 7 ALMA observations of redshifted CO(3-2) in a carefully-selected subset of our targets, which have the best combination of radio, IFS and far-IR imaging. Our primary objectives are to compare the morphologies and kinematics of the molecular gas in these systems with those seen in radio and ionized gas, and measure the energetics of molecular outflows. These sources were selected to have moderate radio luminosities (log(Lradio) < 24), yet surprisingly, all show signs of radio jets/bubbles resembling those seen in much more extreme systems. The luminosities of our targets are representative of the sources which dominate the AGN population at z=1-2, yet their relative proximity allows sub-kpc imaging with interferometers in "standard" observing modes. These observations will allow us to improve upon the current order-of-magnitude uncertainties on the energetics and impact (e.g. enhancement/quenching of star-formation) of radio jets in AGN in this luminosity range, providing crucial new constraints on theoretical models of AGN/galaxy co-evolution. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2020-06-28T11:53:11.000 |
| 3784 | 2013.1.00060.S | 11 | Physical and Chemical Properties of Giant Molecular Clouds in the Starburst Ring of NGC 1068 | We propose the band 3 observations toward the central ~1' diameter region of NGC1068 with high spatial and velocity resolution (1.1"=80pc and 1.3 km/s) in the 13CO(1-0), C18O(1-0), CS(2-1) and CH3OH(2-1). Using ALMA CYCLE 0 DATA for the central ~1' region of NGC 1068, systematic spatial variations of the CS/13CO and CH3OH/13CO are found at the GMA-scale (~ a few 100 pc), alhtough the observed C18O/13CO are found to be fairly uniform. We find that CH3OH/13CO is decreased in the bar-end regions where active star formation occurs, suggesting that the production of CH3OH is suppressed there due to high dust temperature (>20K). Clearly, the next step is to study the chemical and physical properties of ISM in the GMC-scale (<100 pc) and their relation to the global scale (> kpc) structures in galaxies. The primary goal of the proposed study is to identify GMC-scale clouds in optically-thin tracers and study a GMC-scale variation of chemical and physical properties across the disk region. We will verify our scenario on the CH3OH/13CO ratio variations in GMC scales. | Starbursts, star formation | Active galaxies | 2016-04-01T17:32:54.000 |
| 3785 | 2019.1.01778.S | 20 | The first measurement of metallicity and ISM conditions of a normal galaxy at reionisation | We can use the lensed galaxy A1689-zD1 to measure the electron density, ionisation parameter, and metallicity of a normal galaxy at z>7. Our current measurements of dust continuum, [CII]158µm, and [OIII]88µm are very high SNR and good spatial resolution and show the galaxy is composed of at least 5 distinct components with no defined overall rotation, indicating a possible multiple merger. We will measure [OIII]52µm and [NII]122µm in bands 9 and 7. We plan to go deep enough to measure metallicity down to 0.3 times solar, which is the lowest value consistent with the dust mass detected in the galaxy. Spatially-resolved measurements will also allow us to probe the chemical homogeneity and differing physical conditions of each of the components. These will be the first gas-phase metallicity measurements in a normal galaxy at this epoch apart from GRB hosts. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2021-06-26T11:03:13.000 |
| 3786 | 2021.1.01070.S | 10 | Mapping the Host Galaxy Dynamics of a Possible GW Recoiling AGN | A peculiar AGN, 2MASX J00423991+3017515, has been identified that may be an example of an AGN that is recoiling from the asymmetric emission of gravitational waves following the merger of two progenitor supermassive black holes. The broad Balmer emission lines in its optical spectrum show a kinematic offset of ~1540 km/s from their respective narrow line emission, and the AGN itself appears spatially offset by 3.8 kpc from the center of its host galaxy. Despite presenting a comprehensive multiband spectroscopic and imaging analysis, the discovery paper (Hogg et al. 2021) could not conclusively determine the object's nature because one critical diagnostic was missing: a spatially resolved measurement of the host galaxy dynamics. We propose 1" angular resolution and ~10 km/s spectral resolution observations of the CO (1-0) line to map the kinematics of 2MASX J00423991+3017515's kpc scale molecular gas. The primary goal is to determine the dynamical ``center" of the galaxy and if the AGN is appreciably displaced from it. If so, it will bolster case that this object is a bona fide GW recoiling AGN and provide a new, indirect constraint on SMBH spin evolution and merger rates. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2023-10-04T18:49:18.000 |
| 3787 | 2018.1.01230.S | 12 | Completing high-resolution imaging of the multi-ringed transition disk around GM Aur | Dust cavities in transition disks have long been proposed as signatures of forming planets, but discoveries of additional substructure in disks raise the question of whether transition disks represent a distinct evolutionary stage, or whether their cavities are sculpted by similar processes as the other substructures. In Cycle 5, we obtained high angular resolution observations of the transition disk around GM Aurigae in Bands 4 and 6. We resolve a multi-ring structure and measure a spectral index profile that has local minima coinciding with the wall of the cavity as well as an outer emission ring. Such behavior suggests that the rings arise from the trapping of large grains, or that the rings are optically thick. To distinguish between these possibilities, we will perform radiative transfer modeling of the continuum observations to infer the thermal structure and dust distribution. Because this analysis requires high-fidelity measurements of the surface brightness, we are resubmitting our Cycle 5 program to complete the requested short baseline observations in order to recover the larger-scale disk emission. | Disks around low-mass stars | Disks and planet formation | 2019-12-27T21:52:44.000 |
| 3788 | 2015.1.00032.S | 11 | The Origin of Debris Rings: Planets or Gas? | Imaged in scattered light, the bright dust rings around the 10Myr old stars HD 181327 and HR 4796A appear unusually narrow, with steep radial brightness profiles compared to other disks and theoretical expectations. The origin of these rings is unknown; they may be true debris disks where dust is created in collisions between large planetesimals, but may be a product of dust-gas interaction. Both disks also show departures from symmetry that may indicate the dynamical influence of planets, but could alternatively arise from dust-gas interaction. These scenarios have observable differences, which can only be tested with ALMA. We propose to use ALMA for 2.9h to image these two sub-mm bright rings to i) compare their radial extent to the scattered light emission to distinguish between collisional debris and gas-driven ring scenarios, ii) conclude whether the rings are truncated by planets, iii) use observed asymmetries to draw conclusions about the possible dynamical influence of planets, and iv) detect CO gas that may point to a gas-driven scenario. These results will shed light on the status of planet formation at 10Myr, shortly after dispersal of the gaseous protoplanetary disk. | Debris disks, Exo-planets | Disks and planet formation | 2017-10-06T20:40:50.000 |
| 3789 | 2024.1.01537.S | 0 | An ACA Survey of Molecular Gas in Mergers and Dual AGN | Major galaxy mergers are thought to play an important role in fueling supermassive black hole (SMBH) growth. However, observational support for this hypothesis is mixed, with some studies showing a clear link between merging galaxies and luminous quasars and others showing no such association. Galaxy merger simulations and observations suggest dual AGN activity (Koss+12) and obscuration peak when the two galactic nuclei are close to each other. We propose a survey of all 20 nearby (z<0.05) hard X-ray selected AGN from Swift BAT in mergers (4-28 kpc) that can be resolved within a single 7m ACA observation at 230 Ghz (10-25" separation) and 100 Ghz (>25") to 1): study the role of molecular gas in AGN activation in mergers and 2) use continuum observations to search for highly obscured primary AGN and undiscovered obscured secondary AGN. These observations will perform the first large ACA study of AGN in mergers, quadrupling the number of dual AGN studied at wider separations (>5 kpc) and providing a critical comparison sample of single AGN in mergers. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 3000-01-01T00:00:00.000 |
| 3790 | 2016.1.01553.S | 45 | A Critical Comparison of Different Methods to Measure SMBH Masses | With the unprecedented spatial resolution and sensitivity of ALMA, the newly-proposed molecular gas kinematics method holds great potential to accurately measure supermassive black hole (SMBH) masses in galaxies of all types. However, degeneracies between modelling parameters limits the current measurement uncertainties, and different measuring techniques have rarely been cross-calibrated. Here, we thus propose to cross-check the molecular gas method with that of megamaser disks, that currently provides the most accurate extragalactic SMBH masses. CO (2-1) emission will therefore be observed to verify the existence of molecular gas in the nucleus of maser galaxies. If strong emission is detected, higher resolution ALMA observations will complete the SMBH mass measurement in the future, enabling the first independent check of the method. Data from this proposal also enable to study the process of angular momentum transfer across different spatial scales (from the molecular gas disk to the accretion disk), and thus of SMBH feeding mechanisms, both highly contentious issues. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-05-20T12:48:42.000 |
| 3791 | 2018.1.01679.S | 31 | Direct imaging of an accretion disk arounf the youngest O star precursor | The immediate vicinity of the youngest high-mass protostars is a highly unexplored territory. In our Cycle 2 project, SPARKS, we discovered the youngest high-mass protostars with envelope masses up to 130 Msol. They are prior to the onset of strong ionising radiation. A detailed case study of one of our targets at 0.2" resolution reveals the structure of the inner envelope in an unprecedented detail. We find a compact dust continuum source of 250 au likely corresponding to an accretion disk consistent with the velocity pattern of a first vibrationally excited state HC3N line. Here we aim to use sensitive, high angular resolution observations in band 3 and band 7 to image and resolve the structure of the disk in continuum. The band 3 observations are essential because the dust is expected to be optically thin. On the other hand, band 7 provides the best candidate tracer for the gas component of the disk, which is essential to provide an independent evidence for the accretion disk revealing gas in Keplerian motion. This project would directly prove the presence of an accretion disk around the youngest high-mass protostar, and thereby strongly constrain collapse models. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2021-01-25T19:07:27.000 |
| 3792 | 2012.1.00034.S | 8 | The role of infrared radiative pumping for molecular gas excitation in AGNs | We propose HCN and HCO+ simultaneous observations at vibrationally-excited and -ground levels, of carefully-selected nearby type-1 unobcured AGNs, with non-detectable nuclear starbursts and small molecular line widths. Our first immediate objective is to provide definitive evidence that HCN emission is indeed enhanced in AGNs, compared to starburst galaxies, as suggested from our pre-ALMA interferometric observations. Our second objective is to clarify whether vibrational-excitation by infrared radiative pumping mechanism ubiquitously works for HCN in AGNs. If the ubiquity is confirmed, we will quantitatively estimate how the infrared radiative pumping enhances HCN emission in AGNs, relative to the widely-assumed collisional excitation, and obtain a physical explanation for different molecular line flux ratios between AGNs and starbursts. ALMA's high-spatial-resolution (<0.6") is crucial to probe only AGN-affected molecular gas emission at galaxy nuclei, with minimum contamination from spatially-extended star-forming activity in host galaxies. Our ultimate scientific goal is to (1) establish a physically-understood reliable tool to separate AGNs from starbursts using bright (sub)millimeter molecular emission lines, (2) apply it to distant dust/gas-rich galaxies at z=1-2 which are dominating the cosmic infrared background emission, and (3) unravel the history of star-formation and supermassive blackhole mass growth in the early universe, with ALMA in the near future. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2016-04-28T15:55:18.000 |
| 3793 | 2016.1.01304.T | 17 | The Effects of Burst Accretion on Physical and Chemical Properties of Protoplanetary Disks | FU Orinois Objects (FUors) represent the burst phase of the episodic accretion process through protostellar disks, which is considered as the formation mechanism of low mass stars. Therefore, FUors provide an opportunity to study the dynamical evolution of disk structure during outburst. In addition, newly bursting FUors are excellent targets for the study of fresh sublimates, offering a unique and direct probe of the ice composition in the pre-burst (i.e. quiescent) phase. Therefore, in order to study the burst-accretion process and the effect of enhanced heating on disk composition and structure, we propose a ToO observation for a FUor newly confirmed by one of a variety of transient surveys such as Palomar Transient Factory, ASAS-SN, and our JCMT/SCUBA2 survey for sub-mm variability. (The co-Is, Gregory Herczeg and Doug Johnstone are leading the JCMT large program on transient YSOs.) Our proposed observations include lines of CH3OH, C17O, H13CO+, HDCO, CCH, SiO, and various organic molecules at band 7 with a velocity resolution of 0.2 km/s and a spatial resolution of ~0.15". | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-05-31T01:05:11.000 |
| 3794 | 2019.1.01524.S | 26 | Using [OIII] to reveal the ISM conditions of UV-selected galaxies in the Epoch of Reionization | We propose Band 8 observations to measure [OIII]88mum in three z=6.8-7.1 UV-selected galaxies, recently spectroscopically confirmed with robust detections of [CII] from ALMA. New observations of [OIII] and [CII] show significant differences in morphology between these two line tracers. While [CII] appears more diffuse and offset from the UV light, [OIII] is compact and well-aligned with the UV-bright star-formation, suggesting very high volume filling factors of highly ionised gas in star-forming regions with high UV-surface brightness. Here, we propose to expand the sample of such measurements by targeting three new, bright and extended [CII] emitters found in Cycle 6, doubling the number of bright [CII]+[OIII] detections at z~7. The proposed observations of [OIII] will put constraints on the hardness of the radiation field and the filling factor of the warm ionized diffuse medium in the galaxies, using the [OIII]/[CII] line luminosity ratio. We will test if high [OIII]/[CII] ratios are present in the star-forming regions of these Reionzation Epoch galaxies similar to local dwarf galaxies, and require `leaking' ionizing photons from HII regions out into the surrounding ISM. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-04-26T16:42:02.000 |
| 3795 | 2022.1.01503.S | 540 | The first redshift survey of star-forming protocluster candidates identified by Planck | Galaxy clusters are fundamental building blocks of the large-scale structure of the Universe, and as such are well studied below redshifts of 1. However, at earlier times they become much more difficult to detect as standard tracers like X-rays and the Sunyaev-Zeldovich are not produced, so little is known about how galaxies in these protocluster environments evolved and interacted with their surroundings. Using maps of the submillimetre sky taken by Planck, 2151 high-z objects were identified, and subsequent follow-up has established these as excellent z~2 protocluster candidates. In this proposal we aim to determine spectroscopic redshifts for a complete subsample of four of the most overdense protocluster candidates. This is the first proposal to follow-up a statistically significant and uniformly selected subsample of Planck protocluster candidates, and our observations will allow us to place these objects within the general framework of cluster growth at a poorly-understood cosmic epoch. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2024-01-26T18:46:30.000 |
| 3796 | 2011.0.00733.S | 0 | Towards a global understanding of circumstellar disk evolution | In recent years it has been established that the evolution of circumstellar disks is fundamentally driven by the following processes: viscous accretion, grain growth, planet formation, and photoevaporation. Despite this progress, we are still far from developing a comprehensive disk evolution theory and additional observational constraints are highly required. Transition disk objects are crucial in this context as they show clear signs of disk evolution: inner opacity holes. We have performed a detailed follow-up project of Spitzer-selected transition disk systems with the aim to distinguish between different types of transition disks (Cieza et al. 2010, Romero et al. 2011). Here we propose to observe 26 transition disks characterized by Romero et al. (2011) with ALMA's unprecedented sensitivity to address fundamental issues related to grain growth, planet formation, and photoveporation in circumstellar disks. In a complementary proposal we request identical ALMA observations for 26 Ophiuchus targets (PI: Cieza). Characterizing a large and homogenous sample of transition disks from star forming regions of different ages is key as disk evolution very probably does not follow a unique path. | Disks around low-mass stars | Disks and planet formation | 2014-02-07T06:01:00.000 |
| 3797 | 2023.1.00196.S | 0 | The circumstellar envelopes of Cepheids and their impact on the PL relation at the JWST and ELT era | Cepheid variables are unique stellar physics laboratories and provide a crucial step in the cosmic distance ladder from the Milky Way Galaxy to the distant Universe. In particular, their circumstellar envelopes (CSEs) could bias the Period-Luminosity (PL) relation and provide constraints on the mass-loss history. We propose to observe the emission of the gaseous CSE of 6 bright Cepheids betweeen 211 and 275 GHz with the 12 m ALMA array. The objective is first to provide a physical model of the gaseous CSE and then to link the CSE properties to the evolutionary state of the stars in the instability strip. This will be used to constrain the mass-loss process at play in the framework of the mass discrepancy of Cepheids and to provide a grid of photometric corrections in the JWST bands to correct for the CSE effect on PL relation used in the extragalactic distance scale. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2025-07-27T18:26:38.000 |
| 3798 | 2019.1.00959.S | 549 | A systematic experiment to measure fundamental differences in the star-formation properties of red and blue quasars | A long-standing debate is whether red QSOs (rQSOs) are inclined blue QSOs (bQSOs) viewed through a dusty torus or whether they represent an earlier evolutionary phase. To test between these competing models we have undertaken a uniform selection of rQSOs and bQSOs and performed systematic multi-wavelength analyses, carefully controlling for luminosity and redshift. We have found that rQSOs are brighter in the radio (and more compact) and far-IR wavebands, ruling out the inclination model but providing good agreement to an evolutionary model. In this proposal we request 1.3mm continuum observations of 45 rQSOs and 45 bQSOs at z=1.5-3, matched in 6um luminosity and redshift. With these data we will fit the broad-band 10-1300um SEDs (including WISE+Herschel) to measure star-formation (SF) luminosities. With these measurements we will search for fundamental differences in the SF properties of rQSOs and bQSOs, from both individual source comparisons and fitting the SF luminosity distributions. We will also compare these SF properties to coeval X-ray AGN from our previous ALMA program to place rQSOs and bQSOs within the context of the overall AGN population. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-03-25T03:51:23.000 |
| 3799 | 2017.1.00995.S | 4 | S2 Flyby of SgrA*. Shining a Light on the Black Hole | We propose to use the close flyby of the S2 star by the galactic center to shed light on the properties of the immediate environment of our galactic center black hole SgrA*. S2 is 200 times brighter in ionizing radiation than SgrA* and will ionize the nearby material which might otherwise be neutral and therefore invisible in both X-rays and recombination lines, illuminating the inner workings of the galactic center black hole. The HI 30alpha recombination line emission provides a direct and reliable probe of the cool (non X-ray emitting) ionized gas, which likely constitutes the bulk of the accretion reservoir of SgrA*. The ALMA sensitivity is such that it is capable of detecting < 1 Jupiter mass of HII in the accretion zone at less than 0.01 pc. It is a once-in-16-years opportunity, and should not be missed. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2019-05-25T20:58:48.000 |
| 3800 | 2018.1.01119.S | 36 | Constraining the Vertical and Radial Structure of the Turbulence around DM Tau | Turbulence is a fundamental parameter in models of grain growth and planetary evolution and while observational constraints are challenging, our initial studies of the disks around TW Hya and HD 163296 have demonstrated the ability of ALMA to tightly constrain turbulence. Recently, using CO(2-1) data from our ALMA cycle 4 program, we have found significant non-zero turbulence in the disk around DM Tau. This is the first detection of turbulence within our sample, but our knowledge of its radial and vertical structure is limited by the fact that CO(2-1) is most sensitive to gas in the upper layers of the outer disk. We propose to build on our turbulence detection with observations of N2H+(3-2) (sensitive to cold gas near the midplane where CO is frozen out) and CO(6-5) (sensitive to warm gas higher in the disk and closer to the star than CO(2-1)). This combination of emission lines will provide an empirical measure of the vertical and radial structure of turbulence, as well as a more complete understanding of the physical source of the turbulence, the role of turbulence in planet formation, and the outward transport of angular momentum. | Disks around low-mass stars | Disks and planet formation | 2019-11-23T12:43:28.000 |
| 3801 | 2018.1.01476.S | 850 | A systematic experiment to measure fundamental differences in the star-formation properties of red and blue quasars | A long-standing debate is whether red QSOs (rQSOs) are inclined blue QSOs (bQSOs) viewed through a dusty torus or whether they represent an earlier evolutionary phase. To test between these competing models we have undertaken a uniform selection of rQSOs and bQSOs and performed systematic multi-wavelength analyses, carefully controlling for luminosity and redshift. We have found that rQSOs are brighter in the radio and far-IR wavebands, ruling out the inclination model but providing basic agreement to the evolution model. In this proposal we request 1.3mm continuum observations of 45 rQSOs and 45 bQSOs at z=1.5-2.5, matched in 6um luminosity and redshift. With these data we will fit the broad-band 10-1300um SEDs (including WISE+Herschel) to measure star-formation (SF) luminosities. We will use these measurements to provide systematic comparisons of the SF properties of rQSOs and bQSOs, from both individual source comparisons and from fitting the SF luminosity distributions, to search for fundamental differences. We will also compare these SF properties to coeval X-ray AGN from our previous ALMA program to place rQSOs and bQSOs within the context of the overall AGN population. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2020-08-16T10:10:12.000 |
| 3802 | 2018.A.00003.S | 14 | Confirming the first detection of a merging binary supermassive black hole system in the early Universe | We have recently detected the first example of proper motion in a candidate binary black hole system at z=3 through high resolution radio imaging with Very Long Baseline Interferometry and by using the magnification provided by a gravitational lens. We find that the two radio-loud black holes are moving towards each other, with a current projected distance of just 100 pc. Here, we request ALMA-DDT observations with an angular resolution between 0.15-0.5 arcsec of the dust continuum emission and of the circumnuclear molecular gas. These observations will robustly confirm the binary black hole hypothesis and test dynamical models for this system. | Merging and interacting galaxies | Galaxy evolution | 2019-04-16T13:08:30.000 |
| 3803 | 2018.1.00495.S | 47 | Long-term Study of the Active Massive Protocluster NGC6334I | The 2015 discovery of a powerful millimeter outburst from the deeply-embedded massive protostar NGC6334I-MM1B (Hunter et al. 2017), which was accompanied by an unprecedented simultaneous flaring of multiple maser species (MacLeod et al. 2018), provides direct evidence for episodic accretion in a massive protostar. The contemporaneous drop in free-free emission from its hypercompact (HC) HII region signals a drop in the uv photon production rate consistent with bloating of the protostellar photosphere as predicted for high accretion rates. Follow-up observations of this amazing event will yield new insight into the formation process of massive stars. The large increase in luminosity (70 times, inferred from the dust heating) has persisted for 2 years, suggesting a long decay timescale, similar to an FU Ori event in low mass protostars, but surprises may be in store. Because the masers also remain in a flared state, we propose to monitor the evolution of the source luminosity, to further resolve the disk that is actively mediating the high accretion rate, and to acquire a higher resolution baseline continuum image for future measurements of the relative motions between protostars. | High-mass star formation | ISM and star formation | 2020-11-22T00:46:44.000 |
| 3804 | 2022.1.01054.V | 0 | Resolving Polarization in Sgr A* with GMVA + ALMA | While black holes are ubiquitous, our understanding of how strong gravity and energetic material interact to produce the light we observe remains limited. The Galactic Center supermassive black hole, Sagittarius A* (Sgr A*), is the most promising target to study the dynamics of black hole accretion and outflow via direct imaging. Cycle 4 (2017) results revealed a nearly isotropic intrinsic source with an angular size of ~12 Schwarzschild radii, constraining a set of emission models to disks or low-inclination jets. Cycles 4-5 measurements also confirmed that scattering effects will not dominate 1.3-mm VLBI images of Sgr A*. For Cycle 9, we request a full-polarization GMVA+ALMA imaging observation of Sgr A* at 3.5-mm, with a high-sensitivity polarization-focused sub-array. The VLBA provides key calibration and imaging input while we leverage the additional high-bandwidth capabilities of (sub)millimeter GMVA and guest facilities to detect polarization structure in Sgr A* on VLBI scales at 3.5-mm for the first time. The measurements will provide critical insight into the accretion flow configuration of Sgr A* and greatly improve our understanding of the intrinsic structure of Sgr A*. | Galactic centres/nuclei | Active galaxies | 3000-01-01T00:00:00.000 |
| 3805 | 2023.1.00127.L | 0 | Probing the molecular gas -- the missing puzzle piece to the baryon cycle | The interactions between gas and galaxies are of paramount importance to our understanding of structure formation. A fundamental element of such baryon cycle studies is a complete census of the condensed matter (stars and cold gas) in both galaxies and their immediate surroundings, the so-called circumgalactic medium. Probes of the neutral atomic gas HI, ionised gas and stellar component have been assembled for of a sample of 48 galaxies. Without a quantitative description of the molecular phase however, one cannot reach a full census of their baryons. ALMA's unrivaled mm coverage and high sensitivity is ideal to characterise the CO emission of these z~0.5 HI-selected galaxies. By measuring the molecular mass, kinematics, gas flows and gas fractions, the project will: i) determine the role of molecular gas in HI-rich galaxies, ii) decipher the molecular phase of gas flows from morpho-kinematics analyses, and iii) reach a complete census of the condensed baryons in the circumgalactic medium. These results will provide unique insights into the baryon cycle - a crucial component of galaxy formation. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE) | Cosmology | 2025-01-08T13:05:31.000 |
| 3806 | 2016.1.00147.S | 49 | Is the Molecular Inflow in the Galactic Center Transient? | The Circumnuclear Disk (CND) is a 2-pc gas disk surrounding the supermassive black hole Sgr A* at the center of our Galaxy. The CND consists of several molecular cores with sizes of 0.1 pc. The CND, being the final place of the molecular reservoir in the Galactic center (GC), is critical to our understanding of the feeding of SgrA*. Additionally, knowing the life time of the CND is paramount. Two key factors control this life time: (1) the tidal threshold by SgrA* exerted on the gas, and (2) replenishment from exterior gas inflows. Earlier low-resolution (beam > 24) data suggest that the CND is transient because of its low density. High-resolution (0.1 pc) data are awaited to confirm this. We found a molecular streamer, originating from the ambient clouds with progressively higher velocities as it approaches the CND, in our CS(2-1) map (beam=40" (1.5 pc)). This shows evidence of gas replenishment onto the CND. This rises the question whether the streamer consists of dense cores that are able to resist tidal disruption. We propose to obtain a 0.1 parsec resolution map to resolve the dense cores feeding the GC along the streamer and its parent cloud with various density tracers. | Galactic centres/nuclei | Active galaxies | 2018-05-20T03:55:25.000 |
| 3807 | 2021.1.01019.S | 39 | High Resolution Observations of the Molecular Gas in AGN Hosted by Major Galaxy Mergers | We propose high resolution (0.05", ~50pc) CO(2-1) observations tracing the molecular gas in the nuclear regions of 4 nearby major galaxy mergers hosting single/dual AGN. These systems trace a range in nuclear separations, and hence merger evolutionary stage, from 0.2 to 4 kpc and represent a >10x improvement in spatial resolution over existing CO data, allowing to resolve the structure of the molecular gas inside the sphere of influence of each supermassive black hole (SMBH) and study individual giant molecular clouds in the circumnuclear medium. Our main scientific goals are: (i) trace the molecular gas dynamics in regions well inside the SMBH's sphere of influence, (ii) study nuclear molecular outflows driven by the SMBH growth, and (iii) measure the amount of gas and kinematics of the gas reservoir for each SMBH in connection to current and future SMBH growth. By sampling both single and dual AGN in similar merger stages, we will study possible structural differences in the gas fueling SMBHs, explaining their contrasting accretion rates. In future cycles more systems will be studied, to draw statistical conclusions once more ALMA high resolution time is available. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2022-11-19T23:57:23.000 |
| 3808 | 2015.1.00354.S | 21 | Detection and Characterization of Fragmentation in a Class 0 Disk | Fragmentation of protostellar disks can have profound consequences for both star and planet formation. Disk fragmentation can lead to cycles of episodic protostellar mass accretion featuring short-duration, high-amplitude bursts that significantly impact the chemistry of the surrounding core and planet-forming disk. Fragments can be ejected from the disk, producing a second-generation population of proto-brown dwarfs and very-low-mass protostars, or settle onto stable orbits, giving rise to wide-separation giant planet and brown dwarf companions. However, it remains unclear if disks can grow massive enough to fragment in the embedded protostellar stage of evolution. The best candidate for a fragmenting protostellar disk is Serpens-FIRS1, an intermediate mass, Class 0 protostar with a disk that is at least 50% as massive as the central protostar and shows tentative evidence for fragmentation in ALMA cycle 2 data. We propose to obtain band 6 continuum, C18O, and 13CO (2-1) observations of Serpens-FIRS1 at 0.14" resolution in order to directly image a fragmenting protostellar disk, confirm the existence of Keplerian rotation, and measure the mass of the protostar. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2018-01-24T13:17:42.000 |
| 3809 | 2012.1.00275.S | 0 | Vertical Stratification of Turbulence in Protoplanetary Disks: the CS tool | Turbulence is thought to be a key ingredient for angular momentum transport, mixing processes, and planetesimal formation in protoplanetary disks, but was rather poorly constrained by molecular line observations. We recently used CS (a ``heavy'' molecule for disks) to separate the thermal and turbulent components of the local line width in DM Tau, and obtained unambiguous determination of the (radially averaged) turbulent motions. The turbulence magnitude is high, around Mach 0.5, in contrast with derivations from viscous spreading of disks, or accretion rates. This may be the first evidence for a vertical stratification of the turbulence in protoplanetary disks. We propose here to use the unique combination of high spatial and spectral resolving power and sensitivity of ALMA to image CS 5-4 (and incidentally CN 2-1 plus two lines of HC3N) to go one step further and probe the radial dependency of the turbulence in the disk around DM Tau. | Disks around low-mass stars | Disks and planet formation | 2015-03-12T12:39:37.000 |
| 3810 | 2017.1.00123.S | 67 | The interstellar medium of Hot Dust Obscured Galaxies at z = 3.1-3.6 | This proposal aims to study the molecular and atomic gas properties of hot, dust-obscured galaixes (Hot DOGs). These extreme luminous galaxies, which were discovered with the WISE satellite, are rare class source characterised by a dominant hot dust component from a central obscured AGN. Analysis of the far-infrared spectral energy distribution shows the presence of a luminous cold dust component, possibly associated with starburst activity. It has been proposed that the Hot DOGs represent a short-duration transition phase from starburst- to AGN-dominated stages in the evolution of massive galaxies. We have successfully obtained CO(4-3) detections of three Hot DOGs at redshift z>3. Our results reveal massive molecular gas reservoirs of 10^10-10^11 Msun, which is similar to SMGs. More importantly, we find that all three sources show multi-component systems at <3 kpc scale. This is indicative of on-going or recent merger activity. The proposed observations of CO(7-6), CO(9-8), [CI] and [CII] will provide unique insights to the conditions in the host- and companion galaxies. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-10-09T21:18:02.000 |
| 3811 | 2016.1.00140.S | 60 | Molecular Gas in Local Merging ULIRGs | Hierarchical galaxy formation scenario predicts that galaxy-galaxy interaction and merger are the fundamental process that are related to the evolution of galaxies in the universe, changing the galaxy morphology and triggering intense starbursts and/or AGN activity. Recent high resolution simulations have shown that tidal interaction is responsible for forming massive clumps of dense gas surrounded by diffuse gas clouds and triggering star formation across the galaxy disks. An observational test of gas response requires mapping both the diffuse and dense gas tracers in merging U/LIRGs at high spatial resolution. Here we propose a systematic CO(1-0), CO(3-2), HCN(4-3), HCO+(4-3) survey of 6 of the brightest merging ULIRGs in the local universe at 0.3 arcsec (200 pc) resolution of ALMA. The primary aim of this study is to map the distribution and kinematics of warm/dense molecular gas and the dense gas mass fraction and interpret their relation to star formation and AGN activities in the context of the merger-induced response of the ISM in the progenitor disks. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-09-15T00:00:00.000 |
| 3812 | 2021.1.00666.S | 119 | Testing theories of the excitation of CO in strongly star-forming galaxies | We request 10hrs with ALMA to observe the CO(6-5) emission from 20 dusty star-forming galaxies with published moderate-J (Jup=3/4) CO spectra, estimates of their star-formation rate densities (Sigma_SFR) based on angular sizes from their 870um dust continuum emission, and scheduled JVLA CO(1-0) observations. We will employ these observations to test the model proposed by Narayanan & Krumholz (2014) for the excitation of CO in star-forming galaxies, which predicts that the shapes of CO spectral line energy distribution (SLED) is primarily driven by the typical Sigma_SFR in the galaxies. Our sample of 20 galaxies spans an order of magnitude in Sigma_SFR and will provide a strong test of the claimed model, as well as allowing us to test empirical correlations of the CO SLED shape with other observables (far-infrared luminosity, dust mass, dust continuum slope) to determine the uniqueness of the proposed model. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-10-21T18:44:58.000 |
| 3813 | 2018.1.00597.S | 22 | Sub-kpc Imaging of the Star-forming Gas in two [C II] luminous Quasar Host Galaxies at z ~ 6 | We propose ALMA subkpc resolution imaging of the [CII] line and dust continuum emission from two of the most [CII] luminous quasars - ULAS J1319+0950 at z=6.13 and SDSS J2310+1855 at z=6.00. We also ask for subkpc imaging of the CO(9-8) line emission from SDSS J2310+1855. Our previous 0.3"~0.6" resolution [CII] images of the two objects reveal intense star formation from a rotating gas disk extended over a scale of a few kpc. The sub-kpc scale imaging proposed here will allow us to well resolve the disk and model the rotation velocity and inclination angle at different radii in details, address if there is any warped geometry, substructures or tidal features that might be the residual of recent galaxy merger. It will also separate the extended star-forming heated dust component from the compact (<1kpc) AGN-heated dust. Our recent CO (9-8) and (8-7) line detections in J2310+1855 suggest a highly-excited component which may be powered by the central AGN. These very high-J CO lines are more compact and show a different velocity field compared to that traced by the [CII] line. Thus the CO(9-8) line imaging proposed here is unique to probe the AGN feedback effects on gas dynamics. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2020-12-11T11:26:20.000 |
| 3814 | 2021.1.01209.S | 90 | The Origin and Impact of Flares in M Dwarf Systems | M dwarfs are the most common stars in the galaxy and have a high frequency of Earth-sized planets at an equilibrium temperature that places them in the habitable zone, making them favored targets of upcoming missions to detect and characterize exoplanets. Millimeter emission appears to be a common feature of M dwarf flares that remained undetected until now. Observations at these wavelengths offer the most direct method to observe emission from energetic particles in stellar flares. Here, we propose to obtain ALMA ACA observations of four nearby M dwarfs to constrain the properties of detected millimeter flares. We also plan to obtain simultaneous ground- and space-based optical and UV observations. Recent results suggest that UV and millimeter emission trace each other closely during flares, and this proposed study will show whether this is a universal property of mid-M dwarfs regardless of age. By deriving a scaling relation between millimeter and UV emission, we will have a powerful new tool to determine the UV environment of stars and their potential to host habitable planets, and be able to capitalize on existing all-sky cosmology surveys at millimeter and radio wavelengths. | Main sequence stars | Stars and stellar evolution | 2023-10-22T17:40:02.000 |
| 3815 | 2021.1.00252.S | 10 | Star Formation Under the Cosmic Microscope with JWST + ALMA | The James Webb Space Telescope (JWST), through the Directors Discretionary Early Release Science (ERS) Program, is going to spend 55 hours observing four gravitationally lensed starforming galaxies to spatially resolve the stellar components and the star formation in galaxies across the peak of cosmic star formation (1.3 | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2022-12-29T16:53:13.000 |
| 3816 | 2022.1.01160.S | 5 | Resolving the disk-jet accretion connection for forming massive stars | Since the discovery of dust-continuum and maser-line outbursts from a handful of massive forming stars, there has been an accompanying burst of scientific interest in variable accretion onto massive YSOs (MYSOs). Recent observations of highly structured and unstable disks around MYSOs have provided a possible mechanism to explain their episodic accretion. An additional record of their recent accretion history can be derived from observations of jets. We propose to observe six MYSOs with ionized jets selected from the Red MSX Source survey with both ALMA and e-MERLIN to resolve the jet and accreting structures down to a matched resolution of ~40mas (~100au). With our proposed ALMA 1.2mm observations, we will determine the circumstellar density, temperature, and dynamic structure, combining these to assess the stability of any rotating structures we find. The ongoing e-MERLIN survey will resolve the jet knots, width, and collimation region. Comparing these to look for trends in the jet and circumstellar properties and structure, we plan to observationally confirm whether there is a connection between unstable disks with sub-structure and episodic jets with multiple knots. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2024-12-06T00:47:45.000 |
| 3817 | 2022.1.00859.S | 9 | Exploring molecular clouds in the spiral arm region of M83 in [CI] | [CI] has been considered a global tracer of molecular gas as a substitute for CO on the galactic scale, whereas where and how it is emitted in the galaxy are not yet well understood. Recent [CI] observations toward M83 at ~400-pc scale revealed that the [CI] intensity is enhanced along the downstream and upstream regions of the molecular (i.e., CO) arm. The downstream enhancement suggests that [CI] is a photodissociation product of CO, whereas the upstream enhancement implies that [CI] appears bright in the earlier stages of the molecular cloud chemical evolution from CI to CO. Observations at GMC-scale (~50 pc) clarify the origins of [CI] enhancement in the arm. The resolution allows us to investigate the influence of UV radiation emitted from massive stars. It also permits detection of the spatial offset corresponding to the timescale conversion from CI to CO. We will investigate the dependence of the [CI]/CO ratio on the physical properties of GMCs by utilizing CO archival datasets. This study is the first to explore [CI] mapping to identify GMC-scale CI clouds directly in the disk of a nearby galaxy and serves as a benchmark for studying molecular clouds in [CI]. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2024-11-03T01:59:09.000 |
| 3818 | 2016.1.00048.S | 46 | A sub-kpc census of high-redshift dusty star formation | One of the most fundamental questions in astronomy is determining how galaxy growth occurred over cosmic time. While secular processes are believed to drive the bulk of this growth, it has long been assumed that the brightest dusty submillimeter galaxies are special, and are instead more similar to the merger-driven ULIRGs observed in the local universe. Now, our recently delivered Cycle 1 data have allowed us to map the obscured star formation on kiloparsec scales in a sample of 17 high-z galaxies for the first time. These stunning data reveal extended, disk-like light profiles with low Sersic indices - painting a very different picture from that seen in z=0 ULIRGs. Interestingly, pushing the resolution of the images as far as possible reveals an intriguing hint of low-S/N clumps. Here, we request high-fidelity sub-kpc (0.07arcsec/550pc) Band 7 mapping of our six brightest sources to conclusively confirm or refute the existence of this clump-like structure. This high-S/N sub-kpc census is necessary to definitively determine the distribution of the star formation in these dust-obscured sources and will make optimal use of ALMA's increasing capabilities. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-09-21T14:25:01.000 |
| 3819 | 2018.1.01066.S | 14 | Confirming the planetary nature of candidate companions in the cavity of HD135344B | The detection of accreting protoplanets in their thermal IR emission is notoriously difficult, and requires extreme high-contrast technology and substantial image filtering. The close-in point sources could also contain residual disk emission, and the conversion of luminosity to mass is very model dependent. However, with ALMA we can detect the distinctive kinematical signatures of the circumplanetary disks (CPD) around IR protoplanet candidates, and thus measure the mass of the compact bodies. Thanks to state-of-the-art coronography at Keck and VLT, we have detected point sources inside the cavity of the transition disk around HD135344B. With ALMA long-baseline angular resolutions, and informed by 3D numerical simulations, our predictions show that the impact of CPD kinematics are measurable in C43-9. After 7 years of ALMA operations, the timely measurement of a protoplanet dynamical mass will provide the planet formation community with much needed observational input. | Disks around low-mass stars | Disks and planet formation | 2023-05-14T00:00:00.000 |
| 3820 | 2024.1.00320.S | 0 | Investigation of the molecular environment that caused fewer high-mass stars in the Small Magellanic Cloud | The physical processes that dictate the fragmentation of a giant molecular cloud determine the stellar initial mass function (IMF). Numerical simulations show that a low-metallicity (Z) enviroment is expected to have inefficient cooling gas that forms fewer low-mass stars and flattens the IMF. The Small Magellanic Cloud (SMC) with Z<~0.2 Zsun exhibits a dearth of very high-mass stars from a full GAIA census of the whole galaxy, invoking the presence of a steep IMF. The new unbiased APEX CO(3-2) survey of the SMC, however, shows a flat cloud mass function similar to the galactic environment forming massive stars and clusters. Though the unknown excitation conditions of CO(3-2) measurements prevent further investigation on differences among simulations and observed stars and gas. We request ACA+TP observations on a large cluster of CO clouds in the SMC's central Bar in Band 3+6 with the aim to infer physical conditions precisely and to achieve a resolution down to clump scales (2 pc), in order to assess if the cloud fragmentation differs from the Galaxy. The results would have profound and far reaching implications for star formation studies of the low Z early universe. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3821 | 2011.0.00318.S | 0 | Probing Dust and Gas within the Gap of the Protoplanetary Disk around HD 142527 | Observations of protoplanetary disks are essential to reveal realistic initial conditions of planet building as well as to obtain valuable insights into young planets through disk-planet interactions. A gap in a disk is one of the key structures since it is closely intertwined with disk dissipation mechanism including the tidal clearing by planets. We here propose Band 7 observations for a Herbig Fe star, HD 142527, to determine the basic properties of the gap. The remarkable morphology of the disk, suggestive of a link to a planetary system, has been known by our previous observations in infrared and submillimeter. In our ALMA observations, using 13CO (3-2) and C18O (3-2) lines, we will measure the gas kinematics, estimate the gas mass, and obtain the dust-to-gas ratio even inside of the gap. HD 142527 is one of the few sources that allow us to study disk gaps in Cycle 0 with the moderate angular resolution. Even in Band 7, we will be able to probe asymmetries in kinematics and spatial distribution of disk material within the gap. Our observations will bring significant information not only to discuss the possible planetary system but also to understand the evolution of the disk. | Disks around high-mass stars | Disks and planet formation | 2013-10-30T04:06:00.000 |
| 3822 | 2024.1.00803.S | 0 | First resolved ALMA imaging of carbon-rich Wolf-Rayet binary dust structures | Dust is of central importance to the cosmic cycle of matter. Carbon-rich Wolf-Rayet stars (WC) can be major contributors to the galactic dust budget, however the dust production mechanism and dust survivability remains uncertain. Recent JWST images revealed a striking series of 17 concentric dust shells in the WC binary WR140, demonstrating that the dust may survive deep into the ISM. ALMA provides important complementary information to JWST, however WR140 is too far North for ALMA characterisation. We propose instead to carry out the first resolved ALMA imaging of WC dust and gas structures with WR112, which will soon be imaged by JWST. Orders of magnitude more prolific in dust production than WR140, WR112 is already known to host inner dust shells from ground-based infrared imaging, and the marginally resolved SMA detection of dust and CO makes it the best WC binary for ALMA characterisation. The proposed observations will leverage the capabilities of ALMA to image distant, cool dust to test dust survival, track its temperature evolution, allow for geometric modelling to constrain dust formation conditions and study the role of WC stars in enriching the cosmic dust content. | Black holes | Stars and stellar evolution | 2025-11-05T02:20:43.000 |
| 3823 | 2018.1.00227.S | 270 | The Pre-Stellar Core Mass Function in a Strongly Magnetized Cloud | Star formation is a fundamental process for the cosmos, but with many open questions. There is no consensus on a general theory that can predict the stellar initial mass function (IMF), from given initial conditions of gas clouds. Development of such a theory requires testing by observations that span a range of environments, yet which are still able to resolve the individual units of star formation: self-gravitating gas cores. Here we propose to carry out an investigation of a protocluster gas clump Center Ridge 1 (CR1) within the Vela C giant molecular cloud (GMC) (d=0.7kpc) that appears to be strongly magnetized, since it shows a local minimum of sub-mm polarization angle dispersion. In particular, we aim to measure the core mass function (CMF) from sub-mm dust continuum observations and the pre-stellar core mass function (PSCMF), by utilizing N2H+ and its deuterated form N2D+. The results will be compared to similar studies that have already been started by our group to measure the CMF and PSCMF in massive Infrared Dark Cloud (IRDC) G028.37+00.07 (d=5kpc) and a massive embedded cluster G286.21+0.17 (d=2.5kpc) using the ALMA 12m-array. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-07-08T20:14:20.000 |
| 3824 | 2021.1.00548.S | 74 | Tomography of the peculiar Sgr C cloud: a higher density threshold for star formation in a highly turbulent environment? | The dense gas-star formation law is one of the fundamental relations in the study of star formation. It defines a density threshold of 10^4 cm-3 for star formation. However, it is challenged in the Central Molecular Zone (CMZ) of our Galaxy, where we find a huge amount of molecular gas of mean density 10^4 cm-3 but inefficient star formation, likely owing to an environment-dependent density threshold. Here we focus on a CMZ cloud, Sgr C, whose SFR is consistent with the dense gas-star formation law as opposed to other CMZ clouds. We propose to use multiple molecular transitions to investigate the 3D density structure of Sgr C, and compare the density components with star formation activities to detect the density threshold for star formation. If a higher density threshold is confirmed, this will (i) provide an explanation for the inefficient star formation in the CMZ, and (ii) inform the previously observed variations in the dense gas-star formation law. This will be the first spatially and kinematically resolved measurement of gas densities in a CMZ cloud, and will pave the way for a systematic survey of other clouds in the CMZ. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-10-15T20:44:36.000 |
| 3825 | 2017.1.00904.S | 131 | WISDOM: Measuring High-mass Supermassive Black Holes using CO Kinematics | Supermassive black holes (SMBHs) are key to understanding galaxy evolution, but the known empirical correlations between SMBH mass and properties of galaxies appear to break down at high masses. In previous work, we have shown that it is straightforward to measure SMBH masses by resolving the Keplerian rise of the galaxy rotation curves, using ALMA to trace the kinematics of the CO gas. As part of the mm-Wave Interferometric Survey of Dark Object Masses, we have identified a group of 9 promising targets that populate this high-mass region. Through measuring the SMBH mass, and spatially resolving molecular clouds near to the SMBH, we aim to shed light on how different evolutionary paths lead to the most massive black holes in our universe. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2019-10-02T14:25:10.000 |
| 3826 | 2017.1.00727.S | 79 | The First Detection of the Circumplanetary Disk with ALMA | We propose to detect the circumplanetary disks around forming planets for the first time, because these disks are the key to understand giant planet-, and satellite formation. With a series of hydrodynamic simulations coupled with radiative transfer and the ALMA simulator we investigated in what conditions circumplanetary disks can be detected and why previous attempts were unsuccessful. Higher sensitivity and shorter wavelengths are needed, because these disks are hotter than expected due to the accretional heating, shock heating, planet irradiation. Hence the best chance to detect them in Cycle 5 is band 9. Our targets are 3+2 known planetary candidates in the circumstellar disks of LkCa15 and HD169142, one of which was discovered by our group. We ask for Band 9 continuum observations (that are 1.44 times more sensitive this cycle than previously), and for CN(6-5) and 13CO(6-5) lines that can trace hot gas to ensure the highest chance for the circumplanetary disk detection. Combining these data together with our models, we will be able to estimate the properties of the circumplanetary disks and their planets (e.g. mass), as well as put some constraints on giant planet-formation. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2019-10-31T14:10:16.000 |
| 3827 | 2015.1.00206.S | 18 | Unravelling the enigmatic mass loss of Betelgeuse | Betelgeuse is the most prominent target for a detailed study of mass-loss in a massive red supergiant. We are engaged in a long term project to trace the ejected material from the photosphere to the interstellar medium, and understand its kinematics and chemical evolution. We assembled a unique data set, resolving the stellar surface and MOLsphere by interferometry, and the dusty envelope at larger distances. We observed oxygen-rich dust in thermal infrared (8-20 microns) up to 100 R* (~2.5"), and Herschel provided us with images of the dust emission between 15" and 7'. The dusty envelope of Betelgeuse follows an intricate pattern, with a major interface located between 0.5 and 1.0", where molecules condense into dust grains. ALMA will resolve for the first time this key dust formation shell, in the CO J=3-2 and other molecular lines. We will trace the kinematics of the gaseous component from the photopshere, to the dust condensation region, and up to the dust clumps observed in the infrared at several arcseconds from the star. The molecular kinematics are mandatory to understand mass loss and dust formation, and only ALMA can reach the necessary resolution and sensitivity. | Evolved stars - Shaping/physical structure, Evolved stars - Chemistry | Stars and stellar evolution | 2017-12-15T17:50:19.000 |
| 3828 | 2019.1.00623.S | 18 | Spectral line survey in the rest-frame 350 GHz band toward a lensed sub-mm galaxy at z=2.3 | Over the past decade, some unbiased spectral line surveys toward nearby galaxies have been conducted. The target galaxies cover a wide range in star formation activity, nucleus activity, and metallicity. Indeed, these surveys have revealed how chemical composition is sensitive to a specific geature of a galaxy. For instance, our recent line surveys toward the two dwarf galaxies, the LMC and IC10, have revealed characteristic chemical compositionin low-metallicity environments: less abundant nitrogen-bearing species, enhancement of CCH, and deficiency of CH3OH. Such chemical diagnostics of the local galaxies are now developing. However, high-redshift galaxies are still left unexplored from an astrochemical perspective. To overcome situation, we propose a spectral line survey in the rest-frame 350 GHz band toward a lensed sub-millimeter galaxy SMM J2135-0102 (the Cosmic Eyelash) at z=2.326. In our frequency settings, the lines of CCH, CH3OH, HCN, and HCO+ are included. These species are sensitive to UV radiation, cosic ray, and metallicity. We will obtain chemical template of high-redshift starburst galaxy and compare it with that of nearby galaxies and high-redshifr quasar. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-11-17T07:20:58.000 |
| 3829 | 2018.1.00858.S | 0 | Quiet Sun Flares | Despite what the term quiet suggests, the quiet Suns magnetic field evolves in time and it is therefore correctly speaking not quiet, but magnetic energy is permanently emerging and cancelling out resulting in flaring activity. These small energy releases (nanoflares) are speculated to heat the solar corona. While there have been extensive studies of these quiet Sun flares in EUV and X-rays, ALMA will give us the possibility to study their chromospheric response. ALMA observations from 2014 showed that ALMA is indeed capable of detecting the submm counterparts of quiet Sun flares. Here we propose an optimized ALMA run to compare chromospheric heating as seen by ALMA with the coronal signatures seen in X-rays and EUV. Chromospheric heating ahead of coronal heating suggests that the energy is first deposited in the chromosphere (i.e. beam heating). In such a case, the thermal energy content in the chromosphere should be large. A delayed chromospheric heating suggests that the energy is mainly released in the corona and chromospheric heating by thermal conduction. These observations will therefore provide essential diagnostics to understand the energy release process. | The Sun | Sun | 2020-10-30T14:36:42.000 |
| 3830 | 2018.1.00551.S | 116 | Evolved Stars and Shaping to Planetary Nebulae: the Role of SiO | The importance of binaries on stellar evolution has been recognized lately, but their effects on the close circumstellar environment is not yet known. The influence of a companion on the region near to the surface of Asymptotic Giant Branch (AGB) stars may play a pivotal role in the formation of aspherical Planetary Nebulae. SiO masers are usually found within the pulsating atmospheres of AGB stars at about 2 stellar radii, and trace the onset of stellar mass loss. Using ALMA long baseline science verification data, we have found for the first time that the SiO emission (both thermal and maser), can also trace binary wind interaction close to the star. In the case of Mira AB, the SiO emission traces a portion of a bubble wall formed by the interacting winds, within 10 stellar radii of Mira A. Here, we request to observe four binary systems containing an AGB star, and which have known SiO emission, in order to establish whether SiO emission in other binary systems is linked to wind interaction. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2020-10-19T00:16:05.000 |
| 3831 | 2021.2.00049.S | 85 | Completing 2.6-mm and 1.3-mm spectral scans toward the prototypical Seyfert galaxy NGC 1068 | We propose ACA stand-alone spectral scans in the 2.6-mm and 1.3-mm bands toward the nearby Seyfert galaxy NGC 1068. This galaxy shows prominent molecular gas concentrations along the grand-design spiral arms and bar-ends (Starburst Ring) and around the AGN (Circumnuclear disk), and thus an ideal laboratory to study the impact of AGN and star formation on the host galaxy's ISM and their interplay through mm/sub-mm lines. Because of its close distance (~13.7 Mpc) and the clear AGN/starburst contrast, NGC 1068 is one of the most studied extragalactic system with molecular lines. Indeed, ALMA has been observing this galaxy every cycle from cycle 0 that results in extremely rich ALMA 12m array archive in Band 3 and Band 6. However, lacking short spacing data (i.e., ACA) have a strong impact on the line flux measurements. This is critical in the context of astrochemistry because it prevents from measuring accurate line fluxes, i.e., column densities, from region to region of NGC 1068. The purpose of this proposal is to complete the Band 3 and Band 6 spectral scans by adding short-spacing information. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2023-05-19T17:21:17.000 |
| 3832 | 2021.1.00246.S | 1470 | A spectroscopic survey of a highly complete sample of bright submillimeter galaxies | Submillimeter galaxies (SMGs) selected at 850 micron are now believed to represent a key phase of stellar mass buildup for massive galaxies in the early universe. While theoretical models can now reproduce their number counts without invoking extreme physical conditions, the predictions of their redshift distributions have yet to converge, partly due to a lack of precise redshift measurements on complete SMG samples. Recent ALMA follow-up observations of single-dish-detected submillimeter sources have produced a highly complete (>90%) catalog of ~60 bright SMGs, and the pilot spectral scan to search for lines on the brightest 18 has yielded a >90% detection rate, already allowing falsifications of a few models. Together with the pilot, here we propose to triple the sample size, which is needed in distinguishing the surviving models. The data will also allow searches for line emissions from companions of the SMGs, testing the fraction of physically associated pairs which are predicted to be rare in models. Finally the measurements of mid-J CO transitions and CI(1-0) will allow statistcal studies of the ISM on this effectively a HyLIRG sample at z~2-4. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2023-08-05T11:36:11.000 |
| 3833 | 2019.1.01760.S | 12 | The first observational measurement of planetary migration | We propose high resolution observations at Band 3 and Band 7 of the protoplanetary disc in Elias 24 which is known from previous imaging at Band 6 to harbour a single deep gap with a bright exterior emission ring suggestive of the presence of a planet. These system characteristics are optimal for measuring the migration rate of the planet, leveraging the results of our hydrodynamical modeling which shows how the speed of planetary migration affects the multi-wavelength structures observed both interior and exterior to the gap. We use simulated observations to demonstrate, as a primary science goal, how the data will constrain the planetary migration rate and also present a raft of secondary science goals relating to the grain properties in the disc. Planetary migration during the protoplanetary disc phase is a fundamental ingredient in planetary system formation but has not to date been measurable in any waveband. Our simulations thus provide the basis for the first ever observational measurement of planetary migration. | Disks around low-mass stars | Disks and planet formation | 2023-05-07T00:00:00.000 |
| 3834 | 2019.1.01111.S | 114 | Dust evolution in the protoplanetary disk population of Ophiuchus | A long-standing problem in planet formation is the growth and radial drift of dust grains in protoplanetary disks, which is predicted to be too fast for planetesimals to form. A possible solution to this issue are pressure maxima in disks, which can traps grains and allow them to continue their growth. Recent observations have provided evidence for both radial migration and dust traps, but a large, homogeneous, multi-wavelength survey to study these processes is still missing. We propose to observe 32 protoplanetary disks in the Ophiuchus region at 3 mm with a ~0.2" resolution. These sources were previously resolved at 1.3 mm by the ODISEA ALMA survey with similar resolution. Together with archival observations, this will result in a sample of 43 disks observed at 1.3 and 3 mm, and allow us to: 1) improve previous dust mass estimates of these sources, 2) compare their sizes at 1.3 and 3mm, sensitive to radial migration, and 3) yield resolved maps of the spectral index of their emission. Combined, these results will probe spatial changes in grain properties and test the impact of different dust processes in planet formation. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2022-08-10T13:52:39.000 |
| 3835 | 2012.1.00789.S | 5 | Uncover Obscured Starburst Activity on The Central 200pc of NGC 253 | NGC 253 is a nearby prototypical starburst; intense massive star-formation activity has been taking place in its central region. We propose high spatial resolution (0.5 arcseconds) H30alpha observations toward the central region of NGC 253. H30alpha emission is almost free from interstellar extinction. This observation will firstly provide us real distributions and motions of young star-formation region. Immediate objectives of this observational study are as following. 1) Uncover obscured starburst activity. There is a discrepancy of star-formation rate estimation depend on method or used wavelength. That may be a result of heavy interstellar extinction. Deep H30alpha imaging will give unattenuated star-formation rate. Unattenuated star-formation rate will establish a basis for understanding star-formation activity in this galaxy. 2) Star cluster age estimation and natal interstellar matter. We will employ Halpha/H30alpha ratio for a indicator of age for massive stellar cluster. This ratio is an indicator of extinction and increase as cluster age. Younger cluster is deeply embedded in inter stellar matter, then Halpha emission should suffer large attenuation. Using this age indicator, we will be able to pick up young cluster. Consequently, we will be able to investigate ISM around a young cluster. That ISM shall be cluster's naive, and we can obtain information about formation conditions of massive star cluster. | Starbursts, star formation | Active galaxies | 2016-02-16T13:02:37.000 |
| 3836 | 2019.2.00110.S | 9 | An unbiased census of giant molecular clouds in the low-metal dwarf galaxy NGC 6822 | We propose to obtain a CO(1-0) map of the central 12' x 15' (1.7 kpc x 2.1 kpc) region of the low-metal dwarf galaxy NGC 6822 with a resolution of 11'' (25 pc), in order to build an unbiased catalog of giant molecular clouds (GMCs). The proposed depth is sufficiently deep to detect a molecular gas mass of ~9 x 10^4 M_sun even for an estimated CO-to-H2 conversion factor in NGC 6822, which is 50x larger than the Galactic value. The CO(1-0) map properties, i.e., angular resolution and gas-mass sensitivity, will be almost compatible to the existing wide-area CO(1-0) images of local well-studied galaxies including LMC (Nanten), M51 (PAWS), and M83 (ALMA), allowing us to make a direct comparison of GMC properties among these different types of galaxies. Our science goals are (1) Conducting a systematic search for non-star-forming massive GMCs, which is known to be significant in LMC/SMC, (2) Measuring GMC-YSO separations to assess the timescales for the association of GMCs with star formation, and (3) constraining the column density probability distribution functions to test if any external compression exists. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2023-01-21T16:37:10.000 |
| 3837 | 2022.1.00680.S | 11 | A deep molecular gas map at the node of the cosmic web at z=3 | In the early Universe, galaxies and supermassive black holes are believed to be fed by the gas filaments of the cosmic web. Therefore charting the molecular gas reservoir, the direct fuel of star formation, in the cosmic web filaments is of critical importance for understanding galaxy formation and evolution. For this purpose, the z=3 SSA22 proto-cluster core provides an ideal target. Recent IFU observation uncovers hydrogen gas filaments on >1 physical Mpc scales, which undoubtedly show the remarkable filaments of the cosmic web. Here we propose very deep CO(3-2) mapping in ALMA Band3 toward the node of the filament. We will (i) dispose gas-rich galaxies around the most massive galaxy at the node, (ii) uncover how accreting streams of the cosmic web transform to molecular gas, and (iii) unveil environmental dependence on star-formation efficiency of galaxies in the filaments. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2024-05-11T16:52:33.000 |
| 3838 | 2022.1.00427.S | 10 | The Sunyaev-Zel'dovich effect toward a distant galaxy cluster at z=1.7 | We propose Band 3 observations of the Sunyaev-Zel'dovich effect (SZE) toward ACT-CL J0459.6-4946 at z=1.7, one of the most distant galaxy clusters confirmed to date. This object has been detected at high significance in SZE surveys by the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). The X-ray emission from diffuse hot gas is also well measured by XMM-Newton and Chandra. Our immediate objectives are i) mapping the projected gas pressure and reconstructing the inner pressure profile, ii) measuring gas temperature and density profiles in conjunction with existing X-ray data, and iii) searching for evidence of disturbances including shocks. This will be among the first such measurements at z>1.5 and can only be accomplished by deep ALMA+ACA observations. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2024-07-11T13:02:37.000 |
| 3839 | 2019.2.00132.S | 9 | Spatial Distribution of COMs within a Starless Core | Starless and gravitationally bound prestellar cores give a unique glimpse at the physical and chemical conditions prior to stellar birth when the initial conditions for star formation are set. The detection of complex organic molecules (COMs, such as acetaldehyde, methyl formate, dimethyl ether) in cold (10K) and dense (>10^4 cm^-3) prestellar cores has sparked interest in the fields of astrochemistry and astrobiology, yet the mechanisms for COM formation are still debated. New chemical models show that COMs appear in a shell around the densest part of the core, where methanol also shows its highest abundance. With single pointing observations of 31 prestellar and starless cores in the Taurus L1495 filament, we detect methanol (CH3OH) in 100% of the cores targeted and acetaldehyde (CH3CHO) in 68%, yet we still do not know the detailed spatial distribution of each species. In this pilot proposal we plan to observe one of these starless cores most strongly detected in acetaldehyde (core Seo9) with ALMA's ACA array in order to observe the spatial distribution of both CH3CHO and CH3OH in order to test the theoretical predications of COM formation. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2022-11-04T00:25:46.000 |
| 3840 | 2021.1.00518.S | 72 | Chemical survey of high-mass YSOs in the Small Magellanic Cloud | Studying the chemistry of the interstellar medium in different metallicity environment is important to understand the chemical evolution of the Universe. Dust grains play an important role in driving molecular cloud chemistry, therefore it's crucial to extend our study to low-metallicity environments. High-mass YSOs in the Small Magellanic Cloud are excellent targets and sub-pc resolution observations are feasible for them with ALMA. Previous projects targeted 2/3 of the spectroscopically confirmed YSO sample, but so far not hot core was detected. Here we propose ALMA Band 7 observations to complement the chemical survey of the spectroscopically confirmed YSOs in the SMC. We target SO2, HCO+, H2CO, CH3OH, HNCO, H2CS, NO, etc. lines to identify hot cores and we will compare the fractional abundances of the detected molecules to that of the hot cores in the Galaxy and in the Large Magellanic Clouds. The results will help us to better understand the chemical processes in the low metallicity environment, which characterised the early Universe. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2023-08-29T21:29:29.000 |
| 3841 | 2016.1.01554.S | 27 | Resolving Water Emission in the Early Universe | We propose to image water (988 GHz) and infrared luminosity in three strongly-lensed starforming galaxies at z~3 from the SPT survey. With the aid of gravitational lensing, we will achieve kpc spatial resolution in the source plane in Bands 6 and 9 with 0.5 arcsecond angular resolution. This will be the first time the L_H2O/L_IR correlation and dust temperature will spatially resolved in galaxies at high redshift. These observations will provide a powerful constraint on the kinematics of the FIR field and help understand the relation between star formation and star formation potential at high redshift. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2018-02-17T16:08:23.000 |
| 3842 | 2016.1.00721.S | 17 | Probing the Physics Behind Enhanced Star Formation in the Early Universe | We propose a survey of [CII] 158 micron emission from eight normal star-forming galaxies with spectroscopically confirmed redshifts of z=5.8 to 7.66. This emission line provides a unique tracer of the dynamical mass in these galaxies, which can constrain the total amount of gas present. We will use these observations to answer the question of whether an increase in the typical gas mass fractions with increasing redshift is the dominant physical cause behind an observed increase in the stellar-mass to halo-mass ratio at z > 5. These observations will also have tremendous legacy value, as they will probe the evolution of the ratio between [CII] and far-infrared luminosity to the highest redshifts. Finally, by observing the luminosity of this line at such high redshifts, we will pave the way for the future use of ALMA as a redshift machine, as [CII] represents the best chance for spectroscopic redshifts in the epoch of reionization, where Lyman alpha has become difficult to observe. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2018-05-11T19:22:31.000 |
| 3843 | 2019.1.00475.S | 289 | Cycle 7 Monitoring of the Sub-mm Brightness in the Inner Envelopes of Known Variable Deeply Embedded Protostars | We propose to use the standalone mode of the ACA to obtain band 7 continuum observations for 4 epochs over cycle 7 of three known variable protostars and 5 stable calibrator sources in the Serpens Main Cloud. This is an extension of our ongoing cycle 6 monitoring of the same sources. The observations will take place contemporaneously with the JCMT Transient Survey, which observes the region at a two to four week cadence. The ACA will monitor the brightness evolution in the inner envelope where the dust responds explicitly to changes in the source accretion luminosity. At the distance to Serpens Main of ~436pc, our ACA observations will resolve scales of ~3.8"/1600 AU and recover scales as large as ~19.7"/8200 AU, complementing the JCMT's angular resolution at 850 microns of ~14.6"/6000AU. Thus, comparison between the JCMT and ACA observations will provide critical information on the structure of the envelope, its variability, and its environment. As well, any stochastic event that occurs during the cycle should manifest itself in the ACA observations weeks to months earlier than in the JCMT observations, providing an unambiguous probe of the dust response rate through the envelope. | Low-mass star formation | ISM and star formation | 2022-09-23T20:40:28.000 |
| 3844 | 2019.1.00216.S | 22 | Characterization of Io's Atmosphere | We request 2x5 hours of observing time in Band 7 when Io is at eastern and western elongation to observe SO, SO+, and many transitions of SO2 in Io's atmosphere at high spatial and spectral resolution to: --Determine the source regions of SO2 and SO and to compare their locations with simultaneously mapped volcanic hot spots --Constrain the gas temperature and SO2 column abundance --Determine Io's wind field --Search for and map the SO+ ion These observations will be used to understand the relation between Io's atmosphere with gas plumes, volcanic activity, surface frost, and the plasma torus. | Solar system - Planetary atmospheres | Solar system | 2023-08-26T00:00:00.000 |
| 3845 | 2012.1.01080.S | 0 | ALMA CO(1-0) survey of low-z H-ATLAS/GAMA galaxies | We propose to use ALMA in Band-3 to detect the molecular CO(1-0) line emission in a sample of low-redshift (z=0.15-0.35) star-forming galaxies, all of which have been extracted from the H-ATLAS survey. Each galaxy has ubiquitous Herschel photometry from 100 to 500um and optical spectroscopy from SDSS and GAMA surveys, providing a uniquely suited blind survey for studying the various dependencies for the CO(1-0) line emission. Our sample has three main advantages with respect to IRAS samples: (1) it is not biased towards warm dust temperatures; (2) it explores a lower range of far-IR luminosities; (3) it has physical sizes (~<6'') which provide an easy detection with a single ALMA pointing. We have measurements of metallicity, stellar mass, dust mass, Halpha luminosity, extinction, far-IR luminosities, and several other physical parameters. Using this early `survey science' with ALMA our immediate goals will be to describe: (1) the basic correlations between between CO(1-0), star-formation rate (from far-IR and Halpha), mass, extinction and metallicity; (2) the conversion factor of CO luminosity into molecular gas mass (M_H_2), aided by dynamical mass measurements from the CO profiles; (3) the nature of the `main-sequence' for star-forming galaxies in terms of the efficiency traced by L_FIR/M_H_2. | Surveys of galaxies | Galaxy evolution | 2015-03-19T15:12:50.000 |
| 3846 | 2013.1.00663.S | 12 | Unveiling the gas and dust structure of the planet forming candidates SZ91 and MYLup | Despite the large number of extrasolar planets that have been identified in the last decade, we still struggle to fully understand the planet formation process. The identification and characterization of protoplanetary disks that are currently forming giant planets can provide the most direct observational constraints on the theories of planet formation. From our large survey of transition disk systems in Lupus, ALMA Cycle 0 data, and VLT/NaCo sparse aperture masking observations, we identified two transition disks that are excellent candidates for harboring forming planets. We here request 0.5 hours of ALMA observations of Sz 91 and MY Lup in band-6 to measure the gas mass of these disks and 1.8 hours in band-7 to resolve the structure of the inner disks where planet formation could take place. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2016-07-31T10:13:29.000 |
| 3847 | 2023.1.01688.S | 0 | The Unbiased LIne Survey of Supergiant Evolved Stars (ULISSES) | Massive stars are the main drivers of Galactic evolution. Their strong UV fields and conspicuous mass-loss influences the structural, dynamical and chemical evolution of the ISM. However, despite their relevance, many evolutionary aspects of these gigantic stars are still uncertain. In their post-Main Sequence evolution, a rapid succession of unstable, mass-shedding stages unveils a complex puzzle that can only be completed from a phenomenological perspective, i.e. investigating the interplay between these stars and the surrounding medium. This pilot project will study the molecular footprint of the different late evolutionary stages of the most massive stars. We plan to use ACA to map the molecular emission in the outskirst of a well balanced sample of 20 evolved objects (Yellow Hypergiants, Blue Supergiants, Luminous Blue Variables and Wolf-Rayets). This work will provide an unprecedented homgeneous snapshot of the molecular environment of evolved massive stars, providing invaluable insights about the chemical signature of each evolutionary phase, the dust lifecycle and the dynamics and structure of the circumstellar material. | Hypergiants, Evolved stars - Chemistry | Stars and stellar evolution | 2025-08-07T12:27:37.000 |
| 3848 | 2016.1.00202.S | 2 | Dynamics and energetics of the quiet-sun solar chromosphere | This proposal seeks to test models for heating the quiet solar chromosphere. The highly structured and dynamic chromosphere is poorly understood yet crucial for understanding energy transport in the solar atmosphere. Millimeter wavelengths have the advantage over all other diagnostics that they measure temperatures directly, important for studying the energetics of the chromosphere. They also are unique in sampling the gas at all chromospheric temperatures. We propose observations of the quiet Sun aiming to determine whether (magneto-)acoustic waves propagating upwards from the photosphere form shocks in the middle chromosphere, as predicted by most simulations. Such shocks would dissipate energy in these layers, thus providing a heating mechanism. We request Band 3 and 6 observations at the highest available spatial resolution to both look for the oscillations themselves, and to look for transient bright features indicative of shocks. Bands 3 and 6 penetrate to very different layers in the chromosphere, with Band 3 being hotter and higher, so if this mechanism is important we would expect to see stronger oscillations and more prominent shock features in Band 3 than in Band 6. | The Sun | Sun | 2018-08-07T00:00:00.000 |
| 3849 | 2022.1.01131.S | 26 | Resolving disks and mergers in the Epoch of Reionization | We propose deep, high angular resolution band 6 observations of [CII]158mum in six star-forming galaxies at z~6.5-7.7. These galaxies were recently spectroscopically confirmed through [CII] (at low angular resolution) and they are among the brightest known [CII] emitters in the Epoch of Reionization (EoR), while still representative of `normal' star-forming galaxies (log(LIR/Lsol)<12). We will derive the kinematics of these galaxies at a very early stage of galaxy formation and test if these distant systems are forming their stars in well-ordered, gas-rich disks or if they are dominated by turbulent gas motion. This analysis will yield the first measurement of the disk fraction in the EoR and reveal if smooth accretion from the cosmic web or major mergers contribute most to the build-up of stellar and baryonic mass 700 million years after the Big Bang. The observations will simultaneously reveal any outflows, if present, and we will investigate the morphology of the gas and dust with respect to the stars that are visible in the rest-frame UV and optical from upcoming Cycle 1 JWST observations. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-05-24T08:59:54.000 |
| 3850 | 2022.1.00195.S | 29 | Golden Reference for Metallicity Measurements at z=6-7 by ALMA+JWST | We propose deep [OIII]88um, [NII]122um/205um spectroscopy targeting two remarkably bright, lensed sub-L* galaxies at z=6.07-7.13 recently discovered with ALMA [CII]158um observations. JWST NIRSpec IFU observations have been scheduled for both galaxies targeting rest-frame optical lines. Our prime goal is deriving gas-phase metallicities at z>6 based on the robust direct electron temperature method. Although the direct method usually relies on temperature-sensitive auroral lines that are too faint to detect from sub-L* galaxies at z>6, the strong lensing and joint analysis of ALMA+JWST allow us to accomplish this goal by combining measures of the density-sensitive lines of [NII]122um/205um and temperature-sensitive lines of [OIII]88um (ALMA) and [OIII]5007 (JWST). Our program will offer robust measures of the metallicity in typical galaxies with Mstar~10^9 Msun at z~6-7, for the first time. Strongly lensed properties will also allow us to probe the metallicity gradient within the galaxies. We also characterize the obscured properties by securely constraining the dust temperature via the underlying continuum at rest-frame 88um, 122um, 158um, and 205um. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 2024-09-12T16:15:37.000 |
| 3851 | 2013.1.00426.S | 33 | Are faint proto-planetary disks still very dense ? | The majority of disks around Class II low mass stars are faint (Flux < 30 mJy at 1.3 mm at the Taurus distance). We recently demonstrated, through high resolution imaging at the IRAM array, that their very small size is the principal reason of the low flux detected. Half of them remain unresolved (< 20 AU radius), and may still be optically thick. Such compact, dense dust cores may be the first direct evidence of the theoretically expected magnetically dead zone. We propose here to use ALMA to unambiguously resolve these dusty disks, providing a direct constraint on the dust opacity, as well as to probe their gas content through the imaging of the J=2-1 line of the three main CO isotopologues. | Disks around low-mass stars | Disks and planet formation | 2017-10-14T18:53:33.000 |
| 3852 | 2019.1.01664.S | 7 | Measuring optical depth of CO emission in AGN molecular outflows | We propose to observe 13CO 3-2 and CO 3-2 emission toward IRAS 10565+2448 to determine if CO lines in wings of AGN molecular outflow are optically thin or thick, which may lead at least a factor 3 to 5 overestimation of masses and mass loss rate of AGN outflowing gas. CO 1-0 absorption at blue wing toward nuclear non-thermal continuum, which is another method to obtain the optical depth of outflowing gas, is also requested. Since IRAS 10565+2448 is one of source with the most massive outflowing molecular gas, if CO lines from the line wings are optically thin, the mass loss rate of AGN molecular outflow will be reduced at least 3 to 5 time less. In the other words, quenching star formation with AGN molecular outflow will not be as efficient as claimed in past few years. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-07-21T12:36:37.000 |
| 3853 | 2024.1.01206.S | 0 | The origin and dynamics of molecular gas in central galxies of cool-core groups | Giant elliptical galaxies are often characterized by strong central peaks in their X-ray emission, signifying intensive cooling of the X-ray gas. If not reheated sufficiently by radio jets from their central SMBHs, the gas is expected to cool, forming an X-ray cooling flow that deposits atomic and molecular gas in the center. This process has been well studied in central galaxies of massive clusters where large amounts of molecular gas has been detected. However, molecular gas observations for groups are limited to a few systems, while cooling should be stronger and the impact of radio AGN should also be stronger in groups than in clusters. In this proposal, we selected a sample of 6 giant elliptical galaxies in nearby galaxy groups with the most extended Halpha nebulae. As 3 of them already have sufficient ALMA data, we propose new ALMA observations on the remaining 3 galaxies. Besides the 12m data to map the compact molecular gas clumps, we also request ACA observations to probe the more extended and diffuse component of molecular gas. These observations will help understand the distribution and kinematics of molecular gas cooling and AGN feedback cycle in galaxy groups. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 3854 | 2011.0.00243.S | 0 | The black hole - galaxy mass relationship at redshift 6 | We propose to observe two z=6.4 quasars to determine their dynamical masses and hence their ratios of black hole mass to galaxy mass. This observable is a key prediction for models of the early growth of black holes and galaxies and the physical interplay between them. Previous observations of this kind have focussed exclusively on the most massive black holes which are subject to a severe selection bias. Our observations will measure the [CII] interstellar cooling line luminosities and line profiles and dust continuum luminosities. From these observations we will derive quasar host galaxy masses, ratios of [CII] to far-IR luminosities, star formation rates and dust masses to understand the evolution of galaxies and black holes at the earliest epoch. | High-z Active Galactic Nuclei (AGN), Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2013-09-18T20:04:00.000 |
| 3855 | 2018.1.00938.S | 38 | The hot beginning of massive halos: SZ confirmation of a z=2.5 galaxy cluster | We propose ACA 93~GHz observations of the z=2.506 galaxy cluster Cl J1001+0220 to measure the Sunyaev-Zel'dovich signature of its X-ray detected intracluster medium (ICM). A dense cluster core observed right before the quenching of its galaxy population, Cl J1001 is our best candidate so far for the most distant virialized halo, observed early in its existence. This program aims at constraining the pressure profile of the ICM, at a pivotal epoch in its evolution. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2020-02-17T18:44:07.000 |
| 3856 | 2017.1.00612.S | 0 | Formation of star clusters revealed in an isolated environment in the LMC | We propose ALMA observations toward seven cluster-forming clouds in isolated environments in the LMC. These targets were observed by the HST, revealing the distribution of low-mass YSOs clustered around each high-mass YSO. We will observe 12CO, 13CO, and C18O (2-1) as well as the dust continuum to investigate the cloud properties associated with the clusters. With a complete sample of YSOs across their evolutionary stages by including the HST data, we can determine the star formation rates from direct counts of all stages of YSOs. The sample of the YSOs will be used to trace the star formation throughout the cloud to investigate the differences in cloud properties in terms of the star formation activity. The amount of turbulence in a clump would be the key to reveal the formation mechanism of high-mass stars. The proposed ALMA observation will allow us to carry out a comprehensive investigation of the formation mechanism of clusters and high-mass stars therein in a simple environment. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2019-11-19T18:19:13.000 |
| 3857 | 2018.1.01107.S | 2 | Protoplanetary Disk Masses and Grain Properties in the Orion Nebula Cluster | Rich clusters are the typical sites of star and planet formation in the Galaxy. Thus, a complete understanding of planet formation requires measuring protoplanetary disk masses in a rich cluster environment. The Orion Nebula Cluster (ONC) is the most readily-observable rich cluster. Our team has recently completed an analysis of approximately 100 protoplanetary disks with ALMA at 850 microns (Band 7) from a 1.5 x 1.5 arcminute mosaic of the inner region of the ONC. However, accurate determination of disk masses requires knowledge of the dust grain sizes, which are unconstrained with detections at only one wavelength. We will rectify this by measuring the brightness of these disks at longer wavelengths and computing their spectral indices. Thus, we propose follow-up observations at 3.1 mm (ALMA Band 3) of the same 1.5 x 1.5 arcminute region. Additionally, these longer wavelength flux measurements will more accurately reflect the total dust mass of compact disks that may be partially optically thick at 850 microns. Our observations can also reveal radial variations in grain sizes within these disks, furthering our understanding of dust growth and evolution. | Disks around low-mass stars | Disks and planet formation | 2021-03-31T00:00:00.000 |
| 3858 | 2023.1.01612.S | 0 | Searching for circumbinary discs around black-widow binaries with orbiting planets | Black widows are pulsar binary systems with ultra low-mass, non-degenerate companion stars that are being ablated by the pulsar wind. These systems form when matter is accreted from the companion star onto an old neutron star, spinning it up to millisecond spin periods. Candidate planets in wide, multi-year orbits have been detected orbiting 4 black-widow binary systems, of which 3 are visible from ALMA. While other planetary formation mechanisms are possible (e.g. pre-supernova formation, or even capture of free-floating planets), we believe these planets are evidence that material ejected from the black-widow system during Roche-lobe overflow and ablation forms a circumbinary disc, from which these planets formed, that may be detectable at millimetre wavelengths. The goal of this proposal is to search for the mm excesses produced by these discs. The detection of such a disc would solve the mystery of what happens to the mass lost from the black-widow companion, constrain the efficiency of mass accretion onto the neutron star, and reveal the origin of these mysterious pulsar planets. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2025-08-07T05:25:38.000 |
| 3859 | 2016.1.01346.S | 2371 | Galactic Census of All Massive Starless Cores within 5 kpc | Star formation research has still not revealed the initial conditions for high--mass star formation (HMSF). This is largely due to the lack of clear--cut examples of dense clumps that are bound to form stars but have not done so yet (high--mass starless clumps: HMSCs). While scattered, small sky patch searches have been made, no systematic galaxy wide survey that can place such searches on a statistical firm footing has ever been conducted. We have now performed a systematic search for HMSCs from the ATLASGAL 870mu survey that covers the entire inner Galactic plane which are dense and devoid of infrared sources up to 70mum. Embedded star formation will manifest via outflowing, shocked, and warm gas component with little or no evidence of cold gas towards dense cores. By weeding out such masqueraders, and revealing the extent of fragmentation in all HMSCs, a feat only achievable with a survey machine like ALMA in an ambitious but highly economical <10 hrs main array time, we will for the first time reveal the truly massive starless cores. We will obtain the most robust constraints to date on whether massive starless cores exists, their lifetime and the initial conditions for HMSF. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-09-21T14:25:01.000 |
| 3860 | 2022.1.01293.P | 0 | A Deep Search for Pulsars Orbiting the Black Hole Sgr A* | The discovery of even a single pulsar in a <100 year orbit around the supermassive black hole Sgr A* would provide provide an unprecedented laboratory for studying fundamental predictions about the nature of black holes. By carefully monitoring the arrival times of pulses from the pulsar over the course of its orbit, the mass, spin, and quadrupole moment of the black hole could be measured to exquisite precision. The measurements could be combined with horizon-scale observations to fully map the space-time around Sgr A*. We propose to use the ALMA phased-array mode at Band-3 to conduct the deepest ever mm-wavelength search for pulsars in orbit around Sgr A*. By observing at 94 GHz where any potential scattering is negligible, the proposed observations will be sensitive to the fastest-spinning pulsars missed by previous cm-wavelength searches. In addition to searching for pulsars in the phased-array mode, we will also use the visibility data to make full polarization maps of Sgr A* to study the magnetized plasma surrounding the black hole. | Pulsars and neutron stars | Stars and stellar evolution | 3000-01-01T00:00:00.000 |
| 3861 | 2022.1.01070.S | 540 | An Investigation of Circumstellar Gravel around post-AGB Stars | The recent discovery of large mm/submm excesses in a few post-AGB objects, inferred to arise in dusty disks with large masses of mm-size dust grains provides an exciting new probe of binary processes such as Bond-Hoyle/Wind-Roche-Lobe-Overflow accretion or common-envelope ejection that have been proposed to explain the formation of dense equatorial disks in these objects. Upper limits of <1"-2" for the sizes of a few sources rule out extended dust-shell models, showing that the dust is confined to compact structures. This proposal focuses on multiwavelength continuum observations (0.87 and 1.3 mm) of a statistical, flux-limited sample of post-AGB objects, in order to robustly determine the dust power-law emissivity index in the mm-to-submm wavelength range that characterizes the dust grains in these objects. We will constrain the extents of the emitting region (expected to be unresolved) and derive the masses of the large-grain population in these objects. These observations will allow us to test theories for the formation of disks and torii around post-AGB stars, and to solve the mystery of how such large grains can emerge on presumably short time scales in these systems. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-07-17T17:15:34.000 |
| 3862 | 2022.1.00287.S | 6 | Surveying the diversity of asteroid surfaces | The main asteroid belt population shows a remarkable diversity in composition and surface properties, which reflects the formation locations and subsequent collisional and dynamical evolution of these objects, as well as the space weathering of their surfaces. ALMA enables high spatial resolution measurements of asteroid thermal emission and polarization, providing a powerful new tool for asteroid surface characterization. The only three objects observed with this technique to date lie at the highly-processed and metal-rich end of the compositional spectrum. We propose to broaden the sample of objects observed with this technique by observing ten new targets over a range of spectral classes to understand how surface composition and thermophysical properties correlate with spectral type, and strengthen the link between asteroid spectral classes and their formation and evolutionary pathways. | Solar system - Planetary surfaces, Solar system - Asteroids | Solar system | 2024-11-17T17:18:22.000 |
| 3863 | 2019.1.01108.S | 26 | Does scattering reduce the apparent dust mass in protoplanetary disks? | We propose to observe the circumstellar disk around CW Tau at Band 4, 6, 7 and 8 to investigate the scattering-induced optical depth reduction. The optical depth at the millimeter wavelength have used to constrain the disk properties such as the mass of solids. The recent theoretical models have shown that the self-scattering of the dust thermal emission that have been usually ignored in the mass estimate reduces the observed optical depth in the millimeter wavelength significantly, which potentially results into the underestimate in disk mass. To investigate this mechanism and determine the disk mass taking it into account, we observe the CW Tau disk where the millimeter polarization caused by the self-scattering have been detected by the previous observation. Because the effect of scattering is sensitive to the observing frequency, the multi-wavelength observation is useful to tell whether this mechanism indeed operates or not. This mechanism potentially changes our previous interpretation of millimeter continuum observations and hence should be investigated using the object having strong possibility of high scattering albedo. | Disks around low-mass stars | Disks and planet formation | 2022-10-29T19:16:14.000 |
| 3864 | 2015.1.01531.S | 14 | Probing Venus lower-cloud level atmosphere with mm-wave continuum emission | Venus is entirely covered by a thick cloud layer (H2SO4 droplet) expanding at altitudes of 45-60 km. We aim to understanding the mechanism of cloud formation and how the cloud distribution varies in spatial and temporal by observing the spatial distribution of SO2 at the lower-cloud level (~45-65 km). SO2 is the source and partially sink of H2SO4 vapor, and its vertical distribution inside the cloud layer closely connects to the cloud microphysics. Recent satellite and ground-based observations have provided observational knowledge on SO2 below and above the cloud, but not inside. This proposal focus on that unrevealed altitude region of SO2: mm-wave continuum emission can sound the Venus atmosphere at 45-65 km thanks to relatively better transparency of Venus atmosphere compared to submm domain. And, SO2 has a number of weak absorption lines at mm-wavelengths, which create a broad absorption feature under the Venus atmospheric condition. We will obtain continuum emission maps of Venus using ALMA Band-3 and 4 with a high imaging fidelity. Taking the difference between different continuum wavelengths will enable us to constrain the vertical gradient of SO2 above 50 km. | Solar system - Planetary atmospheres | Solar system | 2017-04-14T13:13:24.000 |
| 3865 | 2023.1.00897.S | 0 | Disk Ionization Survey to Constrain exoplanet Origins (DISCO) | Ionization drives critical chemical and dynamical processes within protoplanetary disks, including the formation of water/organics and the distribution of disk material via accretion and magneto-hydrodynamics (MHD). Constraining ionization throughout a disk is crucial for understanding its planet-forming capabilities and the composition of resulting planets. Studies of individual sources suggest that disk properties and local environment could enhance or inhibit ionization. At the same time, small surveys (< 10 sources) do not yet reveal trends in ionization with stellar or disk properties. We propose to complete a survey of ionization tracers in 40 disks across the Lupus and Taurus star-forming regions. This statistical study of ionization is a crucial next step that could reveal trends in ionization across disk morphology, host star properties, and environment, and will inform ongoing and future studies of planet formation and exoplanet atmospheric composition. | Disks around low-mass stars | Disks and planet formation | 2025-09-13T05:13:46.000 |
| 3866 | 2018.1.00813.S | 19 | Studying hydrodynamic effects in the GW Orionis triple system | GW Orionis a PMS triple system, whose 3-D orbits and stellar masses have been constrained by our VLTI interferometric and radial velocity monitoring. We conducted SPH simulations to study how the stellar components are expected to sculpt the circumstellar disc. These simulations suggest that the system might be susceptible to the recently-postulated ``disc tearing'' effect, where the gravitational torque of a misaligned companion tears the disc apart into distinct planes that precess independently around the central objects. The propose ALMA observations aim to detect the disc tearing effect for the first time observationally, which should appear as a prominent ring of 100 mas diameter that is misaligned with respect to the outer disc. The continuum data will constrain the physical conditions and dust properties, while our CO data will image gas streamers that might have been launched due to binary-disc interactions. This will allow us to constrain fundamental hydrodynamic parameters, such as the disc viscosity, and to study hydrodynamic effects such as dust filtration under well-defined conditions, providing a unique benchmark for planet formation studies. | Disks around low-mass stars | Disks and planet formation | 2020-11-08T20:18:20.000 |
| 3867 | 2019.2.00085.S | 27 | Trace the molecular gas reservoir in ULIRGs with co-existing extreme ionized outflows and vigorous starbursts | Ultra-luminous IR galaxies (ULIRGs) are thought to represent the rapidly growing phase of massive galaxies before quenching of their star formation by powerful AGN-driven outflows. In order to examine the statistical AGN and outflow properties of ULIRGs, we have constructed an AKARI 90 um flux limited complete catalog of 1028 ULIRGs at z=0.1-1.0. Five ULIRGs in the sample show extremely fast outflows (v > 1500 km/s), which are the most powerful outflows observed among ULIRGs and AGNs at z<1. However, the star formation activities in the five ULIRGs are highly intense with SFR of 300-2000 Msun/yr, comparable to the SFR of high-z ULIRGs. The co-existence of the extremely strong outflows and the intense SF activities is conflicting with the classical AGN feedback scenario. One possibility is that although the AGN-driven wind is powerful, it has only affected the hot, ionized gas, but not affected the cold, molecular clouds in which star formation occurs. In order to reveal the physical explanation behind the co-existence of the strong outflows and SF activities in these ULIRGs, it is crucial to determine the status of molecular clouds with sub-millimeter observations. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-10-13T09:36:12.000 |
| 3868 | 2019.1.00771.S | 40 | Resolved [CII]/CO/dust survey of the star-forming ISM at z=2-4 | We propose the first systematic survey of the [CII]/CO/dust continuum on ~2 kpc-scales in a carefully selected sample of 8 z=2-4 DSFGs, with a total of 18 hours in Bands 3/8/9, following a successful pilot study of resolved CO/[CII] emission in a sample of 4(2) z~2.5 SMGs. By resolving the three main tracers of the star-forming ISM on 2-kpc scales in these bright, unlensed targets, this survey will be a dramatic improvement over the previous unresolved multi-tracer studies at z>2. This resolved multi-tracer study will: (1) determine the relation of [CII] emission to obscured star-formation, molecular gas and stellar populations (in combination with deep HST imaging); (2) test the applicability of local SF laws to z>2 systems; and (3) study the ISM properties on kpc-scales. By revealing the relationship of [CII] to the two key ISM tracers in these easily accessible z=2-4 galaxies, this study will have important implications for interpreting the increasingly common [CII] studies at redshifts >4. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2022-10-29T19:24:09.000 |
| 3869 | 2015.1.00631.S | 28 | SN1987A: high resolution shock, dust, molecular, and nuclear physics | SN1987A is the closest, best studied supernova in the modern era. Our team has demonstrated the revolutionary results that ALMA can provide by observing SN1987A. Instabilities during and immediately after the explosion lead to heterogeneous mixing of the chemically stratified stellar interior. After a short time, free expansion dominates, and the structure is frozen in. Recent models show blobs ~10^17cm=0.13arcsec in size today, and that the structure depends critically on explosion details such as asymmetry in the explosion and magnetic field. We propose to create 3-d maps of SiO and CO emission and excitation (from multiple transitions) at <0.1", the first direct observation of the explosion-mixed structure. These data will also provide important constraints on supernova ejecta chemistry, dust formation, and composition, when we compare SiO and SO to the high-resolution distribution of dust continuum. They will also reveal detailed particle acceleration physics: by mapping the spectral index of nonthermal emission, we will understand local magnetic field amplification, real-time synchrotron losses, and perhaps even find the mysteriously elusive pulsar wind nebula. | Evolved stars - Chemistry | Stars and stellar evolution | 2017-01-15T22:03:43.000 |
| 3870 | 2023.1.00747.S | 0 | Interface between plasma and molecular gas in stellar-merger eruptions | CK Vul or Nova 1670 is thought to be a remnant of a stellar merger from 350 years ago. It has a very complex circumstellar environment, whose structure bears information on the collision and subsequent evolution of the system since 1670. We try to decode this information by analyzing different subcomponents of the remnant. Most enigmatic is part of the nebula, where hot plasma and cool (17 K) molecular gas seem to coexist. Here, we propose to use simple comparative analysis of morphologies of the molecular gas traced by CO 1-0 in ALMA+ACA observations and optical maps of recombining plasma. Only ACA data are requested here. Our analysis will include information on radial motions of the two phases and is aimed at reconstructing their relative location in 3D. This will allow us to hypothesize on the origin of this interface (central photoionization vs local ionization by shocks) and reconstruct the dynamics of the eruption. | Post-AGB stars, Transients | Stars and stellar evolution | 2025-07-25T11:07:01.000 |
| 3871 | 2015.1.00302.S | 10 | Sub-Arcsec CO(3-2) Imaging of the z=2.8 Submillimeter Galaxy SMM J02399-0136 | We propose sub-arcsec CO(3-2) imaging of the molecular gas in the z=2.8 submillimeter galaxy (SMG) SMM J02399-0136, which is the very first SMG discovered with a confirmed counterpart. This remarkable system is a merger of two ultra-luminous infrared sources and contains practically all of the diverse elements that are found in samples of SMGs (e.g., multiple-component starburst, AGN, extremely red object, Ly-alpha cloud, and feedback from a QSO-driven outflow), but there are a lack of observations of molecular gas at sufficient spatial resolution to disentangle the nature of the source. Recent high-resolution VLA radio imaging along with ALMA continuum imaging of the system suggests a radio jet from the QSO may be inducing (or enhancing) star-formation in the nearby extremely red starburst source. Detailed imaging of the molecular gas with ALMA is required to study the possible interaction of the QSO with the red starburst region as well as the surrounding large blue Ly-alpha cloud, and will provide insight into key processes associated with the formation and evolution of galaxies. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-10-20T02:06:43.000 |
| 3872 | 2018.1.01292.S | 47 | Eclipse observations of Europa and Ganymede | Observing the satellites of Jupiter while they are in eclipse gives exquisite sensitivity to small-scale thermal anomalies on these bodies. In previous cycles, the poor timing of high resolution ALMA configurations and the short windows of observable eclipses have prevented such observations. In Cycle 6, the fortuitous alignment of deep observable eclipses and the C43-7 and C43-8 configurations allow such observations to be made for the first time. Our Cycle 3 observations have revealed a region at the north pole of Europa that is the most anomalously hot spot, potentially indicating near-surface liquid water. In contrast, our Cycle 4 observations have revealed that the poles of Ganymede are unexpectedly cold, suggesting regions of unusual thermal properties. Eclipse observations of Europa and Ganymede will uniquely determine the causes of these thermal anomalies. We propose a sequence of observations during eclipse and immediately thereafter to map the temperatures of these satellites at their coldest in-eclipse temperatures and then as they recover to their normal values, giving us a powerful probe into the causes and consequences of thermal anomalies on the Galilean satellites. | Solar system - Planetary surfaces | Solar system | 2020-12-23T18:44:18.000 |
| 3873 | 2024.1.01648.S | 0 | Constraining the opacity and compactness of accretion and jet flows in LLAGNs | The horizon-scale observations of M87 and SgrA* are well modelled by synchrotron emission from a thermal particle distribution function [eDF]. However on larger scale the observed spectra is in good agreement with a non-thermal eDF. Thus the question arises where and how the thermal particles are accelerated into the non-thermal distribution. For studying and addressing these questions simultaneous multi-frequency observations are crucial. We thus request Bands 1, 3, 6 and 9 ACA observations of 81 nearby AGNs. The radio to millimetre spectra will allow us to test different jet and accretion models and thus constrain the opacity of the flows. The high-frequency capabilities of the ACA will allow us to study the turnover-regime of the spectrum (transition between optically thick and thin emission). Thus capturing the spectral turnover position will not only provide a tight constraint on the particle distribution function (and possible acceleration mechanism) but will also allow us to estimate the contribution to the high-energy emission via the synchrotron self-Compton process. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 3000-01-01T00:00:00.000 |
| 3874 | 2016.1.00323.S | 17 | HIgh Resolution Observations of Dense Gas and Dust in NGC 34 | NGC 34, a nearby luminous IR galaxy (LIRG) with a Sy2 nucleus and a nuclear starburst (SB), represents a class of final stage mergers that are undergoing SB, AGN, outflows, and other extreme phenomena simultaneously in central ~100 pc just before transforming into ellipticals. Because of heavy dust obscuration and small linear scale, only high resolution ALMA observations can resolve these sources. NGC 34, with a favorite sky location (Dec=-12 deg) and a close distance (84 Mpc, 1" = 400 pc), is an ideal target for such ALMA observations. We propose to make high resolution ALMA maps (~0".04, corresponding to a linear scale of ~16 pc) of CO(6-5), CO(4-3), CO(3-2), 13CO(3-2), HCN(4-3), HCO+(4-3) lines and of the continuum at 435, 650, and 870 um in NGC 34 nucleus. These maps probe physical conditions of dense gas and dust in SB and AGN separately, and provide information on how the two activities are related to each other. We aim to answering questions such as: Is the SB occurring in a separate nucleus or in a circum-nuclear disk around the AGN? What are the physical conditions of SB associated gas and the gas in the AGN torus? Is there any dense gas outflow and what powers it? | Merging and interacting galaxies | Galaxy evolution | 2018-07-24T20:34:30.000 |
| 3875 | 2019.1.00678.S | 99 | How long do blue bulges last? | Observations of the nearby universe find that the masses of supermassive black holes (BHs; M_BH) are tightly correlated with host-galaxy bulge mass (M_bulge). Understanding the cosmic origin of this M_BH-M_bulge relation is one of the central tasks of extragalactic astronomy. Recent investigations by Yang et al. (2019) discovered that BH and bulge growth are strongly correlated for bulge-dominated galaxies over cosmic history. Therefore, if there is a sufficient amount of cold gas to maintain strong BH/bulge growth in these galaxies, the local M_BH-M_bulge relation can form naturally. We request ALMA band-3/4 observations of low-J CO lines to constrain the gas content of 10 bulge-dominated galaxies at z=0.5-2.5 from Yang et al. (2019). The proposed observations will allow us to robustly probe gas mass (M_gas) down to ~M_bulge. If the measured M_gas are generally higher than M_bulge, then significant BH and stellar growth can happen for these bulges; otherwise, they are on the tail end of their cosmic evolution. We arrange basebands properly for the best observational efficiency. This optimization leads to a total of 7.0 h (including 2.3 h overheads) exposure. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-05-14T21:52:28.000 |
| 3876 | 2015.1.01225.S | 19 | CO(1-0) Observations of IFU Selected Green Valley Galaxies | How the star formation of galaxies get quenched and how galaxies migrate from the star-forming sequence to the quiescent population remains one of the most prominent questions in extra-galactic studies. We have identified three objects in their transitional phase, the so-called `green-valley' galaxies, from a sample of the SDSS-IV integral field unit (IFU) survey MaNGA, which will ultimately yield spatially-resolved stellar populations and kinematics of ~10,000 nearby galaxies. These three targets represent different stages of transition according to their resolved star formation rate and stellar mass relation revealved by MaNGA data. Here we propose to observe these three green-valley galaxies with ALMA matched to the MaNGA resolution, in order to understand the role of cold molecular gas in the star formation history as well as the quenching process in galaxies. The resolved gas observations from ALMA, combined with the resolved stellar populations from MaNGA, will provide a unique dataset to probe the relationship between gas content, stellar mass, and star formation rate on kpc scales for transitional galaxies, allowing us to study where and when quenching starts. | Spiral galaxies | Local Universe | 2017-03-25T01:38:01.000 |
| 3877 | 2015.1.00399.S | 60 | Sub-kpc imaging of bright quasar host galaxies at z~7 | High redshift quasars are likely hosted by massive and luminous galaxies in the early universe. Recently we discovered several bright quasars at 6.56.5 with bright [CII] emission. Here we propose to obtain followup observations of this small sample at sub-kpc resolution (0.7 kpc or ~0.12") to, for the first time, address key aspects that cannot be answered with the available data: Utilising the unique capabilities of ALMA, we will be able to (1) constrain the morphology and kinematics of the emission line gas, (2) produce a map of the star formation as traced by the FIR, (3) look for possible recent merger events, (4) search for infall/outflow signatures and (5) derive a well-constrained dynamical mass. Observations of this small sample will thus greatly enhance our knowledge of and provide first statistics on the properties of the earliest massive galaxies when the universe was only ~800 Myr old. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2017-11-17T18:08:35.000 |
| 3878 | 2017.A.00024.S | 0 | Using CI gas to probe the dynamical origin, exocometary composition and gas evolution of the disc around HR4796 | The growing number of detections of CO gas around debris disc stars is challenging the paradigm that main sequence stars are devoid of circumstellar gas. In many cases, the detected gas must be of secondary (rather than primordial) origin, released by volatile-rich solid bodies in debris discs. Indeed, our new model of secondary gas production (Kral et al. 2016) can explain all gas observations around Beta Pic and most other gas bearing systems, and makes predictions for systems with no gas detected yet (Kral et al. 2017). Here we propose to confirm a tentative 3sigma detection of [CI] around HR4796A with APEX that is at a level consistent with the model predictions. This would allow us, for the first time, to constrain the volatile composition of exocomets in HR4796A and to confirm that the viscous evolution of debris disc gas requires MRI to be active. In addition this would demonstrate ahead of cycle-6 the potential of ALMA CI studies, both as a way to detect secondary gas (this would be the 4th CI detection), and as a way of probing interactions with planets in the inner regions through high resolution follow-up. | Debris disks | Disks and planet formation | 2018-11-16T15:06:28.000 |
| 3879 | 2021.1.01705.S | 232 | A mm snapshot survey of nearby young stars observed in scattered light | In the past years ALMA and scattered light observations have revealed a zoo of planet forming disk morphologies. Of particular value is the synergy between the two techniques, tracing different dust populations and vertical extends of the disk. While scattered light observations trace small dust particles, well coupled to the gas on the disk surface, mm-emission trace the bulk-mass of material close to the disk mid-plane. Recent studies of small scattered light surveys have found that there is a correlation between the dust-mass of the disk and the present sub-structures, with more massive disks typically showing gaps or cavities in scattered light. Such findings are still tentative due to small sample sizes of scattered light surveys, for which accompanying mm continuum data exists. In this program we propose to obtain low-spatial resolution ALMA Band 6 flux measurements of a unique sample of disks, which is currently targeted by scattered light surveys. All 29 targets stars in this sample show strong near or mid-infrared excess and have in some cases already been resolved in scattered light. The proposed flux measurements will critically allow us to constrain their dust masses. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2023-09-07T10:42:01.000 |
| 3880 | 2023.1.00515.S | 0 | A New Era in Disk Polarization: Substructures in HL Tau Resolved at Two Wavelengths | ALMA recently observed polarization in HL Tau with by far the highest resolution in any disk (35 mas or 4.9 au), with almost two order of magnitude more vectors than just about any other disk (>1000 independent vectors). These 870 um polarimetric observations reveal that substructure substantially changes the polarization. This suggest that it is very difficult to learn anything from polarization observations (e.g., polarization mechanisms and grain shapes/sizes) without high resolution. The high resolution observations show that polarization is due to both grain alignment and scattering, but the fit to the the grain parameters is degenerate. Via 75 mas (10.5 au) resolution Band 4 observations of HL Tau, we will solve for the degeneracies. We will be able to constrain how polarization is affected by substrucure, what definitively causes grain alignment in disks, and what the spatial dust distribution and dust sizes are in disks. Combined with 870 um observations, this polarimetric legacy datsaset will likely be the highest resolution that will ever be created by the current rendition of ALMA, and thus will be the most modeled dataset for dust polarization for years to come. | Disks around low-mass stars | Disks and planet formation | 2025-03-15T20:51:43.000 |
| 3881 | 2016.1.01243.S | 26 | Testing the dense gas scaling -- star formation rate scaling relation in resolved molecular clouds in NGC 300 | Within local Galactic molecular clouds, a Kennicutt-Schmidt relation between the star formation and mass surface densities does not exist. Instead, a dense gas scaling relation of star formation applies, which has previously been found to also hold for entire galaxies. This suggests that the dense gas scaling relation may be the more fundamental law of star formation. To test this scenario beyond the Milky Way, we have conducted a large survey of resolved Giant Molecular Clouds (GMCs) in the nearby galaxy NGC 300 in ALMA Cycle 2, observing in 12CO(2-1) at ~10 pc resolution. We also carried out short pilot observations in HCN(1-0) as a first attempt to measure the dense gas content, from which we obtained meaningful and interesting upper limits of the HCN/CO ratio. We now propose to use our fully analyzed ALMA Cycle 2 CO survey data to expand this dense gas study to both greater sensitivity, to ensure detections, and to a larger sample of 10 CO-bright GMCs, matching the sample size of the local clouds. The result will be the first measurement of the dense gas fraction in resolved GMCs in a nearby galaxy and a critical test of the dense gas - star formation rate scaling relation. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2018-04-19T20:21:43.000 |
| 3882 | 2015.1.00676.S | 16 | Contrasting Exoplanetary Systems by Resolving the Debris Disk around Denebola | Denebola (beta Leo) is only slightly more distant than Fomalhaut, of virtually identical spectral type and luminosity, and has a nearly equally prominent debris disk. However, its disk is 2-4 times smaller than Fomalhaut's. The Denebola disk has at least four spectral/spatial components, presumably reflecting the complexity of the planetary system embedded in it. We propose to use ALMA to determine the structure of this disk, probing the embedded planetary system and allowing a detailed comparison with Fomalhaut's disk to elucidate the causes for the differences in their structures. | Debris disks, Disks around high-mass stars | Disks and planet formation | 2017-10-27T01:29:10.000 |
| 3883 | 2022.1.01122.S | 11 | The Most Accurate Extragalactic Supermassive Black Hole Masses Ever Measured | We propose to make some of the most accurate supermassive black hole (SMBH) mass measurements ever beyond our own Milky Way in the early-type galaxies NGC1574, NGC4697 and NGC7052. With high angular resolutions (0.038"-0.096"), we can resolve the molecular gas accretion disks down to ~100,000 Schwarzschild radii, closer to the SMBHs than all existing megamaser and molecular gas measurements except one. In addition to these extremely precise SMBH mass measurements, we will probe with unprecedented detail the galaxy regions within the SMBH spheres of influence, all of which are within the Bondi radii. We will search for signatures of warps and/or non-circular motions that may be funnelling gas towards the SMBHs, elucidating the feeding of radio-loud and quiet systems, and we will constrain accretion disc models and their connection to the larger scale disks/fuel reservoirs, also probed here. | Galactic centres/nuclei | Active galaxies | 2024-11-27T14:39:16.000 |
| 3884 | 2015.1.00859.S | 33 | Polarization and Flaring Studies of Sgr A* and the Magnetar 1745-29 | One of the key questions related to the nature of emission from Sgr A* is whether there is a jet or an outflow emanating from this source. The evidence for a jet from Sgr A* has a direct bearing on models of broad band emission and the accretion onto Sgr A*. We have recently studied radio continuum emission from the region surrounding Sgr A* and tentatively detected a symmetric linear feature emerging from Sgr A* which appears to be partially polarized on a scale of few arcseconds from Sgr A*. We have also detected strong continuum emission from a pulsar (magnetar SGR 1745-29) which lies 2.4'' from Sgr A*. We propose to use the unique capabilities of ALMA to image the inner few arcseconds of Sgr A* in total and polarized intensity, establish the detection of a jet, determine the rotation measure of polarized radiation in two bands and search for submm continuum emission from the magnetar. Additional motivation of the proposed observations is to characterize the variable emission from Sgr A* across bands 3 and 6. These measurements will determine the collimated mass outflow rate and test the prediction that there will be time delay from Sgr A* between the available bands of ALMA. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-03-28T21:14:19.000 |
| 3885 | 2015.1.00793.S | 5 | Tracing the Origins of Nitrogen Bearing Organics Toward Orion KL | A comprehensive analysis of a broadband 1.2 THz wide spectral survey of the Orion Kleinmann-Low nebula (Orion KL) has shown that nitrogen bearing complex organics trace systematically hotter gas than O-bearing organics toward this source. The origin of this O/N dichotomy remains a mystery. If complex molecules originate from grain surfaces, N-bearing species may be more difficult to remove from grain surfaces than O-bearing organics. Theoretical studies, however, have shown that hot (T=300 K) gas phase chemistry can produce high abundances of N-bearing organics while suppressing the formation of O-bearing complex molecules. We propose here to map, in exquisite detail, the temperature structure and D/H ratio of the complex N-bearing organic methyl cyanide (CH3CN) toward the Orion KL hot core. If gas phase formation routes are significant at high temperatures, we will observe a decreasing gradient in the D/H ratio of CH3CN with increasing kinetic temperature. The proposed observations will shed light on the origin of all complex N-bearing organics in the interstellar medium. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-06-14T00:04:47.000 |
| 3886 | 2016.1.00053.S | 90 | Turbulence sets the initial conditions for star formation? | We have identified a cold, dense, high-mass molecular clump, G337.342-0.119, that is likely a progenitor to a high-mass cluster. With a turbulent Mach number that is intermediate between those measured in the Galactic Disk and the extreme Central Molecular Zone of our Galaxy, G337.342-0.119 represents an excellent clump in which to test turbulence theories that make predictions for the gas distribution before star formation has begun. We propose to obtain a 1mm mosaic of its dust continuum and line emission to determine the cloud- to core-scale column density distribution and gas kinematics. With the dust continuum observations we will test quantitative predictions of turbulent theory, specifically, the shape, mean, and dispersion of its column density probability distribution function and the theorteically predicted, environmentally dependent volume density threshold for star formation. Additionally, with the line observations we will investigate whether individual cores are gravitationally bound. Confirmation of these theories would demonstrate that turbulence dominates the initial gas structure in cluster-forming clumps. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-10-28T00:00:00.000 |
| 3887 | 2012.1.00019.S | 0 | Probing the merger remnant disk in the giant elliptical galaxy NGC5128 | Many large elliptical galaxies contain embedded disks of dust and gas, remnants of a merger with a smaller gas-rich galaxy. The physical properties of such disks, and the resulting initial conditions for star formation are very different from those in disk galaxies and star-burst galaxies. We will study these in detail by modelling the molecular gas in the embedded dusty gas disk ("dark band") of the only nearby giant elliptical, NGC5128 (host of the radio source Centaurus A). We will apply PDR and radiative transfer models to the optically thick 12CO and the optically thin 13CO J=1-0 and J=2-1 line transitions in maps of 20 pc resolution over the inner several kpc of the galaxy. From the maps we will deduce the mass and temperature, for individual clumps and as a function of radius, of the gas in the extended disk, and investigate the relation of the dense molecular gas conditions to the enhanced star formation in the disk. The proximity of NGC5128 and its present evolutionary stage about halfway between acquisition and final consumption of a gas-rich galaxy provide a unique opportunity to study an advanced merger state in detail. | Merging and interacting galaxies, Early-type galaxies | Galaxy evolution | 2015-05-07T00:00:00.000 |
| 3888 | 2015.1.01025.S | 12 | Investigating the dyncamics of a thermal starless core in the Orion A cloud. | We have discovered a thermal (dv=0.2 km/s) starless NH3 core surrounded by CCS emission in the Orion A Cloud. Although molecular clouds (cores) are generally non-thermally supported in the Orion A cloud, turbulence is almost completely dissipated in this dense object. A striking resemblance to the collapsing starless core L1544 in Taurus suggests that this core is on the verge of star formation. The JVLA observations in NH3 (4" resolution) revealed that there are clumpy structures within the NH3 core. Because revealing initial conditions of star formation is quite essential to study how the stellar mass is determined, how multiple star systems are formed, how protoplanetary disks are formed, it is of great interest to know how this core is fragmented and evolves into protostars. We propose to map this core in 3 mm dust continuum emission to scrutinize the mass distribution in detail at 1.5" spatial resolution. We also aim to observe the N2H+ (1-0) and CH3OH (2-1) lines, simultaneously. The observation of the molecular lines with 0.098 km/s velocity resolution will allow us to investigate details of fragmentation process and the dynamical state of the dense cold condensations. | Intermediate-mass star formation | ISM and star formation | 2018-02-01T12:44:52.000 |
| 3889 | 2019.1.01477.S | 4803 | A comprehensive ALMA Redshift Survey of the Brightest Herschel Galaxies | We propose to measure with ALMA redshifts of 72 of the brightest (S_500um>80 mJy) sub-millimeter (submm) galaxies from the Herschel surveys, complementing our survey in the northern hemisphere with NOEMA and extending recent ACA measurements. For most galaxies, we have ancillary data in the optical and near-infrared, that will be essential to perform a full analysis (e.g, lensing modeling) of these sources. The NOEMA and ALMA surveys will result in a homogeneous sample of 250 bright submm galaxies with reliable redshifts, improving survey size by a factor 5. This comprehensive survey will allow us to determine the role of hyper-luminous (log(L_FIR/Lsun)>13) galaxies in cosmic stellar mass assembly, increase the number of known lensed sources at the peak of cosmic evolution and provide statistical constraints on dark matter halo distribution. With our available ancillary data, we will derive the properties of the massive deflector dark matter haloes out to z~2 and the large-structure they trace, constraining cosmological parameters. The proposed redshift survey will provide the baseline for future detailed studies of the brightest galaxies at the peak of cosmic evolution. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2021-03-31T05:56:34.000 |
| 3890 | 2019.2.00212.S | 0 | Probing the clumpy PDR model in the youngest super star cluster RCW38 | Past theoretical studies of interstellar medium suggest that atomic carbon ([CI]) is confined in the thin layer near the surface of molecular clouds exposed to UV radiation, which is called photo-dissociation regin (PDR). This is called a "plane-parallel" PDR model.However, past [CI] observations revealed that [CI] coexist with CO. Furthermore, our previous [CI] observation with ASTE toward the super star cluster RCW38 found that [CI]/CO column density ratio is high (~0.1) even in the visual extinction is more than 100 mag. These results disagree with the prediction of the plane-parallel PDR model, and suggest "clumpy PDR" model. However, we could not detect clumpy structures of [CI] in our data due to the low-spatial resolution. Our previous high-resolution CO mapping observation of RCW38 with ALMA found clumpy structure of CO having size of ~0.02-0.05 pc. It is expect that, if clumpy PDR model is adopted, [CI] in RCW38 also has clumpy structure and the size of [CI] clump are slightly larger than that of CO clumps. Therefore, we propose [CI] high-angular resolution (2.6" ~ 0.02 pc) mapping observation toward RCW 38 with ALMA in order to probe the clumpy PDR model. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2022-10-21T01:13:02.000 |
| 3891 | 2022.1.01253.S | 54 | H2CO as thermometer for young embedded disks | Although evidence has been piling up that planet formations begins when the disk is still forming within its envelope, the physical conditions in these young disks are still poorly constrained. An important parameter is the disk temperature structure as this determines whether giant planets can form through gravitational instability, and sets the composition of the planet-forming material. Observations of C17O toward 5 embedded disks at 0.5" (70 au) resolution suggest that these younger disks are warmer than more evolved disks and have no CO frozen out in the inner 100 au. In addition, there are hints that the temperature already starts to decrease before the envelope has fully dissipated. To provide more detailed constraints on the temperature structure, we propose observations of multiple H2CO lines toward 10 embedded disks (Class 0, I and I/II) in Taurus and Ophiuchus at 0.25" (35 au) resolution. Observations of CH3CN, N2H+ and SO2 will provide complementary temperature measurements. This program will allow us to construct spatially resolved temperature maps, and will provide the first detailed characterization of the initial conditions for disk evolution and planet formation. | Disks around low-mass stars | Disks and planet formation | 2024-01-27T20:48:03.000 |
| 3892 | 2021.1.00447.S | 102 | The Origin of [C II] and [N II] Emission in High-z Dusty Starbursts (Cycle8) | Far-IR [C II] 158 micron line and the [N II] 122 & 205 micron lines are important ISM cooling transitions that are becoming popular probes for studying high redshift galaxies as a result of the advent of ALMA high frequency performance (Bands 8, 9, & 10). While they are commonly used as tracers of cold gas and SFR, they both arise in relative low density ionized gas in our Galaxy and nearby galaxies and are subject to complications due to variations in radiation field, metallicity, ionization, and gas accretion/ejection. The physical properties gas emitting these FIR lines are even less well understood. We propose to a high resolution, deep imaging study of 3 strongly lensed dusty star forming galaxies at z=2-3 with the requisite spatial information and probe the physical and kinematic properies of the gas emitting the bulk of the [C II] and [N II] lines. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2023-05-02T17:50:03.000 |
| 3893 | 2019.1.01050.S | 8 | Excitation of gas and its effect on star formation suppression in the turbulent Taffy galaxy system | We have shown, through previous ALMA CO observations of the Taffy galaxy system, that its massive turbulent bridge contains a tangled web of high surface-density molecular filaments that should be dynamically unstable to star formation. However, with the exception of a prominent extragalactic HII region and some scattered clusters, many of the filaments are apparently suppressed in star formation. We propose observations of the CO(6-5), and follow-on observations in the CO(3-2) line of the Taffy bridge filaments and the northern Taffy galaxy to spatially map the CO SLED to probe the density and temperature of the molecular gas. We will explore how the gas excitation correlates with the presence or absence of star formation, with regions of high CO velocity dispersion, and with the existence of strong magnetic fields. Our team has strong shock and PDR modeling expertise, and we will use our observations to help refine and develop models of turbulence and shocks which can be applied to many other extragalactic environments, including turbulent gas at higher redshift. | Merging and interacting galaxies | Galaxy evolution | 2022-09-10T00:00:00.000 |
| 3894 | 2015.1.01046.S | 24 | The Molecular ISM and Star Formation Laws of Arp 147 and AM0644-741 | The ``snow plowing'' of >90% of a ring galaxy's ISM into an expanding ring triggers a starburst that persists for >100 Myrs, and subjects the ISM to prolonged damage from the embedded OB stars. This appears to lead to a peculiar ISM state manifested by low molecular fractions, low-density photodissociated HI, and non-SK star formation laws in which H2 and SFR/area appear uncorrelated. To examine the role played by ring age on the ISM we will use ALMA to image 12CO(J=1-0), HCN(J=1-0) and HCO+(J=1-0) emission from the young ring galaxy Arp 147. Together with our UV<-->radio data we will compare its H2 distribution, total and dense H2 fractions, and SFE with local conditions in the ring. We will also see if its CO-based star formation law is peculiar. HCN and HCO+ line emission will enable the derivation of the dense gas star formation law, which holds for ordinary spirals to ULIRGs. We also with to observe the large and evolved ring galaxy AM0644-741, previously observed with the SEST, to refine its CO-based star formatin law, measure its dense gas star formation law, and examine the nature of its ``coiled-rope'' starburst ring from its detailed gas distribution and kinematics. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2017-06-17T00:52:00.000 |
| 3895 | 2017.A.00013.S | 0 | Completing accurate gas-to-dust ratios with [CI] at z~1 | We propose to obtain a modest amount of additional data to complete a largely successful Cycle 4 project. Our aim is to determine the universality of the CI/dust ratio across a representative sample of star-forming galaxies at z=1. In so doing, we will define a calibration of the CI/H2 ratio and compare CI and CO(2-1) as independent tracers of molecular gas mass, assessing the benefits of CI over CO in terms of avoiding systematics related to metallicity dependence and optical thickness. This is a low-risk, high-return proposal since the source properties are well constrained by our existing data. Those data indicate a strong CI/dust correlation with some interesting outliers. Two of the outliers are likely explained by an underestimate of the CI flux due to errors in the grism redshifts used to define the original observations. By re-observing these at the correct frequencies, we will significantly enhance the power of our conclusions, and will fully realise our original science goals on a very short timescale. The results will be influential in calibrating a gas mass tracer applicable to diverse galaxy samples at high redshift, with special relevance to the next ALMA cycle. | Galaxy structure & evolution | Galaxy evolution | 2018-07-05T22:33:47.000 |
| 3896 | 2012.1.00165.S | 0 | The Quest for a robust AGN diagnostic in the (sub-)millimeter domain | We propose to study physical and chemical properties of dense gas tracers towards the central kpc region of the nearby active galaxy, NGC 7469, which hosts a type-1 Seyfert nucleus with a circumnuclear starburst ring of 480 pc in radius. Although HCN/HCO+ and HCN/CO line ratios for nearby AGNs are typically higher than those of non-AGN galaxies in our previous studies, NGC 7469 does not coincide with this result. This inconsistency is likely due to contamination from the surrounding ~1.5" ring like starburst caused by insufficient spatial resolution. Therefore, we have selected a set of key dense gas tracers including HCN, HCO+, SiO, CS and HNCO to probe the physical and chemical properties of the central AGN and starburst at sufficient spatial resolution (0.65"~200 pc at the distance of NGC 7469) to separate these two structures. The proposed molecules can be efficiently observed in Band 3 and 7 thanks to the superb spectroscopic capability of ALMA. With the proposed measurements, we will address the following issues: (1)abundance ratio variations of HCN, HCO+, and CS: Can we see HCN enhancement in the nucleus of NGC 7469 at high resolution observation? (2) Detection of the SiO and HNCO emission in the active nucleus of NGC 7469: Is the central dense gas condensation heated by X-rays or shocks? (3)Searching for vibrationally excited HCN: Does AGN activity promote this emission? (4) Kinematics of the dense molecular gas: Is there an inconsistency of kinematics between CO and HCN? This program will provide us with unique insights that will help answer the questions described above. Also, we will compare the obtained spectrum and line ratios of NGC 7469 with our ALMA Cycle 0 results of NGC 1097, another type-1 Seyfert galaxy with a starburst ring, but much less luminous AGN than NGC 7469. This comparison will help us to study the effect of different AGN luminosity on the surrounding ISM. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy chemistry | Active galaxies | 2016-07-24T14:21:26.000 |
| 3897 | 2021.1.00313.S | 34 | Colliding winds: the detailed structure of the detached shells around R Scl, V644 Sco and DR Ser | Observations of detached shells are one of the few (and possibly only) ways of studying the thermal pulse (TP) phenomenon in asymptotic giant branch (AGB) stars directly. Recent ALMA observations of U Ant have shown spatial and dynamical substructures in the shell as a direct consequence of the hydrodynamical interaction of colliding winds. Archival data of S Sct show the same spatial and dynamical substructures. Observations of R Scl, V644 Sco, and DR Ser do not have sufficient spatial resolution to show spatial substructures in the shells. However, they show the same dynamical splitting of the shells in the spectral information. In order to effectively constrain hydrodynamical models of wind-wind interaction following a TP, it is critical to resolve these substructures. We therefore apply for high-resolution observations of R Scl, V644 Sco, and DR Ser at 0.5". The results will allow us to describe the dynamical evolution of the shells. This does not only have implications for our understanding of the TP cycle, but also for the conditions of wind-ISM interaction and the replenishing of dust from AGB stars to galaxies | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2022-11-08T17:22:38.000 |
| 3898 | 2017.1.00555.S | 13 | Nitrogen chemistry in Eta Carninae | Eta Carniae is one of the most extreme stars in the Universe. This source has underwent massive mass ejections which have formed a complex ejecta around this source: an external Oxygen rich cocoon, with an inner cavity splattered with Nitrogen-rich condensations, and in the innermost regions, the Homunculus nebula result of a 10 solar masses eruption in 1840. As expected from the nucleosysntesys models, this object presents an important Nitrogen enrichment. In addition to this, this enrichment presents a variation as we move further from the star. However, the origin of this variation is not clear. Only recently, the first molecules have been detected towards Eta Carinae, most of the corresponding to N-bearing molecules. We aim to complete this sampling of N-rich species, locate them, and resolve the different kinematical features observed in Single-dish observations. For this purpose, we ask for high angular resolution maps, with a S/N ratio reachable remarkably fast due to the expected strength of the selected lines. | Astrochemistry | ISM and star formation | 2019-02-23T17:46:30.000 |
| 3899 | 2016.1.00434.S | 580 | Unlocking our understanding of submm galaxies with ALMA identifications for >1000 SMGs | We propose ALMA band-7 continuum follow-up observations of an uniformly selected sample of 685 submillimeter sources with S850 > 3.5mJy (4-sigma) from our SCUBA-2 survey of the UKIDSS-UDS. We expect to precisely locate >1000 SMGs with S850 > 1mJy. With this unprecedented large number of SMGs with precise positions, our science goals are to 1) measure the angular correlation function and so derive the halo mass, building the evolutionary links between SMGs and other high-z galaxy populations and their local desendants, 2) test whether the presence of multiple components is a strong function of submm flux, and derive intrinsic number counts, 3) precisely identify the counterparts in other wavelengths and so derive redshift distributions, in particular the form of the high-z tail. With a sample of >1000 ALMA SMGs (~3-10 times larger than that of previously samples), we will measure the multi-wavelength properties of the population, redshift distribution and most critically their clustering, to conclusively test whether their likely present-day descendants are massive ellipticals or more typical galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2017-12-21T18:43:21.000 |
| 3900 | 2016.1.01340.S | 95 | ALMA as a sensitive probe of the stellar IMF and star-formation mode across the cosmic time | We request ALMA observing time in order to built on our success of using it as a powerful new probe of the stellar Initial Mass Function (IMF) in dust-enshrouded star-forming systems in the distant Universe. Our recent results based on ALMA observations of the rotational transitions of the isotopologues 12CO, 13CO, C18O demonstrate the sensitivity of such data on the underlying stellar IMF, and the same data also show a marked sensitivity on the assumed star formation (SF) mode (quiescent versus starburst) of galaxies. This opens up another, unexpected, line of exploration in which a fundamental issue such as the SF mode of galaxies in the Early Universe can be addressed in a new way, one depending on Stellar Physics. Our current request for ALMA observations seeks to expand the scope of our original investigations to include both the stellar IMF and the SF mode in dust-obscured star-forming galaxies across cosmic epoch. | Starburst galaxies | Active galaxies | 2018-03-22T21:20:59.000 |
| 3901 | 2013.A.00014.S | 2 | The most distant dusty starburst: 13 Gyr or bust | Only a handful of SMGs are known at z>4, most of them lensed. Using ALMA we set out to measure the redshifts of a unique sample selected from our wide Herschel imaging. The galaxies were selected on the basis of their faintness (ergo they are largely unlensed) and extreme redness (ergo they are rare and very distant). Their properties have been further constrained through SCUBA2 and LABOCA imaging, making it a remarkably robust sample, all with z>4. Recent ALMA 3-mm spectral scans have determined CO redshifts for 3 of 4 targets; for our final target - our reddest, nicknamed "Great Red Hope" - we see weak emission lines corresponding to 12CO(7-6) and CI(2-1). These suggest that this is the most distant dusty starburst known. With no plausible lens and L(bol) ~ 10^14 L(sun), this object poses a genuine problem for accepted models of galaxy and structure formation. Confirming that such an extreme starburst has formed only 740 Myr after the Big Bang is of profound and urgent interest. Here, we propose to confirm its redshift unambiguously via deeper observations of 12CO(7-6) and CI(2-1), as well as 12CO(6-5), which requires a total of 2 hr. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2015-08-13T18:31:19.000 |
| 3902 | 2021.1.00927.S | 356 | The fall and rise of Betelgeuse: diving in its ejecta with ACA | One year ago the visual dimming of Betelgeuse caused a cascade of public news, following the suggestion of an imminent core-collapse. Other hypotheses formulated to explain this extraordinary event were the formation of large cold spots on the stellar photosphere, or an increased extinction along the line of sight. Betelgeuse may have undergone an increased mass-loss episode that favours dust grain formation, consistently with the erratic stellar activity of evolved massive stars. We propose a monitoring programme with ACA in Bands 3, 6 and 7, to test the role of dust in the recent visual dimming and to perform an unprecedented study of the dust properties and formation cycle. We request calibration-limited observations (with photometric uncertainty of 5%) to derive light curves at five different frequencies and, additionally, spectral indices to disentangle different emission mechanisms contributing to the sub-mm wavelengths. With these observations we will gain a rare insight into dust processes and mass-loss in massive stars. | Hypergiants | Stars and stellar evolution | 2023-08-08T10:52:59.000 |
| 3903 | 2023.1.00415.S | 0 | G351 N2H+ dense gas kinematics | Observed as part of the ALMA-IMF Large Program, G351.776-0.527 (at a Gaia d = 2 kpc) is a massive filamentary IRDC containing a compact protocluster. Current estimates from Spitzer surveys and single-dish submm data show that G351 has a far lower star formation (SF) efficiency per free fall time than "universal" SF relations measured in nearby clouds (d < 1.4 kpc), even with stringent completeness corrections. ALMA-IMF targeted the protocluster, but did not cover the extended filament where Spitzer measured low SF rates. We propose to extend the N2H+ (1-0) Band 3 map over the G351 filament area. These data will complete the picture of how the G351 protocluster is connected (or not) to the maternal filament. They will measure velocity gradients down to scales of ~ 0.02 pc. They will reveal the dense gas kinematics on these scales for the first time and allow for the robust comparison with other massive protocluster forming filaments. Our submitted JWST proposal will pinpoint where the protostars are, and together these data, and the dense continuum cores, will provide a complete picture of why G351 is underperforming today in terms of its SF rate. | High-mass star formation | ISM and star formation | 2024-12-19T20:02:46.000 |
| 3904 | 2021.2.00088.S | 18 | ACA B7 and B8 Mosaic of a Planck selected cluster lensed dusty protocluster at z = 2.7 | Our understanding of the cold interstellar medium and extended emission towards protoclusters at high-z is still limited, particularly how wide-spread star formation can be and determining the molecular gas mass in cluster environments. Therefore we request one of the largest ACA B7 and B8 mosaics around a distant, dusty protocluster to-date. We aim to trace the redshifted thermal dust emission from the core field of a sub-mm all-sky Planck-selected, cluster-lensed-protocluster at z=2.66, with IR luminosity log(LIR)> 14 Lsun. By mapping the entire strong lensing magnification map we will characterize the rise in rest-frame dust emission from all counterparts within a physical area of about 650 sq. kpc. Matched with wide-field imaging of low-J CO from ALMA/B3, it will be possible to estimate robust global molecular gas mass and star formation rate surface density maps to examine the distribution of gas/dust and the typical depletion time for this massive, lensed DSFG protocluster. This will showcase the ALMA ACA capability to mosaic wide-frequency ranges to examine protocluster environments in the early Universe. | Sub-mm Galaxies (SMG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 3905 | 2017.1.01057.S | 0 | Investigating CO Emission Associated with the Luminous Blue Variable AG Car | Luminous Blue Variable stars (LBVs) are a highly luminous (~10^6 Lsun), unstable phase in the evolution of massive stars. AG Car is regarded as a prototypical LBV and is one of the best studied objects in its class. Both CO 1-0 and 2-1 have been detected in single dish observations of AG Car. The emission is thought to originate from the circumstellar environment of AG Car, either from a cool extended circumstellar envelope or a disk close to the star. We are requesting high spatial resolution (25 mas) observations of AG Car to determine if the CO emission associated with this object is due to a disk close to the source. Detecting molecular emission from circumstellar disk around AG Car would be first of its kind detection for an LBV. The discovery of a massive disk around this object would indicate that equatorial mass loss due to stellar rotation plays a significant part in the total mass loss of AG car. This result would demonstrate an important difference between fast and slow rotating LBVs. | Evolved stars - Shaping/physical structure, Luminous Blue Variables (LBV) | Stars and stellar evolution | 2018-12-28T02:50:19.000 |
| 3906 | 2019.2.00093.S | 491 | Newly discovered hot core precursors: early warm-up phase and diversity | During star formation a large variety of molecules including complex organic molecules (COMs) emerge, however, their origin and the molecular diversity among hot cores is poorly understood. Here we ask to use unbiased spectral surveys to explore the molecular composition (and diversity) of six hot core precursors discovered in our previous project, SPARKS. They are excellent laboratories to study the early warm-up phase chemistry because they exhibit particularly massive envelopes dominated by cold gas, and a heated inner envelope with T~100K at <1500au. Sincs they are in monolithic collapse, we could obtain a high sensitivity, unprecedentedly broad band spectral survey between 2mm and 0.8mm with APEX (16"-39"). We identified >40 molecules (+isotopologues) including COMs, some of them also in the cold gas. It is indispensable to complete our unique dataset in the 3mm window with ACA (15") to (1) constrain the physical conditions in the cold gas with low-J transitions of simple molecules, and COMs; (2) confirm tentative detections for several molecules; (3) search for rare COMs and heavier carbon chain molecules. Comparing to chemical models we will explore their chemical evolution. | High-mass star formation, Astrochemistry | ISM and star formation | 2021-06-09T21:04:47.000 |
| 3907 | 2017.1.01368.S | 55 | MAGNIFIED VIEWS OF THE MOLECULAR GAS OF THE z=1.51 LENSED AGN HS 0810+2554 | Recent observations of the z = 1.51 lensed AGN HS 0810+2554 have revealed a wide-angle relativistic outflow of X-ray absorbing ionized material with velocities ranging between 0.1 and 0.4c. UV spectroscopic observations with VLT/UVES indicate that the UV absorbing material in this object is outflowing at v_UV~0.065c. VLA observations reveal extended radio emission with a size of ~90pc. Our primary goals with the proposed ALMA observations are to, (a) spatially resolve the mm emission and infer the physical conditions of the molecular gas at these scales. The detection of extended mm on scales ~90pc will confirm a model in which the weak radio emission of radio quiet quasars is produced by disk winds colliding with the NLR gas clouds. (b) search for the molecular outflow with CO(2->1) and CO(3->2) ALMA observations. The proposed observations will show whether or not a small and large scale energy-conserving outflow is present in a high redshift quasar near the peak of AGN activity. The detection of a momentum boost of the large scale molecular outflow of HS0810 at the predicted level will also confirm magnetic driving of the relativistic wind of HS0810. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-01-30T18:07:22.000 |
| 3908 | 2015.1.00813.S | 82 | Linking the ISM to Star Formation During an Epoch of Active Evolution in Galaxy Clusters | Recent observations have uncovered an epoch of star formation (SF) and AGN activity in galaxy clusters at z=1-2, providing an unprecedented opportunity to examine galaxies in extreme environments prior to the passive evolution seen in local clusters. We propose to quantify the gas properties in 129 cluster galaxies during this pivotal epoch through submillimeter continuum emission. From this we will measure the total mass of the ISM and relate this quantity-which is dominated by molecular hydrogen in high redshift galaxies-to ongoing SF and AGN activity as a function of environment. Combined with our existing deep infrared observations and ancillary data, we can then derive the star formation efficiencies (SFE), thereby constraining the mode(s) of star formation in a statistical sample of active cluster galaxies. We will additionally quantify the gas fraction in cluster galaxies, providing a necessary complement to ongoing analyses in field galaxies. This modest 8 hour proposal will provide the first statistical sample of cluster galaxies with measured ISM properties at z>1, from which we will paint a clearer picture of the relationship between environment and galaxy evolution. | Starbursts, star formation, Galaxy groups and clusters | Active galaxies | 2017-09-01T17:30:43.000 |
| 3909 | 2013.1.00760.S | 2 | Measuring the Most Energetic Event in the Universe | Galaxy clusters are the largest gravitationally-bound objects in the Universe and, according to the hierarchical picture of structure formation, are the most recent to form. A crucial aspect of their formation is through mergers, which violently dissipate most of their kinetic energy in shocks. The merger in 1E0657-56 -- a.k.a. "the Bullet Cluster" -- is one of the cleanest astrophysical labs for shock physics and may be the single most energetic event in the visible Universe since the Big Bang itself. The Bullet Cluster provides direct evidence that clusters are dominated by cold dark matter through the large spatial s eparations between the gas and lensing peaks. We propose to use ALMA+ACA Band 3 observations to provide the first sensitive (~7.6 uJy/bm), high-resolution (<8") Sunyaev-Zel'dovich effect measurement of the shock front in the Bullet Cluster. We will jointly model the ALMA measurements of the shock with deep X-ray data from the Chandra and NuSTAR X-ray telescopes, and compare these measurements to existing arcminute-resolution measurements to place more direct constraints on the shock energetics and better infer the line of sight distribution of the gas. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2016-03-23T16:01:12.000 |
| 3910 | 2016.1.00595.S | 41 | Dissecting the circumstellar disk around the B-type protostar IRAS20126+4104 | The existence of disk+outflow systems around early-type stars has been invoked by theorists to overcome the powerful radiation pressure by the star and allow the accretion onto the star to proceed up to 140Msun. Despite their importance, only recently bona-fide disk candidates have been detected around B-type (>8Msun) protostars. IRAS20126+4104 is by far the best of these. Both the close distance (1.64kpc) and the well studied disk+outflow system make this the ideal target for a high-resolution study with ALMA. With the proposed observations we will for the first time establish the rotation curve and disk physical parameters (temperature, column density) as a function of radius. Our observations will be a breakthrough, as little is known on the nature of the disks around B-type stars because the resolution attainable before ALMA was insufficient to properly resolve them. In particular, we will obttain the following: calculate the Toomre Q parameter as a function of radius and assess whether the disk is stable; compute the accretion rate through the disk onto the star; establish the presence of gaps and/or local instabilities, possibly induced by stellar companions. | Disks around high-mass stars | Disks and planet formation | 2018-08-02T06:59:54.000 |
| 3911 | 2021.A.00034.S | 0 | A Stellar Occultation by Titan: Contemporaneous Sub-mm and Optical Wind Mapping | On September 5th 2022, Saturn's moon Titan will be subject to a rare stellar occultation event, during which the center of Titan's shadow will pass almost directly over Mauna Kea. This will provide an exceptional opportunity to perform high-cadence photometry of the refracted light around Titan's limb, using some of the most powerful optical telescopes on Earth. These refracted light measurements are extremely sensitive to the zonal wind speeds in Titan's atmosphere [1]. Previous stellar occultation measurements, however, have shown very different zonal wind speeds as a function of latitude compared with those obtained recently using ALMA Doppler-shift data [5,9]. We propose to take advantage of this unique opportunity to perform contemporaneous (optical) occultation and (sub-mm) Doppler wind-mapping observations to help resolve the cause of this discrepancy and thus improve our understanding of Titan's complex global circulation and climate. | Solar system - Planetary atmospheres | Solar system | 2024-03-13T14:47:52.000 |
| 3912 | 2017.1.00428.L | 1657 | ALPINE: The ALMA Large Program to INvestigate CII at Early times | ALPINE will measure C+ and FIR continuum emission for a sample of 122 main sequence star-forming galaxies spectroscopically confirmed at 4~10 M/yr and 9 | Lyman Break Galaxies (LBG), Gamma Ray Bursts (GRB) | Galaxy evolution | 2019-05-31T11:27:06.000 |
| 3913 | 2016.1.00296.S | 208 | Molecular tori around massive black holes | The unification paradigm of Active Galactic Nuclei (AGN) assumes that a molecular torus, at 1-10pc from the center, is obscuring the broad line region and the accretion disk around the black hole in type 2 nuclei. Recently, we have been able with ALMA to detect for the first time with CO(6-5) the molecular torus of 10pc diameter in the Seyfert 2 galaxy NGC 1068 (Garcia-Burillo et al 2016). Surprisingly, the torus is tilted, warped, and its kinematics is dominated by turbulence and non-circular motions. We propose here to search for molecular tori in 7 other AGN targets, that we have already observed with ALMA at 30-100pc resolution. We propose to observe the CO(3-2) at ~4pc resolution, with 0.06'' beam, to explore many other different conditions in terms of AGN or star formation power, taken in different evolution cycles. We will then be able to start to constrain the evolutionary phases of the molecular torus, and relate its morphology and kinematics to the AGN accretion rate, to the gas flow that we will measure from the gravity torques, and when there is a molecular outflow at large scale, track its origin at the level of the torus. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-08-19T07:09:10.000 |
| 3914 | 2016.1.00831.S | 229 | ALENS: The ALMA lensing survey of sub-M* galaxies at z~1-3 | Building on our successful CO project with PdBI, we propose ALMA CO observations of 18 lensed star-forming galaxies at z~1-3 to construct the first significant sample of robust molecular gas mass measurements of the more numerous, typical, i.e. sub-M*, galaxies with stellar masses 91. We will also test the universality of star formation in galaxies, as reflected by the relation between IR and CO luminosities, from the exploration of the enlarged parameter space. Finally, we will compare over the sub-M* domain the direct measure of the molecular gas mass from CO with the often-used indirect method probing the dust mass. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2018-03-21T17:12:39.000 |
| 3915 | 2013.1.00843.S | 3 | Sunyaev-Zeldovich mapping of an extreme cool core in the galaxy cluster RXJ1504-02 | The massive, relaxed galaxy cluster RXJ1504 hosts one of the most extreme X-ray luminous cool cores. Cool cores are a balancing act of several physical phenomena -- the radiative cooling is offset by some heating mechanism(s) with a feedback loop to keep the cluster stable. Cooling depends on the gas spatial structure, while heat can have several sources, whose efficiency depends on poorly understood physical properties of the intracluster plasma. We recently obtained a Sunyaev-Zeldovich map of the RXJ1504 core with CARMA at 12" and 44" resolutions to study the distribution of its gas pressure. While there is large-scale agreement, we found that the peak of the SZ signal does not coincide with the X-ray peak, but instead sits at the tip of a subtle sloshing gas filament. It is very difficult to generate small-scale pressure nonuniformities in a non-merging cluster; something significant must be missing from our understanding of the cool core physics. Several interesting possibilities exist. We propose to resolve the structure of our 20" SZ peak with ALMA's 4.5" beam in order to elucidate its possible nature. This would be the first high-resolution SZ study of a cluster cool core. | Galaxy Clusters | Cosmology | 2016-03-20T13:11:46.000 |
| 3916 | 2011.0.00497.S | 0 | Eta Carinae: Continuum and H and He recombination lines v1.3 | The objective of this proposal is to observe the region surrounding the peculiar star Eta Carinae and its binary companion, in the H recombination lines H40α (99 GHz), H30α (232 GHz), H28α (284 GHz), and H21α (662 GHz), as well as in the continuum at the same frequencies. The emission arises from an elongated structure seen at cm wavelengths that extends for several arcsec and can be resolved with ALMA, even in the initial phase. Single dish observations, previously obtained with SEST at 100 and 230 GHz, showed that the continuum flux density increases with frequency, as expected from optically thick plasma. The H40α and H30α recombination lines, also observed with SEST, present strong maser emission, characteristic of plasma with densities higher than 10^7 cm^-3. ALMA is the perfect tool to study the density distribution of the material that surrounds the binary system forming the disk-like structure; in its early science configuration it will allow to compare, with the same spatial resolution, the structure at millimeter wavelengths with what was obtained with ATCA at cm wavelengths. Observations at different millimeter wavelengths will allow the determination of the volume density of ionized matter, by comparing the emission as a function of the distance to the binary system. The high frequency H21α line will be observed for the first time. | Luminous Blue Variables (LBV), Evolved stars: Shaping/physical structure | Stars and stellar evolution | 2014-02-04T15:49:00.000 |
| 3917 | 2023.1.01372.S | 0 | Probing the formation pathway of a Fast Radio Burst: CO 3-2 observations towards FRB190520 | Fast radio bursts (FRBs) are millisecond-long radio flashes of unidentified extragalactic origin. As these coherent and energetic pulses travel through space, they probe the intervening medium and thus, are proposed as powerful tools for cosmology. While the origin of FRBs remains mysterious, the most popular scenarios link them to highly magnetized neutron stars known as magnetars. One recently discovered FRB, FRB190520, promises a unique laboratory to test the formation channels of repeating FRBs. This FRB was located in a dwarf galaxy at z=0.241 with high star formation rate and co-located with a persistent radio source of unknown origin. Its Monitoring has revealed that the FRB resides in a complex magneto-dense environment. We propose CO spectroscopy to study the properties of the local environment to the FRB, therefore constraining their yet unknown progenitor. We will use the CO 3-2 line as a diagnostic of the molecular gas mass and dynamics of the galaxy hosting FRB190520 to understand whether the progenitor of the FRB arises from a violent event or whether there is a high-velocity gas component which could be indicative of the presence of an Active Galactic Nucleus. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-04-02T19:13:42.000 |
| 3918 | 2015.1.00989.S | 61 | Does Cold Gas Fuel Almost All AGNs? | The growth of supermassive black holes and their impact on their host galaxies depends on whether they predominantly accrete hot or cold gas. The most powerful AGNs are likely fueled by cold gas, but the fuel source for most AGNs is controversial and may differ between types. Our work on an unbiased survey of active black holes in early-type galaxies shows that cold gas is present in almost all active galaxies, suggesting that cold gas is a universal fuel source, but we lack direct observational evidence. In this program we will measure the cold gas mass within the central 50 pc of a representative subsample of these galaxies to determine whether it is correlated with the AGN luminosity. | Active Galactic Nuclei (AGN)/Quasars (QSO), Early-type galaxies | Active galaxies | 2017-08-10T00:35:23.000 |
| 3919 | 2015.1.01019.S | 96 | Star formation efficiency in the outer filament of Centaurus A | NGC 5128 (Centaurus A) is the most nearby powerful AGN, widely studied at all wavelengths. Molecular gas is found at a distance of ~20 kpc from the galaxy centre, associated to HI shells, via CO line detection at SEST. The molecular gas lies inside some FIR and UV bright star-forming filaments that are observed in the direction of the radio jets. We propose here to use ALMA (band 3 CO(1-0) large scale mapping) to study jet-induced star-formation in the northern filaments of Cen A. We want to determine whether the star formation efficiency changes along the filaments and look for morphologically-driven star formation evidence along the jets, as suggested by our recent comparison of archival FIR/FUV/CO at a scale of 800 pc (44"). The spatial resolution of ALMA (1.2"~20 pc) is ideal to detect GMC, without resolving them, and derive the star formation efficiency at small scale. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2017-07-19T14:39:00.000 |
| 3920 | 2017.1.00108.S | 175 | In Search of Cometary H2S in Low-Mass Protostars | Hydrogen sulfide (H2S) is the most abundant volatile sulfur-bearing molecule in the coma of 67P/Churyumov-Gerasimenko, as measured by the ROSINA instrument aboard Rosetta (Calmonte et al. 2016). The initial comparison of ROSINA data and ALMA observations towards the low-mass protostar IRAS16293-2422 indicates that for 67P there is much more H2S present, while for IRAS 16293-2422 more OCS is available. This suggests that our Solar System may have been born in a warmer, CO-poor environment limiting the production of OCS. The proposed observations intend on verifying this hypothesis by constraining the H2S/OCS ratio for three low-mass star-forming regions: IRAS16293-2422, R CrA IRS7B and NGC1333 IRAS4A. This will allow the innate protosolar disk, as traced by 67P, to be compared with a pilot sample of other young disks to see if it was atypically warmer than other systems analogous in mass. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-07-02T11:29:46.000 |
| 3921 | 2013.1.00639.S | 13 | Spatial Distribution of physical and chemical properties for dense clumps at different evolutionary stages in supergiant HII region NGC604 | We propose to obtain high-resolution 13CO(1-0), C18O(1-0), CS(2-1), CH3OH and 12CO(3-2) maps of the supergiant HII region (GHR) NGC604 in M33 to study the physical and chemical properties of molecular gas at different evolutionary stages in the giant HII region. They are tracers of total gas, dense clump, and moderately dense clump, respectively. GHRs can be "mini-starburst" and provide us with an ideal environment to understand the clustered OB star formation. Our previous studies (~ a few 10-100 pc) suggest that giant molecular cloud complex of the NGC604 is a unique laboratory for the different, especially, early and intermediate stages along star formation. The next questions are their internal structure - dense molecular gas in a few pc, "clump". Our requested spatial and velocity resolutions (1."3 or 5 pc and 0.7 km/s), and sensitivity (0.2 K at 100 GHz) can detect a typical clumps, i.e., 1000 Mo. We can simultaneously detect massive dust clump with mass of 250Mo by 0.85mm continuum emission and several O9 stars by 3mm continuum emission. The primary goal of this proposal is to obtain a clump-scale view of dense molecular medium in the NGC 604 complex. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2016-12-29T23:57:19.000 |
| 3922 | 2019.1.01612.S | 44 | CONfirm: probing the most deeply obscured galaxies in the local Universe | It has been known for a while that some (U)LIRGs host extremely compact obscured nuclei (CONs) that are driven by either an active galactic nucleus or an extreme nuclear starburst. Preliminary results from our recent survey CON-quest indicate that these objects are more common, and thus important, than previously thought (as many as a quarter of all LIRGs may host a CON). We therefore propose high-resolution (0.02-0.025'' and 0.04-0.045'') band 6 and 3 observations of the continuum and the remarkably luminous vibrationally excited HCN (HCN-VIB) and HC3N emission in four newly discovered CONs. These vibrational lines serve as proxies for extremely high mid-IR surface brightnesses, and the proposed observations will allow us to resolve the hot nuclei and probe their morphologies, dynamics, and luminosity densities. With these data, we will be able to determine exactly how obscured CONs are, and put strong constraints on the nature of their primary power sources, potentially revealing a significant population of deeply hidden AGN. | Galactic centres/nuclei, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2023-01-20T06:24:04.000 |
| 3923 | 2013.1.00889.S | 20 | Chemical Variation between a Spiral Arm and a Bar in M83 | Establishing physical meanings of GMC-scale chemical compositions will improve our understanding of GMC evolution in a spiral arm as well as in extreme physical environments such as AGNs and starbursts. Many previous studies have shown that strong shocks occur in bar regions of spiral galaxies and suppress star forming activities. Therefore, the GMC-scale chemcail compositions are expected to be different between a spiral arm and a bar. In order to explore how the kpc-scale gas dynamics and star formation activities affect the GMC-scale chemical compsositions, we propose multi-line imaging observations toward a spiral arm and a bar in M83 with ALMA in the 3 mm band. From this observation, we would like to reveal the averaged GMC-scale chemical compositions in the spiral arm and the bar. Furthermore, the origin of the possible chemical difference is explored on the distributions of molecules in the two regions. This observation will provide us with an important and fundamental base for interpreting the physical meaning of the chemical composition in extranal galaxies. | Galaxy chemistry | Galaxy evolution | 2016-08-05T16:26:18.000 |
| 3924 | 2015.1.00392.S | 104 | Completing the disk census in Taurus | We propose to observe 68 single and multiple young stellar systems in Taurus to answer how protoplanetary disk mass depends on both stellar mass and multiplicity. While previous surveys show a correlation between stellar and disk mass, most sources below spectral type M3 are undetected and it is not known if the same dependence holds down to the stellar mass limit. Our Cycle 0 observations of wide binaries detected disk masses down to 10-4 MSun and revealed a range of disk mass distributions. ALMAs sensitivity and resolution enables us to observe a complete sample to tackle this issue; these observations have a sensitivity level 10 times better than previous large surveys of this region. The selected sample provides complete coverage of all stars in the disk-only phase by targeting undetected single stars and undetected or unresolved multiple systems. Using these Band 6 continuum fluxes to measure outer disk mass, combined with the wealth of ancillary data on Taurus, we will establish the influence of stellar mass and multiplicity on the potential for planet formation. This is a re-submission of a grade B, Cycle 2 proposal for which no data have yet been taken. | Disks around low-mass stars | Disks and planet formation | 2018-05-12T16:23:45.000 |
| 3925 | 2016.1.01532.S | 1 | Unveiling the Nature of Small-Scale Energy Release Events in the Low Solar Atmosphere | We propose to investigate small-scale energy release events in the solar chromosphere near sunspots. Such events are implicated in atmospheric heating, and the basic processes are thought to be the same as for larger flaring events. The penumbral region around sunspots is chosen because such events are common there in a variety of forms, making it certain that at least dozens of such events will be seen in 1 h of observation, and the dark sunspot provides a landmark that allows accurate co-pointing of ALMA with other high-resolution instruments with restricted fields of view. ALMA solar observations open a new wavelength regime at high temporal and spatial resolution, with which to discover new phenomena as well as provide a new view of known phenomena. Comparing timing, dynamics, and diagnostics of temperature and density of these events from ALMA with those from other solar instruments will elucidate the origin of the small-scale energy release and its consequences for particle energization and heating over this important part of the solar atmosphere. | The Sun, Main sequence stars | Sun | 2018-08-17T00:00:00.000 |
| 3926 | 2022.A.00010.T | 27 | Submillimeter Observations of a Luminous Fast Blue Optical Transient | Luminous fast blue optical transients (LFBOTs) are a new class of cosmic explosions powered by active compact objects (magnetars or accreting black holes), the first new such class discovered in over a decade. Until recently, the only LFBOT with detailed multiwavelength observations was AT2018cow. AT2022tsd is the first LFBOT discovered in two years, and only the third LFBOT discovered in real time. Earlier this week, NOEMA obtained a strong detection at 280 GHz (350 GHz in the rest-frame), making this the most luminous LFBOT at submillimeter wavelengths. Submillimeter observations offer a unique diagnostic of energetic blastwaves. There is an extensive multiwavelength campaign to observe AT2022tsd across the electromagnetic spectrum, including Swift/XRT and 10-m class optical telescopes. To complement observations at lower frequencies (5-300 GHz), we request ALMA observations in Bands 6-8. The proposed ALMA observations, combined with decimeter to centimeter observations and Swift X-ray monitoring, will enable measurements of the circum-explosion density, the blastwave energy, and the microphysics of this most unusual shock. | Transients | Stars and stellar evolution | 2023-06-22T16:05:00.000 |
| 3927 | 2018.1.01309.S | 37 | Tracking the 8 au orbit of a circumplanetary disk recently detected in ALMA continuum and CO kinematics | Using ALMA, we detected a circumplanetary disk candidate to the Herbig star HD100546: a 1.3 mm continuum compact emission at 50 mas separation from the central star. The 5-sigma detection falls in the middle of this protoplanetary transition disk's cavity at 8 au separation --comparable to Jupiter's orbit--. Our discovery is supported by the CO gas kinematics of the cavity whose velocity map is distorted at the source location. If co-planar, the companion is on a ~14 yr orbit. Additionally, these observations resolve the inner disk around the Herbig star. Here, we ask for a second epoch of ALMA Band 6 data to follow up on this direct detection of a circumplanetary disk inside a protoplanetary gap. The ALMA data were acquired on Sept. 2017, at the end of Cycle 4: a second epoch during Cycle 6 would not only probe for orbital motion (45 degrees rotation) but also reveal the non-Keplerian intra-cavity dynamics. | Disks around high-mass stars, Exo-planets | Disks and planet formation | 2020-10-29T20:20:22.000 |
| 3928 | 2022.1.00181.S | 35 | Understanding star formation in the swept-up ring around the RCW 36 HII region | When feedback from high-mass stars disperses a cloud, it can simultaneously also create dense rings of swept-up gas that can form stars. Currently it is unclear which physical processes regulate the star formation activity in these rings and how this affects the star formation activity and outcome in these rings. Here we propose to map the full swept-up ring around the RCW 36 HII region with 7m compact array observations that cover dust continuum, protostellar outflow, temperature and dense gas tracers. The observations will determine the triggered star formation activity of the full ring and evaluate its relative contribution to the total cluster. Additionally, the different observed lines and archival data will allow to study the different support terms (thermal, turbulent and magnetic) and inflow in the ring and cores to propose a comprehensive scenario to explain the observed star formation activity. Lastly, the proposed observations can support archival data to probe the relative magnetic field orientations from the cloud down to the 0.03 pc scale. | HII regions | ISM and star formation | 2024-06-22T17:55:24.000 |
| 3929 | 2019.1.01069.S | 2 | Using Hydrogen Recombination-line Masers to Trace Disk and Wind Dynamics in MWC 349A | Disk winds are thought to play a critical role in star birth. As winds extract excess angular momentum from accretion disks, matter in the disk can be transported inward to the star to fuel mass growth. However, the observational evidence of wind carrying angular momentum has been very limited. We propose ALMA observations of a rare hydrogen recombination-line maser object MWC349A. The high signal-to-noise ratios made possible by the maser emission process and high spectral dynamic range of ALMA allow us to constrain the relative astrometry of the maser spots to 0.1 milli-arcsecond precision. By improving relative astrometry by one order of magnitude over the previous SMA and PdBI studies, this project will determine how angular momentum is transfered to the wind within a radius of 25 AU, and inform theoretical models of jets and outflows. | Outflows, jets and ionized winds | ISM and star formation | 2022-10-19T14:24:03.000 |
| 3930 | 2022.1.01124.S | 23 | How common are extreme molecular haloes around z~2 quasars? | Cicone et al. (2021) reported the discovery of a giant CO(3-2)-line emitting halo extending out to r~200 kpc from a quasar at z~2 selected to have known kpc scale outflow. Such halo was resolved out by ALMA and could only be revealed through fairly deep ACA observations. This molecular circumgalactic medium reservoir may embed a massive amount of molecular gas, and it does not appear to be associated with an overdensity of optical, infrared or sub-millimeter emitters around the quasar. We propose to expand the relevance of this discovery for the field of galaxy formation and evolution by extending the search for massive >100kpc-size CO haloes in additional five z~2 AGN, hosting a wide range of kpc scale outflow properties, using similar deep ACA CO(3-2) observations. The goals of this pilot study are: 1) a first assessment of how common these massive H2 haloes are at z~2; 2) understand the relevance of AGN outflows in the formation of this cold phase of the CGM. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2024-11-03T14:15:11.000 |
| 3931 | 2015.1.00834.S | 10 | Resolving a main-sequence star-forming galaxy merger at redshift 6 | In ALMA cycle 2 we observed z=6 UV-luminous Lyman Break Galaxies, detecting them in both the [CII]line and dust continuum. Our resultsrepresent the first unambiguous detections of the [CII]cooling linein galaxies other than luminous quasars in the epoch of reionization.For one target, we discovered a merger of two galaxies with a projectedseparation of only 0.3'' (2 kpc) and 250 km/s in velocity. This pairis particularly interesting because the component with the lowerlinewidth and lower [CII]luminosity is closer to the rest-frame UVcentroid than the presumably more massive component. Our cycle 2observations were at a resolution of 0.5'' such that the two galaxiesare hardly resolved. Here we request higher resolution observations inthe [CII]line and dust continuum to (i) spatially separate the dustemission from the two galaxies; (ii) separate the [CII]emission inthe velocity overlap region; (iii) derive sizes and shapes for the[CII]emission of each galaxy. With these observations we willdetermine dynamical masses of the galaxies, derive [CII]/FIR ratiosfor each galaxy independently and relate the obscured/unobscured starformation ratios to physical conditions. | Lyman Break Galaxies (LBG), Galaxy structure &evolution | Galaxy evolution | 2017-11-15T23:11:48.000 |
| 3932 | 2016.1.00030.S | 3 | Energy evaluation of micro- and nano-flaring heating events in solar active regions | Reconnection events in nanoflare energy range are a candidate for the heating of the corona in active regions. The number distribution of reconnection events as a function of energy is essential to evaluate the importance of nanoflares in the heating. ALMA observations would provide a new capability for newly exploring the released energy of reconnection events in the energy range around 10^23-10^24 ergs. Transient heating of the plasma at the upper chromosphere caused by reconnection events is observed as the transient increase in brightness temperature. The time series of the ALMA measurements, coordinated with Hinode and IRIS observations, are investigated to establish a new method for estimating the amount of the energy released by each of small reconnection events. | The Sun | Sun | 2018-07-07T00:00:00.000 |
| 3933 | 2013.1.00566.S | 14 | Bulge Formation in Star-forming Galaxies at z>2 | We propose to conduct 0¥arcsec.16 resolution dust continuum (350GHz) imagings of 14 star-forming galaxies at z>2 which has been identified by narrow-band surveys with Subaru Telescope in SXDF-CANDELS field. The targets are very suitable for ALMA cycle-2 capabilities because the feasibility is carefully estimated from their MIPS 24um and AzTEC 1.1mm data. Their rest-frame UV/optical images have already been obtained by WFC3/ACS on HST. ALMA is the only instrument which can provide us with such high-resolution submm maps. Combining the rest-frame far-infrared images by ALMA with the rest-frame UV images by HST, we aim to resolve the internal distribution of star formation activities including both dust obscured and unobscured ones and identify the mode of star formation such as ``burstiness'' and ``dustiness'' in each resolved region or clump for the first time. Our question is, ``where are new stars being formed within high-redshift galaxies?''. This could be closely related to formation of bulges and disks. With the extensive high-resolution data-set, we will confirm the epoch of bulge formation and address this issue. | Starburst galaxies | Active galaxies | 2016-11-25T04:53:53.000 |
| 3934 | 2021.1.01065.S | 105 | The First Ever Low Metallicity PDR Benchmark: Revealing the CO-Dark H2 | We propose ALMA observations of CO and [CI] emission lines in a low metallicity PDR that is the target of upcoming JWST observations. In Cycle 1, an approved GO program will observe the N13 PDR in the Small Magellanic Cloud using the NIRSpec and MIRI intergral field units with resolution that will locate the transitions from ionized to atomic to molecular hydrogen (H+/H/H2) and map the physical state of the gas and dust. At low metallicity, a key prediction of PDR models is that the transition from atomic carbon to carbon monoxide (C/CO) will occur deeper in the PDR compared to higher metallicity regions, due to decreased dust shielding. This prediction is central to explaining the prevalence of ``CO-Dark H2'' at low metallicities, but it has never been directly tested due to the lack of observations that can resolve both the H/H2 and C/CO transition of a PDR in a low metallicity environment. This is now possible for the first time with the pairing of ALMA and JWST. These proposed observations will be critical tests for CO and [CI] as molecular gas tracers at low metallicity and provide the first resolved benchmark for low metallicity PDR models. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2025-11-14T23:53:45.000 |
| 3935 | 2015.1.01339.S | 315 | Identifying the transition phase of the clump mass function toward the IMF | Stars form in dense, dusty clumps and the observed similarity between their mass distribution and the IMF supports the idea that clumps may fragment into sub-structures ("cores" or fragments) which then form stars or even clusters of stars. However, the transition from the observed "clump mass function" (CMF) to the IMF is still poorly understood theoretically, and not well constrained observationally. We propose to map with ALMA+ACA the structure of 70 clumps found in the Hi-GAL l=224 field, and already observed with the Mopra telescope, in order to study the ultimate level of fragmentation prior to collapse of an individual fragment into a proto-star. We want to compare the "fragment mass function" (FMF) with the IMF and also want to study its variations as a function of starless and proto-stellar clumps which, in the proposed region appear to be segregated to different filaments. The l=224 field has a well defined distance, it is relatively nearby, and offers the possibility to carry out the proposed analysis with a very good statistical significance. Our simulations show that ALMA+ACA in band 6 offers the best trade-off for both continuum and spectral line observations. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-01-13T14:59:20.000 |
| 3936 | 2023.1.01011.S | 0 | Revealing the molecular gas content of low-metallicity low mass strongly lensed galaxies | In the past decades, studies of massive high-z galaxies have revealed a strong relation between molecular gas and the rates and timescales of star formation. When exploring the lower mass range with, the help of gravitational lensing, galaxies have appeared to have less gas and/or to use their gas more rapidly than expected . This apparent gas deficit (relative to massive galaxies) can either be due to the systematic uncertainties of tracer-to-gas calibrations or to a fundamentally different mode of star formation taking place in these lower mass galaxies, but testing this can only be addressed with larger samples. Here we propose CO observations with ALMA and dust continuum observations with ACA of six low-mass strongly-lensed star-forming galaxies at z~2-3. These observations will significantly expand the current sample of gas measurements in such objects, with the goal of improving statistics to confirm (or discard) the observed deficit. Additionally, by using two independent tracers we address some of uncertainties of tracer-to-gas calibrations. Note: this is a re-submission of a Cycle 9 accepted project, here we request completion of the 10 remaining SGs. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2025-04-05T20:30:12.000 |
| 3937 | 2022.1.00919.S | 0 | Confirming size-dependent dust trapping from multi-wavelength polarization observations | We propose to observe multi-wavelength polarization observations of the disk around PDS 70 to estimate the dust size and confirm size-dependent dust trapping. The object has a wide ring outside the planets, so it is an ideal site to test the dust trapping by the planets observationally. Larger dust is trapped and concentrated to the gas pressure maxima center more efficiently, so the dust size is expected to be larger at the dust ring center than at the edges. To confirm the dust size variation across the ring, we propose polarization observations, which is a robust method to constrain the dust size even if the dust is optically thick. The proposed observations will be the first multi-band polarization observations that spatially resolve a dust ring, allowing us to confirm size-dependent dust trapping. We also propose to observe C17O line emission simultaneously to trace the gas radial profile without losing continuum sensitivity. We will reveal the dust trapping efficiency by comparing the dust and gas ring width. | Disks around low-mass stars | Disks and planet formation | 2024-12-20T12:26:09.000 |
| 3938 | 2021.1.00442.S | 12 | Carbon grain sublimation: a new top-down component of protostellar chemistry | Earth's carbon deficit has been an outstanding problem in our understanding of the formation of our Solar System. A possible solution would be the sublimation of carbon grains at the so-called soot line (~300 K) early in the planet-formation process (i.e., protostellar stage). The most likely signatures of this process are an excess of hydrocarbons and nitriles inside the soot line, and a higher excitation temperature for these molecules compared to oxygen-bearing complex organics that desorb around the water snowline (~100 K). We propose a pilot program toward two nearby high-mass protostars that exhibit signatures of carbon grain sublimation. These observations will spatially resolve the soot line and are able to reveal whether an enhancement in column density of nitrogen-bearing molecules occurs across the soot line. Moreover, these observations will show whether it is necessary to resolve the soot line, or whether excitation temperatures measured over larger spatial scales are sufficient. In addition to establishing whether carbon grain sublimation could be active toward the two sources in our sample, this program will inform future studies of low-mass protostars. | High-mass star formation, Astrochemistry | ISM and star formation | 2022-10-18T21:52:17.000 |
| 3939 | 2017.1.00670.S | 98 | Diurnal Variations in Molecular Species on Io | We request time to observe Io going into and emerging out of eclipse. When Io goes into eclipse the SO2 (and likely SO) atmosphere will collapse. Only volcanic species are expected to remain. We will observe how fast the atmosphere is collapsing, and which species remain. We will observe the species SO2, SO, and KCl. | Exo-planets, Solar system - Planetary atmospheres | Disks and planet formation | 2019-10-12T10:45:12.000 |
| 3940 | 2024.1.01125.S | 0 | Phosphorous in the Earliest Stages of Low-mass Star Formation | The element phosphorous is essential for the development of life on Earth. Therefore, one of the most intriguing places to search for phosphorous is in low-mass (M < a few solar masses) star forming regions, where Sun-like stars and Earth-like planets form. To date, only toward a handful of low-mass protostars have P-bearing molecules been detected, and in only one are there resolved maps published showing the emission can be correlated with the localized shocked material (e.g., traced by SiO) and filamentary structure (e.g., traced by CH3OH). Recent observations from single-dish data have detected the P-bearing molecule PN in another region and for the first time toward a cold (~10 K) and more diffuse (n~10^5 cm^-3 and sizes ~ 6,000 AU) prestellar core, which now requires higher resolution observations. With ALMA Band 1 we propose to map simultaneously PN, SiO and CH3OH toward this shocked prestellar core at appropriate core scales (5'' or ~1,500 AU) in order to investigate the distribution and emission origin of PN in a new environment not mapped in this species before. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 3000-01-01T00:00:00.000 |
| 3941 | 2015.1.00927.S | 44 | Luminous, Dust-Enshrouded High-z Galaxies Selected by Gamma-Ray Bursts | Recent observations have demonstrated that a substantial fraction of GRBs originate from heavily dust-obscured and luminous galaxies at z>1, a population that until recently was not thought to produce GRBs in significant numbers. This discovery has important implications for the connection between GRBs and the overall star-formation rate, suggesting that GRBs can occur in massive and dusty galaxies under certain conditions. We propose to obtain ALMA continuum observations of the ULIRG hosts of six GRBs at z~2 to directly measure their obscured star formation rates, resolve the structure of the hosts in dust emission, and determine whether the bursts originate from compact super-starbursts or more classical modes of star formation. These observations will fill a critical gap in our knowledge of the GRB population, identifying the physical conditions necessary to form GRBs in the high-redshift universe and providing new insight onto the nature of the GRB progenitor and its ability to probe conditions in the most dust-enshrouded galaxies. | Galaxy structure & evolution, Gamma Ray Bursts (GRB) | Galaxy evolution | 2017-09-10T13:12:35.000 |
| 3942 | 2011.0.00010.S | 0 | The Physics and Chemisty of Gas in Centaurus A and its Host v0.6 | Centaurus A with its host NGC5128 is the most nearby radio galaxy. Its molecular spectrum exhibits three prominent features: a) gas that is located in the outer disk and dust lanes, b) absorption lines that are supposedly close to the central AGN, and c) gas in emission from the nucleus. We propose to observe the absorption system in a variety of molecular lines. The molecular lines are chosen to be tracers of column and volume density, temperature, photon- and X-ray dominated regions (X-ray dominated regions are a crucial marker for gas close to the supermassive black hole), shocks and excitation conditions. This will allow us to derive the physical state of the gas at each spectral component as well as the chemistry involved. Our goal is to derive the origin and physics of each absorption component, reaching from the central black hole, through the region that supplies the supermassive black hole with material, regions of possible infall or outflow, the stellar disk and the outer dust lanes. This ALMA proposal will complement a comprehensive survey of the 1.2cm and 7mm lines of an approved ATCA program, which contains tracers of temperature and also lower transitions of the molecules to be observed with ALMA. Together, the ALMA and ATCA data will form a truely unique spectral survey for a radio galaxy and will much likely become the template for all searches of molecular tracers in similar objects at all cosmic epochs. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2015-02-12T13:48:59.000 |
| 3943 | 2016.1.00629.S | 64 | Ice Desorption Illuminating Hidden Planetary Companions | In the early phases of planet formation, young gas-giants still embedded in their parent disks are luminous, ~(1-10) x 10^-4 Lsun, both during the accretion phase and immediately after (within a few Myr). Using 3D chemical models, we found that these planets provide more than enough heat to locally sublimate ices, thereby creating a unique gas phase signature surrounding the planet itself, spanning ~5 AU for a Jupiter-mass protoplanet. Furthermore, the relevant chemical processes (freeze-out and thermal desorption) are rapid compared to disk rotation, and thus the signature follows the planet in its orbit. We propose to apply this chemical imaging technique to search for young, Jupiter-mass planets in the TW Hya protoplanetary disk, where fine-scale ringed structure was recently discovered with ALMA (Andrews et al. 2016), perhaps indicative of the early stages of planet growth. By looking for the youngest planets (i.e., ones that are either just beginning to form gaps or have not yet cleared their orbits), we can put unique constraints on the driving mechanisms of planet formation in disks around solar-type stars. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2020-01-18T00:00:00.000 |
| 3944 | 2012.1.00350.S | 0 | Probing photoevaporation in protoplanetary disks: the primordial to debris disk transition | Understanding the evolution of circumstellar disks around young stellar objects is crucial for theories of star and planet formation. Most young stellar objects are either accreting classical T Tauri stars with "full" disks or non-accreting weak-line T Tauri stars (WTTSs) with bare stellar photospheres, which implies that the transition phase between the two states must be very short. Currently, the only mechanism able to consistently explain the rapidly vanishing disks is photoevaporation by EUV/FUV or X-ray radiation. The photoevaporation of circumstellar gas is expected to mark the transition from the primordial to the debris disk stage. The objects most likely to be caught in this crucial disk evolution phase are WTTSs with weak levels of IR excesses. Such objects represent 20% of the WTTSs population, but the dust and gas content in their disks remain unknown. Here we propose to obtain deep continuum and CO line observations of 22 WTTS in 3 nearby (d ~ 160 pc) star-forming regions (Taurus, Lupus-Scorpius, and Chameleonis) in order to: 1) Conclusively distinguish between primordial photoevaporating disks from young debris disks for the first time in a sample of WTTSs, 2) Constrain disk photoevaporation rates by measuring the mass of primordial disks with photoevaporation-induced inner holes, which is key to test the predictions of different photoevaporation models (e.g., EUV, FUV, and X-ray photoevaporation), and 3) Constrain models of the early evolution of debris disks and the onset of the debris disk phenomenon. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2014-12-20T00:00:00.000 |
| 3945 | 2018.1.00558.S | 39 | The role of molecular gas in quenching star formation of green valley galaxies | How the star formation of galaxies gets quenched and how galaxies migrate from the star-forming sequence to the quiescent population remain unanswered. In our Cycle 3 program, we obtained CO (1-0) observations for three galaxies in their transitional phase, the so-called `green-valley' galaxies, selected from an integral field unit (IFU) survey of nearby galaxies, MaNGA. We found that the molecular gas plays a different role in the star formation quenching between bulge and disk. In addition, the data show clear dependence of the kpc-scale specific star formation rate (sSFR) on the gas fraction and star formation efficiency (SFE) in both bulge and disk regions. In order to robustly establish the trends we found based on a limited Cycle 3 sample, we propose to increase the resolved CO(1-0) sample size by observing additional 25 MaNGA galaxies whose sSFR are on and below the star-forming main sequence. The resolved gas observations from ALMA, combined with the resolved stellar populations from MaNGA, will allow us to shed light on the role of cold molecular gas in the star formation history as well as the quenching process in galaxies. | Surveys of galaxies | Galaxy evolution | 2020-03-18T06:43:06.000 |
| 3946 | 2016.1.00744.S | 20 | Investigating the water deuteration in a young protostellar system | The evolution of water from its formation in the molecular cloud until its incorporation in the protoplanetary disk and then comets and asteroids is still unclear. Measuring the water D/H ratio is particularly helpful to answer this question. We propose to carry out multi-line observations of the water isotopologues (HDO, H2-18O and D2O) at high spatial resolution (0.3 arcsec, 35 AU diameter) towards the inner regions of the well-known Class 0 protobinary IRAS16293-2422, which is now possible thanks to the enhanced capabilities of ALMA. Through the study of the kinematics and the determination of the HDO/H2O and D2O/H2O ratios with radius from the protostars, we can determine if the water present at the Class 0 stage was preserved or reprocessed until its incorporation in disks and primitive icy bodies. The data will also allow us to determine the mechanisms that control the water vapor abundance in the warm inner regions of Class 0 protostars. This proposal is a resubmission of the B-ranked proposals 2013.1.00061.S and 2015.1.00475.S. Observations of 5 science goals (among 7) were carried out. If observed in Cycle 3, the 2 remaining science goals do not need to be re-observed. | Low-mass star formation | ISM and star formation | 2018-05-13T04:40:39.000 |
| 3947 | 2015.1.00026.S | 26 | A resolved view to the dust content in star-forming Halpha galaxies at z = 1.47-2.23 | This re-submitted proposal (approved but not observed in Cycle-2) aims to obtain spatially resolved imaging of the dust content in 8 high-z Halpha galaxies taken in two redshift slides, z=1.47 & 2.23 of the HiZELS survey. The targets have been observed with VLT/SINFONI and Gemini-N/NIFS, both AO-aided, up to an exquisite resolution of 0.2" equivalent to ~kpc-scales at those redshifts. All targets are normal 'main sequence' galaxies that show thick disks co-rotating with massive clumps of star-formation. These clumps have typical star-formation rates that are ~15x higher than that seen in local HII regions. The combination of ALMA and the available IFU-AO data provides a unique and novel approach to decribe the star-formation rate using two gold-standard tracers at matched ~0.2" resolution in high-z galaxies. Mapping the dust with ALMA is key to constrain the extincion suffered by the star-light, i.e. critical to account for the obscured star-formation activity. High resolution ALMA observations for this new AO-aided sample are key to provide a decisive argument on the nature of the clumpy structures, therefore essential to understand how star-formation is being triggered at high-z. | Galaxy structure & evolution | Galaxy evolution | 2017-11-07T17:16:57.000 |
| 3948 | 2023.1.01127.S | 0 | Determining the Complexity of the Accretion Streamers Feeding the Protostellar Disk in Lupus 3-MMS | The chemistry and dynamics of the mass delivered to protostellar disks via accretion streamers are crucial for the development of the protostar, future planetary systems, as well as, potentially life itself. Recent observations ofstreamers in Per-Emb-2 and IRAS 16293-2422 demonstrate that several different molecular species, and multiple transitions of each species, are needed to confirm and characterize streamers in protostellar cloud cores. We propose a Band 3 chemical survey of a unique Class 0 protostar, Lupus 3-MMS, with multiple asymmetric streamers and a well-characterized rotationally-supported disk. Our observations will cover a total of 16 different species and 30 total transitions that trace components of the cold, dense, chemically fresh and chemically evolved gas with high spectral resolution from scales of 160 au (near the disk) to 9000 au (in the outer envelope). We will trace the kinematics by matching to a simple infall model and constrain physical properties, such as, temperature, density and abundances using 3D radiative transfer calculations to provide a more complete picture of the accretion environment. | Low-mass star formation | ISM and star formation | 2024-12-08T13:14:48.000 |
| 3949 | 2013.1.01188.S | 6 | A resolved view to star-forming Hα galaxies at z = 1.47-2.23: exploiting the synergy between ALMA and AO-IFU | This proposal aims to obtain spatially resolved imaging of the dust content in 8 high-z Halpha galaxies taken from two redshift slides, z = 1.47 & 2.23, of the HiZELS survey. The targets have been recently observed with VLT/SINFONI and Gemini-N/NIFS, both AO-aided, up to an exquisite resolution of 0.2" equivalent to ~kpc-scales at those redshifts. All targets are normal `main sequence' galaxies that show thick disks co-rotating with massive clumps of star-formation. These clumps have typical star-formation rates (SFRs) that are ~ 15x higher than that seen in local HII regions. The combination of ALMA and the available IFU-AO data provides a unique and novel approach to describe the star-formation rate using two gold-standard tracers at matched ∼0.2" resolution in high-z galaxies. Mapping the dust with ALMA is key to constrain the extinction suffered by the star-light, i.e. critical to account for the obscured star-formation activity. High resolution ALMA observations for this new AO-aided sample are key to provide a decisive argument on the nature of the clumpy structures, therefore essential to understand how star-formation is being triggered at high-z. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2016-10-16T19:23:49.000 |
| 3950 | 2012.1.00743.S | 62 | Detection and characterization of protoplanetary disks across the stellar/substellar transition | With the powerful combination of the sensitivity of ALMA and an ideal sample of 32 young, low-mass objects, we propose to measure the population statistics of protoplanetary disks over the stellar/substellar transition. By targeting objects detected in our 70um and 160um Herschel surveys, we have maximized both the probability of detection and the coverage of the SEDs, important for the characterization of disk properties. We will model the well-sampled SEDs with the state-of-the-art radiative transfer code MCFOST. ALMA is essential to enable the transformation from small number detections of the brightest few objects to a comprehensive understanding of disk properties such as mass and their viability for planet formation. The targets were selected to belong to two distinct, well known, Star Forming Regions. They are located in Taurus and Upper Sco and cover two ages (~2Myr and ~10Myr), enabling an investigation into the evolution of disks over the critical age range during which planets may form and interact dynamically with disks. By targeting the Taurus region previously surveyed with single dish surveys, we will efficiently complete a comprehensive survey across the full mass spectrum by combining the proposed ALMA study with existing measurements. | Disks around low-mass stars | Disks and planet formation | 2015-11-18T13:05:22.000 |
| 3951 | 2021.1.00455.T | 24 | Triggered follow-up of accretion outbursts in massive protostars | The recent discovery of accretion outbursts in 3 high-mass protostars (NGC6334I-MM1, S255IR-NIRS3, and G358.93-0.03MM1) has rapidly impacted the traditional view of massive star formation, motivating new hydrodynamic simulations of massive protostellar accretion. All 3 events were heralded by flaring of the 6.7GHz methanol maser line, which is pumped by the increase in IR photons due to the sudden increase in accretion rate. The most recent event led to the first discovery of (sub)mm methanol masers from torsionally-excited states in the gas surrounding the protostar. We seek Target of Opportunity time, to be triggered upon report of the next dramatic methanol maser outburst from the international single-dish Maser Monitoring Organization. Our primary goals are to identify the outbursting protostar within its protocluster, obtain a 4-epoch light curve of the outburst to measure the magnitude and duration in the most suitable Band, determine if the torsionally-excited methanol masers are a common occurrence in such events or are unique to G358.93-0.03, and perform a unique test of the RAT dust grain alignment mechanism by searching for a change in the dust polarization fraction. | High-mass star formation | ISM and star formation | 2024-10-03T15:10:54.000 |
| 3952 | 2021.1.01297.S | 18 | Investigating Sites of Dense Galaxy Build-up in the Epoch of Reionization | We propose to perform [OIII] 88um emission and dust continuum observations of two fields: REBELS-12 and REBELS-39. Both fields have UV-bright LBGs at z~7, which have [CII] emission line detections from a recent ALMA survey (2019.1.01634.L). Additionally, these two fields include complete surprises by showing detections of serendipitous [CII] emitters in the spatial and spectral proximity of the UV-bright LBGs. These two [CII] emitters are completely absent in rest-UV observations, showing us dense environments completely missed from rest-UV observations. The [CII] line detections, thus, started to show complete pictures of the site of massive galaxy assembly, unrecognized from rest-UV observations. However, as only [CII] emission lines have been detected, origins of the [CII] emission lines are unclear. Proposed observations will allow us to discriminate possible scenarios of the origins of these serendipitous [CII] emission: dusty massive galaxies? or highly ionized gas rich but low-SFR satellites? or even ionized outflowing gas? In addition, the proposed observations will probe the detailed ISM structures of UV-bright LBGs at the same time. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2023-05-16T15:26:37.000 |
| 3953 | 2022.1.00874.S | 10 | Measuring dynamically the disc mass of WaOph 6 through CO kinematics | Measuring the gas mass in protoplanetary disks is one of the biggest challenges in the planet formation community. Traditionally, this has been done by converting the measured flux either in the dust continuum or in the CO line emission, assuming appropriate conversion factors. Here, we propose a radically different approach, unaffected by systematics associated with dust or CO abundance: to measure dynamically the gas mass by observing the deviations from a purely Keplerian rotation curve, that are expected when the disk mass is large enough. The power of this technique has already been shown in the case of Elias 2-27, and we now request to perform a similar analysis for Wa Oph 6, that also shows hints of possessing a massive disk. We thus propose high spectral resolution and high sensitivity ALMA observations of the 13CO and 12CO gas emission in the disk orbiting around WaOph 6. Specifically we request deep Band 7 observations at 0.1 arcsec spatial resolution and 25 m/s spectral resolution to trace the gas component of the disk and study the deviation from Keplerian motion induced by the disk self-gravity in the rotation curve. | Disks around low-mass stars | Disks and planet formation | 2024-08-14T15:23:36.000 |
| 3954 | 2022.1.00014.S | 439 | Forsaken pre-Planetary Nebulae: CO emission observations | Astronomers have long been puzzled by the morphological variety and bizzare shapes of planetary and pre-planetary nebulae (PNe and pPNe). The majority of pPNe studies have selectively focused on objects with spectacular morphologies and kinematics, however, the latter may not represent the whole pPN class but rather a group of pPNe with extreme properties (and binary central stars), which are being extrapolated to the whole family of pPNe. This is part of a coordinated effort aimed at characterizing at multiple wavelengths a statistically significant number of bonafide pPNe candidates, with unequivocal indicators for the presence of circumstellar material, that have been systematically overlooked from most follow up studies to date -- dubbed forsaken. We propose to observe the CO line emission in these systems as it is the best diagnostic to investigate what kind of nebular structure accommodates the circumstellar material that is present in these objects. Forsaken pPNe is the place to look for the, yet unidentified, post-AGB descendants of single ~1-8Msun stars and the missing link population between two major classes of pPNe identified to date (wind-prominent and disk-prominent). | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2023-10-10T14:02:58.000 |
| 3955 | 2016.1.00324.L | 273 | ASPECS: The ALMA SPECtral line Survey in the UDF - An ALMA Large Program | ASPECS represents an unparalleled three-dimensional survey in a contiguous 4 arcmin^2 region in the Hubble UDF, the ultimate cosmological deep field, designed to trace the cosmic evolution of cool gas and dust. This blind survey is the necessary complement to the well-explored areas of stars and star formation, thereby completing our understanding of the baryon cycle from gas to stars over cosmic time. Building from techniques developed in our cycle 2 pilot program, we will perform spectral scans of bands 3 and 6 in the UDF. ASPECS will provide foundational insights into galaxy formation, including the crucial, and currently poorly constrained, areas of: (i) the evolution of the molecular luminosity function and the cosmic density of H2, (ii) the molecular gas fraction and excitation vs. galaxy parameters and epoch, (iii) [CII] emission from the first galaxies (z>6), and (iv) the dust content of normal star-forming galaxies back to cosmic reionization. The proposed observations are the natural and essential legacy of ALMA in the new era of 3D precision studies of galaxy formation, as epitomized by existing, and planned multi-wavelength campaigns in the UDF. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-10-09T16:00:13.000 |
| 3956 | 2017.1.00586.S | 61 | Effects of active galactic nucleus and starburst in NGC 1068: High resolution images of neutral carbon (CI) | We propose to obtain high resolution (~0".6) images of neutral carbon (CI) at 492 GHz toward the nearby Seyfert galaxy NGC 1068. Abundances of atoms/molecules and the understanding of physical and chemical processes are fundamental for astrophysics and astrochemistry. In galaxies one of the interesting topics is the effect of X-rays from AGNs (active galactic nuclei) on interstellar matter. We have obtained images of several molecules with ALMA band 3 and 7 toward NGC 1068 covering the nuclear region and the surrounding starburst ring. The images demonstrated distributions of the molecules in one or both of these extreme regions. These images were excellent for the study of the above processes. Encouraged by these results, we propose to observe images of CI. The distribution will provide valuable data to study the effects of X-rays, cloud age, and relation to carbon-chain molecules. Three interesting positions selected based on our previous study will be observed including the center. This study will also be useful as a template to interpret CI data in high-z galaxies. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-07-05T13:49:49.000 |
| 3957 | 2012.1.00496.S | 7 | Calibrating Disk-Based Dynamical Mass Estimates with Young Spectroscopic Binaries | A more robust knowledge of young star masses would be incredibly valuable in the analysis of many aspects of star and planet formation. In principle, we can derive precise (uncertainties of ~a few %) dynamical masses from the rotation curves of molecular gas disks that orbit young stars. But in practice, that disk-based technique relies on a complex modeling process: its absolute accuracy is not clear. There is a straightforward way of validating this technique, which relies on observing the few systems where two independent dynamical mass estimates are available -- spectroscopic binaries with circumbinary disks. By comparing constraints from ALMA observations of CO gas in these disks with those from optical radial velocity variations from the stars, we can absolutely verify and calibrate the disk-based method for estimating stellar masses. Ultimately, the results of this calibration can be applied to similar data for any isolated (single) young star, vastly increasing the database of dynamical stellar masses. To that end, we propose to observe the 12CO/13CO/C18O J=2-1 lines from the four circumbinary disks known to orbit pre-main sequence spectroscopic binaries (around GW Ori, AK Sco, UZ Tau E, and DQ Tau) that do not yet have firm dynamical mass measurements. | Disks around low-mass stars | Disks and planet formation | 2016-08-13T00:00:00.000 |
| 3958 | 2016.1.00870.S | 19 | SgrA* Accretion Confirming a possible ALMA detection of Broad H 30alpha Emission | We propose a search for HI 30alpha recombination line emission from the accretion zone of the Milky Ways galactic center super massive black hole SgrA*. This observation is triggered by the possible detection of the recombination line in our project in Cycle 2 and the detection of broad a HeI recombination line in NIR (Hall et al 1982). [Our present ALMA data have serious problems with the quality of the passband calibration.] Our proposed technique is unique for studying the accretion zone. X-ray emission cannot probe 10^4 K gas (which is the likely accretion reservoir), and radio free-free emission is overwhelmed by the strong synchrotron radiation. ALMA sensitivity is such that the proposed observation would detect approximately a Jupiter mass of HII in the accretion zone at less than 0.01 pc. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2018-11-03T19:18:37.000 |
| 3959 | 2013.1.00833.S | 1 | Using CI to Map the Real Structure of a Low-Metallicity Starburst | Low-metallicity environments frequently exhibit starburst behavior, forming most of their stars in massive clusters. The physical conditions in the molecular ISM must dictate this distinct mode of star formation. Unfortunately, our typical tracer of the molecular ISM -- CO emission -- is confined to the densest parts of molecular clouds. Instead, much of the molecular gas is colocated with atomic carbon. We propose using CI to characterize molecular gas using ALMA's superior resolution (both spatial and spectral) and surface brightness sensitivity to map the bulk of the molecular clouds in the nearby low-metallicity starburst NGC 5253. In this low metallicity environment, we expect a larger fraction of the molecular gas to be traced by the CI instead of the CO. With these data, we will (1) measure the properties of molecular clouds in a low metallicity starburst and (2) establish the connection between the molecular ISM and the rich population of young clusters imaged by Hubble. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2016-09-05T02:21:04.000 |
| 3960 | 2016.1.00592.S | 35 | The First Constraints on the Volatile Nitrogen Abundance in TW Hya | Low nitrogen abundances in solar system bodies suggest that much of the nitrogen in the forming solar system was in the gas phase. At the same time recent observations reveal that, in the nearby protoplanetary disk TW Hya, CO is depleted by nearly two orders of magnitude throughout the disk. Like N2 is for nitrogen, CO is one of the primary carriers of gas phase carbon and the two molecules undergo similar chemical reprocessing. Currently, the abundance of N2 in TW Hya has no observational constraints. We propose to determine the N2 abundance relative to CO in TW Hya as a function of radius using the tracer species N2H+ and H13CO+. These observations will provide the first observational constrains on an important nitrogen bearing species, determining if the depletion seen in CO is also occuring to N2. | Astrochemistry | ISM and star formation | 2018-01-07T14:48:46.000 |
| 3961 | 2021.1.00033.S | 10 | Hydronium toward PKS1830-211 | We propose observations with one tuning in Band 10 to detect the absorption of hydronium (H3O+) and oxidaniumyl (H2O+) in the z=0.89 molecular absorber toward the bright lensed quasar PKS1830-211. These observations will allow us to probe the chemistry of the oxygen hydride ion family, and measure in a robust, self-consistent analysis the molecular hydrogen fraction, the cosmic-ray ionization rate of atomic hydrogen, and the electron fraction in the disk of a z=0.89 galaxy, i.e., at an epoch close to the cosmic peak of star formation rate density. We will also measure the rotation temperature of H3O+ and test the universality of formation pumping excitation. The molecular absorber toward PKS1830-211 is the only intermediate-to-high redshift object for which such a detailed chemical analysis can be done, providing a benchmark for distant star-forming galaxies. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-07-13T09:42:31.000 |
| 3962 | 2016.1.01144.S | 253 | Infall and outflow in a filamentary hub | With this proposal we aim at understanding the processes of cloud gas feeding and HII region feeback that lead to the formation of high-mass stars. We plan detailed high-spatial resolution maps in different species (13CO, C18O, CS, C34S, SO, H40a) to study the close-by high-mass star forming region MonR2: an expanding HII region embedded in a dense hub surrounded by converging filaments. Previous observations reveal a complex kinematics along the filaments, likely tracing the accretion of material from the outside to the central hub, where we find spiraling arms converging towards the expanding HII region. Thanks to the high-spatial scales that can be probed in this region, MonR2 is an excellent target to study the dynamic and kinematic properties of filamentary hubs in an environment of high UV radiation. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-03-24T03:25:35.000 |
| 3963 | 2016.1.01086.S | 38 | Revealing the dynamic of solid particles in the HD 163296's ringed disk | Using ALMA Band 6 observations, we have recently discovered that the disk surrounding the young Herbig Ae star HD 163296 is characterized by a ringed structure similar to that observed toward HL Tau. We now propose to map this object in dust continuum emission at the wavelengths of 3 mm (Band 3) and 0.87 mm (Band 7) to measure the grain size distribution across the observed rings down to a spatial scale of about 10 AU. These measurements will probe the radial migration of dust particles and will reveal whether the observed ring-shaped structures are capable of trapping dust grain. The proposed research directly addresses the long-standing paradox related to the too fast inward migration of solids predicted by theoretical models. | Disks around low-mass stars | Disks and planet formation | 2018-10-19T18:28:21.000 |
| 3964 | 2015.1.00582.S | 28 | Redshifted Molecular absorption from the z=0.765 spiral lens towards PMN0134-0931 | We propose to use ALMA to carry out a deep search for redshifted CO(2-1) and HCO+(2-1) absorption from the z=0.765 gravitational lens towards PMN0134-0931. The proposed observations will be sensitive to CO(2-1) and HCO+(2-1) absorption against even the weakest of the lensed images, assuming that the absorption is optically thick. The observations should result in the detection of a new mm-wave molecular absorber at z=0.765, allowing a new probe of molecular chemistry at intermediate redshifts, as well as of fundamental constant evolution. We request a total observing time of 5.9 hours for this project, including all calibrations. | Gravitational lenses, Damped Lyman Alpha (DLA) systems | Cosmology | 2018-03-20T19:28:56.000 |
| 3965 | 2019.1.01305.S | 43 | The direct measurement of the bar pattern speed of galaxies | Bar pattern speed is the one of the key parameters to understand galactic structure formation. Furthermore, past studies of the bar show that the bar pattern speed gets slow as time passes. Depending on the difference of the degree of the central concetration of dark matter or dynamical age of bar, bar slows down by the dynamical friction of the dark matter halo. Thus, it is important to measure the bar pattern speed correctly. We propose CO(2-1) observations of nearby barred galaxies whose bar is aligned in the direction of the major axis of the galaxy. Since molecular gas is expected to flow along the offset ridge in the bar as shown in many simulations, we can measure the bar pattern speed in these galaxies by using the method proposed by Kuno et al. (2000). In this proposal, we observe 6 barred galaxies that differ in bar lengths, star formation activities, and morphological types. We study the relation between the bar pattern speed and above conditions, and physical property of gas along with the verification of standard CDM cosmology. In futrue, we will clarify the structure and evolution of the barred galaxies including dark matter from distant galaxies to nearby galaxies. | Spiral galaxies | Local Universe | 2021-04-22T15:45:35.000 |
| 3966 | 2015.1.00736.S | 32 | Mapping the Morphology, Kinematics, and Excitation of Molecular Gas in Arp 220 | Our ALMA cycle-0 observations of the CO J = 6-5 line in Arp 220 resolved the morphology of the warm molecular gas for the first time, revealing complex new features in the morphology and kinematics of the individual nuclear disks and the large-scale foreground gas distribution surrounding them. Multiple CO transitions are needed to characterize the cold and warm molecular gas, i.e, determine spatial variation in the optical depths, excitation and column densities as well as measure any changes in the morphology and kinematics as a function of CO rotational transition. We request 12CO line and continuum maps for J = 3-2, 4-3, 7-6, 8-7 to (a) characterize the foreground large-scale gas distribution and measure its mass and excitation, (b) measure the spatial variation in excitation and kinematics by comparing the low-J and high-J lines and (c) resolve the continuum source in the western nucleus to help determine whether the source of far-infrared luminosity is an AGN or a compact starburst. We also request 13CO J=4-3 and 6-5 observations to discriminate between absorption and outflow models and to determine the 12CO/13CO abundance ratio in an extreme star formation environment. | Starbursts, star formation | Active galaxies | 2018-03-13T17:53:04.000 |
| 3967 | 2017.1.01306.S | 44 | Tracing the Enrichment of the ISM in Extreme Starbursts | We propose to observe four sources that are undergoing or have undergone recent extreme star formation in 12CO, 13CO and C18O to trace the enichment of the ISM via stellar nucleosynthesis. The C18O traces nucleosythesis and can distinguish enrichment from pristine gas inflow. We will use the proposed observations to search for morphological evidence of enrichment, similar to that what was osberved for IRAS13120-543. We will also perform a non-LTE analysis to constrain the relative abundances of the species and compare them across the four sources and results in literature to look for any trends with merger stage. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2019-11-26T11:49:04.000 |
| 3968 | 2013.1.00220.S | 39 | Disk Demographics in Lupus | We propose to survey the gas and dust in 98 protoplanetary disks in the nearby Lupus star forming region. This is a complete sample of all known optically visible stars with large infrared excesses and stellar masses > 0.1 solar. We will observe the 13CO and C18O 3-2 lines and have developed models to derive total gas masses and surface density profiles. The sensitivity of these data is a few Martian masses (0.2-0.4 Earth) in the dust and Saturnian masses (0.1-0.3 Jupiter) in the gas. We will be able to detect the lowest mass disks in both the continuum and line for a gas-to-dust ratio similar to the ISM. We will observe to about 20 AU linear resolution, sufficient to measure sizes and surface density profiles in all but the smallest disks. At these scales we also expect to see features such as inner holes and azimuthal asymmetries that may signpost planet formation. The sample size, sensitivity, and resolution of this survey will provide much needed demographics for disk studies and planetary synthesis models. To maximize its impact, we will reduce the proprietary period to 3 months and make the data products available through a dedicated disk archive within 1 year. | Disks around low-mass stars | Disks and planet formation | 2016-09-04T23:20:14.000 |
| 3969 | 2015.1.00546.S | 8 | A Comprehensive View of Magnetic Fields around Young Protostar NGC1333 IRAS 4A | The hourglass morphology of NGC1333 IRAS 4A's magnetic field structure has been seen as the textbook example for low-mass star formation under the influence of magnetic field. We have obtained SMA dust polarization data with all available array configurations. ALMA now offers unprecedented high sensitivity at high angular resolutions and high image fidelity that, with the observations we request, we will be able to (1) obtain the most comprehensive view of magnetic field structure around a low-mass proto-binary and trace the variation of the field morphology at the Class 0 stage within ~ 30-1300 AU scale range, (2) reliably test the theoretical models, and (3) probe the turbulence power spectrum and its energy dissipation scale in the envelop. | Low-mass star formation | ISM and star formation | 2017-12-02T05:12:06.000 |
| 3970 | 2013.1.00991.S | 7 | The full anatomy of a minor merger | Minor mergers constitute the majority of interacting events in the nearby Universe - they are important to understand galaxy evolution processes. The gas accretion and nuclear feeding mechanisms of these mergers are different from major mergers. Molecular gas may flow along the large-scale dust lanes to form polar rings in their centres, with this material acting to fuel both star-formation and nuclear accretion. Tracing this gas is vital if to understand the mechanisms of this class of mergers. NGC1614 is a spectacular example with a prominent minor axis dust lane. We propose ALMA observations of 12CO and 13CO1-0 to study the location and content of the larg-scale gas reservoir, how its molecular content changes with radius, and how it becomes funneled into the dust lane. Why is the gas in the dust lane not forming stars? How is it dynamically coupled to the starburst ring? The proposed observations will study the life cycle of the molecular gas, from its origins on kpc-scale to the nuclear region where this fuel is converted into stars. Only these ALMA observations will provide the multi-scale and high-sensitivity imaging of the gas which will fully link the distinct gas phases. | Merging and interacting galaxies | Galaxy evolution | 2016-01-18T15:06:00.000 |
| 3971 | 2017.1.00704.S | 169 | Getting the composition of exocomets with ALMA | Thanks to ALMA, CO gas has been detected around ~10 main sequence stars with infrared excesses. This comes as a surprise as debris discs were expected to be gas free. In most of these systems, CO is thought to be of secondary origin, released from solid bodies of debris belts. CO is then quickly photodissociated by impinging UV radiation and transforms into C+O that viscously evolve spreading all the way to the star. In Kral et al. (2017), we developed a new way of estimating the level of CO from observations of the dust, and used that to show that it should be possible to double the number of CO detections by targeting specific sources. Moreover, we can use the CO observations to constrain the CO content of the planetesimals. Here, we propose to observe CO in the 10 most favourable systems that were selected using the new gas model results from Kral et al. (2017) that is a paper dedicated to make predictions for ALMA. This survey will constrain the CO gas mass in these >10Myr systems, test the hypothesis that secondary CO gas is ubiquitous in debris discs at levels that can be predicted reasonably accurately, but above all provide the CO-to-solid ratio in these systems' exocomets. | Debris disks | Disks and planet formation | 2019-05-10T16:24:44.000 |
| 3972 | 2019.1.00851.S | 6 | High resolution investigation in the core of the "baby" quasar IRAS 00183-7111 | IRAS F00183 is a peculiar ULIRG which is likely been caught in the brief transition period between a starburst-dominated ULIRG and a quasar. This source appears to be a low-redshift analogue of the high-redshift radio galaxies, offering the unique opportunity to study one of these objects with high detail. The analysis of existing ALMA Band 3 data gives us intriguing hints: a molecular outflow is tentatively detected and may form part of a large-scale AGN wind-driven outflow; a 2.5 kpc line-continuum observed is observed and may be caused by an interaction between the "new-born" jets and the surrounding molecular gas. However, the spectral and spatial resolutions of the archival data are too low (90 km/s and 3") to allow a detailed morphological and kinematical study. Here we propose new Band 3 continuum and CO(1-0) observations of IRAS F00183, with a spectral resolution of 20 km/s and a spatial resolution of 0.3" (five and ten times better, respectively, than the existing data). The requested setup will allow us to perform a detailed analysis of the scenarios described above, providing a crucial comparison with existing studies on lower-redshift and less extreme ULIRGs. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2022-08-19T16:00:00.000 |
| 3973 | 2023.1.00662.S | 0 | Dust Temperatures in 70um Dark IRDCs | [Resubmission of unfinished accepted proposal that was heavily affected by cyber-attack, only 15% so far completed.] Dust temperatures and masses are key physical properties of star-forming cores that are generally hard to estimate. Core masses are important to test theories of high-mass star formation as well as to study the universality of the initial mass function. In a survey of 12 (70 um dark) high-mass clumps, a total of 294 low-to-intermediate mass cores (71% prestellar) have been detected at 220 GHz. Unfortunately, due to the lack of temperature information at 1" scales, the conclusions may be misleading and favoring a particular star formation theory. Here, we aim to obtain dust temperatures at the size scales traced by ALMA. We will carry out a spectral energy distribution (SED) fitting from 140 to 470 GHz. With both temperatures and masses estimated at 1" resolution (~4,000 AU), we will tackle the following two questions: 1.) Do high-mass prestellar cores exist at the earliest stages of fragmentation? Can we support or rule out any of the two competing theories? 2.) How does the CMF vary after determining temperatures/masses at the observed core scales? | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-06-19T16:05:11.000 |
| 3974 | 2012.1.00387.S | 4 | The Largest OB Cluster-Forming Disk-Like System? | Observations toward the densest regions of the giant molecular clouds (GMCs) where the radially distributed molecular filaments converge, have found the 0.5-1 pc scale, flattened rotating structures with 1000-10,000 solar mass of gas. These high-mass structures with high-density are likely the most active OB cluster-forming regions in the Galaxy. The >100 solar mass cores/toroids were found at the geometric center of these structures, embedded with L* > 10^5 Lo young OB clusters. The object G33.92+0.11, which is likely in a nearly face-on projection, provides us the chance to directly view the spatial structures in the rotating plane. Our 0".5 resolution observations of the 1.3 mm dust continuum emission with SMA have recently spatially resolved the spiral arm-like features connecting from a 0.3 pc radius to the central <0.1 pc massive disks/toroids. High resolution spectral line observations, however, had been prohibited by the limited sensitivity. Here, we propose to make the best synthesized image with ALMA. The >3 times improved spatial dynamic range is crucial for demonstrating the gaps in between the spiral arm-like features without being confused with the negative intensity sidelobes, and for identifying the ~1 solar mass gas local overdensities located near the central bright massive toroids/disks. The improved sensitivity (16 times better than SMA) will permit us to resolve the detailed motions of the filamentary gas structures with fine angular/velocity resolution for the first time. In addition, the simultaneously covered shock and ionized gas line tracers will probe the localized (proto)stellar feedback within the 0.3 pc scale radius of this rotating accretion flow. The proposed short observations will already tell us about whether these specific environments embedded with filamentary or arm-like features fragment into localized cores, which will contract subsequently and form stars. Alternatively, these filaments could be the spatially more smoothed gas reservoir for the competitive accretion. | High-mass star formation, HII regions | ISM and star formation | 2015-08-08T20:16:35.000 |
| 3975 | 2019.1.00026.S | 6 | Nuclear starbursts in the dense molecular torus in NGC 1068 | We propose <0.06" (<4.2 pc) resolution ALMA band 3 observations of nearby type-2 AGN, NGC 1068, at two hydrogen recombination lines in the millimeter wavelength. Our ALMA Cycle-4 data of dense molecular tracers (HCN and HCO+ J=3-2 lines) revealed clearly, for the first time, the long-sought-after rotating dense molecular torus along the east-west direction in NGC 1068, as expected from the widely accepted AGN unification paradigm. However, we also found that the observed torus properties are much more complicated than simple predictions by the paradigm. We aim to test a nuclear starburst scenario as the origin of the observed non-axisymmetric molecular gas properties between the eastern and western part of the torus. Such nuclear starbursts in the torus, if detected clearly in the proposed dust-extinction-free probes, could also explain (1) the observed rotation much slower than the Keplerian motion governed by the central supermassive black hole and (2) high observed AGN luminosity in NGC 1068. Scrutinizing the torus properties in the archetypical nearby AGN, NGC 1068, will be an important milestone toward understanding the role of torus in the AGN population in our universe. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-11-03T19:30:53.000 |
| 3976 | 2011.0.00876.S | 0 | The Antennae: A Luminous Stellar Nursery | We propose to use ALMA in the extended configuration at Band 7 to simultaneously survey the 850 micron dust continuum, CO(3-2), and the dense gas tracers HCN(4-3), HCO+(4-3), and CS(7-6) in the interaction region (IAR) of the Antennae Galaxies with 0.5" (50 pc) resolution. The Antennae are the nearest prototypical major merger, and may soon evolve into an ultraluminous infrared galaxy. Hence, they offer our best chance to study the anatomy of a young, merger-induced starburst in detail. We will use these observations to identify the cores and clouds that will form the next generation of clusters. Analyzing these in conjunction with our extensive existing panchromatic data, we will build a complete picture of cluster formation from the cloud stage through cluster formation and dissolution. We will measure CO and sub-mm luminosity functions, correlate the sub-mm populations with young clusters, and search for the eminent sites of cluster formation. Because we focus on bright point sources this is a natural application for ALMA in Early Science. Our mosaic extends to the northern IAR which contains many optically dark filaments, not previously studied interferometrically in CO(3-2). In the southern IAR region we will combine our continuum and CO(3-2) data with the to-be-distributed ALMA Science Verification data for greater sensitivity (and shorter uv-spacings). Our interferometric HCN(4-3), HCO+(4-3), and CS(7-6) data will be completely unique. The wide scientific and public interest in the Antennae, and the synergy with our team's HST and EVLA work, promise to make this a high impact, high visibility result. | Merging and interacting galaxies, Inter-Stellar Medium (ISM)/Molecular clouds | Galaxy evolution | 2013-12-31T17:01:00.000 |
| 3977 | 2018.1.00779.S | 51 | The molecular cloud structure in the low-metallicity environment of 30 Doradus | Our understanding of how gas is converted into stars quickly deteriorates as the metallicity of the interstellar medium decreases. While molecular gas is commonly accepted to be the main star-forming reservoir in normal galaxies like our Milky Way, the difficulty in tracing molecules in metal-poor galaxies complicates our ability to evaluate the star-formation efficiency or even the mere importance of molecular gas in the star-formation process. We propose a detailed modeling of the photodissociation front and molecular cloud in the half-solar metallicity environment of 30Dor in the Large Magellanic Cloud, in order to quantify the total molecular gas mass and the fraction of this gas that is not traced by the usual tracer CO (the CO-dark gas). Thanks to our previous modeling effort using Herschel tracers at 10pc resolution, we have identified a optimized combination of ALMA tracers that will provide the sufficient constraints to achieve our goals at 0.1pc resolution, i.e., a scale small enough to examine the transition between physical layers in molecular clouds. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2022-10-25T17:10:13.000 |
| 3978 | 2016.1.00204.S | 13 | Resolving the dynamical link of the eccentric stars in the massive AK Sco system and the hole in its circumbinary disk | Binary stars will often incite dynamical perturbations in their circumbinary disk, such as clearing, warping, and induced eccentricties of planetesimals. In spite of this apparently hostile environment, the Kepler mission has demonstrated that circumbinary planets form readily. The AK Sco system provides an ideal laboratory to study this environment directly, since its advanced age (18 Myr) has provided plenty of time for the processes of planet formation to sculpt the disk. Recent scattered light observations of AK Sco revealed sharp asymmetric features, which are likely the inner edge of a 30 AU diameter dust ring sculpted by the orbit of a giant planet. We propose high resolution (0.1") observations of the dust and gas of AK Sco to directly study this exciting dynamical environment. Dust continuum observations will clearly resolve the cavity seen in scattered light and measure the size of the dust ring, probing the effects of planetary sculpting in circumbinary systems. Dynamical modeling of the gas will precisely measure the inclination and eccentricity of the disk, constraining the influence of the eccentric binary on the structure and dynamics of the protoplanetary disk. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2018-09-08T18:11:39.000 |
| 3979 | 2017.1.00729.S | 70 | Unlocking the Potential of the Most Definitive Molecular Tracer of UV-Enhancement: l-C3H+ | The recently-discovered interstellar molecule l-C3H+ appears to be the most sensitive and definitive molecular tracer of enhanced UV-flux ever observed in the ISM. Extensive, deep searches for this species in dozens of sources show its presence exclusively in UV-enhanced regions. Yet, our understanding of the spatial distribution of the molecule within these sources, and the excitation conditions (and abundances) in previously-observed regions, is sorely lacking. Here, we propose ALMA observations following up on prior detections in three PDR regions with the IRAM 30m telescope to understand the spatial distribution, abundance, and excitation of this potentially transformational molecule in our ability to probe the extent of UV-enhanced flux in these and other key regions. The results will be used to refine state-of-the-art PDR chemical modeling codes, and inform related ALMA proposals to observe this molecule in protoplanetary disks. | Astrochemistry, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2019-12-14T14:56:11.000 |
| 3980 | 2021.2.00005.S | 547 | Millimeter photometry of the disks around Herbig AeBe stars | This is a simple, small survey program to obtain millimeter continuum and CO line fluxes for a well defined sample of disks around 51 nearby Herbig AeBe stars that have not yet been observed by ALMA. This short survey will reveal which disks are bright enough in the continuum and/or line for followup by the community and provide a near complete census (87 out of 91) of all known Herbig AeBe stars within 500 pc of the Sun. To encourage its broad and immediate utility, the data proprietary period will be waived and the flux measurements will be published within 6 months after data delivery. | Disks around low-mass stars | Disks and planet formation | 2024-07-05T16:29:07.000 |
| 3981 | 2016.2.00005.S | 222 | Spatial distribution of Phoshorus Nitride towards massive dense cores | Phosphorus (P) is a crucial element for the development of prebiotic chemistry. Despite this great relevance, little is known about the chemistry of P in the interstellar medium. Different theoretical pathways have been proposed to explain the gas-phase abundances of P-bearing molecules: gas-phase reactions at high temperatures vs. shock-induced desorption from grain mantles. Our group has previously detected the brightest P-bearing molecule, PN, towards 12 massive dense cores in different evolutionary stages (starless, protostellar and UCHII regions) using the IRAM 30m telescope. These single-dish data are not able to discriminate between the two competing models: while in some sources PN properties follow closely those of the shock tracer SiO (supporting the shock-induced scenario), in other sources the PN linewidths are too narrow and the excitation temperatures are too low to be explained by shocks. Only maps of the molecular emission of PN (compared with that of SiO) at high angular resolution will resolve this question. Therefore, we propose to map the 4-3 transitions of these two species with ALMA towards our sample. | High-mass star formation, Astrochemistry | ISM and star formation | 2018-10-04T15:09:58.000 |
| 3982 | 2017.1.00601.S | 278 | Can high velocity winds drive molecular outflows in main-sequence galaxies? | Outflows are a central element of galaxy evolution models. Observed ionised gas outflows are ubiquitous, but can the winds that drive them also launch outflows of cold, star-forming gas? We request 13 hours to map CO(1-0) in 16 main-sequence galaxies (0.02 | Spiral galaxies, Outflows, jets, feedback | Local Universe | 2019-03-26T16:11:11.000 |
| 3983 | 2015.1.00671.S | 30 | The Shape of Disk Irradiation: Imaging Molecular Dissociation Products in Nearby, Evolved Protoplanetary Disks | The powerful high-energy radiation fields characteristic of young,solar-mass stars should be of fundamental importance in determining the timescale over which, and the conditions out of which, exoplanets and their atmospheres emerge. However, observational evidence of the consequences of such stellar irradiation on outer disk regions remains elusive. We propose to obtain subarcsecond ALMA observations of C2H, CN, and HCN in the molecular disks orbiting the nearby, young solar analogs V4046 Sgr and T Cha. We will take advantage of the large angular radii and contrasting inclinations of the V4046 Sgr and T Cha disks --- both of which may already harbor young planets --- to establish the radial and vertical distributions of these potential molecular tracers of disk irradiation and gas-grain processes. The results will provide much-needed constraints on models for the production of dissociation products within molecular disks, by establishing whether the abundances of C2H and CN are enhanced in disk surface layers that are readily exposed to stellar UV and X-ray emission, or are instead generated deep within the disk, via pure gas-phase and/or gas-grain processes. | Disks around low-mass stars | Disks and planet formation | 2018-03-02T15:12:21.000 |
| 3984 | 2024.1.00929.S | 0 | Peering into the shadows: resolving the kinematics of dust-obscured quasar host galaxies at cosmic noon | We propose to perform a thorough CO(5-4) morpho-kinematical investigation of two heavily dust-obscured quasar host galaxies at z=2.5 and 3.2, to study the galaxy evolutionary transition from dusty star-forming galaxies to optically bright quasar host galaxies. High-z dust-obscured AGN hosts show the compactness of the optically bright quasar population and the exceptionally CO broad emission lines indicative of AGN-driven outflows or late stage mergers. By observing two compact heavily dust-obscured quasars at the cosmic noon, ULASJ1234+0907 at z=2.5 and W0149+2350 at z=3.2, with exceedingly broad CO emission lines (~900-1000 km/s), we can probe this evolutionary transition. We propose to observe the CO(5-4) emission of the host galaxies at ~<0.8kpc resolution to model the kinematics and characterise the potential outflows, and to observe at low ~8kpc resolution to determine the diffuse extended medium and its properties. Allowing us to detail the baryonic processes of these fascinating galaxies and bringing us a vital step towards clarifying how and if galaxies transition from dusty star-forming systems into optically bright quasar dominated systems. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-10-15T10:11:24.000 |
| 3985 | 2019.1.01218.V | 0 | Magnetic field structure in the jet acceleration and collimation zone of quasar 3C273 | High Faraday rotation measure of 5.0 x 10^5 rad/m^2 has been recently observed in the nearby radio-loud quasar 3C273 within ALMA Band 6. This has opened up a new window for studying the magneto-ionic medium in and around the jet base in active galactic nuclei. Here we propose one 8-hr long track of Band 6 VLBI observations of 3C273 with the EHT+ALMA array in order to make the first ever map of in-band Faraday rotation at 1.3mm. Our aim is to constrain the spatial distribution of the high rotation measure plasma in and around the jet base at a resolution of 100 Schwarzschild radii. The proposed observations would provide constraints on the poorly known magnetic field structure in the jet acceleration and collimation zone. For example, if significant gradient in the Faraday rotation measure in direction transverse to the jet is seen, this would provide strong evidence for the existence of an ordered toroidal magnetic field component. Furthermore, observing Faraday rotation measure from the jet acceleration and collimation zone provides a way to make more direct comparisons with the magnetohydrodynamic jet formation simulations than what is possible through emission maps. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-07-18T07:11:35.000 |
| 3986 | 2021.1.01340.S | 21 | Probing the extremes of the cloud-scale dense-gas star formation relation | There is great interest in complementing detailed studies of the initial conditions of star formation in local (Galactic) Giant Molecular Clouds (GMCs) with observations of GMCs in nearby galaxies, to probe a wider range of environmental conditions. Beyond observations of molecular transitions of CO and isotopologues, ALMA is enabling resolved observations in nearby galaxies of molecular transitions with high critical densities. This is particularly relevant for HCN(1-0), since it is integral to the empirical dense-gas star formation relation, a correlation with the star formation rate (SFR) that has been observed both locally and for entire galaxies. Recently, it has become clear that in local GMCs, our understanding of HCN excitation is complicated by the presence of HCN emission beyond the highest densities, on scales of several pc. To study the resolved dense-gas star formation relation and look for such extended HCN emission, we propose to target 3 massive GMCs in M33 whose SFRs could hardly be more different, including the extreme HII region NGC 604 and quiescent GMC-8. Previous pc-scale ALMA data in 13CO(2-1) guide and enable the detection of HCN (and more) on these scales. | Inter-Stellar Medium (ISM)/Molecular clouds, HII regions | ISM and star formation | 2024-01-12T23:36:55.000 |
| 3987 | 2016.1.01040.S | 474 | A [CI] survey of high-redshift main-sequence galaxies | State-of-the-art modeling shows that the atomic carbon line [CI](1-0) is a much better tracer of gas mass (Mgas) than CO(1-0) and [CII], being almost insensitive to density and radiation field variations. However, the only objects currently detected in [CI] at high-redshift are lensed starbursting sub-mm galaxies and quasars, completely missing the bulk of the normal main-sequence (MS) population. To fill this gap, we ask for 8h of ALMA time to follow-up [CI](1-0) in ~50 MS galaxies at z=1.2. Observations in [CI](2-1) are requested for a subsample of 8 targets. The combination of [CI](1-0) and (2-1), continuum emission at 500 mum rest-frame (a bonus from our observations), COSMOS's excellent photometric and IR coverage, spectroscopic redshifts, and in-hand CO(5-4) observations will allow us to securely estimate gas masses and fractions (Mgas, fgas), the excitation conditions of the ISM (from the [CI](2-1)/(1-0) ratio), star-formation rates, and stellar masses. Comparison with totally independent estimates of Mgas from CO and dust emission will provide crucial insight into the highly disputed evolution of fgas and star formation efficiencies with redshift, along and off the MS. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2018-04-05T17:32:27.000 |
| 3988 | 2011.0.00511.S | 0 | Mapping Shock Chemistry in NGC 1266: Local Example of AGN-driven Feedback | NGC 1266 is an S0 galaxy that was observed in multiple wavelengths as part of the Atlas3d effort which remarkably hosts 10^9 solar masses of molecular gas and has a spectrum that exhibits extended wings of up to +/-400 km/s. High resolution CARMA observations have shed further light on this galaxy and revealed that the bulk of the gas is concentrated within 100pc of the nucleus, The presence of an AGN combined with molecular gas outflowing faster than vesc hints that this galaxy might be a local candidate for AGN feedback. The fact that the SFR is unable to support such a high energy outflow strengthens this claim. NGC1266 is the first example of molecular feedback into the IGM from a relatively normal, non-interacting galaxy. How the gas fell so deeply into the potential well, and the exact nature of the driving mechanism behind the expulsion of the gas remain mysteries. We propose to use ALMA to map five transitions of SiO in NGC 1266 to obtain spatial, velocity, and excitation information, enabling us to study the shock-molecular gas interface, and possibly shed light on AGN-driven molecular gas expulsion. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2013-11-15T15:43:00.000 |
| 3989 | 2021.2.00019.S | 0 | Large-scale starburst activity in the Early Universe: Locating the fuel for star formation | We propose deep 7m+TP array observations of [C I] 1-0 emission towards two massive galaxy clusters at z>=4, where ALMA has demonstrated that extraordinarily intense starburst activity occurs in numerous (N>10) galaxies separated by hundreds of kpc. Existing interferometric data are insensitive to inter-cluster scale gas. The proposed observations will reveal the true extent of the gas supply fueling these starburst events. Combining the ACA data proposed here with archival 12m-array data, we will infer the mass of protocluster-scale molecular gas, and its distribution, searching for filamentary/tidal structures. The [C I] line can trace CO-dark gas, expected to be prevalent in protocluster environments where energetic particles influence the astrochemistry more than photons. Locating a massive, widely distributed gas reservoir via [C I] would resolve the puzzle of how numerous colossal starbursts occur simultaneously - as if coordinated - across hundreds of kpc. These observations represent the first step towards imaging the cold cosmic web at z=4 with ALMA, revealing crucial information on the fuel for star formation in the densest environments at early cosmic epochs. | Starburst galaxies, Galaxy Clusters | Active galaxies | 2023-07-05T18:58:23.000 |
| 3990 | 2016.1.01375.S | 30 | Searching for the flow base of the disk wind in TW Hya | Disks around young stellar objects are the birthplaces of planetary systems and have typical lifetimes of a few million years. The lifetime of disks defines the timescale on which planet formation can occur. However, the process responsible for disk dispersal is not completely understood. A possible mechanism are photoevaporative winds, driven by the high energy radiation of the star (UV, EUV and/or X-rays). With this proposal we aim to observe an alternative tracer of disks winds, namely the Carbon monoxide ion (CO+). CO+ resides a the very bottom of the atomic layer and above the CO layer of the disk. The location of CO+ makes it an excellent candidate to observe the flow base of disk winds (in contrast to atomic line tracers originating in the uppermost surface layers). We propose to observe CO+ emission in the disk of TW Hya which shows an observationally confirmed slow ionized disk wind, aiming to detect the flow base of this wind and provide strong constrains on the radial and vertical extension of the flow and the wind mass loss rate. | Disks around low-mass stars | Disks and planet formation | 2017-12-20T14:38:09.000 |
| 3991 | 2019.1.01722.S | 168 | Spectroscopic identification of a pilot sample of two hot dusty starbursts at z~4 hidden at 850um | Deep field imaging surveys at far-infrared (FIR) and millimeter bands have greatly enriched our knowledge of the distant universe by discovering a population of extremely dusty galaxies. There is a growing evidence of a rising dust temperature toward high redshifts, with galaxies at high redshifts (z>3-4) have hotter characteristic dust temperatures, compared to similar FIR luminous galaxies at z~2. New simulation results suggest that the hotter z>3 systems would be young galaxies at the early evolution phase with higher star-formation efficiency, the bulk of which still remains undetected in the typical surveys at 850um. We propose to spectroscopically confirm two 450um-bright but 850-faint dusty galaxies at z~4 that are drawn from our latest deep survey at 450um, likely representing the missing population of the hot galaxies. The observations will also allow to estimate effectively the molecular gas content to uncover the nature of hot dust emission and constrain the ISM properties through multiple CO lines. This observation will also serve as a benchmark for future follow-up observations with ALMA and JWST towards a more complete sample. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2021-02-04T01:56:43.000 |
| 3992 | 2017.1.00181.S | 40 | Primordial Multiplicity at Massive Star Birth | [Resub. of approved Cy. 4 project] ALMA now has the ability to see fine details around massive protostars. Observing continuum/lines at 1.3mm, we aim to detect substructure, especially multiplicity, disk & outflow features, in 8 massive protostellar cores at scales down to ~60 AU. This sample is part of a larger MIR/FIR survey with SOFIA. Radiative transfer models are being utilized to test geometries of dust structures, especially outflow cavities. We observed these 8 sources with ALMA in Cycle 3 from 10" to 0.14" scales, i.e., to ~300AU. Observations proposed here will be combined with those from Cycle 3 to give the highest spatial dynamic range possible. We also observed all 8 sources with HST in Cycle 23. One goal is to detect jet/outflow knots at ~0.15" resolution. These may show high proper motions of ~0.14"/yr, so it is desirable for the high-res ALMA observations, which may also detect these features, to be executed as soon as possible to minimize proper motion drift. Overall, the results of this project will provide powerful tests of massive star formation theories, as these make widely varying predictions on the degree of primordial multiplicity & substructure. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2019-01-27T14:05:12.000 |
| 3993 | 2021.1.00115.S | 20 | Locating the position of the midplane water snowline in protoplanetary disks around young bursting stars | We propose to observe the water lines at ALMA Band 7 towards protoplanetary disks around young bursting stars, V883 Ori and EC 53. Accretion burst is thought to be important in terms of thermal history of materials in planetary systems, including the Solar System. The burst phenomena will affect the water snowline location, distribution of water-containing solid materials, and also composition of organic molecules in the disk. The target water lines that trace the water snowline location were selected carefully based on the detailed chemical disk modeling, since water gas exists not only inside the snowline but also in the outer disk. By analyzing the line profiles under an assumption of Keplerian motion, we will be able to locate the snowline spectroscopically even without spatially resolving the line emitting region. One of the target lines of HDO was marginally detected previously. Meanwhile, some complex organic molecular lines including CH3OH have been detected towards these objects recently. Our proposed observations will obtain essential information on the planet formation process and the origin of water and organic molecules on Earth. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2023-12-22T20:09:52.000 |
| 3994 | 2015.1.00658.S | 4 | Comparing Morphology and Kinematics of Warm CO with Warm Molecular Hydrogen in Star-Forming Galaxies | A fundamental assumption of analyses of CO emission to date has been that CO emission traces molecular hydrogen over the entire range of physical conditions in the observed sources. However, a direct observational comparison of the spatial distributions and kinematics of CO and H2 emission has not been made for the warm, high-pressure molecular gas that dominates the CO luminosity in galaxies, to assess the extent to which they trace the same molecular gas. We propose to make such a comparison for the first time by observing the warm CO emission (traced by the J = 6-5 line) using ALMA and warm H2 emission using SOFIA for NGC 253, NGC 1068 and NGC 6240. NGC 1068 has already been observed and thus is not requested in this proposal. The diversity in the physical conditions of these targets will enable us to investigate variations in the CO and H2 emission in different environments. Our SOFIA proposal is already approved. The H2 lines will provide independent measurements of temperature and column density, which will be compared with the gas physical conditions derived from non-LTE modeling of the CO lines, in addition to direct comparison of the spatial and velocity distributions. | Starbursts, star formation | Active galaxies | 2020-10-27T00:00:00.000 |
| 3995 | 2018.1.01079.S | 100 | HST-Dark galaxies in the GOODS-ALMA field | One of the most uncertain and potentially transformational outputs of ALMA is its ability to reveal a new class of galaxies through serendipitous detections. This is also one of the main reasons for performing blind extragalactic surveys which can provide a complete view on this new parameter space, specific to ALMA. The present proposal targets a systematic identification of serendipitously found HST-dark galaxies in the GOODS-ALMA field to obtain or confirm spectroscopic redshifts from their CO lines. With their ultra-faint optical properties, this is the only way to determine whether there is really a 20% population of new, highly obscured galaxies in the distant Universe or whether these galaxies are actually nearby galaxies or regions of their neighbors but with abnormally low dust temperatures. With this proposal of 10h, we will (i) determine or confirm the redshifts of these sources, (ii) derive their molecular gas content, (iii) deduce their star formation efficiency. We will determine if these galaxies are observed during a starburst phase, determine whether they possess abnormally large molecular gas reservoirs and compare their CO conversion factor to that of. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2020-09-13T22:29:18.000 |
| 3996 | 2015.1.01136.S | 10 | Detecting [CII]emission from a strongly lensed galaxy at the end of the reionization epoch. | Confirmation of galaxy candidates at z>6 has proven hard due to the apparent lack of strong Ly-a emission generally. And even for rare cases where redshifts have been secured, the objects remain hard to study in detail. An alternative approach is to target the prolific [CII] line, which has already led to some detections at z~4.7-6. However, in parallel, several [CII] searches at z>6.5 have ended in non-detections, thereby giving us a mixed picture at high redshift. Here we propose a deep search for [CII] in a lensed galaxy at z=6.027. We observed this galaxy in cycle 1 and failed to detect [CII], placing upper limits on the [CII] luminosity which are a factor of >2 below expectations, based on [CII] detections in galaxies with similar SFRs and redshifts. This result is already at odds with the SFR-[CII] luminosity relation found at low redshift, but leaves much unanswered about the potentially widening parameter space at z>6. We request a longer observation to either detect [CII] and confirm its usage as an alternative to study high redshift galaxies, or result in a deep non-detection that will reveal the existence of galaxies where [CII] is not a valid alternative for study. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2018-03-21T06:10:34.000 |
| 3997 | 2017.1.01018.S | 36 | A high-resolution look on [CI](2-1) and CO(7-6) in 2 lensed SPT galaxies: extended gas reservoirs or compact starbursts? | Characterizing the gas reservoirs of dusty star-forming galaxies (DSFGs) is essential to determine if their impressive star formation rates are either due to their extended gas reservoirs or to compact starbursts. With the APEX/SEPIA instrument, which includes a prototype of the ALMA band 5 receivers, we observed a sample of lensed DSFGs from the SPT survey in [CI]2-1. This line is an alternative to CO to trace the gas, which is optically thin, not destroyed by cosmic rays, and less affected by the CMB. These observations revealed a large scatter of the ratio between [CI](2-1) and CO(7-6), which traces dense excited gas and is observed simultaneously. These results suggests very diverse ISM properties across our sample. To understand the origin of the [CI](2-1) and CO(7-6) emission and the nature of these galaxies, we propose a 5-h pilot program to observe our two most promising sources at high resolution (0.3 arcsec). With these data, we will: a) map the gas and dust in these two objects; b) study the variation of ISM conditions inside them; c) produce high quality lensing models and test the presence or not of differential lensing; d) determine their dynamical properties. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-10-02T08:57:05.000 |
| 3998 | 2021.1.01720.S | 10 | Benchmarking 13C fractionation with HC3N in protoplanetary disks | Isotope ratios (e.g. D/H, 12C/13C, 14N/15N) are powerful tools in the study of bodies within the Solar System, shedding light on questions such as the origin of the Earth's water reservoir. Connect these isotopic measurements to protoplanetary disks has proven difficult, however, with isotope fractionation studies limited by an unconstrained 12C/13C ratio. An ISM ratio of 69 is often assumed, but disk chemical modeling has shown that this value can be modified by factors of >5 by in-situ chemistry. Typical bright tracers (e.g. CO, CS, CN) are too optically thick in their 12C isotopologues to make a direct measurement, and weaker species (e.g. CH3CN) do not have strong enough 13C isotopologue emission. The first direct measurement of 12C/13C was recently made using HC3N observations toward the nearest disk TW Hya, showing that the disk 12C/13C ratio is substantially modified from the canonical ISM value. We therefore propose follow-up observations toward the second nearest disk, V4046 Sgr, to investigate whether it also has enhanced 13C fractionation. These results will have an immediate and broad impact on the disk community, improving D/H and 14N/15N fractionation constraints. | Disks around low-mass stars | Disks and planet formation | 2023-08-29T19:27:55.000 |
| 3999 | 2023.1.01710.S | 0 | Mapping the host galaxies of z=2 quasars | We propose high resolution (0.5") observations of the CO (3-2) line in four z=2 quasars with primary goal of tracing the connection between supermassive black holes (SMBHs) and their host galaxies. The ongoing upgrade of GRAVITY to GRAVITY+ is now able for the first time to dynamically measure the SMBH mass in high redshift quasars. Host galaxy information for these highly luminous quasars is difficult due to the quasar outshining the galaxy at most wavelengths. Molecular gas emission line observations can overcome this however and provide size, kinematic, and mass measurements. We have selected a sample of four quasars that are prime targets for GRAVITY/GRAVITY+ based SMBH mass and with CO (3-2) line detections from NOEMA. The proposed observations aim to map the CO (3-2) line emission to robustly measure the dyna | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2024-12-27T18:01:51.000 |
| 4000 | 2019.2.00232.S | 17 | Confront the idea of 3D projection effects of chemicals in a cold clump with high resolution mapping. | Asymmetrical distributions of molecule line emission around dense cores are frequently observed but hard to explain with chemical models that are based on a single spherical core. We recently have proposed the spatial projection effects of the 3D cloud structures to be a promising solution and have successfully applied this idea to a Planck cold clump G224.4-0.4. The 850um continuum and CCS, HC3N and N2H+ line maps were well interpreted with four independent cloud cores overlapping along the line of sight. Hereby we propose mapping with higher spatial resolution of carefully selected molecular lines and continuum tracers in Band 6 to the same clump to further test our multiple-core chemical model and to improve the model parameters. The 3D projection effects could be very common in molecular clouds and this project will provide the first ever high spatial resolution data set to elaborate this idea. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-04-24T15:25:41.000 |
| 4001 | 2015.1.01345.S | 8 | Spatial Strucutre of the Brightest Unlensed Submm Galaxies | Distant SMGs represent the most massive of the young galaxies rapidly building up their mass in the early universe. Their importance in terms of understanding the cosmic stellar mass build-up history is amplified if they represent the pinnacle of the ``cosmic downsizing'' phenomenon. Here we propose to investigate detailed spatial distributions of dust in the intrinsically most luminous SMGs as a direct test of how such extreme starbursts can be fueled and sustained. We request 6.7 hours of ALMA Cycle 3 time in band 7 at 0.04 arcsec resolution. As demonstrated by our simulated observations of the Antennae galaxies, the high angular resolution and high sensitivity possible with ALMA Cycle 3 are required to address this question properly, and only the most intrinsically luminous SMGs can be studied this way even using ALMA. Whether mergers or cold flow accretion, the knowledge we will obtain through this experiment on the process responsible for supplying large quantities of material over a short period of time to these SMGs will also serve as a key process feeding the bulk of the stellar mass build up process among the less luminous starforming galaxies at the same epochs. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-02-23T04:58:23.000 |
| 4002 | 2019.1.01443.T | 9 | Massive Planets and Debris Discs: How do Planetary Systems evolve in the presence of Multiple Massive Planets | We propose to image the debris disk of the ~nearby (30.1pc) >2.5Gyr-old sub-giant KIV star kCrB in band 6 to determine the disk structure at 1.5" resolution, >7 times better than previous observations. This system hosts an Exo-Jupiter planet at 2.8au and a second massive planet (>2MJup) on a wide-orbit (a>15.8au), as well as dust disk. The proposed images will determine the architecture of the planetary belt and the radial distribution of material, which is likely being strongly influenced by the outer massive planet. Models are in place to interpret the observed structure in terms of unseen planets in the outer regions, their formation and evolution. Whilst no strong correlations have been found to exist between systems with Exo-Jupiters and those with debris belts, this has yet to be tested in detail for a system with a bright known dust belt with close-in and wide-orbit massive planets. The proximity, sub-mm brightness and mass of kCrB make it uniquely placed for studying planetary systems in the presence of multiple massive planets. Additionally, we will search for CO J=2-1 line emission within the disk, which if found would be the oldest CO Gas ever detected in a debris belt. | Debris disks | Disks and planet formation | 2021-07-06T11:34:03.000 |
| 4003 | 2022.1.00991.S | 10 | High-resolution observations of jet-ISM interactions in nearby mature radio galaxies | Evidence has accumulated that kinetic (jet-induced) AGN feedback can significantly affect the physics and kinematics of the cold gas on (sub-)kpc scales. Detailed studies of jet-cold gas interactions, however, are currently limited to few objects, mostly nearby Seyferts hosting young and powerful radio jets. We hereby target two nearby mature radio galaxies with large-scale, low-power jets: NGC 3557 and IC 1531. The incidence and impact of jet-induced perturbations on the gaseous medium of objects of this kind is not yet clear. Previous ALMA CO(2-1) data provide indications for the presence of jet-cold gas interactions in our targets, but their poor spatial resolution does not allow to carry out a detailed analysis and draw solid conclusions. With this proposal, we aim at re-observe the CO(2-1) line at four (NGC 3557) and seven (IC 1531) times higher resolution, probing spatial scales of 30 and 50 pc for NGC 3557 and IC 1531, respectively. This will allow us to separate perturbed and quiescent gas regions, carry out a detailed CO kinematic modelling and put crucial constraints on how the jet-gas coupling changes over time. | Outflows, jets, feedback, Early-type galaxies | Active galaxies | 2024-06-19T14:33:28.000 |
| 4004 | 2022.1.00887.S | 0 | Ultra-High Velocity Resolutions of the Planet-Disk Interactions in TW Hya | TW Hya has been found to display a stunning array of kinematic structures, including a large, tightly wound spiral and, using new, unpublished archival data, a signature reminiscent of a 'Doppler flip' within the wide gap at 90au observed in scattered light. The complexity of these velocity features are highly indicative of on-going planet-disk interactions, and point to a Saturn mass planet residing the 90au gap. Unfortunately, the line-of-sight projection of the velocity components hinders the full interpretation of the kinematic features. This proposals therefore aims to leverage the unparalleled ultra-high velocity resolution of 13m/s afforded by Band 9 observations to search for the highly localized non-thermal motions associated with infall onto and/or rotation of the planet-circumplanetary disk system. The detection of enhanced velocity dispersions coincident with the Doppler flip will provide crucial anchor points for interpreting the complex large-scale velocity structures associated with the embedded planet, in addition to allowing an exquisite characterization of the vertical dependence of planet-driven kinematic features, a crucial test for numerical simulations. | Disks around low-mass stars | Disks and planet formation | 2024-10-24T19:45:58.000 |
| 4005 | 2017.1.00716.S | 933 | A survey of prestellar, high-mass clump candidates: constraining models of high-mass star formation | The lack of a significant amount of prestellar, high-mass cluster-forming clumps has made hard to conclusively refute or support models of high-mass star formation. In addition, the insufficient sensitivity and angular resolution have done challenging to unambiguously test observational predictions. In our pilot survey, we dectect no high-mass prestellar cores, the more massive cores (<16 Msun) are subvirialized, and surveys that only make single-pointing observations are highly imcomplete. Expanding on our pilot survey, we aim to observe a complete sample of prestellar high-mass clump candidates with masses >500 Msun, temperatures <16 K, distances <5 kpc. All our targets are IR-dark up to 70 um. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-09-15T09:12:51.000 |
| 4006 | 2015.1.00823.S | 1 | A deeply buried AGN? Zooming in on the nucleus if the LIRG IC860 | We propose high resolution (13 pc) Band 7 imaging of the exceptionally luminous emission from vibrationally excited HCN v2=1f J=4-3 (HCN-VIB) in the LIRG IC860. The goal is to map the hidden mid-infared nucleus traced by the HCN-VIB line and determine if the extremely obscured nucleus is powered primarily by an accreting supermassive black hole (SMBH) - or by a rapidly growing stellar spheroid. The ground state HCN and HCO+ lines (standard high density gas tracers) are self-absorbed and cannot be used to probe the structure and dynamics of the buried nucleus. The HCN-VIB line can probe inside the opaque layers since it requires intense bright mid-IR continuum emission to be excited and is a proxy for extremely high mid-IR surface brightnesses >5e13 Lsun/kpc2. We will use the HCN-VIB line to resolve the hot nucleus and to probe its morphology, clumpiness, orientation and dynamics with the ultimate goal to address the nature of the power source. IC860 is a representative of a class of of deeply obscured galaxies where the opaque nucleus is in a state of rapid growth. The buried activity in these Compton thick (CT) nuclei may be missed by both X-ray and mid-IR surveys. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2019-01-22T15:34:02.000 |
| 4007 | 2013.1.00362.S | 10 | The Assembly Line of Normal Galaxies: the Direct Detection of the Dusty Phase of Star Formation at z~3 | We propose a direct detection experiment of the 850um dust continuum emission in a pilot sample of 10 `typical' z~3 Lyman Break Galaxies (LBGs). LBGs are much more ubiquitous and `mainstream' than the more extreme submm galaxies (SMGs), and so are thought to be the progenitors of `normal' galaxies, such as our own Milky Way Galaxy, giving rise to a significant part of the stellar population in today's galaxies. Until now, we have had a very incomplete picture - recent work has given us a statistical detection of the obscured star formation (which is comparable to or even dominates over the unobscured star formation even in these UV-selected galaxies), and only now with ALMA will we be able to fully characterize the SEDs of individual `typical' run-of-the-mill galaxies in formation, providing: 1) an unbiased measure of the dust obscuration in these systems to compare against the UV-inferred star formation rates, and 2) a probe of the level of activity in LBGs across the merger sequence to test our theoretical picture of galaxy assembly as well as providing a comparison test with the rate of mergers in more massive populations (such as SMGs). | Lyman Break Galaxies (LBG) | Galaxy evolution | 2016-09-23T19:28:28.000 |
| 4008 | 2023.1.00390.S | 0 | Exocometary volatile delivery in the inner regions of the Eta Corvi system | Thanks to an ALMA discovery in cycle 1, Eta Corvi became the first and only extrasolar system with evidence for ongoing delivery of volatile rich bodies to the terrestrial planet region of a system. This hosts the brightest known exozodi (short-lived warm dust around 1 au that is found around 20% of nearby stars), which is replenished by material formed further out in its cold planetesimal belt imaged by ALMA at 150 au. The previous ALMA observations revealed CO gas present in this system at 20 au, which is likely released by volatile-rich exocomets formed in the outer belt as they get closer to the inner regions of the system, and also feeding the warm dust within 1 au. Here we propose to do a follow-up study with greater sensitivity and resolution to: i) measure the total mass, radial profile and release rate of CO gas; ii) constrain the dynamics of exocomets using the velocity information in the CO line; iii) constrain the architecture of the chain of planets scattering exocomets; iv) search for atomic carbon produced by CO photodissociation, which will indicate for how long this scattering has been going on and if gas could increase the exozodiacal dust lifetime. | Debris disks, Solar system - Comets | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 4009 | 2021.2.00097.S | 154 | CLOAK: unCovering Lupus brOwn dwArfs bulK emission | The formation mechanisms of substellar objects are still under debate. Systematic studies in nearby molecular clouds are needed to shed light on how these objects form. Lupus is an excellent laboratory to study the formation mechanisms of substellar objects. Our sample is based on a previous ALMA 12-m study of compact very young brown dwarfs candidates that were not able to detect extended emission of the envelopes. We propose continuum observations at 1.3 mm using the ACA in standalone mode towards twelve pre-brown dwarf candidates and two Class 0 brown dwarf candidates found in Lupus 1 and 3. Our main aim is to characterize the dust envelope surrounding these substellar objects to study their energetic status and shed light on the formation mechanism. As a secondary goal, we aim at detecting gas emission surrounding these objects, which would help to better determine their energetic state, kinematics, and the expected outflows in the more evolved sources. This proposal will provide important insight into the formation of brown dwarfs. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2024-02-01T12:14:42.000 |
| 4010 | 2012.1.00320.S | 0 | Molecular and ionized tori in the bipolar planetary nebula NGC 6302 | NGC 6302 is a remarkable planetary nebula (PN) with a butterfly shape. There are many indirect evidences that this object is multi-polar shaped confined around a warped disk/torus, which is similar to the structure predicted by the hydro-dynamical simulation of disk-wind interaction. We propose the ALMA observations to capture the geometry and the velocity structure of the disk/torus. We propose line observations of both ionised lines (H30alpha) and molecular lines (13CO, C18O and SO). The high angular resolution (0.9") and sensitivity of the ALMA will provide the first opportunity to reveal that the disk is actually the warped shape, because the spatial resolution is directly compatible to the hydro-dynamical simulations, and observations of multi-lines can show the hierarchal structure within the disk. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-12-10T14:53:51.000 |
| 4011 | 2013.1.01366.T | 0 | Impacts of a global dust storm on Martian atmosphere | The most striking phenomenon on Mars is a planet-encircling storm, so-called "Global dust storm". Once it occurred, dust covers the whole atmosphere, and heats the atmosphere via absorption of solar radiation for more than one month. Our simulations predict that atmospheric temperature rises more than 20 K at 10-60 km altitude over the planet under the dust storms. Such a drastic heating in the atmosphere induces water vapor to remain without condensation, and accelerates dynamics. Moreover, Atreya et al (2006) predicted the amount of H2O2 could increase due to triboelectric filed under a global dust storm. The goal of this proposal is to evaluate how much change is induced in thermal structure, dynamics, water vapor abundances, and H2O2 amounts due to a global dust storm. We propose simultaneous observations of CO, HDO, and H2O2 using the ALMA band-7 during/after a global dust storm as a ToO observations. Through conscious monitoring of dust opacity by Mars Express spacecraft, we can trigger to carry out the observation in real-time. A new sensitive observation of dust-covered Martian atmosphere with ALMA will provide essential understanding in the Martian meteorology/climate. | Solar system - Planetary atmospheres | Solar system | 2017-01-22T15:04:53.000 |
| 4012 | 2016.1.00912.S | 38 | ALMA Mapping of a Great Case of Ongoing Ram Pressure Stripping in the Nearby Virgo Cluster | We propose to map CO(2-1), CO(3-2) and 870um continuum in the spiral NGC~4402, one of the best cases of active ram pressure stripping in the nearby Virgo cluster. HST images reveal a remarkable variety of ISM features associated with ongoing stripping that we would like to characterize, including kpc-scale head-tail filaments, small decoupled clouds, ablated extraplanar dust plumes, several-kpc-long extraplanar dust fronts, and leading edge star-forming complexes. We will measure cloud sizes, linewidths, masses (gas and dust), and CO(3-2)/CO(2-1) ratios, and compare cloud properties with various nearby galaxies, to learn whether the clouds which appear to be affected by ram pressure have distinct properties. We can determine the cloud mass function and its spatial variation, to explore whether ISM compression along the leading edge results in more massive clouds, and estimate the fraction of the ISM mass that decouples during stripping. Comparison of simulations with these detailed observations of gas being stripped from the disk will give us a better understanding of the efficiency of stripping, and therefore its impact as a quenching mechanism throughout the universe. | Spiral galaxies, Galaxy groups and clusters | Local Universe | 2019-10-15T00:00:00.000 |
| 4013 | 2021.1.01116.S | 67 | Chemistry in Feedback Environments in the Early Universe | Feedback is thought to be one of the main processes regulating star formation in its peak phase throughout the history of the universe. We here propose to use the key oxygen hydrides, OH+, H2O+, and H3O+, to probe the molecular ion chemistry associated with outflowing and infalling gas vs. the material found at the active sites of star formation. Based on state-of-the art chemical modeling, we will measure abundances and column densities, as is critical to calculate mass/momentum outflow/infall rates and the local physical conditions in the absorbing layers. We will also study variations in the gas density in the gas flows vs. systemic gas components, molecular fractions, and fractional ionization. We will link these findings to the star formation rates and their surface densities to search for spatially-resolved correlations. These measurements will be key to understand the nature of the turbulent gas entailed in the large-scale outflows and infall associated with massive galaxies in the early universe in their peak starburst phase, and how they impact the resulting stellar population seen in their present-day counterparts at the end of the mass buildup process. | Starburst galaxies | Active galaxies | 2023-07-25T18:41:48.000 |
| 4014 | 2019.1.01423.S | 6 | Star Formation and the Turbulent Interstellar Medium of Lyman Break Galaxy Analogs | A major challenge for studies of galaxy evolution is understanding the details of star formation in key populations at all redshifts. While Lyman break galaxies (LBGs) at z>3 have been studied extensively, their dense gas reservoirs remain poorly understood due to limited sensitivity and resolution. Exploiting the proximity of z~0.2 LBG analogs (LBAs) and close engagement with theory, we propose to obtain 0.2" resolution CO(3-2) line observations to address three key questions that are difficult or impossible to tackle directly at high redshift. First, we will analyze LBAs' molecular gas kinematics to assess whether gravitational instability or star formation feedback drives the turbulence that dictates the collapse of clouds to form new stars. Second, we will determine whether and how LBAs diverge from the global and resolved Kennicutt-Schmidt relation seen in ordinary star-forming galaxies at z=0. Third, we will investigate whether and how shocks and star formation feedback impact the molecular gas reservoirs of LBAs. | Starbursts, star formation | Active galaxies | 2022-08-17T20:48:20.000 |
| 4015 | 2018.1.01440.S | 178 | A search for compact carbon emission from UV active AGB stars | To better trace the enrichment of the interstellar medium by outflows of evolved stars, it is critical to understand the chemical networks active in them. Large parts of the circumstellar envelopes (CSEs) are dominated by incident UV photons, which can efficiently photodissociate molecular gas, releasing atomic species. The best-known source of UV radiation is the interstellar radiation field (ISRF). Additionally, recent GALEX observations mark the presence of an internal source of UV emission in 180 AGB stars. This additional UV flux could drastically change the chemistry in the CSEs, but is not yet considered in chemical models. Observations of UV-photodissociation products, such as CI, can probe the effect of an internal UV source. The recent detection of a compact CI emission region around omi Cet, a UV-bright source, indeed supports this approach. We propose to observe CI emission in a sample of 8 of these UV-bright asymptotic giant branch stars to further test the hypothesis that these would have a significantly enhanced CI-abundance close to the star as a consequence of photodissociation by the internal UV source. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2020-07-15T14:01:11.000 |
| 4016 | 2012.1.00919.S | 0 | Probing molecular gas in low-z analogs of primordial galaxies | Molecular gas, dust, and metallicities of star-forming galaxies give us crucial information for understanding the star formation and chemical enrichment processes in galaxies. Despite tremendous efforts, however, detecting CO in metal poor galaxies has been extremely difficult and there have only been a handful of measurements. Here we propose to break the current observing limitations with the superb sensitivity of ALMA and measure CO emission from so-called "CO-dark", low metallicity galaxies. Our sample consists of three star-forming metal poor galaxies ($Z < 0.3$ $Z_{\rm sun}$) at low redshift ($z\!\sim\!0.3$) with very recent starburst ($<$ a few Myr). They are considered to be the low redshift analogs of the first generation of galaxies in the Universe, and thus provide insight into the early phase of star formation. Our galaxies are located within the COSMOS field, where a wealth of multi-wavelength datasets allows us to study the galaxies in great detail. Together with existing $Spitzer$ and $Herschel$ data, the proposed ALMA observation will further constrain the CO to IR luminosity ratios for these metal poor galaxies. Our ultimate goal is to measure CO in low-metallicity environments and investigate the effects of metallicities on CO-to-$\rm H_2$ conversion factor, $\alpha_{\rm CO}$. Because of the cosmic evolution of the mass-metallicity relation, accurate knowledge of $\alpha_{\rm CO}$ at the low-metallicity end becomes highly important at higher redshift for measuring the total molecular gas from CO observations. The results from the proposed observation will give a better understanding of star formation process in early stage of galaxy formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2015-04-25T18:30:18.000 |
| 4017 | 2013.1.00048.S | 0 | Physical properties of an accretion disk around Orion Source I | We propose high resolution multi-transition observations of vibrationally excited H2O lines in a circumstellar disk around a massive YSO Source I in Orion KL. In ALMA cycle 0, we detected a vibrationally excited thermal H2O line at 336 GHz (excitation energy of 2939 K) for the first time in Source I. The velocity centroid map of the 336 GHz line is elongated with a size of 0.2". Most importantly, it shows a clear velocity gradient perpendicular to a bipolar outflow, implying a rotating ring-like structure with an enclosed mass of 7 Solar masses. The spectral profile can be reconciled with an excitation temperature of >3000 K possibly heated via accretion. However, due to the limited resolution (0.4"), derived parameters would contain large uncertainties. Moreover, the temperature of the H2O gas could not be obtained by excitation analysis due to a lack of multi-transition data. Vibrationally excited thermal H2O lines can be unique tracers to reveal the hot molecular disk around Source I. Our observations will allow us to derive its detailed properties such as size, mass, temperature, density, and H2O abundance, which are crucial to understand accretion processes in the disk. | High-mass star formation | ISM and star formation | 2017-11-04T20:42:17.000 |
| 4018 | 2021.1.01172.S | 0 | Spatially resolved observations of the 14N/15N isotopic ratio in Herbig disks | Isotopic ratios are often used to determine the formation history of the organic material in our solar system. Observations of the disk-integrated N fractionation ratios in 7 protoplanetary disks have found fractionation ratios between 80 and 200, very similar to cometary values (~100-250). However, only two disks have been observed at high enough angular resolution to resolve the fractionation profiles. Both disks have been around T Tauri stars. Disks around intermediate mass stars, Herbig Ae, present higher UV fluxes and disk temperatures, that could potentially affect the N fractionation patterns. We propose to spatially resolve (0.2'') the 14N/15N ratio in HCN across two disks around Herbig Ae stars: MWC 480 and HD 163296. HC15N has already been detetected in both disks making them prime candidates for follow up observations, but only at 0.5'' angular resolution. With the proposed observations we will be able to directly compare the N fractionation in disks around T Tauri and Herbig stars, and test current chemical models of nitrogen isotope fractionation. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2023-10-21T17:08:00.000 |
| 4019 | 2017.1.01605.S | 6 | Resolving the launching of the DG Tau B outflow | The mass accretion phase of star formation is accompanied by powerful bipolar ejections of still unknown origin. The exact origin of jets and outflows, their role on mass and angular momentum extraction as well as their impact on proto-planetary disk evolution remain as major unsolved issues in modern astrophysics. Our team has recently obtained ALMA observations on the bright Class 1 Taurus target DG Tau B. This source is our current best opportunity to test the MHD disk wind paradigm and directly study the connection of outflows with the underlying disk. We propose to map the central regions of the disk-outflow in the prototypical Class I target DG Tau B at 0.05$^{\prime\prime}$ angular resolution (7 au) in the continuum and in the $^{12}$CO(2-1) line at 230 GHz. These observations will allow to directly map the launching of the CO cavities and will provide a unique opportunity to relate disk structure and outflow launching in a protostellar source.Combined with our previous Cycle 3 data, they will also provide the first comprehensive view of the disk-outflow connection in a protostar from 7 au to 1000 au scales. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-01-27T13:59:17.000 |
| 4020 | 2022.1.00115.T | 122 | Rapid ToO Observations of Nearby Supernovae: Probing The Final Evolution of Massive Stars | Recent observations of core-collapse supernovae (CCSNe) have led to a surprising picture that the massive stars are much more dynamic in the last few years than widely accepted previously; dense circumstellar matter confined in the vicinity of the progenitor (confined CSM) has been inferred. However, the optical emission is biased to pick up extreme CSM with large uncertainty in the interpretation. A quick ALMA ToO will yield unique and unbiased diagnostics. There are only three previous examples for which the nature of the confined CSM has been derived, using the ALMA data within ~5 days since the explosion. Contrary to the previous expectation that the confined CSM is common, a striking diversity has been emerging, but the very small sample does not allow further investigation. Inspired by this proof-of-concept, we propose ToO observations of two CCSNe at Bands 3 and 6; one SN from a compact He or C+O star and another SN from a giant progenitor. This will allow us to study whether the final activity is dependent on the nature of the stars. This project will bring us new and robust information on the yet-unclarified final evolution of massive stars. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2023-10-25T20:27:31.000 |
| 4021 | 2013.1.00208.S | 21 | A systematic study of gas in z > 2 Main Sequence galaxies | We propose to measure total dust masses in 27 Main Sequence galaxies at 2 < z < 2.5 for which we are obtaining CO measurements and other diagnostics of the gas content, including star-formation rates, metallicities and gas outflows. Our goal is to use this combined 5-dimensional data to build up a self-consistent picture of the mass and atomic/molecular state of the gas and thereby better understand the cosmological regulation of star-formation in Main Sequence galaxies. We will also investigate and isolate possible systematic effects arising from the lower metallicities of these gas- rich systems. This comprehensive data set of high quality measurements on a representative sample of galaxies will also be important for calibrating other less extensive data or those obtained at lower signal to noise. | Galaxy structure & evolution | Galaxy evolution | 2016-01-23T17:55:13.000 |
| 4022 | 2021.2.00183.S | 22 | Measuring 12C/13C with CN and 13CN 2-1 for two source on the Galactic outer disk. | The 12C/13C, 16O/18O and 14N/15N abundance ratios indicate rich information about physical processes regulating the evolutions of stars and galaxies. The Galatic CNO isotope gradients are essential to constrain chemical evolution models of the Milky Way and indicate the stellar models in different regions of the Milky Way. The data of CNO isotope ratios lack on the metal-poor Galactic outer disk and the 16O/18O and 14N/15N values are calculated by 12C/13C values. However, the previous observations of several molecular clouds on the outer disk shows that the only 12C/13C point on the outer disk in literature is unconvincing. More observations for an update 12C/13C gradient are required for further 16O/18O and 14N/15N calculations and constrain the Galactic chemical evolution. We select two strong sources with low declinations in the IRAS catalog. We plan to use ACA to observe CN 2-1 and 13CN 2-1 to calculate 12C/13C to supplement the 12C/13C samples on the Galactic outer disk and give more constrain on the chemical evolution. The bonus lines such as CO 2-1 and CS 5-4 and the continuum emissions will also help us understand gas properties in this region with low metallicity. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-10-07T07:12:17.000 |
| 4023 | 2016.1.00938.T | 39 | Measuring Extended Source Species in a Bright Apparition TOO Comet | Certain molecules observed towards cometary atmospheres have a physical distribution that cannot be explained as direct sublimation from the nucleus or gas-phase chemistry within the coma. The extended source of these species is not known. As part of a joint collaborative multiwavelength effort, we will conduct an observational survey of extended source species and their possible parent or related molecules in a target of opportunity comet. This study will image HCN, HNC, CO, H2CO, and CH3OH to compare distributions within a given apparition and to previous ALMA observations. These observations will help constrain the origin and extent of the distributed source for each species, the scalelength of the source, establish accurate molecular abundances, and provide insight into comet chemistry. These results will build off data in the four comets previously observed with ALMA. The target of opportunity comet should have Q(H2O) ~ 1e29 s-1 and may be a new dynamical object or a known apparition undergoing an outburst event. We propose to observe with either the 12m array or the ACA depending on the current array configuration at the trigger. | Disks around high-mass stars | Disks and planet formation | 2018-05-07T08:23:31.000 |
| 4024 | 2016.1.00033.S | 20 | A bipolar outflow of CIT 6: introduced by an eccentric long-period binary? | Preplanetary nebulae (pPNe) are short-lived but important objects for understanding the transition between the asymptotic giant branch and PN evolutionary phases. Recent molecular-line mapping observations show that an increasing number of pPNe consist of outer near-spherical (shell/arc) patterns, and inner highly-asymmetric (bipolar/multipolar) structures. These features imply the simultaneous and puzzling presence of wide and close binary interaction - our favored hypothesis is the presence of eccentric binaries at the center of these pPNe. We propose an ALMA study of the carbon star CIT 6, that displays both a spiral-shell pattern and a nascent bipolar structure, to test our model. Our previous SMA observation have shown hints of an eccentric orbit binary through the possible presence of one-sided gaps and an inner double spiral. Our proposed high angular/spectral resolution and sensitivity study will enable us to characterize crucial observational signatures for our model, including (1) the double spiral, which was patchy and debatable in the SMA map, (2) kinematics of the bipolar structure, and (3) the physical conditions of the arm and interarm regions. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-05-17T00:00:00.000 |
| 4025 | 2012.1.00784.S | 9 | Tracing the 3D infall and rotation of material onto the massive protostar W33A | We propose to trace the 3D velocity field of material accreting onto a massive protostar for the first time. This builds on our tantalising discovery of the signature of both rotation and infall in our previous SMA observations of methyl cyanide lines. The velocity centroid map showed a 'twist' in the rotational pattern of the emission line that is nicely explained with an infalling component in our models. We will use the higher resolution of ALMA to follow this material down to within 1000 AU of the accreting object. Our multi-transition study of different K ladders will probe gas at temperatures from 60 to 600 K in bands 6 and 7. The degree of twist is predicted to change for transitions that arise from hotter gas closer to the star. Hence, we can map out the 3D velocity field and bring a valuable new test for theories of accretion in massive star formation. These data bring a different viewpoint to those using inverse P Cygni profiles that mostly probe the radial component of infall. Our target is the proto-typical massive young stellar object W33A. It is an ideal test bed as a luminous and very embedded object with a unique array of complementary high resolution data. These include mid-IR interferometry probing the warm dust at 40 milli-arcsecond resolution and AO-fed integral field near-IR spectroscopy revealing an ionized jet and evidence for an accretion disc via the CO bandhead line profile. The near-IR reflection nebulosity also constrains the shape of the outflow cavity and the inclination. Hence, our target has sufficent high resolution, multi-wavelength data to warrant sophisticated 3D radiative transfer modelling without the degeneracies due to large numbers of unconstrained parameters that often afflict interpretation of such datasets. We have already developed 2D axi-symmetric models of the dust and gas emission. These help us both predict what ALMA will see and are ready to interpret the data we would obtain. Modelling the wealth of high spatial resolution information on the dust continuum sets up the density and temperature structure with which to model the molecular emission. With the exquisite quality expected from the ALMA data we are likely to be able to move on from using simple collapsing and rotating analytic solutions to directly testing the latest numerical simulations that treat radiative and magnetic forces. The bright (~50 K), compact (<3 arcsec) line emission from W33A means that this target is well suited to a single configuration study in cycle 1. This project will be an excellent demonstration of the 1 km long baseline capability of ALMA and provide an early science highlight. | High-mass star formation | ISM and star formation | 2016-08-15T11:46:20.000 |
| 4026 | 2018.1.01720.S | 13 | Mapping CO emission in the unusual comet 29P/Schwassmann-Wachmann 1 | There is no other comet like 29P/Schwassmann-Wachmann 1. It has continually exhibited a dust coma since its discovery almost a century ago, and CO J=2-1 emission is readily observed with single dish telescopes. The CO line profile is split into two narrow velocity components, which provides clues to its origin. Mosaic maps with the IRAM 30-m showed a peculiar localized enhancement of CO emission in the coma, which was also near a dust enhancement seen in OIR images. Such features may be routinely present in this comet. At 6 au, the comet is too far from the Sun to sublimate water ice, but it is within the zone where models predict amorphous water ice patches can crystallize and release CO. We will deeply image the CO 2-1 emission in 29P's coma in order to 1) probe the physics and chemistry in this unique environment, 2) confirm and characterize localized CO emission in the inner coma, and 3) trace the two velocity components. These data will put significant constraints on models of nucleus composition and comae. The activity of distant comets also has important implications for other icy objects in the outer solar system, some of which may share common origins with comets. | Solar system - Comets | Solar system | 2020-03-01T00:14:02.000 |
| 4027 | 2015.1.01371.S | 38 | Rotating hot cores confining hyper-compact HII regions | Almost half of the mass of O-type stars is accreted after reaching the main sequence, when they are already producing vast amounts of UV photons. How high-mass stars keep accreting despite the onset of the ionizing radiation is not well established. A compelling possibility is that the inflow direction is perpendicular to the angular momentum of the rotating core, and that the first stage of development of an HII region, the hypercompact (HC), consist of an ionized biconical cavity confined by a rotating and contracting molecular core. We propose to use the ALMA to test a key prediction of this hypothesis, which is that all HC HII regions should be associated with a rotating hot molecular core. We target five luminous young high-mass stars associated with HC HII regions looking for velocity gradients consistent with a rotating core on scales 3000 AU using high-energy transitions of SO2 and CH3CN. We also observe the ionized gas emission traced by the H29 recombination line. The common presence of rotating cores around HC HII regions will help us to confirm the hypotheses of this simple model. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2017-09-12T10:03:33.000 |
| 4028 | 2024.1.00148.S | 0 | An Unbiased Molecular Gas Survey in the Lowest Metallicity Environment in the Magellanic System | Regions with metallicities less than 0.1 Zo correspond to a look-back time of more than 10 billion years. Studying the molecular cloud properties is crucial to understanding star formation in the distant Universe. However, such regions are almost depleted in the local Universe. The Magellanic Bridge, which connects the Large and Small Magellanic Clouds (LMC and SMC), has a metallicity even lower than the typical 0.2 Zo for the SMC and remains unexplored as a molecular medium, making it the last frontier for cloud factories in our Milky Way satellite system. However, molecular line emissions are extremely faint, making surveys challenging. Building on the results of recent ACA surveys of the SMC, we have designed an efficient observational setup to probe such faint regions: A Band 6 ACA survey in 12CO(2-1) covering an area of ~240 pc x 450 pc with a resolution of ~2 pc could identify up to a hundred small clumps. This extensive survey in the low metallicity regime provides fundamental cloud parameters such as the metallicity threshold for CO detection, the size-linewidth relation, and the mass fraction. It also serves as a guide for future high-resolution follow-up observations. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 4029 | 2017.1.00449.S | 34 | A disturbed transition disk: asymmetries and warps in RY Lup | One of the big results of ALMA Early Science was the discovery of dust traps: azimuthal concentrations of millimeter dust in transition disks with evidence for embedded planets, vortices and active planet formation. However, only two disks with azimuthal dust traps are known so far, both around Herbig stars. We have recently discovered another highly asymmetric disk around the T Tauri star RY Lup in Lupus snapshot surveys, but the spatial resolution of these data is insufficient to quantify its morphology. We propose to reobserve this disk in three wavelength bands (Bands 3, 6 and 7) at 0.15" resolution, which is sufficient to azimuthally resolve the dust trap. Furthermore, we include the 12CO 3-2 and 2-1 lines in our settings, to detect signatures of warp emission of a misaligned inner disk, which is inferred from radiative transfer analysis of the dust. Warps are not uncommon in transition disks, and may indicate the presence of a companion. RY Lup is a unique laboratory for testing dust evolution and planet-disk interaction models. | Disks around low-mass stars | Disks and planet formation | 2018-12-29T15:24:13.000 |
| 4030 | 2013.1.01193.S | 15 | Fragmentation in Hi-GAL clumps | The earliest stages of (high-mass) star formation are thought to be characterised by the breaking up of a molecular cloud into smaller objects, which then collapse into clumps (the precursors of star clusters) or cores (the precursors of single stars). We propose to probe for multiplicity a sample of cold and massive clumps extracted from the Herschel Infrared Galactic Plane survey Hi-GAL. The sample we propose represents the prototypes of protostellar clusters (or single objects), a phase in which fragmentation has produced the cores that will form stars. Establishing the frequency of fragmentation and the physical properties of cores in clumps will allow us to understand how massive stars form. This is the first time that an unbiased large sample of cold and massive objects can be selected on the basis of observations at wavelengths longward of 100 microns and represents therefore a golden opportunity to study the early stages of the formation of stellar clusters. We request 15 hours of observations with the most extended configuration of the ALMA array in band 6. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-11-02T21:52:37.000 |
| 4031 | 2016.1.00394.S | 25 | Unveiling chemical compositions of high-mass star-forming cores in low metallicity galaxies | Interstellar chemistry in low metallicity environments is crucial to understand chemical processes in the past universe. Prior to this proposal, we conducted spectral line surveys toward molecular clouds in nearby low metallicity galaxies, LMC and SMC, with single-dish telescopes. As a result, we found that molecular clouds in LMC experience chemical processes different from those in our Galaxy. However, the beam size of single-dish telescopes (5-10 pc at LMC) is too large to resolve internal structures of molecular clouds, and emission from star-forming cores (~0.1 pc), which reflect the chemical compositions of molecular gas associated with newly formed stars, is almost diluted out. Here we propose ALMA band 6 and 7 spectral line observations toward high-mass YSOs in LMC/SMC to unveil the impact of low metallicity environments on chemistry of star-forming cores. This proposal should elucidate a possible link between chemical properties of dense molecular gas and metallicity of the host galaxy. Furthermore, this program has potential to identify a hot molecular core in external galaxies, which should help understand chemical diversity of complex molecules in our universe. | Astrochemistry, Magellanic Clouds | ISM and star formation | 2018-03-06T11:57:40.000 |
| 4032 | 2018.1.01178.S | 7 | Closing the Loop of AGN Feedback: Cold Accretion in NGC 1275 within the Sphere of Gravitational Influence | ALMA recently has started to provide evidences of cold molecular gas which could have formed from warmer gas via radiative cooling in Bright Clueter Galaxy (BCG) systems. Such a cold gas is a candidate for the cold accretion which connects the feedback loop between the SMBH and host galaxy / ICM. NGC 1275, the nearby BCG in the Perseus cluster, is the ideal target to study the role of the cold accretion for the AGN activity. In Cycle 5, we detected the HCN(3-2) and HCO+(3-2) emissions within ~50 pc in NGC 1275, which showed a disk-like structure. This indicates that NGC 1275 possesses a significant amount of cold dense gas at its center, which is a possible connection with the cold accretion. Here we propose to observe the HCN(3-2)/HCO+(3-2) lines in NGC 1275 to study their properties within the Bondi radius, which will provide an unambiguous evidence that the cold gas is accreting to the SMBH. Thanks to its proximity, the observations with configuration-10 can resolve the Bondi radius of NGC 1275 (8.6 pc). The outcome will be a strong indication that the cold accretion is the dominant mechanism of mass fueling in BCG systems and eventually characterize the AGN activity. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-02-11T05:39:44.000 |
| 4033 | 2015.1.01210.S | 38 | Protolunar disks around directly imaged young exoplanets | The gas giant planets of the Solar System are surrounded by moons in large quantities, with at least 50 prograde moons thought to have formed in situ. Just like the Sun is not the only star surrounded by planets, it is very likely that extrasolar gas giant planets are also surrounded by lunar systems. Building on the properties of the solar system moon systems, we derive models for minimum-mass protolunar disks, which are essentially scaled-down versions of the minimum-mass solar nebula. Using 3D radiative transfer, we show that such late circumplanetary disks would be readily observable given the incident flux from the central host star, and might even be brighter if heated from the giant companion they are surrounding. We propose to test our predictions by observing three confirmed companions around nearby young (<30 Myr) stars (PZ Tel, And and AB Pic) with ALMA in Band 6 continuum and 12CO J=2-1. Given our simulations, protolunar disks around these companions should be detectable at >10 sigma in just a few minutes on source. | Debris disks, Exo-planets | Disks and planet formation | 2017-10-21T11:44:04.000 |
| 4034 | 2021.1.01054.S | 42 | Linking the Chemistry to the Morphology of the Ejecta of Supergiant VY Canis Majoris | High mass loss events are observed in evolved massive stars across the upper HR Diagram. The famous red supergiant VY CMa is the perfect star to explore these events. Previous optical spectroscopy and imaging of VY CMa revealed the 3-D morphology of its complex circumstellar ejecta and recent mass loss history. We propose to explore VY CMa's chemical enrichment history and association of molecular gas with these specific mass loss events. We will focus on the oldest, larger-scale structures (Arc1, Arc 2, NW Arc), but also examine clumps closer to the star (e.g. Clump C), combined with previous ALMA data and single-dish spectra from the ARO 1 mm survey. We will observe molecules that trace varying densities (CO, CS, HCN), evaluate 12C/13C ratios (13CO and H13CN), and further explore carbon and sulfur chemistry. These data will establish the physical and chemical properties of individual arcs and clumps across the entire envelope, providing insight into mass loss mechanisms. We also will examine aluminum and phosphorus chemistry, imaging PO, PN, AlO, and AlOH, in order to understand their spatial relationships and the influence of dust condensation and shocks on their formation. | Evolved stars - Shaping/physical structure, Evolved stars - Chemistry | Stars and stellar evolution | 2023-04-07T17:44:55.000 |
| 4035 | 2018.A.00037.S | 45 | Dust at Cosmic Dawn: Confirming the Highest Redshift Galaxy Candidate | We seek 7.8 hours of DDT time in bands 3+7 to spectroscopically confirm a Dusty Star Forming Galaxy (DSFG) as potentially at z~9. If at z~9, this would be the highest redshift spec-z galaxy and DSFG found to-date, 500Myr after the Big Bang, with an unprecedented 400 million solar masses of dust and SFR~700Msun/yr, which challenges our understanding of early Universe dust formation and massive galaxy formation. While it has been identified as a DSFG for years with unknown redshift, the delivery of 2mm ALMA data (5 hours after the Cycle 7 deadline) suggests a very high redshift solution (in conjunction with other millimeter constraints, including upper limits at lambda<850um). The optical/near-infrared data (very deep CANDELS HST imaging+SPLASH IRAC) is most consistent with a dusty galaxy at z~10. We have reprocessed ALMA Band 3 data and detect two lines at marginal significance (~4sigma) that coincide with CO(8-7) and CO(9-8) at z=9.3 (luminosities consistent with expectation). We propose to: (a) obtain higher S/N of the candidate lines in band 3, (b) rule out lower redshift solutions with one additional band 3 tuning, and (c) target the OIII emission line in band 7. | Lyman Break Galaxies (LBG), Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-11-15T02:27:35.000 |
| 4036 | 2023.1.00692.S | 0 | Tracing Astrochemistry through the Shadows | The current population of exoplanets revealed an incredible diversity indicating multiple formation pathways and subsequent evolution of planets. The chemical composition of the planet's atmospheres can provide an imprint of this formation history. Efforts to relate the chemical composition of planet-forming disks to the composition of planets are performed, with on one hand, the analysis of exoplanet atmospheric spectra, and on the other hand, deep molecular line observations of protoplanetary disks to derive the elemental abundances ratios. Though, most studies have focused on determining global ratios, only a few had enough spatial resolution to trace variations across disks in radius or even azimuth. We propose here to conduct a detailed astrochemical study at high angular and spectral resolution of the transition disk around RXJ1604.32130 A, that shows two shadowed cooler regions due to a misaligned inner disk. This will allow us to study the effects of azimuthal and radial brightness variations on the chemistry of planet-forming disks. In addition, we will assess the chemical signature of a recently detected planet candidate, responsible for the observed cavity. | Disks around low-mass stars | Disks and planet formation | 2025-05-14T00:59:44.000 |
| 4037 | 2013.1.00870.S | 9 | Tracing the accretion history of pre-main sequence stars through the envelope dynamics of FUors | A long-standing problem of the general paradigm of low-mass star formation is the "luminosity problem": protostars are less luminous than theoretically predicted. One possible solution is that the accretion process is episodic. FU Ori-type stars (FUors) are thought to be the visible examples for objects in the high accretion state. FUors are often surrounded by massive envelopes, which enable the disk to produce accretion outbursts and replenish the disk material. However, we have no information on the envelope dynamics, about where and how mass transfer from the envelope to the disk happens. We propose to use ALMA to observe the envelope of an FUor in different CO rotational lines to map its density and velocity structure. The observations will be analyzed using our modeling environment including a combination of hydrodynamical simulations and radiative transfer, which can model both the infall process and the disk accretion. It will enable us to measure the infall rate in the envelopes and calculate how often the object can produce repetitive outbursts. The results will help us to decide whether FUor-type eruptions can really be the solution to the luminosity problem. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 4038 | 2021.1.01083.S | 24 | A dust polarization survey of massive dense clumps in IRDCs | The role of magnetic fields in the formation of high mass stars is highly debated. Massive dense cores embedded in massive dense clumps are the fundermental element of massive star formation. There has been an increasing number of high-resolution and high-sensitivity dust polarization observations toward massive cores to reveal the role played by magnetic fields. However, inteferometric polarization observations of massive dense cores in infrared dark clouds (IRDCs), which is crucial for studying the initial condition of massive star formation, have only been made possible recently thanks to the sensitivity of ALMA. Here we propose for a dust polarization survey to map the polarized dust emission of a selected sample of massive clumps in IRDCs to study the magnetic field in early stages of massive star formation from the sub-clump scale down to sub-core scales. We will apply statistical methods to derive the magnetic field strength. With the estimated magnetic field strength, we will determine the dynamical state of the massive dense cores and distinguish between different massive star formation models. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-09-09T14:37:55.000 |
| 4039 | 2022.1.01251.S | 6 | 50pc imaging of a quasar host galaxy with young jets | Studies of quasar host galaxies are important for understanding the AGN-host coevolution. However, the local property of the quasar host galaxies has not been fully explored in the early universe. In order to circumvent the problem, we use gravitational lenses as natural telescopes. They enable us to resolve ISM around a massive AGN with a spatial resolution of <50 pc. This is more than four times finer resolution than previously reported result of quasar host galaxy at z =7. With this resolution (<50 pc), we will be able to directly image the host galaxy that interacts with the AGN jets. Using a de-lensing technique, the interaction between young jets and highly excited CO gas in a radio loud quasar has been detected recently. However, the property of the ambient ISM has not been probed yet. In this proposal, we aim to observe diffuse CO gas to determine the kinematic property of the ambient ISM in a quasar at z=2.639. Using a de-lensing technique, we will be able to resolve the low-energy CO gas on ~50 pc scales. Our observations will pave the way to understand the infant stage of AGN that may eventually evolve into a massive radio galaxy. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-05-24T10:57:09.000 |
| 4040 | 2022.1.00401.S | 275 | Mapping Molecular Irradiation Tracers in Extreme Bipolar Planetary Nebulae | Planetary nebulae (PNe) offer our last and arguably best look at the products of intermediate-mass stellar nucleosynthesis, just before that material is incorporated into the ISM. Though best known as photogenic optical emission line sources, a subset of PNe with pinched-waist, bipolar structures retain significant masses of cold, dense molecular gas and dust that is irradiated from within by UV and soft X-rays from exceedingly hot, rapidly evolving central stars. Such extremes of physical conditions within individual, readily resolvable objects with well-defined molecular gas irradiation geometries make PNe fertile ground for dramatically improving our understanding of photon-dominated regions and X-ray-dominated regions, such as are found in a diverse array of astrophysical environments. We propose ALMA molecular line mapping surveys of 7 objects that represent archetypes of the class of extreme bi-lobed/pinched-waist, molecule-rich, high-excitation PNe. The results will provide unique new insight into the the physical and chemical evolution of bipolar nebulae and, more generally, into the role of high-energy irradiation in driving molecular gas heating and composition. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR), HII regions | ISM and star formation | 2024-03-02T00:27:54.000 |
| 4041 | 2022.1.00893.S | 26 | Confirmation of size-dependent dust trapping outside of the planets | We propose Band 3 and Band 5 continuum observations of the transition disk around PDS 70 to confirm size-dependent dust trapping outside of the planets. This object has a wide dust ring outside of the planets, confirmed by direct imaging, so it is a perfect laboratory to confirm planet-disk interaction. It is expected that the dust grains are trapped outside of the planets, and the trapping efficiency depends on dust size. Larger dust is trapped and concentrated to the gas pressure maxima more efficiently, so the dust size is expected to be larger at the ring center than at the edges. We propose to estimate dust size across the ring with high-resolution multi-wavelength observations and confirm size-dependent dust trapping. We also estimate the dust mass at the dust ring and discuss the further formation of planets in the ring. | Disks around low-mass stars | Disks and planet formation | 2024-08-28T18:57:25.000 |
| 4042 | 2016.1.00620.S | 13 | The Core Mass Function and its Evolution in an Extreme Protocluster | The Core Mass Function is a theoretically important and observationally accessible component in the star formation process. It has not been characterized on the high mass (M>10 Msun) end due to sampling incompleteness despite the importance of high mass star formation for galactic evolution. We propose an observing program in the high-mass protocluster W49N -- the most luminous in the Galactic disk -- to observe a single-time snapshot of the CMF using 2400 AU resolution continuum observations. We will use gas temperature measurements with CH3CN and H2CO to more accurately determine the core masses and to measure the effects of stellar feedback on the CMF. We will constrain the evolution of this observed CMF by measuring the gas flows from parsec to core scales. This project will provide a powerful and detailed test of theoretical models of the CMF. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2020-07-04T00:00:00.000 |
| 4043 | 2021.1.00443.S | 80 | Surveying cold quasar outflows at the highest redshifts | Quasar-driven outflows are thought to be pivotal in shaping massive galaxy evolution at all redshifts. Winds of cold molecular gas in particular represent the ongoing removal of the direct fuel for star formation, allowing galaxies even at early cosmic epochs to quench following periods of rapid black hole accretion. Recent stacking experiments using CII detections of z~6 quasars have come to contradictory conclusions about whether outflows are present despite using many sources in common. We propose the first statistical survey for quasar-driven cold molecular outflows in z > 6 quasars, using the OH119um line as an independent and unambiguous tracer of outflows. Using an existing sample of z~5 non-quasars and large z~0 samples also observed in OH, we will directly compare the outflow occurrence rate, velocities, and mass/momentum loading factors between quasars and non-quasars in the first 1Gyr of cosmic history. Our survey will provide the first statistical constraints on molecular outflows in z>6 quasars and enable future studies of lower-luminosity, lower-M_BH systems to build a comprehensive understanding of quasar feedback at the highest redshifts. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2023-04-29T11:46:00.000 |
| 4044 | 2022.1.00159.S | 5 | Hidden Gems on a Ring: Resolving Embedded Young Massive Clusters in a Nearby Ringed Galaxy | We aim to understand the earliest phase of massive cluster formation with resolved observations of embedded young massive clusters (YMCs) around the starburst ring in the nearby galaxy M95. Leveraging lower-resolution data from a Cycle 8 program, we will observe extinction-free tracers of dust, dense molecular gas, and star formation in Band 3 and Band 7 at 0.05" = 2.5 pc scales. Complemented by a rich multiwavelength data inventory (VLA, VLT, HST, and JWST), our proposed ALMA observations will allow us to: (1) conclusively identify forming massive clusters at the earliest, heavily embedded stage, (2) characterize the impact of stellar feedback processes on YMCs, and (3) compare the physical properties of YMCs in different host systems. This will be just the fourth embedded YMC population study with resolved data down to ~2 pc scales and, more importantly, the first in a relatively face-on host system. With reliable measurements of YMC sizes, masses, gas fractions, feedback-related characteristics, and by connecting the YMCs to their ambient ISM and galactic environments, we will provide unique observational constraints for massive cluster formation theories and simulations. | Starbursts, star formation | Active galaxies | 2025-03-05T17:10:14.000 |
| 4045 | 2015.1.01080.S | 10 | Dust Cores around Sgr A* | The Galactic center region is the nucleus of the Milky Way galaxy. Sgr A* is a comapct source associated with the Galactic center black hole. Young and highly luminus clusters have been found by IR observations in the region. The Central cluster is centered at Sgr A* and has 100 OB and WR stars within r~0.5 pc. The formation mechanism of such cluster in the vicicnity of the black hole is an open question. We made a map at 350 GHz with high dynamic range (>2x10^4) and high angular resolution (0.44"x0.38")using ALMA archive data(2011.0.00887) and self-calibration technique. We found many dust cores around Sgr A*. The derived CMF is top-heavy and consistent with the IMF of the stars in the region. Most of the cores are partially resolved by the angular resolution. We propose 350-GHz continuum observation with higher angular resolution (0.1") to resolve the cores spatially. The fine structure of dust emission should be closely related with the dynamical state of the cores. This is a key information to understand the formation mechnism of the Central cluster. | Starbursts, star formation | Active galaxies | 2018-01-09T20:40:06.000 |
| 4046 | 2011.0.00374.S | 0 | Molecular Gas and Feedback in the Cores of Galaxy Clusters | We request short ALMA pointings toward the brightest cluster galaxies (BCGs) in the cooling clusters Abell 1664 and Abell 1835. Both harbour more than 10^{10} solar masses of molecular gas and nuclear starbursts that rank among the largest in the low redshift Universe. No known population of galaxies exists in clusters that could have donated molecular gas at these levels. The molecular gas, which probably formed from hot gas that cooled out of their X-ray atmospheres, may be fuelling the powerful AGN outbursts commonly observed as expanding radio bubbles, shocks and sound waves in the X-ray atmospheres of clusters. The short ALMA observations will immediately reveal relationships between molecular gas, cooling X-ray filaments of gas, star formation, and circumnuclear accretion disks fueling powerful AGN. The velocity profiles and molecular gas mass distributions will provide incisive clues to the origin of the molecular gas through measurements of its angular momentum and kinetic energy content. The proposed ALMA observations will map the mysterious cold phase of the radio-mode feedback cycle, which has emerged as the ``new physics'' in galaxy formation. | Outflows, jets, feedback, Galaxy Clusters | Active galaxies | 2013-06-04T13:41:00.000 |
| 4047 | 2022.1.01622.S | 6 | Probing the CO content of the low-ionization and small-scale structures in planetary nebulae | Planetary nebulae (PNe), being the fate of the evolution of the majority of the stars, are key for the chemical evolution of galaxies. This is so because from the asymptotic giant branch (AGB) and later phases, the rich chemistry of the progenitors is ejected to the interstellar medium. Our knowledge about these processes is based on PNe large-scale, high-ionized structures. It is well known that PNe also hosts pairs of low-ionization, small-scale structures (pLIS), whose origin seems to be closely connected with the launching and propagation of the jet-like outflows that shapes the transition from AGB to PNe. We aim to use the ALMA to reveal for the first time the spatio-kinematical distribution of the molecular material traced by the CO emission lines in a particularly interesting PN that exhibits pLIS (NGC 7009). Probing the molecular (and neutral) gas of pLIS will reconcile theoretical models for pLIS formation with the observations. The molecular H, atomic C and O are prominent in pLIS, and the first two were observed in the pLIS of this PN. The high sensitivity and angular resolution needed to detect the CO emissions lines of pLIS can only be achieved with ALMA. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2024-04-12T05:53:00.000 |
| 4048 | 2015.1.01349.S | 2 | Magnetic fields in different evolutionary stages of massive star formation | The role of magnetic fields during massive star formation remains unclear. Modeling indicates that the initial magnetic field conditions has significant effects on, in particular, the outflows. However, these initial magnetic field parameters are still poorly constrained. We have been able to reconstruct the three dimensional morphology of the magnetic field around a handful of evolved massive protostars using maser observations. Our eMERLIN 'feedback during massive star formation' legacy project is further increasing the number of sources with well defined field morphologies on the small scale. But how the field structure around massive protostars relates to the structure in the larger envelope and how the structure evolves in time is still an important open question. Only very few star formation complexes allow us to study the magnetic field at different evolutionary stages of the embedded cores at the same time. We propose ALMA observations of one of these sources G9.62+0.20 (part of our legacy project) for which a wealth of maser polarization observations indicates magnetic field differences between cores ranging from quiescent to having an embedded B0 star. | High-mass star formation | ISM and star formation | 2018-01-12T00:00:00.000 |
| 4049 | 2016.1.01481.S | 678 | Measuring the Spectral Evolution, Structure, and Speed of Extragalactic Jets with ALMA | We propose high-resolution imaging of 12 AGN with powerful kpc-scale jets in bands 3 and 6, in order to accurately map the synchrotron emission of the jet as it extends out from the host galaxy. Chandra X-ray observations have revealed very hard X-ray spectra which has lead to the prevailing interpretation that the X-rays are due to inverse-Compton upscattering of CMB photons (IC/CMB) by a jet which is still relativistic on kpc scales. However, very recent work by our group has shown that the gamma-ray flux implied by this mechanism is not detected, implying a mysterious second synchrotron component. ALMA provides the key measurement of the synchrotron spectrum of the jet near the sub-mm peak in order to exactly predict the gamma-ray spectrum expected & interpret the existing upper limits, and constrain theoretical alternatives. With the ALMA imaging we propose, we will be able to settle over a decade of ambiguity about the emission mechanism of the X-rays, and place strong limits on the their speeds on kpc scales. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-07-21T00:33:47.000 |
| 4050 | 2019.1.01427.S | 17 | Bright beacons? First survey of the [OI] 63-um emission in z>6 dusty starbursts | We propose a pilot study of the [OI] 63-um emission in a sample of z>6 dusty, star-forming galaxies. Predicted to outshine the [CII] line, the [OI]63 line is a potentially powerful tracer of molecular gas at the highest redshifts. With a total of 6 hours of ALMA Band 9 time, we will for the first time robustly detect the [OI]63 emission in three z~6 starburst galaxies, increasing the number of [OI]63 detections in z>1 SMGs by more than 50%. As ALMA Band 9/10 provide a unique window for studying the [OI]63 emission in high-redshift (dusty) starbursts, this study will open a new window for studying molecular ISM at the highest redshift,and provide key information for the planned FIR space observatories SPICA and the Origins space telescope. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2021-03-29T17:20:50.000 |
| 4051 | 2017.1.00608.S | 11 | Where does the Faraday rotation in M87 come from? | Members of our team have recently reported the first ALMA polarization measurement of Faraday rotation at submm wavelengths from the base of an AGN jet. We have found strong evidence of a very high magnetic field, possibly close to the Eddington magnetic limit. A similar scenario could be taking place at the jet base of the AGN in M87, where another group detected hints of high Faraday rotation from SMA observations at 1mm. These authors interpret the Faraday rotation in a different way, as due to a plasma screen related to inflowing material, and conclude that the accretion rate in M87 must be extremely low. We propose multi-frequency (bands 3 and 6) observations of M87, to definitely answer the question about the true origin of the Faraday rotation in M87 (either related to the jet or to the infalling material). This study is crucial for a better understanding of the accretion and jet-launching mechanisms in M87, which is one of the closest AGN to the Earth. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2019-11-30T14:57:19.000 |
| 4052 | 2016.1.00613.S | 420 | Rise of the Titans: Identifying Hyper-Luminous Starbursts back to the First Billion Years of Cosmic Time | Through a novel selection technique based on Herschel far-infrared colors, we have identified a well-characterized sample of dusty starburst galaxies at typically z>4, including the most distant example known at z=6.34. Based on our ALMA cycle-2 study, we have demonstrated that this technique is the most efficient one known for selecting dusty starbursts at z>5, but most sources are strongly gravitationally lensed. Critically informed by prior 0.15" resolution ALMA imaging, we here propose to expand this technique to systematically measure CO/[CI]-based redshifts, molecular gas masses, and star formation rate surface densities for the intrinsically most luminous unlensed massive dusty (hyper-)starbursts at z=4-7, which is expected to triple the number of such systems known. Such objects are thought to trace the most massive dark matter halos at these early epochs. Thus, a measurement of their space density and properties unhampered by any limitations of strongly-lensed samples will critically inform models of early structure formation, and significantly further our understanding of the star formation properties of the most distant massive starburst galaxies in the universe. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-01-25T14:11:00.000 |
| 4053 | 2015.1.01320.S | 15 | Dissecting starbursts at z=3.6 through multi-line H2O imaging | Submm multi-line H2O studies provide a unique probe of the densest starburst regions of ULIRGs where they measure the local IR radiation field. Strong gravitational lensing boosts ALMA sensitivity and angular resolution, enabling comprehensive studies of these sources with H2O lines at z~4. The impact of such multi-line H2O observations much benefits from combination with simultaneous highresolution imaging of the far-IR dust emission and CO lines, as shown in the SV observation of the prototypal source SDP81. Our IRAM/PdBI detection of H2O in 16 highz lensed galaxies has shown that strong H2O emission is ubiquitous in high-z ULIRGs. As in local ones, our modeling shows that it originates from highly obscured IRluminous regions. We have selected the best source with high-excitation H2O emission at z=3.63 for a new step of our ALMA highz H2O project. We will observe 5 H2O lines providing the full diagnostic power of H2O, in 3 tunings in standard ALMA modes. Mapping the FIR continuum and CO(6-5) at 0.25" will provide details of the source structure at 500pc resolution in the source plane, relating H2O emission and excitation to the overall structure and dynamics of the gas disk. | Starburst galaxies, Gravitational lenses | Active galaxies | 2017-12-08T18:46:42.000 |
| 4054 | 2022.1.01266.S | 22 | Putting kinematic planetary detection techniques to the test in HD 97048 | The velocity "kink" kinematic signature has gained standing as a promising method for discovering embedded planets. The gravitational influence of a planetary perturber is predicted to drive spiral wakes that disturb the surrounding gas velocity, generating distinct "kinks" along the spiral arms in observed velocity channel maps of gas emission. The understanding that velocity kinks are due to spiral arms enables us to make a robust prediction: Every instance of velocity kinks should be concurrent with spiral density waves in other tracers. We propose to search the Band 3 continuum for the spiral wake responsible for the observed velocity kink in the HD 97048 disk. The perturber, HD 97048 b, has already been listed in NASA's exoplanet archive as a confirmed ~2 Jupiter-mass planet. Our observing setup has been carefully designed such that we will be able to draw definitive conclusions as to whether a continuum spiral is present, in the case of a non-detection. Our program will provide an independent verification for the existence of the predicted planet, and more importantly, test the validity of velocity "kinks" as signposts of planets in disks. | Disks around low-mass stars | Disks and planet formation | 2024-07-13T12:39:09.000 |
| 4055 | 2023.1.00833.S | 0 | GMC scale CO(2-1) observations in the tidal dwarf galaxies in Antennae system | We propose 60 pc scale CO(2-1) observations of the Antennae's Tidal Dwarf Galaxies (TDGs). Recent extensive GMC survey on nearby star-forming galaxies calls for expanding GMC measurements to other galaxy types to reveal the role of large-scale structures such as spiral arm in promoting star formation (SF) in GMCs. TDGs, formed from tidal debris of interacting galaxies, provide unique environments to study GMC properties and SF activity, where large-scale structures are absent and tidal forces exclusively influence them. Despite a molecular gas surface density and H2/HI ratio in the TDGs are comparable to those in nearby star-forming galaxies, the SFE is significantly low, suggesting that the properties of the GMC are different. Thus, targeting TDGs in Antennae system, we aim to clarify the differences in GMC properties in typical TDGs compared to nearby galaxies and identify the causes of the extremely low SFE, leading to paradoxically demonstrating the importance of the large-scale structure in promoting SF in the GMC. We will test two scenarios caused by tidal forces (1) lack of GMCs themselves, and (2) a high ratio of gravitationally unbound GMCs. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2025-11-17T18:17:23.000 |
| 4056 | 2021.2.00066.S | 8 | How common are extreme molecular haloes around z~2 quasars? | Cicone et al. (2021) reported the discovery of a giant CO(3-2)-line emitting halo extending out to r~200 kpc from a quasar at z~2 selected to have known kpc scale outflow. Such halo was resolved out by ALMA and could only be revealed through fairly deep ACA observations. This molecular circumgalactic medium reservoir may embed a massive amount of molecular gas, and it does not appear to be associated with an overdensity of optical, infrared or sub-millimeter emitters around the quasar. We propose to expand the relevance of this discovery for the field of galaxy formation and evolution by extending the search for massive >100kpc-size CO haloes in additional five z~2 AGN, hosting a wide range of kpc scale outflow properties, using similar deep ACA CO(3-2) observations. The goals of this pilot study are: 1) a first assessment of how common these massive H2 haloes are at z~2; 2) understand the relevance of AGN outflows in the formation of this cold phase of the CGM. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2024-08-23T12:58:18.000 |
| 4057 | 2011.0.00275.S | 0 | Dissecting disks around B-type (proto)stars v1.10 | The goal of this proposal is to resolve the spatial and velocity structure of two carefully selected disk candidates around B-type (proto)stars and determine their properties. Through these observations we aim to test/confront the recent theoretical scenarios of massive star formation, that require non-axisymmetric disks with significant spatial and velocity sub-structure. In particular, we will look for non-axisymmetry, substructure, (non)Keplerian motions, and also determine physical parameters such as radii and masses of the disks. The chosen disk-candidates are associated with luminous sources, display mid-infrared dark lanes with disk morphology encompassed by wide-angle bipolar nebula. The feasibility of this experiment is justified by the presence of compact ammonia cores at the center of the mid-infrared dark lane, and the detection of broad SiO line wings and radio continuum emission coinciding with the bipolar nebulae. These targets will provide a step further in complexity and will triple the census of accretion disks round B-type (proto) stars, besides IRAS20126+4104, the unique case of Keplerian disk studied so far. | Disks around high-mass stars | Disks and planet formation | 2013-08-16T08:17:54.000 |
| 4058 | 2024.1.00377.S | 0 | Connecting the dots: study of the thermal and non-thermal processes in the extreme cluster "El Gordo" | Mergers represent episodic, but crucial events in the evolution of galaxy clusters. These energetic processes drive large-scale shocks and build turbulence within the intracluster medium (ICM), imprinting key perturbations to its thermal structure. At the same time, mergers impact non-thermal components (cosmic rays, magnetic fields) by means of (re)acceleration and amplification processes. Despite the great advances in the past years in the context of cluster studies, the connection between the thermal and non-thermal phenomena is still an unsolved puzzle. With the aim of deepening our understanding of the interlinked nature of the thermal and non-thermal ICM components, we here propose to perform a wide-field ACA+ALMA Band 1 mapping of the Sunyaev-Zeldovich (SZ) effect from the galaxy cluster ACT-CL J0102-4915, the famous "El Gordo". The combination of the proposed SZ observations with the latest X-ray and radio measurements will open a novel perspective on the multi-component ICM in this exceptional system. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 3000-01-01T00:00:00.000 |
| 4059 | 2022.1.00333.S | 10 | Is the star formation in one of the most massive cluster at z>1 fuelled by a cooling flow? | SPT-CL J2106-5844 (SPT2106; z=1.132) is among the most massive known galaxy clusters at z>1, and its BCG is accompanied by a ~70 kpc long star-forming filament identified in HST rest-frame UV images. Recent ALMA SZ, X-ray, and radio studies have revealed multiple mass and gas components, indicative of a recent cluster merger, and that the BCG is located within a cool X-ray core with strong radio jets along the same axis as the star-forming filament. The observed spatial correlation suggests a connection between the starburst event, thermally unstable gas, the AGN activity, as commonly observed in cool-core clusters at low z. As only one other high-z cluster has been found with similar properties, this would be a tremendous find, confirming that AGN feedback processes may be central in inducing thermal instabilities and fuel star formation >8Gyr ago. Alternatives include triggering from a wet merger with the BCG, or uplifted cold gas from the radio jets. To distinguish between these alternatives, we aim to exploit ALMA's unrivaled capabilities to probe the CO J=2-1 emission from SPT2106 and to constrain the amount and velocity structure of the molecular gas associated with the BCG. | Galaxy Clusters | Cosmology | 2024-02-06T17:50:25.000 |
| 4060 | 2017.1.01451.S | 36 | Resolved gas and dust in star-forming galaxies within the epoch of re-ionisation | Characterising the properties of the interstellar medium (ISM) of galaxies in the early Universe is one of the prime goals of observational astrophysics. Currently, ideal targets for such studies are luminous, spectroscopically confirmed galaxies at z~6-7. We have recently detected the most luminous [CII] line in such a z>6 source (CR7, Matthee+in prep). This high luminosity however is at odds with observations from other galaxies, indicating a large dispersion. For example, CR7 is at least 10 times more luminous in [CII] than Himiko, while their UV properties are similar. Moreover, three separate clumps in CR7 are resolved in [CII] emission, indicating metallicity variations of about a factor 2, confirming that clumps are in different evolutionary stages. We now propose to target two newly discovered, spectroscopically confirmed star-forming galaxies at z=6.55 (MASOSA and VR7). VR7 is even more UV-luminous than CR7, while MASOSA is UV-faint and potentially dusty. We propose to constrain their dust masses, their L[CII]/SFR ratio and gas-metallicity (from [CII] measurements), allowing us to constrain the enrichment of the ISM by the earliest generations of stars. | Lyman Alpha Emitters/Blobs (LAE/LAB), Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-03-27T13:20:17.000 |
| 4061 | 2015.1.00704.S | 117 | Unveiling a population of massive, dark ALMA galaxies at z=6 | While analyzing the data of a Cycle 2 project (PI: R. Leiton) in the COSMOS CANDELS field, we have discovered two "dark ALMA galaxies", unexpected 20 sigma detections in the 870um continuum that have no counterpart in any of the deep optical-to-NIR broadband images available in this field, except for the Spitzer IRAC channels. Photometric redshift codes place these sources at =5.7. Such estimates are of course highly uncertain and confirmation from spectroscopy is required. In fact, should these object be indeed at z=5.7, they would be among the most massive and dustiest objects known in the early Universe. Their extremely red UV colors indicate strong dust attenuation (Av>1), consistent with the relations found at lower redshifts, and at odds with recent claims based on z=6 Lyman Break selected galaxies (LBGs). The identification of these galaxies may prove to be a crucial benchmark to study the star formation and dust properties of high redshift galaxies. For this reason we propose to use the unique spectral scan capabilities of ALMA to target the [CII]158um line covering z=5.3 to 6.8 to secure the identification of these two galaxies. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2017-05-18T20:53:54.000 |
| 4062 | 2011.0.00115.S | 0 | Demonstrating Early ALMA Capabilities with the Extremely Luminous Giant Starburst `Himiko' Discovered at the Redshift Frontier | We propose Band 6 observations for a giant starburst, which we have dubbed 'Himiko', with a Keck spectroscopic redshift of z=6.595 discovered by our large area survey with Subaru in the UKIDSS/UDS field. This remarkable object free from strong AGN activity is unique in many respects including its high star-formation rate (100Mo/yr), large stellar mass (2x10^10Mo), and luminous gigantic Lya nebula which extends over 17 kpc; no equivalent source at this high redshift has been found, to date. As a well-studied object at optical and near-infrared wavelengths, it is an excellent target for early ALMA science. Our HST observations reveal a complex morphology indicative of a major merger whose large ionized nebula is produced either by an energetic superwind or cold gas accretion along the adjacent filamentary large scale structure. Given its intense luminosity we are likely witnessing Himiko during a key period of its mass assembly history. Our ALMA data will reveal the 1.2mm dust continuum and the kinematics of the [CII] 158um line thereby addressing the origin of Himiko's remarkable luminosity and the physical origin of the gigantic ionized nebula. In conjunction with the large set of ancillary data following our original discovery of this system, our proposed observations will provide a dramatic illustration of the capabilities of the early ALMA array by providing the first view of how the most massive galaxies formed close to redshift frontier z~7. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2014-02-22T06:04:00.000 |
| 4063 | 2022.1.01344.S | 250 | Zooming in on protostellar disks in high-mass star formation | There is growing consensus that the formation of high-mass stars (>8 Msun) proceeds through disk accretion, similar to that of lower mass stars. However, there is a critical need for a large sample that can homogeneously resolve and characterise the properties of these disks. We propose to observe 30 nearby (<4.5 kpc) high-mass protostellar disk candidates, uniformly selected from the ALMAGAL large program. We will observe the sample in both continuum and line emission at 1.3 mm using typical molecular disk tracers like CH3CN, HC3N, and salt lines, as well as more diffuse gas tracers like H2CO and CH3OH. With high angular resolution of 0.05'' (~150 au) we will resolve and characterize the physical properties of the candidate disks. Covering scales up to 0.6'' (few thousand au) we will trace the flow of gas in the transition region between envelopes and the inner disks. Our observations will be combined with the archival ALMAGAL observations that observed these sources with 0.3-30" resolutions, following gas flows from clump scales down to individual protostars to paint a comprehensive and/or diverse picture of the infall/accretion and outflow processes in high-mass star formation. | High-mass star formation | ISM and star formation | 2024-07-18T16:23:39.000 |
| 4064 | 2022.1.00474.S | 40 | A Systematic Search For Extragalactic AME in the Disk of NGC4631 | For over 20 years, the physical origin and prevalence of Anomalous Microwave Emission (AME) has remained an unsolved problem in astrophysics. Here we propose to use ALMA to observe the 90--230GHz continuum and CO J=2-1 line emission towards 11 star-forming regions in NGC4631, 5 of which are extragalactic AME candadidates, to: (1) Constrain the shape of the AME spectrum. Currently, no data at >44GHz and comparable resolution exists, leaving the exact shape of the AME and thermal dust emission completely unconstrained. (2) Measure a robust dust mass and emissivity from the Raleigh-Jeans side of the dust SED. We will test for correlations between the dust mass and AME morphologies that are naively expected if large accumulations of dust are required to produce strong AME. (3) Use the CO line emission to look for molecular gas to both measure the star formation efficiency and gas-to-dust ratio for these young (< 5 Myr) star-forming regions. We will additionally use the CO line width to investigate whether there is significant turbulence present that could be shattering larger grains, resulting in an accumulation of small grains powering the AME. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2024-02-28T22:25:31.000 |
| 4065 | 2016.A.00046.T | 46 | Continued ALMA Monitoring of the Nearest Short GRB | Short gamma-ray bursts (sGRBs) are presumed to result from compact object mergers (of two neutron stars, or one neutron star and one stellar mass black hole). For the past two weeks, we have been monitoring Fermi sGRB 170817A at X-ray through radio wavelengths and have obtained the most comprehensive dataset of any group to date. Here, we build on the success of our previous ALMA DDT to propose addtional monitoring of this unique object. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2018-05-17T16:19:29.000 |
| 4066 | 2021.1.00046.S | 250 | Exploring quick line and continuum variations in IRC+10216 | Millimeter line variation is a new direction of evolved star research. The stable array configuration of ALMA ACA makes it the best millimeter interferomter capable of long term high angular resolution monitoring of AGB stars. Based on ALMA archive data analysis of the archetypal carbon star IRC +10216, we have found possible non-sinusoidal variation patterns, secular trends, and short time oscillations of 1.1mm continuum and line fluxes. The short time variation could be the signature of shock activities in the AGB wind launching region. We propose to perform in Cycle 8 a combination of low (once per month) and high (once per week) cadence ACA-alone monitoring of the star in the same 1.1mm wavelength ranges as in the archival ACA data. We aim at determining the periodicity of these temporal behaviors and characterizing the short term variations. The data will provide unique constraints on complex excitation conditions in the AGB extended atmosphere and inform time dependent AGB wind models. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2023-07-26T12:34:15.000 |
| 4067 | 2019.1.00347.S | 33 | Isotope ratios as a probe of starburst ages and the stellar IMF? A critical observational test in the Antennae galaxies | It has been proposed that observed 18O/13C isotope ratios prove a top-heavy stellar Initial Mass Function (IMF) in starburst galaxies. This diagnostic has been used to argue for a top-heavy IMF in high-z starbursts. However, independent confirmation of this model in local galaxies is so far lacking. Here we propose a critical test of this diagnostic in the overlap region of the Antennae galaxies. This region contains a large number of well characterized young star clusters with a range in masses, ages and SFRs, and simple star formation histories. Isotope ratios derived from 1-0 lines of 12CO, 13CO and C18O will provide direct critical tests of the model. Both a confirmation and a rejection of the model will constitute an important result. At a resolution of 0.5"=50pc we will also study in unprecedented detail the molecular cloud population in the Antennae, including surface density, local free fall time and virial equilibrium in relation to the population of young clusters, and the star formation properties from MUSE data at the same resolution. In free subbands we will obtain high-quality images of the density-tracing CS(2-1) line, and of the continuum at 110 GHz. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2022-04-21T12:30:51.000 |
| 4068 | 2021.1.01100.S | 8 | Chemical Diagnostics of Star Formation in the Bar of NGC 2903 | How does the dynamics of molecular clouds under the gravitational potential of galaxy affect star formation? This is longstanding issues in the star formation study of nearby galaxy. A barred spiral galaxy is one of the best target to tackle the issues, because of characteristic gas motion in the bar. In the nearby barred galaxy NGC 2903, molecular clouds show weak star formation activities in the bar-end, which is connection point of the bar and spiral arm, although many barred spiral galaxies have active star formation in there. The difference would be attributed to gas dynamics, evolutionary stage of molecular cloud, or buried star formation in optically thick dust. In order to explore these possibilities, we propose multi-molecular line observation including shock, PDR, and dense gas tracers with ALMA in the 3 mm band at a scale of 65 pc. By using chemical compositions of molecular clouds as diagnostics tools, we will assess the environment of molecular cloud such as shock, PDR, and fraction of dense gas. This observation will provide us with an important clue to understand the effect of gas dynamics and shock on the star-formation in the barred galaxy. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2023-10-21T19:28:50.000 |
| 4069 | 2016.1.00598.S | 17 | Identification of a Proto-Brown-Dwarf System through Dynamics | The formation mechanism(s) of brown dwarfs (BDs, M<0.08 Msun) has been a longstanding problem. Resolving it requires studying their properties in the embedded phase (proto-BDs). We aim to identify a potential proto-BD, IRAS16253. Our SMA CO(2-1) map reveals two protostellar jets, suggesting it is a binary system. The low mass of parent core (<0.5 Msun) implies that the central objects may accrete only very limited material later. Thus, IRAS16253 is likely forming one or two BDs depending on the current masses and the future accretion. The CO jet shows periodic line-of-sight velocity variations along the jet axes which likely originate from the binary orbital motion. We fit the data with our model and deduce a binary separation of 69 au and orbital velocities of 0.52 and 0.10 km/s for the two components. This result implies masses of the central components of 0.026 and 0.006 Msun, which hints at IRAS 16253 being a proto-BD binary. We propose to observe C18O (2-1), CO (2-1), and dust continuum at 217 GHz to confirm the predicted binary separation and the velocities of the components. This will enable us, for the first time, to identify a proto-BD binary system through dynamics. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-09-09T03:36:15.000 |
| 4070 | 2012.1.00826.S | 12 | The mass infall rate of massive young stellar objects | Massive stars have a huge impact on their surroundings but their formation is poorly understood. High mass infall and accretion rates are predicted as a consequence of the high densities and non-spherical geometry required to form massive stars but this is poorly constrained observationally. A particularly important phase of massive star formation is the massive young stellar object (MYSO) phase, as it is during this phase that the majority of the final mass of the star is accreted. Understanding the mass infall rates in the envelopes of MYSOs as a function of radius is crutial to understanding how massive stars form, what the timescale and efficiency associated with this process is, and whether the disks around MYSOs are stable agains gravitational instabilities or fragmentation. Previous single-dish observations have primarily constrained the mass infall rates in high mass star formation regions on 1-0.2pc scales (10-25" at 4-8kpc), where it is not always clear whether the material is being accreted onto a massive star or simply the cluster potential. Interferometry observations have struggled with spatial filtering, sensitivity and primarily observed low critical-density transitions which probe the outer regions of the envelope around the young massive star. Band 7 observations with ALMA in Cycle 1 including the ACA will not suffer from these problems. We propose to observe a small sample of MYSOs from the well-defined Red MSX Source survey in the dense gas tracers HCO+ (J=4-3), CS (J=7-6), HCN (J=4-3) and H13CN (J=4-3) with ALMA. These observations will allow us to spatially resolve the envelopes of our sources on 0.6-10 arcsecond (2000-20000\,AU) scales and trace the velocity field in conjunction with radiative transfer models. The range of critical densities and upper energy levels of our chosen lines will allow us to constrain the mass infall rates as a function of position from the outer to inner parts of the envelope. This will provide us with a significant increase in our knowledge of how material falls onto MYSOs, and thus inform a new generation of more detailed theories and simulations. | High-mass star formation | ISM and star formation | 2016-10-09T14:36:16.000 |
| 4071 | 2018.1.01750.S | 26 | The structure of molecular gas in the vicinity of the closest known Gamma Ray Burst | Long duration Gamma Ray Bursts (GRBs) are luminous explosions with powerful energy releases detectable up to very high redshifts. To date the physical conditions for formation of the progenitors of these extremely bright events remains speculative. Super star clusters formed in massive Giant Molecular Clouds (GMCs) seem to be the likely birthplace for GRB progenitors. We propose to target the host galaxy of the closest known GRB for CO emission line observations with high spatial resolution to measure the molecular mass and surface density of the GMCs in the vicinity of the GRB, and investigate the formation of the GRB progenitor in star-burst mode of star formation caused by interaction which was revealed by our HI 21 cm emission observations. These observations allow us to also compare the properties of molecular gas in the GRB environment with the galaxy-averaged properties and detect features distinguishing the GRB environment. Even in the unlikely case of non-detection, we will be able to rule out the formation of the GRB in a super star cluster and in star-burst mode of star formation, and achieve the major part of our science goals by mapping the CO at lower resolutions. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2020-01-08T20:23:14.000 |
| 4072 | 2015.1.00810.S | 4 | The Eris-Dysnomia system: the key to understanding planet formation | The classical theory of slow pairwise accretion has been used for more than 40 years to explain the formation of planetesimals.Recent developments, however, have suggested that large bodies instead form directly from gravitational collapse after concentration in turbulent eddies or in streaming instabilities. Unfortunately,observational tests for distinguishing these possibilities have been ambiguous. Here we propose observations which could directly show that Eris, the most massive known dwarf planet, formed promptly through gravitational collapse. The key to this observation is measuring the density of Eris' satellite Dysnomia. Measuring the size of Dysnomia is now a straightforward ALMA observation. Measuring the mass is possible through a carefully designed program to make precise measurements of the reflex motion of Eris as Dysnomia orbits it. ALMA is uniquely capable of the providing the measurements required. With these quick observations we have the potential to answer one of the most fundamental modern questions about the early stages of planet formation, with applicability to planetary systems throughout the universe. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2017-02-17T22:22:26.000 |
| 4073 | 2013.1.00159.S | 24 | Biased SMG Formation at a z=3.1 Protocluster | Recently, we discovered a candidate for a extraordinary rich cluster of bright submillimeter galaxies (SMGs) at the core of the SSA22 protocluster at z=3.1. We find that 8 SMGs, which are likely to be at z=3.1, are concentrated within 12 Mpc region at the very center of the protocluster. Additionally 4 SMGs are also expected to be within the same protocluster. However the deficit of secure spectroscopic redshifts for 9 out of 12 SMGs prevent us from clarifying the relation between the SMGs and the protocluster (Our photometric redshifts have the typical uncertainty of delta-z=0.5). Here we propose to conduct spectroscopic observations with ALMA band 8 of the 12 SMGs to detect the [CII] 158 um emission line. We will utilize the spectral-scan mode and completely cover the redshift range of the protocluster (z = 3.06-3.12). Our aim is (1) to determine spectroscopic redshifts and unambiguously determine if the SMGs are associated with the protocluster. (2) to probe the nature of the SMGs using the [CII] line properties. The proposed study should clarify the environmental dependence on SMG formation. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 3000-01-01T00:00:00.000 |
| 4074 | 2016.1.00485.S | 13 | Dense molecular gas in a giant Lyman-alpha Blob | We propose to detect the dense molecular gas reservoirs of two submillimetre sources located within the original Lyman-alpha Blob (LAB) SSA22-LAB01 at z=3.1. The sources were identified in our Cycle 2 campaign, and represent the formation of what is likely to be a centrally dominant elliptical galaxy by z=0. By detecting the dense molecular gas (via CO(4-3)) in both galaxies we will address several key science questions: (1) what is the star formation efficiency (SFR/M_gas) of the two galaxies and can this be reconciled with cooling models predicting approximate equilibrium between the rates of gas accretion and consumption? (2) what are the precise redshifts of the sites of star formation in the heart of this LAB and how does this compare to surrounding galaxies and gas - in particular, how close are the sub millimetre sources in velocity space and in terms of the large scale Ly-alpha emission? (3) is there evidence of outflows potentially detectable by comparing the relative velocities of CO(4-3) and [OIII]? These questions will further our knowledge of the astrophysics of this system, in particular the interface between central galaxies and the surrounding circumgalactic medium. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2018-04-11T19:12:57.000 |
| 4075 | 2018.1.01630.S | 7 | Drilling Deeper: Resolved, cloud-scale dense gas measurements in NGC 300 | Within local Galactic molecular clouds, a Kennicutt-Schmidt relation between the star formation and mass surface densities does not exist. Instead, a dense gas scaling relation of star formation applies, which has previously been found to also hold for entire galaxies. This suggests that the dense gas scaling relation may be the more fundamental law of star formation. To test this scenario beyond the Milky Way, we have conducted a recently published large ALMA survey of 250 resolved Giant Molecular Clouds (GMCs) in NGC 300, the most nearby spiral galaxy that is accessible to ALMA, achieving a resolution of ~10pc in 12CO(2-1). Two attempts, in Cycles 2 and 4, to detect dense-gas-tracing HCN emission in some of these resolved GMCs have resulted in upper limits as low as HCN/CO<0.6%. Encouraged by an HCO+ detection and to definitively establish the utility primarily of HCN(1-0) and also of HCO+(1-0) as dense-gas tracers in extragalactic GMCs, we here propose to make use of our latest CO results to obtain a single deep follow-up pointing covering 13 GMCs, including our CO-brightest GMC, at a sensitivity that is 4x better than before, where non-detections would be unprecedented. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2021-06-26T17:07:28.000 |
| 4076 | 2015.1.01170.S | 0 | Mass accretion onto the Super Massive Black Hole of M 87 | Background: The rate of mass accretion onto Super Massive Black Holes is an essential parameter for active galactic nuclei. Goal of this Observation: With new polarization capabilities, we will derive the Faraday Rotation Measure (which is a tracer of column density) towards M 87 with 10 times better accuracy compared to our SMA pre-study. M 87 is a representative radio loud AGN. Scientific Impact: With 10 times more accurate RM, we will determine the mass accretion rate for the first time, while our SMA pre-study only allowed us to set an upper limit. It will enable us to discriminate accretion flow models and give us a unique opportunity to investigate the energy source of the jet (e.g., accretion and/or black hole spin). Why ALMA Cycle 3?: We need to investigate polarization properties in the vicinity of the beam center, but with high sensitivity (0.015 mJy/beam at Q and U) in band 3. Our sensitivity requirements can be only achieved with ALMA. In addition, we will use the RM measured from the more extended part of the jet to determine the foreground ISM contribution to the RM. That is useful information to confirm large RM is associated with accretion flow. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-03-25T01:38:01.000 |
| 4077 | 2013.1.00296.S | 5 | A search for extragalactic argonium, ArH+, a probe of the very atomic diffuse interstellar medium | The J = 1 - 0 transitions of 36ArH+ and 38ArH+ near 617.5 and 616.6 GHz were detected in absorption toward the Galactic Center source Sgr B2 with the Herschel Space Observatory. The former was also seen toward several prominent galactic continuum sources. Model calculations suggest that the cation samples in these observations exclusively the very atomic, diffuse ISM with a molecular fraction of about 10-4 or less. We propose to search for ArH+ toward PKS 1830-211 and B 0218+357 at z = 0.89 and 0.68, respectively, in order to gain more insight into the role of this cation as a probe of the very atomic, diffuse ISM and to determine 36Ar/38Ar ratios in the earlier Universe. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-08-01T10:16:49.000 |
| 4078 | 2024.1.01254.S | 0 | Supplemental observations of HD 169142 for a high fidelity Band 9 image | For understanding planet formation, it is necessary to constrain the dust disk properties such as the dust temperature, surface density, and size distribution. However, it has been challenging to constrain them only by observations because there is a significant degeneracy between dust temperature and surface density in low frequency ranges that are routinely observed with ALMA. To solve this degeneracy, we propose to use Band 9 that is more sensitive to the dust temperature. We target the prototypical protoplanetary disk around HD 169142 and aim to characterize the dust disk. Fortunately, high resolution Band 9 observations of this disk are already available, yet we found that their small maximum recoverable scale significantly affects the image fidelity. Therefore, we request supplemental short baseline observations. While the required observation time is just ~1 hour, the proposed observations enable us to not only obtain robust dust disk properties but also detect a potential circumplanetary disk around HD 169142 b. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 4079 | 2016.1.01205.S | 13 | Resolving substructure in the AA Tau transition disk | Transition disks are characterized by cavities, and based on recent ALMA observations of TW Hya, probably series of gaps throughout the disk. Such gaps are a key ingredient of planet formation theory, since they provide a barrier against the radial drift of grains and boulders. Observationally, however, we know that such gaps cannot completely stop the flow of gas and dust, as we continue to observe accretion of material onto the central star. The circumstellar disk will be rapidly depleted by accretion unless it is replenished, thus material must be crossing the inner cavity. Nascent planets can solve this dilemma by driving dynamical instabilities which funnel gas into gap-bridging filaments. These flows are likely common, but have only been directly observed in two disks. From Cycle 3 observations, we have serendipitously discovered that AA Tau hosts a multi-ringed transition disk with evidence for such a radial flow. We propose for higher spatial resolution observations to better study the dust substructure and gas dynamics, as AA Tau may offer rare access to this key dynamical process in planet forming disks. | Disks around low-mass stars | Disks and planet formation | 2018-11-03T04:31:45.000 |
| 4080 | 2019.1.00672.S | 34 | First 3D-Illustration of the Ionozed+Neutral Gas Down to 300-pc Scale Surrounding a Super Massive Black Hole at z=6.039 | We propose Band 6 and 8 observations for a luminous quasar (QSO) at z = 6.039, J2054-0005, with the high-resolution of 0."05 (or 300 pc) scale. Our cycle 5 observations reveal that J2054-0005 has the most luminous [OIII] 88-um line emission with the [OIII]/[CII] ratio ~5 times larger than other QSOs at z > 6. Moreover, the [OIII] region is distributed twice wider than the dust continuum and [CII] ones, indicating the existence of the AGN-driven outflow. With the uniquely [OIII] bright property, J2054-0005 is thus the best target to carry out the follow-up high-resolution observations, and we can test whether the AGN-driven outflow is indeed taking place in J2054-0005. We will perform the test via the following major goals: i) 3D illustration of the ionized and neutral gas distribution ii) evaluating the ionizing state via the [OIII] / [CII] iii) deriving the exact dust temperature via the continuum ratio at 88um and 158um. Note that we request two science goals for each Band, to obtain the best uv-sampling with the current cycle 0 and 5 data to recover the entire structure. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2022-09-28T06:41:34.000 |
| 4081 | 2018.1.01044.S | 439 | The systematic search for a causal connection between AGN-driven outflows and star formation | Leading models of galaxy formation require kpc-scale AGN-driven outflows to terminate star formation (SF). Observationally there is good evidence for outflows in many AGN but we lack clear evidence for a causal connection between outflows and SF. We recently completed our 25n VLT-KMOS program of distant AGN to undertake a systematic study of AGN-driven outflows and their impact on SF. We have constraints on the key outflow properties (outflow sizes, energetics, rates) but lack the sensitive SF measurements to test the outflow-SF connection. We propose for sensitive ALMA continuum observations of 63 AGN at z=1.1-2.4 (out of a sample of 103 with high-quality outflow constraints) that lack sensitive SF measurements. Our proposed observations will probe SF rates up to an order of magnitude below the mean for X-ray AGN at these redshifts, allowing us to identify even suppressed SF. With the proposed observations we will measure the distributions of SF as a function of outflow property (e.g., emission-line width; spatial extent; outflow energetics; AGN radio power) to systematically search for the "smoking gun" evidence for a causal connection between AGN-driven outflows and SF. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2020-01-23T17:43:31.000 |
| 4082 | 2023.1.00628.S | 0 | Looking through the dust trap: Band 3 and 4 observations of the HD 142527 disk | Many planet-forming disks have rich substructures in the dust, some of which are very asymmetric. The impact of such asymmetries (and substructures) on the chemical composition of the ice and the gas and, subsequently, of the potentially forming planets is dramatically illustrated by the IRS 48 ice trap. In this disk, molecular species have been found to be co-spatial with the asymmetric dust trap and this is thought to be the result of ice sublimation, following the radial and vertical transport of the icy dust grains, which also allowed for a unique view of the ice composition of disks. For the second most asymmetric disk, HD 142527, the role of the dust trap in setting the observable chemistry is much less clear. We propose to observe the HD 142527 disk in Band 3 and 4 to delve deep into the disk, to deduce the composition of both the gas and the ice, to figure out the extent of molecular freeze-out and to investigate the dominant chemical process(es). | Astrochemistry | ISM and star formation | 2025-01-22T17:39:51.000 |
| 4083 | 2015.1.00003.S | 31 | SPATIALLY RESOLVED CO SLED IMAGING IN NEARBY LIRGS | Recent single-dish and Herschel/SPIRE observations have successfully detected high-J CO emission (e.g., J = 4-3 up to 30-29) from nearby IR bright galaxies. The resultant CO excitation diagram is called the CO spectral line energy distribution (SLED). The gas excitation is usually modeled by a combination of an ISM model of cosmic-ray dominated regions, photon dominated regions (PDRs), X-ray dominated regions (XDRs), and mechanically dominated regions (MDRs) which are dominated by galactic-scale shocks. Analysis of single dish observations is successful in fitting the CO SLED with multiple components, which then provides the global contribution from each component; however, due to the coarse single-dish and SPIRE/FTS beam (~ 10 kpc), the CO SLED contains contribution from all of the molecular gas along the line-of-sight and one cannot convincingly determine the exact contribution from each component. The main goal of this proposal is to use spatially resolved CO observations of multiple J-transitions in order to investigate the powering source in three local U/LIRGs. | Merging and interacting galaxies, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2017-11-01T09:17:48.000 |
| 4084 | 2021.2.00050.S | 11 | A study of molecular clouds interacting with cosmic rays in the supernova remnant IC 443 | Supernova remnants (SNRs) are thought to accelerate cosmic rays (CRs), and yet its acceleration mechanism is not fully understood. In particular, the CR acceleration efficiency is still a matter of debate. IC 443 is one of the very few SNRs where the gamma-ray emission produced via collisions between CR and interstellar protons is identified, being an excellent laboratory to study CR acceleration in SNRs. Recently the near-infrared [FeII] and H2 observations find some evidence for presence of the 0.1-pc scale clumpy molecular clouds in IC 443. The clumpy clouds may allow CR protons to interact with large amounts of the interstellar protons in IC 443. However spatial resolutions of the current available CO maps of IC 443 are not high enough to resolve such clumpy clouds, preventing us from precisely estimating the interstellar proton density, an important parameter to evaluate the CR energy and thus the CR acceleration efficiency in SNRs. In order to evaluate the CR acceleration efficiency in IC443, with ALMA, we aim to investigate morphologies of the clouds in IC 443 at the 0.05-pc scale for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-11-09T20:02:58.000 |
| 4085 | 2022.1.00090.S | 0 | A comprehensive study of the most massive proto-cluster in the COSMOS field | The early stages of galaxy cluster formation remain poorly constrained observationally, particularly due to the low number of known cluster progenitors (a.k.a galaxy proto-clusters) at high redshifts. We have serendipitously identified an overdensity of six spectroscopically-confirmed galaxies in the middle of the COSMOS field at z=5.85, roughly 1 Gyr after the Big Bang. An analysis of the COSMOS2020 deep photometric redshift catalog reveals an overdensity potentially far more significant and large around the same redshift. Here we request [CII] observations (and dust continuum for free) on ~25 proto-cluster galaxy candidates to I) spectroscopically confirm the most massive proto-cluster in COSMOS; II) estimate its contribution to the cosmic star-formation; III) study the impact of environment on the star formation activity; and IV) test theoretical predictions on the early stages of galaxy cluster formation. This structure in particular is unique since it has a rich ancillary multi-wavelength data and guaranteed JWST NIRCam/MIRI and ALMA 2mm imaging, plus an excellent control sample representative of the field. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 2025-11-11T11:00:13.000 |
| 4086 | 2016.1.00138.S | 17 | Spiral Structures and Infall in the Circumbinary Disks around Protostellar Binaries | We propose to unveil spiral structures and infalling gas motion in the circumbinary disk of the protostellar binary system L1551 IRS 5, with the ALMA Band 7 observation of dust continuum emission and molecular lines at an angular resolution of ~0.14 arcsec. In the circumbinary disk of another binary protostellar system L1551 NE, we have identified two well-developed spiral arms and infalling gas motion from our ALMA Cycle 2 observation. On the other hand, our ALMA Cycle 1 observation of L1551 IRS 5 found a rotating circumbinary disk but no clear spiral arm feature and infall with the present Cycle 1 spatial resolution. In the present Cycle 4 proposal, we will observe L1551 IRS 5 at a similar angular resolution and a sensitivity as those of the Cycle 2 observation of L1551 NE. We will then unveil the difference of the spiral morphologies and infall between L1551 IRS 5 and NE with the different binary mass ratios, separation, and the disk centrifugal radii. This is the first critical step toward understanding of the growth of protostellar binary systems with the different physical properties. | Low-mass star formation | ISM and star formation | 2019-05-09T00:00:00.000 |
| 4087 | 2013.1.00186.S | 17 | Star formation in the 1000 km/s shock of Stephan's Quintet | The Stephan's Quintet group of galaxies is one of these must-do targets revealing surprises each time being looked at by a new instrument. The most striking feature is a giant intergalactic shock created by a 1000km/s galaxy collision, with very low star formation despite an amount of warm molecular hydrogen comparable to the molecular content of the Milky Way. Our Herschel [CII] and IRAM 30m CO(1-0) measurements show that the gas kinematics are complex (FWHM=1000 km/s) on large scales (10 kpc). PdBI CO(1-0) observations reveal molecular complexes of 2-5kpc in size, but with star formation efficiencies varying by a factor of 20. Why? We propose to map the CO(2-1) and SiO(2-1) emission at spatial resolution of 0.3", comparable to the size of Giant Molecular Clouds (GMCs), to measure the gas turbulence on scales where gravitationally bound clouds may form, and identify whether the star-forming regions in the shock are the sites of dissipation of kinetic energy through molecular shocks. These ALMA observations will characterize the role of the energy cascade, from bulk motions to turbulent motions on GMC scales, on the regulation of star formation in extremely turbulent environments. | Merging and interacting galaxies, Galaxy groups and clusters | Galaxy evolution | 2016-09-24T01:05:54.000 |
| 4088 | 2022.A.00032.S | 2 | A 5-pc-scale study of molecular clouds in the Antennae | In the current CDM framework, galaxies are thought to grow through mergers from gas-rich starburst galaxies to large quiescent galaxies. The obvious important step in characterizing the merging process is to observe nearby merging galaxies. The Antennae galaxies (NGC 4038/4039) are one of the nearest and the most famous merging galaxy pair. We propose to observe CO(10) emission from this galaxy pair with 0.05 arcsec resolution (5 pc) to see molecular cloud properties. | Merging and interacting galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2024-07-03T18:56:56.000 |
| 4089 | 2019.1.01027.S | 117 | Feeding the Beasts: Investigating the Merger-Induced Growth of Star-forming BCGs from 0.7 < z < 1.7 | We have discovered a new, and unexpected, formation mechanism for the most massive galaxies in the universe: Brightest Cluster Galaxies or BCGs. Although the standard theory indicates that BCGs assemble the bulk of their stellar mass through the accretion of gas-poor systems, our recent study has shown that at high redshift substantial in-situ star formation is occurring. We have posited that the driver of this star formation above z~1 is the merger of gas-rich galaxies with the BCGs, in contrast to rare cooling flow fed systems at z < 1. Here, we propose a continuation of a successful Cycle 6 program. In Cycle 6 we observed 13 star-bursting BCGs and here we request time for a comparison Main Sequence sample. We propose for 6 hours of Band-6 continuum imaging for a study of 13 systems within rich (i.e., massive) SpARCS clusters, spanning the redshift range of 0.7 | Galaxy structure & evolution | Galaxy evolution | 2021-01-31T15:06:31.000 |
| 4090 | 2015.1.00084.S | 32 | The Magnetic Field in 2 Known Class 0 Keplerian Disks | To date only 3 low-mass Class 0 objects have well detected >30 AU Keplerian circumstellar disks: L1527, VLA 1623, and HH 212. Other sources do not exhibit Keplerian disks down to 10 AU scales. What is the difference in these two populations? Although a small sample, there is an interesting trend. The sources with detected disks have inferred magnetic fields nearly perpendicular to their disk rotation axis, and the sources without disks have magnetic fields nearly aligned with their outflow axis (a proxy for the rotation axis). Many current theoretical simulations show that magnetic braking reduces the angular momentum of infalling falling, resulting in smaller circumstellar disks. In this proposal, we request time to measure the inferred magnetic field in the two brightest and closest Class 0 disk systems (L1527 and VLA 1623). With a resolution of 20 AU, we maximize morphology detection and increase sensitivity to the inner disk where outflow driving poloidal fields begin to dominate. With the ability to constrain the inferred morphology and magnetic field strength, we will make theoretical models to investigate magnetic braking and the early disk formation and evolution. | Disks around low-mass stars | Disks and planet formation | 2017-12-21T16:25:31.000 |
| 4091 | 2021.1.00353.S | 270 | Probing gas excitation variations in lensed starbursts at cosmic noon via sub-kpc imaging of [CI] and the CO ladder | Few detailed multi-J CO and carbon ([CI]) line radiative transfer analyses have been conducted for z>1 galaxies, despite growing numbers of detections. With wide-field/all-sky (sub)mm surveys, many strongly lensed, star-forming galaxies have been identified with apparent IR luminosities exceeding log(LIR) = 13-14 Lsun. These magnified star formation laboratories offer the most efficient means to study internal gas properties within the ISM of active galaxies at the cosmic peak in star formation activity. Here we request sub-kpc imaging of both [CI] lines, plus three CO lines strategically placed to sample the rise and fall of the well-modelled CO ladder. The global gas properties have already been constrained with multiple CO/[CI] detections, enabling i.) conclusive measurements of the sizes for the diffuse and dense gas emitting regions, allowing us to ii.) further apply a non-LTE radiative transfer modeling of the line/continuum simultaneously to resolve global trends. These lensed galaxies all have lens magnification factors of 7-20, intrinsic log(LIR) = 12.5-13.5 Lsun, and span 3 orders of magnitude in their gas excitation. | Starburst galaxies, Gravitational lenses | Active galaxies | 2023-03-28T21:24:09.000 |
| 4092 | 2015.1.00187.S | 55 | Gas in the most MASSIVE Galaxies | We propose to observe the molecular discs that lie in the heart of five of the most massive (M* > 10^11.5 Msun) early-type galaxies in the local universe with ALMA. Work by our team has shown that a non-negligible fraction of the most massive galaxies host molecular gas discs and star formation, but the origin of this material, its fate, and its effect on the host galaxy is poorly constrained. With ALMA observations we propose to shed light on this issue, while simultaneously using the relaxed kinematics of these discs to answer profound open questions in extragalactic astrophysics. For instance, the IMF of the most massive galaxies appears to vary, becoming more bottom heavy as the velocity dispersion of galaxies increases. We here propose a new, independent way to study this effect, deriving dynamical mass-to-light ratio profiles in massive ellipticals and thus constraining their IMF. The gravitational sphere of influence of the supermassive black holes in these objects are also resolvable, allowing us to constrain the demographics of massive black holes. | Early-type galaxies, Galactic centres/nuclei | Galaxy evolution | 2017-04-26T17:43:02.000 |
| 4093 | 2012.1.00941.S | 0 | Mass Loss from Massive Stars I | Massive stars have a crucial influence on the dynamics and energetics of the interstellar medium in galaxies due to their enormous luminosities and massive winds. This energy and processed material enrichment in turn influence further star formations in those galaxies. Therefore, a deeper knowledge about massive stars and their evolution is a prerequisite for improving our understanding of the Universe as a whole. The fast and dense stellar wind from massive OB type stars are driven by radiative line acceleration. It is thought that our understanding of massive star winds is well established. However, multiple evidence points to an over-estimation (by up to a factor of ten) of the currently accepted mass-loss rates from these stars as shown by inconsistencies in results derived using the linear and density-squared dependent diagnostics. The cause of the inconsistencies is attributed to wind clumping which strongly affects the density-squared dependent processes (recombination lines or free-free continua), but not so on linear-density-dependent processes(resonance-scattering lines or electron scattering profile wings). Models predicted that the clumping is radially stratified. Current observations study the base wind zones (H-alpha method), early intermediate zones (IR/FIR continua) and outermost zones (radio continua). However, a large region of the intermediate zone is currently unconstrained. The potential downward revision of mass-loss rates of massive stars will have a dramatic effect on the stars' evolution, on the corresponding feedback on their environments and hence on hte evolution of the host galaxy. Therefore we urgently need to establish the true mass-loss rates of OB stars, by constraining the clumping structure. If the radial stratification of clumping is known from consistent analyses by means of different diagnostic methods, realistic mass-loss rates can be derived. ALMA will provide the necessary sub-millimeter and millimeter observations to constrain the density/clumping structure in the intermediate wind zone, in which the wind is extremely sensitive to clumping. This knowledge is crucial to understand the inhomogeneities throughout the entire wind. In this proposal, we aim to obtain previously unknown mm/sub-mm fluxes from a carefully selected sample of OB-type stars for which we have information in other frequency ranges. The requested observations in the two or three ALMA bands will allow to accurately constrain the spectral indices of the SED which is controlled by the wind density and clumping structure. ALMA will provide the information which is mostly unknown thus far. The requested minimum SNR of 10 will allow us to detect the variation in the predicted flux levels by at least a factor of two in the ALMA bands, which in turn will show us the variation of clumping by factors of five to 10. With the crucial information provided by ALMA, we will be able to combine analysis of all diagnostics from the Far-UV to radio domain with consistency, in our elaborate Non-LTE wind models. This will lead us to the ultimate goal of derivation of clumping properties throughout the entire wind and help to constrain the physical origin of wind clumping. In summary, the proposed ALMA observation is essential for our understanding of wind flows and the magnitudes of mass-loss rates, and will provide an independent measurement of the amount of clumping in the wind. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-01-24T00:00:00.000 |
| 4094 | 2018.1.00470.S | 251 | Millimeter Monitoring of the Closest Planetary System - Stellar and Dust Emission from Proxima Centauri | At a distance of only 1.3 pc, Proxima Centuari hosts the closest extrasolar planetary system. However, Proxima Centauri has long been known as a flare star, making it a template case to explore the potential effects of variability on the planet's properties. We recently detected a flaring event in ALMA ACA observations during which the star brightened by a factor of 1000x over 1 minute. While this event throws doubt on previous claims of multiple dust belts in the system, it also opens a new observational window on the mechanisms responsible for stellar flares, since the flaring properties of M dwarfs have not been well-studied at these wavelengths. We propose Cycle 6 ACA monitoring of the Proxima Centauri system to 1) explore the nature of millimeter flares from M dwarf stars and (2) place deep limits on the presence and amount of dust in the system, if any exists. We will pair the millimeter observations from ALMA with simultaneous optical photometry from ground- and space-based observatories to determine the correlation between optical and millimeter flares, allowing for a thorough investigation of flare emission mechanisms at these wavelengths. | Debris disks, Exo-planets | Disks and planet formation | 2020-07-26T22:45:15.000 |
| 4095 | 2013.1.00457.S | 13 | A Molecular Disk Survey of Very Low-Mass TWA Members | There are precious few examples of young low-mass stars that harbor molecular gas within their circumstellar disks, yet are close enough to Earth for the sort of detailed observational studies that might constrain the conditions under which planets are born. It is essential to have a better understanding of the gaseous component of circumstellar disks as these govern how giant planets form. The ~10 Myr TW Hya Association (TWA) is an excellent group for such studies given that it is young enough to still retain some gas-rich disks (eg, TW Hya), old enough to have already formed planetary mass objects (eg, 2M1207b), and close enough (~60 pc) to permit detailed studies of its members. We propose an ALMA Band 6 survey for molecular gas disks around 15 very low-mass members of TWA, many of which will soon to be published. Our observations will be capable of detecting 12CO and 13CO line emission as well as continuum emission from cold dust in the circumstellar disks around these stars. This survey will be the definitive sample for molecular gas disks among ultracool dwarfs and will lead to a greater understanding of planet formation and evolution around low-mass stars and brown dwarfs. | Disks around low-mass stars | Disks and planet formation | 2016-03-23T17:26:49.000 |
| 4096 | 2018.1.01290.S | 10 | Is [CI] emission a reliable molecular gas tracer in galactic disks? | We propose a sensitive mapping of the [CI](1-0) line emission from the galactic disk of the nearby spiral galaxy NGC 3627. Combined with existing ALMA observations tracing the properties of its giant molecular clouds (GMCs) (from our PHANGS CO(2-1) survey), CO isotopologue maps (from EMPIRE survey), Herschel dust maps plus new optical MUSE IFU maps to characterize star-forming environments, we will address the following questions: (1) what is the [CI] conversion factor to molecular gas mass in a galactic disk environment? (2) do we see variations for the conversion factor with galactic environment? (3) how does it compare to the CO conversion factor? These questions are very timely to address as theoretical work has suggested that [CI] emission should be a highly reliable gas tracer in galaxies. However, observations of local (ultra-)luminous infrared galaxies and galaxy centers suggest that the situation might be more complicated. Though all these studies have focused on more extreme environments than those present in the disk (as proposed here). Given the easy access to this line for high redshift galaxies a thorough assessment of the [CI] as the gas tracer is urgently needed. | Spiral galaxies | Local Universe | 2021-01-18T02:55:22.000 |
| 4097 | 2012.1.00146.S | 0 | Newly found vibrationally excited H2O masers in Orion KL | We investigated the ALMA Science Verification (SV) data of Orion KL at band 6 and found a possible signature of the vibrationally excited H2O maser line at 232.686700 GHz (v=1, 5,5,0-6,4,3). This line has been detected in circumstellar envelope (CSEs) of late-type stars so far but not in young stellar objects (YSOs) including Orion KL. Thus, it could be the first detection in YSOs. With the ALMA SV data, we made a synthesized image of the 232 GHz H2O maser. It shows a remarkable peak at the position of the Source I, which is known to be a powering source of the SiO masers and 22GHz H2O masers. The spectrum shows a double-peak structure at the peak velocity of -5 and 11 km s-1. Interestingly, such a spectral profile appears to be consistent with the 43 GHz SiO masers and the 22 GHz masers. Therefore, it is most likely that the emission feature identified to be the 232 GHz vibrationally excited H2O maser would trace the similar physical structure as in the case of the SiO and/or the 22 GHz H2O masers. Nevertheless, the map of the H2O masers around the Source I are not spatially resolved due to the insufficient resolution of the SV data. Furthermore, we could not perfectly distinguish the contribution from the other HCOOCH3 line which lies close to the H2O maser line (232.68393 GHz) and contaminates in the H2O maser spectrum. Thus, it is still unclear whether the 232 GHz masers are distributed other than in the Source I, in particular in the Hot Core and the Compact Ridge where HCOOCH3 emissions are dominant. In order to establish the conclusive evidence of the maser emission from the vibrationally excited H2O line in Orion KL and to resolve its spatial distribution, we propose high resolution imaging of the 232 GHz H2O maser with ALMA cycle 1. For this purpose, the highest resolution of ALMA is crucial. Since the thermal emission of the HCOOCH3 line is expected to be extended and resolved out with the most extended configurations with ALMA, we will be able to separate the contribution from the H2O masers from that of HCOOCH3. With the present study, we will be able to reveal the spatial/velocity structure of the 232 GHz H2O maser features. It will provide information about the possible powering source of the 232 GHz masers whether they are associated with the root of outflows/jets as traced by the 22 GHz H2O masers or with circumstellar disk as traced by the 43 GHz SiO masers. Because both the SiO masers and vibrationally excited H2O masers are common for late-type stars but quite rare for YSOs, our results may imply similar characteristics of the Source I and late-type stars. Further studies with the millimeter/submillimeter masers with ALMA will be crucial to understand pumping mechanism and physical properties of these maser sources. The present study will be the first step for the future sciences with the millimeter/submillimeter masers with ALMA at higher spatial resolution. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2016-11-21T23:13:55.000 |
| 4098 | 2021.1.01058.S | 9 | Characterizing the Circumplanetary Disks in PDS 70 | The processes responsible for the formation of planets and their satellites are still to be unveiled. Observational data of forming planets, and even more of forming moons, are sorely needed. PDS 70 is a unique system to investigate planet and satellite formation processes as it hosts two directly imaged accreting planetary companions within the inner cavity of their host disk. Analysis of archival ALMA Band 7 observations indicates continuum emission at the location of the planets and represents the very first detection of a circumplanetary disk. However, the nature of the dust responsible for the emission is unclear, preventing us to understand whether dust grains can grow to form satellites and to probe the morphological connection between the planets and the inner disk. This motivates further observations in Band 9 continuum, at high angular resolution (~45~mas) to construct a spectral index map between 440 and 855 microns and unveil the nature of the emission near the two planets and in the inner disk. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2024-01-05T14:28:57.000 |
| 4099 | 2017.1.00659.S | 17 | The Precessing Molecular Jet in the NGC1377 Nucleus: Outburst from an Accreting SMBH | We propose high resolution (0."04= 4 pc) Band 7 ALMA observations of the center of the unusual S0 galaxy NGC1377. With ALMA we discovered a highly collimated molecular outflow in NGC1377 with velocity reversals that we attribute to a precessing molecular jet. The presence of the jet signals an unexplored and transient phase in the feeding of a supermassive black hole (SMBH). Our goal is to resolve the jet near the enshrouded nucleus and search for a hot circumnuclear torus. By mapping in the CO-3-2 and vibrationally excited HCN emission we will trace different physical conditions allowing us to probe separate components of the nucleus. We aim to (1) determine if the jet is powered by hot or cold accretion and if it is currently destroying its torus, and (2) investigate if the apparent precession is caused by a misaligned accretion flow or by a binary SMBH. This evolutionary phase should be extremely short-lived, which can explain other features of NGC1377, including its extraordinarily weak radio emission (far below the FIR-radio correlation). NGC1377 is nearby and offers a prime opportunity to study the interplay between SMBH growth and feedback in unprecedented detail. | Outflows, jets, feedback | Active galaxies | 2019-03-22T14:32:01.000 |
| 4100 | 2019.1.01763.S | 13 | Resolving the Kinematics of the High-velocity Gas in CO 0.02-0.02 | CO 0.02-0.02 is a peculiar molecular cloud found at 5' Galactic east of Sgr A*. Its spatial compactness (d<5pc) and extremely broad velocity width (dV>100 km/s) put the cloud in the category of high-velocity compact clouds (HVCCs). The association of an arc-shaped cavity which encloses a group of point-like IR sources may suggest that CO 0.02-0.02 has been accelerated by a series of supernova explosions in the embedded stellar cluster. However, we recently noticed that the highest-velocity gas in CO 0.02-0.02 significantly deviates from the cavity and its kinematics can not be reproduced by the single expanding-shell model. This means that plural different processes have contributed to its formation. Here we propose to observe the central region of CO 0.02-0.02 in the CO 3-2 line with ALMA. The primary objective of these observations is to examine kinematical models in the vicinity of the highest-velocity gas. We suppose the kinematics of multiple expanding shells, orbital motions around a compact mass, and outflows from protostars. Elucidating the origin of CO 0.02-0.02 contributes to the understanding of whole HVCCs and of the origin of turbulence in the central molecular zone. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-04-14T04:59:53.000 |
| 4101 | 2019.1.01175.S | 45 | CI survey | The gas observed in debris disks is thought to be produced from the collisional destruction of volatile-rich solid bodies. Combining observations of CO and its photodissociation product C can be used to determine the age of the disks. Surprisingly, this strategy revealed that the disks around beta Pic and HD 32297 are younger than a few 10'000 years, much less than the age of the host star (tens of Myr). This result is in sharp contrast to the current wisdom of debris disks being the result of steady-state collisional grinding of planetesimals. Instead, they might result from stochastic, short duration events such as tidal disruptions or giant collisions. To test this new idea, we propose to observe neutral carbon in seven debris disks in order to probe disks with different dust luminosities and CO contents. We will determine the carbon mass of each disk and study its spatial distribution in order to distinguish between the steady-state and the stochasitic event scenarios. | Debris disks | Disks and planet formation | 2021-03-17T17:21:47.000 |
| 4102 | 2024.1.00814.S | 0 | Hunting the prolongued dust growth in dusty quiescent galaxies at intermediate redshift | Recent findings of significant dust emission in quiescent galaxies (QGs) up to z~2 challenge the paradigm of a rapid removal of the interstellar medium (ISM) after the cessation of star formation. The origin of this excess remains enigmatic, as contributions from supernovae and evolved stars are likely negligible in QGs. Crucial for this understanding is the relative fraction of gas, dust, and metals in the cold gas-phase. Their direct and independent measure is however lacking, with current studies providing largely uncertain constraints. The cutting-edge cosmological simulation SIMBA hints at prolonged ISM dust growth as a leading mechanism for the wide range of dust fractions (>2 dex) in the ISM of massive QGs (M>3x10^10 Msolar) with super-solar metallicity. To test these predictions, we propose observing the largest, fully characterized sample of QGs at redshift 0.3 < z < 0.4 in the COSMOS field using ALMA band 6 to achieve S/N>5 in both the CO[3-2] transition and dust continuum. This sample will include 12 dusty QGs alongside 6 control IR-undetected QGs, directly constraining for the first time the scenario of dust growth and its evolution. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-10-15T05:36:40.000 |
| 4103 | 2013.1.00393.S | 1 | Mapping the Magnetic Field in the Circumstellar Disk in IRAS 16293-2422 B | Theoretical studies of magnetized cores show that the process of magnetic braking makes it very difficult to form a circumstellar disk in the earliest stages of the collapse. It is therefore important to detect, measure and map the magnetic field structure in the disk around a young stellar object. The SMA observations reported recently by us (Rao et al. 2013) of IRAS 16293-2422 B at 345 GHz are the first such measurements of the field structure in a disk. The field structure appears to be following a pattern which is approximately toroidal in geometry. However the SMA observations are affected by inadequate angular resolution (0.6 arcseconds) and sensitivity (relative position angle error of >7 degrees). We propose to image the magnetic field in the circumstellar disk around IRAS 16293-2422 B using ALMA in Band 6 with an angular resolution of 0.2 arcseconds | Disks around low-mass stars | Disks and planet formation | 2018-06-24T00:00:00.000 |
| 4104 | 2018.1.00001.CAL | 0 | Grid Survey | 3000-01-01T00:00:00.000 | |||
| 4105 | 2018.1.01545.S | 16 | Unlocking the TWA 3 Triple System with ALMA | Circumbinary disks around multiple stars serve as important laboratories in which to test dynamical theories of disk truncation and warping. They also serve as precursor analogs to the circumbinary exoplanets discovered by the Kepler mission. Thus far, all circumbinary disks around short period binaries (P < 40 days) have been shown to be coplanar with the stellar orbit. Kellogg et al. 2017 recently solved the spectroscopic orbit for TWA 3A, making it the closest and lowest-mass circumbinary disk around a binary with known orbital parameters. Intriguingly, there is evidence that the binary and disk are misaligned, possibly due to the influence of a hierarchical triple companion. We propose sensitive carbon monoxide observations, which will enable us to forward-model the velocity field of the disk and empirically measure the total mass of the central binary stars. Combined with Kellogg et al. 2017's spectroscopic solution, this will allow us to decisively measure the mutual inclination of the binary star and circumbinary disk, and determine how the stellar orbits (at both levels of the hierarchy) may be affecting the material in the circumbinary disk. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2019-12-06T17:53:55.000 |
| 4106 | 2021.1.00838.S | 38 | Stars or Black Holes? What mechanisms cause the rapid shutdown of star formation at the end of a burst? | Both AGN and stellar feedback have been invoked for driving galaxies from star-forming to quiescent. The evolution of the molecular gas immediately after a starburst has ended can constrain the physical mechanisms that have acted. Recent work has uncovered surprising trends in the gas state of recently quenched galaxies. Despite their low star formation rates, post-starburst galaxies retain large CO-traced molecular gas reservoirs. Furthermore, the CO-traced gas declines throughout the post-starburst phase, well after star formation has ended. Tentative evidence shows that the *dense* molecular gas may be depleted early in the post-starburst phase, suggesting stellar feedback may end starbursts by disrupting the dense gas clouds that would otherwise continue to form stars. We propose to measure the dense molecular gas fraction using the HCO+(1-0)/CO(1-0) fraction in a sample of five young post-starburst galaxies. These observations will test whether the galaxies have experienced rapid dense gas depletion from stellar feedback early in the post-starburst phase or whether the dense gas is depleted alongside the CO-traced gas throughout the post-starburst phase due to AGN feedback. | Starbursts, star formation, Early-type galaxies | Active galaxies | 2023-06-30T17:47:38.000 |
| 4107 | 2022.1.00145.S | 110 | Unlocking the legacy of Herschel: Snapshots of the Most Luminous Galaxies in the Universe | The full legacy of the Herschel surveys still remains locked away since, for the majority of the sources, current observations cannot distinguish between lensed and intrinsically-bright sources. Using efficient observations, we propose to obtain short (2-minute) band-7 continuum observations of 286 Herschel-selected high-z galaxies with robust spectroscopic redshifts, which provides for each source enough information to build a lensing model or identify the most star-bursting systems. Ongoing and completed redshift campaigns have painstakingly produced a near-complete catalogue of spectroscopic redshifts. These observations will allow the first statistical investigations of the extreme SMGs, including (i) investigations of their evolution through 'cosmic noon', (ii) probe any correlation between gas properties (from redshift surveys) with the galaxy's intrinsic morphology, and (iii) statistical investigations of rare objects, for example increasing the number of known starbursting HyLIRGS from <5 to 60. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2024-11-03T19:46:18.000 |
| 4108 | 2018.1.01465.V | 0 | Disorder vs. Order: Discerning the nature of the magnetic field in PKS 1510-089 | We propose using a combined ALMA+GMVA array to map the polarized emission emanating from the gamma-ray bright blazar PKS 1510-089 in an effort to discern whether the jet is magnetically disordered or ordered on the pc-scales probed by VLBI at 86 GHz. PKS 1510-089, along with a number of other blazars, has exhibited prominent orphan gamma-ray flaring behavior that can be explained by disordered turbulence in the jet spine or inverse-Compton scattering of photons emanating from regions of ordered magnetic field in the jet sheath. Determining the nature of the magnetic field within PKS 1510-089 using the high resolution (and sensitivity) afforded by a phased ALMA in concert with the GMVA will help discriminate between models of blazar emission that have been developed to explain this high-energy variability. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 4109 | 2015.1.00350.S | 10 | Imaging Gravitational Instability in the most massive FU Ori object | One of the surprising findings of ALMA's HL Tau observations is the lack of spiral arms and/or clumps, which are the ubiquitous features of gravitational instability (GI). Considering HL Tau is one of the most massive disks, it cast doubts on whether GI ever operates in protoplanetary disks. We propose to look for the signatures of GI in disks which are even more massive than HL Tau. FU Orionis/Exor objects are great candidates to search for GI as most theoretical models imply thay their disks should be unstable. Our ALMA Cycle-2 program has targeted several FU Orionis/EXor objects and we choose the most massive disk, V883 Ori (~0.6 Msun), to obtain high angular resolution data to search for the spiral arms and/or clumps caused by GI. Imaging GI would be a ground-breaking discovery. However, if we not find any signatures of GI in this extremely massive disk, it will put stringent constraints on all current disk outburst models. Whatever the case, our program will be a major contribution to the understanding of the FU Ori phenomenon. At 450 pc, V883 Ori is so bright (360 mJy in band-6) that it can be imaged at 0.034" (15 AU) resolution in only 1.2 hs. | Low-mass star formation | ISM and star formation | 2016-12-01T20:51:32.000 |
| 4110 | 2021.2.00150.S | 18 | MIGHTEE-CO: Adding molecular gas to the resolved neutral hydrogen across the past billion years | The balance of neutral and molecular hydrogen, how the components evolve with redshift, and their dependence on galaxy properties, are open questions. The intrinsic faintness of neutral hydrogen (HI) has until recently been the limiting factor in measuring the full gas content of galaxies at cosmological redshifts. With the SKA precursor facility MeerKAT, resolved observations of HI at z=0.08, corresponding to one billion years of lookback time, are now possible. We propose to use the ACA for a pilot programme, to observe the molecular gas via the CO(2-1) emission line in a representative sample of galaxies with resolved HI observations from MeerKAT at 0.04 | Spiral galaxies, Surveys of galaxies | Local Universe | 2023-06-07T16:36:59.000 |
| 4111 | 2015.1.00754.S | 50 | Zooming in on the AGN-driven star formation in distant, powerful, radio-loud AGN | High-redshift, radio-loud active galactic nuclei (AGN) provide a unique opportunity to probe the interplay between actively accreting black holes and their massive host galaxies. We performed a full infrared spectral energy distribution analysis of a complete sample of z>1 3CR sources, and found star formation (SF) rates of hundreds of solar masses per year in about half of the sample hosts. We discovered a clear trend where objects with subgalactic (<30 kpc) radio sources are much more common to show intense SF. This strongly suggests the occurrence of jet-induced SF (positive feedback) in massive galaxies during the peak epoch of AGN and SF activity. We request 0.15 arcsec resolution imaging of rest-frame 350 micron dust continuum emission in the hosts of five subgalactic 3CR radio galaxies and quasars, to zoom in on the SF activity on ~1 kpc physical scale, and test the positive feedback hypothesis. The resulting images will permit spatial separation of the nuclear (<1 kpc) and the extranuclear dust emission. Moreover, overlaid on deep, sub-arcsec resolution radio images, they will permit identification and quantification of positive feedback in these landmark objects. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-12-14T21:00:27.000 |
| 4112 | 2015.1.00183.S | 22 | The Pre-Stellar Core Mass Function with Deuterium Chemistry in an Infrared Dark Cloud | RESUBMISSION OF CYCLE 2 B-RATED PROPOSAL, WITHDRAW IF COMPLETED IN CYCLE 2. Similarities between the shapes of the core mass function (CMF) and the stellar initial mass function have been noted, which may reveal a fundamental aspect of the star formation process. However, the relation of these "cores", typically observed via their dust continuum emission, and the pre-stellar cores (PSC) that will actually form stars is unclear. Here we propose to measure the PSC mass function by mapping N2D+(3-2) over a contiguous region of an IRDC that we have already observed in N2H+ with CARMA and in which we have already identified at least two relatively massive N2D+ PSCs with ALMA in Cycle 0. We expect to identify ~75 N2D+ cores, and measure masses via mm continuum emission, mid-infrared extinction and virial methods. We will carry out astrochemical modeling of the cores to estimate deuteration ages, which can help de-bias the observed PSC mass function to obtain the true PSC mass function. We will also study the chemical evolution from PSCs to protostellar cores. Finally, we will measure core-to-core kinematics and compare with simulations of molecular cloud turbulence. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-10-23T06:33:59.000 |
| 4113 | 2019.1.00931.S | 8 | Bullet-proof: methanol as a smoking gun of a dusty jet | We propose to map at high angular resolution (0.26"; ~110 au) and high sensitivity (0.8 mJy/beam) the high-velocity molecular bullet emanating from the Class 0 protostar Ser-emb 8 (N) in CH3OH and H2CO. If CH3OH is detected in the internal shock within the bullet (in the internal working surface), this would be a direct and unambiguous evidence that the protostellar jet launched from this protostar is dusty. A non-detection from both CH3OH and H2CO will point to a dust-free jet and therefore constrain the launching radius of the jet below the dust sublimation point in the disk. Addressing the chemical content of the jet will thus be an unprecedented step toward a chemical inventory of the inner region of protoplanetary disks. | Outflows, jets and ionized winds | ISM and star formation | 2022-06-29T17:31:41.000 |
| 4114 | 2021.1.00178.S | 140 | How does environment impact the origin of stellar masses? A census of protostellar distributions in the CMZ | The assumption of a universal Initial Mass Function (IMF) underpins many key measurements in modern astrophysics. Surveying complete stellar populations to measure the IMF across environments in our Galaxy is complicated by variable extinction and shearing that destroys young clusters, particularly toward our most extreme local environment, the Galactic centre. The precursor to the IMF, the prestellar Core Mass Function (CMF), can be measured in both the Galactic disk and centre in the same way, allowing an apples-to-apples comparison. Such a comparison is necessary to test for CMF variation over statistically significant samples. We propose a large-scale survey of cores in the Galactic centre, designed to match the frequency, physical resolution, and continuum sensitivity of two accepted ALMA large programs studying the CMF in the Galactic disk. These data will enable a statistically significant, direct comparison of the CMF in the Galactic disk and the extreme Galactic centre. We aim to constrain what role environment plays in the construction of the CMF, and ultimately the origin of the IMF. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-10-21T15:44:02.000 |
| 4115 | 2013.1.00612.S | 2 | Imaging the Debris Disc Around the Planet Host Star HD 95086 | Only four systems exist with both detected debris discs and directly imaged planets: Fomalhaut, HR 8799, beta Pic and HD95086. Studies of the first three have led to groundbreaking new discoveries in our understanding of planet-disc interactions, but each system is unique. The last of these is the least well studied of the four since its planet was only discovered and the disc was only resolved in the past year. ALMA presents the perfect opportunity to obtain the first detailed image of this interesting system and find out whether and how the planet and the disc interact. We propose Band 6 observations to acquire detailed imaging of the disc in order to determine its structure and radial distribution. These can in turn reveal evidence of the influence of the planet on the disc. The resolved, high sensitivity data will allow us to detect modulations of the disk surface brightness as small as 20% and on a spatial scale as small as 40 AU (0.89"). Thus, the observations will not only allow us to constrain the disk properties, but also the architecture of the planetary system. | Debris disks | Disks and planet formation | 2016-11-19T02:27:58.000 |
| 4116 | 2021.1.00265.S | 320 | A Comprehensive [CII] Survey of Herschel-Selected Starbursts at z=3-6 | Based on a survey of the most luminous massive starburst galaxies found in >1000deg2 observed with Herschel, we have obtained a comprehensive sample of nearly 300 sources with secure, CO/CI-based spectroscopic redshifts. Here we propose to detect [CII] 158um emission from the star-forming ISM at z=3-6 in all 98 galaxies in our sample that are observable with the ACA, i.e., six times as many as in the largest massive starburst samples currently available. In combination with the rich suite of diagnostics already available, this study will provide critical insight into the physical properties of the ISM that set the conditions for star formation for a statistically significant sample, including a study of feedback based on the line profiles. Based on 9 systems in our sample for which we have already obtained <=1kpc resolution [CII] imaging with the ALMA 12m array, the ACA data will also provide a critical test for the potential presence of low surface brightness emission on >5-10kpc scales due to an enriched cold circum-galactic medium missed by high-resolution studies, as has been suggested to be present in star-forming galaxies in the early universe by some recent theoretical work. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2023-08-31T14:26:21.000 |
| 4117 | 2018.1.00427.S | 36 | Physics and Chemistry of Circumstellar Disks in their Earliest Stages | ALMA is uniquely suited to answer questions about how circumstellar disks form around low-mass protostars and how their physics and chemistry evolve until the planet-forming stages. We here propose to utilise the high angular resolution of ALMA to study a candidate for one of the youngest, most deeply embedded circumstellar disks toward the Class 0 protostar NGC1333-IRAS2A. With 10 AU resolution we will: (i) constrain the physics and chemistry of the inner envelope, and putative circumstellar disk, (ii) image the distribution and kinematics of water in the innermost regions around the protostar, and (iii) search for unambiguous evidence for an accretion shock in SiO. Together these observations will allow us to address what the physical and chemical structure is of deeply embedded protostars at the onset and scales of disk formation. If the data show the presence of a circumstellar disk on these scales, the presence or absence of water on the same scales will reveal whether such disks are formed "wet" or "dry". The presence or absence of an accretion shock will help answering the question of whether chemistry is preserved from the protostellar envelope to the circumstellar disk. | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-11-26T21:06:23.000 |
| 4118 | 2018.A.00056.S | 252 | Core mass function and formation mechanism of very low-mass stars | In order to understand the formation mechanism of very low-mass stars and the origin of the stellar initial mass function (IMF), we aim at deriving core mass function (CMF) fully sampled from the most nearby (130 pc) cluster forming cloud of Corona Australis employing the large-field mosaic observation with the ACA standalone mode in band 6. The survey is to be conducted in the dust continuum emission together with the dense gas tracer of N2D+ (3-2) line. The outcome CMF will be compared with the stellar IMF obtained by our deep near-IR observation that revealed large number of brown dwarfs and planetary-mass objects. In case that the resultant CMF resembles the IMF below 0.1 Mo, it supports the formation mechanism of collapsing low-mass dense cores, as a scale-down version of the formation of sun-like stars. The target CrA cloud has been surveyed be Herschel and the dust CMF is already obtained. The dust core detection below 0.1 Mo is still incomplete even with the Herschel's high sensitivity. The proposed ACA observations will reinforce the robust core detection with higher spatial resolution, the high critical density, and velocity information of the line. | Low-mass star formation | ISM and star formation | 2020-12-06T00:00:00.000 |
| 4119 | 2017.1.00391.S | 35 | WISDOM: Extending black hole demographics across the mass-size plane with ALMA | Ubiquitously present at the centres of galaxies, black holes are central to understanding galaxy evolution. However, the current sample of galaxies with measured black-hole masses is incredibly biased, tracing only specific regions of the galaxy mass-size and mass-velocity dispersion planes. As many galaxy properties vary across these planes, this bias could be fundamentally affecting our understanding of black hole scaling relations, and thus the relationship between galaxies and their super massive black holes (SMBHs). As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM), we have pioneered the use of molecular gas to estimate SMBH masses, and conducted the preparatory work required to select a large sample of suitable ALMA targets. Here we propose to map CO(2-1) at high spatial resolution a sample of objects spanning the unexplored areas of the mass-size plane to accurately measure their SMBH masses. In this way we can address selection biases, extend SMBH demographics, and shed light for the first time on potential variations of the SMBH-galaxy correlations using a unique technique (with the same systematics) across the galaxy mass-size plane. | Galactic centres/nuclei | Active galaxies | 2019-10-04T02:15:41.000 |
| 4120 | 2019.1.01695.S | 12 | Exploring Dust Evolution and Sub-structure Formation in an Infant Disk around a Class 0 Protostar | Now it is well known that various substructures are formed in PPDs. However, their origin is still controversial. For instance, it is still unclear whether ring structures really mean planet formation. It is thus important to examine when and where dust coagulation and settlement starts during the disk evolution. In general, disks are not in hydrostatic-equilibrium (HE) in their early stages. Nevertheless, the infant disk in L1527 has a doubly flared structure, which can be regarded as a sign of the transition to HE. In this disk, dust growth and substructure formation has already started. Furthermore, the low alpha index (~1.6) and the asymmetry only seen in the central part (r<10 au) may suggest self-scattering, substructure formation, or existence of dark lane. To understand their origin and the change in the alpha index at the boundary of the inner and outer disks (r~50 au), we propose multi-band continuum observations. By combining the available Band 3 and 7 data with the Band 4 and 6 data, we will address the above questions. The origin of the asymmetry and the low alpha index will be explored by the Band 7 observation at a 3 au resolution. | Disks around low-mass stars | Disks and planet formation | 2022-10-25T20:00:14.000 |
| 4121 | 2015.A.00013.S | 13 | A radioactive molecule in a stellar-merger remnant | In recent observations of the historic eruptive variable, CK Vul, we detected two emission lines of 26AlF, i.e. aluminum fluoride with the radioactive isotope of 26Al. This is the first direct detection of a radioactive molecule in astronomy. We propose to obtain complementary observations of a third line with ALMA. This observation will confirm our identification and make our excitation analysis of 26AlF emission more reliable. The detection of 26AlF will greatly improve our understanding of the peculiar chemical composition of the circumstellar material of CK Vul, which is most likely a product of a stellar merger from 340 yr ago. It will also shed light on the origin of gamma-ray emission attributed to 26Al decays and observed towards the Galactic plane. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2017-02-09T15:18:31.000 |
| 4122 | 2021.1.01257.S | 171 | Toward a Spatially-resolved Molecular Kennicutt-Schmidt Law in High-z Cluster Galaxies with ALMA | Our understanding of how gas is converted into stars on small spatial scales within z > 0.1 main-sequence galaxies has been hindered by a dearth of high-resolution imaging of the molecular gas component. However, a new window into spatially-resolved molecular gas has recently opened through ALMA observations of high-redshift galaxy clusters. These gains have been largely due to the high source density of star forming galaxies in young clusters, which allows for efficient multiplexing. The ALMA observations have yielded exquisite velocity maps and morphological analyses for the first large sample of spatially-resolved molecular gas in high-redshift galaxies. By combining these novel CO data with dust continuum imaging from band 7 ALMA, we will investigate the interplay between gas and star formation on kiloparsec scales, for 27 main-sequence cluster galaxies at z~1.6. This will be the first determination of the spatially-resolved Kennicutt-Schmidt law for a large sample of galaxies at high redshift, and will be a pioneering study of how gas is consumed by star formation on sub-galactic scales near the peak of cosmic star formation. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2023-09-12T10:54:11.000 |
| 4123 | 2017.1.00057.S | 245 | ALMA survey of extremely deeply buried AGN in ultraluminous infrared galaxies | We propose ALMA HCN/HCO+ J=3-2 line survey of nearby ultraluminous infrared galaxies (ULIRGs) which do not show obvious optical AGN signatures. These molecular emission lines can be used to scrutinize dust obscured energy sources at ULIRG's nuclei, thanks to different physical/chemical effects from AGN and starburst to the nuclear molecular gas and very small dust extinction at (sub)millimeter. Based on elevated HCN-to-HCO+ J=3-2 emission line flux ratios and/or vibrationally excited emission lines, we aim to detect the signatures of deeply buried AGNs which are believed to play an important role in ULIRGs but can be missed in previous studies. Our specific scientific goals are to (1) detect (sub)millimeter signatures of optically elusive buried AGNs in ULIRGs which have shown some infrared and/or hard X-ray AGN signatures, and (2) even evaluate the ubiquity of extremely deeply buried AGNs which are totally elusive in other wavelengths (optical/infrared/hard X-rays), but first detectable in our (sub)millimeter observations, due to even lower dust extinction effects. ALMA's high sensitivity and stable spectral baseline are indispensable for our systematic ULIRG observations. | Galactic centres/nuclei, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2018-12-26T00:57:21.000 |
| 4124 | 2022.1.00676.S | 0 | Magnifying the Galactic-scale Magnetic Field Structure in the High Redshift Universe | How the magnetic fields of galaxies have been generated and evolved in cosmic history is a major question in modern astronomy. Answering this question is hampered because we have no observation which shows spatially resolved magnetic structure on the galaxy disk at z>0.5. Recent studies show that the polarized far-infrared emission from magnetically aligned dust is a robust tracer for magnetic field structure. We propose Band 7 polarimetric observation towards strongly lensed dusty starburst galaxy SPT0418-47 at z=4.22 with a resolution of 0.3" (or 90-200pc after the lens reconstruction) to map out the magnetic field structure just 1.5 Gyr after the big bang. The strong lens of SPT 0418-47 and ALMA's unique capability allow us to detect the polarized emission. SPT0418-47, with a clear rotating signature of the gas, is an ideal laboratory to (1) test the dynamo mechanism in which a rotating disk converts the turbulent magnetic field to a regular magnetic field and (2) reveal how the magnetic field is important for the physics of interstellar medium at the early Universe. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2025-10-29T06:18:25.000 |
| 4125 | 2017.1.00257.S | 367 | Fueling and quenching star formation in and around z~0.5 galaxy clusters | This project aims at providing a self-consistent picture of how galaxy evolution is impacted by the environment, with particular emphasis on how star formation is quenched. We propose to target the CO(3-2) line in the ALMA Band 6 in and around two medium mass galaxy clusters at z~0.5, CL1411.1-1148 and CL1301.7-1139, which will deliver unprecedented molecular gas information for 53 star forming galaxies located in low density regions, filaments, groups, and clusters all belonging to the same large scale networks. We will address the following fundamental open questions: - Does the global molecular content of cluster galaxies increase with lookback time as it does for field galaxies? Are the factors of increase comparable? - How strong is the depletion in cold gas from the cluster outskirts to their inner regions? To which extent do the surrounding overdensities play a pre-processing role? | Galaxy groups and clusters | Cosmology | 2019-07-31T14:26:12.000 |
| 4126 | 2016.1.00284.S | 6 | The role of OH outflows in the high redshift Universe | Why were ultraluminous infrared galaxies (ULIRGs) at z>1 such a major contributor to the star formation density at that epoch, yet they contribute less than a percent today? A likely driver may be changes in Active Galactic Nuclei (AGN) feedback. Herschel observations of hydroxyl (OH) have proven extremely efficient in characterising AGN-driven outflows in the local Universe, and showing that they are relatively common. These outflows provide the only direct evidence that fuel for star formation is being removed. What are the properties of these outflows in the early universe? Are they powered by the same mechanism? We propose a novel study of AGN-driven outflows in 3 ULIRGs at redshifts 2.6-4.2, with the best available outflow diagnostic, OH, and the best available sample of gravitationally lensed sub-mm galaxies with good lens models, using the flux amplification to maximise ALMAs sensitivity to this key diagnostic. Our program will be the first detailed study of OH properties in ULIRGs in the high-redshift Universe. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-04-04T18:03:47.000 |
| 4127 | 2021.1.00490.S | 115 | Filament and high-mass star formation triggered by tidally-driven colliding HI flows in the LMC | Recent mm-submm facilities confirmed that filamentary structures are widespread across the Galactic molecular clouds and massive filaments are supposed to be precursors of high-mass stars. Although large-scale colliding flow may be a promising event to form such filaments, the idea is not well constrained observationally. The Large Magellanic Cloud (LMC) is a suitable target to investigate the effect of galactic-scale kinematics thanks to its nearly face-on view. ALMA observations toward a few particular objects in the LMC found that there are massive filamentary clouds within a possible compressed layer, which is originated from HI colliding flows induced by the last tidal interaction between the Magellanic Clouds. Most recent HI analysis shows the same compressed velocity components are almost ubiquitous in the other active star-forming regions in the LMC. In this new program, we will carry out survey-type observations toward these regions to search for massive filamentary clouds and investigate the environmental dependence of their properties. This is the first comprehensive exploration to study the relation between the low-density HI flows and high-density CO filaments. | High-mass star formation | ISM and star formation | 2023-01-05T04:29:07.000 |
| 4128 | 2016.1.00196.S | 30 | To launch or not: A study of magnetic fields in post-AGB objects with and without massive outflows | The study of magnetic fields in evolved stars is crucial for understanding the extreme departures from spherical symmetry that occur in the late stages of stellar evolution. Indeed the field's ability to launch and collimate the bipolar jets believed to be involved in the shaping of the envelopes of post-AGB (pAGB) objects is a matter of intense debate. But the observational study of magnetic fields so far is very limited. We therefore propose to use ALMA and its new full continuum polarization capability to study magnetic fields through observations of linear polarization of dust grain emission, in two well-studied pAGB objects. These are OH231.8+4.2 and the Red Rectangle, with the former showing a massive outflow and the latter a very weak one. The high-resolution ALMA data will allow us to detect and map the field at small scales and test the outflow-launching mechanism in each object. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-02-23T17:44:11.000 |
| 4129 | 2022.1.01691.S | 41 | Uncovering the physics that control cloud and star formation in gas-rich centers (CMZs) | Gas-rich galaxy centers like our own Central Molecular Zone (CMZ) are extreme environments for cloud and star formation where many formation promoting or inhibiting forces acting locally or on larger scales compete. We propose ~20pc resolution, sensitive (rms~0.5K per 2.5 km/s) CO(2-1) imaging of a representative, unbiased set of 20 nearby well-studied extragalactic CMZs to provide the first robust statistical assessment of CMZ molecular cloud (complex) properties (mass, line width, size, pressure, timescales etc.) and correlate these with global CMZ and galaxy properties to determine whether local processes (i.e. stellar feedback) or large-scale environment control their star formation activity and answer if the unexpected properties of our own CMZ are unusual or common. Further we will quantify if and how central AGN and starbursts alter CMZ cloud properties, and thus regulate subsequent star formation. This comprehensive study will provide the urgently needed data to distinguish between theories for CMZ star formation that either argue for a highly time-variable evolution caused by local processes or a more steady-state evolution regulated by the large-scale environment. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2024-10-25T16:14:24.000 |
| 4130 | 2023.1.00121.S | 0 | A multi-phase view of the gas cycle in the innermost regions of nearby AGN | Radiation-driven fountain models of molecular tori and their associated outflows predict a complex nature for the neutral gas reservoir located in the inner tens of parsecs of AGN. We propose to image with a spatial resolution of 0.1"(7-13pc) and a Largest Angular Scale goal of 4"(300-500pc) the CI line and its underlying continuum emission of 8 nearby Seyfert galaxies to map the diffuse atomic gas component and the dust continuum emission from the tori up to the circumnuclear disks (CND) of our targets. Previous publicly-available ALMA observations of our sample revealed an order of magnitude range in the nuclear-scale dense molecular gas concentrations derived from the CO(3-2) line, as well as a wide range of properties of their tori. Our candidate sources are representative of different evolutionary stages of the AGN feeding-feedback cycle. This proposal aims at gaining a multi-phase view of the gas cycle by incorportating tracers of lower-density neutral gas, which will provide neatly different constraints to numerical simulations on the imprint left by AGN feedback locally on the tori and on the larger spatial scales of the CND of Seyfert galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-09-23T20:30:37.000 |
| 4131 | 2011.0.00351.S | 0 | First detection of Hydrogen recombination lines toward an ionized jet arising from a high-mass protostar | We propose to observe hydrogen recombination line (HRL) emission from the triple radio continuum source associated with IRAS 16532-3959, thought to correspond to a luminous (7.0 x 10^4 Lsun) young high-mass protostar. The triple source consists of a recently discovered central ionized jet and two outer lobes, which signpost shocks resulting from the interaction of the jet with the surrounding medium. The capabilities provided by ALMA Early Science enable for the first time measurements of the kinematical and dynamical properties of jets and lobes and link their energetic properties with those of larger scale phenomena such as bipolar molecular outflows. IRAS 16532-3959 is the most massive protostar known to be associated with a collimated jet and is therefore an excellent first target to be included in the much-anticipated first round of ALMA studies of jets and outflows. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2014-02-08T08:30:00.000 |
| 4132 | 2019.2.00157.S | 0 | No disk is an island: exploring possible late stage infall on disks in the Lupus clouds | The current text-book description of how protoplanetary disks evolve assumes that, after the dispersion of the protostellar envelope, disks are isolated from the environment. In particular, no late infall of material from the molecular cloud onto the disk is expected in the Class II phase. Detecting such an infall is mainly hampered by the difficulties in carrying out observations at intermediate size of about thousand au, ~5 arcsec, the scale between the leftover molecular clouds and protoplanetary disks. These sizes are too small for singledish telescopes and largely filtered out by interferometry. However, there are indications from Herschel and scattered light images, CO maps, and theoretical predictions that infall onto disks can continue well into the Class II phase. Detecting such an infall will greatly change our view of star formation and disk evolution, and help to solve some of the current open questions in the field, such as the missing mass budget in planet formation. We propose ACA mosaics of 4 prototype disks and their environment in the Lupus cloud to reveal the structure and kinematics of the kilo-au environment with much greater details than before. | Low-mass star formation | ISM and star formation | 2023-02-12T00:00:00.000 |
| 4133 | 2017.1.00917.S | 25 | The Nature of the Central Disk in V Hya: A Carbon Star Ejecting High-Velocity Bullets | The carbon star V Hya is experiencing heavy mass loss as it undergoes the transition from an AGB star to a bipolar planetary nebula (PN), and is possibly the earliest object known in this brief phase, which is so short that few nearby stars are likely to be caught in the act. Our STIS/HST data show a 25-yr history of high-velocity (>200 km/s) bullet-like ejections from the star. SMA CO observations with ~3.5" resolution also reveal an extended high-velocity, collimated outflow (aligned E-W) and a N-S elongated dense waist (size 8" in CO 3-2) on ~100-250 yr timescales. Our coronagraphic polarimetric imaging at 1 micron shows an inclined disk of size 0.6" (or 240 AU) at the center of the waist. We propose to observe the CO J=3-2 line and 0.87 mm dust continuum in V Hya at 0.1" resolution to (a) determine whether this disk is rotating or expanding, and to constrain its mass, (b) study CO bullets close to the central source. These observations offer us an unprecedented opportunity to test binary interaction models for making the jet engines that launch the jet-like outflows that produce bipolar PNe outflows, and the disks that are the launch-sites of these outflows. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-05-27T17:11:45.000 |
| 4134 | 2019.1.00097.S | 8 | A Multi-wavelength Perspective of Hot Water around Massive Protostars: AFGL 2136 IRS 1 | ALMA has recently provided an unprecedented view of massive star formation by revealing the distribution and dynamics of hot gas in close proximity to one object (Ori source I) via observations of emission from H2O and SiO, which trace a rotating disk and bi-polar outflow. Observations of massive protostars in the near-to-mid infrared indicate a large amount of hot, dense gas traced by absorption of molecules such as H2O, HCN, and C2H2, but these pencil-beam studies lack information about the distribution of this gas. It is tantalizing to speculate that structures similar to those observed in Ori source I are responsible for the molecular absorption features observed in other sources, but there is currently no source where both the requisite ALMA emission maps and IR absorption spectra have been observed. We propose ALMA observations of H2O emission lines toward the massive protostar AFGL 2136 IRS 1, which shows strong H2O absorption in the IR. The sub-mm and IR observations will provide complementary information about the process of massive star formation, and will pave the way for interpretation of future IR observations made with JWST. | High-mass star formation | ISM and star formation | 2022-06-22T18:59:58.000 |
| 4135 | 2022.1.00209.S | 42 | Characterizing the physics and chemistry related to accretion shocks in protostars | In the low-mass star formation process, infalling material from the envelope meets the Keplerian disk and accretion shocks are produced. This is followed by an increase of the dust temperature and sublimation of molecular species into the gas-phase that, otherwise, will remain locked on dust grains. Although accretion shocks are predicted by theoretical models, only few protostars show evidence of these shocks at the disk-envelope interface and it is still not well understood if the observed shock-related species are being formed entirely on dust surfaces and then sublimated, or if they are formed in the gas-phase. We propose to observe a young protostar, IRS 44, at 0.1" that has been associated with accretion shocks from SO2 observations. We will observe multiple transitions of SO, CS, OCS, H2S, and H2CO, and assess their excitation conditions. The comparison between these molecules will clarify if SO2 is formed in the gas-phase or if it is directly desorbed from dust grains, or a combination of both. This proyect will provide clues about the chemical complexity that accretion shocks could generate and their implications on the material available for planet formation. | Low-mass star formation | ISM and star formation | 2024-06-06T04:22:27.000 |
| 4136 | 2015.1.01207.S | 107 | Diagnozing Protoplanet Formation in Protoplanetary Disks | We propose to observe SO and H2S lines at band 6 with high sensitivity in order to diagnose protoplanet formation in protoplanetary disks. It has been suggested that orbits of planetesimals are excited via formation of protoplanets in the disks. Highly excited planetesimals will cause bow shocks in the surrounding gas. Due to the shock heating, icy planetesimals will evaporate and comet-like components will be spread out into the gas in the disks. SO and H2S are the most plausible target molecules which can trace the icy planetesimal evaporation. The best lines for detection are selected based on our simulations of the line flux densities using detailed physical and chemical models of protoplanetary disks, Statistics of exoplanets suggest that planet occurrence around solar-type stars is more than 20%. We will observe 10 protoplanetary disks in the Taurus molecular clouds and make constraint on occurrence of protoplanet formation in the disks. Our proposed observations will fully bring out ALMA's capability of high sensitivity and contribute to our deeper understanding of planet formation theory. | Disks around low-mass stars | Disks and planet formation | 2017-12-21T01:08:05.000 |
| 4137 | 2023.1.01042.S | 0 | Is Age Just A Number? Investigating the Evolution of Gas Mass and Composition in Late-stage Protoplanetary Disks | The evolution of the mass and chemical composition of the gas in protoplanetary disks determines the size and chemical composition of planets that can form within them over time. Characterizing the gas properties of disks in populations of different ages is therefore important for constraining planet formation timescales. We propose to measure molecular emission from several key gas tracers including CO, 13CO, C18O, C2H, HCN, and N2H+ in 20 late-stage protoplanetary disks in the 5-10 Myr-old Upper Scorpius star-forming region. These observations will provide the dataset required for a statistical comparison with the observations of 80 disks (20 per region) from four younger (1-3 Myr old) star-forming regions carried out by the ALMA Disk-Exoplanet C/Onnection (DECO) Large Program. Through this comparison we will be able to search for changes in disk gas masses and elemental ratios (C/O, C/H, O/H) with age, evaluating the extent of disk evolution occurring in the later stages of the disk lifetime (for ages greater than a few Myr). Such observations are required to study the chemical evolution of the gas in late-stage disks, complementing both the DECO and AGE-PRO Large Programs. | Disks around low-mass stars | Disks and planet formation | 2025-01-29T20:16:50.000 |
| 4138 | 2015.1.00992.S | 8 | Zooming into a massive "hourglass": where is the smoking gun of magnetic braking? | How high-mass stars form remains poorly understood. Characterizing the role of magnetic fields is a fundamental step toward a complete theory of high-mass star formation. With an observational campaign made with the SMA, we detect an hourglass magnetic field aligned with the outflow/rotation axis in high-mass star forming region G240.31+0.07. While the "hourglass" on the 0.3 pc scale is consistent with the classic theory of star formation, it brings about great barriers to the observed fragmentation and potential disk formation in the inner part of the core. We predict that the field would be dominated by a toroidal component on the 0.05 pc scale, producing a field-rotation misalignment which has important implications to follow-up fragmenation and disk formation. To test our hypothesis, we propose for ALMA observations of the polarized dust emission at a 0.5" resolution, aimed at resolving the magnetic field structure on the 0.05 pc (~2") scale. | High-mass star formation | ISM and star formation | 2018-03-02T00:44:21.000 |
| 4139 | 2022.1.00908.S | 0 | Searching for CPDs and embedded planets in the transition disk EM* SR24S | For decades, astronomers have sought the detection of proto-planets embedded in their natal disks as they can provide invaluable constraints on planet formation. Protoplanetary disks with large dust cavities (a.ka. transition disks) have long been suspected to be formation sites of giant planets. The direct detection at IR and mm wavelengths of protoplanets and a circumplanetary disk (CPD) within the cavity of the PDS 70 transition disk system confirmed this suspicion. CPDs are very faint at submm wavelengths (e.g., 0.1 mJy in Band-7). Therefore, detecting them requires very deep observations of very promising targets. Embedded proto-planets can also be identified by kinematic searches of local deviations from Keplerian rotation at a high spatial and spectral resolution, which also require deep ALMA observations. Here we propose very deep (15 microJy continuum rms) Band-7 observations at 30 mas (4 au) resolution of the transition disk EM* SR24S, an extremely promising target, to look for circumplanetary disks within its 30 au dust cavity. The correlator setup also includes 12CO and 13CO lines at 0.1 km/sec resolution for kinematic searches of embedded protoplanets. | Disks around low-mass stars | Disks and planet formation | 2024-12-11T00:19:12.000 |
| 4140 | 2022.1.00955.S | 25 | The nature of ALMA-revealed substructure in submillimeter-bright galaxies: A kinematic study | ALMA has now provided the first detailed images of the dust-obscured star formation in submillimeter-bright galaxies a population of high-z, highly star-forming galaxies which remain poorly understood. These high-fidelity 870um continuum images reveal strikingly detailed substructures which have been alternately interpreted by various studies either as 1) bars, rings, clumps and spiral arms, or 2) evidence for mergers. Unfortunately, crucial kinematic information is lacking, rendering us unable to distinguish between these scenarios. Here we propose high-resolution (0.2 arcsec/1.5 kpc) CO(5-4) observations in four sources with confirmed bright CO luminosities. Thanks to its tight, linear correlation with IR luminosity, the CO(5-4) line is an ideal tracer of the dense gas directly fueling the dust-obscured starbursts. These observations will provide the missing kinematic information needed to confirm/refute the interpretation of the intriguing morphologies seen in these sources. Together with the approved JWST Cycle 1 NIRCam+MIRI imaging, this proposal will provide the best view to-date of these elusive high-z galaxies. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-06-09T21:35:34.000 |
| 4141 | 2013.1.00368.S | 7 | Atomic carbon in nearby active galaxies: Studying [CI] in NGC253, NGC1068 and Arp220 | Exploiting the new capabilities of band8 in Cycle2, we propose to map for the first time the [CI] emission in three nearby prototypical galaxies, the starburst galaxy NGC253, the Seyfert galaxy NGC1068 and the ULIRG and merger Arp220, at unprecedented subarcsecond angular resolution and sensitivity. We aim to evaluate the promising potential of [CI] emission as alternative and equal tracer to CO of the interstellar medium in our currently best templates of nearby active galaxies. How similar is the [CI] emission to that of CO in these environments? Are there differences in the [CI] properties between different activity types (NGC1068 vs. NGC253) and different star formation efficiencies (NGC253 vs. Arp220)? What are the effects of shocks onto [CI]? The proposed observations will further allow us to build up templates for the high-z galaxy population. For the latter, [CI] observations are booming thanks to increased sensitivities of current-day (sub)millimeter observatories and redshifted [CI] emission into atmospherically less constrained frequency windows. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-08-07T11:05:20.000 |
| 4142 | 2013.1.00813.S | 4 | Mapping Warm Molecular Gas in Luminous Infrared Galaxies: Arp 220 and NGC 6240 | Herschel observations of nearby star-forming galaxies have determined that the warm component of the molecular gas traced by the high-J CO lines dominates the luminosity and hence the energy budget. Our high spatial resolution ALMA observations of the CO J=6-5 line in Arp 220 resolved the morphology of the warm molecular gas for the first time on a much finer scale than ever before, revealing interesting and unexpected features. Multiple components are seen in the resolved ALMA observations, clearly suggesting that modeling galaxy-integrated CO rotational lines is inadequate for deriving the detailed excitation and physical conditions of the gas. High spatial resolution observations of multiple CO transitions are therefore needed to compare the morphology for different CO transitions and model the various components of the molecular gas on a pixel-by-pixel basis. Therefore, we request maps of CO J=4-3 in Arp 220 and CO J=6-5/3-2 in NGC 6240; due to its similarity to Arp 220, this galaxy will allow us to determine whether the warm gas morphologies that we are seeing are peculiar to Arp 220 or may be characteristic of merging luminous infrared galaxies. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2016-10-13T20:36:48.000 |
| 4143 | 2018.1.01318.S | 30 | Unveiling the accretion geometry in rare jet driven O-type protostar W42-MME | In order to observationally access the existing accretion based massive star formation models, the proposal aims to probe the inner most circumstellar geometry in a rare massive young stellar object (MYSO) jet-outflow system. The target W42-MME is one of the rare newly discovered O-type protostars at its early formation stage prior to an ultracompact HII phase. With no radio counterpart, W42-MME appears driving a parsec-scale H2 outflow and a highly collimated infrared jet in the inner 4500~AU. With the proposed high resolution imaging experiment, we aim to examine in detail for the first time the morphological and kinematical structure of the molecular gas immediately associated and surrounding this rare jet-outflow system near the O-type protostar. The proposed goal can be accomplished by high resolution molecular line observations at resolution of ~0.27" (or a thousand AU scale), which are lacking. The case study will provide further constraints to the roles of collimated jets/outflows in the massive star formation concerning the disk-mediated accretion, and will provide more insights how radiation pressure channels out in the most massive stars. | Outflows, jets and ionized winds | ISM and star formation | 2020-08-22T09:29:44.000 |
| 4144 | 2017.1.00755.S | 76 | Towards a census of star-formation since z~6 with ALMA-1.1mm | We propose to carry out a wide (10'x6.8') and deep (128 microJy rms) ALMA 1.1mm survey in GOODS-South. The combined power of ALMA and Herschel will probe the dust (hence also gas) content and SFR (hence SFE=SFR/Mgas) of galaxies out to z=3.5. It will open a new window on previously undiscovered dusty star formation out to z~6-8, provide the missing link between the obscured and unobscured Universe and permit statistical studies of galaxy populations via detections and stacking. It will reach a complete census on the cosmic SFR density of M*>4x10^10 Msun galaxies over z=0-6 with 0.15 dex uncertainty. This survey of the central CANDELS-Deep / Herschel-Ultradeep region of GOODS-S will have legacy value for astronomers worldwide. Our team brings together astronomers with extensive experience with the GOODS-S multi-wavelength dataset, especially Herschel, JVLA, HST and Chandra. Our original Cycle 3 survey was executed at 4x higher resolution (0.2") than requested, leading to a net loss of a factor 7 in the detection rate and substantial S/N degradation for stacking measurements. Carrying out this survey at 1.3" will firmly establish ALMAs capabilities for contiguous deep-field mapping. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2020-06-19T15:28:06.000 |
| 4145 | 2017.1.00461.S | 75 | Revealing the roles of filamentary clouds in GMC evolution of M33 | Recent ALMA observations of molecular clouds suggest that molecular gas becomes highly filamentary at sub-pc scale and the collision/interaction of such filamentary structures may drive the massive star formation. We propose to observe 12CO(2-1), 13CO(2-1), and C18O(2-1) emission lines toward three giant molecular clouds (GMCs) in one of the nearest spiral galaxy M 33 to investigate the roles of the filamentary structures of molecular gas in the massive star formation. The target GMCs are: GMC-8, the most massive GMCs in M 33 but with inactive star formation; NGC 604, one of the most luminous giant HII region in the Local Group with young stellar clusters; and GMC-16, associated with small HII regions and old (10 - 30 Myr) clusters. Based on ALMA observations, we investigate the differences in (1) the filamentary structures and their spatial overlapping, and (2) physical quantities and properties of clouds (size, linewidth, mass, column density, virial parameter, and mass fraction), among the target GMCs. Finally, we aim to understand the evolutionary sequence of GMCs and the star-formation process in terms of filamentary structures and their interactions in molecular clouds. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2019-11-06T00:39:57.000 |
| 4146 | 2019.1.00245.S | 160 | Confirmation of a sample of pre- and proto-substellar objects in Lupus molecular clouds | The nearby southern molecular clouds Lupus I and III are ideal laboratories for studying the formation processes of sub-stellar objects. Our group (the SOLA team) has identified a set of pre- and proto-substellar candidates using ALMA Cycle 3 data at 1.3 mm. We propose observations in Band 7 and Band 3 in continuum and spectral lines in an attempt to confirm the real nature of these candidates as pre- and proto-brown dwarfs and clarify their apparent association with the Lupus clouds. The proposed observations will allow us to measure accurately the mass of the dust envelopes and dust disks surrounding these objects, to assess their dynamical state (e.g. transient versus self-gravitating condensations), and reveal the presence of large dust particle (millimetre to centimetre sizes). ALMA observations of this sample have the potential for the first time to provide a general picture of how substellar objects form and evolve, from pre-brown dwarf cores to proto-brown dwarfs. This proposal, requesting 6.1 hours time, will provide an important insight on the formation of brown dwarfs. This is a resubmission of a Cycle 6 accepted proposal. | Low-mass star formation | ISM and star formation | 2021-04-06T21:19:32.000 |
| 4147 | 2016.1.01216.V | 0 | Probing the active collimation region of the relativistic jet in 3C 273 | We propose an ultra-high resolution, full-polarimetric observation of 3C 273 at 86 GHz with GMVA+ALMA. The primary objective is resolving the transverse structure at the inner ~10^5 Rs of the quasar jet for the first time by including ALMA. The resolved profile of the jet collimation can address the location of the launching point of the visible jet in quasars. Secondly, we aim to obtain the deepest linear polarization image of this jet-collimating region with the highest angular resolution ever. This enables probing the spatial distribution of the Faraday Rotation Measure (RM) at inner ~10^4-10^5 Rs, combining with high-sensitive observations with VLBA+Effelsberg at 15/22/43 GHz already proposed. The obtained RM distribution will provide unique information of the magnetized plasma distribution surrounding the jet, combining with previous lower frequency observations. Furthermore, the RM-corrected linear polarization map and the transverse RM distribution will provide the three-dimensional magnetic-field configuration of the actively collimating jet. Overall properties revealed in the proposed observations will constrain the global environment around the quasar jet. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-10-21T09:39:23.000 |
| 4148 | 2023.1.01732.S | 0 | Direct Constraints on Planet Formation with the VLA and ALMA | We propose joint VLA and ALMA observations in 6 bands to directly constrain grain growth and multi-size grain populations in 25 T Tauri disks in Upper Scorpius. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 4149 | 2013.1.00670.S | 2 | Investigation of Gas-to-Dust Mass Ratio in the Asymmetric Disk around HD 142527 in Band 3 | We propose Band 3 observations of the asymmetrically gapped disk around the Herbig Fe star HD142527 in 13CO/C18O J=1-0 and dust continuum at 100 GHz. Our group made Band 7 observations of the disk in Cycle 0. The continuum emission shows strong asymmetry and is extremely bright (Tb=24 K at 156 AU from the star). There are two possible situations that account for these results: (1) the disk is in gravitationally unstable state to form a gaseous planet, or (2) dust grains are highly accumulated to form a rocky planetary core. The key parameter to judge which is the case is gas-to-dust mass ratio (g/d). Our analyses of g/d with disk modeling suggests that g/d in the regions of lowest surface densities may change significantly in radial direction. However, g/d in most regions of the disk cannot be determined solely from Band 7 observations, because J=3-2 lines of 13CO and C18O are optically thick. The disk should be much more transparent to the J=1-0 lines of CO and dust continuum emission in Band 3, allowing us to better estimate g/d and size distribution of dust particles in the entire regions of the disk. | Disks around low-mass stars | Disks and planet formation | 2016-11-26T04:20:11.000 |
| 4150 | 2017.1.01713.S | 75 | Confirmation of the first radio-selected galaxy at the dootstep of the EoR | Radio galaxies are ideal probes of galaxy assembly at high redshifts, tracing systems with very high star-formation and pinpointing the build ups of massive galaxies and proto-clusters. Radio galaxies are also prime tracers of AGN activity. But the identification of these radio sources close to the Epoch of Re-ionization is yet to be achieved, although we know AGN exist up to z~7 and theory predicts a significant number of such sources at z>6 well within the reach of current radio surveys. The problem might not be the sensitivity of current surveys but rather finding a way to identify them within the current population. Using a radio selection criteria with FIR information, we have recently obtained an IRAM-30m spectrum indicative of a z=6.01 for a high-z radio selected candidate. We propose here to confirm the z of this outstanding source, becoming the highest-z radio selected galaxy discovered so far, at the end of the EoR. By realizing the potential of radio-selection to identify the highest z sources, this detection will also motivate the perfecting of strategies for the upcoming generation of whole-sky deep radio surveys such as ASKAP-EMU and Westerbork-WODAN, and SKA itself. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2019-04-30T22:51:35.000 |
| 4151 | 2015.1.01054.S | 58 | Shedding Light on Distant Starburst Galaxies Hosting Dust-Obscured gamma-ray Bursts | Studies of distant starburst galaxies hosting GRBs offer unique insights into extreme star-forming regions during early epochs. In particular, 25-40% of all GRBs show a suppressed optical to x-ray ratio in the afterglow. A likely explanation is that they originate in dusty galaxies, which are commonly missed in optical surveys. We have carried out a successful program in ALMA Cycle 0 to observe the galaxy hosting the dark GRB 080607 at z = 3.036. We obtained a marginal detection of its 345 GHZ continuum, placing it at the faintest end of the dusty galaxy population. This indicates that the large extinction (Av ~ 3) in the afterglow is confined along a dusty sight line, contrary to the expectation of the host galaxy itself being dusty. Here we propose to conduct a systematic study of nine galaxies hosting dust-obscured GRBs at z > 1.5 based on observations of their 345 GHz continuum. All nine galaxies have spectroscopic redshifts to confirm that the suppressed optical fluxes are indeed due to extinction, rather than IGM absorption. The proposed imaging will allow us to characterize the global dust content of the host galaxies in a broader context of the dusty galaxy population. | Starburst galaxies, Gamma Ray Bursts (GRB) | Active galaxies | 2017-08-31T09:18:41.000 |
| 4152 | 2013.1.00227.S | 8 | ALMA Detection of a Superwind-Driven Shocked Shell Associated with the Proximate DLA of SDSS J124020.91+145535.6 at z=3.1 | In order to investigate the origin of damped Lyman alpha absorption systems (DLAs) at high redshift based on the superwind-driven shocked shell model (Taniguchi & Shioya 2001), we propose to observe a proximate DLA (PDLA) found in the line of sight to the quasar SDSS J124020.91+145535.6 at z=3.1 studied by Hennawi et al. (2009). In this PDLA, an extended Ly alpha nebula is associated with a size of 5 arcsec (=38 kpc), being identified as a Lyman alpha blob (LAB). Since one of plausible origins of LABs is a superwind-driven shocked shell (Taniguchi & Shioya 2000), this PDLA is an ideal laboratory to prove this idea. Here we propose to observed this PDLA in [C II]157.74 emission in the Band 8 on ALMA. Our main science goals are to detect [C II]157.74 emission from the PDLA host and the shocked shell causing DLA features and to investigate their dynamical properties in detail. This observation provides us a bland-new approach to understand the nature of high-redshift DLAs. | Damped Lyman Alpha (DLA) systems | Cosmology | 2017-01-22T14:04:05.000 |
| 4153 | 2023.1.00189.S | 0 | Mapping the dustiest galaxies in the Universe with ALMA+JWST | The nature of the most highly star-forming galaxies in the Universe has long been a mystery. Despite forming stars at 100-1000 M/yr, these z~2.5 dusty star-forming galaxies (DSFGs) are plagued by extreme dust obscuration, leading to decades of debate on whether major mergers are necessary to trigger their starbursts. Excitingly, this is now changing thanks to JWST. The >200 hr COSMOS-Web Treasury Program is providing multi-band NIRCam(+MIRI) imaging of the largest sample of DSFGs of any public/GTO program--revealing their previously hidden stellar emission--but comparable imaging of the prolific starbursts is missing. We propose 0.15'' (~1kpc) 870um imaging of 80 (>3mJy) DSFGs in this area. This will provide the first statistically significant sample of DSFGs with matched-resolution imaging of the stars *and* current star formation necessary to 1) definitively reveal their morphologies; 2) derive robust physical parameters and test SED fitting assuming energy balance; 3) create resolved maps of M*, SFR, sSFR, etc. to test the latest cosmological hydrodynamic simulations and constrain the evolutionary pathways linking DSFGs to their proposed descendants: massive local ellipticals. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 3000-01-01T00:00:00.000 |
| 4154 | 2017.1.01301.S | 162 | The structure of z>6 quasar host galaxies | Our recently completed ALMA snapshot survey of 27 z>6 quasars has resulted in a very high detection rate of both the [CII] line and the underlying continuum in the quasar hosts. We here request 'moderate' resolution (0.25", 1.5 kpc) imaging of a subset of bright sources from this survey. Our observations are designed to differentiate between very compact vs. extended [CII] (and dust continuum) emission in the quasar host galaxies. Previous imaging of a few quasar hosts at similar redshift point at strikingly different morphologies, with major implications for deriving star formation / gas surface densities, and dynamical masses. Our proposed observations of this sample of bright quasars will also inform us regarding the relative frequencies of these structures (compact vs. extended). They will also help us to select targets with very compact and bright emission for future, even higher-resolution imaging that will start to resolve the sphere of influence of the central supermassive black holes. Given ALMA's unparalleled sensitivity, the requested band 6 observations can be executed in less than 9 hours of observing time. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-10-09T21:18:01.000 |
| 4155 | 2015.1.00662.S | 130 | The heating effects of the HH46/47 outflow | How energy is transported across outflow cavity walls onto the cold surrounding cloud material is virtually unknown. Although existing observations readily show the cavities and the cavity walls, they lack the spatial resolution to study the precise location and structure of the surface PDR through observations of the warm molecular and/or atomic gas. Clear variations in the gas distributions along the flows have been revealed. A large number of possible scenarios have been proposed for the heating effects. Most likely, multiple scenarios actually coexist within one flow, depending on local conditions and internal UV radiation. The best-studied outflow to date is HH-46/47. We propose to use ALMA to observe 17-21 positions along its red lobe. By targetting CO 65 and [CI] 1-0 transitions at 0.3 spatial resolution, the emission profiles of both the molecular and atomic gas located within or behind the surface PDR and within the cavity will be spatially and spectrally resolved. This allows us to directly image the structure of the cavity wall, unambigiously determine the gas distribution of the PDR layer(s) and thus derive how energy is transported across the cavity wall. | Outflows, jets and ionized winds | ISM and star formation | 2017-10-14T04:47:47.000 |
| 4156 | 2018.1.01533.S | 56 | Molecular gas content of the most common high-redshift radio galaxies | AGN feedback is now recognized to be a major mechanism regulating galaxy growth, but we still largely ignore how AGN affect star formation in massive host galaxies, especially during their major growth period at high redshift. We will use ALMA to measure the molecular gas content and kinematics in the most abundant, moderately radio-loud AGN host galaxies at z~2, which may represent a common phase in the evolution of massive, dusty, high-z starbursts. SINFONI shows that these galaxies have very turbulent ionized gas powered by the radio jets, like the most powerful sources, but clear outflow signatures are missing, suggesting these AGN must act on star formation in another way for feedback to work. With ALMA we will observe CO(4-3) and [CI] 1-0 in parallel down to log M/Msun ~9, and measure their gas masses and gas kinematics. We will test whether the high turbulent motions seen in ionized gas or perhaps even outflows are present in the molecular gas, as required if the AGN affects star formation in these galaxies, and constrain the ratio of warm ionized to molecular gas mass, which is strongly enhanced in the most powerful sources, and potentially a sign of strong AGN heating. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2020-08-09T10:14:42.000 |
| 4157 | 2018.1.01851.S | 136 | The impact of O-type stars on gas dynamics: The case of the G316.75 massive-star forming ridge | Newly formed (proto)stars inject energy and momentum back into the interstellar medium which, in turn, affects star formation. This feedback loop is believed to regulate the rate at which galaxies form stars in the Universe. There is though a high degree of uncertainty regarding the exact impact that stellar feedback has on individual molecular clouds, down to individual star-forming cores. Observationally, the major hurdle in providing robust constraints on the dominant effect of feedback is that we usually have access to the gas properties only after it has been impacted. Here, we propose to use ALMA to investigate the impact of stellar feedback on the dense gas kinematics of the massive G316.75 O-star-forming ridge. This cloud has the unique property to be half IR-dark and half IR-bright, with two O-type (proto)stars already formed in it. Here, we will use the N2H+(1-0) and HCO+(1-0) emission lines to compare and contrast the properties of filaments and cores in both parts of the ridge in order to quantify the impact of feedback: on filament kinematics; on the infall velocity statistics of cores; and on the formatoin of more massive cores/stars. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-10-17T20:10:07.000 |
| 4158 | 2016.1.01277.S | 17 | Dissecting a normal star-forming galaxy at z=6 - unique insights from the host of GRB 130606A | Understanding the formation and growth of galaxies in the first billion years of the universe is a primary goal of cosmology. Recently we have located the host of GRB 130606A (z=5.913) in deep HST observations, the brightest of only three hosts detected in emission at z>5 to date. With a rest-UV luminosity of ~0.6L*, it is likely representative of the galaxies which dominated total star formation in the era of reionization. High S/N spectroscopy of the GRB afterglow furnishes us with detailed ISM abundances, cold gas column, dust depletion and internal kinematics for this magnitude 26 galaxy, information that will generally not be available for galaxies selected by conventional LBG/LAE techniques even with JWST. We are also in the process of obtaining deep optical spectroscopy with VLT to quantify its Ly-alpha characteristics. Here we propose to search for [CII] and dust continuum emission of the host, with the aim of understanding how its ISM properties in emission relate to what is seen in absorption, and to enable comparison with brighter and more massive galaxies that have been studied by ALMA in this era and to similar galaxies in the lower redshift universe. | Lyman Break Galaxies (LBG), Gamma Ray Bursts (GRB) | Galaxy evolution | 2017-11-25T20:54:34.000 |
| 4159 | 2022.1.00212.S | 405 | A Comprehensive [CII] Survey of Herschel-Selected Starbursts at z=3-6 | Based on a survey of the most luminous massive starburst galaxies found in >1000deg2 observed with Herschel, we have obtained a comprehensive sample of >300 sources with secure, CO/CI-based spectroscopic redshifts. Here we propose to detect [CII] 158um emission from the star-forming ISM at z=3-6 in all 102 galaxies in our sample that are observable with the ACA, i.e., six times as many as in the largest massive starburst samples currently available. In combination with the rich suite of diagnostics already available, this study will provide critical insight into the physical properties of the ISM that set the conditions for star formation for a statistically significant sample, including a study of feedback based on the line profiles. Based on 9 systems in our sample for which we have already obtained <=1kpc resolution [CII] imaging with the ALMA 12m array, the ACA data will also provide a critical test for the potential presence of low surface brightness emission on >5-10kpc scales due to an enriched cold circum-galactic medium missed by high-resolution studies, as has been suggested to be present in star-forming galaxies in the early universe by some recent theoretical work. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-03-03T14:01:34.000 |
| 4160 | 2016.1.01228.S | 40 | Twin disks in FU Ori: Episodic accretion via binary interactions? | FU Oris are low-mass pre-main sequence stars characterized by dramatic outbursts during which stars may gain a significant portion of their mass. Proposed mechanisms which could drive these episodic accretion events include gravitational and thermal instabilities, disk fragmentation, forming planets and stellar encounters. Most interestingly, the archetypical FU Ori system, FU Oriorins itself, is a known binary composed of two disks separated by only 0.5" that have been detected in gas and dust during Cycle 0. These data, although reaveling clear signs of interaction in the system, suffered from low sensitivity and poor resolution and the disks are only partially resolved. How does this binarity and mass exchange/interaction affect the scenarios which aim at explaining episodic accretion? We propose to map the gas and dust in FU Ori at 50 mas resolution in band 6 to build a comprehensive picture of the dynamics of the system. We aim to capture dynamic interaction through CO isotopologue kinematics and compare these with dedicated hydrodynamic simulations. Mapping both disks in continuum is also a pressing need to distinguish between outburst mechanisms. | Low-mass star formation | ISM and star formation | 2018-10-09T07:31:37.000 |
| 4161 | 2017.1.00496.S | 273 | Mapping the molecular gas in jellyfish galaxies | We propose Band 3 and 6 ALMA observations in mosaic mode to observe the CO(2-1) and CO(1-0) in 4 galaxies undergoing violent interstellar-medium removal by ram pressure stripping ("jellyfish galaxies") in galaxy clusters at z=0.04-0.06. These clusters cover a wide range of cluster masses and intra-cluster medium conditions. Our targets are part of the ESO Large Program GASP (GAs Stripping Phenomena in galaxies with MUSE), that is gathering MUSE integral-field optical spectroscopy, HI JVLA imaging and Chandra X-ray data to investigate the physics that regulates the different gas phases and the star formation activity in galaxies suffering gas removal. Our APEX CO observations reveal large amount of molecular gas both in the disk and in the tails of these galaxies, up to 60kpc from the disk. We need ALMA resolution to study the molecular gas content of the numerous HII regions and complexes that are detected in Halpha in the stripped tails and in the disk, to determine the origin and kinematics of extraplanar molecular clouds, how their formation depends on the stripped gas and intracluster medium conditions, and the link between the various gas phases and star formation. | Spiral galaxies, Galaxy groups and clusters | Local Universe | 2020-02-06T09:00:41.000 |
| 4162 | 2022.1.01133.S | 5 | ALMA Observations of Dusty AGNs in Dwarf Galaxies | While AGNs have now been found in hundreds of dwarf galaxies, very little is known about the molecular gas and dust that can fuel and obscure the black holes in these objects. Here we propose sensitive, high-resolution (~0.1 arcsecond) ALMA Band 6 observations of 3 dwarf galaxies hosting dusty AGNs identified by their mid-IR colors, optical emission line ratios, and X-ray luminosities. We aim to directly detect the CO (2-1) line and dust continuum in the immediate vicinity of the AGNs and disentangle this emission from that of the host galaxies on larger scales. With the proposed observations, we will 1) determine the mass, morphology, and kinematics of the cold molecular gas in our target dwarf galaxies hosting AGNs, and 2) measure emission from the dusty tori at mm wavelengths and construct the AGN SEDs in combination with existing observations at infrared to X-ray wavelengths from WISE, HST, and Chandra. Ultimately, this project will provide valuable information on black hole feeding and feedback, as well as the panchromatic energy output of AGNs in the relatively unexplored low-mass regime. | Active Galactic Nuclei (AGN)/Quasars (QSO), Dwarf/metal-poor galaxies | Active galaxies | 2024-06-22T08:53:03.000 |
| 4163 | 2024.1.00015.S | 0 | SMM J0658: Probing Star-Forming Clumps and PDRs in a Highly Magnified ISM at z~3 | Bright photodissociation regions (PDRs) in nearby star-forming clouds serve as excellent laboratories for spatially resolving the detailed structure, physics, and dynamics of UV-illuminated matter in the ISM. However, conducting such studies becomes extremely challenging at high redshifts, as our best telescopes lack the resolution to resolve clumpy star-forming galaxies. We propose to use ALMA Band-4 to image the 12CO J=5-4 line in the lensed galaxy SMM J0658 at z = 2.7779 behind the Bullet Cluster, which exhibits one of the highest differential magnifications ever recorded at submillimeter wavelengths (up to 50). Taking advantage of the rich ancillary dataset, our objectives include: (1) providing an exquisite spatially resolved PDR description in the clumpy ISM of a 'normal' high-z galaxy, (2) determine the PDR radiation field and gas density in each star-forming clump using the 12CO J=5-4 line along with ancillary ALMA data. Additionally, the spectral setup will enable us to further constrain the redshift of an unidentified ring-like object detected at the location of the Bullet Cluster's BCG in various ALMA bands. | Starbursts, star formation, Early-type galaxies | Active galaxies | 3000-01-01T00:00:00.000 |
| 4164 | 2013.1.01165.S | 6 | Probing the Most Extreme Starbursts of Non-Interacting Nature | We propose high-spatial resolution observations with ALMA to spectroscopically map the molecular gas and dust in non-interacting extreme star formation environments (with rates larger than 50~M_sun/yr). Our HST imaging program of the Great Observatories All-sky LIRG Survey (GOALS) has recently spatially resolved double nuclei and tidal features in 88 nearby (U)LIRGs, corroborating the picture that most high-IR luminosity LIRGs in the local universe are major mergers. In this proposal we will focus on the few non-interacting LIRGs above L_IR > 10^11.6L_sun which may be more representative for extreme star formation environments at high red-shift. ALMA will spatially resolve the morphology of the gas components on a scale comparable with that of the HST. This will allow us to measure streaming motions and gas mass infall rates due viscous and gravitational torques exerted by nuclear spiral arms and bars. We will compare the star formation morphology and infall rates to those in normal star forming galaxies and low-luminosity AGN as probed by the NUclei of GAlaxy (NUGA) survey as well to those of interacting LIRGs. | Galactic centres/nuclei, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2016-10-08T20:34:48.000 |
| 4165 | 2017.1.00870.S | 5 | Unravelling the heating of the solar corona through the cooling | Thermal instability is a fundamental mechanism at work throughout the universe and has detailed observational consequences in the Sun. In particular, coronal rain (rapidly occurring plasma at coronal heights with chromospheric properties, i.e. partially ionised cool and dense) is the direct observational consequence of thermal instability in the solar corona. Increasing observational and numerical evidence suggest that its characteristics such as its thermodynamic state, the occurrence frequency and mass fraction in the corona, its morphology and dynamics are intrinsically linked to key aspects of the solar atmosphere and, in particular, to coronal heating. Thanks to its chromospheric nature, coronal rain is a unique ALMA observable produced in coronal loops, the basic building blocks of the solar corona. On the other hand, ALMA is unique in being able to firmly characterise the thermodynamic state and amount of coronal rain in the solar atmosphere. By investigating coronal rain with ALMA we aim at measuring the thermal inhomogeneity of the solar corona, thereby providing powerful constraints for coronal heating mechanisms and characterising the cool alter ego of the hot corona. | The Sun | Sun | 2022-10-01T00:00:00.000 |
| 4166 | 2011.0.00307.S | 0 | Tracing the dense, star forming gas and AGN feedback in z=2-4 galaxies via the shape of the CO line SED. | Recent HERSCHEL observations of the CO line SED in local IR luminous galaxies have demonstrated that the CO levels are excited at least up to the CO(13-12) transition and that the relative strengths of the J_up>10 transitions carries valuable information on the gas excitation and possibly signs of AGN heating. Our observations of z~4 QSOs support the interpretation that AGN heating has a significant influence on the shape of the CO SED at the highest CO levels but a contribution of the dense, star-forming gas is expected too. We here propose to obtain information on the shape of the CO SED for transitions between J=8-7 and 14-13 in the three best studied high redshift (z=2.5-4.1) galaxies observable with ALMA. With the observations we aim to study the effect of extreme star-formation and AGN heating on the intensities of the J_up>10 transitions at high redshift and to investigate the underlying excitation channels. The data will provide the first comparison sample to HERSCHEL observations in the local universe in less extreme environments. Our results will have impact on prime science goals for full ALMA array such as the observability of CO lines in galaxies at the epoch of re-ionisation. This project requires relatively short integrations which make it a highly suitable project for early ALMA high impact science. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2013-10-15T11:18:07.000 |
| 4167 | 2018.1.00528.S | 21 | Searching for CO-dark H2 gas in radio jets | Our recent discovery shows that cosmic-rays (CRs) and X-rays destroy CO by converting it to CI while the H2-gas remains unaffected. This challenges the widely used CO-to-H2 conversion method in extreme environments, especially in outflows associated with radio emission. These outflows are strongly magnetised, with high densities of CRs and X-rays. Recent ALMA detections of CO in outflows associated with radio jets indicate that H2 can exist in such extreme environments. Therefore, we propose CI 1-0 observations in the radio jets of Minkowski's Object and M87, where CO lines have been detected. We aim at i) Detecting hidden H2 reservoir in radio jets, ii) determining the degree of CI-CO concomitance, iii) Disentangle shock- and CR-/X-ray chemistry, iv) estimating H2 outflow mass, and v) estimating star formation efficiency along the outflow by comparing with CO-based measurements. This will be a key experiment for testing our theoretical predictions that CI emission in both radio jets would be much brighter than scaled from CO lines under normal conditions of molecular clouds. If confirmed, it will open a new window for detecting H2-gas under extreme conditions. | Outflows, jets and ionized winds | ISM and star formation | 2020-08-06T07:34:11.000 |
| 4168 | 2011.0.00175.S | 0 | Merging IR-Luminous Galaxies -- Arp 220 and NGC 6240 | We propose imaging in Band 7 (HCN, CS, H26alpha and continuum) at 0.5'' resolution and in Band 9 (HCN and continuum) at 0.25 arcsec resolution for the dense starburst regions of Arp 220 and NGC 6240. These unprecedented data will probe the distribution and dynamics of star forming gas and star formation activity in the dense disk structures to enable new theoretical understanding of the physics, dynamics, star formation activity and associated feedback in the most active and rapidly evolving galactic nuclei. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2013-11-05T21:53:00.000 |
| 4169 | 2021.1.00079.S | 21 | Atomic carbon in a prototypical barred-spiral galaxy | Atomic carbon (CI) has been suggested as a tracer of molecular mass alternative to CO, especially in high-redshift galaxies where cosmic rays can destroy CO, or in outflows where the optical depth of CO is unknown. However, the CI abundance over the H2 abundance varies with various other factors such as turbulence, cloud age, UV field, and density. How the CI abundance changes first needs to be understood in a nearby galaxy where the physical conditions are well known. We propose a large-area CI mapping of a barred-spiral galaxy M83 to study how CI/CO changes in various location of a galaxy, namely, a galactic center, bar, arm, and interarm. We will examine the variation of CI/CO with the influence of turbulence, cosmic rays, and UV photons. The CI data will be compared with large-scale maps of CO 1-0 and 2-1 already available. Our analysis will serve as a template for nearby and high-redshift galaxies as to when CI is a reliable molecular mass tracer. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2023-04-25T09:19:31.000 |
| 4170 | 2017.1.01555.S | 42 | Is Enceladus' Subsurface Ocean Life Sustainable? An Earth-Based Study of the Chemical Composition of Enceladus' Plume | Cassini INMS data indicate Enceladus plume composition consists of H2O, CO and/or N2, NH3, HCN, CH4, H2CO, H2S and some organic molecules such as CH3OH and C2H5OH, and possibly ketene and glycine. Identification of key species and trace compounds in the plume is thus critical as it can constrain theories for the internal constitution and composition of the subsurface ocean, and also, in the form of various simple organic molecules, provide biomarkers for the persistence of any subsurface life. To investigate whether Enceladus is life sustainable or not, it is crucial to study the chemical composition of Enceladus' subsurface ocean. With its superb sensitivity and angular resolution, ALMA offers us an opportunity for spectral confirmation of INMS identifications and precise measurements of molecular abundances in the plume. Our project will provide synergy between ground-based observations and in-situ measurements, and lead to insight into the potential of Enceladus as an abode for life. It will also yield important information into Enceladus' formation environment, the oxidation state of Enceladus' subsurface ocean, and the origin of the excess H2 released from hydrothermal vents. | Solar system - Planetary atmospheres | Solar system | 2019-06-14T15:31:31.000 |
| 4171 | 2022.1.01155.S | 72 | Characterizing the protoplanetary disks around young massive stars | Most stars in ALMA surveys of protoplanetary disks have stellar masses less than 2 solar mass. The few existing observations of higher-mass objects have found more massive and structured disks than those around low-mass stars, suggesting a higher incidence of giant planet formation. Hence, evidence is emerging that disks around higher mass stars evolve differently. Unfortunately, past observations of high-mass forming stars mainly targeted evolved objects (>3 Myr). This motivates a more complete survey to understand the disks around younger massive stars. We propose to conduct the first survey of disks around young (<3 Myr) massive (2-4.5 solar mass) pre-main sequence stars, targeting 34 carefully selected disks which will increase the amount of observed disks at this early stage by a factor of 7. This will allow us to provide a complete picture of the protoplanetary disk evolution in high-mass stars, from early ages to the main sequence. In particular, the proposed observations will allow us to study the mass reservoirs and disk sizes at these unexplored young disk stages. This is key for separating between different disk evolution scenarios and giant planet formation mechanisms. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2025-05-10T17:25:41.000 |
| 4172 | 2022.1.00089.S | 10 | Anatomy of molecular tori of Seyfert galaxies | The ALMA images of the 10-20pc-size molecular torus in the Seyfert galaxy NGC1068 have revolutionized the canonical pc-scale torus paradigm of unified AGN theories, also showing the presence of a multiphase complex kinematics. We propose to complete the mapping of the CO(3-2) and HCO+(4-3) lines and the 870micron continuum emission in the circumnuclear disks (CNDs) of the 7 targets for which there are images obtained at 7-13pc using now a spatial resolution of ~2-4pc. This project will expand by an order of magnitude the number of AGN observed with a spatial resolution and sensitivity akin to those achieved in NGC1068. These observations will enable the construction of 3D morpho-kinematic models of the torus: to study Keplerian rotation, inflow and outflow motions; to compare with predictions of state-of-the-art radiation-driven wind models and simulations; to derive BH masses in a key range of the M-sigma parameter space; and to map the torus-CND connection for the feeding budget in a representative sample of AGN. This is a resubmission of two accepted yet not-completed proposals to image with unprecedented resolution the ~40pc-size molecular tori in a sample of nearby AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-07-03T15:08:53.000 |
| 4173 | 2016.1.00694.S | 41 | AGN winds: combining insights from millimetre and X-ray observations | We propose ALMA high-sensitivity observations of the CO(1-0) emission line in two local Seyfert-LIRGs showing evidence of both X-ray ultra-fast (v~0.1c) nuclear winds and kpc-scale ionised outflows. These sources constitute a particularly interesting sample where to investigate the AGN feedback propagating from the inner accretion-disk to the interstellar medium up to kpc-scales. We aim at investigating the presence of large-scale molecular outflows produced by a blast-wave mechanism activated through the nuclear X-ray wind. Contrary to previous studies of AGN-driven molecular outflows, our targets are only moderately star forming, with SFR<10 M_Sun/yr, and have AGN luminosities close to the knee of the luminosity functions, well representing the sources where the bulk of AGN feedback is expected to be at place and dominate over the feedback from star formation. The synergy between X-ray and ALMA observations will allow us to test and extend to more typical AGNs the relation between the energetics and momentum flux of the molecular outflows and the fast nuclear disk winds, studied so far only in a few extreme ULIRG/QSO sources. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2021-07-14T18:02:17.000 |
| 4174 | 2021.1.00389.S | 111 | Deep [OIII] 88 um and dust continuum observations of two remarkably luminous galaxies at z ~ 10 | We propose [OIII] 88 um and dust continuum observations of two remarkably UV-luminous (MUV=-23) galaxies at z~10. Our targets are carefully selected from the brand-new COSMOS2020 catalogue equipped with deep and unprecedentedly-wide optical to near-infrared data, the best suitable to find the rarest, brightest galaxies. Our two candidates have 1) sharp Lyman break features; 2) IRAC detection; 3) tight photo-z solutions. The volume density of these objects is consistent with the bright-end of the UV luminosity function (UVLF) studies at z=9-10 that suggests a double power-law. We aim to identify these objects by [OIII] 88 um, the best FIR line to observe z>8 galaxies. This will be done with six tuning setups carefully chosen to cover mostly the entire photo-z range. A successful detection will confirm the power-law nature of the UVLF for the first time by spectroscopy. This has significant implication in the field of galaxy formation as they would represent a transition before significant dust attenuation and mass quenching. We will also directly observe the dust continuum, which is crucial to test the dust-poor hypothesis as the physical origins of the brightest galaxies. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-05-09T20:50:39.000 |
| 4175 | 2022.1.00499.S | 204 | Moving Past Small Number Statistics in Astrochemistry: A Molecular Survey of Two Dozen Hot Cores | Studies of chemical evolution have traditionally focused on a small number of exceptionally molecularly rich and bright sources due to the historical difficulty in detecting complex interstellar molecules. This small sample size biases our understanding of 'standard' chemical evolution, and prevents calibration of chemical models to standard conditions. Single-dish surveys that have attempted to address this issue by surveying substantially larger sample sizes have suffered from extreme beam dilution, due to the very small angular size of typical chemically rich hot cores. Here, we propose to exploit both the sensitivity and spatial resolution of ALMA to finish conducting a distance-limited survey of two dozen hot core sources. We target several spectral windows designed to provide the maximal scientific return, and will use the results to calibrate several of the industry-standard models and identify critical areas in which these models need refinement. | Astrochemistry | ISM and star formation | 2025-04-03T16:14:27.000 |
| 4176 | 2011.0.00780.S | 0 | The origin of molecular gas in the oldest gaseous debris disk system HD 21997 | Nearly all young stars harbor circumstellar disks, which initially serve as reservoir for mass accretion, and later may become the birthplace of planetary systems. These disks thought to evolve from gas-dominated primordial disks to debris dust disks on the timescale of less than 10 million years. In debris disks, only a very small amount of gas is expected, and indeed, only a few debris disks with a detectable gas component are known. In our preparatory APEX survey, we discovered that the 30 million-year-old HD 21997 exhibits molecular gas detectable at millimeter wavelengths. This is the oldest known gaseous debris disk, making it the best candidate for containing CO gas of secondary origin, produced by sublimation of planetesimals, photodesorption from dust grains, or vaporization of colliding dust particles. Here we propose to obtain the first spatially resolved interferometric continuum (at 870 micrometer) and line (at the J=2-1 and J=3-2 transitions of CO) observations with ALMA. Our goal is to understand the nature and formation process of the gas in this uniquely old gas-rich debris disk. In particular, we will (1) determine the structure and inclination of the dust disk; (2) measure the spatial distribution of the CO gas, test whether gas and dust are co-located, and compute the gas-to-dust ratio; and (3) map the excitation temperature and gas density throughout the disk. A primordial origin for the gas would pose a serious question to the current paradigm, because the age of the system significantly exceeds both model predictions for disk clearing and the ages of the oldest T Tauri-like or transitional disks in the literature. If a secondary origin is confirmed, the proposed observations will open the way to study the evolution of secondary gas in debris disks. | Disks around low-mass stars, Debris disks | Disks and planet formation | 2014-03-20T00:00:00.000 |
| 4177 | 2015.1.01074.S | 42 | Properties of a temperature-unbiased sample of Herschel 250um-selected galaxies at z >2.5 | We propose to observe 870 micron dust continuum of 200 Herschel 250micron-selected galaxies at z > 2.5 with ALMA Band 7. Our sample is unique in selecting infrared luminous galaxies in a manner unbiased by dust temperature, contrary to submillimeter-selected samples which prefer colder dust temperatures. The primary beam of ALMA at 870 microns is well matched to the 18 arcsec FWHM of the SPIRE 250 micron beam, making Band 7 observations optimal for resolving counterparts to the Herschel sources. With ALMA, we will (1) identify optical counterparts and resolve the multiplicity of our Herschel 250micron-selected sample in its 18 arcsec beamsize, (2) directly measure dust temperature and mass, and (3) characterize the dust as a function of star formation properties. Our unbiased dust temperature sample includes star-forming galaxies with warmer dust which have not yet been studied with ALMA at these redshifts. The proposed observations will open a new window to improve our view of dusty galaxy evolution in the early universe and test evolutionary connections to other galaxy populations such as local ULIRGs. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2017-12-06T09:19:35.000 |
| 4178 | 2018.1.00921.S | 256 | Exploring the link between [CI] and PAHs in star-forming galaxies | Recent work by our group has established a tight linear correlation between the emission from PAHs and CO in star forming galaxies (SFGs) at all redshift probed so far. Although these results suggest that PAHs can be used as an alternative proxy for the cold gas reservoir in SFGs, further cross validation with additional gas tracers is required. A promising candidate is the atomic carbon [CI]. However, [CI] observations of galaxies in the local universe are predominantly restricted to star-bursting galaxies (SBs) of which only a handful also have measured PAHs. We propose [CI](1-0) observations of 12 intermediate redshift ( = 0.16) SFGs with moderate infrared luminosities (derived from Herschel imaging) and robust PAH emission measurements (through Spitzer IRS) aiming to: 1) investigate the emerging trend between [CI] and PAH luminosity observed in local SBs and 2) derive molecular gas mass estimates and perform valuable comparisons and cross calibrations between three gas mass tracers (PAHs, [CI] and dust continuum). Moreover, we will complement existing [CI] observations of local SBs and high-z SFGs with a population of typical low-z SFGs that has been poorly sampled so far. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2022-08-30T17:48:30.000 |
| 4179 | 2016.1.00150.S | 8 | Resolving the AGN circumnuclear region with submillimeter water masers using the long-baseline ALMA | Extragalactic water masers at 22 GHz are well-known probes of circumnuclear gases in active galactic nuclei (AGN). Whereas 22 GHz water masers are inverted over a wide range of physical conditions (e.g., kinetic temperatures of Tk=200-2000 K; n(H2)=10^8-10^10 cm-3), it is believed that submillimeter masers are even more strongly inverted under more restricted physical conditions (Tk > 1000 K), suggesting that the submillimeter masers are a promising tracer of regions that cannot be probed by the 22 GHz masers. We have detected 321 GHz water masers toward the Circinus galaxy and NGC 4945 in Cycle-0 ALMA observations, with the masers being unresolved on these shorter baselines. To explore the innermost circumnuclear region of AGN using masers, we propose the first direct imaging with ALMA's longest 3.7 km baselines (band-7) of the submillimeter megamasers toward the two nearby AGN, both of which host a Type 2 Seyfert nucleus. At the requested 60 mas angular resolution that yields 3 mas positional accuracy, corresponding to 0.15 pc (assuming D=10 Mpc) with an SNR of 10 detection, it may allow the angular distribution of the submillimeter maser spots to be revealed. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-02-11T04:15:26.000 |
| 4180 | 2016.1.00819.T | 45 | Gamma-ray Burst Physics with ALMA: Direct Implications for the Explosions and Progenitors | Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, and thus serve as unique laboratories for high-energy astrophysics and compact-object formation, as well as premier probes of the high-redshift universe. Observations of GRB "afterglows" can provide critical insight into the energy scale and local environment of the bursts, thereby shedding light on the explosion mechanism and nature of the progenitors. However, the existing extensive optical/X-ray afterglow data are degenerate with respect to these GRB properties. Millimeter and centimeter observations are critical for breaking these degeneracies, but pre-ALMA GRB follow-up has yielded a detection rate of <5%. With the advent of ALMA and the Jansky VLA we anticipate a renaissance in GRB studies, and here we request the first set of ALMA ToO observations of up to 5 GRBs (9.5 hours) to begin to address key unsolved questions. We will support the ALMA observations with our JVLA Large Program (218 hours), extensive optical follow-up (Gemini, Subaru, Magellan, MMT), and X-ray data (Swift, Chandra, XMM). To ensure a high detection rate we will only trigger ALMA observations for bursts first detected with the JVLA. | Gamma Ray Bursts (GRB) | Cosmology | 2018-01-10T01:26:24.000 |
| 4181 | 2015.1.01194.S | 11 | Understanding the L1448 outflow "bullets" | Outflow ``bullets'' are discrete emission peaks that appear at extremely high velocities (EHV) in the youngest Class 0 outflows. Discovered 25 years ago in L1448, their true nature still remains a mystery. They were originally interpreted as discrete ejections of material from the protostar (i.e., true molecular bullets), and later proposed to result from unresolved ambient bow shocks, but both alternatives present a number of problems. New high resolution PdBI observations of the IRAS 04166 outflow have led us to believe that the ``bullets'' represent internal shocks in the most collimated part of the protostellar outflow. Such an interpretation would not only explain a number of observational puzzles, but it will nicely unify the phenomenology of molecular outflows and optical jets. In order to test our hypothesis, we propose to carry out a detailed observation of the L1448 prototype, searching for a kinematical signature that we believe has not been seen before due to a lack of resolution and sensitivity | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-10-01T02:42:12.000 |
| 4182 | 2019.1.01848.S | 54 | Water and Organic Molecules in Yound Bursting Object | We propose to observe the transition lines of water and organic molecules at ALMA band 7 towards a protoplanetary disk around young bursting object, FU Ori. FU Ori type burst is thought to be important in terms of thermal history of materials in planetary systems, including our Solar system. The burst phenomena affect the location of water snowline, distribution of water-containing solid materials, and also composition of organic molecules in the disk. Our chemical reaction network calculations together with line radiative transfer calculations, based on the detailed physical model of the disk, suggests that the proposed H2O lines are suitable to locate the water snowline in the disk (Notsu et al. 2018). By analyzing the line profile under an assumption of Keplerian motion, we will be able to locate the snowline spectroscopically even without spatially resolving the line emitting region. Meanwhile, many complex organic molecular lines have been detected towards FU Ori type objects recently. Our proposed observations of complex organic molecules together with the H2O lines give us information on organic molecule formation around the water snowline. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2022-10-28T16:24:06.000 |
| 4183 | 2021.1.00508.S | 27 | Following the water trail to the planet forming zone | Water plays a crucial role in the formation of stars, planets and habitable worlds. However, despite its importance, the evolution from molecular cloud to planetary systems, and in particular its origin on Earth, is not fully understood. For example, observations of low-mass protostars and upper limits for circumstellar disks revealed water abundances much lower than expected from ice observations. Another unknown is whether the water that formed in molecular clouds gets inherited by planets or whether water is destroyed and re-formed during star and planet formation. A key element toward a better understanding of water's journey from cloud to planet that is still missing, is spatially resolved observations of water in a circumstellar disk. The young disk around the Class 0 protostar L1448-mm is the ideal candidate to provide this piece of the puzzle: water emission is expected out to 60-90 au (0.2-0.3") and low resolution (5.5") HDO emission has already been observed. We propose to observe H218O, HDO and D2O toward this source as this provides the strongest constraints on inheritance or processing along the interstellar water trail. | Low-mass star formation, Astrochemistry | ISM and star formation | 2022-12-12T11:08:47.000 |
| 4184 | 2022.1.00366.V | 0 | A sample of SMBHs at <100 Rg scales: accretion flows, jets, shadows: GMVA+ALMA imaging | The photon ring around the black hole in M87 (billions Msun, powerful one sided jet) has been imaged with the Event Horizon Telescope (EHT), and exciting results on SgrA* (millions Msun, no/weak jet) are in the pipeline. Here we request 19 hours of ALMA time to enable GMVA+ALMA imaging of 7 sources in order to complete 30 microarcsec 86 GHz imaging of all 16 black holes bright enough to be imaged at <100 gravitational radius resolution with the GMVA and EHT. Together with proposed and future EHT+ALMA observations, we will: (a) image the jet base, thus providing unique and crucial constraints to jet launching theory over a larger parameter space (mass, spin, accretion rate, jet orientation and power); (b) potentially resolve accretion flows and orbiting hotspots, providing unique constraints to accretion theory; and (c) identify SMBHs whose photon rings can be resolved using super-resolution techniques developed by the EHT collaboration, thus providing additional constraints to gravity theories. This proposal is thus a first step towards leveraging the transformational results coming from M87 and SgrA* to a multi-parametric sample of black holes. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 4185 | 2022.1.00281.S | 10 | NGC 7582: A case study for the dual effects of AGN feedback and bars on star formation activity | AGN outflows and galactic bars can have an impact on their host galaxy that is difficult to distinguish. NGC 7582 provides an ideal case study for separating out the various mechanisms that may act to either suppress or enhance the efficiency of star formation and the availability of gas throughout the galaxy. Recent MUSE observations reveal clumps of star formation along the leading edge of the bar and a 3 kpc long bi-conical ionized gas outflow, which may be collimated by a central circumnuclear starburst ring. Narrow band wide-field imaging from Magellan/MMTF shows clumps of star formation along the leading edge of each side of the bar and throughout the center of the galaxy. We propose to map NGC 7582 in CO (2-1) observations over a large 3x1 arcminute map at spatial resolution comparable to the MUSE observations. The wide-field high angular resolution observations will provide a spatially resolved map of where the star formation efficiency and gas fraction are enhanced or suppressed relative to both the bar and outflow edges, to determine the relative effect of each mechanism, and the interplay between positive and negative feedback. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-02-10T19:10:52.000 |
| 4186 | 2018.1.01599.S | 58 | Do counter-rotating stellar discs promote black hole fuelling? | Accretion of external gas often produces stellar discs that counter rotate with respect to the main body of the galaxy. Numerical simulations predict that these counter-rotating discs will promote gas inflows to the central ~400pc of the galaxy, which may then fuel the black hole. We propose a pilot study to test this prediction. Using ALMA observations of CO(1-0) to trace the velocity and distribution of the cold molecular gas, we will determine if galaxies with counter-rotating discs show: 1) a higher molecular gas mass in their nuclei when compared with galaxies without counter-rotation; 2) dynamical evidence for gas inflow towards the black hole. If these two features are observed, it will indicate that external accretion events can provide the necessary conditions to fuel the black hole. Our pilot study will provide significant insight on how black hole activity has been triggered and fuelled for the past Gyr, an issue that remains unresolved in studies of black hole and galaxy evolution. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2020-08-20T17:42:36.000 |
| 4187 | 2015.1.00492.S | 2 | Magnetic field structure at the onset of high-mass star formation | It is strongly debated which physical processes dominate the initial fragmentation and collapse at the onset of star formation, and how much gravity, turbulence and/or magnetic fields contribute. While pre-ALMA magnetic field studies were limited to large spatial scales or low sensitivities, ALMA for the first time offers the opportunity to study weaker polarization signals during the earliest evolutionary stages at high spatial resolution. Therefore, we propose to investigate one well-studied infrared dark cloud (dark at 70 & 100mum) IRDC18310-4 where the turbulent properties are known from previous observations. These ALMA polarization data will reveal the magnetic field structure and strength in the plane of the sky, as well as its derivatives, i.e., the mass-to-flux-ratio and the turbulent to magnetic energy ratio. These parameters are crucial to characterize the stability and differentiate the importance between turbulence and magnetic field. We stress that this will be to the authors knowledge the first high-resolution magnetic field study at the onset of high-mass star formation and hence serve as a template for future more statistical studies of larger samples. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-11-22T00:00:00.000 |
| 4188 | 2013.1.00243.S | 6 | Spatially resolved AGN and starburst multi-phase outflows in the LIRG NGC 5135. Mapping the cold molecular phase | NGC 5135 is a nearby LIRG where there is evidence of extended (1-2 arcsec) muti-phase gas outflows associated with its Compton thick Seyfert 2 nucleus, and with several star-forming regions, located at ~3 arcsec from the nucleus and dominated by supernovae and young stars, respectively. Outflows in the coronal, ionized, partially-ionized, and warm molecular gas are already identified. We propose sub-arcsec (0.3 arcsec) CO(2-1) ALMA mapping of the extended and massive (> 5-50 x 10^6 Msun per region as derived from the outflowing warm H2 mass) cold molecular gas outflows, will derive their 2D structure (collimation, kinematics, mass) on scales of 100 parsecs. Gauging the contribution of the AGN versus that of the starbursts as the drivers of the outflow/feedback in U/LIRGs is difficult, and NGC 5135 is an ideal target for this kind of study. When combined with our already existing near-IR sub-arcsec VLT/SINFONI spectroscopy, a full picture of the multi-phase AGN-, supernovae- and stellar-driven outflows on the same galaxy will become available. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2016-08-22T12:23:55.000 |
| 4189 | 2016.1.01488.S | 22 | Dwarf disks and orbital motions in the triple XZ Tau system | Using ALMA data at 2.9 and 1.3 mm of the LBC SV program centered on HL Tau we studied the nearby XZ Tau triple system of young stars. From our study at 1.3 mm we concluded that XZ Tau B is surrounded by a dwarf transitional disk of dust with a radius of only 3.4 au and an inner cavity of radius 1.3 au (Osorio et al. 2016). This is the smaller disk ever imaged and its expected rapid evolution can provide important clues to study in real time the planet formation process. We confirmed the presence of a third component in the system (XZ Tau C), very close to XZ Tau A, and observed its fast orbital motion relative to XZ Tau A (Carrasco-Gonzalez et al. 2016) that appears to be related with the optical outbursts previously observed in HST images. From the CO(1-0) data, we imaged the molecular outflow at small scales tracing its origin close to the A/C pair (Zapata et al. 2015). Our results are based on data 24" away from the phase center, where the sensitivity has decreased by a factor of ~20 at 1.3 mm. We are requesting new band 6 ALMA data centered XZ Tau to go beyond our initial conclusions with data of much higher sensitivity, which can be obtained with a very short observing time. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2018-04-03T00:00:00.000 |
| 4190 | 2012.1.00306.S | 9 | Massive molecular outflows and negative feedback in active galaxies | We have recently found unambiguous evidence for massive molecular outflows in the Herschel-PACS OH spectra of a large number of nearby active galaxies. These outflows may represent the long sought evidence for the strong QSO mode feedback onto the host galaxy required by galaxy evolution models. Here we propose to use ALMA to study the same molecular outflows in 4 of our best Herschel targets by detecting and resolving the associated broad wings in CO(1-0). These observations will provide the necessary information on the geometry and size of the outflows to calibrate and test the assumptions made in the modeling of the Herschel OH spectra, which are of low spatial resolution. Combined, these data will allow us to determine the outflow rate and kinetic energy of these massive molecular winds and to derive the dominant mechanism driving them. They will also be extremely useful for the interpretation of future ALMA OH observations in the high redshift Universe. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2016-08-18T11:50:08.000 |
| 4191 | 2019.1.00904.T | 24 | Revealing the mass-loss process of flash-spectroscopy supernova progenitors | One of the key processes that determines the attributes of a massive stars, before they explode as supernovae (SNe), is mass-loss. Radio observations of SNe provide diagnostics of the CSM deposited by the SN progenitors. Thus early observations allow us to study the most recent mass-loss history of SN progenitor stars, during the final stages of their stellar evolution. The intermediate Palomar Transient Factory (iPTF) with its unique capability of discovering SNe less than a day after explosion, has recently made a groundbreaking discovery of flash spectroscopy SNe. The progenitor star of these type of SNe is belived to undergo a brief but large mass-loss episode, leaving a dense but thin CSM shell in its close proximity. When the star explodes, the SN ejecta is expected to interact with this shell. This interaction, however, is expected to last only for a few days and produce faint mm-wave emission that only ALMA can detect. Here we propose early ALMA observations of flash spectroscopy SNe. The proposed ALMA observations will provide measurements of the thin CSM shell density and its extent. In turn, these measurements will reveal what are the mass-loss processes that take place. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2022-08-12T22:36:20.000 |
| 4192 | 2018.1.01623.S | 97 | Tracing Gas Dissipation in the Transition Stage | The lifetime of primordial gas in circumstellar disks is a fundamental quantity that underpins our understanding of planet formation processes. The uncertainties involved in relating conventional gas tracers, including dust and CO, to the total disk mass increase significantly as the disk evolves. We propose a novel approach using nitrogen-bearing species, specifically N2H+, to track primordial molecular hydrogen gas. The low levels of available nitrogen incorporated into solid solar-system bodies relative to carbon suggest that nitrogen remains present in the gas over longer timescales. Elevated N2H+/CO ratios of two Upper Sco disks observed in ALMA Cycle 3 (2015.1.01199.S) support this hypothesis. Here we propose further investigation of the N2/CO ratio at different stages of disk evolution through observations of four mature disks in Upper Sco (5-11 Myr in age). Combined with previous observations we will have measurements of N2H+, HCO+, and CO in disks of similar mass that display over an order of magnitude difference in CO flux. This will provide crucial data regarding the primordial gas content of these evolved systems that only the superb sensitivity of ALMA can provide. | Disks around low-mass stars | Disks and planet formation | 2020-01-05T22:38:36.000 |
| 4193 | 2018.1.01755.S | 21 | Probing an Inner Disk at the Jupiter Orbital Radius around DM Tau | In ALMA cycle 5 observations (2017.1.01460.S), we discovered the Solar-system-scale inner disk at r=4 AU around DM Tau (d =140 pc). However, due to large beam size of about 6 AU in our observations, the inner disk was marginally resolved as two blobs. To spatially resolve the inner disk in cycle 6 observations, we propose band 6 dust continuum observations with the higher spatial resolution of about 20 mas. Since our cycle 5 observations indicated that the inner disk could be asymmetric and eccentric, we aim to confirm whether the DM Tau's inner disk really exhibits such structures in cycle 6 observations. Intriguingly, a candidate massive planet with a mass of 3 Mjup at r =6 AU around DM Tau was recently reported by Keck observations. Therefore, our proposed observations could indicate that the presence of massive planets at r= several AU both influences the geometry of the inner disk and plays an important role in planet formation at the Solar-system-scale region at several AU. There have been only few disks that are clearly resolved down to about 4 AU scale; thus, DM Tau plays an important role in understanding the planet formation at Solar system scale. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2020-10-18T15:14:45.000 |
| 4194 | 2015.1.01599.S | 3 | Remote Detection of Organics in Enceladus' Plume | Enceladus, one of Saturn's major moons, is the source of a spectacular water plume. This plume provides a unique possibility to trace the composition of an underground water reservoir in the outer Solar System remotely. Excitingly, Cassini has measured high abundances of small organic molecules such as HCN and H$_2$CO in the plume, suggestive of a rich underwater organic chemistry. More detailed and confident characterization of the plume by Cassini will be difficult, however, due to a lack of planned flybys after September 2015, insufficient instrumentation to quantify the organic composition, and a persistent worry that some of the organics Cassini is `measuring' may be residual from Titan flybys. We propose to use ALMA to obtain an independent data set securing the existence of the most detectable plume organic, HCN, allowing us to quantify its abundance relative to water and from there assess whether the HCN/H$_2$O abundance seems cometary or the result of an evolving, planetary chemistry. | Solar system - Planetary atmospheres | Solar system | 2017-10-20T23:31:02.000 |
| 4195 | 2017.1.00466.S | 164 | ALMA survey of lambda Orionis disks: understanding the influence of OB stars on planet formation | ALMA surveys of star-forming regions with ages spanning the protoplanetary disk lifetime (1-10 Myr) are providing new observational constraints on disk evolution and planet formation theories. Our recent survey of the middle-aged (3-5 Myr) sigma Orionis cluster showed clear evidence of disk evolution when compared to younger (1-3 Myr) and older (5-10 Myr) low-mass star-forming regions, but also reduced disk masses due to external photoevaporation driven by the central O9V star. Here we propose to survey the ~5 Myr old lambda Orionxis cluster, as it is a uniquely ideal target for studying the influence of massive OB stars on planet formation in nearby disks. Namely, its evolved age and lack of intra-cluster material should enhance the effects of external photoevaporation, and a recent supernova in the region may have further accelerated gas depletion. Studying these effects is important because many planetary systems, including our solar system, are likely born in clusters hosting OB stars; enhanced depletion of disk dust and gas should influence the types of planets that can form, thus our findings may help to explain trends seen in the exoplanet population. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2019-11-19T18:22:11.000 |
| 4196 | 2023.1.00429.S | 0 | Revealing the co-evolution of galaxies and the cosmic web in z = 2 protoclusters | Protoclusters are the densest environments at z ~ 2 and represent a unique setting to learn about the physics of the galaxy/cosmic web co-evolution during the peak of cosmic star formation. Our empirical picture of gas flows in and out of these enigmatic systems is essentially blank, because traditional diagnostics from the local Universe, such as the difference in gas metallicity with respect to the field, have yielded inconclusive results. To solve this problem, we will perform a novel experiment: quantifying the gas flows to and from protocluster galaxies via their location in the gas fraction-metallicity-stellar mass space. This project is enabled by 36.3 hr of ALMA Band 6 continuum observations of 64 galaxies within three z ~ 2 protoclusters in the well-studied COSMOS field, spanning a factor of ~100 in both stellar mass and star formation rate. Combined with metallicities, stellar masses, and star formation rates from archival near-IR spectroscopy, and rigorous comparison to hydrodynamic simulations and analytic models, our new ALMA data will provide critical insight on how gas is flowing between the cosmic web and galaxies during a key epoch of large-scale structure growth. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2025-05-16T13:49:50.000 |
| 4197 | 2024.1.00917.S | 0 | A Sub-kpc View of Star Formation Regulation Across Local Starbursting Disks | There is a broad consensus that feedback is a necessary component of any modern theory of galaxy evolution, and that galactic winds are needed to remove gas from a galaxy and thus regulate mass growth. However, there is an extreme lack in observations of molecular outflows, which is the main mass component of the wind. This suggests the true mass loss of winds, which is widely considered a critical part of any galaxy evolution model, remains poorly constrained by observations. We seek CO(2-1) observations in a sample of starbursting disk galaxies selected from the DUVET-Keck program to measure resolved outflows in molecular gas. The proposed galaxies have over 200 resolved ionized outflows confirmed with Keck KCWI. These observations are designed to (1) measure the main mass component of outflows (molecular gas) on kpc scales and track how outflow properties vary with changing SFR surface density; and (2) constrain the stellar feedback strength in the pressure-regulated, feedback-modulated framework of star formation, which is also found to change on kpc scales. This program will result in a statistically powerful sample of local multi-phase, starburst-driven outflows. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2025-10-24T13:37:53.000 |
| 4198 | 2017.1.01043.S | 24 | Probing Planet-Disk Interactions in the Fomalhaut System | The Fomalhaut system hosts both an iconic, eccentric debris disk and a hotly debated directly imaged companion, Fomalhaut b, whose orbit may pass through the disk in the future. The proximity of this system (7.7 pc) makes it a unique target to characterize dynamical interactions between a debris disk and its underlying planetary system at high spatial resolution. We propose high resolution Cycle 5 ALMA observations targeted at the pericenter and apocenter sides of the Fomalhaut debris disk to explore the nature of planet-disk interactions in the system. These new observations will allow us to (1) resolve azimuthal width variations, which will determine whether the disk is being shaped through secular perturbations by a planet, (2) identify any additional small-scale substructure in the disk, and (3) constrain whether the proposed planet, Fomalhaut b, is truly a planet or instead a dust cloud. | Debris disks | Disks and planet formation | 2019-10-22T16:37:24.000 |
| 4199 | 2022.1.01259.S | 0 | How common are streamers? An unbiased survey of all protostellar envelopes in a star-forming region | Streamers are asymmetric, narrow, and infalling lanes of material that can feed significant mass to protostellar disks from their surrounding environments. Streamers have been predicted theoretically, and observational work has shown that envelopes (the dense material outside of protostellar disks) are indeed asymmetric, yet streamers have only begun to be observationally characterized in detail in the last three years. This is because the streamers that have been recently identified were found serendipitously through a variety of molecular tracers in datasets originally meant to target other properties of protostellar disks and envelopes. Hence, these streamers are scattered through various star-forming regions and we do not know how common streamers are, although the frequency at which they are accidentally found is a hint that they may be a critical component of the mass accretion process. We propose to do an unbiased survey of all envelopes surrounding Class 0 and I protostars in a star-forming region to determine how common streamers are. We will build on targets already observed with archival ALMA data to efficiently achieve our goal (4.21 hr of new observations). | Low-mass star formation | ISM and star formation | 2025-08-24T00:51:56.000 |
| 4200 | 2018.1.01739.S | 81 | Out of gas? Characterizing the link between gas depletion and quenching in massive quiescent galaxies at z~1.5 | We propose to measure the CO 2-1 molecular gas reservoir of 6 massive, quenched galaxies at z>1. The proposed observations represent the first constraint on the distribution of cold gas in quiescent galaxies at the peak quenching epoch of the universe. We will measure the CO gas fraction, depletion time and star formation efficiency, measurements that are critical to constraining theoretical quenching models. Combining the measured star formation rate with the compact sizes of early quenched galaxies will prove a strong test of dynamically regulated star formation models, which seem to explain residual molecular gas in local elliptical galaxies. Finally, if the star formation efficiencies are indeed low, this would lessen the need for strong feedback models to produce galaxy bimodality in cosmological simulations. | Galaxy structure & evolution | Galaxy evolution | 2020-02-11T21:25:09.000 |
| 4201 | 2015.1.00584.S | 11 | First detection of high speed molecular gas in a quasar at the EoR | We propose to obtain the first detection of high speed molecular gas in a quasar located at the end of the Epoch of Reionization, by targeting CO(6-5) emission line in the z=6.0025 QSO SDSS J231038+185519. Molecular gas with velocity exceeding +-500 km/s with respect to the systemic one is often found in local AGN, tracing powerful outflows that are thought to regulate star formation in the host galaxies. No constraint is however available at z>4, thus little is known on the role of AGN feedback in the first quasars. J231038+185519 is the best target to provide the first constraint on AGN-driven molecular outflows at early epochs, because it is the mm-brightest QSO visible from ALMA at z>6, and likely is an AGN in a early evolutionary phase, where strong outflows are predicted. Based on [CII] data we expect that the CO emission occurs within the inner 0.6" from the nucleus. The main goal of this project is to map CO(6-5) emission line with angular resolution of 0.32" (=1.7 kpc rest frame), detect and model molecular disk rotation, search for fast outflows, accurately constrain the dynamical mass, and test whether CO is more compact than [CII]. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2018-03-08T14:57:55.000 |
| 4202 | 2021.1.00847.S | 5 | Directly measuring black hole mass of a quenched galaxy at z=2.1 | The recent discovery of massive, quenched galaxies in the early universe has changed our understanding of galaxy formation and evolution. The primary physical mechanism that is responsible for star formation quenching in such massive systems is yet to be identified. One of the most plausible mechanisms is by strong feedback from accreting supermassive black holes (SMBHs). The causality is still unclear due to the lack of direct evidence of SMBHs in the quenched system. To provide the smoking-gun evidence, here we propose Band 6 observations targeting a quenched galaxy at z=2.1. An unprecedented spatial resolution of ~75pc will be achieved by combining its strong lens-magnification and the resolving power of ALMA. Our observations aim to resolve the sphere-of-influence of the target, allowing us to directly measure black hole mass via the [CI] line. This will be the first measurement of black hole mass in a quenched galaxy beyond the local universe. | Early-type galaxies | Galaxy evolution | 2022-11-08T19:36:22.000 |
| 4203 | 2019.1.00205.S | 44 | Physical conditions and chemical processes of the ISM at high redshift: a line survey towards BR1202-0725 | Understanding the nature of the high-z galaxies requires a full view of the ISM by reaching the molecular complexity. However, only a few studies of gas tracers beyond CO have been performed so far at high-z due to the observational difficulties. All the high-z line surveys are exclusively in lensed systems which suffer from differential lensing. ALMA now offers opportunities to conduct spectral line surveys at high-z, even in the brightest unlensed galaxies. We propose to carry out a first such deep line survey mainly for the multi-transitions of dense gas tracers and CO isotopologues. Our target is a unique cluster of unlensed galaxies consisting of a submm-bright SMG-QSO pair and two Ly-a emitters at z=4.7. With four B3 tunings, we will be able to cover a total of ~150GHz in the rest frame and obtain spectra for all the four galaxies simultaneously, especially for the unique dusty star-forming QSO host. Using non-LTE and astrochemical models, we will be able to study in detail the physical conditions and chemical processes of the ISM, constraining the properties of the UV/cosmic-ray/X-ray fields, and gaining insight into the initial conditions of star formation (e.g., IMF). | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2021-02-26T22:10:35.000 |
| 4204 | 2023.1.01460.S | 0 | Quantifying the galaxy-scale impact of radio jets | Our aim is to investigate whether radio jets can affect the physical conditions of the ISM not only through jet-driven outflows, but also by more gentle interactions as the jet evolves, as suggested by simulations. These could affect the gas over long time scales which, in turn, would impact the long-term evolution of star formation in the host galaxy. We propose CO(2-1) and CO(3-2) observations to map line ratios tracing the conditions of the molecular gas in three radio AGN which are in different phases of evolution. Ratios deviating from typical of quiescent gas will be the signature of the AGN impact. The targets were selected from public data in the ALMA archive. Extended CO(1-0) emission is detected in all of them. Simulations predict the impact of an expanding jet to also extend perpendicular to the radio axis, affecting a large volume of the galaxy. The proposed observations will allow us to confirm this by relating the line ratios maps to the morphology of the radio emission. The targets are in different evolutionary phases and the observations will tell whether the impact of the jet changes character as the jet evolves, an important test of predictions of simulations. | Outflows, jets, feedback | Active galaxies | 2025-09-30T17:59:22.000 |
| 4205 | 2019.1.00696.S | 9 | The Shape of Things to Come: Planetary Influence on the Inner Edge of the Closest Debris Disc | Epsilon Eridani is the 3rd nearest Sun-like star to our Sun and the nearest one known to host a debris disc. This proximity makes it a prime system for understanding dynamical interactions between planets and a disc. In cycle 2 we observed the northern part of its debris ring and resolved the width of the ring for the first time, finding it to be just 13 AU wide. Based on the narrowness of the ring, we proposed that a planet of around 0.4 Jupiter masses is likely located at 48 AU. We also noticed low level emission just interior to the main belt that could either be described by a steeply rising inner edge of the belt or an extra component just interior to the main belt. In order to determine more precise parameters of this planet and understand how it is interacting with the ring, we propose to image the entire ring with 6 pointings in order to determine the shape of the inner edge of the ring and use this to predict the mass and location of the outermost planet in the system. By observing the whole ring, these observations will also allow us to constrain the eccentricity of the ring, which can in turn constrain the eccentricity of the outermost planet. | Debris disks, Exo-planets | Disks and planet formation | 2021-07-06T15:40:34.000 |
| 4206 | 2012.1.01020.S | 2 | Submillimeter deep imaging of the highest redshift SMG candidate in the Subaru Deep Field | Submillimeter galaxies (SMGs) are thought to play important roles in formation of giant elliptical galaxies. Despite its huge infrared luminosity and star formation rate, the redshift distribution of SMGs has been still in mystery. Recent studies have revealed ‘high-z’ tail at z > 3, but no SMG at z > 5.3 has been reported thus far. When did the ‘first’ SMGs occur in the early universe? We propose continuum imaging at λ = 1100-μm, 880 μm and 450 μm toward a highest redshift SMG candidate, SDF1100.001 discovered in the AzTEC/ASTE 1100 μm SMG survey in the Subaru Deep Field. We aim to estimate photometric redshft free from dust extinction using multi-wavelength submillimeter photometric data toward SDF1100.001. SDF1100.001 has two plausible IRAC counterpart candidates at z ~ 6 with Mstellar ~ 10^11 M⊙. It is worth mentioning that both of the plausible counterparts at z ~ 6 are extremely faint in Subaru deep K′-band image (2.2 μm; 2 σ sensitivity of 26.2 mAB ), one is dropped out and the other is 25.5 mAB. These results suggest extremely dusty obscured objects at very high redshift. The proposed ALMA observations will therefore identify a major merger system at z ~ 6, which is veiled by extreme dust extinction and other existing instruments can not reveal. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2015-12-04T17:18:44.000 |
| 4207 | 2017.1.00028.S | 45 | Deuteration in galaxies: Breaking ground with ALMA | Since the detection of unexpectedly high deuterium fractionation in the Galactic Center almost 20 years ago, many follow up observations were carried out in different Galactic environments which showed deuterium abundances well above the elemental ratio D/H~1.5x10^-5. These observations have been well reproduced by chemical models and showed that deuteration may be an excellent tracer of the degree of chemical processing of the gas by star formation, and therefore a tracer of pristine material feeding the future star formation events. Though models have been proposed for different extragalactic environments, only now, with the superb sensitivity of ALMA, observations are possible. We thus propose to measure for the first time the D/H ratio in the starburst ISM of NGC 253. We aim at simultaneously observe DCN, DCO+ and N2D+, as well as a second observation to target the 13C substitutions of HCN, HCO+ as well as N2H+. | Starbursts, star formation, Galaxy chemistry | Active galaxies | 2019-09-14T16:20:00.000 |
| 4208 | 2022.1.01536.S | 20 | Long-lasting chemical changes in response of the current eruption of the young pre-main sequence star EX Lup | The spectacular luminosity outbursts of the EX Lupi-type (EXor) pre-main sequence objects are driven by a 10-100x rise of the accretion rate from the circumstellar disk onto the star. The eruptions affect the properties of the inner disk via the enhanced radiation field, an essential process to be considered in the inner disk evolution and initial conditions for terrestrial planets. In 2022 February EX Lupi, the prototype of EXors, started a new large outburst. Fortunetelly, ALMA could take a chemical snapshot during the rising phase. Our detailed chemical modelling predicts a dramatic increase of molecular abundances during the eruption, and that the abundances of some species may stay high for longer periods. To test it, we propose ALMA observations of EX Lup in the post-burst phase. We will request an 9.6h single epoch observation in Band 6 and 7 with a resolution of 0.2. Analysing together with the outburst ALMA data, our post-burst observations will enable a chemical evolutionary study of an EXor outburst. We will check if outbursts produce or destroy certain key molecules in the disk, and answer if the chemical changes last long enough to imprint forming planets. | Low-mass star formation | ISM and star formation | 2024-07-21T03:55:37.000 |
| 4209 | 2016.1.01051.S | 2 | Methanol Maser Polarization in Massive Star Forming Regions | Methanol masers provide unique information of very small and dense regions embedded in thick dust envelopes, but their polarization observations have been rare, partially because they were thought to be dominated by turbulence. Recently some polarization observations of the Class II methanol masers near the central object present evidences that the fields traced by masers are aligned and associated with the overall field morphologies of star forming cores, but not much is known for Class I methanol masers, which is known to trace regions shocked by outflows. We propose for the line polarimetric observation in one of the strongest Class I methanol maser 95GHz transition toward two star forming regions that are bright and have high fraction of linear polarization in the single-dish observations. This observation will help us to understand if the magnetic field morphology of the Class I methanol maser are randomly distributed or ordered like the Class II masers. | High-mass star formation | ISM and star formation | 2018-07-27T22:36:52.000 |
| 4210 | 2019.1.01059.S | 3 | Oph IRS 48: an Ideal Target for Differentiating Disk Polarization From Dust Scattering and Radiatively Aligned Grains | Identifying the dominant mechanism responsible for polarizations in protoplanetary disks is important for interpreting both existing and future polarization data. There are three mechanisms discussed in the literature: scattering, magnetic alignment, and radiative alignment. The last one is a newly proposed mechanism that relies on the anisotropy in the radiation field, similar to the scattering-induced polarization. A key difference is that scattering-induced polarization relies on the anisotropy in the radiation field at the same (sub)millimeter wavelength as observed, whereas radiative alignment relies on the anisotropy in the radiation field near the peak of the SED, which is typically at a much shorter wavelength. The disk of Oph IRS 48, with its prominent "kidney-shaped" dust trap, has different radiation fields at (sub)millimeter wavelengths and the (shorter) wavelengths responsible for radiative grain alignment. It is thus an ideal target for distinguishing these two competing mechanisms. We make predictions for the polarization patterns expected from different mechanisms and propose to test these predictions with ALMA Band 7 polarization observations at 0.089". | Disks around low-mass stars | Disks and planet formation | 2022-11-15T00:57:14.000 |
| 4211 | 2022.A.00036.S | 249 | Band 3 Survey of HL Tau as a WSU Test Dataset | We propose a Band-3 survey of the protoplanetary disk HL Tau, with the goal of roughly emulating the properties of a future WSU project that takes full advantage of the upgraded correlated bandwidth, IF range, and spectral resolution. The proposed dataset will allow for multiple pathfinder stress tests of both calibration and imaging, which will provide value across multiple subsystems / WSU working groups and inform future (potentially much more expensive) observations for WSU test datasets (recommended in the DPDA working group memo). The full survey, as approved, comprises 32 Science Goals. For practical reasons the initial project file has 23 of the SGs; the remaining 9 SGs will be added during Phase 2 | Disks around low-mass stars | Disks and planet formation | 2024-03-28T11:17:39.000 |
| 4212 | 2015.1.00066.S | 68 | Looking into ``invisible" ISM: Physics and chemistry of Galactic molecular absorption systems under PDR-like environments | In the Galaxy, the detailed nature of ``invisible" diffuse medium that is too cold to be observed in emission is shrouded in mystery, and the unique way to investigate such medium is the observation of its molecular absorption toward bright radio-loud quasars. Here we propose the Band 6 observation of the upper transitions of C2H, SiO, H13CO+, HCO, H13CN, CS and c-C3H2 in four Galactic molecular absorption systems, which have already been observed in the lower transitions, and three of which are reported to be under PDR-like environments. With the high sensitivity and velocity resolution of ALMA, we will be able to conduct multi-transition study of absorption lines of the seven species in diffuse medium, and to determine or tightly constrain the excitation temperatures of them for the first time, even in a few hours' observation. This leads us to verify whether PDR-like diffuse medium is in equilibrium with the CMB or not, and to estimate the column densities of various molecules with a high accuracy, as well as to get new insight into understanding the physics and chemistry of such ``invisible" medium. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2017-06-27T06:51:28.000 |
| 4213 | 2015.1.00722.S | 14 | Blowin' in the Wind: The Outflows of DG Tau | The environment of Young Stellar Objects is shaped by various types of jets, outflows and winds. Not only are their launching and acceleration mechanisms only poorly understood, but their mutual interactions and in particular their effects on envelope and disk dispersal defies full explanations. While molecular outflows from embedded protostars may be driven by wide-angle winds entraining surrounding envelope material, such mechanisms are questionable for optically revealed T Tauri stars (TTS). Yet, an expanding CO-line emitting structure is found around the disk of the active TTS DG Tau, suggested to be the result of disk erosion by a wide-angle wind. Other features in this environment include a cone of H2 line emitting material above the disk which may be related to a wind as well. Lastly, a prominent jet is ejected which does not fill the H2 cone. Sensitive high-resolution ALMA observations in the CO(2-1) 220 GHz line will for the first time give an overview of the molecular wind/jet/outflow inventory of a TTS and provide insight into interactions between winds, outflows, and the eroding disk. ALMA data will complement a wealth of data already obtained at other wavelengths. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-03-23T19:10:14.000 |
| 4214 | 2017.1.00370.S | 65 | Confirmation of Interstellar Hydroxylamine (NH2OH) | The search for interstellar hydroxylamine (NH2OH), a putative glycine precursor, has garnered much attention in recent years, producing several observational, modeling, and laboratory studies. While originally predicted by models to be highly-abundant in hot core regions, observational studies failed to identify NH2OH in a variety of molecularly-rich sources. This has lead to the idea that the overall abundances of hydroxylamine may be smaller than expected because of rapid destruction pathways, such as dissociation by UV irradiation. Recently, however, we conducted an ALMA survey towards source NGC 6334 I, and we were able to tentatively assign four transitions to NH2OH. This may be the first detection of this important molecule, but needs confirmation in a follow-up study. Because NH2OH is so light, even at 125-175 K the strongest transitions span the full ALMA frequency range. Here, we propose follow-up observations of the source across ALMA bands to confirm this important detection. | Astrochemistry | ISM and star formation | 2020-01-24T03:23:15.000 |
| 4215 | 2016.1.00226.S | 75 | A comprehensive study of the interstellar medium 830 Myr after the Big Bang | We propose a comprehensive study of the physics of the interstellar medium in a luminous QSO recently discovered by our group at z=6.4, i.e., 830 Myr after the Big Bang. This study is motivated by a strong [CII] line detection that allows us to predict relatively strong line emission for 13 molecular and 4 fine-structure lines that, fortuitously at this redshift, are observable with ALMA. With only 6 frequency settings, we will target 17 lines tracing the ionized, neutral, and molecular gas in this star-forming galaxy. Including the already secured very bright [CII] line, these observations will constrain key physical properties of the gas at the dawn of galaxy formation, such as density, temparature, metallicity, ionization degree, and hardness of the radiation field. The selected bright QSO at z=6.4 therefore provides us with a unique opportunity to investigate the physics of the interstellar medium at the formation of todays massive quiescent galaxies. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2018-12-23T00:00:00.000 |
| 4216 | 2011.0.00059.S | 0 | GG Tau: the Ringworld revisited by ALMA | Studying planet formation in the context of multiple stellar systems is fundamental because a large fraction of the stars form in multiple systems. However, there are only a few PMS (Pre-Main-Sequence) binaries which allow detailed analysis of the dynamical and physical properties of their circumstellar and circumbinary material. Thanks to its distance (140 pc), and brightness (800 mJy at 1.3mm), the spectacular "Ring World" circumbinary ring around GG Tau A (a 0.25" separation binary system of two TTauri stars of 0.6 solar masses) provides a unique opportunity for a multi-wavelength, spatially resolved study of the physics of mass accretion onto a central binary (e.g., through cool gas/dust detected at mm wavelengths, dust distributions from optical/IR scattered light, and near IR tracers of warm gas). We propose to use the unique sensitivity and resolving power of ALMA to obtain continuum and line images of the GG Tau A young binary star and circumbinary disk system in order to test, for the very first time, theories of accretion onto the host stars. Using Band 9 and the extended configuration, we would like to observe the system in continuum and in CO J=6-5 simultaneously. Our imaging simulations show that the outer ring and the streaming material will be observable in a single primary beam. Only ALMA, even in cycle 0, can achieve such a project. The spectacular images at resolution at 3-4 times better than now available and unprecedented sensitivity will enable significant advances in astronomical study of the evolution of young binaries and the dynamic sculpting of their disks. | Disks around low-mass stars, Low-mass star formation | Disks and planet formation | 2014-08-12T13:49:50.000 |
| 4217 | 2022.1.00226.S | 47 | Isotopic tracers of the evolution of early-type galaxies | We propose 12CO, 13CO, and C18O (1-0) and (2-1) observations of 10 nearby early-type (elliptical and lenticular) galaxies, including 5 field galaxies and 5 Virgo Cluster members. We will use non-LTE radiative transfer modeling to infer the physical properties, optical depths and isotopic abundance ratios in the molecular gas. Previous work has noted significant differences in 12CO/13CO between field and cluster early-type galaxies, and it is hypothesized that either the two populations have different nucleosynthetic enrichment histories, or that ram pressure stripping is removing low-density molecular gas in the cluster galaxies. Early-type galaxies are particularly important for studies of ram pressure stripping because they have been in the cluster longer than spirals and have suffered more stripping than spirals -- so the work we propose here will extend beyond studies on spirals (like the VERTICO project). C18O abundance measurements in early-type galaxies will also contribute to larger-scale projects on constraining the production mechanism of 18O and its possible use as an indicator of the initial mass function. | Early-type galaxies, Galaxy chemistry | Galaxy evolution | 2024-02-08T21:50:08.000 |
| 4218 | 2019.1.01155.S | 9 | Extending the GEMS sample of brightest gravitational lenses | Strong lensing has many applications, but the number of known examples is still small and more are needed - particularly for probing the statistics of halo substructure to constrain dark matter properties. Some of the submm-brightest lensed systems come from the Planck+Herschel-selected GEMS sample. In hindsight the selection process for this was too conservative, as well as deliberately favouring northern objects. We have found 15 additional Planck+Herschel-selected sources consistent with strong gravitational lensing, and we propose to confirm them using ALMA continuum imaging at 870 um. These observations will not only extend the number of known strong lenses significantly, but also allow us to begin studying their dark matter morphologies, eventually leading to much better contraints on the dark matter power spectrum on small scales than has been previously possible. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2021-03-05T20:32:37.000 |
| 4219 | 2018.1.01530.S | 86 | Probing the Excitation and the Mass-Luminosity Conversion Factor of the Dense, Star Forming Gas Across Galaxy Disks | We propose to observe the 3-2 line of the canonical, extragalactic dense gas tracers HCN and HCO+ with ACA in band 6 for 4 selected fields across 3 normal, star forming disk galaxies. The 4 fields cover a broad range of environmental conditions. The goal is to provide constraints on excitation and, more generally, the physical conditions in the dense, star forming gas across galactic disks. Such studies were previously largely the domain of Milky Way studies or focused on bright galaxy centers or (U)LIRGs. In combination with our previous IRAM 30m and ALMA campaigns mapping the ground transition of these molecules, these observations are key to link the spatial variations in: (1) the physical conditions of the dense, star forming gas; (2) the cloud properties measured from our cloud-scale ALMA CO observations at higher resolutions; (3) the environment the clouds live in. Further, HCN excitation via line ratios are essential to constrain the HCN conversion factor from which dense gas masses are derived. This will allow us to update scaling relations between dense gas and star formation and differentiate between competing models for how star formation is regulated across galaxies. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2020-08-21T13:22:24.000 |
| 4220 | 2018.1.00879.S | 68 | Detecting and Mapping cis-OSSO on Venus | The identity of the UV absorber on Venus is a longstanding mystery that has withstood decades of dedicated scientific investigation. A recent hypothesis for the unknown absorber is the dimer of SO [aka OSSO]. With ALMA, we can not only detect sub-mm lines from this absorber, but we can also probe the mechanism by which it forms at altitudes of 70-100 km. We propose to observe cis-OSSO in the Venus mesosphere, and characterize its variations with Venusian longitude, latitude, and hemisphere. Verifying an anticorrelation with SO is an important test of the proposed formation mechanism, and to investigate this we will observe Venus at half-illumination. Cycle 6 is the best time for this measurement given that we will have nearly simultaneous temperature measurements from the Akatsuki spacecraft. We target 10 cis-OSSO and 2 SO lines in Band 6, using the 12m array in conjunction with the ACA. After line stacking, we expect to achieve a S/N per beam of ~3. This measurement will constitute the first detection of OSSO on Venus, and if we can confirm an anticorrelation with SO, it will be very strong evidence that OSSO is the UV absorber that has eluded planetary scientists for 40 years. | Solar system - Planetary atmospheres | Solar system | 2020-01-16T00:00:00.000 |
| 4221 | 2012.1.00769.S | 0 | Serpens South: Outflows impacting the youngest, densest proto-cluster | In the earliest stages of star formation, molecular outflows from protostars entrain gas, inject energy and momentum into protostellar clusters and perhaps drive turbulence in a cloud. In a very young, dense cluster environment, the encounter probability of outflows with other forming protostars is high, so these outflows may affect subsequent star formation, as well as sculpt their nascent environment. We propose ALMA observations of the youngest, densest protostellar cluster Serpens South, located relatively nearby at 415 pc. With a resolution of 1.5 arcseconds (600 AU at 415 pc) and the sensitivity of ALMA, we will observe CO isotopologues with Band 6 in order to resolve individual outflows, identify their driving sources, and assess their impact on the surrounding cluster environment on physical scales of 0.003-0.3 pc. We will map a mosaic of 120x165 arcsec, within which 42 YSOs are known to reside. A remarkable 90 percent of these sources are Class 0 or I, young protostars which drive the most energetic outflows. This proposal is the critical component in a comprehensive study of outflow-cloud interaction, for both its sensitivity and resolution on scales very near to the driving sources of protostellar outflows within a dense cluster environment. | Outflows, jets and ionized winds | ISM and star formation | 2015-04-21T14:27:08.000 |
| 4222 | 2018.1.00633.S | 86 | [C I] observations toward gaseous debris disks with ACA | We propose a mini survey observation of the fine-structure line of atomic carbon ([C I]3P1-3P0; 492GHz) toward three gaseous debris disks candidates in Band 8 at an angular resolution of 2.6 arcsec. We recently succeeded in the first detection of the [C I] line toward the representative debris disks, 49 Ceti and Beta Pictoris, with the ASTE 10 m telescope, and found that the C/CO ratio is as high as 54±19 and 69±42, respectively (Higuchi et al. 2017; Cataldi et al. 2018 submitted). The C/CO ratio may be the best way to tell whether the gas is primordial (with a standard H2/CO ratio) or secondary (no H2 and mostly from icy grains). The high C/CO ratio supports a smaller abundance of H2 because the C to CO conversion reaction requires H2. The smaller abundance of H2 implies the gas has a secondary origin. Thus, the [C I] observation will provide us with a novel method to derive the gas to dust ratio (H2 mass/dust) in the debris disks. In this program, we extend this method to a larger sample with ALMA to understand the history of gas dissipation in the planetary system formation. | Debris disks | Disks and planet formation | 2020-11-01T06:58:14.000 |
| 4223 | 2022.1.00800.S | 16 | Accretion Instabilities in EC 53 | The variable mass accretion is the key process in the star formation, but it is still challenging to study observationally and to explain theoretically. The analysis of NEOWISE mid-IR light curves for the thousands of Gould Belt protostars shows that most Class 0/I sources showed the flux variability. Among them, EC53 is a young Class 0/I protostar showing quasi-periodic accretion with one of the highest amplitude flux variation. In addition, moderate (~0.1"-0.3") ALMA observations reveal that EC53 harbors a large and massive, potentially gravitationally unstable, disk and circumstantial evidence of infall from the envelope. These pieces of evidence combined lead to a picture of EC53 as unstable to accretion at multiple scales and thus an excellent laboratory to investigate the physical mechanisms responsible for the disk instabilities. We thus request (1) high angular resolution (0.015"; 6.5 au) continuum observations of the disk in Band 7 to hunt for spirals, rings, binarity, and/or clumping and (2) moderate 0.1" (40 au) resolution molecular line observations in Band 6 searching for evidence of shock-heated gas streaming from the envelope to the disk. | Disks around low-mass stars | Disks and planet formation | 2024-11-06T20:00:48.000 |
| 4224 | 2015.1.00964.S | 140 | The astrochemical evolution from disk formation to disk dissipation | The volatile compositions of planets, including water and organic reservoirs, are set by the ice and gas composition of protoplanetary disks. The disk volatile composition, including the elemental division between ice and gas, may change dramatically between the formation of disks in embedded protostars and the time of disk gas dispersal ~5Myrs later. Constraining this chemical evolution at different disk radii is key to predict the composition of planets and planetesimals forming at different disk locations and time scales. We propose to undertake the first systematic exploration of how the disk chemical composition evolves with time, from disk formation in protostars (<0.2Myr) to the oldest (5Myr) surviving protoplanetary disks. The proposed survey sample is drawn from interferometric gas and dust studies of nearby star forming regions of different ages (0.2-5+Myr). The targeted lines have been chosen to primarily probe how the levels of O, C and N sequestration into solids depend on disk evolutionary stage and radius, the key aspect of disk chemistry in the context of planet formation, but we will also cover tracers of H and N fractionation and other time-dependent chemistry. | Astrochemistry | ISM and star formation | 2017-08-21T05:58:03.000 |
| 4225 | 2017.1.00636.S | 29 | The first direct measurement of Saturn's stratospheric winds | In Saturn, zonal winds (Eastward winds) have been measured by tracking cloud motions up to the tropopause level. In the cloudless stratosphere, 200 km above cloud level, the winds have never been directly measured. In the extra-tropical stratosphere, thermal wind balance suggests that the zonal winds decay with altitude to power the meridional circulation. In contrast in the tropical region, thermal wind balance suggests that the zonal winds oscillate vertically and temporarily with large amplitude. However, this picture is uncertain as thermal wind balance does not hold at the equator and that the thermal structure is not fully vertically sampled around the tropopause. Hence, only a direct measurement of the zonal winds can confirm the actual wind regime in Saturn's stratosphere and set the global picture of general circulation in Saturn's stratosphere. Our ALMA measurement will constrain a General Circulation Model of Saturn we are now developing. | Solar system - Comets | Solar system | 2019-07-10T14:22:43.000 |
| 4226 | 2021.2.00164.S | 0 | Study of microquasar SS433 as a cosmic-ray particle accelerator | PeVatron, the accelerator of the galactic cosmic-ray particles having the energy above 10$^{15.5}$ eV, is still not specified. Galactic X-ray binary jet is a prime candidate of PeVatron. Recent TeV gamma-ray observation showed a clue that the jet of the X-ray binary SS433 would accelerate cosmic-ray protons to a higher energy than 10$^{15.5}$ eV. To verify it, we propose the observation of molecular clouds, which are possibly the origin of the TeV gamma-ray emission induced by high energy cosmic-ray protons. This study should bring an essential breakthrough to determine PeVatron in our galaxy. We plan to verify whether the molecular clouds can be identified around the TeV gamma-ray emission. After that, we investigated the detailed spatial and velocity structures of the clouds to reveal the relation between the SS433 jet and the clouds. Finnaly, we assess the molecular clouds can be the origin of the TeV gamma-ray emission based on the physical parameters of the clouds. We will observe $^{12}$CO(J=1-0) and $^{13}$CO(J=1-0) lines. The required total time is 42.31 hrs. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-06-18T22:04:41.000 |
| 4227 | 2017.1.01430.S | 52 | Measuring the mass distribution with unprecedented accuracy in the CLASH cluster MACSJ1206 | Multi-probe analyses are needed to achieve one of the main goals of precise and accurate cosmology: the unbiased cluster mass measurement at the per cent level. The combination of independent observables, from X-ray to lensing to Sunyaev-Zeldovich effect, guarantees that the measurement of mass and other intrinsic properties are unbiased and systematic-free. However, despite the growing interest, this topic is still in its infancy. We have started the CLUster Multi-Probes in Three Dimensions (CLUMP-3D) project (Sereno, Ettori et al. 2017) to get the unbiased intrinsic properties of galaxy clusters by exploiting rich datasets ranging from X-ray, to optical, to SZ wavelengths. As a pilot study to address this fundamental science case, we aim at completing the wavelength coverage over different scales of the galaxy cluster MACS~J1206.2-0847, for which the only missing piece in the puzzle is SZ at high angular resolution. | Galaxy Clusters | Cosmology | 2019-01-15T21:27:04.000 |
| 4228 | 2015.1.00072.S | 66 | Does the magnetic field regulate the collapse in the massive core G31.41+0.31? | The most clear example up to date of an hourglass-shaped magnetic field morphology in the high-mass regime is that of the very massive (>500 Msun) and luminous (2e5 Lsun) hot molecular core G31.41+0.31. To establish whether the magnetic field plays an important role in the collapse of G31.41+0.41, we propose to observe this object with ALMA in Band 6 with an angular resolution of 0.18 arcsec, which will provide an unprecedented image of the magnetic field morphology and kinematics down to about 1000 AU scales. | High-mass star formation | ISM and star formation | 2018-07-02T06:27:15.000 |
| 4229 | 2015.1.00725.S | 14 | Witnessing grain growth across the CO snowline in HD163296 | To grow and form planetesimals and, eventually, rocky cores of planets, dust grains in protoplanetary disks need to overcome several barriers. One intriguing theoretical idea is that sublimation fronts of the major volatiles in disks may promote a localised growth process. ALMA has started to resolve the CO snowline (one of the major snowlines in disks) in nearby disks and for the first time offers the possibility to directly test this theoretical scenario. Reanalizing the ALMA Band 7 Science Verification data we have recently discovere an excess continuum emission at the location of the CO snowline in the protoplanetary disk surrounding HD163296. We thus propose to obtain high sensitivity, 0.3arcsec resolution images of the disk at 90GHz and derive directly a measurement of the spectral index of the emission across the snowline. Our experiment is designed to conclusively prove whether grain growth is promoted at the location of the CO snowline and thus provide a critical test for the theoretical models of grain evolution in diesks on the path of forming planetary systems. | Disks around low-mass stars | Disks and planet formation | 2018-01-12T22:33:09.000 |
| 4230 | 2016.1.01046.S | 23 | Complex Organics in Solar Nebula Analogs | The ubiquity of complex organic molecules (COMs) in disks determines the typical pre-biotic potential of nascent planetary systems. Observations of protostellar cores and comets have long shown that disks are bookended by a wealth of chemical complexity. In disks, however, prevalent freeze-out of volatiles and small angular scales kept COMs hidden until the advent of ALMA. In separate C2 programs we detected CH3CN in the disk of V4046 Sgr and CH3OH in TW Hya, providing clear evidence for the presence of N and O-bearing COMs in these old, nearby Solar Nebula analogs. To provide first constraints on the relationship between N- and O-bearing COMs during planet formation we now request the complementary observations, i.e. CH3OH toward V4046 Sgr and CH3CN toward TW Hya. The two nearby, iconic disks have among the best constrained physical and chemical structures, making them optimal for both detecting and characterizing trace species. The resulting observations will provide a key first constraint on whether the ratios of different COM families are consistent across Solar Nebula analogs, and between such analogs and remnants of the Solar Nebula itself, i.e. comets. | Disks around low-mass stars | Disks and planet formation | 2018-02-28T04:26:27.000 |
| 4231 | 2022.1.00707.S | 12 | Confirming the presence of star formation in the most luminous quasars | The FIR continuum emission from quasar host galaxies is generally considered to be an indicator of the amount of their star formation with little contribution from dust heated by the quasar itself. Recently, it has been shown using ALMA that the most luminous quasars at z~2 have SFRs (based on rest-frame 285um luminosity) consistent with the star-forming galaxy population. However, there are claims, based on simulations, that AGNs can heat dust, even over galaxy-wide scales, above that produced by the torus, thus SFRs can be overestimated if based solely on the FIR luminosity. Here, we aim to test this by measuring whether the star formation is within dense molecular gas by mapping the CO (J=5-4) emission on galaxy-wide scales at high signal-to-noise for three of the most luminous quasars at z=2 with ALMA continuum measurements already available. Resolution of this issue has wide implications on AGN science with ALMA, particularly the role of quasar feedback in quenching star formation. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-06-08T20:23:34.000 |
| 4232 | 2021.1.00435.S | 42 | ASW2DF: Census of the Star-Formation Properties in a Protocluster at z=2.2 | One of the best studied high-z large scale structures so far is the protocluster associated with the HzRG MRC1138-262 at z=2.16, the so-called "Spiderweb" protocluster. We propose an ambitious, wide and deep ALMA 1.2mm mapping of a unique 3'x6' field (equivalently ~1.5 x 3.0 pMpc) within this overdense field. Our ALMA dust continuum imaging down to SFR=80Msun/yr will add the missing piece to our exquiste multi-wavelength coverage with a huge investment of telescope time (e.g. ESO VLT, Subaru). We expect to find ~80 ALMA sources based on the reported overdensity of LABOCA sources in this field. The major goal of this program is to study the impact of environment on galaxy formation and evolution. To achieve this goal, we aim to: 1) derive the reliable number counts for dusty galaxies in the protocluster environment without suffering from source confusion, 2) measure the star formation efficiency of protocluster member galaxies and test their environmental dependence. The requested contiguous ALMA 1.2mm mapping will complement the existing ATCA CO(1-0) data and the scheduled JWST GO cycle-1 Pa-beta imaging, both covering the same 3'x6' field. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-01-24T23:14:25.000 |
| 4233 | 2016.1.00668.S | 2 | Constraining the Properties of the Interstellar Medium of the Most Luminous Galaxy in the Universe | At a redshift of 4.601 and with a luminosity of Lbol = 3.5 x 10^14 Lsun, WISE J22460526 (W2246 hereafter) is the most luminous galaxy in the Universe detected to date. Cycle 2 ALMA observations of the [CII]158um emission line have revealed a strikingly uniform and highly turbulent interstellar medium (ISM) that is being blown away from the host galaxy isotropically. This is likely being driven by the energy and momentum injected by the central hyper-luminous super-massive black hole into the surrounding gas. The ISM properties of this outstanding galaxy, however, are still barely known. Here we propose to obtain ALMA band 7 and 8 observations of W2246 for the [OI]145um and [NII]122um emission lines, respectively, at an angular resolution similar to that of our [CII] data, ~0.35". The goal of the project is to use this suite of far-IR lines to characterize the density and kinetic temperature of the gas in the galaxy that represents the ultimate laboratory for studying and modeling ISM properties and kinematics under strong feedback. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2018-07-27T19:15:30.000 |
| 4234 | 2024.1.01586.S | 0 | A new Benchmark for CO Excitation in Typical High-z Galaxies | Observations of cold gas in high-z galaxies rely critically on the correction factors between the ground and excited states of CO; the golden standard to measure molecular gas masses. Yet, gas excitation studies of typical galaxies at high-z are still limited to small numbers of sources and transitions. We propose to greatly expand this knowledge by completing our ALMA program targeting a unique flux-limited reference sample of 14 galaxies from the ALMA Spectroscopic Survey (ASPECS) in the Hubble Ultra Deep Field. These galaxies span across the main sequence at z=1-3, already have partial CO, [CI] and continuum data in Bands 3 and 6 from the Large Program, and have uniquely-deep JWST, HST and MUSE imaging and spectroscopy. We target the missing CO transitions in Band 4, 5 and 7, obtaining simultaneous [CI] and dust continuum for free. While the Band 4 observations are nearly done, with a 100% detection rate so far, finishing the Band 5 and 7 observations remains critical to break existing degeneracies in the CO and [CI] excitation, the CO-to-H2 conversion factor and the gas conditions. This sample will form a new benchmark atlas for future surveys of molecular gas at high redshift. | Starburst galaxies | Active galaxies | 2025-11-13T15:00:27.000 |
| 4235 | 2018.1.00797.S | 30 | Probing the dense gas properties and star formation in a z = 3.6 lensed SMG using dense gas tracers and CO isotopologues | Although it is important to explore the molecular complexity of high-redshift galaxies, only a few studies of the various dense gas tracers and CO isotopologues have been performed so far because of the weak line fluxes when the source is not gravitationally amplified. We propose to carry out a multi-transition study of dense gas tracers and CO isotopologues towards one of the brightest lensed submillimeter galaxy at z=3.6. This study is only possible thanks to the unique ALMA instantaneous bandwidth and sensitivity. With just two frequency setups in the ALMA Band 3 and 4 we will be able to cover a total of ~70 GHz in the rest frame, equivalent to large line surveys in local galaxies. Using LVG models, we will be able to study in detail the physical conditions and the abundances of the dense star-forming gas in this extreme object. The proposed bands will naturally cover transitions of the CO isotopologues which will be compared to state-of-the-art models to constrain the star formation history and IMF. The proposed dense gas line survey and the expected spectral richness of this source will serve as a benchmark for future studies of high-redshift dusty star-forming galaxies. | Starburst galaxies, Gravitational lenses | Active galaxies | 2020-02-21T20:04:23.000 |
| 4236 | 2021.1.01262.S | 5 | High resolution characterization of early bulge structure and feedback in a z = 7.07 low-luminosity quasar | Recent ALMA observations of [CII] emission toward the z=7.07 low-luminosity quasar, J1243+0100, have shown following outstanding features: (1) massive host galaxy likely associated with a massive, compact bulge, and (2) fast AGN-driven [CII] outflow. However, due to the limited resolution of the previous work (0.7"), it was difficult to provide firm evidence of the bulge, as well as to investigate detailed properties of the [CII] outflow. In this program (0.23" resolution), we will spatially resolve these intriguing structures at [CII]. We will deliver the following. (1) Detailed gas dynamics: we will measure the rotation curve at r < 2 kpc of this quasar. By firmly capturing a steep rise in this curve, we can characterize the massive bulge even at z ~7. (2) Mapping the [CII] outflow: we will estimate various outflow properties as a function of the distance from the nucleus, providing a more faithful view on the nature of this AGN feedback. (3) Detailed gas distribution: We can compare the gas distribution of J1243+0100 with those of luminous quasars to study what is critically different between luminous and low-luminosity quasars on scales of kpc. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-12-21T20:08:37.000 |
| 4237 | 2021.1.01212.S | 10 | Is the star formation in one of the most massive cluster at z>1 fuelled by a cooling flow? | SPT-CL J2106-5844 (SPT2106; z=1.132) is among the most massive known galaxy clusters at z>1, and its BCG is accompanied by a ~70 kpc long star-forming filament identified in HST rest-frame UV images. Recent ALMA SZ, X-ray, and radio studies have revealed multiple mass and gas components, indicative of a recent cluster merger, and that the BCG is located within a cool X-ray core with strong radio jets along the same axis as the star-forming filament. The observed spatial correlation between the filament and cool core indicates that the starburst may be triggered by runaway cooling, analogous to cooling flow clusters at low z. As only one other high-z cluster has been found with similar properties, this would be a tremendous find, confirming that runaway cooling following the cluster merger could fuel star formation >8Gyr ago. Alternatives include triggering from a wet merger with the BCG, or uplifted cold gas from the radio jets. To distinguish between these alternatives, we aim to exploit ALMA's unrivaled capabilities to probe CO(2-1) emission from SPT2106 and to constrain the amount and velocity structure of the molecular gas associated with the BCG. | Galaxy Clusters | Cosmology | 2024-01-11T16:01:49.000 |
| 4238 | 2012.1.00837.S | 7 | Understanding Molecular Gas Accretion and Feedback from Supermassive Black Holes | We request short ALMA pointings toward the brightest cluster galaxies (BCGs) in the cooling clusters PKS 0745 and 2A0335+096. Both BCGs contain more than 10^{9} solar masses of molecular gas and nuclear star formation that rank among the largest in the low redshift Universe. The molecular gas, which probably formed from hot gas that cooled out of their X-ray atmospheres, may be fuelling the powerful AGN outbursts commonly observed as expanding radio bubbles, shocks and sound waves in the X-ray atmospheres of clusters. The short ALMA observations will immediately reveal relationships between molecular gas, cooling X-ray filaments of gas, star formation, and circumnuclear accretion disks fueling powerful AGN. We will search for the existence of high-velocity clouds of molecular gas found in a Cycle 0 ALMA observation of Abell 1664 that may have been ejected from the nucleus. The CO (3-2) images will probe nearer to the Bondi accretion radius in CO than has has been possible in the past, to determine whether AGN are likely to be fuelled directly by hot atmospheres or by molecular clouds. The velocity profiles and molecular gas mass distributions will provide new clues to the origin of the molecular gas through measurements of its angular momentum and kinetic energy content. The proposed ALMA observations will map the mysterious cold phase of the radio-mode feedback cycle, which has emerged as the ``new physics'' in galaxy formation. | Galaxy groups and clusters | Cosmology | 2015-10-17T17:07:24.000 |
| 4239 | 2017.1.01380.S | 119 | Are dense cores formed through shocks? An observational test in Ophiuchus | Dense cores are the places where stars are formed, and as such they provide the initial conditions for star formation. Several of the models that try to explain the dense core formation process involve shocks (either due to supersonic turbulence or by accretion shocks). However, no direct evidence for those shocks have been found until now. We just received ALMA Cycle 4 data on a starless core in Ophiuchus that shows clear evidence for gas recently affected by a shock (large abundances of CH3OH and spatial distribution anticorrelated with dense gas tracers, NH2D). These observations provide the first direct evidence for shocks around a dense core. We propose to expand the search for evidence of shocked gas on 3 more dense cores in Ophiuchus, repeating the succesful setup used in Cycle 4, to look for evidence of shocked gas around dense cores. This will be the first step into determining how common are shocks involved in the formation of dense cores. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-11-26T13:50:11.000 |
| 4240 | 2021.2.00008.S | 190 | Heating Processes in Supernova-Shocked Clouds: Multi-J CO Line Survey toward the Magellanic Supernova Remnants | We propose multi-J CO line observations of shock-interacting clouds in Magellanic supernova remnants (SNRs) to better understand heating processes of shocked gas, which are important in revealing supernovae impacts on both star formation and galaxy evolution. Most recently, we analyzed shocked molecular clouds in the LMC SNR N49 using the archival ALMA CO(J = 1-0, 2-1) datasets. High kinetic temperatures of ~40 K are only seen in the shock front, which suggests the presence of shock heating. Models predict that kinetic temperature should be proportional to SNR age. Since N49 is a middle-aged SNR at 4800 yrs, this offers us an opportunity to survey a sample of both younger and older SNRs that have evidence of interactions with molecular clouds to test these predictions by measuring the kinetic temperatures of shock heated gas. We propose to observe a sample of LMC SNRs with ages from 860 to 10000 years to directly constrain the time-dependent evolution of shocked gas in SNRs for the first time. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2023-09-21T08:26:22.000 |
| 4241 | 2022.1.00017.S | 0 | Multi-band sub-THz observations in NGC 1068: A test of the Unified Model of AGN | The active galactic nucleus (AGN) is one of the most energetic phenomena in the universe and may have played a fundamental role in galaxy evolution. The Unified Model of AGN has been proposed and favored to explain the large variety of AGNs. Submillimeter and mid-infrared interferometric telescopes have recently depicted a torus-shaped gas and a very compact (~1 pc), warm, and optically-thick dust ring that may obscure the central engine of NGC 1068. Nevertheless, the complete picture is still unclear because of the lack of spatial information on a large amount of cold dust at a parsec scale. Here we propose sub-THz (Band 8 and 9) observations in the center of NGC 1068, a Type-II Seyfert galaxy, down to 2-3 pc for the detection of extended (<10 pc), less optically-thick dust disk that the cold dust may associate with. We test if sub-THz continuum emission originates from the cold dust by (1) expected double-peaked structure in continuum images and (2) a radio-to-infrared spectral energy distribution (SED) fitting. We also obtain CO J=6-5 and J=4-3 line emission at the same time for an independent constraint of the torus physics. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-11-17T00:55:03.000 |
| 4242 | 2022.1.01268.V | 0 | Black Hole Dynamics and Achromaticity in the Shadow of Sgr A* | Black holes are the only objects in the Universe that allow us to probe fundamental physics from stellar to supermassive scales. They host extreme astrophysical environments near their event horizons with relativistic motion, high temperature plasmas, and powerful magnetic fields. The Galactic Center supermassive black hole, Sgr A*, is the only black hole we can observe in detail from the feeding source down to the event horizon. Here, we propose to use ALMA in a global VLBI array to capture and trace the plasma activities in the immediate vicinity of the event horizon of Sgr A*. The short dynamical time scale and daily broadband flares offer unique opportunities to study dynamics near the event horizon resolved in both time and space. The proposed observation will enable us to: 1) significantly improve the fidelity of horizon-scale Sgr A* images and enable movie reconstruction with better interferometric coverage; 2) understand the origins of near-horizon plasma variability; 3) resolve the base of a jet, if it exists; and 4) provide an independent test of the scale-invariance of the black hole spacetime. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-04-23T20:48:53.000 |
| 4243 | 2023.1.00665.S | 33 | Zooming in on protostellar disks in high-mass star formation | There is growing consensus that the formation of high-mass stars (>8 Msun) proceeds through disk accretion, similar to that of lower mass stars. However, there is a critical need for a large sample that can homogeneously resolve and characterise the properties of these disks. We propose to observe 30 nearby (<4.5 kpc) high-mass protostellar disk candidates, uniformly selected from the ALMAGAL large program. We will observe the sample in both continuum and line emission at 1.3 mm using molecular disk tracers like CH3CN, HC3N, and salt lines, as well as more diffuse gas tracers like H2CO and CH3OH. With high angular resolution of 0.05'' (~150 au) we will resolve and characterize the physical properties of the candidate disks. Covering scales up to 0.6'' (a few thousand au) we will trace the flow of gas in the transition region between envelopes and the disks within them. Our observations will be combined with the archival ALMAGAL observations that observed these sources with 0.3-30" resolutions, following gas flows from clump scales down to individual protostars to paint a comprehensive and diverse picture of infall, accretion, and outflow processes in high-mass star formation. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2024-10-19T19:13:11.000 |
| 4244 | 2021.1.00536.S | 14 | Role of ambipolar diffusion in disk formation around protostars | The non-ideal MHD effect, ambipolar diffusion, is one of the mechanisms suggested to avert the magnetic braking catastrophe and enable the formation of large-scale Keplerian disks around protostars. With efficient ambipolar diffusion in a collapsing dense core, the ions and neutrals can have a relative drift, and the magnetic field can partially left behind the infalling neutral flows. The strength of ambipolar diffusion in protostellar sources has not yet been observationally constrained. L1527 IRS is a young protostar with a large Keplerian disk with a radius of 70 au. If ambipolar diffusion indeed plays an important role in disk formation in L1527 IRS, from theory, the ion-neutral drift at a velocity of a few times 0.1 km/s is expected to occur in its protostellar envelope on a 1000 au scale. Our theoretical calculations and imaging simulations show that H13CN and H13CO+ can be used to trace the relative motion between ions and neutrals in protostellar envelopes. Therefore, we propose ALMA observations in H13CN and H13CO+ (3-2) at a high velocity resolution of 0.05 km/s to probe the ion-neutral drift in L1527 IRS. | Low-mass star formation | ISM and star formation | 2023-06-23T04:10:12.000 |
| 4245 | 2019.1.01212.S | 7 | Deep ALMA Imaging of an Accreting Planetary-mass Companion | Probing the accretion disks around planetary-mass companions (PMCs; M < 20 Jupiter masses, orbit > 100 AU) provides a new avenue for understanding the origin of PMCs and the physical properties of circumplanetary disks (CPDs). Previous shallow attempts to observe CPDs with ALMA have resulted in upper limits. An emerging consensus is that PMC disks are fainter than expected, so hours of integration are almost certainly necessary to detect them. It has been proposed that PMC disks are faint because they are very compact and optically thick. Alternatively, radial drift might be exceedingly fast such that dust grains are highly depleted. Here we propose an ambitious Band 7 program to definitively measure dust and gas emission from an accreting PMC. This will be by far the deepest and most sensitive sub-millimeter imaging of a PMC and represents the best opportunity thus far for ALMA to detect and characterize a CPD. These observations also have the potential to detect Keplerian rotation which would enable a dynamical mass measurement in the planetary regime. Finally, we emphasize that even a non-detection will have important implications for the physical properties of CPDs. | Exo-planets | Disks and planet formation | 2022-11-10T03:18:49.000 |
| 4246 | 2018.1.01524.S | 25 | The Dynamics of the 200au Disk in the O-Type Protostar G17.64+0.16 | At the very highest resolution available to ALMA (20mas) we imaged the continuum emission, finding an elongated structure, the dust disk, around G17.64+0.16 in Cycle 5. Now we wish to image deeper to detect the molecular line emission and study the dynamics. G17.64+0.16 is thought to be a proto-O-star (>10^5Lo) and we confirmed it is surrounded by a cold dust disk, in agreement with multi-baseline IR interferometry indicating a hot dust disk. In protostellar models, G17 is in a late phase, contracting from a swollen configuration to a main-sequence configuration with a radiative stellar envelope now driving a wide angle `disk' wind. Our Cycle 2 data indicate that SiO is tracing this rotating disk-wind (similar to Orion Source I). We have detected, and resolved the disk in the continuum emission but we do not detect SiO at the highest velocities. We wish to map much deeper to understand the dynamics of the disk from the resolved molecular line emission - this will allow us to (1) confirm the O-star nature from the velocity pattern, (2) investigate for the presence of a binary, (3) Provide insights into te spiral features - due to gravitational instabilities or a binary. | Disks around high-mass stars | Disks and planet formation | 2020-11-07T20:14:57.000 |
| 4247 | 2021.1.00094.S | 33 | Do active galactic nuclei lead to quenching via a depletion of the molecular gas reservoir? | Active galactic nuclei (AGN) are often invoked as a feedback mechanism that can lead to the cessation of star formation ("quenching") in galaxies. However, the observational evidence supporting the AGN-quenching connection is ambiguous and the role of AGN on truncating star formation remains debated. We propose a simple, but powerful, experiment to connect the impact of an AGN on the galactic gas reservoir, and hence its ability to form stars. Using kpc-scale emission line maps of galaxies in MaNGA, we have identifed 11 strong AGN observable by ALMA. We propose to obtain CO(1-0) maps matched at the same spatial scale as MaNGA, in order to combine information about the gas, star formation rate and stellar mass. Since galaxies are known to show a tight correlation of their surface densities of stellar mas and molecular gas, we can quantify whether the regions photoionized by the AGN exhibit a deficit of molecular gas, which would in turn impede star formation due to lack of fuel. By combining the molecular gas and star formation rates, we can additionally test whether the star formation efficiency is lower in the AGN regions. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-04-08T12:46:38.000 |
| 4248 | 2017.1.00350.S | 20 | A unique window on circumbinary planet formation at only 45pc | Our current picture of circumbinary planet formation is highly uncertain. How the binary influences collisions, how far these planets migrate, and why they end up near the inner stability limit is unknown. To make progress, systems with known binary orbits where the disk can be imaged at a resolution comparable to the disk inner radius will be immeasurably valuable. Thus, we propose 2.8h of high resolution Band 6 observations of the nearby HD 98800 system (~8Myr old in TWA @ 45pc), which is host to a bright compact circumbinary disk. The known binary orbits make this a benchmark system for binary-disk interaction. The hydrodynamic and n-body response of the disk will be quantified by models, which will be used as context for the interpretation. Specifically, the innermost extent where dust survives tells us how far in circumbinary planets can form, and thus how far they must migrate. If CO is detected, line imaging provides detailed kinematics and insights into disk warping and viscosity. If misalignment is still present at 8Myr, the implication is that circumbinary planets need not all be coplanar, and may be much more common than around single stars. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2019-01-26T12:49:14.000 |
| 4249 | 2023.1.00213.S | 0 | The Sunyaev-Zel'dovich effect toward a distant galaxy cluster at z=1.7 | We propose Band 3 observations of the Sunyaev-Zel'dovich effect (SZE) toward ACT-CL J0459.6-4946 at z=1.7, one of the most distant galaxy clusters with high quality X-ray data available. This object has been detected at high significance in SZE surveys by the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). Our immediate objectives are i) mapping the projected gas pressure and reconstructing the inner pressure profile, ii) measuring gas temperature and density profiles in conjunction with existing X-ray data, and iii) searching for evidence of disturbances including shocks. This will be among the first such measurements at z>1.5 and can only be accomplished by deep ALMA+ACA observations. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2025-04-16T02:17:01.000 |
| 4250 | 2017.1.00117.S | 107 | Searching for Accretion Luminosity Variability in Deeply Embedded Protostars: The Second Epoch | Low-mass stars form via gravitational collapse of molecular cloud cores. The evolution of the mass accretion onto a forming protostar depends on the rate at which the interior of the core collapses, the significance of a circumstellar disk as a temporary mass reservoir and transportation mechanism, and the physics of how the inner disk accretes. Despite a clear requirement for time dependency in the accretion rate onto deeply embedded protostars and a large number of theoretical mechanisms for powering variability, our understanding of both the timescale and amplitude of variability is almost entirely unconstrained. In Cycle 5 we propose to obtain second epoch 230 GHz continuum brightness measurements for 16 deeply embedded protostars in Serpens at ~100 AU resolution. These results will be compared against 2016 ALMA (and 2010 CARMA) observations to uncover low-amplitude (~10%) accretion variation on few year timescales. These observations, vital for discriminating between theoretical models of episodic accretion onto deeply embedded protostars, include one known sub-mm periodic variable. | Low-mass star formation | ISM and star formation | 2019-10-03T15:52:11.000 |
| 4251 | 2024.1.01085.S | 0 | ALMA follow-up of Little Red Dots: Efficiently testing black hole growth/feedback models with multiphase gas kinematics | JWST has revealed a previously unknown population of dust-reddened active galactic nuclei (AGN), so-called little red dots, raising questions about the abundance of SMBHs in the early universe. These red AGN may represent a transition phase from obscured, rapidly accreting BH seeds to unobscured, blue quasars, therefore providing a key laboratory for building our understanding of the dominant growth mechanisms in high-redshift SMBHs.We propose targeted ALMA follow-up of 3 of the brightest little red dots with existing JWST spectroscopy. Specifically, we propose low frequency observations simultaneously targeting the CO(7-6) and [CI](2-1) lines to probe multiple phases of the ISM and: i) search for molecular outflows via CO, determining if the LRDs are indeed in the "blowout" phase, removing their obscuring gas/dust, ii) probe the dispersion of neutral ISM via [CI], placing the LRDs on the M-sigma relation and determining whether the black holes are overmassive relative to their host galaxy, and iii) provide the deepest ever constraints on the cold dust content of the LRDs, which has yet to be detected despite the significant dust attenuation inferred from the optical SEDs | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-10-15T01:39:47.000 |
| 4252 | 2019.1.00580.S | 29 | Search for time variability in coronal syncrotron emission in a nearby Seyfert galaxy | AGNs host hot plasma, namely coronae, emitting intense X-ray photons. Like the Sun, these coronae are believed to be heated by their magnetic activity. However, coronal magnetic activity in AGNs have never been measured. Utilizing ALMA Cycle-4 observations (#2016:1:01140:S), we successfully detected coronal radio synchrotron emission from nearby Seyferts. This discovery has been first achieved by ALMA's high angular resolutions and sensitivity at the millimeter bands. The inferred magnetic field strength is of ~10 G on scales of ~40 Schwarzschild radii from the black holes. Moreover, the coronae are found to be composed of thermal and non-thermal electrons. Our theoretical study of particle acceleration in coronae suggests that shock acceleration can generate such non-thermal electrons and fast time variability down to 100 s is expected. Here, we request ALMA Band-3, 4, and 6 monitoring observations toward IC 4329A again in order to search for time variability of coronal synchrotron emission. By establishing the variability of coronal synchrotron emission, ALMA will enable us to constrain the emission region size and the production mechanism of high energy particles in coronae. | Spiral galaxies | Local Universe | 2022-10-13T00:00:00.000 |
| 4253 | 2021.1.01389.S | 11 | The Molecular Gas Reservoirs of Epoch of Reionization Galaxies | Molecular gas has never been studied in normal epoch of reionization galaxies (z>~6). This is a fundamental gap in our understanding of how high-z galaxies assembled their mass. Now we can dramatically improve this situation thanks to the newest samples of especially bright z>6 galaxies. In fact, recent advanced simulations of high-z galaxies predict that high-J CO lines should be detectable in several of the brightest known z>6 galaxies with only modest ALMA programs (few hours per source). The CO luminosities of local galaxies, however, are ~x3 fainter than those predicted for high-z galaxies. And they are even fainter in local metal poor galaxies. Here we will provide the first empirical evidence to either validate the theoretical predictions or to place very strong constraints on the CO luminosities that we should expect from normal z>6 galaxies. We have selected a z=6.577 source that should be particularly amenable to detections of CO(7-6) and CO(6-5). If the theoretical predictions are correct, this will be the first z>6 galaxy for which we can study its molecular gas reservoir and it will open the opportunity for a sistematic study of the molecular gas in EoR galaxies. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2023-01-28T11:19:11.000 |
| 4254 | 2021.1.00135.S | 35 | Gravitational Instability as a Cause of Rapidly Mass-accreting AGNs | Secular processes are thought to be crucial in triggering accretion onto super-massive black holes. Through this Cycle, we want to test the gravitational instability of gas as a fundamental cause of mass accretion by 50-pc-resolution CO(J=2--1) ALMA observations for well-matched four pairs of high and low Eddington-accretion-rate AGNs. Each pair has similar (i) black hole masses, (ii) stellar masses, and (iii) host galaxy morphologies, but different accretion rates by ~ 1.5-3 dex. Focusing on each of AGN pairs, we will quantitatively discuss whether the gas instability on 300-pc scale circumnuclear disks triggers the mass accretion, specifically addressing three questions: (1) Is the gas mass surface density high?, (2) Is the CND unstable due to a low Toomre's Q value?, and (3) Is the angular momentum transferred from inner to outer regions?. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2022-12-08T00:00:00.000 |
| 4255 | 2017.1.00433.S | 13 | The Birth of Super Star Clusters at 0.5 Parsec Resolution | Our recently delivered B7 mosaic of the central regions of NGC 253 at 1.6 pc resolution uncovers highly-structured bright emission and a number of compact sources that have all the markings of nascent very massive star clusters (super star clusters). These objects are very bright in continuum and HCN 4-3, possess dynamical masses of approximately a million solar masses, and are unresolved in our 1.6 pc resolution data. We propose to obtain 0.5 pc resolution data in the central field encompassing these objects, with enough sensitivity to ensure their detection and conclusively measure their sizes and kinematics. These measurements will allow us not only to obtain accurate masses and determine the structure of these objects, but also to study feedback signatures and processes that may stop their growth. In particular we will look for the imprint of strong radiative feedback by estimating FIR optical depths from dust surface brightness and comparing them to local kinematics from high S/N line profiles. NGC 253 is the best source to carry out these high spatial resolution observations. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2019-03-13T15:48:16.000 |
| 4256 | 2023.1.01591.S | 0 | The missing piece of disc evolution: disc demographics in 25 Orionis, an old region with low UV radiation | Understanding protoplanetary disc evolution is essential to characterise the environment where planets are assembled and to explain the diversity of the currently detected exoplanets. Testing disc evolution models with observations relies on collecting large samples of discs in star-formation regions (SFRs) of different ages. However, while several young SFRs have been surveyed in the last years, only one old region, Upper Sco, was observed so far (with less than 30% completeness). We argue that most of the evolutionary trends detected between young SFRs and Upper Sco could be explained both by the effect of time-dependent internal disc processes and interaction with the environment (external photoevaporation). We propose to observe the population of class II discs in 25 Orionis, a young, low-mass SFR as old as Upper Sco but much less affected by external photoevaporation. These observations will allow us for the first time to disentangle the contribution to disc evolution of internal processes and interaction with the environment. | Disks around low-mass stars | Disks and planet formation | 2025-06-26T01:10:44.000 |
| 4257 | 2013.1.01302.S | 2 | Resolving CO and Dust Emission in the Phoenix Cluster - The First Bonafide Cooling Flow? | Early observations of galaxy clusters predicted that the hot intracluster medium should cool at rates of 100-1000 Msun/yr, fueling extreme starbursts in the clusters' cores. This phenomenon went unobserved for decades. Recently the Phoenix cluster was discovered at z=0.597, harboring an 800 Msun/yr starburst at its center - the highest star-formation rate ever observed in a central cluster galaxy by a factor of 5. Here, we propose to obtain data at redshifted CO(3-2) with 0.7" resolution in order to determine: i) the morphology of the cold molecular gas; ii) the kinematics of the cold gas, searching for evidence of outflow/disruption; and iii) the IR-derived star formation rate, free from AGN contamination. The kpc-scale distribution of the cold gas and dust can only be studied with the superior resolution and sensitivity of ALMA. This program compliments recently-approved programs with HST, Chandra, and Gemini, allowing us to track the hot ICM as it cools over 7 decades in temperature, ultimately into fuel for star formation, and shedding new light on this uniquely extreme system in which cooling appears to be briefly dominating over feedback. | Starburst galaxies, Galaxy Clusters | Active galaxies | 2015-09-02T19:09:57.000 |
| 4258 | 2022.1.00742.S | 35 | A Survey of Vertical Structure in Protoplanetary Disks Across Nearby Star-Forming Regions | Dust dynamics and growth are key physical processes during the early stages of planet formation. Previous studies indicate a high degree of vertical settling which has a severe impact on the planet formation potential of disks. The vertical structure of protoplanetary disks is best-studied in systems that are viewed edge-on. Using SED's to identify candidate edge-on disks and HST imaging to confirm them, a sample of 25 edge-on disks have been confirmed in nearby Star Forming Regions. To date, only 8 of them have been imaged with ALMA at the 0.1" resolution needed to characterize the midplane layer of mm-size dust. We propose to survey 8 new edge-on disks in the Chamaeleon, Lupus, and Ophiuchus clouds, i.e., all those observable in C9, to double the sample size. By comparing CO 3-2 gas emission to the distributions of small grains (from HST scattered light images) and large grains (band 7 continuum emission), strong conclusions will be drawn about the concentration of solids in the disks. This is mandatory to characterise the disk midplanes, where pebbles concentrate and planets form. | Disks around low-mass stars | Disks and planet formation | 2024-11-06T17:51:53.000 |
| 4259 | 2019.1.00113.S | 6 | The parsec scale view of the starburst ISM through molecular diagnostics | Extreme activities in starburst galaxies have a direct impact on their molecular interstellar medium (ISM). These effects on the ISM are most prominent in the vicinity of young stellar clusters on parsec-scales, dominated by feedback in the form of heating and outflows. Thanks to its proximity and brightness, the starburst galaxy NGC 253 allows for the most detailed studies of the ISM in a starburst environment using (sub-)millimeter molecular lines. These lines are an effective probe due to their large penetration depth. Using measurements of a variety of molecular diagnostics, we will study the molecular cloud physical properties, the chemical composition caused by various heating sources, extreme excitation conditions, and cluster-scale outflows. We intend to perform a spectral scan in Bands 6 & 7 with 0.2" resolution in the central 15" of NGC 253 to cover all transitions of interest. Short spacing information is already available from our Cycle 5 project. Our spectral scan will efficiently reveal the highly excited physical conditions and signatures of feedback in the nearest starburst galaxy NGC 253. | Galaxy chemistry, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2022-07-19T13:44:55.000 |
| 4260 | 2021.A.00028.S | 5 | Removing line blending contamination from H3O+ Band 10 observations of PKS1830-211 | ALMA Band 10 observations of hydronium (H3O+) and oxidaniumyl (H2O+) have recently been obtained in the z=0.89 molecular absorber toward the bright quasar PKS1830-211. These observations allow us to probe in a unique way the chemistry of the oxygen hydride ion family, and measure in a robust, self-consistent analysis the molecular hydrogen fraction, the cosmic-ray ionization rate, and the electron fraction in the disk of a z=0.89 galaxy. The molecular absorber toward PKS1830-211 is the only intermediate-to-high redshift object for which such a detailed chemical analysis can be done, providing a benchmark for distant star-forming galaxies. However, one line of H3O+ is partly blended with absorption from H2^18O and the limited S/N of the H3O+ profile prevents us to correctly analyze the data. Although H2^18O has already been observed twice in this source, its last observation happened back in 2019, and the absorption profile is known to be variable on yearly timescale. We therefore propose to perform a short observations of H2^18O in Band 7, which will allow us to assess the time variability and correct the H3O+ spectrum, to fully exploit this remarkable Band 10 data. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-03-05T10:25:17.000 |
| 4261 | 2016.1.00515.S | 41 | Signature of a Planet in the Gyr-old Eccentric Debris Ring of HD 202628 | Opportunities to investigate the diversity of mature analogs to our own Solar System are rare. Therefore, we propose ALMA continuum mapping in band 6 to observe the sub-mm excess from the Gyr-old debris ring surrounding the Sun-like star HD 202628. As revealed in scattered light by HST, HD 202628 is surrounded by a large and eccentric debris disk, as confirmed by Herschel/PACS low resolution images, showing a "pericenter-glow" at the inferred position angle of periastron. The debris ring also possesses a sharp inner egde, and its properties are strikingly similar to the Fomalhaut debris ring. This likewise suggests ring sculpting by a distant eccentric planetary companion. ALMA observations will constrain the detailed architecture of this debris disk and map the distribution of the large parent dust grains with respect to the scattered light. In conjunction with the HST and Herschel data, the ALMA results will be used to build a comprehensive model of the ring dust population. They will provide a key dynamical constraint on the properties of the ring perturber, the most distant one ever inferred around a solar-type star. | Debris disks, Exo-planets | Disks and planet formation | 2018-02-10T15:22:53.000 |
| 4262 | 2023.1.01198.S | 0 | Investigating the torus of the planetary nebula NGC 6302 as a testing bed of dust formation | We request 13CO 3-2 and CI mosaic mapping of the planetary nebula (PN) NGC6302 to decipherer the dust formations process. This PN is known to have a dense molecular torus at the waist of the bipolar outflow. The apparent size of this torus is one of the largest (~25arcsec) amongst PNe. The torus is regarded to be the site of forming crystalline/amorphous silicates and polycyclic aromatic hydrocarbons (PAHs). By combining the proposed 13CO 3-2 map with an archival 13CO 2-1 map, the molecular gas temperature and (column) density will be mapped in the torus with a 0.66 arcsec resolution. A 3D map of CI will be used to investigate the relative morphology of CI with respect to CO. The approved JWST spectral map will provide measurements of dust features and atomic lines, giving the dust and ionised gas densities, the temperatures and the ionisation state. The measured spatially distributions of different dust species will be compared with molecular and atomic temperature and density distributions, determining what types of dust are formed under what density/temperature. This will be an important step of understanding how to form and process dust in circumstellar environment. | Evolved stars - Shaping/physical structure, Evolved stars - Chemistry | Stars and stellar evolution | 2025-10-16T12:11:59.000 |
| 4263 | 2018.1.01774.S | 6 | First characterisation of a directly imaged protoplanet and its natal environment with ALMA | With this proposal, we aim to characterise the transition disk around PDS 70, in particular the local environment of PDS 70 b, a protoplanet which we recently discovered with the SPHERE imager. We will observe PDS 70 b and its direct environment at high angular and spectral resolution using ALMA in Band 7 to study the gas kinematics of the CO isotopologues and trace the planets imprints on the velocity field. Further, we will search for circumplanetary dust in the continuum. If detected, this would be the first direct detection of a circumplanetary disk. The proposed observations will allow for the characterisation of this planetary system, observed in both, NIR and sub-mm regime. They will provide excellent and unique laboratory for understanding the formation and evolution of CPDs, the accretion onto the planet and through the TD gap onto the central star itself. | Exo-planets | Disks and planet formation | 2022-09-14T19:11:51.000 |
| 4264 | 2023.1.01016.S | 0 | Quenching the first massive galaxies: a detailed look at the leftover ISM in the earliest confirmed galaxy at z=4.658 | JWST observations of massive quiescent galaxies (QGs) at z>3 have yielded many surprises, potentially upending existing models. Undoubtedly, ALMA's FIR sensitivity will provide powerful constraints on the cold gas content of those earliest QGs -- the critical piece missed by JWST -- that are key to determining the process by which these galaxies formed and quenched. In this program, we propose 7.4-hour Band 7 observations to measure the dust continuum, at a 0".2 angular resolution, of a massive (logM=10.7) QG that is, by far, the earliest known case with a spectroscopically confirmed redshift of z=4.658 with JWST. We will measure the galaxy's dust mass, gas fraction and depletion time. The proposed high angular resolution will enable a spatially resolved view on the correlations among the cold-gas properties (ALMA), stellar-mass distribution (JWST) and star formation history, allowing us to dissect the physics behind highly efficient early growth and quenching processes in this best candidate of the first generation of massive QGs, at a level of detail never before possible beyond z>3. | Early-type galaxies | Galaxy evolution | 2025-06-21T21:55:30.000 |
| 4265 | 2016.1.00624.S | 84 | The fate of star-forming clumps during the winding-down of star formation | We propose a high-resolution CO line and dust continuum imaging program of a sample of six massive star-forming galaxies at z=0.5-0.6 in order to investigate in detail the star formation processes and the fate of the star-forming regions during the winding-down of star formation. We will derive the mass distribution, the kinematics and the velocity dispersion of the molecular gas at the scale of the star-forming regions themselves, namely 1 kpc or about 0.15". This will allow us to characterize star formation on subgalactic scales, notably through a spatially-resolved Kennicutt-Schmidt relation, to observe the inner morphology of the disk, and to test the virialization of the star-forming clumps. This study, which complements an ALMA cycle 3 pilot project, is meant as a high-resolution step forward of the IRAM PHIBSS and PHIBSS2 programs investigating early galaxy evolution and star formation from a larger statistical sample of about 200 sources at different redshifts but with lower resolution. ALMA resolution and sensitivity will allow us to reach kpc-scales, which is crucial to our understanding of the transitional period of the winding-down of star formation. | Starbursts, star formation | Active galaxies | 2018-02-28T23:00:56.000 |
| 4266 | 2016.1.01149.S | 26 | Measuring Molecular Gas in Unseen Galaxies: A Survey of 100,000 Cubic Mpc between z=1-5 | Molecular gas is central to the formation of stars in galaxies. However, at high redshift, it has been detected only in the most massive and luminous systems. Sensitivity to low mass systems allows for better exploration of the overall molecular gas abundance, metal production and galaxy evolution within the Universe. We propose to measure the distribution of molecular gas in the early Universe (z>1) using the technique of ``intensity mapping", with which low and intermediate-mass galaxies are detectable as integrated ensembles. We propose an intensity mapping experiment to measure the broad population of molecular-gas bearing galaxies between z=1-5, utilizing the emission arising from several bright CO rotational transitions. The proposed observations will improve on the sensitivity of present power spectrum measurements by nearly an order of magnitude. | Surveys of galaxies | Galaxy evolution | 2019-05-15T00:00:00.000 |
| 4267 | 2013.1.01299.S | 4 | ALMA Observations of z~6.7-6.8 Galaxies with Strong Optical Nebular Emission: Re-Evaluating ALMA's Potential for Detecting z>6 Galaxies | Recently, Ouchi et al. (2013) has reported that they could not detect one of the brightest Ly-alpha emitters at z=6.595 (named Himiko) either in continuum or in [CII] despite their deep ALMA integrations. Considering the large star formation rate (SFR) of ~100 Musn/yr derived for this galaxy from the rest-frame UV/optical observations, this means that this galaxy is abnormally deficient in [CII] and far-infrared luminosities, suggesting the possibility that galaxies at such high redshifts may be quite poor in dust and metal. Although this is exciting news, if such conditions are prevalent at high redshift, this would severely limit ALMA's potential for detecting z>6 galaxies. Here, we propose to make similar observations for two comparably bright z=6.7-6.8 galaxies. These galaxies are cluster-lensed, so their intrinsic SFRs are ~10 Msun/yr or less. Also, they show a sign of having strong nebular emission in the rest-frame optical. Together, these factors may increase the chance of [CII] and dust continuum detections, thereby shedding new light on the properties of z>6 galaxies. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2016-09-30T23:28:25.000 |
| 4268 | 2018.1.00276.S | 97 | Running on Empty: Probing the Gas Reservoirs of Lensed Quiescent Galaxies at z=1.6-3.2 | Using HST imaging and follow-up rest-frame optical spectroscopy, we have identified a remarkable sample of seven strongly-lensed massive (10.5 | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2020-09-06T18:11:52.000 |
| 4269 | 2023.1.01037.S | 0 | CF+ as a proxy for C+ in low metallicity environments: velocity resolved observations towards N159 W in the LMC | The [CII] 1.9 THz transition is an excellent tracer of the far-UV field (6 eV < h < 13.6 eV) generated by massive stars, since it dominates the cooling of atomic gas at low fields (Go < 10^3) and low density (n_crit([CII]) ~3×10^3 cm^3) in Photon-Dominated Regions. Nonetheless, the recent shutdown of the SOFIA Observatory closed the access to the 1.9 THz frequency window for the foreseeable future, so finding chemically equivalent but from ground accessible tracers is an ongoing effort. In that context, fluoromethylidynium (CF+) has been proposed as a proxy for C+ emission and tracer of H2 abundance, due to its simple chemistry depending only on F, C+, H, and H2 abundances via the HF + C+ -> CF+ + H formation reaction. While there is ongoing efforts in assessing the potential of CF+ as a C+ proxy in Galactic solar metallicity environments (e.g, Orion, M17SW, NGC1977, etc.), CF+ observations toward sub-solar metallicity environments are entirely missing. Therefore, we propose to map the CF+ J=1-0 102.6 GHz ground transition towards N159 W in the LMC, where the [CII] and [13CII] transitions have been detected, testing the role of CF+ as C+ proxy in low metallicity environments. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2025-04-22T15:47:48.000 |
| 4270 | 2021.1.00802.S | 0 | Mapping Flows of Gas Around 0.2 to 310 Lsun Protostars: ALMA Imaging of JWST Targeted Protostars | Understanding the origins of stellar masses requires a detailed accounting of the flows of mass - i.e. infall, accretion, and outflow - within a protostellar system. We propose to observe three protostars selected from a JWST cycle 1 GO program; these observations of the 230 GHz continuum and molecular lines - including CO and its isotopologues, H2CO, SiO, and N2D+ - will complement JWST measurements of accretion and shock lines by providing kinematics and by detecting cold gas invisible to JWST. With the large dynamic spatial range afforded by the combined ALMA+ACA+TP arrays, we will directly measure the structure and kinematics of the infalling envelope gas and the velocity and mass distribution of the envelope gas swept up by the accretion-driven outflows. These observations will measure the effect of accretion driven feedback on the envelope, determining the mass and momentum of the swept up shell, and in combination with the JWST information on shocks, test models of the entrainment of envelope gas in outflows. The proposed observations will also be used to search for high velocity gas in the cavity cleared by the outflow. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2023-07-25T18:43:28.000 |
| 4271 | 2013.1.00448.S | 4 | Origin of warm water emission in low-mass protostars | Water plays an important role throughout the entire star formation process, from cores to disks. In the cold dense outer parts of the protostellar envelope, water is the main constituent of the icy grain mantles. When the grains are heated above 100 K, water is released into the gas phase. Previously, we successfully observed warm water towards four deeply-embedded (Class 0) low-mass protostars. The observations show compact, narrow warm water lines on scales <100 AU, but its origin remains elusive (hot core, disks, or shocks). To determine the location of the warm water emission, we propose to observe the two isotopologues HDO and H2-18O in band 6 and 8 towards four sources that are more evolved (Class I) to further investigate and constrain the origin of the warm water emission and how this is affected by the evolution of the protostellar system. The observations will be able to, for the first time, constrain the location and abundance of warm water vapor in these objects. | Low-mass star formation, Astrochemistry | ISM and star formation | 2016-07-03T22:39:25.000 |
| 4272 | 2019.1.00255.S | 24 | Earliest Stage of Massive Binary Formation in Infrared Dark Cloud | We propose to carry out a zoom-in observation toward a massive proto-binary candidate in a massive protostellar core (about 33 solar masses) with an angular resolution of 0.025" at 230 GHz, corresponding to 125 AU. The massive core was previously observed with ALMA at a 0.2" resolution (best so far). The continuum image shows a hint of an elongated structure with a potential binary fragmentation at a separation of 0.2". The binary interpretation is further supported by the fact that the core shows two bipolar outflows in the CO and SiO data cubes. The candidate binary, if confirmed, will provide a new example of the earliest phase of massive binary formation because the region is dark at infrared wavelengths up to 100 micron. Our main goal is to confirm the binary and measure their separation using the 1.3 mm continuum. Using the H2CO lines, we will estimate the temperature and the mass. We will also use CO and SiO to trace the origins of the two bipolar outflows and thus the accretion disk orientations. We will compare with a slightly more evolved binary (with tiny HII regions) from Zhang et al. (2019) to study the evolution of massive binary at early stages. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2022-11-04T19:58:04.000 |
| 4273 | 2017.1.01145.S | 17 | Out of the Frying Pan, into the Fire: the Onset of Star formation in Gas entering the Central Molecular Zone | We aim to map a cluster of massive, dense cores identified in the highly turbulent 1.6deg cloud, thought to be just entering the extreme environment at the center of the Milky Way: the Central Molecular Zone (CMZ; inner ~300 pc of the Galaxy). While enormous effort in recent years has gone into the studying the gas and star formation properties of the inner CMZ of our Galaxy, we understand relatively little about the physical properties, kinematics, and star formation of the gas entering the Galactic Center.The discovery of massive, dense cores in the 1.6deg cloud with the large SMA survey of the CMZ (CMZoom) presents a unique opportunity to better understand the nature of the gas that flows into the center of the Galaxy as well as the star formation in this extreme environment. Understanding the nature of the gas that flows into our Milky Way center will provide a fundamental ground truth for extrapolation to other galaxies. | High-mass star formation, Intermediate-mass star formation | ISM and star formation | 2019-12-10T18:09:58.000 |
| 4274 | 2016.1.00972.S | 82 | Revealing the Cause of "Starburst"-like Conversion Factors in Nearby Galaxy Centers | We propose to take a key step in understanding what physical processes control the CO-to-H2 conversion factor by using ALMA to characterize molecular gas in galaxy centers where we observe low, starburst-like Xco. We will combine existing 12CO (1-0), 13CO and C18O (2-1) observations with 13CO and C18O (3-2) and dust continuum at matched GMC-scale (50-60pc) resolution. The spectacular sensitivity and resolution of ALMA make these faint diagnostics easily obtainable in nearby galaxies for the first time. In particular, the ability to measure multiple rotational levels of optically thin 13CO and C18O emission lets us self-consistently measure cloud masses and excitation temperatures. Using these observations we will test several hypotheses for why Xco is low in these regions: (1) enhanced temperature and/or decreased density in virialized GMCs, (2) CO emission from molecular gas not associated with GMCs or (3) GMCs that are unbound or under external pressure. The study we propose is the necessary, timely and feasible next step towards understanding Xco and will provide crucial information for future studies attempting to measure molecular gas masses in galaxies across the Universe. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2018-01-06T04:23:28.000 |
| 4275 | 2023.1.01567.S | 0 | Big Three Dragons: Spatially Resolving the Ionized Gas and Dust Structures of the Bright Merging System in the EoR | Recent high angular-resolution observations successfully revealed clumpy and multi-phase ISM structures in galaxies at redshift z > 6. We propose 0".15 (0.77-kpc scale) [OIII] 88 um observations of a starbursting major merger at z=7.1521, B14-65666 (a.k.a. Big Three Dragons). The low angular resolutions of archival ALMA data prevent us from even resolving the merging two clumps. We request a ~x4 better resolution to investigate dusty/unobscured starbursting merging morphology. Importantly, the galaxy is observed with JWST NIRCam and NIRSpec IFU. These observations will provide the spatial distributions of young stars (UV, [OIII]), matured stars (optical), warm ionized gas ([CII]), and dust with the same angular resolutions. In particular, we will address the spatial distributions of the [OIII]/[CII] ratio, the relation between dust morphology and color gradient, and accurate gas-phase metallicity of the two merging clumps using the combination of JWST[OIII]5007 and ALMA[OIII]88 lines. Thus, the requested high angular resolution, comparable to JWST observations, is timely required to maximize the synergy between ALMA and JWST. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 4276 | 2016.1.01313.S | 16 | HD as a powerful tool to trace gas flows in primordial galaxies | Gas flows are recognised to be fundamental processes driving galaxy evolution. Observationally gas outflows and inflows in galaxies are very difficult to probe, and in particular their molecular phase. This is even more difficult in primordial galaxies, since steep metallicity evolution makes traditional molecular tracers even more unreliable. The (1-0) transition of deuteriated molecular hydrogen, especially if seen in absorption, is potentially a perfect tracer of the column of molecular hydrogen, completely independent of metallicity and of gas excitation. Through a Cycle 2 programme we have recently obtained the first detection of HD(1-0) in absorption in a lensed galaxy at z=5.6. This is a truly revolutionary discovery. In this system HD is tracing both outflowing and inflowing gas, with unprecedented accuracy. We hereby propose to followup on this discovery to map HD absorption with higher sensitivity and higher angular resolution throughout the entire lensed galaxy, hence providing the most detailed picture of the outflowing and inflowing gas in a primordial galaxy. We also propose to target two additional water transitions to constrain the physics of the outflowing gas. | Gravitational lenses | Cosmology | 2017-11-02T17:57:41.000 |
| 4277 | 2015.1.01538.S | 26 | Giant molecular clouds properties along the bar of NGC3627 | Nearby galaxies provide the opportunity to study galaxy processes on large scales, while still being close enough to reveal the local details. ALMA has the ability to resolve star-forming structures in nearby galaxies with unprecedented sensitivity (in a reasonable amount of time). This will soon increase the number of giant molecular clouds observed in nearby galaxies, so far very small. A statistical study of the influence of global structural variations on the properties of GMCs will then be possible. We ask for observations of CO transitions in the bar region of NGC3627, where it will be possible to resolve clouds of 30 pc size, This spatial resolution represents an improvement of one order of magnitude with respect to previous observations of the same regions and it will allow the detailed study of the properties of giant molecular clouds in different environments: the nucleus of the galaxy, the bar regions, the ends of the bar, the inner rings. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2017-06-07T08:18:59.000 |
| 4278 | 2021.1.01050.S | 55 | A Closer Look at the Small Disks | A consensus is emerging from recent high resolution ALMA images that dust substructures are present in most disks. However, the unbiased 0.1" (~15 au) resolution disk survey of mm-sized dust in Taurus reveals two distinct groups of disks: some are large with gaps and rings, while others are compact and have smooth radial profiles. The large and the compact disks both have inner regions with similar brightnesses, so the lack of rings at large radii for the compact dust disks is not directly caused by sensitivity. We request two sets of observations for five compact disks (20-50 au radius) to test disk formation and evolution. First, we will use CO observations with 0.2" resolution to measure the gas disk size. Second, we will obtain continuum images with 0.03" resolution to detect any small-scale disk substructures. The size of the gas disk will indicate whether the disk was born small or whether radial drift of mm-sized grains is efficient. The presence of substructures at small radii would demonstrate that drift of mm-sized dust was halted by dust traps; the lack of substructures would indicate an absence of giant planets on scales comparable to our solar system. | Disks around low-mass stars | Disks and planet formation | 2023-07-25T19:14:43.000 |
| 4279 | 2015.1.00594.S | 2 | Unveiling the properties of a galaxy at the frontiers of the Universe | The Hubble Frontier Fields project is in an advanced observing stage and has delivered full datasets for three clusters. Our group has performed a systematic search for very high-z galaxies (z>6.5) in these three clusters yielding the discovery of dozen of extremely good candidates. Among all the very high-z candidates highlighted, some display a second magnitude break in the Spitzer data reinforcing the very high-z hypothesis. Spectroscopic observations with MMIRS/Magellan on the brightest z>7.5 object (F160W=25.90 AB) found behind Abell 2744, demonstrated that its redshift is z=8.34 through the detection of Lyman-alpha and CIV. The main goals of this proposal are (1) to confirm the spectroscopic redshift with the detection in band 7 of the FIR [OIII]88micron emission line as well as to estimate its metallicity and (2) to detect the continuum of this galaxy in order to constrain its properties, such as its Star Formation Rate, dust content and FIR luminosity. If we detect [OIII]88micron in this object it would be an exciting discovery making this object the most distant confirmed object observed with ALMA and could open a new way to study the first galaxies. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2017-10-20T20:47:53.000 |
| 4280 | 2018.1.01790.S | 43 | Quasar outflows at the highest redshifts | Feedback from QSOs is believed to play a key role in shaping the massive end of the galaxy population. Such feedback is probed by high-velocity wings on emission lines of CO or [CII], or by P-Cygni profiles on lines such as the OH 119 micron groundstate line. High-z QSOs are now readily probed using the [CII] line, but only a minority display line wings. Does this mean that most QSOs actually do not have outflows? We will carry out a pilot project doing a sensitive search for molecular outflows in the OH 119 micron line (ubiquitous in low-z dusty objects) in 3 dusty QSOs at z~6, so that the line is shifted into ALMA Band 7. This will reveal the ubiquity of OH-detectable outflows in z~6 QSOs, allow a derivation of key outflow parameters (mass outflow rate, momentum flux, terminal velocity), and inform a future more conprehensive proposal. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2020-07-12T15:31:47.000 |
| 4281 | 2015.1.00190.S | 29 | Getting to the bottom of the Toby Jug - Mapping the bipolar reflection nebula IC2220 | IC2220 is an extended (10' x 5') bipolar reflection nebula surrounding the M-type giant HR3126. The evolutionary state of this star is unclear; it may be an RGB, AGB or post-AGB object. It exhibits a high Li abundance, which may be due to an earlier period of increased mass loss. IC2220 was previously mapped by us via single dish CO observations. The CO emission outlines a hollow, expanding cylinder about 3'x3' in size. CO emission is also observed from an extended feature that may be the remnant of a disk that shaped the cylinder. Modeling indicates a total nebular mass of ~0.4 Msun, a radial velocity field, a low CO excitation temperature (3.6K) and a dynamical age of 4800yr. It has also been suggested, however, that some of the apparent complexity may simply be attributed to selective illumination. We propose to map the central region of IC2220 in CO(1-0), CO(3-2) and continuum with ALMA to establish the detailed structure of the nebula. This will enable us to understand its general nature, mass loss history, the mechanisms that shaped the outflow and its evolutionary status. We also aim to detect molecular species that could serve as alternative dynamical tracers. | Post-AGB stars, Evolved stars - Chemistry | Stars and stellar evolution | 2017-12-22T00:00:00.000 |
| 4282 | 2022.1.01739.S | 44 | Molecular gas content and feedback in the most luminous QSO2s at 0.55 < z < 0.85 | Molecular gas outflows have been argued to be among the most powerful manifestations of luminous Active Galactic Nuclei (AGN) feedback. In order to constrain this feedback, we propose ALMA 12m CO(2-1) observations of a sample of 10 QSO2s selected to be among the most luminous of such objects. Their bolometric luminosities log(Lbol) > 46 [erg/s] are close to those of quasars at cosmic noon when their feedback on host galaxies should be the strongest in cosmic history. With 0.55 < z < 0.85, we will sample 1-2 kpc scales at the hosts, expected to allow resolving luminous AGN outflows. Our goal is to measure the CO(2-1) flux distributions as well as the CO kinematics in order to: (1) obtain the total cold molecular gas masses M(mol); (2) obtain the ratio of M(mol) to the total stellar mass, verifying if this fraction differs from less luminous QSOs (which do not show an impact in their molecular gas reservoirs); (3) investigate the relation between M(mol) and the molecular gas kinematics, the AGN luminosity and ionised gas kinematics (among other quantities); (4) map and measure signatures of outflows, calculating their power and the corresponding effect on the host galaxy. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2024-05-08T09:34:36.000 |
| 4283 | 2017.1.00940.S | 44 | Investigating the accumulation of solids in the MWC 758 young disk | One of the least understood steps in our current understanding of planet growth is the formation of planetesimals. According to theory, planetesimals form when self-gravity brings together vast ensembles of small particles that are concentrated in small disk regions by different possible mechanisms. We propose to map the spatial distribution of small dust particles in the disk around the MWC 758 young star, which has shown evidence for dust accumulation from previous ALMA observations at relatively coarse angular resolution. We request the best possible angular resolution available in Cycle 5 to probe dust clumps on scales down to 3 au, as predicted by models of dust concentration. The requested ALMA Cycle 5 observations will be an important benchmark for any model of dust accumulation and planetesimal formation in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2018-11-29T18:49:04.000 |
| 4284 | 2018.1.01605.S | 42 | Resolved Kinematics of a Normal, Star-forming Galaxy at z=5 | What are the kinematic properties of normal, star-forming galaxies at z~5? In the high-z universe between z~1-3 IFU surveys have obtained resolved kinematics of hundreds of main-sequence galaxies. At z>4, however, our knowledge of the dynamical properties of typical, star-forming galaxies is scarce. To remedy this situation we propose to obtain spatially resolved kinematics of a normal, star-forming galaxy at z=5.5 based on Band 7 observations of the [CII] 158 um line. The latter represents an exciting new probe of the kinematics of high-z galaxies: it is one of the brightest emission line in galaxies (and remains bright in low metallicity environments), and its emission commonly extends beyond the point where star formation has ceased. Our target galaxy has been carefully selected to represent the properties of typical star-forming galaxies at z~5, and also due to its wealth of ancillary data including a [CII] ALMA detection. Our project will provide first of their kind measurements for typical star-forming galaxies at z~5, including rotation curves, diagnostics of disk stability, and constraints on the structure and baryonic mass fraction of the disk. | Galaxy structure & evolution | Galaxy evolution | 2020-09-30T00:00:00.000 |
| 4285 | 2012.1.00056.S | 0 | Hydrides in absorption at z=0.89 toward PKS 1830-211 | The z=0.89 molecular absorber toward the quasar PKS 1830-211 is the best, and perhaps only, source for obtaining very detailed information on the physical and chemical state of the molecular gas in the disk of a galaxy with a look-back time of half the age of the Universe. In ALMA Cycle 0, we have focussed on the strong absorption lines of most common interstellar molecules. Now, we propose to continue our exploration of the molecular inventory by focussing on hydrides, the key molecules at the root of the interstellar gas-phase chemistry and excellent diagnostics of the physico-chemical gas properties, and observe their ground-state transitions, otherwise difficult to observe or even inaccessible from the ground at z=0. | Gravitational lenses | Cosmology | 2015-06-23T21:21:38.000 |
| 4286 | 2015.1.00575.S | 11 | Submillimeter galaxies in high redshift cluste XCSJ2215 | We propose to measure the continnum and CO line fluxes for the galaxies at the center of cluster XCSJ2216 at z=1.46. The four first priority sources within 0.25Mpc radius of the cluster are detected in the SCUBA-2 850um map, and their counterparts in MIPS 24um maps are confirmed cluster members. We attempt to examine the dynamics, the molecular gas mass, the star formation efficiency, and the dust to gas ratio of these cluster galaxies from the CO(2-1) line observation. In addition, the continnum observation at band 6 is used to resolve the multiplicity issue, and to detect less star-forming galaxies indicated from the [OII] emissions. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2017-08-09T11:16:59.000 |
| 4287 | 2011.0.00003.SV | 0 | Science verification observation of Antennae galaxies | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Merging and interacting galaxies, Starbursts, star formation | Galaxy evolution | 2016-06-24T14:02:06.000 |
| 4288 | 2021.1.00889.V | 0 | Delving Deeper into PKS 1510-089 | We propose using phased ALMA as part of the Event Horizon Telescope (EHT) to image the polarized emission emanating from the gamma-ray bright blazar PKS 1510-089 in an effort to discern whether the jet is magnetically disordered or ordered on the micro arcsecond scales probed by VLBI at 1 mm. PKS 1510-089, along with a number of other blazars, has exhibited prominent orphan gamma-ray flaring behavior that can be explained by disordered turbulence in the jet spine or inverse-Compton scattering of photons emanating from regions of ordered magnetic field in the jet sheath. Determining the nature of the magnetic field within PKS 1510-089 using the high resolution (and sensitivity) afforded by a phased ALMA in concert with the EHT will help discriminate between models of blazar emission that have been developed to explain this high-energy variability. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-08-05T19:07:16.000 |
| 4289 | 2013.1.00432.S | 31 | A 3mm Line Survey of IRC+10216 : The chemical view of a C-rich object | IRC+10216 is a carbon rich evolved star in which more than 50% of molecules known in space have been detected. While a few diatomic and triatomic molecules are formed in the innermost regions of the circumstellar envelope, long carbon-chain radicals, metal-bearing cyanides, and other complex molecules are formed in an external ring, 14" in radius, where chemistry is dominated by UV photons and reactions between radicals and neutral species. Recent ALMA cycle0 observations at 270 GHz (Cernicharo et al., 2013) have shown the presence of hundreds of unidentified and intense lines arising from the dust formation zone. The carriers of these lines are certainly participating in the nucleation and growth of dust grains. We propose to carry out a sensitive line survey at 3mm with the following goals : 1) To fully characterize the molecular composition of the dust formation zone. 2) To fully characterize from several transitions of C4H, C5H, C6H, C7H, and their anions, the physical and chemical composition of the molecular ring where these species are formed. 3) To study the spatial distribution of the gas from the innermost regions (0.4") to the external chemically rich ring at r=14". | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2016-12-22T21:43:37.000 |
| 4290 | 2016.1.01533.S | 55 | Spatially Extended Continuum and Line Emission for the 30 Doradus Star Forming Region | The high angular resolution and sensitivity of ALMA makes it possible to study the core mass function in our nearest neighbors, the Magellanic Clouds, with similar mass sensitivity and spatial resolution as is obtained for molecular clouds with single dish telescopes in our own Galaxy. We are carrying out an archival project with ALMA to study the core mass function using continuum (and eventually spectral line) observations of star forming regions in the LMC. Here we are proposing for ACA stand-alone observations in Bands 3 and 6 of the 30 Doradus region. Combining these new data with similar data obtained in Cycle 0 will remove the significant negative bowls in the existing maps and result in maps of 30 Doradus of similar quality to those obtained of other regions of the LMC in later ALMA cycles. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2019-10-08T00:00:00.000 |
| 4291 | 2013.1.00885.S | 3 | Resolving Conversion Factor Variations in the Center of NGC 3351 | We propose to measure giant molecular cloud masses in the center of nearby galaxy NGC 3351 using optically thin C18O emission and an excitation temperature determined self-consistently from the ratio of the C18O (2-1) and (3-2) lines. These observations will provide robust measurements of GMC masses, free from important systematic effects that typically interfere with deriving masses from optically thin CO lines. We will use these masses and 12CO (1-0) observations to measure the CO-to-H2 conversion factor (alpha_CO) for each cloud. NGC 3351 has a very low average alpha_CO in its central ~kpc as measured using dust as a tracer for total gas. With these ALMA measurements we will take the first key steps towards understanding the physical cause of alpha_CO variations---a particularly crucial issue to address now that ALMA has made CO observable across a wide range of extragalactic environments. | Galactic centres/nuclei, Giant Molecular Clouds (GMC) properties | Active galaxies | 2016-03-11T14:00:16.000 |
| 4292 | 2015.1.01191.S | 37 | A new molecular gas mass tracer in galaxies: a first test in the local Universe | The fine structure lines of atomic carbon, [CI], stand out as the best alternative tracer of molecular gas in galaxies other than CO, because they have suitable range of critical densities, excitation temperatures, small optical depths, while the CI abundance is highly increased under the influence of strong cosmic rays (CR) due to the destruction of CO. However, they must be benchmarked locally against the widely used low-J CO transitions as global molecular gas tracers. We propose to image [CI] 1-0 and CO J=1-0 (with CN N=1--0 as bonus transitions) in three local luminous infrared galaxies, drawn from a population of dusty and vigorously star-forming galaxies, as good analogues of high-z sub-mm galaxies.This allows a sensitive assessment of the relative H2-tracing capabilities of [CI] 1-0, CO 1-0, and submm dust on 250 pc scales, and a search for the predicted CR-induced CO-destruction. The proposed study will open a new window to better determine molecular gas mass in galaxies, near and far. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2017-09-27T11:59:35.000 |
| 4293 | 2023.1.01100.S | 0 | Hunting two planet candidates from gas and dust signatures | How, where, and when planets form in protoplanetary disk is still under debate. Recently, direct evidence of planets has been found around class II disks at infrared wavelenghts (direct imaging) and millimeter observations (CPDs and kinematic signatures). However, the number of disks where planets have been hunted (and their properties constrained) is still limited due to low SNR and/or low spectral resolution observations. Here we propose to observe the disk around the star 2MASS J16120668-3010270, where previous band 6 observations have revealed a kinematic signature in the outer disk, and SPHERE observations have found a point-source localized in the gap of the dust continuum emission, making this source a great opportunity to hunt planet candidates. We request band 7 observations of 12CO and 13CO (J:3-2) at an angular resolution of 89 mas and a spectral resolution of 0.025 km/s, which will be used to confirm kinematic signatures, study planet formation in the inner and outer disk, and constrain the properties of the point-source. The proposed observations will significantly increase our understanding about the potential correlation of the gas and planet candidate properties. | Disks around low-mass stars | Disks and planet formation | 2025-07-30T22:25:00.000 |
| 4294 | 2024.1.01508.S | 0 | Revealing the vertical structure of molecular gas in a nearby Milky Way analog | We propose to survey CO(2-1) emission across the star-forming disk of the nearby (D = 3.6 Mpc), massive, highly inclined galaxy NGC 4945, revealing the vertical structure and distribution of molecular gas at 10 pc resolution for the first time. We will use these observations to test theoretical predictions about the in-plane concentration of filaments and search for vertically-extended structures such as large-scale filaments and oscillating gas density waves. We will combine these data with complementary MUSE and ACA dense gas observations to determine diagnostic line ratios and measure the resolved scale height across different phases of the ISM. By accessing the vertical dimension, these observations will validate key theories of pressure-regulated star formation and help constrain models of star formation, stellar feedback, and their influence on and relation to the vertical compression of the interstellar medium. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 4295 | 2019.1.01750.S | 29 | The first observation of coronal radio emission from narrow-line Seyfert 1 galaxies | We challenge to detect the synchrotron radio emission from coronae above accretion disks in narrow-line Seyfert 1 galaxies (NLS1s) for the first time. Although the coronal emission of AGNs had never been detected in radio wavelengths, we have successfully detected the nonthermal component of AGN coronal radio emission for the first time by our previous ALMA observations (Cycle 4) of Type-1 Seyfert galaxies, IC 4329A and NGC 985 with relatively low accretion rates. As a next step, we unveil the nature of the coronae in the NLS1 class with high accretion rates for the first time, by simple point-source photometry at Band 3, 4, and 6. Why do we need ALMA?: Coronal radio emission is expected to show a continuum spectrum peaked at millimeter wavelengths due to strong synchrotron self-absorption. Based on the radio/X-ray flux ratio, expected flux densities are a few mJy levels even for the brightest three NLS1s. To avoid dust contamination, high angular resolutions are required. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-05-12T00:00:00.000 |
| 4296 | 2019.1.00618.S | 34 | Resolving the molecular tori and nuclear outflows in the most luminous Seyferts in the local Universe | This proposal addresses the fundamental question of the obscuring material and gas flow cycle in AGN. We aim for the most luminous Seyferts at distances<40Mpc to connect with those AGN driving feedback on cosmological scales. It is only with ALMA that we can resolve both the obscuring molecular torus and AGN-driven nuclear molecular outflows. We propose Band 7 observations of the CO(3-2) and the HCO+(4-3) lines and associated continuum at 9-11pc resolution. We will test the prediction that molecular tori of luminous Seyferts are larger and with smaller covering factors than in less luminous AGN, possibly due to the role of AGN-driven outflows in clearing some or even all the obscuring material around the accreting supermassive black hole. With the proposed observations we will bridge the gap with our existing samples of low luminosity AGN observed at similar physical resolution and luminous quasars. Our final goal is to provide a holistic picture of the molecular tori and nuclear outflows for a large range of AGN bolometric luminosities, obscuration, and Eddington ratios with the required physical resolutions (<=11pc) to resolve these regions. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2022-07-28T10:46:04.000 |
| 4297 | 2013.1.00188.S | 9 | A detailed study of infrared radiative pumping in a nearby bright pure AGN | We propose HCN/HCO+/HNC observations at vibrationally-excited and -ground levels, of the nearby bright AGN-dominated nucleus of NGC 1068. Our scientific goal is to estimate the strengths of vibrationally-excited emission lines of HCN/HCO+/HNC, and to clarify whether infrared radiative pumping indeed selectively boosts HCN emission, when compared to HCO+ and HNC. Detailed study of this prototypical pure AGN will play a crucial role to resolve the highly disputed issue of whether infrared radiative pumping is indeed important to enhance HCN emission in many AGNs. If the infrared radaitive pumping is ubiquitously at work for HCN excitation in AGNs, vibrationally excited HCN emission lines must be clearly detected in the NGC 1068 nucleus with ALMA. If these lines are not detected, ubiquitous role of infrared radiative pumping for enhanced HCN emission in AGNs is strongly ruled out. ALMA's high-spatial-resolution (<0.6 arcsec) is vital to probe only the AGN-dominated nuclear region, with minimum contamination from surrounding starburst activity in the host galaxy. ALMA's high-sensitivity (sub-mJy noise level) is indispensable to clearly distinguish between contradictory scenarios. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2016-07-22T22:24:21.000 |
| 4298 | 2019.1.00927.S | 81 | Constraining the dust-to-gas mass ratio in planet-forming disks | The dust-to-gas mass ratio in young (1-10 Myr) circumstellar disks is a key quantity as it regulates what planets can form and how long disks survive. Yet, it remains poorly constrained. The finding that many such disks have weaker than expected CO emission has recently led to two main hypothesis: A) significant disk gas has been dispersed, hence the dust-to-gas mass ratio is much larger than the ISM value or B) the dust-to-gas mass ratio is still close to the ISM value but CO is not a good tracer of the gas mass. We propose to use the ACA to detect atomic carbon via the [CI] 1-0 line at 492GHz and discriminate between these two hypothesis. Atomic carbon traces the surface of circumstellar disks and its amount is rather insensitive to the gas density, temperature, and UV flux while being very sensitive to the dust-to-gas mass ratio. With a disk sample covering more than an order of magnitude in dust disk masses, we expect to find an anti-correlation between dust disk mass and CI emission if scenario A is correct, no correlation for scenario B. These observations will form the basis for future observations to characterize the spatial extent and kinematics of atomic carbon. | Disks around low-mass stars | Disks and planet formation | 2022-11-09T21:08:22.000 |
| 4299 | 2011.0.00429.S | 0 | How to make massive protostellar cores? | Massive stars (>8 Msun) are at least one order of magnitude more massive than the Jeans mass of the molecular clouds in which they are born. This creates a theoretical puzzle since cores significantly larger than the Jeans mass are unstable against fragmentation to less massive objects. Several ideas have been proposed to suppress fragmentation to favor the formation of massive cores, ranging from turbulence injection from protostellar outflows of low-mass stars in the cluster, to an enhanced temperature due to heating from accreting low-mass stars. On the other hand, it has also been suggested that massive stars may form from Jeans-mass cores that accrete most of their mass from the general environment. We have carried out an observational program aimed at testing these ideas using the existing interferometers. The study yields promising clues to the formation of massive stars. During the ALMA early science, we propose to follow-up a massive molecular clump IRDC G28.34 using ALMA Band 6 and the extended configuration. The order of magnitude increase in dust continuum and spectral line sensitivity over our SMA observations will for the first time reveal kinematic and thermodynamic properties of massive dust cores, and test the scenario of protostellar heating and protostellar outflows in aiding massive core formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2014-02-21T22:03:00.000 |
| 4300 | 2018.1.00564.S | 288 | Completing the Census of Disks in the Upper Sco OB Association | The Upper Scorpius OB Association plays a central role in establishing the evolutionary history of circumstellar disks. As the closest OB association and at an advanced age of 11 Myr, it is the benchmark region in which to establish the disk properties at the end stage of disk evolution. In the past few years, members of our team led an optical and near-infrared spectroscopic campaign to identify new members of Upper Sco that expanded the disk population to 260 stars with spectral types between G0 and M5, which nearly triples the number of previously known disks in Upper Sco. We propose to complete the ALMA census of Upper Sco by surveying the newly identified disks in the dust continuum and CO J=3-2. The full survey is anticipated to yield 140 continuum detections and 65 CO detections, which will provide an unprecedented census of the final stages of disk evolution. Our specific goal is to determine if dust depletes faster around low-mass stars as suggested by recent studies. More broadly, by tripling the number of disks in Upper Sco with ALMA measurements, this survey will provide a lasting resource for disk evolution studies. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2020-08-18T02:28:31.000 |
| 4301 | 2023.1.01379.S | 0 | Is accretion in planet-forming disks governed by magnetic winds? | The fundamental mechanism governing disk evolution remains debated, limiting our understanding of planet formation. The long standing paradigm of viscous evolution is now challenged and the emerging paradigm proposes that disk accretion and dispersal is driven by the launching of magnetized winds from the disk. Still, only a handful of molecular outflows have been mapped in Class II sources at sufficiently high surface brightness sensitivity, bringing strong but sparse evidence for MHD disk winds. The time is ripe to determine if MHD disk winds are ubiquitous in Class II disks or if they are the exception. We propose to map at high sensitivity (0.56 K in a 0.3 km/s channel) and good angular resolution (0.4"~75 au) the 12CO(2-1) emission in 10 actively accreting Class II sources in Chamaeleon I, searching for rotating outflows. This pilot survey will constitute the first discriminant test of the newly proposed paradigm of MHD disk winds. If present, the impact of MHD disk winds on disk evolution and planet formation will be further quantified by inferring the wind mass-loss rate, the launching region, and the angular momentum extracted by the wind. | Disks around low-mass stars | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 4302 | 2013.1.01075.S | 52 | Protoplanetary Disk Evolution in Spatially Resolved Pre-Main Sequence Binaries: Chamaeleon I | Stars frequently form in binary systems. Our observational knowledge about the evolution of protoplanetary disks in binary stars, however, currently leaves many questions unanswered. For example, while theory predicts how the sizes of circumstellar disks are truncated in the presence of a binary companion, an observational confirmation is still required and the impact of truncation on the evolution of the inner disks is unknown. We propose to acquire high-angular resolution band 7 continuum observations of 26 binary stars in the Chamaeleon I star-forming region. The inferred disk masses and sizes will be correlated with stellar and binary parameters from our extensive near-IR binary investigations of the target sample. This is the first study dedicated to measuring the correlation of hot inner disk material and cold outer dust around binary star components to investigate whether the evolution of a truncated binary star disk is significantly different from that of singles. It will triple the current amount of data to observationally test the theoretically predicted truncation radii of disks in binaries, with many applications in the fields of star and planet formation. | Disks around low-mass stars | Disks and planet formation | 2016-10-19T06:59:38.000 |
| 4303 | 2018.1.01190.S | 36 | Chemistry in extremely FUV illuminated protoplanetary disks | Most Solar-type stars form in clusters where the radiation field can be enhanced by several orders of magnitude relative to isolated stars. Just as the chemistry in the interstellar medium is modified in the presence of high mass stars, heavily irradiated protoplanetary disks should be affected as well. Currently, we have no observational constraints on how this affects the disk chemistry compared to our typical isolated disk targets. To address this unknown, we propose to carry-out a chemical survey of four disks in the massive star forming region of Orion. The sources are selected based on recent ALMA observations. The sample includes disks with clear molecular line emission and span a range of distances from the ionizing stars in the cluster. We will target the same tracers that have been used to characterize the chemistry in isolated disks: CO isotopologues, HCN, DCN, H2CO, C2H and C3H2. This will allow a direct comparison to assess what is the impact of strong FUV radiation on the disk chemistry. | Disks around low-mass stars | Disks and planet formation | 2020-12-12T17:22:00.000 |
| 4304 | 2013.1.00055.S | 6 | The footprints of SF and AGN activity in NGC1068 (II) | We propose to map the emission of a set of dense molecular gas tracers (CO(6-5), HCN(1-0), HCO+(1-0) and CS(2-1)) in NGC1068 using the unique spatial resolution (0.1"-0.5") and sensitivity of ALMA. The science case of this project builds on the results of our successful Cycle 0 project. These data have revealed that the kinematics of the molecular gas in the circumnuclear disk (CND) are driven by an AGN-powered outflow from r~50pc to r~300pc. The new 12CO(6-5) maps proposed in this follow-up will offer an unprecedented view of the gas flows in the central r~35pc of NGC1068 with a spatial resolution of ~a few pc. This will allow us to study the expected signature of gas inflow closer to the central engine and to spatially resolve the emission of the torus. We also propose to map the emission of HCN(1-0), HCO+(1-0) and CS(2-1) with a 0.5"(35 pc) spatial resolution in a larger area that extends out to the starburst ring. The new maps will be combined with the Cycle 0 maps obtained for the mid-J transitions of the same species, a crucial step to characterize the changes in the excitation and chemistry of the dense molecular gas on critical scales in and around the CND. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-10-16T21:25:58.000 |
| 4305 | 2023.A.00003.S | 49 | [OIII] Confirmation for Intrinsically Luminous z~12 Galaxy Candidates that Test Early Stellar Mass Assembly | Spectroscopic confirmation of the brightest, highest-z galaxies is needed to constrain galaxy formation models and the assembly of the first massive halos formed after the Big Bang. We have identified three luminous (MUV~-22), robust candidate z~12 galaxies from wide-field JWST imaging. They are a magnitude brighter than galaxies already identified to be unusually bright systems (like GNz11) and likely to be among the brightest z~12 candidates JWST ever finds. All three are in mild 2sigma tension with expectation on mass within LCDM, so confirming one of three would be extraordinary, and all three would be game-changing. Given their luminosity and spatial distribution, ALMA is uniquely suited to provide the most efficient means of spectroscopic confirmation. We propose [OIII] spectral scans in band 6 covering redshifts 11.4 | Lyman Break Galaxies (LBG) | Galaxy evolution | 2024-07-02T15:10:36.000 |
| 4306 | 2016.1.00568.S | 17 | Breaking the Low Metallicity Limit for CO Detections | Dwarf starburst galaxies have high star formation rates, which implies that they should be rich in molecular gas. However, the most common tracer of bulk molecular gas -- CO -- is faint in these and other low metallicity systems. The likely explanation for this trend is that that increases in the CO-to-H2 conversion factor are driving increases in SFR/LCO with metallicity. To date, this hypothesis has yet to be tested below a metallicity of 0.1 solar because of the limited sensitivity of existing telescopes. We propose to use ALMA to detect or place strong upper limits on the CO emission in three dwarf starbursts with metallicities between 0.2 and 0.06 solar to test the hypothesis that the SFR/LCO ratio follows a linear (in log-log space) trend with metallicity, which is the simplest trend consistent with existing data. The proposed observations will also detect the 870micron continuum. We will use these data, along with in-hand VLA centimeter continuum data, to measure the dust mass and place constraints on the CO-to-H2 conversion factor. Ultimately, these data will provide some of the first stringent constraints on the CO-to-H2 conversion factor at metallicities below 0.1 solar. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2018-03-31T22:29:18.000 |
| 4307 | 2012.1.01092.S | 2 | High Resolution Imaging of the Silhouette Disk in Powerful Radio Galaxy 3C 31 | We propose ALMA high sensitivity observations of CO(J=3-2) and (J=2-1) emissions form the silhouette disk in the powerful FR-I radio galaxy 3C 31, that achieve the high angular resolution of 0.5 arcsec. Okuda et al. (2005) found that the distribution of CO gas in 3C 31 is a ring-like shape with a radius of 3 arcsec, and that the circular rotating neutral/ionized gas disk closely coincides with the silhouette disk seen by the HST. The molecular gas distribution in the outer disk in 3C 31 was clearly seen in Okuda et al. (2005) at the spatial resolution of 1.9 arcsec x 1.4 arcsec corresponding to 640 pc x 470 pc at a distance of 3C 31 (70 Mpc). However, the variation of the ISM distribution from the nucleus to the circumnuclear disk has not been derived so far. If non-circular motion like weak components seen in Okuda et al. (2005) is detected reliably, it will be a clue to reveal the fueling mechanism from the circumnuclear region to the nucleus and the relation between the silhouette disks and the activities of the AGNs. From the obtained spatial distributions of CO(J=3-2) and (J=2-1) obtained with the ALMA by more adding CO(J=1-0) by the NoMA and the RAINBOW interferometer, we will be able to investigate the physical conditions of the molecular gas in the silhouette disk of 3C 31. The Xco factor can be obtained from the molecular gas mass derived by Large-Velocity-Gradient (LVG) model and then the exact amount of molecular gas can be estimated. There is a possibility that Xco factor in 3C 31 may drastically change across the molecular disk, because an active nucleus exists in the center of this object and also the physical properties of molecular excitation will significantly be changed due to strong UV radiation and X-ray radiation from the nucleus. These combined observation results also will provide us with crucial information on the physical properties (the excitation temperature, in particular) of a circumnucler disk at the center of a powerful radio galaxy. | Active Galactic Nuclei (AGN)/Quasars (QSO), Early-type galaxies | Active galaxies | 2016-11-18T04:16:48.000 |
| 4308 | 2017.1.01226.S | 27 | Dust destruction by radio jets in Seyfert galaxies as seen by ALMA and VLT | Shocks are the source of great disturbance in the interstellar medium (ISM) playing an important role in the understanding of feedback in the context of galaxy evolution. Our goal in this proposal is to trace the destruction of dust grains along and away from radio jets in a sample of 2 Seyfert-2 galaxies by using shock tracers in the mm-waves. We will compare the abundance of species sputtered from grain cores (eg. Si) to study the extension and impact of shock waves in the ISM. We will use the unique spatial and spectral capabilities of ALMA Band 4 spectroscopy to detect SiO and HNCO, mapping the spatial distribution of dust destruction associated to the SiO abundance. Additionally, we want to investigate the kinematic structure of shocked gas from ALMA with the destruction of dust grains. Finally, we will contrast these results with an independent shock dianostic in the near-IR ([FeII]/[PII])obtained from VLT data in hand. | Outflows, jets, feedback | Active galaxies | 2019-03-18T14:12:49.000 |
| 4309 | 2021.2.00030.S | 56 | Investigating the CI/CO Abundance Ratio of Shock-Excited Gas in the Magellanic Supernova Remnant N63A | Atomic carbon line emission (CI) is thought to be a good tracer for deducing the H2 distribution in galaxies and one that can be as reliable as low-J CO line emission. However, it is not fully understood how the CI/CO abundance ratio is modified under the environment where cosmic-ray induced and/or shock destructions of CO molecules occur efficiently. We propose to observe CI(3P1-3P0) and CO(J = 3-2) line emission toward the pre- and post-shocked molecular clouds in the Magellanic supernova remnant (SNR) N63A which provides one of the best laboratories to measure the variation of CI/CO abundance ratios through cosmic-ray induced and/or shock destructions of CO without any contamination along the line of sight. In particular, the high CI/CO abundance ratios due to the shock-destruction of CO can be seen only in the post-shocked layer, whereas cosmic-ray induced destructions will affect the whole of the pre- and post-shocked clouds owing to their energy-dependent diffusions. ALMA is the only telescope array that can study the shock and cosmic ray induced astrochemistry with sufficient angular resolution and sensitivity. | Astrochemistry, Magellanic Clouds | ISM and star formation | 2023-12-21T20:09:13.000 |
| 4310 | 2012.1.00712.S | 0 | Pre-biotic molecules in low-mass protostars | Glycolaldehyde is the simplest sugar and an important intermediate in the path toward forming more complex biologically relevant molecules. In ALMA science verification observations of the deeply embedded, Class 0, low-mass protostellar binary IRAS 16293-2422 we have detected 13 transitions of glycolaldehyde distributed over band 6 and 9. The glycolaldehyde emission has its origin in warm (200-300 K) gas close to the individual components of the binary (Jorgensen et al. 2012, submitted to ApJ Letters). The detections, however, suffer from somewhat uncertain line frequencies extrapolated from laboratory measurements at lower frequencies. With this ALMA Cycle 1 proposal we first aim to seal the assignment by targeting a set of band 3 lines with frequencies measured in the laboratory. Secondly, the potential discovery of glycolaldehyde in this solar-type star raises new questions concerning how such complex organic molecules are formed in the gas and dust during the star formation process. We will address these questions by measuring the relative abundances of the full inventory of oxygen-bearing complex organic species involved in the standard networks for formation of glycolaldehyde. The abundances will be measured homogeneously and on similar scales thereby providing strong constraint on the main routes for formation of these species including for example the importance of the initial ice composition and the importance of UV. This will be done through imaging of the species on 0.6" scales (inner 35 AU regions around the protostar) also making it possible to directly measure any spatial correlations between the species related to their underlying chemistry. | Low-mass star formation, Astrochemistry | ISM and star formation | 2015-07-30T18:39:15.000 |
| 4311 | 2021.A.00026.S | 19 | Clarifying onset of strong binary interaction in SN 2018ivc 1000 years before its demise | A supernova (SN) provides a unique probe to the still-unresolved evolution of massive stars in the final ~1000 years. We propose a DDT observation of SN 2018ivc in Bands 3 and 6, at ~1400 days since the explosion (Aug-Sep 2022). SN 2018ivc was detected by ALMA from 4 days to ~200 days after the SN explosion, showing a usual decay. Just recently, it has been noticed that the SN started rebrightening somewhere between 200 and 1000 days, which was found by inspecting ALMA data taken at ~ 1000 days (which targeted the host, covering the SN serendipitously). Such rebrightening is unprecedented, known only for a few SNe in cm wavelengths, but not in mm. The timing corresponds to ~1000 years before the SN, which matches to the onset of strong binary interaction scenario for this SN. The proposed observation will for the first time tell us about what happens at the onset of strong binary interaction, which has never been identified observationally. The proposed observation will thus provide a milestone to understand the final evolution of a massive star especially in the context of the binary evolution scenario, which is relevant to the majority, if not all, of massive stars. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2023-03-02T07:11:03.000 |
| 4312 | 2011.0.00034.S | 0 | CO in the Ultraluminous Galaxy IRAS F00183-7111 | We propose to observe the CO(1-0) transition at 3mm in the extreme ULIRG F00183-7111, which has been caught with a radio-loud AGN in its centre, representing an extreme example of the class of radio-loud AGNs buried within dusty star-forming galaxies. This source appears to be a rare example of a ULIRG glimpsed in the brief period as it changes from “quasar mode” to “radio mode” activity. We have already detected the CO signal from this galaxy with the ATCA, and here propose to start a program of studies of the CO to pin down the dynamics and star formation processes in this object, to test models of the evolution of ULIRGs. | Starbursts, star formation, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2014-05-06T14:50:00.000 |
| 4313 | 2015.1.00597.S | 3 | Weighing Low Mass Black Holes in the Nearest AGN | We propose to use ALMA to make the first robust dynamical detections of ~10^5 solar mass central black holes in two nearby galaxies. These measurements will provide constraints on the formation of black holes in the early universe, and on the physics underlying galaxy -- black hole scaling relationships. Our targets are two active galactic nuclei (AGN) at D < 5 Mpc, and both show clear evidence from near-infrared observations of rotating molecular disks surrounding their black holes. The high resolution of ALMA will enable us to significantly improve on existing black hole mass measurements of these galaxies. | Galactic centres/nuclei, Dwarf/metal-poor galaxies | Active galaxies | 2017-02-12T22:09:32.000 |
| 4314 | 2012.1.00182.S | 8 | Examining the effects of the T Cha planet on its birthsite transitional disk | Our understanding of exoplanet formations processes has been hampered by the difficulty of detecting young forming planets still in their natal disks. T Cha was discovered to have a transitional disk with an inner dust hole based on Spitzer spectroscopy. Recent L and K band imaging has detected a potential planet within the hole, making the T Cha transitional disk a rare opportunity to directly test theories of planet formation and disk clearing. We propose to use the high spatial resolution and sensitivity of ALMA to image T Cha in the most extended configuration at band 7 to spatially resolve and characterize the inner hole in both dust and gas. We will determine the cavity size and compare with the planetary dynamics to test theories of planetary disk clearing through gap formation. Searching for gas tracers from within the hole will allow us to look for signs of mass flow across the planetary gap. To date, T Cha is one of only two disks with a known forming planet and thus a pivotal laboratory to directly test models of planet formation. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2016-09-01T23:15:35.000 |
| 4315 | 2017.1.00938.S | 20 | Complex Organics in Solar Nebula Analogs | The ubiquity of complex organic molecules (COMs) in disks determines the typical pre-biotic potential of nascent planetary systems. Observations of protostellar cores and comets have long shown that disks are bookended by a wealth of chemical complexity. In disks, however, prevalent freeze-out of volatiles and small angular scales kept COMs hidden until the advent of ALMA. In separate C2 programs we detected CH3CN in the disk of V4046 Sgr and CH3OH in TW Hya, providing clear evidence for the presence of N and O-bearing COMs in these old, nearby Solar Nebula analogs. To provide first constraints on the relationship between N- and O-bearing COMs during planet formation we now request the complementary observations, i.e. CH3OH toward V4046 Sgr and CH3CN toward TW Hya. The two nearby, iconic disks have among the best constrained physical and chemical structures, making them optimal for both detecting and characterizing trace species. The resulting observations will provide a key first constraint on whether the ratios of different COM families are consistent across Solar Nebula analogs, and between such analogs and remnants of the Solar Nebula itself, i.e. comets. | Disks around low-mass stars | Disks and planet formation | 2019-05-29T14:26:01.000 |
| 4316 | 2022.1.00141.S | 9 | Cloud-Scale Dust Continuum Imaging of an Early-Type Galaxy | The cold molecular hydrogen content of a galaxy has traditionally been traced through CO, along with a CO conversion factor, which varies significantly galaxy-to-galaxy. Here, we propose an alternative method to tracing this molecular gas, instead using the cold dust continuum at ~350GHz. We propose pilot observations of a single ETG, NGC4526. These observations will improve, by a factor of ~500, the resolution from earlier, single-dish studies, and we will: -Perform a cloud-scale calibration of the CO-conversion factor, which is currently unconstrained in ETGs. Given the resolution of our measurements, we will also have an additional constraint from cloud dynamics, so will be independently able to verify whether these clouds are virialised. -Perform a systematic search for CO-dark gas (molecular hydrogen not traced by CO). This will allow us to quantify the amount of molecular hydrogen missed by CO measurements, which can account for significant amount of the total molecular mass. -Investigate CO(3-2)/CO(2-1) line ratios in these clouds. This will allow insights into the conditions of the gas, probing environmental variation, and how this varies with the CO conversion factor. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-06-30T08:01:46.000 |
| 4317 | 2011.0.00768.S | 0 | Star formation rates enhanced by dynamical effects: the extreme starburst in NGC1614 | The star formation efficiency of the dense molecular gas in the LIRG NGC1614 is one of the highest ever measured. This may be related to its unusually short dynamical timescale. We propose Band 7 observations with the ALMA extended array to image the line emission of the dense gas tracers CO(3-2) and HCO+(4-3) in this extreme starburst. The acquired data will be combined with a multiwavelentgh data-set that includes HCN(1-0), HCO+(1-0), HNC(1-0), H-alpha and Pa-alpha images. We will assess the extent to which a high fraction of dense molecular gas and/or an unsettled dynamics enhance the star formation efficiency of (U)LIRG. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG), Starbursts, star formation | Galaxy evolution | 2013-10-15T11:43:39.000 |
| 4318 | 2015.1.01083.S | 42 | Planetary Formation in the late-phase of classical T Tauri stars located at CrA west | We propose to observe two classical T Tauri stars just before accretion ceases, to understand how dust grain size evolves in the circumstellar disk. Our two targets, RX J1842.9-3532 and RX J1852.3-3700, are early-K type classical T Tauri stars with dust disks located 130 pc from our sun. From our recent observations, the circumstellar disk of RX J1852.3-3700 was resolved into a gap-like structure and an asymmetric outer ring. Because our near-infrared scattered light image does not trace the real column density distribution, we propose to measure the sub-mm continuum to reveal 1) the spatial distribution of dust, and 2) its changing opacity due to the grain growth of dust. | Disks around low-mass stars | Disks and planet formation | 2018-04-17T00:00:00.000 |
| 4319 | 2015.1.00186.S | 183 | Protostellar Multiplicity in Isolation | Multiple star systems are a common outcome of star formation. While the binary frequencies and separation distributions are well-characterized in the field, theoretical studies predict that the majority of multiple systems are formed very early in the protostellar phase and undergo significant and rapid dynamical evolution. Thus knowledge of the intrinsic multiplicity fraction and separation distribution before modification via dynamical evolution requires studying the youngest objects: Class 0 and I protostars still embedded in and accreting from their parent cores. Recent surveys have made great progress in characterizing protostellar multiplicity in clustered environments but have left unanswered a key question: is the fragmentation into multiple systems dependent on environment? Here we propose an ALMA band 6 multiplicity survey of 22 truly isolated protostellar cores down to approximately 30 AU resolution in order to measure the protostellar multiplicity fraction and separation distribution in isolated globules and determine the effects of environment on fragmentation. | Low-mass star formation | ISM and star formation | 2018-03-03T19:27:56.000 |
| 4320 | 2019.1.01266.S | 57 | Mapping Jet-ISM Interactions in X-ray Binaries | Relativistic jets launched from accreting black holes carry large amounts of energy and matter into their environment. Black hole X-ray binaries (BHXBs), the stellar-mass analogues of active galactic nuclei, are ideal targets for studying the interactions between the jet and the ambient ISM in detail, due to their close proximity and the rapid timescale evolution of BHXB jets. Identifying and probing the ISM properties in interaction zones provides insight into highly sought-after jet properties, such as the jet power, composition, duty cycles, and the efficiency of jet feedback. As molecular lines are excellent diagnostics of shock energetics and ISM excitation, our team recently obtained ALMA ACA observations of the candidate interaction sites around the BHXBs GRS 1758-258 and 1E 1740.7-2942, identifying several intriguing compact regions of bright molecular emission. Here we propose follow-up, high resolution ALMA 12m array observations of these fields (total time of 2.3 hours). With these data we will build on our first results to test whether these zones are consistent with being powered by a BHXB jet, and estimate the energy input into the ISM from these BHXB jets. | Outflows, jets and ionized winds, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-03-26T14:43:57.000 |
| 4321 | 2012.1.00581.S | 0 | Molecular Oxygen in Intermediate Redshift Absorber, B1830-210 | Molecular oxygen has long been identified as a critical species for the understanding of cooling and energy balance in molecular clouds and of interstellar oxygen chemistry. However its abundance is famously much lower than predicted by standard astrochemical models, for reasons that remain unclear. Our goal in this proposal is to make use of ALMA's remarkable sensitivity to execute a deep search for molecular oxygen absorption in the ($1_{2}-3_{2}$) [424.7631GHz] transition toward the intermediate redshift ($z=0.886$) absorber B1830-210, to follow up our existing anomalously bright 56 GHz ($1_{2}-1_{1}$) detection. We will compare the results obtained from this transition with that of the 56 GHz transition to characterize radiative transfer and excitation models applicable to B1830-210. From this we will determine robust abundances and provide important constraints on molecular oxygen chemistry. | Astrochemistry | ISM and star formation | 2015-04-16T12:24:09.000 |
| 4322 | 2016.2.00058.S | 240 | Physical and chemical properties of cold Orion cores very close to the onset of star formation | The initial condition is a key for star formation studies. We have successfully identified two very attractive cores in the Orion GMC: one is a candidate of starless cores on the verge of star formation, and the other is a star forming core probably at the earliest stage. These core were detected in DNC and N2D+ with Nobeyama 45 m telescope in the follow-up observation to JCMT/SCUBA-2 legacy program SCOPE for Planck cold clumps. The N2D+ linewidth is as narrow as 0.45 km/s in both cores. We can assume that they are cores just before and after the onset of star formation in almost the same environment. We will investigate (A) Mechanism of the onset of star formation: turbulence dissipation or accretion?, (B) Core dynamics: infall or oscillation?, (C) Chemical evolution status within the cores. This observation tackles the basic question: how star formation starts? | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-05-14T00:00:00.000 |
| 4323 | 2018.1.01778.S | 10 | Mapping the Star Formation in SPT0311-58 | We request a deep, sub-kpc resolution map of the OIII 88um line emission from a unique system of dusty galaxies in the Epoch of Reionization (EoR). SPT0311-58 is a system of massive interacting galaxies at z=6.900 that was found via their millimeter-wavelength dust emission in the South Pole Telescope survey. In previous cycles we have shown these galaxies to reside in an extremely massive dark matter halo, reconstructed the spatial/velocity structure of the galaxy pair through a pixelated lens modeling technique, and measured their dust, gas, and stellar content. We now have <0.1"-resolution images of this system in both continuum and the 158um CII line, which show the two main galaxies to be composed of clumpy high-velocity-dispersion regions of star formation. We propose to augment these maps with the high-ionization OIII line, which should emit only in regions of active star formation and around accreting black holes. With OIII, CII, and continuum information we will explore the distribution of star formation in z~7 galaxies, trace the assembly history of these objects, and better understand the utility of the OIII line for future observations of even higher redshift galaxies. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-01-22T15:26:32.000 |
| 4324 | 2015.1.00503.S | 159 | Physical properties of CO dark molecular gas from multi-band absorption observations | The common, familiar tracer for molecular hydrogen (H2) is CO emission. However, H2 without CO emission, called "Dark Molecular Gas", turns out to be surprisingly abundant, roughly equal in mass to the more familiar CO-traced H2. Dark Molecular Gas represents the transition between the atomic ISM to the molecule-dominated ISM -- the initial stage of star formation, which lies at the very heart of modern astrophysics. To explore the conditions that lead to this transition, we propose a broad frontal attack on Dark molecular gas, consisting of (1) using ALMA to measure the lowest three rotational lines of HCO+ and CO in absorption against the strong mm-wave continuum source 3C454.3; (2) using ALMA to survey the J=1-0 lines of HCO+ and CO and HCN, HNC, and CN lines against 12 strong mm-wave continuum sources. In absorption, ALMA can accomplish in minutes what requires hours at CARMA, making such a systematic study feasible. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-10-05T02:12:42.000 |
| 4325 | 2019.1.01209.S | 9 | Initial environmental magnetic field and turbulent properties: does it matter to shape the outcome of star formation ? | Using ALMA data probing the kinematics and magnetic field, and their comparison to synthetic observations of MHD numerical simulations of protostellar formation, we showed that the isolated B335 protostar is prone to a magnetically-regulated collapse, where magnetic field shapes its disk size and small scale angular momentum properties. Now that we have established a successful analysis methodology for testing models of magnetically-regulated protostellar collapse, it is crucial to start testing whether this scenario is also at work in other solar-type protostars, and if this scenario develops only in specific environmental conditions. We now propose to test whether magnetic braking regulates the envelope kinematics, disk formation and fragmentation, this time targeting two strikingly similar protostars which share the same genetic heritage, the Taurus twins. Both protostars are embedded together in a simple environment, with similar large scale magnetic, and turbulent conditions: the comparison of the magnetic and kinematics structure in theses two twin cores can be used efficiently to constrain the conditions necessary for magnetically-regulated collapse to develop. | Low-mass star formation | ISM and star formation | 2021-03-20T00:00:00.000 |
| 4326 | 2023.1.00448.S | 0 | An ALMA CO survey of quasars at z~0.5: testing the compaction-driven black hole and galaxy growth model | Observations of the nearby universe find that the mass of supermassive black holes (BHs; MBH) is closely linked to the mass of classical bulges (Mbulge). However, in the distant universe, the bulge mass of luminous quasars is undermassive compared to that predicted by the local mass relation. Cosmological simulations suggest that a wet compaction event is required to feed the BHs and turn their host galaxies into bulge-dominated quiescent galaxies where local massive BHs reside. We propose ALMA band 4 observations of the CO(2-1) line at a resolution of 0.4"-0.6" to constrain the central gas content and spatial distribution of 33 quasars at z~0.5, which cover a wide range of galaxy structural properties (e.g., size, Sersic index, compactness) while controlling the stellar mass to the pivot mass of 10^10.6 Msun. The proposed observations will allow us to probe the gas mass down to 10^9.3 Msun (comparable to Mbulge) in the central 2 kpc region, and study its correlation (or lack thereof) with galaxy structural and quasar properties. This will enable a direct test of the compaction-then-quenching scenario and put stringent constraints on mechanisms that drive BH-galaxy coevolution. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-11-18T23:29:03.000 |
| 4327 | 2013.1.01173.S | 1 | Intense fireworks of star formation - ALMA observations of the brightest, most massive galaxy (proto-)cluster candidates found in the Planck survey | Fossil evidence in the nearby Universe suggests that massive galaxy clusters formed most of their stellar mass in very short, vigorous bursts of star-formation resulting in very bright (L_FIR of-order 10^14 Lsun), high-z Mpc environs which are hitherto unobserved. Through a unique synergy of the Planck all-sky survey and Herschel/SPIRE photometry we have selected a sample of the 230 brightest high-z Mpc environs on the FIR/sub-mm sky. Most are overdensities of red SPIRE sources with the typical colors of bona-fide "Herschel" high-z galaxies. We request ALMA 12-m-array 0.5" resolution dust imaging in Band 6 of 4 sources to uniquely associate the dust emission with individual galaxies in the associated strong galaxy over-densities. This will also enable us to elucidate the nature of SPIRE "blobs" without obvious stellar counterpart. Are these the vestiges of extended gas and dust that contributed to fueling the extraordinary star-formation activity through which the most massive galaxy clusters where shaped? Our program illustrates the power of ALMA, combining high sensitivity and high spatial resolution, on truly outstanding objects in the early universe. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2016-07-03T16:29:07.000 |
| 4328 | 2013.1.00836.S | 11 | Gas-Mass Evolution in Milky Way Progenitors at z~1.3 | Although there is a growing number of detections of cool gas in distant galaxies, these have been limited to rarer high mass, high SFR objects. We have almost no knowledge of the cool gas in more moderate-mass, "typical" galaxies, including the progenitors of our own Milky Way. Here we propose to obtain the first measurements of cold gas in four "typical" galaxies at 1.2 < z < 1.4 using ALMA Band 4 observations of the CO(3-2) emission line. We have carefully selected the target galaxies from our deep near-IR ZFOURGE/CANDELS survey such that they have the mass (Log M*/Msol = 10.2) and SFR (=20 Msol/yr) of Milky Way-sized galaxy progenitors. The target redshift range corresponds to when Milky Way-type galaxies transition from forming stars at their near-peak rate to when their star formation quenches, and it is also when these galaxies began to form bulges. With these data we will (1) measure the gas masses and (2) measure the star-formation efficiency. We will correlate these measures against other galaxy properties (including bulge fraction) to understand what mechanisms lead to the decline of star-formation in Milky Way-sized galaxies. | Galaxy structure & evolution | Galaxy evolution | 2016-07-31T08:16:47.000 |
| 4329 | 2018.1.00271.S | 1 | Substructures in Compact Protoplanetary Disks | ALMA has shown in spectacular fashion that bright rings, gaps, and spirals are common features in protoplanetary disks. While the origin of the structures remains highly debated, the ubiquity of substructures must signify an important step in the planet formation process, either by indicating the process by which dust accumulates in disks to facilitate planet formation, or by indicating the gravitational interaction of nascent embedded planets. Since existing high resolution observations are biased toward the largest and most luminous disks, an important question is whether such substructures are prevalent in the more typical, compact systems. In this proposal, we request time with ALMA to image a carefully selected sample of disks that are smaller and less luminous than 95% of the disks in the recently completed Large Program. The goal is to empirically establish the prevalence of substructure, or lack thereof, in compact disks. Our sample consists of 9 sources that have radii between between 18 au and 46 au, and thus are more typical of disk sizes and indeed more akin in size to our Solar System. | Disks around low-mass stars | Disks and planet formation | 2021-03-17T23:25:42.000 |
| 4330 | 2022.1.01284.S | 29 | Differentiating between Grain Growth and Planet Driven Sub-structure in Protoplanetary Discs | Radial and/or azimuthal sub-structures of dust and gas in protoplanetary disks are frequently revealed by ALMA observations. Dust particles drift towards higher gas pressure and are trapped in pressure maxima, which can be created at the outer edge of the planet orbit or a dead zone. Recent re-analysis of archival VLA data has revealed radial sub-structures at long wavelengths (>7mm). By comparing these results with ALMA observations across a large span in wavelegnth (1.3 mm vs. 2.4 mm) at high resolution, we will test if dust trapping is the cause for the observed structures. Combining multi-wavelength observations is the key to disentangle between gap-forming physical mechanisms and would vastly accelerate our understanding of the theory of planet formation and disc-planet interaction. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2024-09-12T17:16:15.000 |
| 4331 | 2019.1.00171.S | 26 | First ALMA images of the water snowline on disk scales | Despite its key role in planet formation and the emergence of life, only three spatially resolved observations of water around young stars have been published, and all of them are pre-ALMA. Ultimately, astronomers want to image the water snowline, i.e., the radius at which gas-phase water freezes out onto dust grains, in protoplanetary disks, because this will allow predictions from planet formation models (e.g., about the formation of dust rings and the C/O ratio in planetary building blocks) to be tested observationally. However, water observations in mature disks are very challenging, so a first step is to image thermal water emission in more luminous protostellar sources on disk scales. We therefore proposed Cycle 5 observations of H218O toward four protostars as soon as Band 5 became operational, to directly image the water snowline. A second goal was to establish H13CO+ as an alternative tracer of the snowline. Unfortunately, only the H13CO+ observations were executed. We here propose to fulfill the key goal of the program by observing H218O toward the two best targets. | Low-mass star formation, Astrochemistry | ISM and star formation | 2021-02-21T11:57:57.000 |
| 4332 | 2023.1.01719.S | 6 | What is the Origin of the Mysterious Infrared Excess in Quiescent Black Hole Binaries? | We will observe the quiescent black hole binary, V404 Cyg, with JWST and ALMA. This is a prototype of the class of 'electromagnetic black holes' with normal stellar companions, in contrast to binary stellar mass black holes identified by LIGO. V404 Cyg exhibits an IR excess in Spitzer observations above that expected from either the secondary star or the accretion disk. Two explanations are proposed. Either it originates from synchrotron emission from a relativistic jet that persists into quiescence or from a large, cool circumbinary disk. We will discriminate between these possibilities by using the large throughput and sensitivity of JWST coupled with simultaneous ALMA observations of the radio jet to search for mid-IR variability and multiwavelength correlation and measure the mid-IR-mm spectral energy distribution. No short timescale variability is expected from a circumbinary disk so variability, especially if correlated with ALMA, would falsify the disk model and confirm mid-IR jet emission. [... See original JWST proposal for last 3 sentences in Abstract] | Black holes | Stars and stellar evolution | 2024-10-19T11:36:21.000 |
| 4333 | 2023.1.00963.S | 62 | An ALMA-MUSE survey of z~3 quasars: deciphering their multiphase gas reservoirs and small-scale environment | The study of multiphase gas reservoirs around quasars and their small-scale environment is key in understanding their fueling and feedback during galaxy evolution. At z~3, rest-frame UV surveys routinely report the detection of Lyman-alpha nebulae with diverse sizes and brightness. These nebulae represent a large supply of cool halo gas, with inferred densities as high as those in the interstellar medium. Notwithstanding these results, little is known about the molecular content of these systems. In this framework, an APEX survey targeted 9 z~3 quasars already observed with VLT/MUSE, finding large velocity shifts between the molecular and ionized phase, and that the most massive molecular gas reservoirs are associated with the dimmest and some of the smallest Lyman-alpha nebulae. To confirm these observations and better capture the link between the multiphase reservoirs around quasars, we propose to target with ALMA band 3 the CO(4-3) transition in 37 z~3 quasars already observed with MUSE. Such an unprecedented large and homogeneous sample of ALMA-MUSE observations will characterize the different gas phases around quasars, and constrain their environment in obscured tracers. | Lyman Alpha Emitters/Blobs (LAE/LAB), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2025-01-11T11:48:07.000 |
| 4334 | 2018.1.00510.S | 59 | Finding the precursor of HL Tau | The spectacular images of HL Tau and other highly resolved protoplanetary disks with sharp rings and gaps have mesmerized the astronomical community: what is the origin of these gaps? What is even more striking is that gaps are seen at every stage, from 0.5 Myr to 10 Myr old systems, suggesting that gaps are formed very early on. We propose to observe the deeply embedded NGC1333-IRAS4A Class 0 protobinary at 0.045" resolution at 1.3 mm and 2.0 mm to test if gaps already exist in an 100 kyr old system. IRAS4A consists of two very young disks at 1" separation, recently resolved at 70 mas resolution in VLA data. The 4A1 component is one of the brightest and most well studied Class 0 disks in the sky, and thus most suitable for this kind of study. The high resolution observations are expected to be exemplary for the power of ALMA and will help to determine the origin of gaps in protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2021-01-10T21:34:59.000 |
| 4335 | 2012.1.00105.S | 1 | Where the Gas Meets the Stars: The Young Super Star Cluster in NGC 5253 | We propose to observe the kinematics and distribution of CO(3-2), 13CO(3-2) and dust continuum in the giant molecular cloud associated with the young embedded super star cluster in the galaxy NGC 5253, to examine the dynamics and structure of the gas clouds surrounding this embedded young cluster on parsec scales. | Starbursts, star formation | Active galaxies | 2016-09-09T05:25:29.000 |
| 4336 | 2024.1.00722.S | 0 | Detecting gaseous water in a warm exo-asteroid belt and testing a new mechanism to deliver water to exoplanets | In our solar system, it is thought that a large quantity of water was brought to the inner planets after their formation by asteroid impacts. We want to explore a new scenario that could explain the supply of water to the inner regions of exoplanetary systems. Water ice has been detected in a warm exo-asteroid belt and should sublimate freely given the belt temperature, releasing gaseous water. We have developed a new model to track the gas sublimation and subsequent viscous evolution in the inner regions of warm belts. The gaseous water will eventually encounter planets and be accreted onto them in significant quantities. The aim of this proposal is to detect and characterise gaseous water in the warm asteroid belt around HD 69830, where water ice has already been observed by the Spitzer space telescope. Such observations of gaseous water have already been made with ALMA in a protoplanetary disc, and simulations indicate that the gas quantity anticipated in HD 69830 can be observed by ALMA with the required sensitivity. If water were to be detected, this observation would be the first in a long series, which could revolutionise models of the planetary evolution of inner systems. | Debris disks | Disks and planet formation | 3000-01-01T00:00:00.000 |
| 4337 | 2016.1.00645.S | 118 | Massive and dense clumps in early stages of evolution: mass distribution and turbulence | We have identified two massive and dense molecular clumps in early, but slightly different, stages of evolution: one in the quiescent phase and the other in the protostellar phase. Both clumps have line profiles exhibiting the blue asymmetry signature of global collapse. These are ideal objects to test current high-mass star formation models and to investigate the incidence of turbulence in clump evolution. We propose to observe four molecular lines (HCO+, H13CO+, CH3CN, N2H+) in the 3mm window, using both the 12m and 7m arrays, to measure temperatures, densities and gas dynamics of the molecular gas on both, the large (20´´) clump scale and small (2´´) core scale. These observations will allow us to determine the number and distribution of individual cores, their physical properties and dynamical state, as well as the density, temperature and velocity field of the large scale clump as a function of radius, which will give the large scale mass infall rate. The characteristics of both the global collapse and of the primordial fragmentation, together constitutes a key discriminator between the monolithic collapse and competitive accretion scenarios for high-mass star formation. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-02-10T18:34:38.000 |
| 4338 | 2018.1.00976.S | 57 | Mapping the youngest pulsar wind nebula in the Galaxy | Pulsar wind nebulae (PWNe) are Nature's best particle acceleration laboratories. Young pulsars and young PWNe are very dynamic and can show evolutionary effects on timescales of a few years. Most young PWNe have been discovered and studied in X-rays, where the fluxes and spectral parameters of distinct jet and torus structures constrain the properties of the highly-relativistic pulsar wind particles, the acceleration mechanisms, and the geometry of the pulsar. Mm observations of PWNe can provide additional constraints, e.g., on the energy spectrum of the injected pulsar wind particles. The PWN in the supernova remnant Kes 75 was recently confirmed to be the youngest PWN in the Galaxy (380-520 years, Reynolds et al 2018). This PWN provides an unique opportunity to study the early evolution of a PWN and its powering pulsar. The PWN shows distinct small-scale (<10 arcsec) features in X-rays, e.g., jets. Different PWN regions have different X-ray spectral properties. We propose ALMA observations at a similar spatial resolution as the existing X-ray data in order to study the small-scale PWN morphology in the mm, and to constrain and compare their spectral properties in X-rays and mm. | Pulsars and neutron stars | Stars and stellar evolution | 2020-08-10T16:13:54.000 |
| 4339 | 2015.1.01270.S | 20 | From Hydrocarbons to Dust in Protoplanetary Nebulae | We propose to observe two carbon-rich protoplanetary nebulae (PPNe), CRL 618 and CRL 2688, to investigate the physical and chemical conditions that lead to complex hydrocarbon chemistry in the circumstellar environment of evolved stars after the AGB phase. These two transition objects are characterized by a different temperature, hence UV field, of the central star. Polyacetylenes and cyanopolyynes have been detected in both sources but benzene, the first aromatic ring, is only seen in CRL 618. Emission from carbon dust of mixed aromatic/aliphatic composition is only seen in CRL 2688. For both molecules and grains, UV-processing was invoked as a key process in driving the chemical evolution. We aim to reconcile these observational facts and get new insights into the gas and dust chemistry.The physical and chemical conditions are retrieved from studying HCCCN, CCH, HCN, CN, and CO. For CRL 618 we also observe HCO+ and a recombination line of Hydrogen to characterise its compact photodissociation region (PDR). Only with ALMA can we accurately probe the densest, smallest regions (at scales of 0.2 to ~1") where the most active chemistry is expected. | Post-AGB stars, Evolved stars - Chemistry | Stars and stellar evolution | 2017-12-12T15:48:46.000 |
| 4340 | 2021.2.00151.S | 79 | An ACA pilot study of dust properties and SFR in QSOs at EoR | This proposal aims at obtaining a reliable estimate of the dust temperature, dust mass and FIR star-formation rate, with a typical statistical uncertainty of 20%, through band 4-8-9 photometry, in the host galaxies of a sample of 5 objects drawn from the HYPerluminous QSOs at the Epoch of ReionizatION (HYPERION) Survey. HYPERION is a 2.4 Ms XMM-Newton Multi-Year Heritage Programme targeting the titans among z >6 QSOs, that are powered by the fastest-growing and most massive Super Massive Black Holes (SMBH) at their epoch, and that probably assembled from the largest BH seeds, or experienced peculiar, possibly supercritical, mass accretion histories. The HYPERION QSOs are remarkable targets for the study of the mass assembly of their host galaxies, and this can be attained by measuring the SFRs, dust temperatures and masses. Measuring these quantities with high accuracy is the missing pillar to build a reliable overview of the host galaxy growth rate, particularly crucial in this sample whose selection is physically motivated by the fast QSO growth history. This is a pilot program that take advantage of the ACA high-frequency capabilities to study the 5 brightest QSOs in Hyperion. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-10-11T15:21:05.000 |
| 4341 | 2012.1.00707.S | 20 | Outflow structure and origin of the high-J CO excitation processes toward low-mass embedded protostars | Our recent Herschel results reveal highly rotationally excited CO emission lines toward a sample of young low-mass embedded protostars, which we can reproduce with radiative transfer models that require a combination of two thermal gas populations dominated by UV- and shock-heating processes. Spatially and spectrally resolved observations are needed to test our predictions for how the outflow structure and conditions within the outflow cavity and along the walls agree with the relative contribution predicted for each heating mechanism, as well as to explain the variation in high-J CO emission seen across the sample. In addition, new models show how a single temperature gas component may also be sufficient to describe the high-J line emission. We propose to observe the CO (2-1) and (6-5) line emission toward 7 of our Herschel embedded sources in order to examine the validity of both models and to determine the relationship between the main excitation mechanisms and the outflow structure and source evolutionary stage. Our source sample consists of 2 sources characterized by shock-heating, 2 sources dominated by UV-heating, and 3 sources by a combination of the two processes. By probing the (6-5) line in Band 9, we bridge the (rotational) energy gap between the cold gas probed by existing interferometers and the (unresolved) warm gas components revealed by Herschel, for the first time. Our goal is to verify whether the spatial distribution and the ratio of the integrated line intensities match up with the model predictions. This project will target the physical interaction region of the outflow with the envelope, providing insight into how energy is returned to the interstellar medium during star formation, and assessing how well our emerging outflow picture describes the full CO ladder and the physical origin of the excitation processes required to produce the high-J CO lines observed by Herschel. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2017-01-29T18:49:59.000 |
| 4342 | 2012.1.00683.S | 3 | Sub-millimeter excess in a low metallicity cloud in the Magellanic Bridge | The Magellanic Bridge is a filamentary structure of about 15 to 21 kpc seen in neutral hydrogen (HI) lying between the LMC and the SMC. It represent the nearest tidally interaction between these two galaxies some 200 Myr ago. It has a lower metallicity than the SMC and therefore allow to study the ISM in extreme conditions. Recent studies have revealed the presence of young (< 200Myr) massive stars and CO molecular clouds. The latter are barely resolved in single-dish observations and are spatially related to warm dust emission sources, as recently established by the Spitzer SMC-SAGE and Herschel HERITAGE studies. We have obtained 870 micron images of one of these sources, Magellanic Bridge Source A. Surprisingly, its dust emission shows a large submillimeter excess, indicative of either very cold dust or a dramatically different submillimeter emissivity. We propose to study this source in CO(1-0) and (2-1) and the associated continuum at arcsecond resolution to determine the physical properties of the molecular cloud. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2016-03-30T13:06:45.000 |
| 4343 | 2019.1.01197.S | 67 | Probing Gas, Dust, Stars, and Star Formation Activity down to 100-pc Scales using Strong Gravitational Lensing | Herschel and other submm/FIR surveys have shown that dusty star forming galaxies (DSFGs) with SFR 100-1000 M_sun per year are ubiquitous in the early Universe. Yet, they remain a challenge for theoretical modeling because of complex interplay among gas accretion, star formation, and feedback processes occurring on 10-100 parsec scales that are beyond observational or numerical resolution today. We are addressing this challenge on the observational front by utilizing the magnifying properties of strong gravitational lensing. Our Cycle 5 shallow low-resolution imaging survey of 15 Planck-selected SMGs, with apparent luminosity exceeding 10^14 L_sun, have successfully shown that all of our targets are indeed strongly-magnified sources at z>1. To provide a direct view of the most luminous DSFGs known at spatial scales where the star formation process usually takes place, we propose deeper, higher resolution CO(3-2) and 1mm continuum observations of the 2 best-suited Planck SMGs with bright CO lines and a clean lensing geometry, both of which are situated at the peak of Cosmic SF evolution (z=2-3). | Sub-mm Galaxies (SMG) | Galaxy evolution | 2022-09-01T19:40:13.000 |
| 4344 | 2021.1.01406.S | 20 | Resolving kinematics of a giant gas disk at a z=3 protocluster core using [CII] | Submillimeter-bright galaxies (SMGs) are dusty, gas-rich, high-z galaxies that show intense starburst activity. SMGs are possible progenitor of early type galaxies in the center of the cluster in the local Universe, and thus SMGs in a proto-cluster in the early Universe can play a key role in understanding the formation and evolution of the most massive galaxies across cosmic time. Here we propose a deep [CII] imaging of a bright SMG located at the z=3.1 SSA22 proto-cluster core. The CO(3-2) emission reveals a giant gas disk on more than 30 kpc scale, and the suggested rotation velocity is about 600 km/s. These characteristics, together with the proto-cluster environment, make the SMG an important target. Using the bright [CII] line as a reliable tracer, we will uncover gas kinematics of the gigantic gas disk at z=3, and how the proto-cluster environment influences the growth of galaxies and SMBHs in the early epoch. | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-06-28T08:39:47.000 |
| 4345 | 2016.1.00314.S | 118 | Dissecting to decipher: an ALMA study of the high-mass star formation processes in RCW 120 | Two scenarii are proposed for the formation of massive stars: strong accretion fueled by a high degree of turbulence or competitive accretion. Each scenario can be uniquely identified during the early phases of high mass star formation by looking at the fragmentation and dynamical processes at high resolution in the millimeter wave range. Recent ALMA and PdBI results in high mass star forming regions show either a high degree of fragmentation (Rathborne et al. 2015, Beuther et al. 2013) or filaments' collision converging on a high mass core (Fukui et al. 2015). We suggest that the mechanism controlling the high mass star formation might depend on the immediate environment of the high mass core. We propose to test this hypothesis by observing with ALMA Band~3, 6, and 7 the continuum and line emissions towards two massive young sources located at the edges of RCW 120, in the highest column density part of its photodissociation region. The sources are in different evolutionary stages and lie in different environments. With ALMA data we will characterize their true spatial structure and derive their velocity structure to identify the mechanisms that drive their formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-06-18T19:25:03.000 |
| 4346 | 2019.1.00463.S | 52 | Building Bridges: Large to Small Scale Envelope Structure around BHR7 | In order to understand the formation of disks around protostars, it is crucial to trace the kinematics of the rotating and infalling gas from the core and envelope (scales ~ 0.1 pc) down to the disk (scales ~ 10s AU). To date there are no complete studies linking the dynamics from scales (~0.1 pc down to 10 AU) for a single system. SMA and IR studies have uncovered a nearby (~400 pc), protostellar source forming within an isolated core, BHR7. It has a marginally resolved disk in dust continuum with possible Keplerian rotation and bipolar outflows, indicative of active protostellar mass assembly. This is an ideal ``archetypal'' source that is isolated, near edge-on, enabling a unique opportunity to disentangle the kinematics of envelope infall, disk rotation, and outflows, unlike many other sources. We propose ALMA observations using the inner envelope and disk tracer, C18O, and outer envelope tracer, N2H+, to map the inflow and angular momentum from the outer envelope down to the disk. ALMA is the ideal facility able to image this ``archetypal'' system with simultanous high spatial/spectral resolutions and high sensitivities to large angular scales. | Intermediate-mass star formation, Astrochemistry | ISM and star formation | 2021-04-02T21:17:04.000 |
| 4347 | 2012.1.00952.S | 0 | Molecular gas content of EXTREME outliers from the star-forming main sequence at z~1.5 | It is currently unclear as to whether the most rapidly star-forming galaxies operate in a mode of star formation dissimilar from that of the majority that populate the so-called Main Sequence (MS) of star-forming galaxies. Two scenarios are commonly considered. In one of them, the sudden accumulation at the bottom of the potential well of a large amount of gas triggered by a major merger (or by a disk instability) is boosting a highly efficient conversion of gas into stars. Alternatively, MS outliers may form stars in the same mode (i.e. efficiency) as MS galaxies, but just happen to be exceptionally gas rich. With the remarkable sensitivity of ALMA, we can now directly test this by determining whether the star formation efficiency (=LIR/LCO) is statistically different from that of MS galaxies. A new ‘intensive’ near-infrared spectroscopic survey of over 2000 star-forming galaxies in COSMOS with 1.2 < z < 1.7 using Subaru/FMOS is enabling us to identify a robust sample of galaxies detected by Hershel/PACS and having extreme offsets from the MS. We propose to use ALMA to obtain CO measurements for such galaxies with accurate spectroscopic redshifts and SFRs based on Hα and FIR luminosity. These ALMA observations will nicely complement published CO studies of main-sequence galaxies and lay the groundwork for future (sub)mm studies of such extreme events including those at higher spatial resolution. | Starbursts, star formation | Active galaxies | 2015-06-03T12:59:10.000 |
| 4348 | 2019.1.00799.S | 26 | Formaldehyde deuteration in the protoplanetary disk of DG Tau: the organics trail from protostars to the solar system | The origin of organics in the solar system (SS) is a key unanswered issue. Is the composition of the SS inherited from the prestellar phase? Or does it reflect chemical processing in the protosolar nebula? Deuteration is a powerful tool to answer these questions as it strongly depends on the molecules formation environment. High deuteration of organics (e.g. formaldehyde H2CO) in protostars (~0.04-1) is thought to be the signature of cold ice chemistry in the pre-collapse phase, whereas deuteration in the SS is lower (<0.01). There is a missing piece of information: what is the organics deuteration in protoplanetary disks (PPDs), where planets, comets, and meteorites form? Organics are mostly frozen on ices in PPDs, therefore their gas-phase abundance is low, making the detection of their less abundant deuterated forms a real challenge. To fill in the gap we propose ALMA-Band 5 deep observations of HDCO towards the nearby DG Tau disk to complement H2CO observations probing the outer disk ices. This will allow us to obtain the FIRST estimate of H2CO deuteration in a PPD and to compare it with that in protostars and in SS, thus testing the inheritance versus disk reset scenarios. | Astrochemistry | ISM and star formation | 2022-10-20T18:11:36.000 |
| 4349 | 2019.1.01587.S | 35 | The TRICEPS survey: Tracing Rotation with Ionized Carbon in Early Primeval Systems | Rotation curves (RCs) are a prime tool to study baryons and dark matter (DM) in galaxies, providing strong constraints to galaxy formation models. RCs have been derived for hundreds of galaxies at z=0 and for some objects at z=1-2, but no systematic study exists at higher z. In Cycle 6 we obtained [CII] data at 0.1" resolution for one galaxy at z=4.8: our pilot study demonstrates that ALMA can be used to trace RCs and DM at this z. We propose the TRICEPS survey: the first systematic study of RCs at z=4-5. We request [CII] data at 0.05"-0.1" resolution for 10 objects that were previously observed at lower resolutions. The archival data shows rotation signatures but do not allow a detailed study. Six of our galaxies are in pairs giving us 10 objects at the cost of 7. We will (1) map the [CII] distribution and kinematics at sub-kpc scales, (2) distinguish between regular rotation and non-circular motions (inflows, outflows, tidal disturbances), (3) derive RCs and decompose them into baryons and DM, (4) study gas turbulence. The [CII] line is one of ALMA flagships: after several low-resolution [CII] surveys, our program is timely to exploit the full resolving power of ALMA at high z. | Galaxy structure & evolution | Galaxy evolution | 2022-09-13T00:00:00.000 |
| 4350 | 2012.1.00973.S | 53 | Using ALMA and Herschel-ATLAS to probe the evolution of gas in galaxies over the past 5 Gyr | The recent result from Herschel-ATLAS that the dust masses of galaxies are evolving strongly over the past 5 Gyr (Dunne et al. 2011) suggests that the gas content of galaxies may also have been much higher in the relatively recent past. Measuring the evolution of galaxy gas masses and gas fractions is an important step towards a full understanding of galaxy evolution but has not been practically possible in the past. New, large sub-mm samples from Herschel now offer a way to trace the evolution of gas mass and gas fraction in galaxies over large swathes of cosmic history due to the unparalleled sensitivity and scanning speed of Herschel. To do this, it is first necessary to calibrate the dust emission at the redshifts of interest against known and quanitified tracers of molecular gas content. This proposal aims to do just that for a reprensentative sample of 12 sources at z=0.35 from the Herschel-ATLAS, measuring their CO(1-0) and CI(1-0) lines in order to calibrate dust as a tracer of gas. This calibration can then be applied to samples of several tens of thousands of sources out to z=1 where the strongest changes in gas content and star formation rate are expected. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2015-04-29T20:21:08.000 |
| 4351 | 2022.1.01778.S | 2509 | Constraining the Accretion Properties of Nearby High-mass AGNs | The horizon-scale observations of M87 are well modelled by synchrotron emission from a thermal particle distribution function [eDF]. However on larger scale the observed spectra is in good agreement with a non-thermal eDF. Thus the question arises where and how the thermal particles are accelerated into the non-thermal distribution. For studying and addressing these questions simultaneous multi-frequency observations are crucial. We thus request Bands 3, 6 and 9 ACA observations of 73 nearby AGNs. The millimetre spectra will allow us to test different accretion models and thus test the opacity of the flows. The high-frequency capabilities of the ACA will allow us to study the turnover-regime of the spectrum (transition between optically thick and thin emission). Thus capturing the spectral turnover position will not only provide a tight constraint on the particle distribution function (and possible acceleration mechanism) but will also allow us to estimate the contribution to the high-energy emission via the synchrotron self-Compton process. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2023-10-24T22:56:23.000 |
| 4352 | 2012.1.00332.S | 1 | Fueling the AGN in the Seyfert 2 Galaxy NGC 4945 | One of the enduring mysteries in extragalactic astronomy is how gas is transported into the centers of spiral galaxies to fuel their active supermassive black holes. Here, we propose to map at a spatial resolution of just 3 pc the molecular gas in the Seyfert 2 galaxy NGC 4945. At a distance of ~3.8 Mpc, NGC 4945 is, by far, the nearest Seyfert galaxy so far mapped in molecular gas. Our CO(2-1) observations with the SMA show that NGC 4945 exhibits molecular gas corresponding to the inner region of the large-scale galactic disk that can be traced out to several hundred parsecs, a concentration in molecular gas at a radius of ~80 pc coincident with a starburst "ring," and a nuclear disk with a radius of just ~20 pc. Rather than comprising separate features, our hydrodynamical simulation suggests instead that what appears as a distinct nuclear disk and molecular (starburst) ring arise from a tightly wound two-arm spiral. Such a nuclear spiral enables gas to be transported from scales of > 100 pc down to the angular resolution limits of our observations through shocks in the spiral arms that dissipate angular momentum. Our goal is to find out whether the molecular gas is truly infalling toward the AGN to fuel its activity. To do this, we first need to determine whether the previously observed rapidly-rotating disk and the molecular (starburst) "ring" in NGC 4945 are truly distinct structures, or they conform to a two-arm spiral as suggested by the simulation. In case of a two-arm spiral, we calculate the gas inflow rate based on the 3 pc scale molecular gas kinematics. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-03-03T03:54:15.000 |
| 4353 | 2017.1.00907.S | 18 | WISDOM: From Small-Scale Strucutre to Galaxy-Scale Processes | Observations of molecular gas at both GMC and galactic scales in external galaxies are key to understanding the molecular cloud (MC) formation and the relation of small-scale structures to galaxy-scale processes. Although the exquisite resolution of ALMA allows us to effortlessly resolve individual GMCs in nearby galaxies, we have demonstrated a need for low-resolution ALMA maps in GMC studies to allow complete flux recovery and total mass measurement of cold gas. We aim to 1) accurately measure MC (including low-mass MCs) properties and study their relations to galactic environment, using a high-sensitivity map combining high- and low-resolution observations; 2) investigate Larson's relations in external galaxies; 3) study star formation relations from large galactic-scales and small GMC-scales; and 4) determine the conversion factor between CO flux and H2 mass using the virial mass method. Our work will use a uniform methodology to perform a comprehensive analysis of MCs properties across different galaxy environments. Our aim is to address multiple key open issues regarding MC formation/evolution and their relationship to the wider galactic environments. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2019-05-14T08:42:45.000 |
| 4354 | 2018.1.00192.S | 66 | A survey of prestellar, high-mass clump candidates: constraining models of high-mass star formation | [This is a re-submission of a previously approved B-rank proposal (2017.1.00716.S) from Cycle 5. At the moment, 10% of the project has been observed (only 7m and TP). We will withdraw the observations from this Cycle 6 for targets that are observed in Cycle 5]. The lack of a significant amount of prestellar, high-mass cluster-forming clumps has made hard to conclusively refute or support models of high-mass star formation. In addition, the insufficient sensitivity and angular resolution have done challenging to unambiguously test observational predictions. In our pilot survey, we dectect no high-mass prestellar cores, the more massive cores (<18 Msun) are subvirialized, and surveys that only make single-pointing observations are highly imcomplete. Expanding on our pilot survey, we aim to observe a complete sample of prestellar high-mass clump candidates with masses >500 Msun, temperatures <16 K, distances <5 kpc. All our targets are IR-dark up to 70 um. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-02-04T15:53:55.000 |
| 4355 | 2018.1.01008.S | 77 | Gravitational lenses as cosmic telescopes: Resolving AGN feedback on 100-pc scales at z~3 | While there have been detailed studies of AGN feedback in the local Universe, at high redshift these processes are difficult to study due to the small scales involved. We propose gathering CO line data on a sample of 10 gravitationally-lensed quasars at z=2-4. Using a pixelated source reconstruction method, the lensed sources will be spatially resolved on 50-150 parsec scales as studied at redshifts <1. Using sophisticated radiative transfer modelling techniques, we will perform a comprehensive study of the ISM properties of the sources to derive gas dynamics, densities, extents and excitation temperatures for these systems. By resolving the structure and dynamics of molecular gas on physically-important scales where AGN- and SF-heating dominate, we can construct a comprehensive picture of the radiative and mechanical energy injection into the host galaxy and test models of AGN feedback at cosmologically interesting epochs. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2020-12-15T17:11:27.000 |
| 4356 | 2016.2.00098.S | 25 | Extended Molecular Outflow in a Nearby Active Galaxy | Outflows driven by AGN are believed to be signatures of feedback in action in the host galaxies of accreting black holes. Outflows are observed both in molecular and ionised gas, but their acceleration mechanisms are still debated. In Cycle 4 we were awarded 12m ALMA time to obtain CO(2-1) observations of a local active galaxy showing extended ionised outflowing gas via optical nebular line. In the inner regions the CO(2-1) emission reveals high velocity wings, which are cospatial to the emission of the ionised outflow. At large radii, however, our observations do not reveal the presence of extended diffuse fast gas. Since we cannot exclude that the current 12m ALMA observations resolve out completely extended molecular outflow emission, we propose observations of CO(2-1) with ACA to assess the morphology and the size of the molecular outflows up to large scale. By combining 12m ALMA observations with the ACA images we will compare the properties of the molecular and ionised fast gas in compact and extended regions unveiling the nature of multi-phase AGN-driven outflows. This observation will be crucial to asses the impact that such outflows may have on the host galaxy. | Outflows, jets, feedback | Active galaxies | 2019-01-16T12:29:23.000 |
| 4357 | 2017.1.01376.S | 158 | Highly deuterated starless cores with low CO freeze out: a chemical puzzle | Deuterated molecules, in particular N2D+, are excellent tracers of cold, dense gas, and thus they are ideal tools to study the initial conditions in the process of star formation. The deuterium fraction is known to decrease outside of the CO depletion zone in dense cores. Recent observations have revealed the presence of dense cores with high deuterium fractions and low CO-depletion factors which contradicts chemical models of dense cores. One way to reconcile theory with observations is to have small or clumpy cores. We propose to observe the N2D+(3-2), N2H+(3-2) and C18O(2-1) transitions and dust continuum emission towards eight highly deuterated starless cores which show low CO freeze out, in L1688, in Ophiuchus. We will measure the deuterium fraction, the CO depletion factor and dense gas distribution, traced by the N2D+ and N2H+ (3-2) transitions, on 5" scales. We expect the dense gas to be concentrated in small (~5-10") CO depletion zones not detected with prior single dish measurements. Alternatively, extended N2D+ emission in CO rich gas would testify to peculiar environmental conditions in these cores, such as low cosmic ray ionization rates or atypical dust grain sizes. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-10-15T12:13:09.000 |
| 4358 | 2011.0.00268.S | 0 | Metallicity of a Submillimeter Galaxy at z=5 | Metallicity of galaxies and its redshift evolution are crucially important to give constraints on galaxy evolutionary models. Although such studies at z>4 is extremely interesting to understand the early evolutionary stage of massive galaxies, optical or near-infrared observations cannot assess the metallicity of star-forming galaxies at z>4. Here we propose a brand-new method to infer the metallicity of galaxies using a flux ratio of fine-structure lines, [NII]205/[CII]158, whose robustness is fully examined by our photoionization model calculations (taking both HII regions and PDRs into account). This new metallicity diagnostic is applicable for galaxies at z>4, where the [CII] and [NII] lines shift into the submillimeter atmospheric windows. Note that the [NII]205/[CII]158 flux ratio is insensitive to the dust reddening (unlike optical diagnostics), and thus it is applicable for dusty galaxies that are in the actively evolving phase of the galaxy evolution. In the ALMA cycle 0, we propose to apply our new metallicity measurement method to a submillimeter galaxy at z=4.75. Our previous identification of strong [CII] emission in this object makes feasible to detect the [NII]205 emission in this galaxy using ALMA, even in the cycle 0. Based on the inferred metallicity, we examine the timescale of the early chemical enrichment in massive galaxies and the origin of the “[CII] excess” in high-redshift [CII] emitters. | Galaxy structure & evolution, Galaxy chemistry | Galaxy evolution | 2013-02-09T01:45:00.000 |
| 4359 | 2015.1.00384.S | 7 | Detailed molecular gas distribution of an active star forming region within a low-metallicity environment: CI observations of N83 in the Small Magellanic Cloud(SMC) | The aim of this observation is to reveal for the first time the detailed molecular gas distribution of an active star-forming region within a low-metallicity environment to understand the formation and structure of GMCs as well as the star-formation process at low metalicity. We propose mosaic observations toward a molecular clump associated with the active star-forming region N83 in the SMC in [CI] with a final angular resolution of 1.5 arcsec, corresponding to a spatial resolution of 0.44 pc. CO observations in Cycle 2 will be used to precisely determine the density and temperature of the CO gas, and in combination with the velocity information, we can investigate the dynamics of hot-dense molecular clumps associated with HII regions and cold-dense molecular clumps prior to massive star formation. [CI] line is an important probe to reveal the distribution of molecular gas without CO emission, being a significant mass component of the cloud in low metalicity environment, affecting the system's self-gravity and providing an additional supply of gas to fuel star formation, and also a key to understand the variations of the CO-to-H2 conversion factor. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2020-10-07T00:00:00.000 |
| 4360 | 2013.1.00569.S | 2 | The origin of H2O emission and molecular outflows in IR-luminous galaxies | Water lines provide a unique probe of luminous IR galaxies, since (unlike e.g. CO) they measure the local IR radiation field. Herschel has shown that all local ULIRGs emit strong H2O lines, from highly obscured (opaque at 100 micron), IR-luminous regions with high local IR radiation pressures, which may play a role in driving the molecular outflows. However, progress is hampered by the lack of spatial information. We will take a major step forward by using ALMA for the first spatially resolved study of H2O emission (3 lines, providing the full diagnostic power), FIR continuum, OH+ emission/absorption (tracing the molecular outflow) and CO(7-6) and [CI] (tracing the high and low excitation molecular gas). We will observe (6 lines in 3 tunings) the gravitationally lensed galaxy SDP17b (z=2.3), at 0.25" resolution (850 pc in the source plane), obtaining the full position dependence of excitation conditions, importance of radiation pressure, occurence and velocity of outflow, and relation to the underlying gas disk. Observations of this type are the only way to probe directly the relation between IR radiation pressure and outflows, and the relation of the H2O emission to other tracers. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2016-11-15T08:11:26.000 |
| 4361 | 2018.1.00359.S | 52 | A Possible Source of 15N: Observations of Planetary Nebulae with Potential J-Type Progenitors | Isotopic ratios provide a window into the nucleosynthetic processes which have molded the chemical composition of evolved stars. Recent measurements of 12C/13C ratios in several planetary nebulae (PNe) are indicative of J-type stars, whose low 12C/13C ratios are difficult to reconcile with existing nucleosynthetic models. One suggested alternative is a helium flash which results in a flash production and ejection of 13C and 15N. The recent discovery of an extremely 15N-enriched PN showing signatures of a J-type progenitor by Schmidt et al. lends credence to this idea, and suggests that these objects could be important sources of 15N in the Galaxy. In order to explore this idea, we propose to image several PNe with potential J-type progenitors in transitions of HCN, H13CN, and HC15N at Band 6. By comparing the distributions of 12C and 13C across the nebulae and exploring the kinematic structure of the outflows, we may elucidate the nucleosynthetic processes resulting in such ratios. Further, the detection or non-detection of HC15N may allow us to analyze the viability of the helium flash as a model which explains the observed properties of J-type stars. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-07-29T23:34:53.000 |
| 4362 | 2016.1.00862.T | 13 | A Precision Test of Gamma-ray Burst Afterglow Models | GRBs are powered by extreme compact objects, e.g. black holes, magnetars, that eject matter at ultra-relativistic velocities (Lorentz factor >>100). This makes them ideal laboratories to study radiation processes in extreme conditions. Up to now the Swift satellite has detected >1000 GRB afterglows but only 20-30 were bright enough for extensive follow-up from radio to X-ray wavelengths to provide crucial constraints on the radiation processes. Swift has been in orbit for more than 11 years. Although all systems are still fully operational, the window to test the afterglow models gradually gets smaller. Those tests are fundamental and address key difficulties in understanding physics of cosmic particle-accelerators. Because of this, we propose a joint ALMA+APEX+JCMT+NOEMA proposal to study one GRB afterglow with a peak flux of >1 mJy from early (hours) to late times (months) for the first time. We propose to secure 5 epochs at 92 and 332 GHz separated by 7-14 days in each band. We will complement these observations with X-ray to radio data to model the broadband afterglow. This allows us to precisely test models and characterise non-standard radiation components. | Gamma Ray Bursts (GRB) | Cosmology | 2018-09-05T16:07:12.000 |
| 4363 | 2017.1.00486.S | 117 | Dust in the Reionisation Era: A New Probe of the Birth of Galaxies | Determining when the first galaxies emerged represents an exciting and fundamental observational quest. Assuming they initiated cosmic reionization, Planck measurements suggest this cosmic dawn occurred at redshifts z~10-12. In a pilot programme targeting a galaxy with deep HST and Spitzer imaging at a photometric redshift z=8.4±0.2, we demonstrated ALMAs unique ability to detect dust emission while simultaneously securing a spectroscopic redshift via [OIII] emission at z=8.38. The dust mass provides valuable insight into the earlier chemical enrichment history and when stellar nucleosynthesis began. We propose to target three further carefully-selected redshift z>8.5 galaxies with good HST and Spitzer photometry to produce the first meaningful census of the dust masses in very early galaxies with well-characterised stellar masses and star formation rates. This will provide the first estimate of when cosmic dawn occurred and form a natural springboard for complementary studies of early chemical evolution using JWST. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2019-08-31T11:32:58.000 |
| 4364 | 2021.1.00850.S | 6 | Determining the Thickness of a z~6 Disk Galaxy: Are Current Dynamical Mass Estimates Reliable? | The interstellar medium of z~6 quasar host galaxies is now routinely mapped with ALMA using [CII] and dust-continuum emission. About 1/3 of these galaxies exhibit signs of rotation, and kinematic modeling shows that they are consistent with a thin rotating disk. However the implied velocity dispersion from the available low-resolution observations is much higher than predicted by simulations; indicating that the disk might not be as thin as the standard picture predicts. A thicker disk would imply that the dynamical mass estimate for the quasar host galaxy could be significantly underestimated (by a factor of ~4), which would alleviate tension with respect to the central black hole masses. To address this, we here request 0.08"(350pc) observations of the [CII] line to accurately measure the velocity dispersion profile of the z=6.3 quasar host galaxy, J025-33 out to 1.5kpc. J025-33 is one the few known z~6 quasar hosts where this measurement can be performed. These observations will yield the first accurate measurement of the thickness of a z~6 quasar host galaxy; allowing us to constrain the 3D gas distribution, and determine if current dynamical mass estimates are accurate. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2022-11-25T23:36:38.000 |
| 4365 | 2018.1.01485.S | 0 | The physical conditions and spatial structure of the dust formation zone of IRC+10216 | We propose to study the innermost zone (1-20 R*) of IRC+10216 through the systematic observation of a significant number of vibrationally excited lines of abundant species such as HCN, HNC, SiO, SiS, SiC2 and CS. The highest angular resolution of ALMA band 6 (0.02") is requested to resolve the stellar photosphere and the region of a few stellar radii where dust molecular seeds are formed, and where shocks could be controlling the chemistry and the dynamics of the envelope. The physical conditions across the dust formation and growth zone (1-20 R*) will be fully characterized using lines from vibrationally excited states up to 15000 K in energy. We expect to obtain a unique data set from which the physical conditions and spatial structure of the gas across these inner regions will be derived. In addition, we will trace the presence of shocks, and unveil the recent mass loss history of this prototypical C-rich AGB star. These observations will also provide strong guidelines for astrochemical models, and laboratory experiments on the properties of stardust analogues. | Evolved stars - Chemistry | Stars and stellar evolution | 2021-01-03T22:32:47.000 |
| 4366 | 2018.1.00562.S | 120 | Gas and dust properties in an actively star-forming proto-cluster | Through a combination of Planck and Herschel observations, we have discovered a number of high redshift large-scale structure candidates that contain overdensities of star-forming galaxies, ideal laboratories for studying galaxy cluster formation. We have already obtained exploratory ALMA data for one of these objects, G073.4-57.5, and we detected 18 star-forming galaxies consistent with z=1-2. In two of the galaxies we detected lines, confirmed through subsequent follow-up to be CO(5-4) at z=1.54. We have also found four submillimetre galaxies in the vicinity of G073.4 with SCUBA-2 at 850 um, showing that this structure is rich with activity. We now need to confirm the remaining members of G073.4 in order to locate the most active star-forming sites and determine how they are fuelled. We propose to accomplish this by measuring redshifts via the CO(3-2) line in Band 4. In only 12 pointings and 14.9 hours of integration time we will detect over 20 submillimetre galaxies and reliably distinguish them as a cluster members or an interlopers, measure their relative velocities and calculate line diagnostics, thereby exploring the dust and gas dynamics within a high-redshift cluster. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-02-18T20:44:07.000 |
| 4367 | 2021.1.01310.S | 7 | Physical Conditions of the Young HL Tau disk | Growing numbers of observations suggest that the first steps of planet formation may be well underway when the disk is still surrounded by an infalling envelope. The fundamental physical conditions inside young embedded disks are still highly uncertain, especially on the gas mass distribution and thermal structure. The HL Tau disk is one of the youngest disk candidates for planet formation. Low resolution observations of C18O/C17O/13C18O (2-1) lines (2" resolution) towards the HL Tau disk showed that 13C18O is the only optically thin tracer of the disk. Here we propose ALMA to spatially resolve the 13C18O/C17O (3-2) lines of the HL Tau disk at 0.3" resolution to trace its gas mass distribution and the radial temperature structure. These observations will provide crucial data that can constrain physical conditions inside the best-studied early disk and demonstrate whether physical conditions in early disks are significantly different from those in Class II systems. This is a resubmission of cycle 7 grade B proposal. | Disks around low-mass stars | Disks and planet formation | 2023-08-17T21:57:21.000 |
| 4368 | 2018.1.00318.S | 9 | Revealing the overall picture of carbon atoms in the ideal plane-parallel PDR Oph-A | Revealing the picture of C+, C^0, and CO is important to investigate the fundamental carbon chemistry in PDRs. The actual situation is, however, rather complicated, and inconsistencies between the plane-parallel model and observations have been reported in past C^0 and CO studies. In ALMA Cycle 2, we investigated the picture of CO in detail as a first step, focusing on the Oph-A region. PDR models predict the presence of the CO layered structures due to the selective dissociation. However, such structures have not been detected yet. As a result of the observations of 12CO(2-1), 13CO(2-1), and C18O(2-1) with resolution of 1.4" = 0.001 pc = 180 AU, we for the first time clearly revealed that 12CO/13CO/C18O have clear layered structures with a separation of 10" = 0.006 pc, and that the 13CO/C18O abundance ratio reaches up to 30 near the PDR interface. These results indicate that CO isotopologues are indeed affected by the selective dissociation, and that Oph-A is the ideal plane-parallel PDR. As a next step, we investigate the picture of C^0 in Oph-A. Based on the [CI] map, we aim to address one of the outstanding issues in the PDR study: What does the [CI] emission reflect in a PDR? | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2021-11-11T00:00:00.000 |
| 4369 | 2021.1.00357.S | 130 | Observations of CO2 snowline tracer HCO2+ towards young bursting stars | Observationally locating the position of the CO2 snowline is crucial because it will constrain the physical and chemical conditions of disks and give information on modern theories of dust-grain growth and planet formation. However, because of the lack of a permanent dipole moment, CO2 itself cannot be observed with ALMA. Protonated carbon dioxide, HCO2+, could instead be a good tracer of the CO2 snowline position. The spatial distribution of HCO2+ is expected to be ring-shaped; the outer and inner edges of the ring corresponds to the positions of the CO2 and H2O snowlines. We here propose to confirm the effectiveness of this method and to investigate gas-phase CO2 abundance distributions by observing rotational transition lines of HCO2+ at Bands 3 and 6. Target sources are selected from young bursting stars, IRAS 15398-3359 and V883 Ori. The accretion burst is thought to be important in terms of thermal history of materials in planetary systems. One of our target HCO2+ lines has been detected towards the former object by previous single-dish survey observations, suggesting large line intensities enough for detection. | Low-mass star formation, Astrochemistry | ISM and star formation | 2022-12-01T12:48:52.000 |
| 4370 | 2021.1.00906.V | 0 | Capturing Real-Time Black Hole Dynamics in Sgr A* | Black holes are the only objects in the Universe that allow us to probe fundamental physics from stellar to supermassive scales. They host extreme astrophysical environments near their event horizons with relativistic motion, high temperature plasmas, and powerful magnetic fields. The Galactic Center supermassive black hole, Sgr A*, is the only black hole we can observe in detail from the feeding source down to the event horizon. Here, we propose to use ALMA in a global VLBI array to capture and trace the plasma activities in the immediate vicinity of the event horizon of Sgr A*. The short dynamical time scale and daily broadband flares offer unique opportunities to study dynamics near the event horizon resolved in both time and space. The proposed observation will enable us to: 1) significantly improve the fidelity of horizon-scale Sgr A* images and enable movie reconstruction with better interferometric coverage; 2) understand the origins of near-horizon plasma variability; 3) resolve the base of a jet, if it exists; and 4) provide an independent test of the scale-invariance of the black hole spacetime. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-04-24T15:53:04.000 |
| 4371 | 2013.1.01369.S | 0 | The Jets of the archetypal Galactic Microquasar SS433 | We propose to make an exquisitely detailed investigation at cm and mm wavelengths in order to understand the energetics of jet launch and propagation in the archetypal Galactic Microquasar SS433. | Black holes | Stars and stellar evolution | 2017-11-14T00:00:00.000 |
| 4372 | 2012.1.00293.S | 0 | The molecular gas in post-starburst galaxies | We propose to make the first spatially resolved CO imaging observations of two post-starburst E+A galaxies. These galaxies are unique because they show no signs of active star formation, but still contain large reservoirs of neutral hydrogen gas as evidenced by our own GBT and JVLA observations. Observational evidence indicates that the E+A phenomenon may, in part, mark the transitional phase between star-forming disk galaxies and quiescent spheroidal systems, and there is growing consensus that these galaxies are the result of galaxy mergers. Mapping the molecular gas in these galaxies will resolve the puzzle of why these galaxies have truncated their star formation - the molecular phase is most directly related to star formation activity. By studying the distribution and dispersion of the CO gas we can learn whether the gas is stable against the formation of dense molecular clouds. Also, the distribution and kinematics of molecular gas in E+A galaxies can reveal recent gravitational interactions. Counterrotating gas, which is sometimes seen in elliptical galaxies, is a clear indication that the gas has an external origin. | Starbursts, star formation | Active galaxies | 2015-01-24T00:00:00.000 |
| 4373 | 2019.1.01286.S | 55 | Measuring molecular gas reservoirs in post-starburst galaxies during the peak quenching era | We propose to quantify the molecular gas reservoirs in five post-starburst galaxies at z~1.4, during the peak era of galaxy quenching. We previously detected large molecular gas reservoirs, with masses ranging from 7x10^9-5x10^10 Msun, in six massive post-starburst galaxies at z~0.65. These intermediate-redshift galaxies probed the tail of this cosmic shut-down. Here, we propose to push this work to z~1.4 and assess whether post-starburst galaxies at the peak era of quenching also retain large molecular gas reservoirs. These observations will place direct constraints on the mechanism responsible for the truncation of star formation in typical massive galaxies. We propose to observe CO(2-1) in five post-starburst galaxies at z~1.4 with ALMA band 3. All galaxies have accurate redshifts and star formation rates from deep continuum spectroscopy, as well as sizes from HST. Using these datasets, we will place the galaxies on the Kennicutt-Schmidt relation and study how molecular gas fractions correlate with time since the burst. Furthermore, we will compare our observations with cosmological simulations to assess the different proposed mechanisms to suppress star formation in galaxies. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2021-02-21T19:15:28.000 |
| 4374 | 2012.1.00857.S | 0 | Disk rotation in Th 28: key testing of the jet impact on protoplanetary disks | Recent HST/STIS observations have shown tentative indications of jet rotation in a survey of four T Tauri systems. The rotation results suggest that jets may be the dominant agent responsible for angular momentum extraction from their inner disk. Importantly, these observations were obtained close to the base of the jet, less than 100 AU from the launch point, where external factors are less likely to confuse the intrinsic jet kinematics. Nevertheless, the jet rotation interpretation is still heavily debated. A necessary condition of the interpretation is that the sense of jet and disk rotation must agree. Of the four cases, there is agreement in two cases, but conflict in the third. Access to the disk of the fourth system has so far been denied, due to its southern declination. However, with ALMA, this access finally becomes possible. Therefore, we propose the first observations of the disk around the southern active T Tauri star Th 28 (aka Sz 102) to determine the sense of its disk rotation. We will achieve this via mapping of the disk at 0.45" angular resolution in the dense gaz tracer 13CO(3-2). If the sense of disk and jet rotation disagree in this system, it would considerably weaken the rotation interpretation and instead favor outflow ejection from a more compact region (inner disk edge or stellar magnetosphere). Conversely, if agreement is found, we have increased support for powerful magneto-centrifugal ejection originating from radii of a few 0.1 AUs to a few AUs in the disk. Such efficient angular momentum extraction by the jet would severely impact on conditions in the terrestrial planet formation zone affecting both UV driven disk chemistry and current models of planet formaton and migration, | Disks around low-mass stars | Disks and planet formation | 2015-11-10T20:31:30.000 |
| 4375 | 2017.1.01247.S | 16 | Resolving gravitationally-induced spirals in IRAS 16293 - 2422B Class 0 YSO | The development of gravitational instabilities can be a very important source of angular momentum transport in protostellar discs and is expected to cover a crucial role in the planet formation process during the early stage of the disc evolution. A complete understanding of the physical origin of the angular momentum transport is essential to figure out the dynamics of an accretion disc and its consequences on the planet formation process. The macroscopic feature introduced by self-gravity is the formation of large-scale density fluctuations in the form of a spiral pattern that can be detected and unambiguously identified through high resolution (sub-)mm observations. Our program aims to investigate the presence of spiral density perturbations induced by self-gravity in the Class 0 source IRAS 16293 - 2422B, an ideal candidate as it shows evidence of a compact disc that is thought to be massive enough to be gravitationally unstable. To this aim, we propose to observe the object in Band 3 using an antenna configuration that allows us to resolve the disc and the spiral arms that are expected in this disc due to gravitational instabilities. | Disks around high-mass stars | Disks and planet formation | 2019-02-21T21:42:36.000 |
| 4376 | 2021.1.00262.S | 0 | Directly measuring the progression of infall from the envelope to the disk-forming region of BHR 71 | Infall transforms dense cores into protostars. During the embedded phase of star formation, the evolution of infall determines the final mass of the central protostar as well as the initial condition of the disk and planet formation. Theoretical studies still debate about the types of infall, the "inside-out" or "outside-in" fashions, and the effects of rotation and magnetic fields; only few direct observation of infall exists to constrain the infall process. Previously, we have detected an unambiguous signature of infall, toward an embedded protostar, BHR 71, and modeled the infall kinematics. To trace the progression of infall, we propose here to measure the radial variation of infall toward BHR 71 via multiple transitions of HCO+, empirically probing the infall at different radii, and the resolved emission of complex organic molecules (COMs), tracing the kinematics close to the disk. We will trace the kinematics from the envelope (~1000 au) to the disk-forming region (~30 au), identifying the type of infall and probing the transition from infall to rotation. Furthermore, we will survey the high frequency emission of COMs to complement the previous discovery of COMs. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-10-21T20:14:02.000 |
| 4377 | 2012.1.00352.S | 0 | The fundamental structure of molecular cloud edges: from clumps to photoevaporation | We propose ALMA observations to resolve the fundamental structure (homogeneous vs. clumpy?) of a prototypical UV-illuminated molecular cloud edge. This is a key question to understand the evolution of molecular clouds in general, and how chemical species are formed and excited in UV-irradiated environments. We propose to carry out sub-arcsecond observations of the CO J=3-2 and HCO+ J=4-3 lines towards the interface region of the Orion Bar PDR and the surrounding HII region created by the Trapezium cluster (the closest OB cluster). In addition, we will search for the emission of SH+, SO+ and HOC+ molecular ions. These peculiar species are efficiently produced in the presence of vibrationally excited H2 and/or in the very hot gas, and have previously been detected with single-dish telescopes. They are linked with the presence of key molecules such as OH and CH+ that have been recently mapped with Herschel at poor angular resolution. These species represent the first steps of the hot ISM chemistry. Whether small clumps exist or not, the resulting ALMA spectral-images of the Orion Bar dissociation and ionization fronts (with better spatial resolution than H2 and PAH images in the near-IR) will have profound implications. | Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2015-07-03T14:57:14.000 |
| 4378 | 2023.1.01493.S | 0 | Resolving N2H+(1-0) emission for the first time across the galaxy disk of M100 | We propose to get a sensitive ACA Band 3 map of one of the best tracers of cold, quiescent dense gas, N2H+(1-0) across the nearby, star-forming galaxy NGC4321. This is a well studied nearby galaxy with dynamical features similar to the Milky Way, and a wealth of public molecular lines from ALMA. Combining our detailed knowledge of the physical conditions in NGC4321 from previous work with the rich ancillary data, we will place the most comprehensive observational constraints to date on how the dense gas and its efficiency to form stars, depend on local conditions across a wide range of galactic environments. Given the extensive use of HCN as an extragalactic dense gas tracer, these new N2H+ observations represent a major step forward and will provide a crucial benchmark to quantify how well HCN performs under realistic conditions in a representative external galaxy. This is essential to pinpoint biases in past, present, and future studies that rely on HCN to trace dense gas on the large scales probed in extragalactic studies. We are now in a position to make the first full galaxy, resolved map that will link the two major bodies of work on dense gas: extragalactic and Milky Way. | Astrochemistry | ISM and star formation | 2025-06-28T13:16:57.000 |
| 4379 | 2021.2.00017.S | 9 | Characterizing the least known and most dusty Galactic merger remnant | Red novae erupt in stellar-merger events. We propose to obtain dust continuum measurements of the remnant of the least known red nova, BLG-360, 20 years after the stellar collision. The requested ACA observations in bands 3 and 7 will be combined with contemporary Gemini and SOFIA observations to investigate the full spectral energy distribution (SED) of the object. Modelling of the SED will reveal the dust type and mass in the circumstellar medium, the structure of the remnant (envelope vs disk), and will shed light on its two-decade long evolution. This will allow us to understand BLG-360 as an individual remnant and also as a member of the red nova group. We would like to understand, for instance, why the eruption of BLG-360 was longer and more dusty than other red novae. This project is part of a larger program aiming to explain why and how non-compact stars merge. The observations will inform hydrodynamical models of the common envelope and mergers, a very active field of current theoretical astrophysics. | Supernovae (SN) ejecta, Transients | Stars and stellar evolution | 2023-05-25T14:46:04.000 |
| 4380 | 2024.1.00685.S | 0 | The cold gas and ice chemistry of protostellar hot corinos | The emergence of complex organic molecules in the interstellar medium is a fundamental puzzle of astrochemistry. Observations of these species toward prestellar cores and large-scale protostellar envelopes highlight the importance of the conditions and dynamical evolution of the cold natal environments for the ensuing chemistry. We propose a program to study the link between the chemistry of the gas and ices in the large-scale, cold (10-20 K) protostellar envelopes to that in the small-scale, warm (> 100 K), gas close to emerging protostars. The proposed ACA mosaicing observations of a sample of six known hot corino sources will be complemented by approved JWST ice mapping observations revealing the ice compositions on the same spatial context and contrasted to the gas in the hot corinos traced by a large ALMA program. Together these three sets of observations will provide the first systematic view examining the chemistry of protostellar systems in the gas- and condensed-phases at all size and temperature scales from the cold dark cloud to the scales of the hot corino and emerging protoplanetary disks. | Low-mass star formation, Astrochemistry | ISM and star formation | 3000-01-01T00:00:00.000 |
| 4381 | 2022.1.00359.S | 9 | Star-forming molecular clouds in the XUV disk of M83 | The GALEX satellite discovered a surprisingly large number of bright UV sources (massive star formation) beyond the optical radii (R25) of galactic disks (namely, the extended UV disks, or XUV disks). Despite occurring in the extremely low-density environment, this mode of star formation (SF) is fairly common among local spiral galaxies. Questions arise as to whether these massive stars are forming in (unexplored) molecular clouds and what the gas physical conditions are. We propose to detect and characterize the parental molecular clouds of the massive SF in the XUV disk of M83. This proposal is built on a recent serendipitous discovery of 23 unresolved, CO(3-2)-bright molecular clouds in a 1 kpc^2 region at a galactic radius of 1.24*R25 in the XUV disk. We propose (1) to probe the internal structures of those star-forming clouds by resolving their CO(3-2) emission at a higher spatial resolution, and (2) by determining their gas excitation conditions with deep CO(2-1) observations. We will also (3) confirm the generality of the CO(3-2) clouds in the XUV disk, by mosaicking another 1 kpc^2 region farther away from the galactic center at a radius of 2.15*R25. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2024-03-06T11:03:56.000 |
| 4382 | 2013.1.01192.S | 0 | Spectral Line Survey toward Young High-Mass Protostar Candidate NGC 2264 CMM3 | Spectral line survey is of fundamental importance for astrochemistry and astrophysics, which has brought many new discoveries on target sources and chemical processes. Unbiased comparison of chemical compositions among different sources allow us to make secure discussions on evolutionary trends and/or an origin of chemical diversity. In this proposal, we propose a spectral line survey toward the young high-mass star forming region NGC 2264 CMM3 in Band 7. This source invloves a deeply embedded high-mass protostar(s), which launches a very compact outflow. The 10” region of this source shows a complex physical and chemical structure which resemble the prototypical high-mass protostellar source, Orion KL. For instance, the distribution of HCOOCH3 is apart from the protostar, just as the case of the compact ridge in Orion KL. We observe the chemical compositions and distributions of this infant high-mass protostellar source in an unbiased way, and critically compare them with the Orion KL case. We explore the chemical evolution associated with high mass star formation, and establish a robust base for chemical diagnostics of high mass star forming regions. | High-mass star formation | ISM and star formation | 2016-12-30T22:01:54.000 |
| 4383 | 2021.1.00814.S | 10 | Unveiling the Nature of a Dust-reddened Quasar Hosting a Ten-Billion Solar Mass Black Hole at z=7.1 | Recently, a luminous quasar, J0038, has been discovered at z = 7.1, which hosts a supermassive black hole (SMBH) with at least 10 billion solar masses. Its rest-frame UV continuum shows evidence of strong dust reddening, with a SED suggestive of extinction due to supernova produced dust. This is the only known quasar at z>6.5 with a 10 billion solar mass BH, as well as the most distant dust-reddened quasar. It provides a unique opportunity to study BH-host co-evolution of extremely massive BHs in dusty environment. The proposed ALMA observations will detect the [C II] line and underlying continuum emission, providing accurate systemic redshift and estimate of the star formation rate, FIR luminosity, and dust mass in the host. We will also use the ALMA data to constrain the dynamical mass of the quasar host, to search for signatures of gas outflow, and to study its small-scale environment. The combination of the proposed ALMA data with an approved JWST program as well as proposed HST and X-ray observations will provide a comprehensive view of this unique quasar at multiple wavelengths and scales, shedding light on the connection between the earliest SMBHs and massive galaxies. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-06-15T06:13:57.000 |
| 4384 | 2022.1.01311.S | 346 | Star Formation Beyond the Eddington Limit? 100pc-scale Dust Continuum Imaging in Strongly-lensed Dusty Starbursts | Herschel, Planck, and other submm surveys have shown that dusty star forming galaxies (DSFGs) with SFR >1000 Msun/yr are ubiquitous in the early Universe. Yet, they remain a challenge for theoretical modeling because of complex interplay among gas accretion, star formation, and feedback processes occurring on sub-kpc scales that are beyond observational resolution today. In one case, the Eddington limit is a hypothetical maximum of star formation surface density beyond which stellar feedback regulates and quenches subsequent star formation. Here, we identify 14 Planck-selected gravitationally-lensed DSFGs (z=1-3), with intrinsic luminosities >10^13 Lsun, to obtain high-resolution (0.1") imaging of dust continuum at 870micron/1mm in order to identify possible sites of maximal, Eddington-limited star formation at crucial 100-500pc scales. By comparing with rest-frame optical imaging from HST, we can also constrain the geometry of dust extinction in DSFGs, hypothesized to be patchy and inhomogeneous. Lastly, 0.1" imaging is likely to reveal clumpy, multiply-imaged features that will help refine existing lens models, which are essential for the interpretation of galaxy properties. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2024-02-16T22:14:16.000 |
| 4385 | 2013.1.00152.S | 11 | Hyperluminous Hot DOGs: Hosts to High-Velocity Molecular Outflows? An Early Science Exploration | In this early science program we seek to synergize two major discoveries of the Herschel and WISE missions: 1) the Herschel discovery of massive, high velocity (v~1000 km/s) molecular outflows in ULIRGs, apparently powered by AGN fueled during the gas-rich galaxy merger and 2) the WISE discovery of a class of extremely rare and hyperluminous hot dust-obscured galaxies (Hot DOGs) that may represent a short transitional stage of galaxy merging in which the AGN has partially cleared away the merger’s star-forming ISM allowing an unencumbered view of its mid-IR power. In local ULIRGs the molecular outflows are best traced by rest-frame FIR transitions of OH and H2O. In this pilot study we propose to observe the strongest OH doublet at 119.3 microns (2513 GHz), a ground-state doublet that in ULIRGs shows P-Cygni or pure blueshifted, blue-winged absorption profiles that are unambiguous indicators of outflowing molecular gas. Positive detection of outflows in luminous Hot DOGs would provide synergistic support for the posits of both discoveries: that luminous AGN power the molecular outflows in ULIRGs and that the Hot DOGs are powered by AGN during transitional periods of strong feedback. | Starbursts, star formation, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-08-21T21:31:31.000 |
| 4386 | 2017.A.00054.S | 1251 | ACA Observatory Project: SMC Band 6 CO and continuum mapping | The SMC is an ideal laboratory to study star formation and evolution in a low metallicity environment similar to the early Universe. As a legacy observatory project we propose a large area ACA-only map of 12CO, continuum and H(30)alpha of the North SMC bar, which contains active areas of star formation including the brightest HII region in the SMC, NGC 346 / N 66. This will improve several-fold in resolution compared to any previous single dish millimeter wavelength surveys of the region, providing a valuable resource to the community for future ALMA follow-up of a broad range of science areas. | Magellanic Clouds | Local Universe | 2019-03-05T00:00:00.000 |
| 4387 | 2024.1.00360.S | 0 | A new method to derive the dust opacity spectral index in hot corinos using methanol emission lines | New research suggests that planet formation may start early in the planetary system formation, making it important to study how dust evolves. A valuable tool for tracing grain growth is the dust opacity spectral index (beta), as its dependence on the frequency provide insights on dust properties (size, porosity, composition, etc.). Usually, beta is derived from multi-wavelength dust continuum observations in the optically thin regime and under the Rayleigh-Jeans approximation. Class 0 sources are deeply embedded in their natal environment and the dust is highly optically thick. This leads to underestimating beta, and gives incorrect predictions on grain sizes. We aim to derive and constrain beta, at 60-70 au scales, in two well known Class 0 hot corinos in a direct way using multiple methanol emission lines. With methanol, we derive the dust absorption at different frequencies,from 25 GHz where the dust is more likely optically thin and where we can estimate the contribute of the dust to the line emission, up to 400 GHz. Moreover, the beta dependency with the frequency gives insights on the dust properties. This will be possible thanks to the unique combination of JVLA and ALMA. | Low-mass star formation, Astrochemistry | ISM and star formation | 2025-11-08T20:16:50.000 |
| 4388 | 2015.1.00995.S | 41 | Diurnal Variations in Molecular Species on Io | We request time (90 min total) to observe Io in eclipse, and subsequently coming into sunlight. When Io is in eclipse the SO2 (and likely SO) atmosphere will be collapsed. Only volcanic species are expected to remain. We will observe how and how fast the atmosphere is getting re-established once it comes into sunlight. We will observe the species SO2, SO, NaCl, and KCl. | Solar system - Planetary atmospheres | Solar system | 2018-01-27T22:47:01.000 |
| 4389 | 2015.1.01446.S | 0 | Spatially resolved observation of SiO in the dust formation region around a silicate-poor and alumina-rich AGB star, W Hya | We propose to observe a radial distribution of SiO in a circumstellar envelope of a typical silicate-poor and alumina-rich AGB star, W Hya, to verify that a large amount of SiO gas molecules, a complementary component of silicate dust, remains in the envelope beyond the silicate-forming region. This observation will explain the unexpected silicate-poor and alumina-rich nature of dust shells around many AGB stars with low mass-loss rates and constrain dust formation around silicate-poor stars. We simultaneously observe 29SiO (J=8-7), 12CO (J=3-2), and 13CO (J=3-2) at band 7 to obtain the relative abundance profile of SiO in the envelope. AlOH (J=11-10) and AlO (N=9-8), gas molecules to form alumina dust, and continuum emission are also simultaneously observed. The total observing time is 4.01 hours. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2017-03-01T21:15:18.000 |
| 4390 | 2016.1.01495.S | 30 | Constraining the Mass of the Planet in the Gap Discovered in the TW Hya Disk | We propose to observe the 13CO and C18O J=3-2 line emission towards TW Hya with high spatial resolution and high sensitivity in order to detect a gas gap in the disk. Our ALMA cycle 2 and cycle 3 DDT observations have shown the existence of a gap at the disk radius of 22AU in dust continuum emission. In addition, our cycle 3 DDT multiple-band observations show an enhancement of dust spectral index at the gap, which suggests the gap is likely to be caused by a planet. This proposal aims to constrain the mass of the planet by measuring the depth and width of the gas gap at 22AU. In order to derive the planet mass precisely, we need to know the properties of the gas gap, rather than the dust gap because of the dust filtration. Our cycle 2 observations show that the optically thin C18O line is a good tracer of gas surface density distributions together with the optically thick 13CO line as a tracer of gas temperature. Following our cycle 2 and cycle 3 DDT observations, we challenge to detect the gas gap with high spatial resolution in this proposal. This will be a pioneering study of the formation environment of a planetary system, taking advantage of the TW Hya's proximity. | Disks around low-mass stars | Disks and planet formation | 2018-02-10T15:43:41.000 |
| 4391 | 2015.1.00059.S | 28 | The mass loss history of the "fresh" carbon star TX Piscium - A showcase for stellar evolution | We propose observations of the Circumstellar Envelope (CSE) of the Asymptotic Giant Branch (AGB) star TX Psc, which probably has transitioned from oxygen-rich to carbon-rich very recently, judged by its low C/O ratio and location in the Hertzsprung-Russell diagram. So far, no proper radiative transfer modeling for the CSE of TX Psc could be carried out because of its complexity: Herschel/PACS images of thermal dust show a spherical shell-structure at 17" around the star, while previous CO single-dish observations of TX Psc only confirm CO emission at offset positions about 20" from the star, but do not reveal the detailed molecular gas morphology and kinematics. The dusty shell might be associated with a molecular counterpart, which suggests the formation through a very recent thermal pulse. We want to determine the mass loss history of TX Psc, clarify nature and origin of the shell-like structure around it, and derive stellar wind parameters for subsequent modeling of mass loss and stellar parameters. Observations of the molecular CSE will allow us to constrain the evolutionary status of TX Psc and contribute to our understanding of the transition from O-rich to carbon AGB stars. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-07-17T12:41:30.000 |
| 4392 | 2021.1.00704.S | 25 | Titan's atmospheric asymmetry | This proposal investigates seasonal asymmetry in Titan's atmosphere for late winter by comparing ALMA and Cassini observations. This will test the effect of Saturn's orbital eccentricity on Titan's middle-atmosphere. The two datasets will be separated by half a Titan year and cover comparable late winter phases; southern late winter for ALMA and northern late winter for Cassini, at comparable spatial resolution and precision. CO will be observed in three bands to determine atmospheric temperature structure. HCN, HC3N, and C3H4 will be observed in bands 6 and 7 to determine three key seasonal asymmetry diagnostics. Late winter is a particularly valuable time to perform this comparison as the winter vortex edge will be visible and there will be remnants of the previous season's winter vortex enrichment in the summer hemisphere. Such observations will not be possible for another 15yrs. For the first time, these observations will answer a major outstanding question: are Titan's seasons chemically and physically symmetric? If Titan's atmosphere is asymmetric this will demonstrate the importance of orbital eccentricity on terrestrial atmospheric circulations and chemistry. | Solar system - Planetary atmospheres | Solar system | 2022-10-13T03:43:45.000 |
| 4393 | 2022.1.00311.S | 16 | Feedback from Supernova Remnant on Molecular Clouds: A detailed Study of the Shocked Gas in IC443. | Supernova remnants (SNRs) play a major role in regulating the star formation efficiency and evolution of galaxies. They locally enhance the density of the gas and inject vast amounts of energy and momentum that disturb and disperse their surrounding environment. However, it remains uncertain to what extent molecular clouds and their star formation activity are affected by SNRs, a key aspect in galaxy evolution models. Here, we propose to use ~2 hours of ALMA and ~20 hours of ACA+TP observing time to investigate the ongoing shock interaction between the SNR IC443 and an associated molecular clump (clump G). We propose to map the SiO(2-1) and H13CO+(1-0) emission in Band 3, to investigate the morphology and kinematics of the shocked and dense gas and to constrain the energy and momentum imprinted by the SNR IC443 on clump G. We will also obtain high-angular resolution 3mm continuum map that we will use to investigate the effect of the SN feedback on the star formation activity of the clump. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-09-06T17:54:15.000 |
| 4394 | 2017.1.00520.S | 0 | Revealing the Radial Variation of Grain Growth in the Protoplanetary Disk around TW Hya | We propose to observe the protoplanetary disk around TW Hya in continuum emission at band 4 and 6 with 0.04" resolution using ALMA. Our previous ~3 au resolution observations at band 4 and 6 in ALMA cycle 3 DDT confirmed the existence of multiple gaps and rings, and we also found that the beta index of dust mass opacity is peaked at the most prominent gap at 22 au gap. However, the unoptimized antenna configuration during the observation period caused a systematic error in the CLEANed image, and it is difficult to constrain the radial variation of grain size distribution which can be estimated from beta. The proposed observations are to obtain better uv coverage at longer (>3000k-lambda), where our previous data are sparse. By combining with the previous set, the detailed distribution of the spectral index over the disk can be confirmed. With the observed data, we will discuss the radial variation of the dust growth probably related to the planet formation process including the radial transportation of the growing dust grains and/or the snowline. | Disks around low-mass stars | Disks and planet formation | 2018-12-27T08:01:40.000 |
| 4395 | 2017.1.00379.S | 154 | Physical properties of dense gas in an AGN-driven outflow | Outflows in galaxies play an important role in terminating further star formation by expelling molecular gas, the ingredients of star formation. On the other hand, star formation activity was recently found in an AGN-induced outflow; it is likely caused by gas compression in the outflow. The change in physical properties due to such compression in the molecular gas in galactic outflows are still poorly known. Gas density and the dense gas fraction are especially important measures for the star formation efficiency. Those properties can be best studied in nearby galaxies using molecules with higher critical densities. Here we propose to observe multiple transition lines of HCN in NGC 3256 to study the dense molecular clouds we found in its outflow using the large-velocity gradient analysis. Observing at high resolution in one transition, we will also determine the cloud size and velocity widths. From the physical conditions of the molecular gas, we will assess the outflow's ability to form stars. This will be an important case study for understanding the molecular cloud properties in an AGN-driven outflow, which could lead to a further survey. | Merging and interacting galaxies, Outflows, jets, feedback | Galaxy evolution | 2019-10-16T23:36:46.000 |
| 4396 | 2023.1.00561.S | 0 | Characterizing the protoplanetary disks around young massive stars | Most stars in ALMA surveys of protoplanetary disks have stellar masses less than 2 solar mass. The few existing observations of higher-mass objects have found more massive and structured disks than those around low-mass stars, suggesting a higher incidence of giant planet formation. Hence, evidence is emerging that disks around higher mass stars evolve differently. Unfortunately, past observations of high-mass forming stars mainly targeted evolved objects (>3 Myr). This motivates a more complete survey to understand the disks around younger massive stars. We propose to conduct the first survey of disks around young (<3 Myr) massive (2-4.5 solar mass) pre-main sequence stars, targeting 34 carefully selected disks which will increase the amount of observed disks at this early stage by a factor of 7. This will allow us to provide a complete picture of the protoplanetary disk evolution in high-mass stars, from early ages to the main sequence. In particular, the proposed observations will allow us to study the mass reservoirs and disk sizes at these unexplored young disk stages. This is key for separating between different disk evolution scenarios and giant planet formation mechanisms. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2025-08-17T01:24:37.000 |
| 4397 | 2018.1.00484.S | 0 | From the main sequence to the red cloud: linking the molecular cloud lifecycle to galaxy evolution | The molecular cloud lifecycle, the efficiency of star formation and the coupling of feedback to the ISM depend both on local and global conditions, and strongly affect the global evolution of galaxies, from the main sequence to the red cloud. Mapping the molecular gas on the cloud scale across a broad range of environments is a key step to measure these quantities and understand how the local physical processes contribute to regulating star formation and feedback in galaxies on large scales. We propose to apply the high sensitivity and high angular resolution of ALMA to map the molecular gas disc down to cloud scales in a sample of early-type galaxies, which are in (or have completed) the transition from the main sequence to the red cloud, and study the interplay between small-scale physics and galactic structure. Combined with our previous results on ~20 star-forming main sequence galaxies, we will thus cover the complete evolutionary track of galaxies. This will provide strong constraints on whether galaxy quenching is driven by a cloud-scale inefficiency of star formation or by galaxy-scale processes. | Early-type galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2020-02-16T18:50:08.000 |
| 4398 | 2011.0.00002.SV | 0 | Science verification observation of NGC3256 | Science Verification (SV) is the process by which we demonstrate that ALMA is capable of producing data of the quality required for scientific analysis, i.e. data good enough to be included in the peer-reviewed literature, and by which we fully test all observing modes expected to be available during Early Science (ES). This is achieved by making observations of a small number of selected astronomical objects. This work has been taking place since early 2011. | Merging and interacting galaxies, Galactic centres/nuclei | Galaxy evolution | 2016-06-24T14:02:06.000 |
| 4399 | 2019.1.00120.S | 27 | The chemical origin of CO in diffuse molecular gas | The chemistry of the diffuse interstellar medium is driven by the combined influence of UV radiation and turbulence. This proposal aims at establishing the CO formation route in the diffuse interstellar gas where much of the CO is formed. In diffuse gas HCO+ is the precursor of CO but its origin is still discussed with different routes in UV-driven and in turbulence-driven chemistries. The key for the origin of CO and HCO+ is CO+ that is required exclusively in the UV-driven chemistry and has been previously detected in the ISM only at the outer edges of dense PDRs. Establishing accurately its abundance will close the loop in the CO chemistry. We have selected the two strongest QSOs with deep HCO+ absorption to search for CO+ absorption at 236 GHz. The experiment is set to use the maximum dynamical range to detect CO+ at the level of a few percent of HCO+, much below its predicted abundance if the UV-driven chemistry is the chemical origin of CO. Within a rather short integration, ALMA will allow to pin down the still controversial origin of CO in diffuse molecular gas. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-01-15T17:02:30.000 |
| 4400 | 2017.1.01056.S | 26 | HNC/HCN thermometer in protoplanetary disks | We propose to image the spatial distribution of HNC and HCN across the well-studied protoplanetray disk TW Hya to resolve the HNC/HCN isomeric ratio and calibrate its potential as a tracer of the gas temperature in disks. Based on observations (of prestellar and protostellar sources) and theory, the HNC/HCN ratio is expected to depend predominantly on the gas temperature and it should thus be a good thermometer between 20 and 100 K -- HNC/HCN ratios of ~1 are observed at 10 K, and the ratio decreases at higher temperatures. The disk around TW Hya is one of the most studied protoplanetary disks where both HCN and HNC have been detected previously. It thus offers the ideal template to image the HNC/HCN ratio in a disk with the best known physical conditions. | Disks around low-mass stars | Disks and planet formation | 2019-10-11T16:11:10.000 |
| 4401 | 2012.1.00720.S | 0 | The ``Over-Cooked'' ISM in the Cartwheel Ring Galaxy | Evolved ring galaxies provide unique star forming environments by virtue of their ability to confine the ISM to the rings for 150-400 Myrs, thereby exposing molecular clouds to excessive damage from OB stars, HII regions, and SNe. To explain our observations of the ring galaxy AM0644-741, we proposed its ISM to be "over-cooked", i.e., dominated by small clouds with a large photodissociated HI component. We propose to mosaic the Cartwheel, the archetype ring galaxy, in the 12CO(J=1-0) line using the C32-1 array. The resulting distribution and kinematics of molecular gas in the galaxy, when combined with our extensive ancillary data set, will allow us to (1) measure the molecular fraction in the starburst ring and the local factor(s) that influence it most, (2) determine the possibly non-Schmidt star formation law, expected in the "over-cooked" hypothesis, (3) refine earlier estimates of the ring's Toomre stability parameter, (4) determine the origin of the mysterious spokes, which we expect to detect in the 12CO(J=1-0) line, and (5) detect potentially large reservoirs of CO "dark" H2. Stack averaging our SMA 12CO(J=2-1) observations of the Cartwheel detect the outer ring for the first time. ALMA will have little problem detecting this emission, promising the best view of the molecular ISM in a unique environment. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2015-04-09T12:19:42.000 |
| 4402 | 2016.1.01201.S | 2 | The nature of dark matter in galaxy collisions | Like particle physics experiments in terrestrial colliders, astrophysical collisions can be used to probe the nature of dark matter. Gravitational lensing observations with HST revealed a 1.62+/-0.48 kpc offset between the dark matter and stars of one galaxy moving through Abell 3827. Such offsets are not produced in simulations of collisionless CDM, but are consistent with predictions of self-interacting dark matter. Before these measurements can be regarded as definitive evidence for physics beyond the Standard Model, the experiment must be repeated. Abell 3827s proximity and gravitational lensing makes it the ideal target. VLT/MUSE follow-up revealed additional lensed images around more of its galaxies - but difficult foreground subtraction confuses the lensed image, preventing further progress at optical wavelengths. We propose ALMA observations of molecular gas in CO(2-1), where the foregrounds become transparent. By tracing molecular gas in the lensed images (in particular, the central counter-image), we will constrain dark matters self-interaction cross-section to ~0.1cm^2/g. This will inform present excitement between the astronomy and particle physics communities. | Gravitational lenses, Galaxy Clusters | Cosmology | 2017-11-15T17:35:17.000 |
| 4403 | 2023.1.01519.S | 0 | Mass loss from Red Supergiants. RSGC2 as an essential sample | Massive stars efficiently lose mass at all stages of their evolution, including the red supergiant (RSG) phase. Since RSGs are progenitors to type II-P supernovae, how and how much mass is lost significantly influences the supernova explosion and the remnant. The amount of mass ejected during the RSG phase is, however, still poorly constrained. The mass-loss rate prescriptions used by stellar-evolution models are based on stellar luminosity but are uncertain by up to 4 orders of magnitude for a given stellar mass. Current empirical estimates are largely based on dust measurements, whereas gas dominates the mass loss by about two orders of magnitude. We propose to observe all RSGs in the coeval open cluster RSGC2, amounting to a sample of 14 RSGs with similar initial masses and chemical compositions. We will derive gas mass-loss rates for these RSGs and provide an additional test to the available mass-loss prescriptions. Since the sample includes 10 late-type RSGs with likely high mass loss, this is an essential study to complement our current knowledge. We will also measure the currently unknown wind expansion velocities and test the current wind-driving scenarios for RSG outflows. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2025-09-02T13:44:48.000 |
| 4404 | 2018.1.00635.S | 129 | Excitation conditions of the diffuse gas traced by [CI] in main sequence galaxies at z~1.2 | Atomic carbon CI has been proposed as a tracer of cold gas in galaxies in alternative to dust and CO. To date, only lensed SMGs and QSOs are [CI]-detected at high z, completely missing the bulk of the normal main-sequence (MS) population. Thus, we started an ALMA survey to detect [CI](1-0) in MS galaxies at z=1.2, partially covered in CO(2-1) and CO(5-4). First results confirm that [CI](1-0) is an excellent gas tracer and that MS galaxies are offset from starbursts (SB) in the IR vs [CI](1-0) luminosity plane, while being 4x less CI rich. We now aim to study the excitation conditions of the gas traced by CI observing the [CI](2-1) transition. In 11.5 hours of Band 7, we will (1) derive the excitation temperature Texc~[CI](2-1)/[CI](1-0) for 7 sources with [CI](1-0) and dust continuum detection from our survey; (2) study systematic differences among gas conditions in MS galaxies and SMGs/QSOs/SBs; (3) evaluate the dust temperature as a proxy for Texc, a common assumption with limited empirical support; (4) finalize a comprehensive analysis in a sample of well studied MS galaxies by comparing [CI](1-0), [CI](2-1), CO(2-1), CO(5-4), and CO(7-6) (obtained while observing [CI](2-1)). | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2020-07-01T09:36:21.000 |
| 4405 | 2016.1.01029.S | 17 | Chemical Composition of Molecular Clouds in the Nearby Metal-Poor Galaxy NGC6822 | In metal-poor environments, chemical compositions of molecular clouds are different from that in our Galaxy. Based on our recent observations of the three low-metallicity galaxies, the LMC, IC10, and NGC6822, with the single dish telescopes, we found characteristic features of chemical compositions in metal-poor environments. Those are enhancement of CCH and deficiency of CH3OH, both of which originate from the low abundance of dust grains. This result would constitute an important base for studying chemical compositions of low-metallicity galaxies including distant galaxies, and hence, detailed verifications are necessary. In the above observations, the distances to IC10 and NGC6822 are much different from that of the LMC. For fair comparison of the molecular-cloud scale chemical compositions among these galaxies, we need to observe IC10 and NGC6822 at a high angular resolution. In this program, we observe NGC6822 in various molecular lines in Band 3 to derive the 10 pc scale chemical composition, which can be compared directly with the LMC result. Considering the growing importance of astrochemistry in extragalactic studies, our program is of fundamental importance. | Dwarf/metal-poor galaxies | Local Universe | 2018-08-13T11:48:21.000 |
| 4406 | 2017.1.00893.S | 224 | SUPER-ALMA v2: gas fractions and depletion timescales in AGN hosts at z~2 | An unbiased study of the gas content of AGN host galaxies is fundamental to: 1) constrain the triggering mechanism of AGN activity; 2) quantify the impact that AGN outflows may have on the gas reservoir of the host. We propose to combine CO(3-2) ALMA observations with our on-going SINFONI/VLT Large Programme (SUPER, 280h) on an unbiased sample of AGN at z~2. While SINFONI allows to map ionised gas kinematics (e.g. [OIII]), the CO(3-2) observations will complete the picture, sampling the molecular gas phase of the interstellar medium. This program has been already awarded time in Cycle-4, and we ask to complete the ALMA follow-up of the full SINFONI sample which is crucial to sample the full range of AGN properties (Lbol, Eddington ratios, presence of outflows and their energetics) to make significant progress in understanding the physical origin of any difference in the gas content of AGN hosts compared to inactive galaxies. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2019-03-29T16:05:30.000 |
| 4407 | 2023.1.01520.S | 0 | Constraining the dust SEDs of highly obscured strongly star-forming galaxies | We propose Band 9 and 4 observations of 298 sub-mm galaxies from an ALMA Band 7 continuum survey in the UDS field. This large sample of sub-mm galaxies is a complete and unbiased flux-limited sample (S_870>4mJy) across ~0.9 deg^2 survey field. The proposed Band 9 + 4 data, together with existing high-quality Band 7 photometry, will constrain the dust SEDs with an uncertainty of just 5% in T_d and 15% in L_fir (currently a factor of ~1.2-1.4 and 1.5-10, respectively), as well as reliably constrain dust emissivity index (~5sigma) which will minimise systematic uncertainties in the derived dust (gas) masses. With a large sample of well-constrained SEDs we will identify bivariate trends in L_fir, T_d, and redshift by binning the sample (~50 sources per bin) and: 1) test if there are structural differences in the dust regions of sub-mm galaxies at different redshifts; 2) address whether high-redshift sub-mm galaxies are systematically cooler than local ULIRGs and if this is due to lower M_dust and/or more compact sizes; 3) assess the composition of the dust grains and their average chemical enrichment, which may indicate physical changes in the ISM properties in SMGs across z=2-4. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-08-23T13:38:23.000 |
| 4408 | 2016.1.01245.S | 175 | Laying the groundwork for future ALMA direct magnetic field detection | No observations have ever directly measured magnetic field strengths in young low-mass protostars. Observing the Zeeman effect in transitions of paramagnetic molecules, especially CN, is one of the best prospects for making such measurements due to such molecules' high Zeeman coefficients. However, CN and other such paramagnetic molecules have rarely been observed in the envelopes of Class 0 protostars at ~arcsecond resolution. Therefore we embark on a snapshot survey to find potential candidates for Zeeman detections within the inner envelopes of these sources. We propose to observe the 10 brightest Class 0 protostars in the Perseus, Taurus and Rho Oph molecular clouds. With this survey we will pinpoint which sources have the brightest lines that may be used for future Zeeman observations. Such observations will provide the first direct magnetic field measurements of low-mass protostars. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-02-24T15:25:05.000 |
| 4409 | 2023.1.01313.S | 0 | Mapping star formation at cosmic noon: making the most of ALMA Cycle 8 data | In Cycle 8, we obtained >20hrs of high-resolution CO(J=3-2) observations of a star-forming galaxy at z=2.24, SHiZELS-14. Matched-resolution data in H-alpha (from SINFONI), UV (from HST), FIR continuum (ALMA) and the radio continuum (VLA) already exist. Unlike previous targets resolved by ALMA at this redshift, which tend to be ultra-luminous infrared galaxies with compact dust continuum emission, SHiZELS-14 displays extended dust emission, with well-resolved UV and H-alpha emission, providing a unique opportunity to map star formation and star formation efficiency at cosmic noon. Interestingly, the CO intensity map displays a very different structure to the ALMA 260 GHz map. The central peak visible in the dust continuum (assumed to trace star-formation) is not seen in CO(J=3-2) (which should trace molecular gas), suggesting high central star-formation efficiency. However, strong dust temperature gradients (e.g. driven by compact star formation) can affect the mapping of FIR emission to SFR. We hence request 3 hours of observations mapping dust continuum at shorter wavelengths, to model the dust temperature gradient accurately and hence map star formation efficiency robustly. | Starbursts, star formation | Active galaxies | 3000-01-01T00:00:00.000 |
| 4410 | 2015.1.01131.S | 10 | Mapping Neutral, Ionised and Molecular Gas in a z=2.35 Galaxy | An important missing piece in the puzzle of galaxy formation is to relate the neutral atomic gas, molecular gas and the stars in galaxies. Damped Lyman-alpha Systems (DLAs) quasar absorbers are galaxies selected purely by HI gas and are associated with the reservoir of fuel available for star formation. Star formation is believed to occur in molecular clouds, so that DLAs are expected to contain molecular gas. Here we propose to observe in CO(3-2) a unique target, the galaxy host with the highest measured SFR of all DLAs. What makes this z=2.35 target especially attractive is that detailed information is already available about its H I and H_2 column densities and neutral-gas metallicity from high-resolution VLT/X-shooter spectra, and about the ionised-gas metallicity and kinematics from VLT/SINFONI integral field unit observations. The goal of this 'pilot' project is to map the molecular component and estimate the total gas mass of the system. This will provide the first CO emission detection in a DLA at z>1. In the future, this pilot project can be extended to a larger sample of DLA galaxies with SINFONI observations already in hand and with comparable expected CO fluxes. | Damped Lyman Alpha (DLA) systems | Cosmology | 2017-08-10T17:23:37.000 |
| 4411 | 2019.2.00139.S | 10 | Investigating Diffuse Molecular Gases in the Strongly Barred Galaxy NGC 1300 | This proposal challenges the long-standing problem in barred galaxies that is why star formation (SF) in the bars is suppressed. Recently we made CO(1-0) observations towards the arm and bar of a nearby prototype strongly barred galaxy NGC1300 with Nobeyama 45-m telescope and ALMA 12-m array which has no sensitivity on extended diffuse molecular gases. We find that only ~40 % of the total CO flux is detected with the 12-m array in bar region. This suggests that a large amount of diffuse molecular gas exists in the bar, and and that it could be the key to understand the SF suppression. Therefore, investigating why a large amount of diffuse molecular gases exists (i.e., do not become GMCs) in the bar is important. Based on our hydrodynamical simulation of NGC 1300, diffuse gases are distributed filamentary, which is missed in the 12-m array data. We thus propose CO(1-0) observations toward NGC 1300 with 7-m array to make the total CO emission (GMCs + diffuse gases) map at 50 pc resolution combining the 12-m data, in order to detect the filaments, and to compare the properties of the diffuse molecular gases between the arm and bar. | Starbursts, star formation | Active galaxies | 2021-06-23T17:03:52.000 |
| 4412 | 2016.1.00964.S | 1 | Size ratios in Kuiper Belt Binaries | The Kuiper Belt presents a high fraction of bodies in binary or multiple systems. Different mechanisms have been proposed to explain binary system formation (co-formation, rotational breakup, capture, collision...), which can help to characterize evolutionary processes of the outer Solar System. Determining the physical properties of each member in a binary system (composition, density, shape and size) is essential to understand how the system may have formed. Thanks to the sensitivity and resolution of ALMA we will obtain the first resolved thermal maps of binary Kuiper Belt Objects (beyond Pluto), allowing us to derive independently the size and albedo of each component of a system using the radiometric method. Those results will help us to determine the size ratio and the albedo difference within 3 KBOs binaries, which we will relate to formation mechanisms. In addition, the improved size measurements will be used to derive more accurate density estimates. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2018-08-12T10:14:39.000 |
| 4413 | 2016.1.01385.S | 59 | Resolving AGN accretion-ejection structure: evolving torus at high accretion rates | The AGN obscuring torus, the key structure in the AGN mass accretion process as well as in the unification scheme, is finally being spatially resolved with the high angular resolution capability given by long-baseline interferometers both in the infrared IR and sub-mm. These observations, we believe, are now quite drastically changing the picture --- we argue here that the torus seems both obscuring and outflowing, probably due to the radiation pressure from the central engine, and becomes more widely open when the central mass accretion rate gets higher. This was theoretically argued to some extent, but now being directly observed. Here we propose to test, or otherwise falsify, this new picture both morphologically and kinematically, first using a small sample of the brightest AGNs. If confirmed, this will provide critical clues for the torus physical nature, its luminosity evolution, and effects on the host galaxy. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-10-13T20:35:44.000 |
| 4414 | 2011.0.00405.S | 0 | A survey of strong absorption lines at z=0.89 toward PKS1830-211 | The z=0.89 (sub)mm molecular absorber toward the quasar PKS1830-211 offers the unique possibility to explore the molecular content in the disk of a galaxy with an age of less than half the age of the Universe. In this ALMA Early Science proposal, we propose to observe the strong absorption lines of most common interstellar molecules, in order to determine the structure and composition of the gas along the different lines of sight toward the lensed images of the background quasar. The detection of a large number of molecular species will demonstrate the capabilities of ALMA to study galaxies in the distant Universe and accurate measurements of their fractional abundances will provide insights into the basic interstellar chemistry in the disk of a z=0.89 galaxy. | Galaxy structure & evolution, Galaxy chemistry | Galaxy evolution | 2013-10-19T12:40:13.000 |
| 4415 | 2023.1.01527.S | 0 | A comprehensive molecular gas study in the CO Arc region in the Large Magellanic Cloud | Observational studies in low-J CO lines have been widely used to indirectly trace H2 gas mass in the Milky Way and extragalactic environments. However, the behavior has a high environmental dependence and is not fully constrained observationally. In the Large Magellanic Cloud (LMC), "CO Arc", a large-scale structure spanning ~2 kpc, is peculiar in that the CO emitting region is much smaller than the other regions with respect to the total H2 material derived from space telescope continuum data. Unlike its nearby region, the active star-forming molecular ridge, molecular clouds in CO Arc are not currently being compressed by HI gas, which is likely one reason for not enhancing the CO luminosity. With this program, we will obtain an extensive CO map of the CO Arc region with a field coverage of ~0.26 deg^2 (~1.9 x 10^5 pc^2) using the ACA stand-alone mode. We combine large archival surveys in the LMC and Small Magellanic Cloud to get a closer look at the factors changing fundamental physical quantities of molecular clouds, such as the size-linewidth relation and the amount of CO dark gas in the Local Group. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2025-09-24T18:54:12.000 |
| 4416 | 2015.1.01362.S | 17 | ALMA Imaging of the Star Formation Process at the Historic Peak | We propose to image the [CII] line emission and underlying continuum in a selection of 8 redshift 1-2 galaxies that we previously detected in [CII] with our ZEUS spectrometers. We have used the [CII]/FIR continuum ratio to measure the FUV field strength, hence spatial extent of star formation in 24 z~1-2 galaxies. Our measurements indicate moderate intensity star formation extended to >5 kpc scales for SF dominated systems. This is likely the result of Schmidt-Kennicutt law star formation in thick molecular "disks". This "quiescent" mode of starformation may be dominant for highest L(FIR) galaxies in this epoch, in sharp contrast to the intense major merger induced starbursts found in local ULIRG galaxies. We propose to test our conclusions by resolving the starformation activity in [CII] with ALMA. We also hope to probe the fraction of the [CII] emission that arises from AGN-NLR/XDRs with the high resolution imaging. This is a resubmission of program that was approved (top 10%) Cycles 0 and 1 and Cycle 1 rolled over into Cycle 2, but still not carried out. The program is based on following up ZEUS-1/2 detections of the [CII] line from redshift 1 and 2 systems | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2017-12-15T01:15:44.000 |
| 4417 | 2018.1.00525.S | 323 | Linking large- and small-scale organic chemistry in Solar-type protostars | The relationship between the large-scale (1000's of AU) and small-scale (100's of AU) organic chemistry in protostars is poorly understood. With this proposal we aim to answer: does the large-scale organic chemistry in protostars develop into a similar chemical composition on the small scales where disks and planets form? We previously conducted a survey of complex organic molecules (COMs) towards 16 Class 0/I low-mass protostars with the IRAM 30m telescope, primarily probing large-scale outer envelope material. We now propose to observe 8 of these protostellar sources with ALMA at sub-arcsecond resolution, corresponding to spatial scales of ~100 AU. We will evaluate the relationship between inner and outer envelope COM abundances, placing constraints on the degree of reprocessing vs. inhertance as material falls inwards to the disk-forming region of protostars. Moreover, we will compare the relative CH3CN, CH3OH, and HC3N ratios in protostar inner envelopes with the values measured in disks to obtain constraints on the degree of chemical reprocessing during disk formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-11-09T16:07:52.000 |
| 4418 | 2011.0.00539.S | 0 | Lensing Properties of the Brightest Herschel-Selected Submillimeter Galaxies | In the past year, Herschel has revolutionized our understanding of submillimeter galaxies (SMGs), the most intensely star-forming galaxies in the early universe. Detailed studies of SMGs are important, as they represent the short, bursty phases of star formation at high redshift in which a large fraction of the stellar mass in massive galaxies is assembled. This program will closely investigate one of the most unexpected findings in large area Herschel surveys, the discovery of very rare (1-2/deg^2), extremely bright submillimeter sources, which exceed the brightness of SMGs by up to an order of magnitude or more. This population of extremely bright SMGs was previously largely unknown (due to the insufficient areas probed by ground-based submm surveys), but adds a substantial bright tail to submm number counts. Initial studies of a few, selected sources indicate that most of them are SMGs magnified by gravitational lensing, with a small contribution of blends of multiple SMGs within the large Herschel beam. This is consistent with predictions from our models of lensed SMG counts. However, our models also show that up to ~23% of these bright sources may be unlensed starburst galaxies. Such extreme SMGs would be consistent with star formation rates exceeding 10000Msun/yr, which would severely constrain models of the early evolution of massive galaxies in their most active phases. Targeting a complete, flux-limited sample of the 30 brightest southern SMGs in the HerMES survey, we here propose to use <0.5" resolution submm imaging with ALMA to systematically constrain our models of the lensing statistics and magnification factors, to determine the fractions of lensed, blended, and extremely bright unlensed sources among the brightest high-redshift Herschel sources, and (using the ample ancillary data in HerMES) to constrain the physical properties of these enigmatic systems. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2013-09-21T19:56:00.000 |
| 4419 | 2013.1.00259.S | 2 | Resolving the characteristics of QSO and optically obscured SMG pair in BR1202-0725 at z=4.7 | We request for 8.4 hours of ALMA cycle2 observation time as to detect for HCN(6-5) and HCO+(6-5) line for the first time from the pair of a quasar and an optically-obscured AGN in BR1202-0725(z=4.69) system. One of the fundamental studies in galaxy formation and evolution is to understand how massive galaxies have formed. And quasars and SMGs in high-z are likely to represent the archetypes of present-day massive galaxies, but the exact fuelling mechanism is yet well-understood. A good probe to understand this is to use dense gas tracer of HCN/HCO+ as they are tightly correlated with star formation rate. BR1202-0725 consists of one optically-invisible SMG/quasar pair and two Lyman-alpha emitters near the quasar. This system will be the most ideal object to probe dense gas properties in different stages of galaxy evolution. With the proposed observation, the immediate objects are : i) to characterise the dense gas tracers in the BR1202-0725 for the first time ii) to produce radiation field models of SMG and the quasar in BR1202-0725 groups. Even a non-detection would provide the strongest limit on dense molecular gas mass fraction of < 5%. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2016-12-04T23:56:06.000 |
| 4420 | 2023.1.01219.S | 0 | Resolved molecular cloud properties in the nearby extreme starburst center of NGC1365 | We request 0.1" resolution observations of the CO(2-1) emission from the gas-rich (1e10 Msun) star-bursting (SFR~5 Msun/yr) center of NGC1365, improving upon existing 0.3" resolution data. We will contrast this extreme bar-fed center to the Milky Way (MW) center to gain urgently needed insights into the evolution of central molecular zones (CMZs). NGC1365s CMZ is in many ways a massively scaled-up version of the MW CMZ and its more face-on orientation is ideal to study the different processes at play. The 10pc resolution data will allow us to address the following open questions: (a) Are the molecular clouds in NGC1365's CMZ different from those found in the MW CMZ? What prevents star formation in the central 1 kiloparsec? This will test the importance of local and large-scale processes setting cloud properties. (b) Where and how are massive star clusters forming in the CMZ? NGC1365's CMZ harbors 3x more super star clusters than the nearby galaxy merger Antennae. (c) Is there evidence for molecular gas feeding of the central supermassive black hole? Does the relation between black hole mass and bulge stellar mass hold? | Galactic centres/nuclei | Active galaxies | 2025-02-01T02:12:16.000 |
| 4421 | 2018.1.01035.T | 40 | Direct sublimation vs. gas-phase synthesis: A Comet TOO proposal | Comets contain ice, dust and debris left over from the formation of the Solar System. Having remained in a relatively quiescent state ever since, their compositions provide unique insights into the thermal and chemical properties of the protosolar disk and prior interstellar cloud. Detections of complex organic molecules in cometary comae are becoming routine using single-dish mm-wave observations, but the common assumption that these species originate in the cometary ice is largely untested. Our latest chemical/hydrodynamic coma models point to gas-phase chemistry as a possible origin for some of these species. We propose to use ALMA to map the distributions of HC3N, NH2CHO, CH3CN and other molecules (including known extended source species) in a bright target-of-opportunity comet, to reveal whether these species arise directly from the sublimation of cometary ice or whether they are instead synthesized as products of gas-phase chemistry in the coma. In case of only a faint comet in Cycle 5, we will focus on mapping the distributions of H2CO, HNC (and other abundant species) to elucidate the nature of their extended coma sources and compare to previous (limited) mapping results. | Solar system - Comets | Solar system | 2021-01-10T15:22:41.000 |
| 4422 | 2017.1.01108.S | 64 | Molecular Line Diagnostics in Two Early-Type Galaxies | We propose to observe a suite of high-density molecular line diagnostics at ~ 2" to 3" resolution in NGC 4526 and NGC 7465, two nearby early-type galaxies. The galaxies are a Virgo Cluster member with dynamically relaxed gas (significantly processed by the intracluster medium) and an interacting galaxy in a small group. They are also known to have some unusual FIR fine structure line ratios and some unusual single-dish molecular line ratios. Here we focus on CS, CH3OH, HCN, HCO+, HNC, and 13CO transitions, at good enough angular resolution to differentiate the galaxy nuclei from their disks. The line ratios from these transitions will give greater insights into the properties of their molecular gas and how their ISMs have been processed; in addition, we will test a suggestion that CS/HCN may serve as a metallicity indicator in molecular gas. In general the early-type galaxies offer a broader perspective on the ISM than can be obtained from late-type galaxies alone. | Early-type galaxies, Galaxy chemistry | Galaxy evolution | 2019-05-02T18:41:04.000 |
| 4423 | 2021.1.01319.S | 145 | The dark side of the Web of the Giant | Theory predicts that supermassive black holes (SMBHs) at z>6 should form and evolve within the densest environments at that time. These environments are expected to be traced by Mpc-sized galaxy overdensities, but the observational evidence is still disputed. Among all QSOs at z>5.7, the field around the z=6.31 quasar SDSSJ1030+0524 features the best multi-band coverage, which allowed the first discovery of a >Mpc-scale large scale structure (LSS) around a SMBH at cosmic dawn. We propose to obtain mm spectra with ALMA and search for [CII]158um emission in 16 candidate and confirmed LSS members. This approach has proven to be superior in terms of redshift precision and time investment to optical spectroscopy with 8-10m class telescopes. With the proposed sensitivity, we will secure [CII] detections in all targeted sources that belong to the overdensity, and expect to triple the number of known LSS members. This will i) tremendously improve our knowledge of the overdensity level, volume and mass of this unique structure, and ii) allow the first statistical study of the physical properties (total SFR, dust mass, and possibly dynamical mass) of its member galaxies. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2023-12-20T19:35:39.000 |
| 4424 | 2015.1.01478.S | 40 | Probing Formation of Keplerian Disks around First Hydrostatic Core Candidates | We propose ALMA observations toward protostellar candidates in the young cluster Serpens Main in 12CO and C18O 2-1 lines and 1.3-mm continuum emission. Our previous SMA mosaicing observations toward this region show compact 1.3-mm dust continuum emission and 12CO outflows associated with them. These protostellar sources identified with our SMA observations are mostly associated with infrared point sources detected by Spitzer and Herschel observations. Several 1.3-mm sources, however, do not have any counter part in infrared wavelength even at 70 um, suggesting that they are in very early phase of evolutional sequence. Detailed observations toward those compact 1.3-mm sources without 70 mu counterpart enable us to investigate how the dynamics seen in protostellar phse develop from the beginning of the star formation. | Disks around low-mass stars | Disks and planet formation | 2017-09-06T18:59:34.000 |
| 4425 | 2018.1.00739.S | 10 | Dancing with the stars: a binary AGN in the ULIR radio galaxy 3C459 | Since the '80s it has been suggested that at the end of a merger phase, some galaxies may contain two supermassive black holes (SMBH) in orbit around each other. However, despite significant efforts, binary systems of active BHs turned out to be rather rare and/or elusive objects: only a few kpc-scale dual AGNs have been confirmed. We serendipitously discovered a dual AGN in the ULIRG radio galaxy 3C 459 (z=0.22) as part of a survey of powerful radio sources with the MUSE optical integral field spectrograph. The system is formed by a radio-loud AGN and a heavily obscured quasar separated by 4.5 kpc (1.2"). The quasar produces a spectacular ionization bicone, illuminating the gaseous tidal features, relic of the recent merger, up to a distance of 80 kpc. We propose to map with ALMA the CO(1-0) emission line at high resolution (0.2") enabling us to explore the gas properties insensitive of the severe dust obscuration affecting the optical data. This will offer us the extraordinary opportunity to explore the role of the molecular gas in the fueling and feeback cycle of two simultaneously active BHs and to progress in our understanding of these rare objects. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2021-01-25T12:01:32.000 |
| 4426 | 2015.1.00199.S | 46 | Proving the AGN feedback in the extremely IR-bright Dust Obscured Galaxies | We aim to reveal the relation between the SF activity and the molecular gas outflow regarding the AGN positive/negative feedback, in the extremely IR-bright Dust Obscured Galaxies (DOGs) through the observations of 12CO (J=4--3), 12CO (J=2--1) as well as continuum observations. The extremely IR-bright DOGs are a key population to understand the growing phase of the co-evolution between galaxies and supermassive black holes. Investigating how the molecular gas outflow affects the SF activity in the IR-bright DOGs is crucial to tackle the mystery of the co-evolution behind the dust. Combining the latest SDSS data with WISE data, we discovered 65 extremely IR-bright DOGs over the largest survey footprint so far. Among them, we discovered four peculiar objects that show a clear outflow associated with ionized gasses ([OIII]) outflow in their optical spectra, although whether or not the neutral molecular gasses are also associated with outflow. For them, we will investigate the spatial distribution and of dense and diffuse molecular gas as well as velocity distribution. In addition, we will investigate their SFR map derived from far-IR luminosity based on continuum data. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2017-12-27T13:45:20.000 |
| 4427 | 2019.1.00847.S | 473 | A Complete Survey of Protostellar Disk Gas and Dust Structure in Taurus | Recent findings of substructures in the protoplanetary disks of nearly every 1-5 Myr old pre-main sequence star observed with high enough spatial resolution suggest that these disks may already have undergone a significant amount of planet/planetesimal formation. If so, then younger, <1 Myr, protostellar disks likely better represent the initial disk conditions before significant dust processing or planet formation has occurred. To date, however, there have been few large samples of protostellar disks observed with high resolution (<0.5") in both gas and dust to study their structure. Here we propose to observe every embedded protostar in Taurus. We will map their disks with 870 micron continuum and spectral line observations at ~0.3" resolution to determine the geometry of the circumstellar material, and couple our observations with existing VLA 9 mm observations of similar resolution to constrain the maximum dust grain sizes in the disks and search for evidence of the onset of planet formation at early times. The proposed observations will allow us to put together a comprehensive picture of the initial conditions in disks, from which all subsequent planet formation will proceed. | Low-mass star formation | ISM and star formation | 2023-05-04T19:26:33.000 |
| 4428 | 2015.1.01289.S | 657 | Bulge Asymmetries and Dynamical Evolution (BAaDE) II | A radio survey of red giant SiO sources in the inner Galaxy and Bulge is not hindered by extinction. Extremely accurate stellar velocities (<1 km/s) and positions are obtained with minimal observing time per source. Our aim to detect up to ~35,000 SiO maser sources will yield numbers comparable to optical surveys, but with the additional strength of a much more thorough coverage of the highly obscured inner Galaxy. The number of sources will be large enough to trace structures and minority populations and their velocity structure is to be compared with kinematic structures seen in molecular gas, complex orbit structure in the bar, or stellar streams resulting from recently infallen systems. Modeling of the bar and bulge dynamics will be done using this new kinematic information in the inner Galaxy region. Our survey will also yield sufficiently luminous SiO masers suitable for follow-up Galactic orbit and parallax determination using VLBI. We are successfully observing with our calibration scheme using the VLA at 43 GHz and ALMA Cycle2 pilot observations demonstrate excellent feasibility at 86 GHz. We here propose to expand the survey with ALMA in the Southern Bulge. | Surveys of galaxies, Galactic centres/nuclei | Galaxy evolution | 2017-04-26T20:59:31.000 |
| 4429 | 2017.1.00771.S | 51 | Adjusting the Reception of The Antennae: A Clear Look at GMCs in a Major Merger | We propose to map the nearest major merger, The Antennae, in CO (1-0) and (2-1) at giant molecular clouds scales (~40pc). The Antennae is a great proxy for merging galaxies at moderate redshifts allowing us to study how small scale structures combine to form unresolved structures. Using the proposed observations, we will build a catalogue of GMCs with measured properties, study the CO(2-1)/(1-0) line ratio at small scales, measure the CO-to-H2 conversion factor, determine how much molecular gas is ready to form stars and which CO line is tracing the star forming gas better. These maps will be the first observations to fully cover the system including all flux recovered which only ALMA can provide. | Merging and interacting galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2019-10-31T09:49:52.000 |
| 4430 | 2016.2.00197.S | 21 | Tracing the Recycling of Intergalactic Gas as it builds Massive Galaxies | We have used the C/N/O far-IR fine-structure lines to characterize obscured star formation in galaxies at the z~1 to 5 historic peak. We discovered that star formation in many of the most luminous galaxies in this epoch extends over several kpc scales, likely following a quiescent Schmidt-Kennicutt law in thick molecular "disks". These disks are likely formed and replenished by gas that falls in from the cosmic web. We aim to test this hypothesis by detecting overdense regions of the circum-galactic medium (CGM) where infalling gas mixes with metal-rich gas driven out of the galaxy by star formation or AGN activity. This gas is likely ionized and detectable in the [CII] line even if abundances are depressed by factors of >3. Since the emission is extended over 100 kpc-sized regions, it is best detected with the large field of view of the ACA. Our best candidate for detecting CGM [CII] emission is the very luminous star forming galaxy, W2246-0245 at z = 4.6 (Band 7) where sensitivity is high, and the field of view is large. A detection would strongly support models of gas recycling through infall and outflows in massive star forming galaxies in the epoch of galaxy formation. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2018-08-19T16:21:48.000 |
| 4431 | 2016.1.00234.S | 49 | Stars on the Verge - Thermal Continuum Tomography of the Nearby Red Supergiant SN II progenitor: Antares | The nearby red supergiant and SN II progenitor Antares (alpha Sco A) is an ideal target for studying the mechanisms that extend the atmospheres of M supergiants and drive the poorly understood process of mass loss. At mm/sub-mm continuum wavelengths, Antares extends one of the largest angular diameters of all stars in the sky, meaning that it is one of the few stars that can currently be spatially resolved with ALMA. With the long baselines, ALMA is now able to probe the crucial layers above the photosphere where much of the energy is injected into the stellar outflow. We propose to use ALMA at its maximum spatial resolution to perform thermal continuum tomography which will probe through the layers of the chromosphere and molecular outer atmosphere (MOLsphere) for the first time, permitting the temperature structure to be mapped and the energy balance determined. The proposed observations will also permit a search for temperature inhomogeneities in the inner atmosphere which may be manifestations of magnetic activity or large convection cells. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-09-11T18:31:20.000 |
| 4432 | 2018.1.00570.S | 5 | Spectroscopic Confirmation of Galaxies in the Reionization Era | We propose for 2.5 hr of ALMA Band 6 spectroscopy to confirm the redshifts of at least one in a close pair of galaxies. Both galaxies have a photometric redshift of z~7.4, and a spectroscopic detection of the Lyman break consistent with the photo-z, robustly placing them deep in the epoch of reionization. While Lyman-alpha has long been the spectroscopic redshift tracer of choice, deep observations with 10m telescopes are showing that this line is not detectable for the vast majority of galaxies at z > 7, possibly due to scattering by neutral gas in the intergalactic medium (IGM). Lacking Lyman-alpha, the [CII] 158 micron line is the best alternative, and it is now detectable with the advent of ALMA. In the future, we plan to use ALMA to confirm the redshifts for a large sample of z > 7 galaxies -- here, we propose a pilot study to confirm at least one of a close pair of galaxies. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-09-11T15:24:30.000 |
| 4433 | 2015.1.01243.S | 49 | Molecular gas in debris disks around young A-type stars | According to the current paradigm of circumstellar disk evolution, gas-rich primordial disks evolve into gas-poor debris disks composed of second-generation dust. The transition between these phases is little understood. Recently, a measurable amount of gas was found in a few bright debris disks around A-type stars. The origin of gas in most of these systems is thought to be secondary. Nevertheless, we know at least two systems that harbor huge amounts of primordial gas. The existence of gas in debris disks has an important impact on disk evolution models and the timescales for giant planet formation. Here we propose an ALMA survey for the brightest and most massive debris disks around young A-type members of nearby moving groups and associations. By observing their 1.3 mm continuum emission and J=2-1 line of 12CO, 13CO, and C18O, we will measure their dust/gas content and study the dust/gas morphology. Using these results we will 1) decide whether the gas is primordial or secondary; 2) determine the incidence of different types of gaseous debris disks around young A-type stars; 3) analyze the production and evolution of secondary gas in young debris disks. | Debris disks | Disks and planet formation | 2017-06-08T09:23:43.000 |
| 4434 | 2015.1.00149.S | 46 | Testing a Chemical Model to Probe Supermassive Black Hole Accretion | The physical mechanisms for forming the obscuring dust tori at the center of AGNs is a fundamental open question in astrophysics. At the center of our Milky Way, a similar question is whether the well-known 2-4 pc, ring-like molecular circumnuclear "disk" (CND) is dynamically captured from cooler large-scale gas clouds, or is a long-lived gas/dust ring supported and heated by strong radiation field from the central stellar cluster. In this project, we propose a focused ALMA experiment to detect DCN and DCO+ at where the exterior gas streams may be merging into the hot CND. These deurated species form efficiently when cool molecular gas condenses onto dust grain surfaces, and are destroyed rapidly in the hot gas phase. Observations of these molecules have been widely used as chemical clocks to diagnose the evolutionary status of accretion flows surrounding OB cluster-forming hot molecular cores. This project aim to address the gas accumulation in the innermost part of molecular accretion flows surrounding the nearest supermassive black hole, which will be used to infer the formation mechanism of the AGN obscuring dust tori. | Galaxy chemistry, Galactic centres/nuclei | Galaxy evolution | 2018-01-20T19:09:16.000 |
| 4435 | 2011.0.00008.E | 0 | Orion KL Bands 3 and 6 | ALMA engineering data release. | 2018-07-10T12:50:54.000 | ||
| 4436 | 2016.1.01203.S | 33 | Is the Centrifugal Barrier Associated to Outflow Mechanisms? The L1527 Case | In star formation, angular momentum of the gas plays important roles both in formation of a rotationally-supported disk around a protostar and in launching outflows. Although these two phenomena are expected to be related to each other, few observational studies have been reported on their relation. In this program, we are going to observe the disk/envelope system and the outflow toward the low-mass Class 0 protostar IRAS 04368+2557 in L1527 at a high spatial resolution, and examine their mutual association in detail. In particular, we focus on the centrifugal barrier of the infalling-rotating envelope, which we recently discovered in this source with ALMA, as a possible launching point of the outflow. Extensive analyses of our ALMA Cycle 0 and 2 data indeed indicate a hint that the gas of the disk/envelope system suddenly loses its angular momentum at the radius of the centrifugal barrier. These observations will provide us with rich and new insight into the detailed physical processes of disk formation as well as mechanisms of the outflow, which are both outstanding problems in astrophysics. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2018-02-13T17:01:54.000 |
| 4437 | 2023.1.00999.S | 0 | First ALMA imaging of dusty carbon-rich Wolf-Rayet binaries | Dust is of central importance to the cosmic cycle of matter. Carbon-rich Wolf-Rayet stars (WC) can be prolific factories of dust, however whether they are major contributors to the galactic dust budget depends on the survivability of the dust, which remains to be investigated. Equally pressingly, much of the mechanism by which dust forms is unknown. Recent JWST images of the colliding-wind binary WR140 reveal a striking series of 20 concentric dust shells, demonstrating that dust in this system may survive deep into the ISM. To understand whether long dust survival timescales around such systems are common, we propose to image two WC binaries that are known to be potent dust producers. Infrared observations have already revealed these systems to host hot, close-in dust. The proposed observations will leverage the capabilities of ALMA to image distant, cool dust to test dust survival, track its temperature evolution, allow for geometric modelling to study dust formation conditions and map any CO, which has been tentatively detected in WR112 by the SMA. Taken together, these observations will help us understand the role of dusty WC stars in enriching the cosmic dust content. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2025-11-14T09:01:27.000 |
| 4438 | 2016.1.00027.S | 18 | CO vs. CI in Henize 2-10 | We propose a comparative study of CO and CI emission in Henize 2-10, the first dwarf galaxy discovered with a supermassive black hole. Atomic carbon, CI, is an alternative tracer to CO of molecular gas that has received increasing attention in recent years. The ground-state fine-structure line CI at 492 GHz has shown to be a good tracer of molecular gas in Galactic giant molecular clouds (GMCs), where a linear correlation has been found between CI and CO isotopologues. CI and CO have also been found to coexist in external galaxies (e.g., Gerin & Phillips 2000). Yet due to the poor transparency of the Earth's atmosphere at 492 GHz, studies of CI in external galaxies are rare. But with ALMA's remarkable sensitivity, we can conduct extragalactic CI observations in a reasonable amount of time. We propose to observe the starburst dwarf galaxy He 2-10 in both CI and CO, with the objective of doing a detailed comparison of the molecular tracers and the GMC properties. We expect to identify at least ~20 CO and CI GMCs; this would be the largest systematic study, to date, which compares CO and CI in the same dwarf galaxy on a systematic basis. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-07-28T13:10:59.000 |
| 4439 | 2023.1.00014.S | 0 | Microphysics and astrophysics at play in an assembling massive galaxy at cosmic dawn | Understanding how the first massive black holes and galaxies grew <1 Gyr after the Big Bang is an open question of modern astronomy. The quasar PJ308-21 at z=6.2342 is the poster child of such rapid growth. The central ~1e9 Msun black hole is accreting at its Eddington limit, embedded in a galaxy with a gaseous reservoir of ~1e11 Msun that forms ~200 new stars every year. A companion galaxy is tidally stripped by, and on the verge to merge with the host galaxy of the quasar. This exceptional laboratory of galaxy evolution has been targeted with HST, Chandra, ALMA, VLT, and very recently JWST. We propose to complete this rich dataset with a sensitive search for [OIII] 88um, [NII] 122um and [NII] 205um. These three lines, together with the [CII] 158um map in hand, and the JWST data, will unveil a suite of properties of the ionized ISM: electron density, temperature, pressure, metallicity, hardness and origin of the photoionizing flux, etc. Such a wealth of information on the microphysics of the gas is new for the distant Universe, and will open a new window on our understanding of the astrophysics of galaxy assembly and growth at cosmic dawn. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-09-17T10:46:12.000 |
| 4440 | 2022.1.01558.S | 0 | Origins of Accretion Outburst: Searching for Gravitationally Unstable Disk in HOPS 383 | Recent studies have shown that episodic accretion plays a vital role in mass accretion in low-mass star formation. These bursts thought to be caused by gravitational instability in disks, dramatically increase the luminosity of protostars and can have a significant effect on the chemistry of the systems. HOPS 383 is the youngest known outbursting protostar with a luminosity increase of 35x around the year 2006. We propose to observe HOPS 383 to search for signatures of gravitational instability such as spiral arms with 0.025" resolution (10 au). Previous models (Dong et al. 2016) and observations (Liu et al. 2016) show that clumps and spiral arms should be visible with high-resolution (<0.1") observations. We aim to detect these signatures of gravitational instability in the observed continuum. We will also observe molecular lines to constrain the properties of the system, allowing us to accurately determine the stellar mass and look for possible signatures of previous outbursts. Additionally, we plan to observe complex organic molecules such as H2CO and CH3OH resulting from evaporated ices during the outburst that were previously undetected in lower resolution observations. | Disks around low-mass stars | Disks and planet formation | 2024-11-21T09:37:02.000 |
| 4441 | 2015.1.01578.S | 15 | Resolving water emission in the early universe | We propose to detect and image water lines and infrared luminosity in three lensed starforming galaxies at z~3 from the SPT survey. With the lensing, we will achieve 1 kpc spatial resolution in the source plane. This will be the first time water is spatially resolved in galaxies at high redshift. We will test the recently observed and remarkable linearity of the L_H2O/L_IR correlation. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-08-26T19:36:05.000 |
| 4442 | 2015.1.01518.S | 47 | The star formation law and its drivers in a maximal Eddington-limited starburst at z=3 at <40 pc resolution. | ALMA's long baselines now offer a superb chance to probe intense star formation in high-z galaxies on very fine scales of few 10s of pc, if gas and dust surface brightnesses permit. Here we propose to probe the star-formation law and underlying physical mechanisms in the brightest high-z galaxy on the sub-mm sky seen with Planck, a 1.5" diameter Einstein ring with a FIR SED peaking at 1 Jy, and bright CO lines up to at least 11-10. G244.8+54.9 at z=3.0 is a maximal starburst forming ~17900 Ms yr-1 kpc-2, near the Eddington limit, and about 10x more vigorously than the recently observed lensed galaxy SDP.81. We will (1) Characterize gas and star-forming clumps at 30-40 pc resolution (akin to sizes of individual giant molecular clouds!) (2) Search for the peak of the CO ladder and perhaps variations in CO ratios. (3) Probe the kinematics and morphology of the dense gas tracers HCO+, HCN, HNC, and 13CO. Do they really trace a separate component or are they mixed with the CO, perhaps in a turbulent multi-phase environment? (4) Search for feedback and wind signatures, including OH119 in absorption, to break the degeneracy between infall, rotation, turbulence and gas outflow. | Starbursts, star formation, Outflows, jets, feedback | Active galaxies | 2017-05-15T14:45:47.000 |
| 4443 | 2021.1.00547.S | 21 | Wide ASPECS: Advancing Molecular Deep Fields to Large Areas | Molecular deep fields have proven to be a fundamental tool to constrain the cosmic density of molecular gas, the natural counterpart of the cosmic star formation rate density. By scanning blindly for molecular gas emission from CO, they probe the fuel for star formation in galaxies without any preselection of sources on their multi-wavelength properties. While molecular deep fields, culminating in the ALMA Spectroscopic Survey Large Program, are now obtaining sufficient in depth to constrain the knee of the CO luminosity function (LF), they have so far been lacking in area to constrain the bright end. We propose to extend the deep field approach to an unprecedentedly large area in Band 3 (52.5 arcmin2, ~7x the area of the ASPECS Large Program). These observations were started in an earlier Cycle and we here propose to complete the remaining 13.3h of the project. This dataset will pin down the bright-end of the CO LFs at high redshift, and put the galaxies preselected based on ancillary data into the broader context of the underlying population of molecular gas emitters. Additionally, we will place the first direct constraints on the large-scale clustering of CO-bright galaxies. | Galaxy structure & evolution | Galaxy evolution | 2023-04-15T00:00:00.000 |
| 4444 | 2021.1.00686.S | 5 | Bipolar Outflows near Sgr A* | Using ALMA, a population of 13CO (2-1) sources were discovered within the inner 2pc of Sgr A* resembling protostellar outflows seen in star forming regions. These sources show approaching and receding lobes of dense gas created during the formation of low-mass stars. The inferred properties, linewidth, jet length, outflow force and total mass of all eleven bipolar sources are consistent with those of young stellar object (YSO) bipolar jets in the disk of the Galaxy. This proposal requests a study of these tantalizing results by making high spectral and spatial resolution observations to detect SiO (5-4) emission entrained by the jet. Detection of SiO emission with velocities of 10's of km/s associated with 11 CO lobes, will provide proof of protostellar jets. The secondary motivation is to observe other molecular diagnostics such as 13CS(5-4) and 13CO(2-1) and 218-235 GHz dust continuum from protostellar disks. A census of the population of low-mass stars would provide a strong constraint on the IMF near Sgr A* and a better estimate of the recent star formation rate with implications on the stellar mass budget in the central pc of the Galactic center. | Intermediate-mass star formation | ISM and star formation | 2023-04-14T20:46:53.000 |
| 4445 | 2018.1.01014.S | 5 | Two's company: Pairs of Keplerian discs at the heart of two massive protoclusters | A fundamental unanswered question in star formation is how, precisely, high-mass stars (M> 8 Msun) acquire their mass. We have recently discovered two remarkable systems, each containing two candidate Keplerian high-mass protostellar disks separated by < 6000 AU. The existence of such closely clustered disks, if confirmed, represents an important new constraint for models of massive star formation: the requirement to produce multiple high-mass (proto)stars with disks within <0.05pc. More remarkably, in one system the disks appear to be misaligned by 180 degrees, posing a challenge to the canonical picture of disk formation as a consequence of the orderly collapse of a rotating core. We propose to image these systems at 0.08" (100 AU) resolution in multiple CH3CN and isotopic CH3CN ladders (J=12-11, J=13-12, and vibrationally excited CH3CN) to resolve the extent and kinematics of the candidate disks and so directly measure the masses of their central protostars. By directly measuring protostellar masses and disk masses and sizes in these highly clustered environments, we will provide new quantitative benchmarks for massive star formation models. | High-mass star formation | ISM and star formation | 2022-08-23T18:08:58.000 |
| 4446 | 2015.1.01363.S | 33 | Large scale infall or local collapse forms massive clusters? | The origin of the distribution of stellar masses, in particular of massive stars, is one of the most fundamental open questions of modern astrophysics. Whether they form by a high-level of supersonic micro-turbulence, converging flows or large-scale global collapse is still not settled. We therefore aim here at an unprecedentedly complete view on the kinematics of star forming gas towards the recently discovered most pristine massive clump known to date, G23.21-0.38, based on the ATLASGAL 870 micron survey and its spectroscopic follow-ups. Using high density cold gas tracers (HNC, HCO+, HN13C) we want to look for signatures of global collapse initiated on large scale (>35''), converging flows, and compare the kinematics with the location of dense cores on small scales (2''). The targeted source is entirely dominated by cold gas on a 6 pc scale, and we have strong evidence for a deeply embedded high-mass protostar exhibiting class II methanol maser emission, broad outflow wings, and a particularly high mass infall rate towards its center. We aim to reveal whether local or global collapse sets in first for forming rich clusters. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-05-03T17:16:57.000 |
| 4447 | 2021.2.00064.S | 63 | First direct measurements of dust temperature in quasars at cosmic dawn | Among the >60 quasar host galaxies detected in [CII] and underlying dust continuum to date above z=6, when the universe was <1 Gyr old, only a handful have a published measurement of their dust emission in temperature-sensitive bands (at rest wavelengths <150 um). In order to infer key quantities in the characterization of these early massive galaxies, such as IR luminosities and associated star formation rates, we wildly extrapolate from the temperature-insensitive Rayleigh-Jeans part of the dust emission, or we need to assume templates. Here we propose to alleviate these restrictions by sampling the observed 400 GHz (~100 um rest-frame) dust continuum in quasars at z>6 using the ACA. We target all of the 12 quasars known at these redshifts that 1) have been already detected at 158um (rest-frame) with F_nu>1.5 mJy; 2) have not been observed in band 8 with ALMA; 3) are visible from ALMA. Each observation can be carried out within a few hours. As the quasars are spread over the sky, this program is an excellent filler for the ACA, and does not require the sensitivity nor the angular resolution of the main array. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-09-20T16:00:12.000 |
| 4448 | 2018.1.01710.S | 24 | Resolving into clumps scales in a redshift 3.6 hyper-luminous major merger | The redshift 3.6 strongly lensed submillimeter galaxy (SMG) G09v1.97 is one of the most luminous galaxies known in the early universe. Amplified by a factor ~10, its intrinsic infrared luminosity is exceeding 10^13 Lsun. Recent 0.3" ALMA observations reveal the source plane morphology in the dust and the kinematics of the molecular gas, at spatial scales of ~700pc, indicating that it is a very luminous major merger in its final phase. Such a "high-redshift Arp220", being somewhat much more luminous, offers us important insight into the extreme star formation conditions. Therefore, we propose a further zoom-in 0.05"-0.1" ALMA observation in various tracers of gas and dust continuum, resolving the source into the clump scales (~100pc). The proposed observation of the emission lines covers all the phases of the gas from ionized, neutral to the molecular phase (via C+/C/CO), and connects both properties of gas and dust (with two transitions of H2O lines and dust continuum). The resulting high-quality images will provide a unique view of a merging system in the early universe based on the set of tracers that are mostly inaccessible at such a spatial-resolutions in local mergers. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2020-11-19T18:01:53.000 |
| 4449 | 2023.1.01629.S | 24 | Do massive stars form differently in the Magellanic Cloud? | Massive stars play important roles in cosmic history, but the formation of massive stars is still poorly understood, particularly in the low-metallicity regime. Here we propose to conduct a pilot survey towards three massive YSOs in the Magellanic Clouds with an unprecedented resolution of ~1500 au, enabling a comprehensive characterization of the physical properties of the circumstellar disks and inner envelopes associated with these YSOs. We will search for evidence of disk rotation at a few 1000 au scale and characterize the thermal/dynamical properties of disk/inner envelope. The results will be compared to simulation and Galactic studies to examine the metallicity dependence of massive star formation. This survey will also serve as a benchmark for future observations with larger sample size and higher spatial resolution. | High-mass star formation, Magellanic Clouds | ISM and star formation | 2024-10-25T13:47:22.000 |
| 4450 | 2021.1.00776.S | 32 | CAP - Cold Accretion in Perseus | Bright Cluster Galaxies (BCGs) are giant elliptical lying at the center of galaxy clusters. They are the best examples of AGN-feedback at play: (i) large cavities have been dug into the intra-cluster medium (ICM) by the radio-jet (ii) the energy released by the AGN is a powerful agent to regulate the overcooling of the hot ICM onto the central galaxy (iii) they are surrounded by a huge network of molecular filaments that appear to be an important feature of the feedback loop. A key question at the heart of our understanding of galaxy evolution is how efficiently the energy released by the AGN couples to the ICM. To shed light on this question, we propose to observe at 70pc-resolution a 8.7kpc-region inside one filament of NGC1275 (Perseus cluster). This emblematic source is unique for (i) its proximity which makes it possible to reach very small scales and (ii) the ancillary data available in the filaments at all possible wavelengths. Combining ALMA and ACA we propose a multi-scale study of the morphology and dynamics of the internal structure of the thread-like filaments to probe their origin and their role in the AGN-feedback mechanism. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2023-09-23T20:09:51.000 |
| 4451 | 2021.2.00036.S | 20 | Water BEARS | We propose a comprehensive study of water lines in the brightest sub-millimetre galaxies (SMGs) on the Southern sky, from our compilation of ALMA redshift campaigns on Herschel galaxies in cycles 4-7 (collectively termed the Bright Extragalactic ALMA Redshift Survey, or BEARS), more than tripling the number of H2O detections in SMGs, in order to measure star formation rates (SFRs) and test for drivers of "starburst" mode vs "main sequence" stellar mass assembly in the ramp-up to Cosmic Noon. Water is the most abundant molecule in star-forming galaxies after H2 and CO, and is an important coolant of warm gas with line luminosities comparable to CO. The H2O transitions are driven by pumping from far-IR photons, so the H2O line luminosities correlate linearly with far-IR luminosity and are hence the best tracer of SFR over at least three orders of magnitude. The H2O and CO line profiles are very similar, and resolved CO and H2O studies show they are co-spatial, implying that gravitational lens magnifications derived from CO morphologies can be applied also to H2O lines, and that differential magnification between H2O and CO can be neglected. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2023-09-12T09:36:20.000 |
| 4452 | 2021.1.00279.S | 36 | Probing Black Hole Mass in Seyfert AGN Using Atomic-Carbon Gas | Accurately weighing supermassive black hole mass (SMBH, Mbh) using ALMA high-spatial-resolution observations of circumnuclear gas discs (e.g. low-J CO) at scales from a fraction to a few times of the black holes sphere of influence radius (Rsoi) has been applied for a wide range of galaxy morphologies from early-type (ETGs) to late-type (LTGs). However, its application for Seyfert active galactic nuclei (AGN) was limited to a few ETGs; and has not been explored extensively in LTGs due to the inegligible distributions of low-J-CO outflows or central holes driven by AGN. Recent work in the Seyfert type-1 NGC 7469 revealed the atomic-[CI](1-0) gas excited from the X-ray-dominated region being a better probe of Mbh than CO in AGN because of the dramatic increase in atomic carbon abundance by dissociating CO molecules. To solidify this new Mbh tracer in AGN, it is necessary to test it further on other AGN with higher spatial resolutions. Here, we propose ALMA high-spatial-resolution observations for a sample of 9 local AGN to characterize their atomic-[CI](1-0)-gas contents and kinematics at the spatial scales of a fraction or several times of the SMBHs' Rsoi. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-09-23T14:34:14.000 |
| 4453 | 2023.1.01215.S | 0 | A Search for an Intermediate Mass Black Hole in a Very Low-Mass Galaxy | We propose to use ALMA observations to perform a dynamical mass measurement of a putative black hole in the galaxy ESO274-01. This will be the lowest mass galaxy (3x10^8 Msun) in which a dynamical black hole mass search will be conducted. The proximity of the galaxy (2.8 Mpc) combined with ALMA's unparalelled spatial resolution will enable detection of any black hole above 3x10^4 Msun. There is strong evidence for the presence of nuclear molecular gas in this galaxy, and our observations seek to resolve and measure the kinematics of this gas. The centers of low-mass galaxies are the best places to find Intermediate mass black holes (IMBHs). These IMBHs can play a crucial role in understanding both the origin of black hole seeds, and in constraing the currently unknown extrapolation of black hole scaling relations to lower masses. | Galactic centres/nuclei | Active galaxies | 2025-08-12T11:41:41.000 |
| 4454 | 2015.1.00094.S | 34 | Surveying the Seeds of Star Formation: Starless Cores in Orion B North | Recent interferometric surveys of starless cores have found that 1) 5-20% of these objects actually harbor low-luminosity star-forming objects, and 2) none of the truly starless cores have any detectable substructure or evidence for fragmentation. These surveys, however, were intentionally biased and suffer from small sample sizes. To begin to address this problem, we have conducted ALMA surveys of starless cores in Chamaeleon I (cycle 1) and Ophiuchus (cycle 2). We have detected evidence for both starless core fragmentation and hidden protostars in the Ophiuchus sample, and have used nondetections in the Chamaeleon I sample to constrain the evolutionary stage of the starless core population in this cloud. Here we re-propose to survey starless cores in Orion B North (filler time in Cycle 2, no data yet obtained) in order to complete our survey of starless cores across diverse environments. We will determine definitive classifications (starless or protostellar), discriminate between models of star formation that predict different paths for the origin of binary protostellar systems, and test the extent to which the environment influences the path(s) of star formation. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2018-04-06T20:29:00.000 |
| 4455 | 2024.1.00117.S | 0 | A survey of Zeeman sensitive molecules, in total intensity, towards star forming regions | Magnetic fields are acknowledged for their dynamic role in the interstellar medium (ISM), especially in star forming regions, as shown by the Planck mission. Howevewr, measuring magnetic field strength accurately is complex and demands high sensitivity and precision due to the challenges posed by the Zeeman effect. Our proposed study aims to identify the most intense compact emission spots from molecules sensitive to the Zeeman effect, such as CN and SO. We plan to map CN and SO emissions, along with continuum emission, across all 373 pointings that have been previously mapped with ALMA in full polarization from Cycle 2 onward. Utilizing various structure finding algorithms, we will compile a catalog of compact and intense CN, SO, and continuum sources suitable for future Zeeman effect observations with ALMA. This catalog will facilitate investigations into the scaling relationship between magnetic field strength and density, specifically to address whether the power law index follows a n^1/2 or n^0.65 power law. Additionally, by focusing on regions previously mapped by ALMA in full polarization, we open possibilities for future estimates of total magnetic field strengths. | High-mass star formation, Low-mass star formation | ISM and star formation | 2025-10-16T00:13:30.000 |
| 4456 | 2019.1.01719.S | 7617 | Bulge Asymmetries and Dynamical Evolution (BAaDE) IV | A radio survey of red giant SiO sources in the inner Galaxy and Bulge is not hindered by extinction. Extremely accurate stellar velocities (<1 km/s) are obtained with minimal observing time (<<1 min) per source. Our aim to detect over 20000 SiO maser sources yields data comparable to optical surveys with the additional strength of a much more thorough coverage of the highly obscured inner Galaxy and Plane. Large samples reveal dynamical structures, minority populations and their velocity structure may be compared with kinematics of molecular gas, complex orbits in the bar, or stellar streams resulting from recently infallen systems. Modeling of the bar and bulge dynamics will be done using this new kinematic information in the inner Galaxy. Our survey yields bright SiO masers suitable for follow-up Galactic orbit and parallax determination using VLBI. We observed 19000 sources with the VLA at 43 GHz (-570% detection rate). We propose to use ALMA to incrementally survey 1730 of the remaining ~7600 sources in the Southern Bulge (-110 | Spiral galaxies, Galactic centres/nuclei | Local Universe | 2021-03-31T13:44:20.000 |
| 4457 | 2023.1.00545.S | 0 | Weighing all protostars in Ophiuchus through their disk kinematics | We propose an ALMA program to investigate protostellar masses of a complete sample of 25 Class 0/I protostars in the Ophiuchus star forming region through the direct observations of the surrounding Keplerian disks. The dynamical mass from Keplerian disk motion is the only reliable method for stellar mass determination in the embedded phase. Our homogeneous sample of protostars selected from the Ophiuchus region allows us to directly obtain the protostellar mass function (PMF) for the first time, linking the core mass function and the initial mass function of the field stars. The stellar mass determination allows us to derive the mass accretion rate from the disk to the star, while the disk mass can be estimated from the continuum emission we will observe. Relationships of these two physical quantities and the protostellar mass will be investigated, and will be also compared with those for Class II sources in Ophiuchus. Our homogeneous sample of protostars in Ophiuchus enables us to carry out a statistically study of how disk properties are linked to the central stellar mass and evolve as protostars evolve to the Class II sources without ambiguous regional varieties. | Low-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 4458 | 2024.1.01367.S | 0 | The full census of cold gas in disk galaxies across the past billion years | The balance of neutral and molecular hydrogen, how the components evolve with redshift, and their dependence on galaxy properties, are open questions. The intrinsic faintness of neutral hydrogen (HI) has until recently been the limiting factor in measuring the full cold gas content of galaxies at cosmological redshifts. With the SKA precursor facility MeerKAT, resolved observations of HI at z=0.08, corresponding to one billion years of lookback time, are now possible. We propose to use the ACA to observe the molecular gas via the CO(2-1) emission line in a representative sample of galaxies with resolved HI observations from MeerKAT at 0.0 | Spiral galaxies, Surveys of galaxies | Local Universe | 2025-11-12T11:25:00.000 |
| 4459 | 2023.1.00235.S | 0 | The ALMA-JWST synergy: [OIII]88um and [CII]158um emission line observations of z=9.51 galaxy identified by JWST | The z>9 Universe, corresponding to the first few hundred million years after the Big Bang, witnessed the formation and growth of the first galaxies. Yet, this important epoch remains only little charted, with a handful of sources spectroscopically confirmed and little constraints are obtained on their episodes of first star formation. Observations enabled by the James Webb Space Telescope (JWST) and ALMA provide a unique opportunity to characterize detailed properties of the interstellar medium of high-redshift galaxies. During the JWST Cycle-1, a gravitationally magnified star-forming galaxy, RXJ2129-z951, was identified at z=9.51. This galaxy is currently the only example that ALMA can simultaneously observe multiple emission lines as other galaxies are too faint and/or affected by atmospheric absorption. Here, we propose to exploit this unique opportunity to provide FIR perspective by observing [CII] 158um and [OIII] 88um emission lines (i) to constrain warm to cold neutral gas properties, (ii) to explore the faint end of [OIII]/[CII] ratio, and (iii) to search dust emission. The proposed observation will pave the way for the future large ALMA follow-ups of JWST galaxies at z>9. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2025-07-23T21:13:58.000 |
| 4460 | 2023.1.00318.S | 0 | How important are magnetic fields in early disk galaxies? | Cold galactic disks have been found in dusty star-forming galaxies at z~4, challenging existing paradigms of galaxy formation. Magnetic fields play an active role during their formation, but are ignored in most analyses. In the nearby Universe, strong (~10uG) and ordered magnetic fields have been widely reported in disk galaxies, but we have essentially zero knowledge about magnetic fields in galaxies beyond z~2. This proposal seeks to bridge the gap between galactic kinematics and galaxy-scale magnetic fields in the early Universe, providing a new opportunity to understand disk formation in the early Universe. With the proposed observations, we will 1) quantify the importance of magnetic fields for the cold disk formation based on high-resolution observations of magnetic fields and kinematics; 2) discriminate between amplification mechanisms and constrain timescales for the development of large-scale ordered magnetic fields in early galaxies; 3) explore the role of magnetic fields in modulating gas inflows and outflows in the distant starbursts. | Spiral galaxies, Outflows, jets, feedback | Local Universe | 3000-01-01T00:00:00.000 |
| 4461 | 2023.1.00536.S | 0 | The ACA ORdinary Cloud Study of the Large Magellanic Cloud | We proposed to observe 100 molecular clouds in the Large Magellanic Cloud (LMC) at high resolution to test whether there is evidence for a "single-cloud" star formation law. Specifically, we are testing where there is an empirical relationship between the column density of molecular gas and the local star formation rate within clouds, which has been found in Milky Way studies but the opposite result is found in extragalactic studies. Using direct YSO counts from infrared observations, we will set local star formation rates. Then, using resolving small star forming sturctures in each cloud we will measure the local column density, free-fall time, and the degree of gravitational binding to determine if these physical parameters drive star formation. This will be the largest homogenous survey of highly resolved molecular clouds where we have direct measures of the local star formation rate. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2025-01-02T13:40:23.000 |
| 4462 | 2024.1.01335.S | 0 | Molecular cloud observation around the SS433 eastern X-ray jet | Microquasar jets are focused on as powerful cosmic-ray particle accelerators in our galaxy. Since they can be resolved the detailed structure, they provide us with plenty of knowledge of the cosmic-ray particle acceleration mechanism not only for microquasar jets but also for AGN jets, which are believed to be the scaled-up sources of microquasar and candidate accelerators of extremely high energy cosmic-ray particles above 10$^{18}$ eV. Microquasar SS433 is the most suitable target for investigating cosmic-ray particle acceleration since the leptonic TeV gamma-ray emission was identified at the SS433 X-ray jet with the H.E.S.S. observation. We discovered the molecular clouds at the base of the SS433 X-ray jet, where the notable cosmic-ray particle acceleration happens. If the interaction between these clouds and the SS433 X-ray jet is certain, we get evidence that the shock-cloud interaction activates the cosmic-ray particle acceleration. With this ALMA proposal, we aim to verify the interaction between the molecular clouds and the SS433 X-ray jet by discovering the signatures of shocked clouds through 19.44 hrs observation of 12CO(J=2-1), 13CO(J=2-1), and 12CO(3-2). | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-10-07T16:20:22.000 |
| 4463 | 2015.1.01017.S | 18 | Direct Imaging of Vertical Structure in an Edge-on Protoplanetary Disk | Protoplanetary disks are proposed to be characterized by radial and vertical gradients in density, temperature, ionization, radiation flux and chemistry. Spatially resolved ALMA observations of molecular lines have confirmed the presence of radial temperature and chemical structures in disks, while constraints on the vertical structures remain scarce. We propose to exploit the exceptional spatial resolution of ALMA and the viewing geometry of the edge-on disk AA Tau to obtain the first direct imaging constraints on the vertical chemical and ionization structure in a protoplanetary disk. We will target molecules and ions proposed to trace the disk atmosphere, warm molecular layer and cold midplane to benchmark our understanding of how disk structures and chemistry depend on disk height. | Disks around low-mass stars | Disks and planet formation | 2017-09-29T21:59:06.000 |
| 4464 | 2015.1.01309.S | 26 | ALMA as a sensitive IMF probe in galaxies: opening a new frontier | The stellar Initial Mass Function (IMF) plays a fundamental role in all galaxy formation, star formation and cosmological models. ALMA can powerfully probe the IMF types within heavily dust enshrouded star-forming galaxies, by measuring isotopic ratios of C and O (12C/13C, 16O/18O), which can be derived using the corresponding isotopologues. Here we propose to use ALMA to observe the ladders of isotopic CO lines (12CO, 13CO, and C18O) in four bright strongly lensed submm galaxies at redshifts ~2, at the peak of star formation in the Universe.. With non-LTE/Bayesian radiative transfer analysis and state-of-the-art galactic chemical evolution models (considering time-delay effects of the yields), the applied unique data and methods will serve as critical clues for the IMF variation across the cosmic time. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-06-30T12:39:41.000 |
| 4465 | 2019.1.00779.S | 347 | SPT z=4-7 protoclusters: cluster membership and dynamics from line observations | From the SPT 2500deg^2 survey, we have uncovered a complete sample of 9 massive protoclusters at z=4-7, appearing as the most luminous, unlensed structures in the survey volume. The protoclusters have spatially extended LABOCA contours, resolve into multiple sources with initial ALMA followup, show no lensing galaxy in deep optical/IR imaging, and exhibit large overdensities of LABOCA sources in the surrounding field. The proposal leverages our extensive results to date on SPT2349-56, which clearly appears to represent an actively and rapidly forming cluster core. This proposal is part of a coordinated effort to collect the required observations to prove that our complete SPT-PC candidate sample indeed traces the formation of the most massive structures in the Universe, and to provide the necessary observations for the full exploration of our survey. Here we focus on the 5 PC candidates for which we have ALMA redshifts. We propose to ALMA for deeper / wider followup to study their natures as distant, massive protoclusters. Our survey will provide an important baseline for models of the earliest massive galaxy cluster formation. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-02-19T17:01:43.000 |
| 4466 | 2016.2.00147.S | 212 | How does CO trace the HI-to-H2 Transition at Low Metallicity? | A key remaining question in star formation and galaxy evolution is how the atomic gas transitions to molecular, and in particular, the effect of metallicity on this process. We propose to look for faint CO emission using the ACA in standalone mode towards a sample of 20 sources spread across the Magellanic Clouds that have HI absortion observations as part of an ongoing large ATCA project lead by Co-I McClure-Griffiths. We will be able to compare the CO intensity to the HI spin temperature and fraction of cold neutral gas to constrain how metallicity affects the transition from molecular to atomic gas. By revealing how much CO emission exists along these lines of sight and comparing to the optical depth of HI determined from the absorption line measurements, we will constrain how much optically thick HI gas contributes to the "CO-dark" or "CO-faint" gas component at low metallicity. With the proposed ~80 single-pointings towards the background continuum sources with HI absorption measurements, we are in a unique position to study how environment affects the CO emission and its connection to the HI-to-H2 transition. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2018-10-09T07:31:37.000 |
| 4467 | 2015.1.01254.S | 31 | Unification of Gamma-Ray Burst: Host Galaxy of the First Off-Axis X-ray Flash 020903 | We aim to complete the unification of Gamma-Ray Burst (GRBs) and X-ray Flashes (XRFs) by confirming the burst site properties. Observing the GRB properties require an ultra-relativistic collimation and a jet structure. Off-axis jet events occur as a natural consequence of GRB jet production and XRF could be same origin. The expected properties of off-axis jet events include the following: (1) absence of prompt emissions in the high-energy band, (2) the afterglows are characterized by 3-component light curves with rising, peaking, and rapidly decaying phases, (3) they have the same optical color as on-axis afterglows, and (4) association with a host galaxy, whose properties are similar to those of on-axis GRBs. On the basis of our afterglow and prompt radiation analysis by using the most favorable XRF sample, we demonstrated that the off-axis model with a large viewing angle satisfyingly describes the observed properties. In this analysis, we already confirmed 3 of 4 unification properties, except their host galaxy properties. Hence, a final effort to confirm similar burst environmnets and to observe the host galaxy is crusial for establishing the unification between GRBs and XRFs. | Starbursts, star formation | Active galaxies | 2018-04-04T04:40:02.000 |
| 4468 | 2016.1.00652.S | 43 | Unveiling the enigmatic AGB star GX Mon | The evolution of Asymptotic Giant Branch (AGB) stars is characterised by mass loss, however the details of the interplay between the different mechanisms involved and the role of binarity in shaping the resulting planetary nebula remain unclear. The necessary constraints can be derived from maps of the morphology and velocity distribution of the gaseous circumstellar envelope, which ALMA has proved to be the ideal instrument for. We propose to use CO and other tracers to map the morphology and velocity distribution of the circumstellar envelope around GX Mon, a rather intriguing oxygen-rich Mira variable. Recent VLBI observations of SiO masers in the extended atmosphere of the star show a velocity gradient indicative of rotation, which may be related to an unseen binary companion that could be inferred from our observations. Additionally, HST data reveal a structure at around 3500 AU from the star that is tantalisingly reminiscent of a detached shell. If confirmed, this would make GX Mon the first oxygen-rich AGB star to be associated with a history of thermal pulses. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-03-01T18:07:09.000 |
| 4469 | 2013.1.01305.S | 2 | Witnessing the Origin of the Interstellar Turbulence: Rapidly moving Small Scale Structures in Multi-Phase Interstellar Medium | We propose ALMA observations to detect small scale (~ a few 100 AU) cloud structures at the periphery of a molecular cloud as the origin of ubiquitously observed super-sonic turbulence driven by thermal instability. Such small scale structures are predicted by theoretical studies, and we aim to observe a direct evidence of the two-phase medium model. The preceding observations with the 45m telescope at the edge of a nearby molecular cloud have discovered small scale (a few 1000 AU) structures in 12CO (1-0) with the line width of ~ 0.6 km/s, which is significantly smaller than the typical value of 12CO in molecular cloud. It suggests that molecular cloud is composed of small-scale dense and cold structures and their overlapping effect makes it appear to be a turbulent entity as a whole. The theoretical model suggests that the cloudlets grow by coalescence of even smaller structures. It is very likely that fainter and smaller CO clouds exist but not resolved by the 45m beam. The aim of this project is to detect many small scale structures down to a few 100 AU, which will be the observational evidence supporting the theoretical two-phase turbulence model. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-07-20T16:18:18.000 |
| 4470 | 2017.1.00877.S | 22 | N79: The Once and Future 30 Doradus | We have discovered the existence of a massive and extended star forming complex in the unexplored southwest region of the Large Magellanic Cloud (LMC). Previously known as N79, this region harbors the highest density of massive Young Stellar Objects (YSOs) in the LMC, only to be challenged by 30 Doradus. Moreover, at the heart of this cluster lies a massive YSO with a lower limit on luminosity of 1.5x10^6 L_sun, closely matching the luminosity of the central ionizing cluster of 30 Doradus, R136 (1.0×10^7 L_sun; Anderson et al. 2009). Thus, we have found the once and future 30 Doradus. This region coincides with the tip of the northern sprial arm of the LMC (D'Onghia & Fox 2016). Previous ALMA (Cycle 2) observations of this region was of a small 1' x 1' region centered on the most luminous YSO. This proposal focuses on a larger region and will capture the three main giant molecular clouds (GMCs) observed in N79, which harbor a large fraction of young massive stars in the region. We propose to observe 13CO, C18O, CS, and H40 to determine the column density, probe the dense gas, and calculate the hardness of the radiation from the star formation activity in the N79 region. | High-mass star formation, HII regions | ISM and star formation | 2020-01-27T00:00:00.000 |
| 4471 | 2023.1.00812.S | 0 | Comprehensive Study of Molecular Gas in Tidal Dwarf Galaxies | One of the biggest challenges in modern astrophysics is to understand how gas is transformed into stars and how this is influenced by local and global environment. Tidal dwarf galaxies (TDG) form in the debris of galaxy mergers, have higher metallicity than typical dwarfs (inherited from their parent galaxies), and are largely devoid of dark matter. Despite their interest as an extreme dynamical environment, only two published studies have resolved molecular gas in TDGs below kpc scales, and only one of them resolved giant molecular clouds (GMC). In this context, we aim to 1) determine how different and extreme environments affect the ability of molecular gas to form stars, ad 2) analyse the influence of molecular gas organization, particularly the diffuse gas, on the Kennicutt-Schmidt relation. We propose CO(1-0) observations with 12m + ACA + TP in a sample of 6 TDGs, ensuring sensitivity across all spatial scales, from 100-300 pc down to largest angular scales of 70''. This pioneering study will allow us to characterize the gas organization in a statistically significant sample of TDGs, laying the foundation for testing star formation theories across cosmic environment. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-08-23T15:39:08.000 |
| 4472 | 2016.1.01371.S | 17 | Gargantuan or Lensed? Resolving a HyLIRG at z~3 | We propose high resolution (0.1"~0.8 kpc) mapping of a compact HyLIRG at z~3, tracing the [CII] 158um far-IR line and continuum to resolve the dynamics of the source and constrain any gravitational lensing effects boosing its luminosity. This galaxy is one of the brightest sub-mm sources in the sky with L(IR)=1.2x10E14 L(Solar) which is assumed to be due to strong lensing. However, there is no detection of a foreground lens and the source is only marginally resolved with ~0.7" SMA imaging at 870um. Our proposed observations would help create a resolved map of the active star formation traced by the [CII] far-IR line emission, distinguish the energy source powering its luminosity and most importantly, unravel lensed images (if any). The unmatched sensitivity of ALMA could potentially discover in-[out]flows to support-[caused by] the large star formation surface density. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-07-19T21:13:58.000 |
| 4473 | 2018.1.01336.S | 51 | Investigating the multi-mode hierarchical fragmentation of a star forming filament in the Orion B molecular cloud | There is a growing evidence of the key role of dense self-gravitating filaments in the star formation process. Important questions are to understand the physical processes 1) leading to the fragmentation of these filaments into bound cores and 2) governing the properties of these cores (e.g., spacing/clustering, mass, size). To make progress in our understanding of the star formation process, an ideal target is OriBupfil, a star forming filament in the Orion B cloud. Dense cores spaced by 0.1pc are observed along the 1pc-long, high line mass (90Msun/pc) filament. Our IRAM 30m data at 36" (0.07pc) resolution of the N2H+ line show a single-velocity-component ordered sinusoidal patern along the filament. While the 0.3pc period of this structure is larger than the 0.1pc core spacing, it matches a 0.3pc period column density fluctuation. These results suggest multi-scale gas motion, and hence, a possible hierarchical fragmentation process in OriBupfil. The goal of our ALMA proposal is to resolve the small scale (<<0.1pc) velocity structure as traced by N2H+ and HNC to investigate the presence of multi-mode perturbations and study the fragmentation and radial collapse of the filament. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-06-20T00:00:00.000 |
| 4474 | 2023.A.00026.T | 9 | Follow-up observations of SN 2024ggi with ALMA | SN 2024ggi is a newly discovered type II supernova in a nearby galaxy (NGC 3621, ~7 Mpc), making SN 2024ggi a marvelous target to trigger the follow-up observations, especially in the submillimeter band using ALMA. Another reason this target is interesting is that SN 2024ggi has significant CSM interaction during its flash ionization phase. Theoretically, the interaction between the ejecta and a dense CSM can generate radio radiation with a rising time of a few days for higher frequencies (e.g., 200 to 400 GHz). We propose to observe this target using the ALMA to detect non-thermal radiation from ejecta-CSM interaction soon after the explosion. The synergic observations of the ALMA, optical telescopes, and the X-ray telescope will contribute valuable multi-band data of SN 2024ggi and be essential to reveal its physical origin. | Supernovae (SN) ejecta | Stars and stellar evolution | 2024-11-03T20:40:17.000 |
| 4475 | 2017.A.00043.T | 311 | Time evolution of CO & H2O in the Martian atmosphere during a large-scale dust storm | We propose to use the ACA to monitor the evolution of CO and H2O in the Martian atmosphere, on a timescale of weeks and on a global size scale, during the current dust storm. The CO profile will be used to derive the global wind structure and vertical atmospheric temperature profile. The submm H2O line will be observed for the first time; its' profile will give the vertical H2O abundance and the ACA spatial resolution will enable us to derive the H2O distribution over the planet. As well, we can can measure the H2O/HDO ratio, which is predicted to be affected by the exact origin of gaseous H2O. Dust storms are expected to affect the abundances of both of these molecules, as well as their vertical temperature profiles. We can test these predictions with the new observations, giving a better understanding of the Mars weather during and after such global events. The data can be compared with the latest Mars atmosphere models, as well as in-situ measurements by the orbiters and landers currently on the surface. | Solar system - Planetary atmospheres | Solar system | 2018-10-16T00:00:00.000 |
| 4476 | 2019.1.00232.S | 10 | Capturing a planetary nebula eclosion | IRAS 15103-5754 is a water fountain in the very onset of photoionization and therefore in the beginning of the planetary nebula (PN) phase. It exhibits special features that makes it the youngest PN known: a) It is the first PN that shows water maser components tracing a high-velocity jet. b) Its maser components presented a Hubble-like flow, indicating an explosive event. c) It is the first PN showing synchrotron emission. d) This non-thermal emission is being progressively suppressed by the growth of the photoionized region. ALMA cycle 3 observations showed continuum emission from two unresolved sources and line emission (C18O,CO,HCO+) imaged an expanding torus around the brighest one. The spectral index around this brighter source is <2 (with a minimum of 0.6), which is not compatible with dust, but with free-free emission from a photoionized nebula. We aim at resolving this putative photoionized region, to confirm its nature. If so, we would have a unique oportunity to map and monitor the advance of a photoionization front at the birth of a PN. Given the fast evolution of the source, the characteristics we can now observe in this source may not be present in the near future. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2022-09-27T15:35:52.000 |
| 4477 | 2016.1.00949.S | 222 | Uncovering the Early Formation of Extremely Massive Stars | The huge amounts of energy and momentum that very massive stars expel has a significant effect on the physical and chemical evolution of the interstellar medium. Yet despite on-going efforts, their formation remains poorly understood due to the rarity of their progenitors. This proposal aims to advance this understanding by targeting four recently-identified high-mass cores in the Central Molecular Zone. These cores all contain > 100 Msun within radii < 0.1 pc and are young (pre-UCHII), meaning that they are all prime candidates for representing the initial conditions of very high-mass stars. Furthermore, each core displays differing amounts of star-formation activity, potentially providing a unique evolutionary sequence of massive star formation under the same environmental conditions. ALMA's unparalleled sensitivity at high angular resolution will allow us to resolve the structures within these cores down to 1000 AU -- a predicted fragmentation scale for high-mass stars. These data will provide a unique test for star formation theories in such extreme regimes and allow us to place constraints on the dominant physical mechanisms governing the formation of the most massive stars. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-02-27T02:01:04.000 |
| 4478 | 2023.1.01438.S | 0 | The extinction of the rings: constraining beta and grain size distribution from the obscured CO lower emission surface | The dust particle size of protoplanetary disks is a crucial, yet highly uncertain ingredient in our planet formation models. One of the best approaches to constrain this is to measure the spectral index of the dust opacity (beta). We propose an innovative and model-independent method to measure beta using the lower CO emission surface of disks. The lower surface can be extinguished by the dusty midplane. By measuring the extinction of two CO lines, we can directly measure the optical depth at two wavelengths and, thus, beta, avoiding model degeneracies and flux calibration errors. We propose to test this method in the multi-ringed disk of HD 163296 using DSHARP's CO (2-1) data and new 0.1" CO (3-2) observations. Our results will provide unique insights on the particle size distribution of the disk, which can be further constrained when combined with available polarization and multi-wavelength observations. We request a maximum spectral resolution of 26 m/s, which will provide an immense legacy value for disk kinematic studies. Overall, we propose a new method to measure beta that could significantly advance our understanding of the dust content of protoplanetary disks. | Disks around low-mass stars | Disks and planet formation | 2025-07-29T15:51:04.000 |
| 4479 | 2017.1.00888.S | 30 | A puzzling outflow in a QSO a z=2.4 | In Cycle 2 we were awarded ALMA time to obtain CO(3-2) observations of a QSO at z=2.4. The analysis of the ALMA observations have revealed a tentative detection of a CO(3-2) emission line blue-shifted by -2000 km/s with respect to the galaxy systemic velocity and spatially offset by 0.2" (~1.7 kpc) with respect to the QSO. Interestingly, such emission feature is coincident in both velocity and space with the ionised outflow as seen in [OIII]5007. This tentative detection must be confirmed with deeper observations but, if real, it could represent the molecular counterpart of the ionised gas outflow driven by the AGN. We propose deeper CO(3-2) observations to asses the reliability of our detections. In addition, we request CO(4-3) observations to establish the excitation state of the molecular gas in the outflow region | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2019-02-23T15:46:13.000 |
| 4480 | 2018.1.01826.S | 55 | Unveiling the Physics of the Only Known Compact Extragalactic Source of AME Observable by ALMA | For over 20 years, the physical origin and prevalence of Anomalous Microwave Emission (AME) has remained an unsolved problem in astrophysics. Here we propose to use 4.1hr of ALMA time to observe the 90--220 GHz continuum and CO J=2-1 line emission for the only known compact extragalactic AME source observable with ALMA (i.e., NGC4725B) to: (1) Constrain the shape of the AME spectrum. Currently, no data exists at comparable resolution at frequencies >44 GHz, leaving the exact shape of the AME and thermal dust emission completely unconstrained. (2) Measure a robust dust mass and emissivity from the Raleigh-Jeans side of the dust SED. We will test for correlations between the dust mass and AME morphologies that are naively expected if large accumulations of dust are required to produce strong AME. (3) Use the CO line emission to look for molecular gas to both measure the star formation efficiency and gas-to-dust ratio for this young (< 3 Myr) star-forming region. We will additionally use the CO line width investigate whether there is significant turbulence present that could be shattering larger grains, resulting in an accumulation of small grains powering the AME. | Inter-Stellar Medium (ISM)/Molecular clouds, HII regions | ISM and star formation | 2019-10-15T20:45:17.000 |
| 4481 | 2016.1.00948.S | 81 | Searching for the Emergence of Conformity in Nascent Groups | Galaxy groups show "conformity" -- at fixed group mass, satellite colors and morphologies echo the color and morphology of the brightest galaxy or "central". The mechanisms proposed to explain conformity involve differences in hot and cold gas content at fixed group mass, but studies to date have not directly probed how gas physics produces conformity. We propose to search for evolution toward conformity at the stage when groups are first forming and variations in hot and cold gas content are at their most extreme. Our targets are centrals and satellites in three "nascent groups", few-member groups in the mass regime between 10^11.4-10^12 Msun that bridges between solitary gas-dominated dwarfs and mature groups with hot gas halos. Using CO(1-0) maps to obtain separate bulge and disk molecular gas measurements, we will compare galaxy properties such as molecular gas bulge-to-disk ratio and bulge and disk gas depletion times to assess whether and how centrals and their satellites may be actively synchronizing in color and morphology. This pilot study will inform a future program to study the complete set of nascent groups in the volume-limited RESOLVE survey. | Galaxy groups and clusters | Cosmology | 2018-02-22T22:18:04.000 |
| 4482 | 2018.1.00353.S | 14 | Probing B-Fields in the Accretion Streams Feeding VLA1623 Protostellar Disk Through 13CO Polarization Observations | Our proposal aims to understand the role of magnetic fields in the accretion streams connecting the large-scale envelope to small-scale disks. We identify several accretion streams and a Keplerian disk in VLA1623 based on Cycle0 and Cycle 2 13CO (J=2-1) and C18O (J=2-1) data. We request to use Band 6 to measure 13CO(J=2-1) polarization towards accretion streams in VLA1623. The goals of the proposal is to (1) First detection of 13CO polarization (2) Reveal the magnetic field structure from large scale to small scale (3) Test turbulence-enabled disk formation models | Low-mass star formation | ISM and star formation | 2020-10-04T14:31:09.000 |
| 4483 | 2011.0.00863.S | 0 | Tracing the Dust Destruction Zone in Protoplanetary Disks via SiO Rotational Line Emission | Protoplanetary disks are vital objects in star formation. They drive the accretion of matter from the parent cloud material onto the new star whilst dissipating angular momentum away from the system. They are also the sites of planet formation, containing the material, gas and dust, which may form a planetary system encompassing the new star. Disks are active environments and thus are chemically and physically complex. They are heavily irradiated by their parent star and are permeated by shocks as material impinges upon the star and upon the disk itself. Approximately 1 % of the mass of the disk is in dust grains which themselves consist of around 50 % silicate material. Dust grains are destroyed in disks via shock and collisions and grain sublimation can occur in the inner hot regions (T > 1500 K). Dust destruction releases a significant amount of silicon into the gas-phase which is efficiently converted to SiO, hence, SiO is good tracer of the dust destruction zone in protoplanetary disks. We propose to observe SiO rotational line emission in a selection of nearby, warm protoplanetary disks in order to investigate the extent to which shocks and other dust destruction mechanisms influence the gas-phase composition and evolution of the disk. This proposal utilizes the superior sensitivity of ALMA Early Science capabilities to detect SiO in a protoplanetary disk for the first time. | Disks around low-mass stars | Disks and planet formation | 2014-01-17T08:14:24.000 |
| 4484 | 2013.1.00088.S | 2 | The Mass Accretion Reservoir Surrounding a Variably Accreting Young Star | We propose to obtain band 6 continuum observations of the new FU Orionis object HBC722, which was first observed to flare in 2010 and remains in the elevated state to the present day. The flares associated with FUors are generally attributed to enhanced accretion from the surrounding circumstellar disk. Recent SMA and PdBI observations of HBC722 did not detect a circumstellar disk down to an upper limit of 0.02 solar masses, already making it the lowest mass FUor disk known by at least a factor of 3. Our proposed observations will provide approximately 50 times better mass sensitivity than possible with the SMA or PdBI and will probe down to a disk mass of 4.2E-4 solar masses. With these data we will study the physical properties of the HBC722 disk, the evolutionary status of HBC722, and the driving mechanism of the current flare. | Low-mass star formation | ISM and star formation | 2018-06-16T15:54:29.000 |
| 4485 | 2022.1.00998.S | 6 | The Birth of Giants: Assembly of the First Massive Galaxies | Over the last decade, a coherent picture of the Universe during the epoch of reionisation has started to emerge. Optical and near-IR spectra of high-redshift quasars have undoubtedly been the most polyvalent tools in the exploration of the first Gyr of the Universe. To obtain a pan-chromatic legacy sample of the brightest quasars at z~6, ESO recently awarded a Large Programme (XQR-30) to obtain optical/near-infrared spectra of the highest quality in a carefully selected sample. Here we request ~1.5 kpc (0.3") resolution ALMA [CII] imaging of this sample of quasars. These observations are critical for a number of reasons: (a) characterise the host galaxy that cannot be traced in the optical/near-infrared and spatially resolve star formation and gas surface densities; (b) provide accurate systemic redshifts that are crucial to fully exploit the optical spectroscopy; (c) pin-down the frequency of merging events in z>6 quasar hosts. Together with accurate black hole masses from XQR-30, the ALMA data will also put the targeted quasars in the framework of the black hole-host galaxy co-evolution paradigm and shed light on the formation of the first massive galaxies. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2024-05-05T12:44:01.000 |
| 4486 | 2016.2.00056.S | 62 | Formation of Cores within the Molecular Filaments in the Galactic Center near SgrA* | In our recently delivered 12 m-array HC3N(11-10) and CS(2-1) maps (beam=1.5"), we have found that the giant molecular cloud called 20 MC in the Galactic center consists of multiple dense filaments, which are spatially associated with the magnetic field lines shown in the 20" JCMT-SCUPOL data. In our early analysis, we find that the magnetic field might be dynamically important to stabilize these filaments even though they are below the tidal threshold. We also find that the dense cores traced by the HC3N line are located within these filamentary structures. As indicated by the 20" JCMT-SCUPOL data and the negative strips in our existing 12 m-array maps, we propose the ACA observation to recover the pc-scale structures to combine with our 12 m-array data in order to investigate the kinematic connection between the dense cores and the filaments, as well as the influence of the magnetic field. This will be the first high resolution map to reveal the structures of the dense cores/filaments near the supermassive black hole SgrA*. | Galactic centres/nuclei | Active galaxies | 2019-08-30T00:00:00.000 |
| 4487 | 2023.1.01386.S | 0 | Pristine phase of star formation in a proto-cluster environment | The majority of stars tends to form in clusters. However, the process of star-formation in proto-clusters environment have not been fully understood. A crucial point is the lack of a significant number of observations of the first phases of evolution, i.e. pre-stellar cores, in such regions. From ALMA science archive data we found clumps with one or more fragments clearly detected in 5000 AU resolution data, not detected at higher resolution data (1000 AU). This curious occurrence is likely the signature of the long-sought primordial phase of star formation where a dense very pristine object is formed with no central condensation within it. We propose a study to further investigate this peculiar and rare objects in the most promising clump with 4 cores out of 6 at 5000AU resolution disappearing in the 1000 AU resolution data. We aim to study these extremely pristine cores in this source, using molecular lines that will allow us to determine the temperature, and trace the kinematics and the presence of deuterated species to determine the true nature of this cores. From the results we will have new insights into one of the crucial phases of the star-formation process. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-09-04T17:33:59.000 |
| 4488 | 2022.1.00269.S | 13 | Witnessing Giant Planet Formation in the Act | Observations of giant planets at large semi-major axes (up to 100 au) contrast with the traditional picture of planet formation following the core accretion method most effective in the inner 10 au of disks. Gravitational instabilities at large radii in massive disks have been suggested as a rapid alternative for forming giant planets in the outer disk. We propose to observe Gomez's Hamburger (GoHam) in CO isotopologue emission lines (12CO, 13CO 3-2) and CS 7-6 in Band 7 at 0.15". GoHam is a massive circumstellar disk (Mdisk / Mstar ~ 0.1), which shows an overdensity (GoHam b) with a mass of 1 - 11 M_Jup. The unique edge-on viewing geometry of this system allows for a 3D reconstruction of the disk temperature and density structure using velocity information to infer line-of-sight distances. We will use this 3D reconstruction to directly compare with models of giant planet formation. In addition, the requested spatial resolution of 0.15" will allow us to resolve GoHam b and trace the formation of a giant planet or brown dwarf companion via gravitational instability at local scales. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2025-07-12T22:23:07.000 |
| 4489 | 2022.1.01270.S | 154 | Unveiling the Chemical Complexity at the Edge of our Galaxy | The outer part of our Galaxy is an excellent laboratory to study star formation and interstellar medium in a Galactic low-metallicity environment. The recent discovery of a hot molecular core at the edge of our Galaxy has suggested that a great molecular complexity exists even in a primordial low-metallicity environment of the outer Galaxy. However, detailed chemical compositions of outer Galaxy star-forming cores are investigated only for a single object, and thus their chemical diversity is still unknown. Here we propose ALMA observations to search for hot cores in five star-forming regions in the outer Galaxy, where the metallicity is lower than the solar neighborhood by a factor of at least three. We propose Band 7 observations towards 16 embedded protostar candidates, which were identified by a near-infrared imaging survey with the Gemini-South and IRSF telescopes. This first comprehensive survey of hot cores for the outer Galaxy will provide the community with unprecedented molecular line datasets for low-metallicity star-forming regions in the Galaxy. | High-mass star formation, Astrochemistry | ISM and star formation | 2023-10-18T19:32:25.000 |
| 4490 | 2013.1.00530.S | 136 | A detailed view to the star-forming gas in dusty Herschel-ATLAS galaxies at 0.03 < z < 0.2 | To understand how galaxies consume gas to form stars is a key goal of modern astrophysics. We constructed a sample of 27 galaxies selected from the Herschel-ATLAS survey presenting quality far-IR photometry, including PACS [CII]-158um spectroscopy. Our targets have L_FIR~10^(10.3-11.5)Lo, at 0.0037 galaxies. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2016-05-08T12:40:32.000 |
| 4491 | 2023.1.00564.S | 0 | Gas and Ice: Inheritance or Reset in Taurus planet forming disks? | The abundance and distribution of volatiles in protoplanetary disks is crucial to our understanding of the formation of planets and their habitability. Yet, we still do not known how much of the infalling icy material from the natal cloud makes it unscathed into the shielded disk midplane, and how much of it is reset to its atomic constituents in the gas phase. The gaseous C/H abundance in disks has previously been shown to probe the amount of ices available in the midplane. The recent discovery of Class II sources with late infall facilitates the study of the role of infall on the gaseous and icy chemical inventory in protoplanetary disks. We propose to observe the gaseous carbon abundance tracer [CI] at 492.161 GHz and the C/O ratio tracer CCH in Band 6 in a sample of thirteen protoplanetary disk in the Taurus star forming region, limiting any biases of different starting conditions. Six of these sources have clear signs of infall. By comparing sources with and without infall, at different stages of their evolution, we will trace the level of molecular reset upon infall and the effect that reset has on the amount of ices that are frozen out in disks as a function of time. | Disks around low-mass stars | Disks and planet formation | 2025-10-07T16:27:26.000 |
| 4492 | 2022.1.00342.S | 1638 | Survey of Orion Protostellar Outflow-Envelope Interactions and Evolution | We propose to study the evolution of protostellar outflows and their impact on the dense circumstellar envelope using a sample of 78 low-mass protostars at various evolutionary stages in the Orion A cloud. We will conduct multi-line observations of the environment around these protostars that will allow us to trace the distribution of the outflowing gas (and its momentum and energy) with respect to the kinematics and structure of the infalling envelope. We will use the 12m array and ACA to obtain data with a resolution of 440 au and sensitive to structures extending out to 0.1 pc. Combining the proposed observations with radiative transfer models and MHD outflow simulations we aim to: 1) determine the importance of outflows in the removal of dense gas around protostars and its effect on the star formation efficiency; 2) establish how outflow and infall rates change over the lifetime of prototstars in order to understand their relative impact at different evolutionary stages on the core mass-loss process; and 3) use the results to develop an empirical model of the evolution of the mass-assembling process of protostars that will constrain numerical simulations of star formation. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2024-01-26T18:51:47.000 |
| 4493 | 2016.1.00991.S | 68 | High Resolution Imaging of the Diffuse and Dense Gas in the Early Stage Merging Galaxy NGC 5331 | Under the hierarchical galaxy formation scenario, galaxy-galaxy interaction is believed to play an important role in galaxy evolution, changing the galaxy morphology and triggering star-burst and/or AGN. Recent high spatial resolution (tens of pc scale) numerical simulations have found that tidal interaction is responsible for both merger induced gas inflow (nuclear star-burst) and high dispersion gas of dense gas clump surrounded by diffuse gas cloud (widespread star-burst) in the early stage of the interaction. An observational test of the gas response requires mapping both the diffuse and dense gas tracers at high spatial resolution, especially at early stage interaction. Here we propose ALMA Band 3 observation of the CO, HCN, and HCO+ toward the brightest galaxy in our previous OVRO survey catalog of early stage mergers, NGC5331, at 0.4 arcsec (~ 280 pc) resolution. The primary aim of this study is to observationally confirm the gas inflow toward nuclear regions and the clumpy molecular gas structure with high dense gas fraction in the outer disks. In addition, we will investigate how the distribution of molecular gas evolves along merger stage by using ALMA archival CO image. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2019-09-06T00:00:00.000 |
| 4494 | 2016.1.00437.S | 96 | WISDOM: Extending black hole demographics across the mass-size plane with ALMA | Ubiquitously present at the centres of galaxies, black holes are central to understanding galaxy evolution. However, the current sample of galaxies with measured black-hole masses is incredibly biased, tracing only specific regions of the galaxy mass-size and mass-velocity dispersion planes. As many galaxy properties vary across these planes, this bias could be fundamentally affecting our understanding of black hole scaling relations, and thus the relationship between galaxies and their Super Massive Black Holes (SMBHs). As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) we have pioneered the use of molecular gas to estimate SMBH masses, and conducted the preparatory work required to select a large sample of suitable ALMA targets. Here we propose to map CO(2-1) at high resolution in a sample of objects spanning the unexplored areas of the mass-size plane, accurately measuring their SMBH masses. In this way we can address this bias, extend SMBH demographics, and shed light for the first time on potential variations of SMBH-galaxy correlations using a unique technique (with the same systematics) across the galaxy mass-size plane. | Galactic centres/nuclei | Active galaxies | 2018-09-05T16:07:12.000 |
| 4495 | 2012.1.00357.S | 2 | Star Formation, Shocks and AGN in a Pre-Starburst Galaxy Collision | Starburst activity in galaxy mergers can be driven by various mechanisms such as nuclear inflows, gas fragmentation, and large-scale shocks, and can be balanced by feedback from young stars and/or black holes. The respective role of these mechanisms in boosting the star formation efficiency in mergers remains poorly understood. The galaxies IC 2163 and NGC 2207, in an early pre-starburst stage, offer an ideal laboratory to study all of these phenomena in action. This pair is in a grazing collision that has increased gas turbulence and fragmentation into bright Super Star Clusters, produced galactic-scale shocks, and fueled nuclear activity. It is among the best-observed interactions, with Hubble Space Telescope optical, Spitzer Space Telescope infrared, XMM X-ray, VLA 21 cm emission and 20 cm radio continuum. Detailed simulations have fit over 30 observed features, making it also one of the best modeled interacting systems. Molecular gas observations, previously limited because of the low declination of this system, are necessary to study the distribution and dynamics of the dense gas just prior to an interaction-driven starburst. We propose ALMA observations of a CO(1-0) map plus three HCN(1-0) and HCO+(1-0) pointings of the main representative regions. The data will allow us to measure the molecular gas distribution and kinematics, to spatially resolve excesses of dense gas (using HCN and HCO+), to relate such excess to nuclear inflows, turbulence and/or large-scale shocks, and to compare to local rates of star formation. Observations of these molecules in the nuclei, one with an AGN and one AGN-free, will also make it possible to examine the link between dense gas reservoirs, nuclear star formation and black hole activity. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2015-07-09T18:41:56.000 |
| 4496 | 2017.1.00512.S | 18 | Imaging the Sunyaev-Zel'dovich effect of an X-ray faint massive galaxy cluster discovered by Hyper Suprime-Cam | We propose to observe the Sunyaev-Zel'dovich effect (SZE) of a newly discovered galaxy cluster, HSC J115214+003126 at z=0.47. Our target is the most massive galaxy cluster so far detected with S/N>6 during the on-going weak gravitational lensing survey by Hyper Suprime-Cam (HSC) on the 8.2m Subaru Telescope. Unlike the other clusters already observed via the SZE by ALMA, HSC J115214+003126 does not have any known X-ray counterpart. With the proposed deep observation in Band 3, we aim at i) the first detection of hot gas in this system, ii) unveiling its structure and dynamical status by examining the presence of a cool core and searching for merger shocks, and iii) understanding possible biases in previous surveys. Our proposal serves as the first ALMA-HSC joint study on galaxy clusters. | Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE), Galaxy Clusters | Cosmology | 2019-11-21T17:37:12.000 |
| 4497 | 2017.1.00321.S | 42 | Establishing the Best Tracers of Molecular Outflows Across Redshift and Galaxy Properties | One of the most important realizations of the last fifteen years is the vital role that feedback must play in the evolution of galaxies. Large-scale galactic winds driven by supernovae and/or AGN are often invoked as the means by which feedback occurs. In Cycle 4, we detected massive molecular outflows in several z~4-5.5 dusty galaxies seen in blueshifted absorption of the OH 119um line, the "gold standard" tracer of molecular winds. Due to its high rest frequency, however, this line is difficult to observe at z<4. Here, we propose to establish the effectiveness of two alternative molecular outflow tracers which can be observed with ALMA across essentially all redshifts. Previous observations of these lines have shown a variety of outcomes, from non-detections to full P Cygni profiles, but it is unclear whether the wind non-detections are due to geometric effects or because the lines are not useful tracers. By targeting systems with known winds, we can determine which line is the most faithful tracer in comparison to OH 119um, the best available diagnostic. Finally, due to their formation pathways, the molecules we target will allow us to constrain the wind driving mechanism. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-07-06T16:59:05.000 |
| 4498 | 2016.1.01387.S | 25 | Tracing the history of organic nitrogen: The HCN abundance in a Class 0/I protostar | Where does the Earth's nitrogen come from? What molecular form did this nitrogen take early in the solar system's formation? We propose to address these questions with a study of the molecule HCN in a protostellar system, and to use this to anchor future surveys of nitrogen in protostars and disks. We argue that HCN traces the nitrogen that becomes incorporated into terrestrial planets. In this program we propose observations that will allow us to measure the HCN abundance around a protostar, as well as constrain the evaporation behavior of HCN ice off of dust grains. We will also tightly constrain the geometry of the protostellar system, which, combined with an SED from archival data, allows us to infer the silicate dust distribution via SED modeling. By comparing the measured HCN abundances with the silicate distribution, we can compare N/Si ratios throughout the protostar to N/Si measurements of primordial materials from our own solar system. With the inclusion of subsequent HCN surveys at coarser resolution, calibrated against this program, we aim to trace the Earth's nitrogen through multiple stages of star and planet formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-08-02T23:50:06.000 |
| 4499 | 2022.1.00222.S | 0 | Revealing the magnetic field towards the core of the Circinus galaxy | Extragalactic magnetic fields (B-fields) provide additional pressure to the interstellar medium and intergalactic gas, and couple cosmic rays to the non-relativistic gas. In specific ratios between B-fields and the dynamical and thermal energies of the molecular gas, B-fields may become dynamically important and affect the gas flows and drive the inflows and outflows of a galaxy. A quantitative study of the B-field structure and strength at different physical scales of a galaxy is required to investigate how the material move towards their cores. The nearby active galaxy Circinus has a galactic dynamo in action towards the central engine, where the magnetic stress in the inner-bar and starburst ring may be driving mass inward at the rate needed to fuel the active nucleus. This proposal aims to obtain the spatially resolved multi-scale B-field structure and strength in the central ~100 pc (5) of the starburst ring, mini-spiral, and dusty torus of the Circinus galaxy at resolutions of 2-6 pc (0.09-0.27) using ALMA continuum polarimetry in Band 7. Our ultimate goal is to put empirical constraints to explain the accretion flow to AGN from their host galaxy. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2025-02-21T18:25:26.000 |
| 4500 | 2012.1.00543.S | 7 | Fuelling the Galactic center super massive black hole | The inner few parsecs around Sgr~A* at the Galactic center is likely the best region to understand the physical conditions around a supermassive black hole. Even though this region has been extensively studied at all wavelengths, little is known about the amount and distribution of the densest molecular component within the ~3 pc diameter cavity observed within the circumnuclear disk (CND) of molecular material. In this cavity, ionized material streamers are observed in a ''mini-spiral'' structure. While the ionized gas seems to be associated with the CND on larger scales, we do not have sensitive enough information to establish how the molecular gas is associated with the ionized gas in the central parsec of the galaxy. In this proposal we aim to simultaneously map a set of selected dense gas tracers in their high-J transitions, together with a hydrogen recombination line. This unique dataset will provide us with detailed insight on the physical properties of the molecular gas at the extreme conditions of the very centre of the Galaxy. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2021-03-16T00:00:00.000 |
| 4501 | 2021.1.00483.S | 3 | Dust Polarization in a Large Class 0 Disk: Early Grain Growth or Magnetic Fields for Driving Rotating Outflow? | Per-Emb-14 (NGC 1333 IRAS4C) has one of the largest Class 0 disks discovered at 8mm dust continuum along with a rotating molecular outflow and evidence of differential rotation down to its continuum disk. Previous 870 micron ALMA observations have shown its polarization signature could be produced by scattering of 100 micron grains. However, the polarization can also be explained by grains aligned with the magnetic field. To differentiate between the two scenarios, we propose to observe continuum polarization at Band 4. If the data is consistent with scattering, then grain growth can occur as early as Class 0. If the data supports aligned grains, then it strengthens the case for the magnetically driven disk wind as the origin of the observed rotating outflow. | Disks around low-mass stars | Disks and planet formation | 2024-04-27T13:02:25.000 |
| 4502 | 2016.1.00944.S | 18 | The role of magnetic field in the shaping of planetary nebulae: the extremely young planetary nebula K3-35 | Several theoretical models have pointed out the role of magnetic fields in shaping pre-planetary nebulae and planetary nebulae. Indeed they would be responsible for the presence of strong outflows and jets via magnetic launching for example, that would carve the nebular envelopes. However the observations supporting these findings are still scarce. In order to better understand the evolution of magnetic fields and their role in the PNe shaping we propose to study the PN K3-35. This is a very young bipolar object just entering in the PN phase and where a magnetic field has been measured via OH maser polarization; but there is no information on the geometry of the field. With ALMA in polarimetric mode and at high resolution we intend to map the polarized dust continuum at 345 GHz and unveil the distribution of the magnetic field. The latter will be compared to the different structures present in the PN (precessing jets, bow-shocks, torus) to look for any correlation. K3-35 would then be the first very young PN for which and accurate image of the magnetic field geometry (and then a clearer assessment of the dynamical importance of this field) would be available. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2019-12-20T15:49:01.000 |
| 4503 | 2024.1.01197.S | 0 | First Dynamical and FIR Characterizations of an X-ray luminous AGN host galaxy at z > 10 | Young QSOs at z>10, as progenitors to luminous QSOs so far found out to z=7.6, preserve key information of the rapid growth of massive BHs and the co-evolution with their hosts. Whereas their identifications and characterizations had been hampered by observational limitations, a highly lensed X-ray luminous AGN host galaxy was recently spectroscopically confirmed at z=10.07 with JWST/NIRSpec. Here we propose ALMA follow-up of [CII]158um, [OIII]88um, and the underlying dust continuum for the host, UHZ1, a young (Muv= -19mag) star-forming galaxy. Notably, the current MBH/Mstar estimate from the joint Chandra+JWST studies suggests the heavy seeding channels for the early massive BH origins, while ALMA affords the unique opportunity to verify the scenario from an independent dynamical mass estimate. We will 1) investigate dynamical and cold/hot ISM properties via the [CII]&[OIII] lines, and 2) constrain the dust-obscured star-forming activity in the host. UHZ1 also shows a marginal dust emission in the latest ALMA 1mm map, having a great potential of leading to the first dust detection at z>10 and revisiting the mechanisms of early dust production, growth, and destruction. | Lyman Break Galaxies (LBG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2025-10-24T09:37:28.000 |
| 4504 | 2016.2.00105.S | 663 | Nature of Herschel-Selected Distant Starbursts | Herschel has uncovered a population of extremely rare, bright, typically gravitationally lensed submillimeter galaxies (SMGs), making them strongly-magnified versions of the most intense starbursts throughout cosmic times. Using short observing blocks as an ACA "time filler", we here propose to observe 38 high-J CO lines toward a sample of 19 Herschel-selected SMGs detected in "blind" CO searches, also covering [CI] and high-level H2O lines "for free". This will enable us to study the excitation of the warm gas in the star-forming regions and the starburst nuclei of these intriguing systems, and to investigate the relevance of differential gravitational lensing for the determination of CO line intensity and line width ratios. This will also allow us to fully place them into context with SMGs selected at the traditional, longer submillimeter wavelengths (e.g., ALESS, SPT). This comprehensive program will substantially improve our understanding of the physical properties of and diversity among the most intense starbursts throughout cosmic history, providing key constraints on their importance for early massive galaxy formation. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2018-10-31T13:34:45.000 |
| 4505 | 2021.1.00701.S | 12 | High angular resolution molecular and dust images of Supernova 1987A | Supernova (SN) 1987A is a unique SN, which modern telescopes can spatially resolve at wavelengths ranging from X-ray to radio. Its time evolution has been monitored over 30 years, revealing in remarkable detail how a SN has transformed into a SN remnant. For the cycle 8 program, we request deep high-angular resolution images of SN 1987A in bands 6, 7 & 9, covering SiO 6-5, SiO 7-6, CO 6-5 and dust 450-micron and 850-micron emission. The combination of these images will give temperature and column density maps of dust and SiO. Furthermore, SiO and CO data provide the 3-dimensional velocity maps of these molecules. With these images, we will investigate four science cases: (1) investigating molecular and dust chemistry operating in the SN ejecta (2) characterising the nature of the emerging neutron star (3) probing interaction between ejecta dust and reverse shocks, and (4) investigating the proper motion of clumps in the ejecta. | Post-AGB stars | Stars and stellar evolution | 2022-11-08T12:36:05.000 |
| 4506 | 2012.1.00482.S | 2 | The cold debris disk in the unique multi-planetary system around HR 8799 | HR 8799 is the only multi-planet system with direct imaging available, and its debris disk is a prime ALMA target to understand how planetary systems form and evolve. We propose to observe continuum emission of the cold debris disk of HR 8799 at 230 GHz (Band 6) in order to (1) determine the disk structure probing for signatures of resonant structures, asymmetries and spiral structure; (2) constrain the unknown disk inclination; and (3) determine accurately the inner disk edge. We will determine the disk structure with unpredecented accuracy and will compare the observed structure with the predictions of models. The data will be combined with matched resolution data at 345 GHz (Band 7) from a Cycle 0 progam if it gets completed. The two datasets will allow to contrast the disk at two different wavelengths, allowing tighter constraints on the nature of any observed structure. Finally, our program will provide a first epoch at 230 GHz for the exploration of orbital motion of any observed structures. | Debris disks | Disks and planet formation | 2016-06-09T20:31:40.000 |
| 4507 | 2021.1.00828.S | 18 | Validating the range of D/H ratios in our Solar System's primitive H2O reservoir | The deuterium-to-hydrogen fraction (D/H) in cometary water ice is a crucial diagnostic for the possible contribution of comets to the Earth's water budget, but the average D/H ratio in the comet population is not well constrained due to (1) a lack of sufficiently sensitive ground-based measurements, and (2) a large apparent spread in the values from past observations. We aim to address this issue with the first study of cometary HDO using ACA observations of the very strong 1,1,1 - 0,0,0 line, which is uniquely accessible in ALMA Band 10, allowing the HDO abundance to be measured with unprecedented sensitivity. Our measurements of D/H in comet 67P during its extremely favorable 2021 apparition will provide a "ground truth" test of the unexpectedly high D/H value measured in this comet by the Rosetta spacecraft. We will also measure D/H for the first time in the (predicted) bright Oort cloud comet (OCC) C/2021 A1 (Leonard), to obtain the most accurate D/H value ever obtained in an OCC from the ground (or to determine the most stringent upper limit to-date), with the potential to transform our understanding regarding the origins of cometary and terrestrial water. | Solar system - Comets | Solar system | 2024-02-08T20:48:29.000 |
| 4508 | 2022.1.00438.S | 100 | Resolving the CO2 snowline in the protostellar envelope of L483 | Carbon dioxide (CO2) is an abundant species in interstellar ice and the Solar system bodies and one of the dominant carriers of carbon and oxygen. Observationally locating the CO2 snowline in planet-forming regions is crucial to understanding how CO2 in the ISM will be incorporated into planetary bodies. However, as the direct observations of gas phase CO2 are challenging, the distributions of CO2 in the protostellar envelopes are still poorly understood. We propose to observe multiple molecular lines of protonated carbon dioxide (HCO2+), the gas phase CO2 tracer, to locate the CO2 snowline and probe the distributions of gaseous CO2 in the typical protostellar envelopes of L483 by spatially resolving the CO2 sublimation region. The proposed observations will provide fundamental insight into the CO2 chemistry in planet-forming regions and the Solar system and critical benchmarks for existing astrochemical models and future HCO2+ observations. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-12-28T08:14:29.000 |
| 4509 | 2017.1.01140.S | 54 | Radio-Mode AGN Feedback on the Molecular Gas in the Merger Remnant Fornax A | We propose to image CO(2-1), CO(3-2) and 870um emission in the disturbed merger remnant elliptical NGC 1316. This galaxy is a superb nearby laboratory for studying the critical, but poorly understood, process of radio-mode AGN feedback in the aftermath of a galaxy merger. The iconic HST image shows remarkable disturbed dust clouds that may be associated with different phases of AGN feedback. With ALMA, we aim to study the molecular and dust emission from these clouds to characterize their physical characteristics. Some are seen where the radio jets bend, and an unusual V-shaped nuclear dust cloud may be a source for an AGN-driven molecular outflow. Several kpc from the center and far from the jet and there are elongated dust clouds with quasi-radial alignments, strongly suggesting disrupted dense gas throughout the inner galaxy. We will measure the gas and dust masses, kinematics and CO excitation of these structures, and map the spatial variation of the SFE. We will therefore ascertain the physical nature of the AGN-driven ISM disturbances seen in HST, and whether there are local SFE variations connected to these that may provide clues as to the nature of the radio AGN feedback. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2020-06-22T00:00:00.000 |
| 4510 | 2023.1.01196.S | 0 | A complete ALMA study of AGN in Nearby Major Galaxy Mergers at <5kpc Nuclear Separations | We propose to obtain high-resolution, 0.1", band 6 ALMA observations for a complete sample of nearby, z<0.05, AGN hosted by major galaxy mergers with <5 kpc nuclear separations, selected at ultra-hard X-ray energies from the BASS all-sky survey. Our first goal is to search for unresolved nuclear continuum emitters indicating the presence of at least one growing supermassive black hole (SMBH) in these systems and measure their accretion rate. Then, we will use the CO(2-1) emission line to study the molecular gas' physical properties in their nuclear regions, allowing us to (i) study the dynamics of the molecular gas around each SMBH, (ii) constrain key gas parameters for SMBH feeding, (iii) spatially resolve the molecular gas, and (iv) identify potential nuclear molecular outflows. Our final sample of 12 systems will more than triple the number of AGN in near-coalescence major galaxy mergers with unprecedented high-resolution ALMA observations. It will contain both single and dual AGN, allowing us to study structural differences in their nuclear molecular gas properties, thus providing key inputs for SMBH growth, galaxy evolution, and the generation of gravitational wave events. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2024-11-08T22:51:21.000 |
| 4511 | 2017.1.01205.S | 90 | The Role and Origin of Dust in a Feedback-Induced BCG Starburst | We propose to acquire spatially resolved imaging with ALMA of the dust continuum in the brightest cluster galaxy (BCG) of the galaxy cluster MACS1931.8-2635, to a depth of 0.044 mJy using a combination of observations in bands 6 and 7. These ALMA observations will, for the first time, map both gas and dust at 0.6" (3 kpc) scales in conjunction with acquired and pending CO(1-0) data, comparable to the size scales of the UV-bright star forming knots and dust lane width in this system. With these data, we will determine the sources, and distribution mechanisms, of dust in cooled gas in this BCG, characterize the interaction between dust and molecular gas flows detected in this system, and constrain the role of dust as a catalyst for star formation and intra-cluster medium cooling. By combining this unique ALMA observation with our Cycle 4 observation of CO and with deep observations from HST, Spitzer, Herschel, Chandra, and archival MUSE IFU data, we will complete a comprehensive study of the multi-phase medium in MACS1931 that will answer unsolved questions about the origin of dust in cool core BCGs and the role of gas physics in AGN-regulated feedback and star formation. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2019-06-20T14:38:55.000 |
| 4512 | 2017.1.01323.S | 54 | Unveiling chemical compositions of high-mass star-forming cores in low metallicity galaxies | Interstellar chemistry in low metallicity environments is crucial to understand chemical processes in the past universe. Prior to this proposal, we conducted spectral line surveys toward molecular clouds in nearby low metallicity galaxies, LMC and SMC, with single-dish telescopes. As a result, we found that molecular clouds in LMC experience chemical processes different from those in our Galaxy. However, the beam size of single-dish telescopes (5-10 pc at LMC) is too large to resolve internal structures of molecular clouds, and emission from star-forming cores (~0.1 pc), which reflect the chemical compositions of molecular gas associated with newly formed stars, is almost diluted out. Here we propose ALMA band 6 and 7 spectral line observations toward high-mass YSOs in LMC/SMC to unveil the impact of low metallicity environments on chemistry of star-forming cores. This proposal should elucidate a possible link between chemical properties of dense molecular gas and metallicity of the host galaxy. Furthermore, this program has potential to identify a hot molecular core in external galaxies, which should help understand chemical diversity of complex molecules in our universe. | Astrochemistry, Magellanic Clouds | ISM and star formation | 2019-10-19T22:19:19.000 |
| 4513 | 2018.1.00486.S | 44 | The most massive molecular outflows seen at GMC/A scales: ULIRGs at 45 mas | Star-formation (SF) and AGN feedback are key actors in the evolution of galaxies. Negative feedback regulates both the growth of the stellar mass and the massive black-holes in the bulges of galaxies. Its most evident signature is the universal presence of massive outflows in active galaxies. In this proposal, we aim to study the stellar feedback (which is thought to be dominant class of feedback for most galaxies) in a small sample SF-dominated ULIRGs (ie the strongest local starbursts hosting massive outflows) for the first time at the relevant giant molecular cloud associations (GMC/A) and giant HII regions scale where feedback occurs. We propose high-spatial/angular resolution (~65 pc; 45-80 mas) CO(2-1) observations of 4 of the brightest SF-dominated ULIRG systems (6 nuclei) where we have characterized spatially resolved massive molecular outflows using ALMA and PdBI data. Our main goals are: (1) resolve the molecular clumps in the ULIRG disks and compare them to those found, at similar scales, in objects with lower SF to identify the feedback effects; and (2) establish the outflow sub-structure and locate potential clumps where SF could be present (ie positive feedback). | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2020-12-26T04:20:49.000 |
| 4514 | 2019.1.01472.S | 9 | Self-similar fragmentation of cold cores on the verge of forming massive stars? | Initial conditions of massive star formation are largely unknown due to the lack of observational constraints. Significant efforts have been made in hunting for massive prestellar cores, but are strongly biased to protostellar objects. Our existing ALMA observations guided by the CARMA NH2D maps successfully caught cold, massive, and highly sub-virial cores that are on the verge of forming stars. We found that these prestellar cores fragment into entities following a mass-size relation in surprising consistentency with a column density of 1 g/cm^2. To put stringent constraints on the internal structure of prestellar cores that give rise to massive stars, and to address whether the cores fragment all the way down to the thermal Jeans limit, we propose for followup ALMA Band 6 observations of the two NH2D cores in dust continuum and N2D+/DCO+ (3-2), CO (2-1), SiO (5-4) lines. The requested sensitivity and resolution are determined by an analysis of the existing data, and thus promise to make breakthrough or at least provide significant new insights in the initial conditions of massive star formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2021-06-16T15:39:17.000 |
| 4515 | 2012.1.00885.S | 3 | Obscured star formation and cold gas in most distant dense environments: cluster galaxies in the core of Cl J1449+0856 at z~2 | We propose to observe continuum emission at 345GHz (restframe ~300um), and the CO[3-2] line, from galaxies in the core of the z~2 galaxy cluster Cl J1449+0856. In a redshift range which is generally typical of proto-clusters rather than established clusters, this is the most distant cluster discovered to date with detected X-ray emission, and hosting in its core a population of quiescent early-type galaxies, thus suggesting an already evolved structure. The discovery of this rare object, and the ALMA cycle 1 capabilities, give us the chance of studying, for the first time in such detail and at a such early epoch, star formation in normal (sub-M*) galaxies in a forming cluster core, the prototypical biased environment for galaxy evolution. The proposed observations will be able to probe obscured star formation, and the gas reservoirs that fuel it, for the normal galaxy population (SFR down to 40 Msun/yr, stellar masses of order log(M/Msun)~10). Their resolution will be a crucial advantage in the crowded field typical of a cluster core. ALMA capabilities in terms of sensitivity and spatial resolution thus very well match the science goals of this project. Furthermore, the extensive supporting data set on this field (including data from VLT, HST, Subaru, Spitzer, Herschel, APEX, SMA, IRAM PdB, and JVLA), will significantly enhance (and in turn will be enhanced from) the proposed ALMA observations, maximising their scientific return. Our main goal is the first-time mapping of star formation and cold gas in normal cluster core galaxies at z~2. In combination with the available data set, this will provide immediate insight on the mass-dependent star-formation activity in most dense environments at a crucial epoch in the formation/evolution of cluster galaxies. By comparison with analogous measurements for field galaxies at similar redshift, this will also lead to a direct assessment of environmental effects on gas reservoirs, and of the enhancement or suppression of star formation, in the densest regions at early cosmic times. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2015-12-18T16:42:31.000 |
| 4516 | 2012.1.00033.S | 2 | Demonstrating ALMA's Capabilities with the Luminous Giant Starburst 'Himiko' | We propose Band 6 observations of the giant starburst galaxy 'Himiko' at z=6.595 discovered by our panoramic Subaru survey in the UDS field. This remarkable object, free from strong AGN activity, is unique in its high star-formation rate (100Mo/yr), large stellar mass (2x10^10Mo), and luminous Lyman alpha nebula which extends over 17 kpc. Most likely Himiko is being seen at a special time in its history and thus it provides a natural laboratory for studying the physical processes that govern the assembly of massive galaxies. Our recent HST observations reveal a complex morphology with 3 stellar knots suggestive of a major merger. However, the origin of the extensive ionized nebula is unclear: it could be produced by an energetic superwind or via cold gas accretion along filamentary structures. Our Cycle 1 ALMA observations will considerably extend any data we receive from our approved Cycle 0 program. Specifically, with the spatial resolution same as our HST data (0".2), they will resolve the structure in this remarkable object revealing the dynamics of each knot using the [CII] 158um line and defining the amount of obscured star formation through a 1.2mm continuum image. The combination will address the origin of Himiko's intense luminosity and the power source for the large surrounding nebula. In conjunction with the large set of ancillary data following our original discovery of this system, our proposed observations will showcase the capabilities of the early ALMA array via the first view of how the most massive galaxies formed close to redshift frontier of z~7. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2016-10-22T19:02:07.000 |
| 4517 | 2012.1.00196.S | 2 | Central Mass Accumulation in Dense Cores and the Origin of the Circumstellar Disk | When dense cores contract or collapse, mass will accumulate at the core centers. Furthermore, angular momentum will shape this mass into flattened structures that feed growing protostars. Theoretical studies of this early epoch have called the larger, non-Keplerian structures that arise "circumstellar accretion regions" (CARs) or "pseudodisks" and the smaller, Keplerian structures "early disks." These studies, however, have been never constrained by actual observations because previous interferometers have not had the combination of mass sensitivity to detect small-scale (~100 AU) structure within dense cores. We propose with ALMA to observe Band 7 continuum emission from 5 dense cores each on the brink of star formation, to detect these flattened structures at high mass sensitivity (1-5 x 10^-4 Msun) and high linear resolution (90-200 AU). These data will be further supplemented by simultaneous observations of the dense gas tracers H2D+ 1_10-1_11 and N2H+ 4-3, to explore the kinematics and chemistry of these dense precursors to disks. Together, these data will reveal the central accumulation of mass and characterize the origins of disks for the first time. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2016-09-25T02:42:35.000 |
| 4518 | 2019.1.00566.S | 24 | An Unbiased Survey of Disk Structures and Planet Formation around Very Low-mass Stars in Taurus | Correlations between protoplanetary disk properties and stellar mass are frequently applied to infer initial conditions and evolutionary processes of disks. High-resolution ALMA images of dust disks reveal that some disks are large and exhibit exquisite substructures, while others are small and may lack substructures. Since most of these are images of disks around 0.5-2 Msun stars, the stellar mass range is insufficient to use as a lever arm for correlations of disk morphology versus stellar mass. We request high resolution (0.04") images of 16 low-mass (0.1-0.3 Msun) T Tauri disks, unbiased to substructures and mm-brightness, to evaluate the differences in the dust morphology in disks versus stellar mass. The ultimate goal is to understand how the differences at the disk stage relate to differences in the population of exoplanets around very low-mass and solar-mass stars. The sample is complete for disks around M3-M5 stars, with selection criteria for extinction, known binaries and declination. These observations provide an important complement to our unbiased sample of disks around solar-mass stars in Taurus as well as to high resolution results from other surveys. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2022-09-07T22:17:50.000 |
| 4519 | 2017.1.00492.S | 38 | DETECTING THE CIRCUMPLANETARY DISK AROUND THE SPIRAL-ARM-DRIVING PLANET IN A PROTOPLANETARY DISK | We propose Band-7 observations of MWC 758, a protoplanetary disk with a remarkable pair of spiral arms detected at near-infrared (NIR) wavelengths, with an 0".05 angular resolution to look for signatures from the circumplanetary disk (CPD) around the planet MWC 758 b, as well as to characterize the spiral arms. The planet was predicted by our models as the driver of the arms, and has very recently been detected in our Keck/NIRC2 NIR adaptive optics (AO) imaging observations at ~4.5-sigma level. The proposed observation is based on detailed simulations of the system, and presents the most promising opportunity to result in the first definitive detection of a CPD in a disk. Once detected, this will be the first feature-producing planet quantitatively predicted by disk-planet interaction models, and will likely open another door in planet detection. Still forming in gaseous disks, this planet will be among the youngest discovered, and will help address two fundamental questions in planet formation: where and when do gas giant planets form. | Disks around low-mass stars | Disks and planet formation | 2019-10-12T16:09:12.000 |
| 4520 | 2018.1.01104.S | 34 | New Light in the Dark Heart of Cygnus A | Cygnus A is the iconic radio galaxy, composed of two luminous radio jets emanating from a QSO-like nucleus buried within the dense, gas- and dust-rich center of a massive early-type galaxy at z=0.056. Our recent low-frequency observations have uncovered a surprise: a serendipitous 3 mJy radio transient located 0.4" (450 pc) from the nucleus that appeared sometime between 1997 and 2015. This object could originate from an exotic luminous supernova, or could be a flare from a previously-unknown secondary supermassive black hole. The radio SED of the transient exhibits a flat spectrum at low frequencies and an apparent power-law extending to higher frequencies but has not been characterized above 50 GHz. We propose for ALMA observations to extend the SED to millimeter and submillimeter wavelengths to look for an additional high-frequency emission component that may be present. As a byproduct of our observations, we also expect to produce the first submillimeter image of the inner Cygnus A jet, and map out any dust emission from star clusters present within the LIRG-like galaxy core. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2020-10-23T01:25:00.000 |
| 4521 | 2015.1.01060.S | 42 | Identification of the Centrifugal Barrier of the Infalling Rotating Envelope in the Hot Corino Source IRAS 16293-2422 | With the ALMA Cycle 0 observations, we have discovered the centrifugal barrier of the infalling rotating envelope in the Class 0 protostar IRAS 04368+2557 in L1527. This source is known as the warm carbon chain chemistry source harboring rich carbon-chain molecules. Since the centrifugal barrier is expected in other protostars regardless of its chemical characteristics, we here propose to identify it in another Class 0 protostar IRAS 16293-2422, which is known as a hot corino source harboring rich saturated complex organic molecules (COMs). We have already have a hint of the centrifugal barrier in this source from our analyses of the archival data of eSMA and ALMA SV, and we are going to verify it at a high angular resolution with ALMA. It is most likely that the accretion shock around the centrifugal barrier contributes to enhancement of COMs in this source. This observation will address a long standing question what the hot corino is, which has a substantial impact in astrochemistry and astrophysics. | Low-mass star formation | ISM and star formation | 2017-04-12T08:28:31.000 |
| 4522 | 2016.1.00881.S | 32 | What Stops Galactic Star Formation? An ALMA Study of Dense Molecular Gas in Post-Starburst Galaxies | We have identified a unique sample of post-starburst, post-merger galaxies, in transition between late- and early-types. Remarkably, we have discovered molecular gas in over half the sample, forcing these galaxies off the classical Kennicutt-Schmidt relation. In other words, they have significantly higher molecular gas surface densities than predicted by their star-formation rate (SFR) densities. Our cycle 3 ALMA observations have now constrained the CO (2-1) emission to be within only 1.5 kpc from the center in the post-starburst galaxies observed thus far. This discovery suggests a lower star formation efficiency than for normal star-forming galaxies with the same gas densities, making post-starburst galaxies a new laboratory for linking the physics of star formation on small scales to galaxy-wide trends. Only ALMA can measure the actual fuel for star formation, the denser gas traced by HCN, HCO+ and HNC, to determine what is preventing stars from forming. Here, we propose study the dense gas content of two post-starbursts with measured compact gas reservoirs. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2018-05-15T17:32:55.000 |
| 4523 | 2017.1.01424.S | 24 | 3D tomography in protoplanetary disks with spiral density waves | Spiral arms have been observed in ten protoplanetary disks in near-infrared scattered light and now also in the sub-millimetre. They were interpreted as signatures of the interaction between the disk and a planetary or stellar companion, even though such companion have been detected in only one system, HD100453 the target of this proposal. We thus propose to observe the young spiral-bearing disk around HD100453 with ALMA to detect the sub-millimetre counterpart of the spirals seen in scattered light. Since the pitch angle of spiral waves depends on the temperature via the sound speed, the comparison of the spiral pitch angle in ALMA continuum and in SPHERE scattered light images can provide us a new method of studying the vertical thermal stratification in the disk. While the pitch angle vary with height above the disk mid-plane, spirals at all layers converge towards the perturber exciting them. Thus the comparison of SPHERE and ALMA observations of spirals can also provide us information on the location of the perturber, which we wish to study in HD100453. Such technique would be an immense help in the search for the perturber in other systems where the perturber is unknown. | Disks around low-mass stars | Disks and planet formation | 2019-01-06T11:50:15.000 |
| 4524 | 2023.1.01651.S | 0 | Testing the time-dependent chemistry of complex molecules in the expanding CSE IRC+10216 | The latest, high sensitivity, spectral line surveys of the TMC1 dark cloud and the IRC+10216 envelope, made with single-dish telescopes, have revealed an amazing wealth of complex organic molecules: long aliphatic chains and aromatic rings. Yet, the environment in those sources is notoriously unfavorable to the formation of such molecules and current gas-phase astrochemical models fail to reproduce the high abundances observed for some species by several orders of magnitude. Time, a key parameter of the chemistry, is however ill constrained in these low spacial resolution observations. We propose to use the uniform expansion of the outer IRC+10216 envelope to map with a 1 arcsec (i.e. 40 years) resolution the emission of many critical species identified in this source and accurately measure their formation and destruction times, setting tight constrains to the chemical models. In particular, the question of whether complex molecules form from bottom-up (e.g. radiative association) or top-down (desorption from grains) processes will be open to investigation. | Evolved stars - Chemistry | Stars and stellar evolution | 3000-01-01T00:00:00.000 |
| 4525 | 2016.1.01515.S | 175 | Revealing Major Mergers Among the Extreme Star Forming Hosts of the Fastest Growing Super-Massive Black Holes at z=4.8 | We propose to resolve the host galaxies and close environments of fast-growing Super-Massive Black Holes (SMBHs) at z~4.8, which would likely become the most massive BHs known (M_BH>10^10 Msun) before z~4. Our Herschel observations show that these SMBHs are hosted in intensely star-forming (SF) galaxies with a wide range of SFR, exceeding ~2000 Msun/yr in ~1/4 of the systems. The goal of this ALMA project is to determine whether the AGN and SF activity is driven by major galaxy mergers or other, secular mechanisms. Preliminary results from our cycle-2 pilot study demonstrate that ALMA provides the best way to test this scenario, by probing the distribution of gas and SF in the QSO hosts and interacting galaxies, on ~2 kpc scales. The continuum emission maps will resolve any star-forming galaxy, down to 100 Msun/yr. Using the luminous [CII]158um line we will: (1) identify interacting companion galaxies; (2) probe the ISM dynamics of the QSO hosts, merger signatures; and (3) estimate the hosts dynamical masses and M_BH/M_host ratios. Thus, ALMA will provide key insights into the early and rapid (co-)evolution of SMBHs and their host galaxies, for a sizable, well-defined sample. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2017-12-16T17:39:37.000 |
| 4526 | 2016.1.00187.S | 18 | Magnetic Fields and High-Mass Star Formation | We propose to map the continuum, CO, and CN linear polarization of the molecular cloud G10.6 in order to study the magnetic field in this high-mass star forming region. Continuum polarization maps will provide information about the magnetic field morphology averaged through the optically thin dust emission. Spectral-line linear polarization is produced by the Goldreich-Kylafis effect and traces the magnetic field morphology in regions where the spectral lines have optical depths of order 1 and the excitation is radiatively dominated. CO line polarization has been detected in a number of sources, but CN has not. However, the dust, CO, and CN observations will be performed simultaneously, without loss of observing time if CN polarization is not detected. The sensitivity of ALMA makes detection of CN linear polarization a definite possibility. In addition to maps of magnetic field morphology at different shells within the molecular cloud, magnetic field strengths will be inferred using the Chandrasekhar-Fermi technique. This project will provide a detailed study of the magnetic field in this molecular cloud and of the role of magnetic fields in the high-mass star formation process. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-07-20T15:58:59.000 |
| 4527 | 2015.1.00055.S | 74 | Quantifying the Role of Environment in Star Formation: ISM masses along the Cosmic Web with ALMA | We propose an experiment to test the role of environment in star formation; we will measure the ISM masses (and the average excited gas) for 101 high redshift star-forming galaxies along the cosmic web. The large area of the COSMOS survey coupled with extensive redshifts has enabled mapping of the large scale structure. We focus our study at z~0.7 where the widest range of environments are seen, and near the beginning of the peak epoch of star formation. Using the galaxy density maps, we select spectroscopically-confirmed infrared galaxies across a range of environments (controlling for stellar mass and star formation rate). We propose to measure the submillimeter continuum flux, which will be adopted as a surrogate for the ISM mass based on a well-tested, empirical relation. We will use these data to quantify how the ISM mass depends on the local galaxy density. In addition, we will stack the rest-frame spectral data in bins of galaxy density to measure the evolution in average excited gas immediately available for star formation. This simple experiment will allow us to constrain the role that environment plays in star formation activity by moderating the ISM and excited gas. | Galaxy Clusters | Cosmology | 2017-11-21T21:25:45.000 |
| 4528 | 2012.1.00195.S | 0 | Molecular Gas in Debris Disks: Resolving the Disk around 49 Ceti | The dispersal of primordial gas and dust from debris disks sets the timescale for planet formation and is closely intertwined with our understanding of the physical processes that shape planetary systems. While it is generally assumed that molecular gas dissipates before the debris disk stage, the nearby A star 49 Ceti is one of only three systems known to host a tenuous, second-generation debris disk while still retaining a substantial molecular gas reservoir. As the oldest, closest, and best-studied of the three, it is the best target for detailed follow up to elucidate the excitation, chemistry, and kinematics of the gas and dust, as well as to determine whether the gas is primordial or released from evaporating comets. SMA observations in the CO(2-1) line hinted at a surprisingly complex and extended gas disk, but were not sensitive enough to detect continuum emission from the dust. Here we propose to spatially resolve the dust disk for the first time and improve upon the molecular gas observations by an order of magnitude in both sensitivity and spectral resolution. Our objectives are the following: (1) By spatially resolving the dust disk, we will determine whether the gas traces the dust, providing unique insight into the relative dispersal rates and processes of the gas and dust components. (2) By observing CO(3-2) emission at high spectral and spatial resolution we will measure the temperature and density structure of the gas disk and the gas-to-dust ratio. We will also examine the disk kinematics in exquisite detail, following up on the deviations from Keplerian rotation hinted at by the SMA observations. (3) HCN observations in combination with thermo-chemical disk models will allow us to investigate the anomalous C/O ratio hinted at by Herschel observations, and to determine whether the molecular gas is primordial or second-generation (cometary). ALMA's unprecedented sensitivity and resolution will allow us to address basic questions in a field that is starved for information about the enigmatic liminal stage between protoplanetary and debris disks. | Debris disks | Disks and planet formation | 2015-01-30T04:13:00.000 |
| 4529 | 2018.1.00490.S | 210 | Search for Molecular Absorption Lines in the Host Galaxy of High Redshift AGNs | Molecular absorption lines seen towards high redshift QSOs provide superior sensitivity compared with emission line studies and provide a mean of gaining detailed knowledge about the physical and chemical properties of molecular gas at high redshift. This has been demonstrated with the 5 known molecular absorption line systems at redshifts =0.25-0.9. Molecular absorption is, however, rare and its usefulness is curtailed by the small number of absorbing systems known. With this proposal we aim at searching for molecular absorption lines in 20 carefully selected sources. We target host galaxies of radio-loud AGNs that have known redshifts and indications of obscuration. Selecting host galaxies rather than intervening galaxies ensures that the impact parameter is zero and the likelihood for absorption increases dramatically. The detected systems will be followed up with detailed studies of their molecular ISM. The observing strategy targets absorption lines in ALMA band 3 and is very modular in design. Our sources are distributed all over the southern sky and each SB can be executed in 23-38 minutes. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2019-11-14T15:55:31.000 |
| 4530 | 2019.1.00313.S | 390 | Needle in a haystack: Identifying the highest-redshift candidate DSFGs using 2mm imaging | Dusty Star-Forming Galaxies dominate cosmic star-formation at its peak (z~2) and yet little is known of their volume density toward higher redshifts, where their existence may place interesting constraints on the formation of massive galaxies (M*>10^11Msun). Our empirical modeling suggests that 2mm imaging of existing, bright samples of DSFGs selected at 850um-1mm can quickly and easily separate DSFGs by redshift, isolating the `needle in the haystack' DSFGs that sit at z>4 or beyond. We propose 2mm dust continuum observations of a sample of 453 of the brightest SCUBA-2 850um-selected DSFGs (S850>5mJy) with the goal of: (1) identifying the highest redshift candidate DSFGs for future follow-up with ALMA spectral scans and JWST, (2) using DSFGs' 2mm flux densities as a sanity check on the robustness of their optical/near-infrared multiwavelength counterparts, (3) inferring the volume density of z>3 DSFGs using the population's distribution in 2mm flux density combined with our models of (sub)mm emission from obscured galaxies, and (4) refine measurements of beta, the dust emissivity spectral index for a wide range of DSFGs to improve our understanding of galaxies' dust SEDs. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-04-24T15:24:18.000 |
| 4531 | 2019.1.00703.S | 63 | Investigating Disk Disruption and Mass Outflow Triggered by Binary Orbital Motion: The Important Case of T Tauri South | T Tauri is the eponymous member of it's class of young sun-like stars. This remarkable triple star system has become a veritable laboratory for modeling dynamical evolution in young multiple systems. H alpha imaging of its outflows reveals periodic mass ejections. Correlation of the imaging and outflow kinematics with the historical orbit timing of T Tau South binary (period 27 yr) suggests a fascinating prospect: the launch of the five southern outflow ejections may be nearly contemporaneous with the close-binary periastron passage. As such, T Tau provides an amazing opportunity to witness circumstellar tidal disk disruption, and launch of a new outflow with the upcoming binary periastron passage in 2023. With 10 hours of ALMA time, we propose to make a pre-periastron measurement of the T Tau system. Cycle 7 is the last opportunity to make a detailed inventory at high resolution of the circumstellar gas and dust (inner and circumbinary disks, jets/outflows) in the quiescent phase. This will provide a crucial step to unambiguously establish the driving mechanisms that will trigger enhanced accretion and new, predicted mass outflows. | Intermediate-mass star formation | ISM and star formation | 2022-11-16T15:18:29.000 |
| 4532 | 2015.1.01040.S | 4 | Search for CO-Dark Mass within the Milky Way's Circumnuclear Region | Increasing evidence for star formation in the circumnuclear region of the Milky Way has been reported, despite the hostile environment for star formation. Meanwhile, complete knowledge about the distribution and kinematics of the molecular gas in the central parsecs is hampered by the extreme physical condition there, where the most commonly-used molecular mass tracers, namely CO rotational lines, might function less efficiently. One biggest mystery is how much molecular gas are present there and how the stars can form against the strong tidal field created by the nucleus, to which the answer remains unsettled. Our recent observations of the atomic carbon (C^0) [CI] line have found evidence for the atomic carbon dominates the carbon-bearing species in the central few pc region, whose relative abundance to CO exceeds unity, invoking a speculation that the molecular mass there are occupied by CO-dark mass. We propose a [CI] imaging of the central 5 parsec region of the Galactic center, to delineate the molecular mass distribution and thereby investigate the star formation activity in the innermost region of the Milky Way. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-06-09T00:00:00.000 |
| 4533 | 2021.1.00766.S | 91 | Constraining the cold accretion onto the most massive Black Holes | The properties of the cold gas found in the cores of clusters of galaxies are relatively poorly constrained. Observations of the global emission from the ensemble of cold clouds traced by CO allow us to estimate the total mass and overall temperature of the gas. However, without information about the size, density, and chemsitry of individual clouds, it is not possible to unambiguously determine how they fuel AGN activity. We propose to obtain CO(2-1), CN(2-1), H2CO(3-2), HCO+21-1), and HCN(2-1) absorption observations toward the cores of eight sources which already have strong CO(1-0), CN(1-0), or HI absorption lines. This will provide the properties of a statistically meaningful sample of these clouds. | Galaxy groups and clusters | Cosmology | 2023-06-29T20:10:30.000 |
| 4534 | 2013.1.00952.S | 6 | Spatially Resolved Mapping of Gas in a z=2.26 Normal UV-Bright Disk Galaxy | SDSS J0901+1814 (J0901; z=2.26) is a strongly-lensed UV-bright galaxy that we have detected in both CO(1-0) and CO(3-2). The clear velocity gradients in all images and our source-plane reconstruction show that J0901 is a rotating disk. We propose to make spatially-resolved observations of the CO(7-6) line (C34-2 configuration plus ACA observations), which when leveraged against our existing CO, optical, and infrared data will provide one of the most complete descriptions of a normal high-z disk galaxy to date. Specifically, with only 1.04 hours on the 12-m array (4.14 hours on the ACA) we will be able to (a) look for variations in the molecular gas excitation on sub-galactic scales, (b) explore excitation-related trends in the Schmidt-Kennicutt relation for a resolved high-z disk, and (c) find dark matter substructure in the lensing galaxy by identifying anomalous brightness ratios in the channel maps. In addition, we will obtain a high-resolution 1 mm continuum map useful for tracing star formation, and detect the [CI] fine structure line, which can provide an independent estimate of the system's gas mass. | Starburst galaxies, Gravitational lenses | Active galaxies | 2016-03-16T13:30:57.000 |
| 4535 | 2015.1.00442.S | 370 | Bright End of Number Counts Revealed by ALMA | We propose 1.1 mm (band 6) imaging of 336 bright submillimeter/millimeter galaxies (SMGs) detected in our AzTEC 1.1 mm surveys. In the previous studies of SMGs with single dish surveys, it is possible that multiple sources were counted as a "single" SMG due to the coarse angular resolution (~15-30"), which could produce "wrong" number counts. ALMA observations by Karim et al. showed that brighter SMGs split into multiple sources, and their counts are lower than previous results. However, that is the only interferometric study on the bright end number counts performed in one survey field. To resolve the discrepancy and the issue of cosmic variance, we will observe the largest number of SMGs in three different fields (AKARI Deep Field South, SXDS, and SSA22). We investigate the multiplicity of SMGs with a 0.5" resolution. Our ALMA observations allows us to make the most reliable number counts at bright end, and to constrain the flux range between the faint and bright end by filling the intermediate flux range which has not been probed accurately. (This is a resubmission of our proposal (2013.1.00781.S) approved as a highest priority in cycle 2.) | Sub-mm Galaxies (SMG) | Galaxy evolution | 2017-08-12T09:43:08.000 |
| 4536 | 2018.1.00922.S | 418 | Nature of Herschel-Selected Distant Starbursts (Time Filler) | Herschel has uncovered a population of extremely rare, bright, typically gravitationally lensed massive dusty starbursts, making them strongly-magnified versions of the most intense starbursts throughout cosmic times. Using short observing blocks as an ACA "time filler", we here propose to observe 29 high-J CO lines toward a sample of 15 Herschel-selected starbursts to complete their CO line ladders, also covering [CI], OH+, and high-level H2O lines "for free" (~60 lines total). This will enable us to study the excitation of the warm gas in the star-forming regions and the starburst nuclei of these intriguing systems, and to investigate if the physical conditions for star formation systematically differ from nearby starbursts. This comprehensive program will substantially improve our understanding of the physical properties of and diversity among the most intense starbursts throughout cosmic history, providing key constraints on their importance for early massive galaxy formation. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2019-12-20T22:25:27.000 |
| 4537 | 2017.1.01027.S | 1526 | Structural evolution and quenching in massive galaxies at z~2 | We propose 0.2arcsec-resolution and 1.0arcsec-resolution observations of 870 um dust continuum emission for a mass-selected sample of 101 massive star-forming galaxies at z~2 in the CANDELS/3D-HST fields. For all sources, the spatial distributions of stars and unobscured star formation are well studied by deep HST maps with <0.18arcsec-resolution. Investigating the spatial extent of dust-obscured star formation at comparable resolution, we will address the key question: "where stars form in massive galaxies at z=2". The synergy between the proposed ALMA survey and HST will provide a large, unbiased, homogeneous sample with multi-wavelength morphological information to determine how galaxies evolve through the planes which encapsulate structural evolution (M-SFR, M-n, and M-Re). This is not possible with the date in the archive because the sample is biased and the data quality (sensitivity and uv coverage) is insufficent to characterize the spatial extent of the dust emission. Our pilot survey and CASA simulations demonstrate that the proposed studies are feasible and highly efficient. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2019-09-22T10:03:17.000 |
| 4538 | 2019.1.01219.S | 900 | Confirming the Quiescent Nature of Massive Galaxies at z=4 | We propose 7.7 hr of ALMA Band 6 continuum observations for a sample of 100 candidate massive quiescent galaxies at z~4. Previous observations of the fraction of massive galaxies in this epoch which have stopped forming stars are widely discrepant, with some studies finding up to half of massive (log M/Msol > 11) galaxies are already quenched just a few Gyr after the Big Bang. This is in significant tension with models, which predict that essentially all massive galaxies should still be forming stars during this epoch. We have leveraged the new 20 deg^2 SHELA multi-wavelength survey to select a new sample of massive galaxies, robust against sample and cosmic variance. We measure a quiescent fraction amongst this sample of 13.7% (506 quiescent out of 3686 massive galaxies). However, our candidate quiescent galaxies have colors which are also consistent with obscured star-formation activity. In just a few minutes per source with ALMA, we can place stringent upper limits on the star-formation activity in these sources, ruling out all dusty star-forming solutions, allowing these results to place strong constraints on models of massive galaxy quenching in the early universe. | Galaxy structure & evolution | Galaxy evolution | 2021-04-21T21:30:48.000 |
| 4539 | 2016.1.01116.V | 0 | Understanding jet formation and testing the binary SMBH system in OJ287 | We propose 3 mm GMVA+ALMA observations of the BL Lac object OJ287, one of the best candidates for hosting a binary SMBH. The improvement in the north-south resolution and sensitivity provided by ALMA and the comparison with quasi-simultaneous, resolution-matched 1.3 cm RadioAstron images will allow us to perform Faraday rotation synthesis and opacity analysis with an angular resolution of 30-40 microarseconds, a ~10-fold improvement with respect to previous studies. This would allow determination of the spectral energy distribution in the jet and the three dimensional structure of the magnetic field to test the binary SMBH scenario and to study the jet formation at spatial scales not probed previously. In particular we plan to i) search for signatures of jet wobbling in a binary SMBH system; ii) search for a secondary VLBI core to confirm the binary SMBH model; iii) resolve the Faraday screen across the jet width to search for dynamically important helical magnetic fields; iv) determine the strength of the magnetic field and the location of jet transition from Poynting-flux to kinetic energy-dominance; v) study what is the distance scale for jet acceleration. | Spiral galaxies | Local Universe | 2018-10-20T16:14:52.000 |
| 4540 | 2015.1.01425.S | 35 | Lensing through Cosmic Time II: Mapping the Remaining Fronter Fields | In cycle 2, ALMA observed the first 3 Frontier Fields clusters in band 6. We propose to complete this project by mapping the remaining 3 clusters in similar detail, providing a uniform sample of >100 ALMA detected objects and individual and stacked submm constraints on 10,000s of targets in the field. The observations stand to provide a long-lasting legacy and seed many future studies of faint submm galaxies. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-06-02T18:36:31.000 |
| 4541 | 2023.1.01706.S | 0 | Spatially resolved deep submm follow-up of z > 6 low-luminosity quasars with approved JWST's stellar light observations | In this program, we will measure [CII] and FIR continuum emission of a sample of 8 low-luminosity quasars at z > 6. All of our sample will be observed by JWST to robustly measure the stellar light of their host galaxies. Combined with the stellar mass data, we will discuss the location of these quasars relative to the star-forming main sequence. Our high resoliution (0.3") observations will also provide a spatially resolved picture of specific star formation rate. These will tell if the quasar feedback (quenching) is in action particularly around the nucleus. As these quasars are likely to be hosted by lower mass galaxies, we can perform a fair comparison of the host galaxy properties with non-AGN normal galaxies (such as provided by ALPINE and REBELS programs studying at comparable cosmic times): we will identify the distinctive properties of quasar hosts, which is crucial to understand the triggering mechanism of quasar activity. Owing to the high resolution, we will also perform dynamical modelings of the host galaxies to obtain their dynamical masses. With these, we will test the usual assumption in z > 6 quasar studies, dynamical mass ~ stellar mass. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2025-06-12T15:54:30.000 |
| 4542 | 2015.1.01548.S | 210 | ALMA Imaging of Bright Cluster-Lensed SMGs Discovered by the Herschel Lensing Survey | To discover exceptionally bright cluster-lensed submillimeter galaxies (SMGs) like the Cosmic Eyelash, our team has been conducting a large Herschel survey of gravitationally lensed galaxies in the fields of massive galaxy clusters: The Herschel Lensing Survey (HLS) (PI: Egami). The HLS has obtained deep PACS (100/160 um) and SPIRE (250/350/500 um) images of 54 massive galaxy clusters as well as shallower (but nearly confusion-limited) SPIRE images of 527 clusters with a total observing time of ~420 hours. Now completed, the HLS has identified a number of exceptionally bright Herschel sources that are likely cluster-lensed SMGs at z>1. Here, we propose to obtain high-resolution (beam=0.2'') ALMA dust continuum images (at 1.3mm) of these bright cluster-lensed SMGs discovered by the HLS. ALMA high-resolution images are essential for, (1) identifying the lensing geometry, (2) examining the relation between the submillimeter source and the counterparts detected at shorter wavelengths, and (3) probing the physical properties of individual star-forming regions through the reconstruction of the source-plane image. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-07-15T23:41:36.000 |
| 4543 | 2016.1.00732.S | 56 | Ionized Jets or Hypercompact HII Regions? | One of the most conspicuous signposts of disk accretion in the low-mass case is the generation of highly collimated jets. These jets have also been observed, usually in cm wavelengths, toward high-mass young stellar objects (HMYSOs). They are characterized by a central radio source (CRS) coincident with the HMYSO and with a string of ionized lobes. The CRS has been traditionally interpreted as a collimated, ionized jet. However, recent ALMA results on G345.49+01.47 show that the kinematics of the ionized gas of the CRS -- probed using hydrogen recombination lines -- is more consistent with a hypercompact (HC), photoionized HII region rather than a fast jet. The question giving the title to this proposal therefore is open: what is the nature of the plasma traced by the CRSs in high-mass jets? Are they the ionized jet itself, or are they HC HII regions photoionized by the young star? We propose to settle this issue toward a sample of three luminous HMYSOs associated with jets by observing their H41 and H39alpha lines. These observations are crucial in order to either derive consistently the jet's feedback and to start studying how disk accretion circumvents the ionizing radiation. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2018-10-03T14:05:19.000 |
| 4544 | 2019.1.00080.S | 15 | A direct measurement of the black hole mass in a quasar at z=6 | We propose to make 0.02arcsec(120 pc)-resolution observations of the CO(13-12) emission line in a bright quasar at z = 6.00. - Our primary goal is to measure the black hole mass with a new approach developed by our previous observations in nearby galaxies. This will be the first direct measurement of a black hole mass in high-redshift quasars. - We wii compare the measurement with the previous estimates based on the empirical calibration using line widths of CIV emission and continuum luminosities at 1350 A. If a significantly smaller black hole mass or an even larger mass is obtained by the proposed observations, it would have a big impact on our understanding of the formation mechanism of SMBH in the early Universe. - We will also observe the [CII] emission line at 0.14arcsec(800 pc)-resolution to estimate the dynamical mass of the host galaxy. The combined observations of CO(13-12) and [CII] line will pioneer a new way to study the relation between dyncamical mass and black hole mass even at z=6-7. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2022-06-29T18:12:32.000 |
| 4545 | 2017.1.00126.S | 109 | The cold circumstellar envelopes of evolved stars in the Large Magellanic Cloud | Evolved stars are significant contributors to enrichment of the interstellar medium. Herschel observations suggest strongly the presence of cold dust around evolved stars in the LMC. We propose ALMA continuum and CO (3-2) emission line observations of the 5 brightest evolved stars detected with Herschel at 350 microns. The ALMA observations will: 1) confirm the Herschel dust detections, 2) determine the outflow velocity of the wind, and 3) potentially resolve extended structure. Continuum emission gives the dust mass and temperature, necessary for understanding the dust production history of the star. Resolving CO line emission allows us to characterise the differences in wind velocity between metal-poor stars, synonymous with the early Universe, and those at solar metallicity. Finally, if we resolve structure, it will be the first extragalatic detection of a circumstellar shell interacting with the ISM of a galaxy. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-10-10T14:38:41.000 |
| 4546 | 2015.1.00853.S | 8 | Out of Gas? Testing the Link Between Gas Depletion and Quenching in a Massive Quiescent Elliptical Progenitor at z~1.5 | We propose to measure the CO molecular gas reservoir of C21434, a massive, recently quenched galaxy at z~1.5 to understand the physical processes responsible for truncating star formation at the peak of galaxy assembly. The proposed observations represent the first constraint on the gas content of quiescent galaxies outside of the local Universe. This measured gas mass will provide a strong test of dynamically regulated star formation models, which seem to explain residual molecular gas in local elliptical galaxies. We will investigate whether the process of quenching removed or altered the gas reservoir of C21434 and assess the depletion time scale for its residual star-formation. Finally, we will compare the observed molecular gas content with a suite of cosmological zoom simulations to assess the role of multiple stellar and AGN feedback mechanisms in setting the molecular gas content and quenching in massive galaxies. | Galaxy structure & evolution | Galaxy evolution | 2017-03-14T18:13:07.000 |
| 4547 | 2018.1.01312.S | 11 | Strong or Weak Fields? The Multi-Scale Magnetic Field Structure in the closest and youngest Cluster--Forming Filament | Recent observations with Planck and other observatories have shown that the large-scale magnetic field in molecular clouds is well-ordered, and therefore the main agent shaping clouds on large scales. Star formation is thus regulated by magnetic fields until self-gravity takes over via ambipolar diffusion. This raises the question at which spatial scale magnetic support ceases to dominate. One examines this issue best in a study that covers all relevant spatial scales in a single molecular cloud, down to interferometer-probed dense cores of order 0.01pc. Interestingly, ALMA has already delivered rich data on many selected cores and young stars --- but not a single study systematically combines in a given region parsec-scale field studies from Planck, SOFIA, etc., with sub-parsec data on individual young stars from ALMA. Here we target Serpens South, the youngest nearby low-mass cluster-forming cloud, for a first such study. We will explore magnetic fields across spatial scales and evolutionary phases (i.e., from starless cores to young stars). Advanced analysis procedures involving custom-made MHD calculations will reveal when and where magnetic fields dominate cloud evolution. | Low-mass star formation | ISM and star formation | 2020-11-21T15:23:54.000 |
| 4548 | 2013.1.00582.S | 12 | A Census of the Molecular Gas and Star Formation within a Milky Way-like Spiral at z=1.5 | Strong lensing can increase the angular sizes of galaxies at high redshifts, enabling studies on significantly finer linear scales than typically possible. One spectacular case of such a system is the z=1.491 spiral galaxy MACSJ1149.5+2233A1, which is lensed into four distinct images having magnification factors ranging between 8 - 23. We propose for 3.8 hr of ALMA Band-4 observations to map each of the 4 lensed images of MACSJ1149.5+2233A1 in the CO (J=3->2) line and 800um (rest-frame) continuum, achieving a physical resolution of ~500pc (i.e., the size of giant HII regions and molecular cloud complexes), to obtain a census of the molecular gas and cold dust content for a Milky Way-like spiral galaxy at a time when the universe was only ~1/3 of its present age. The combination of these new ALMA data with deep HST and VLA data at 0.3" resolution, sensitive to the (un-)obscured star formation, will provide SFR/M_H2 estimates for ~20 individual complexes, leading to a detailed study of the resolved star formation law on ~500pc scales within a disk galaxy at z>1. This investigation undoubtedly has a significant potential for publicity. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2016-09-24T11:40:24.000 |
| 4549 | 2015.1.01037.S | 31 | Dust and gas disk masses in the benchmark cluster IC348 | Investigating the evolution of disk masses as a function of time is of critical importance to planet formation theory as it indicates the amount of raw material that is still available for planet building at any given time. Compact young stellar clusters are ideal targets for such studies as they provide large population of disks with relatively narrow age distributions. We propose an ALMA band-6 survey of all ~140 Class II disks in the benchmark cluster IC 348. This cluster has an IR disk fraction of 50% and an estimated age of 2-3 Myr, and thus is particularly useful to establish the distribution of disk masses at the time half the disk population has already dissipated. Our scientific objectives are 1) to construct the disk luminosity function of this benchmark cluster to allow direct comparisons to younger and older regions, and 2) to measure the gas content and the gas to dust mass ratios in 2-3 Myr old disks in order to constrain the time available for the formation of different types of planetary systems. | Disks around low-mass stars | Disks and planet formation | 2017-12-07T18:30:40.000 |
| 4550 | 2019.1.01022.S | 308 | Quantifying the cool gas reservoirs of a benchmark sample of radio AGN: CO(1-0) observations of the 2Jy sample | Observations of the cool gas are crucial for understanding the triggering of luminous AGN and the impact they have on their host galaxies. ALMA opens a new window on the cool ISM in AGN via sensitive observations of the CO emission lines. Here we propose to use the most compact configurations of ALMA to make deep CO(1-0) observations of a complete sample of 29 luminous radio AGN at low-to-intermediate redshifts (0.05 < z < 0.3) for which we have already obtained multi-wavelength data of unprecedented depth and completeness from X-ray to far-IR wavelengths. The observations will be used to: (a) quantify the molecular gas contents of the host galaxies and thereby estiablish whether the triggering mergers are gas-rich or gas-poor; (b) investigate the causes of the observed diversity in AGN properties for a given radio power; and (c) determine whether the feedback effect of radio jets directly influences the star formation efficiencies in the host galaxies. As well as filling a key gap in our understanding of how radio AGN tie in with the evolution of massive early-type galaxies, the observations will also provide an important low-z benchmark for high-z studies of cool gas in AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2021-02-28T11:24:43.000 |
| 4551 | 2012.1.00756.S | 1 | Mining and resolving a contiguous 1.5 arcmin^2 window in the SXDF-CANDELS-UDS at 1.1 mm with ALMA | We propose to conduct high resolution ($0''.5$) Band 6 (1.1 mm) continuum imaging of a filamentary structure traced by (1) faint 1.1 mm to submm continuum emission coherently seen in deeply confused AzTEC/ASTE and SPIRE/Herschel images, and (2) a chain of H$\alpha$ emitters (HAEs) at $z \sim 2.5$ associated with various types of star-forming galaxies with a star formation rate (SFR) of $\sim$ 100 $M_\odot$ yr$^{-1}$ or more. The chain of HAEs is newly discovered during a course of extensive narrow-band imaging surveys of H$\alpha$ and [OII] emitters using Subaru telescope in SXDF-CANDELS-UDS. Interestingly, this filament is connected to a bright submillimeter galaxy (AzTEC-ID25), recalling a growing massive giant galaxy accompanied with a cosmic filament or stream. An unbiased mining of dusty star-forming population will be made on a contiguous $105'' \times 50''$ or 1.5 arcmin$^2$ rectangular window, which is achieved by 19 point mosaic, to cover the filament, with a 5$\sigma$ sensitivity of 0.3 mJy ($L_{\rm IR} \sim 6 \times 10^{11} L_\odot$ SFR $\sim$120 $M_\odot$ yr$^{-1}$). The science goals with these data are as follows. (1) To resolve the faint 1.1 mm emission below the nominal detection threshold of point sources in the confusion-limited deep AzTEC/ASTE survey. Despite of their faintness, the observed faint filamentary structures are very coherent to another deeply confused submm image taken with SPIRE, but their nature is totally unexplored. ALMA will resolve them into faint point sources, and we will compare the sources with known galaxies selected by optical/NIR/MIR/radio observations. Is the observed diffuse 1.1 mm flux the sum of emission from known high-$z$ galaxy population such as HAEs red-IRAC and MIPS galaxies? Or can we find any new type of dusty star-forming galaxies (but much less luminous than SMGs), which is invisible at other wavelengths? ALMA in cycle 1 already has a superb potential to uncover a new type of dusty galaxies which does not coincide with the known population of high redshift galaxies. And, this field is the best to make such a survey because we already know that there exist faint mm-to-submm emission. (2) To unveil dust-obscured star formation in various types of known galaxies, including HAEs, [OII] emitters, MIPS/IRAC selected galaxies, a X-ray selected AGN host galaxy, Lyman break galaxies, and a K-band selected star-forming galaxy. SFRs of these galaxies will be measured based on the 1.1 mm fluxes, which is free from the dust extinction. (3) To address the impact of environment on the properties of star-forming galaxies at $\sim$4 kpc resolution. Key parameters of star-forming activities such as specific SFRs, as well as the sizes and morphologies seen in dust and stars, will be measured by the combination of ALMA and CANDELS. The derived properties will be compared with those of galaxies in different environment, i.e., general fields and the proto-clusters. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2015-10-30T17:15:14.000 |
| 4552 | 2024.1.01645.S | 0 | A measurement of [N/O] abundance at z=12.3: on the origin of ultra-luminous galaxies at cosmic dawn | Searches for the most distant galaxies with JWST have revealed ultra-luminous galaxy candidates above z>10, whose existence have been suggested to challenge galaxy formation models. Possible explanations could include accreting black holes, a top heavy IMF or globular cluster formation. Potentially the most important constraint to disentangle these scenarios is the presence of ionised Nitrogen lines, suggesting super-solar [N/O] abundance. These lines have been robustly detected with JWST/NIRSpec in GNz11 at z=10.6, and more tentatively in GHZ2/GLASS-z12 at z=12.3. We now have a unique opportunity with ALMA to robustly confirm the super-solar [N/O] abundance in GHZ2/GLASS-z12 by targeting the [NIII]57 line, which has shifted to a good visibility window in band 8 at z=12.3. In only 8 hours of band 8 time we show that we can put important constraints on [N/O] and showcase the ability of ALMA to characterise the z>10 galaxy population. We will combine [NIII]57 observations with rest-frame optical lines detected with MIRI, approved ALMA data on [OIII]88, [OIII]52, to measure [N/O] abundance, hardness of the radiation field, and electron density to reveal the nature of GHZ2/GLASS-z12. | Lyman Break Galaxies (LBG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 4553 | 2016.1.01208.S | 413 | Gas fraction and depletion time of massive main sequence galaxies at z=3-5 | The evolution of the gas fraction and gas depletion time beyond redshifts of z=3 is ill-constrained and controversial for massive (log(M_star) > 10.0) normal star-forming, i.e. main sequence (MS), galaxies. This redshift range (z>3) is important as the cosmic star formation rate density increases. In Cycle 2 we detected 45/72 of such photo-z selected galaxies with an average log(M_star)=10.7 in their 240GHz continuum - our proxy for cold gas mass. These z~3.2 objects follow the expected trends in gas fraction and depletion time if a universal, log-linear SFR-gas mass relation is coupled to the observed time evolution of MS galaxies, while trends with specific SFR start to emerge. This proposal completes our Cycle 2 and ongoing Cycle 3 efforts yielding a probable sample of ~150 detections. Utilizing a new near-IR selection technique to select the most massive MS galaxies, we request 5.5 hr to obtain the gas mass for 45 galaxies at the high stellar mass end with an average log(M_star)=11.0 at z=3-5 highly complementary to the Cycle 2 objects with an average log(M_star)=10.3. These proposed observations will provide robust constraints vital for current galaxy evolution models. | Galaxy structure & evolution | Galaxy evolution | 2018-04-10T21:01:44.000 |
| 4554 | 2019.A.00040.S | 8 | ALMA observations of an extreme stellar dimming | "Little dipper" stars are a recently discovered kind of variable main-sequence stars that exhibit small (~ a few %) dimming events, usually attributed to transiting exocomets in these systems. The most famous example of these objects is Boyajian's star, which underwent a series of deep and aperiodic transits that decreased its stellar flux by up to 20% in some cases. Mechanisms such as a large family of exocomets and planetary collisions have been proposed to explain its peculiar behavior. A few days ago, the brightness of the Solar-type star ASASSN-21qj decreased by ~90% with respect to its quiescent value. This is, by far, the most extreme dimming event ever reported, maybe the result of large collisions of planetesimals in the system. We propose to obtain deep Band 7 continuum observations of ASASSN-21qj to search for sub-mm excess that would indicate the presence of mm-sized dust grains released in such collisions. A non-detection would place tight constraints on some of the most extreme scenarios that could explain this dimming event. These would represent the most sensitive (sub)mm observations to date of this mysterious kind of objects. | Debris disks | Disks and planet formation | 2022-04-15T11:12:43.000 |
| 4555 | 2017.1.01583.S | 497 | The frontier of rocky planet formation: are low-mass stars super-efficient? | Planet formation is significantly more successful around low-mass stars than for Solar-type stars like our own. However, this could be the result of a truly greater efficiency of planet formation or stellar mass-dependent differences in planet survival after formation. We propose to test whether planet formation is fundamentally different for low-mass stars by observing them after planet formation has finished, using the brightness and detection frequency of their debris disks as a proxy for the success of planetesimal growth. We propose a deep and comprehensive survey of all 39 M-type members of the beta Pictoris moving group (BPMG). Using a detailed collisional population model benchmarked against Herschel surveys of nearby stars, we have made predictions for the BPMG M-dwarf population, providing a reference model and hypothesis to test. Based on this model we expect about 10 detections of new disks. If no detections are made, we will conclude that planet formation around low-mass stars is efficient because it is able to mop up all planetesimals. If many detections are made, the conclusion is that the disk masses around young stars may be much higher than currently believed. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2019-08-28T15:32:12.000 |
| 4556 | 2012.1.00334.S | 15 | Dissecting a colossus: confronting recent theory with a multi-merging HyLIRG | Recent Spitzer and Herschel results have highlighted the importance of Sub-Millimeter Galaxies (SMGs) for studies of galaxy formation and evolution: SMGs contribute significantly to the total star formation in the early universe. Amongst these SMGs, only a handful are hyperluminous infrared galaxies (HyLIRGs; > 10^13 solar luminosities in the IR). For a standard IMF, a HyLIRG hosts a staggering star formation rate of > 10,000 solar masses per year for a very short (Myrs) period. We have identified an ultra-rare system of two merging HyLIRGs at redshift 2.41: HATLAS J084933.4-021443, alias g09h124. This source is an excellent system to confront current theory and showcase ALMAs scientific capabilities. Here we request less than 4 hours of ALMA time to obtain resolved kinematics/dynamics of several lines including the CO ladder, water vapor emission lines, CI, OH+, HCN, HNC, HCO+ and plus associated dust continuum emission. Our principal goals include (a) determining resolved kinematics and physical conditions of both HyLIRGs; (b) measuring kinematic and luminosity based masses of the different gas components, thus constraining star formation scenarios; (c) constraining the radiation field and the presence of AGNs; (d) constraining the presence and mass of outflows and winds; (e) calibrating gas masses derived from different emission lines, and (f) comparing the observational results to the most recent hydrodynamic simulations of isolated and merging galaxies. This economical program is well suited for ALMA Cycle 1, and will produce immediate scientific results which will also be useful in designing our's, and other's, large Cycle 2 programs on SMGs. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2016-10-06T23:33:04.000 |
| 4557 | 2021.1.00013.S | 3 | Supermassive black hole mass measurement in the Superantennae | We propose ALMA ~0.06" (~70 pc)-resolution, millimeter 183 GHz (1.6 mm) H2O line observations of the Superantennae (IRAS 19254-7245), the merging gas/dust-rich galaxy at z ~ 0.06 which displays extremely luminous megamaser emission of the 183 GHz H2O line, originating from molecular gas illuminated by active galactic nucleus (AGN) radiation. Using the bright, high surface brightness 183 GHz H2O megamaser emission coming from the very center (<<1 kpc) of the galaxy nucleus, we aim to (1) constrain gas dynamics in the vicinity of a mass-accreting supermassive black hole (SMBH), at the almost-dust-extinction-free millimeter wavelength, with an order of magnitude better spatial resolution than available ALMA data and with minimum uncertainty of >kpc-distributed stellar potential modeling, (2) directly measure the central SMBH mass of the Superantennae for the first time, by penetrating through a high column density of obscuring material, and (3) test the widely proposed growing SMBH mass scenario in gas/dust-rich galaxy mergers. The high sensitivity and high spatial resolution of ALMA are crucial for the success of this experiment. | Merging and interacting galaxies, Galactic centres/nuclei | Galaxy evolution | 2023-02-04T07:19:47.000 |
| 4558 | 2012.1.00077.S | 3 | Merging IR-Luminous Galaxies -- Arp 220 and NGC 6240 | This is a resubmission of a highly ranked proposal from Cycle 0 which so far has had ~50% of the requested data. (No observing-unit-set has been completed and we have not seen any of the partial data.) Here, we propose to complete those observations in Band 7. The higher sentivity and resolution now available in Band 7 (0.2 arcsec) obviates the need for precious Band 9 time so we drop the previous request for Band 9. [We have submitted a request for withdrawal of the remaining Cycle 0 Band 9 observations.] As in the original Cylce 0 request, we propose imaging in Band 7 (HCN, CS, H26alpha and continuum) at 0.20'' resolution for the dense starburst regions of Arp 220 and NGC 6240. These unprecedented data will probe the distribution and dynamics of star forming gas and star formation activity in the dense disk structures to enable new theoretical understanding of the physics, dynamics, star formation activity and associated feedback in the most active and rapidly evolving galactic nuclei. | Merging and interacting galaxies | Galaxy evolution | 2016-09-14T20:32:30.000 |
| 4559 | 2012.1.00522.S | 1 | Ionized Winds in High-mass Star Forming Regions: Masering Effects in Hydrogen Radio Recombination Lines. | Maser emission of hydrogen radio recombination lines (RRLs) is rare in star forming regions. So far, MWC349A is the only object where these maser lines have unambiguously been detected. Since this emission is measured with very high signal-to-noise ratios, the emission centroid maps of the maser lines provide extremely detailed information about the kinematics of the ionized gas with positional errors of less than 5 milli-arcseconds. By using the SMA, we have recently detected a new RRL maser object toward one of the sources in the Monoceros R2 star cluster, the MonR2-IRS2 high-mass YSO. The RRLs at wavelengths <0.85mm show a clear amplification of the blue-shifted emission with respect to the red-shifted gas, indicating that these lines are masers. Unfortunately, the lack of high enough angular resolution in the SMA images prevents us from clearly establishing the morphology, physical structure and kinematics of the ionized gas in this source, and to determine the origin of the RRL masers. We propose to use the unprecedented angular resolution of ALMA Cycle 1, to image the H21a line (Band 9) in the C32-6 configuration. The H21a line is the best suited RRL for this study since it is linked to the amplification peak of the maser effect. The comparison of the ALMA images with non-LTE 3D radiative transfer modelling of the RRLs, not only will help us to understand the physics of the RRL maser phenomenon, but will also provide key information about the kinematics and physical structure of the ionized gas associated with the innermost regions in high-mass objects. | HII regions | ISM and star formation | 2016-10-08T11:18:59.000 |
| 4560 | 2021.2.00116.S | 28 | Ice and Gas: Novel insights into the cold chemistry of molecular cloud cores | During the epoch when molecular cloud cores collapse to form young protostars surrounded by circumstellar disks, many molecules arefrozen out as ices on the surfaces of dust grains. The fraction of volatile molecules on icy grains may play an important role in determining the eventual architectures and compositions of planetary systems. Still, many questions remain concerning the exact interplay between volatiles in ice and gas, for example: how dependent is the chemical composition on the initial dense cloud core environment and its subsequent evolution during collapse? To address these questions we propose to map a highly extincted region of the Chamaeleon star-forming cloud complex with the ACA in well-defined molecular tracers of physical conditions and the on-going chemical processes therein. Infrared ice maps will be obtained for this same region with the James Webb Space Telescope as part of the IceAge Early Release Science program in 2022. The coupling of the gas-phase ACA observations of low excitation lines with the deep solid-phase JWST data will provide novel insights into the interplay between gas and ice in cold dense regions of star formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-12-30T10:58:42.000 |
| 4561 | 2021.1.00793.S | 23 | Unveiling a Massive Node of the Cosmic Web at z=3 | Galaxies form and evolve within the diffuse filaments of the Cosmic Web. Direct imaging of these filaments has for long remained elusive leaving many questions open: How do galaxies get their gas? What is the morphology and kinematics of accreting gas and how does this affect the gas content and star formation activity of galaxies? A recent MUSE survey around a z=3 quasar has finally provided one of the first images of contiguous cosmic filaments on Mpc-scales converging into a node containing a large galaxy concentration and the only known close-separation triple AGN at high-z. Because highly-star-forming galaxies are typically dust-obscured, the MUSE data gives a partial view of the galaxy distribution within and around filaments. To overcome this limitation we propose ALMA dust-continuum and CO mosaic observations in order to: i) obtain a complete census of highly-star-forming and dust-obscured galaxies in the field, ii) measure and correlate the gas content of galaxies with the density and kinematics of filaments in order to understand how galaxies get their gas, iii) reveal the morphological and kinematical properties of the gas component of galaxies within the Cosmic Web node | Lyman Alpha Emitters/Blobs (LAE/LAB), Sub-mm Galaxies (SMG) | Galaxy evolution | 2023-06-28T00:00:00.000 |
| 4562 | 2018.1.00933.S | 65 | How significant is 'UV-dark' star formation in the EoR? | We propose to obtain deeper and higher-resolution 1.2mm dust continuum observations of the brightest z ~ 7 galaxies. These galaxies have extended clumpy/merger-driven morphologies in the rest-frame UV, and are prime candidates for further HST /WFC3 imaging and JWST NIRSpec integral-field spectroscopy observations. Physical offsets between the rest-frame UV and FIR emission have been found in many z > 5 galaxies, suggesting a complex geometry in these highly star-forming systems. Our proposed observations will provide a unique spatially resolved view of obscured/unobscured star-formation into the Epoch of Reionization, thus determining how significant UV-dark star-formation is in the brightest and most massive LBGs in this epoch. These results will 1) determine the importance of geometry on the IRX-beta relation at z ~ 7 and 2) determine the importance of dust obscuration in shaping the bright-end of the rest-frame UV luminosity function at high-redshifts. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-09-10T16:30:59.000 |
| 4563 | 2016.1.00359.S | 15 | Resolving Carbon Monoxide Emission In An Extremely Metal Poor Galaxy | Molecular gas is a crucial component of the interstellar medium (ISM) and key to understanding processes of star formation. While carbon monoxide (CO) is known as one of the best tracers of the molecular gas in spirals, there is no CO detection in extremely metal-poor galaxies that are below 10% Solar metallicity. This arises critical questions about the property of cold ISM and how star formation proceed in these galaxies: star formation may just take place in the atomic gas as suggested by some models. We propose to spatially resolve the CO J=2-1 emission at 7% Solar metallicity that has been recently detected by us with a single dish telescope. We will (1) characterize the properties of CO-emitting clouds including velocity dispersions and physical sizes; and (2) measure the CO-to-H2 conversion factor based on the dynamical mass and compare it to the dust-based one. These studies will not only give important constraints on the property of star-forming ISM to help understanding star formation in extremely metal poor galaxies but also offer significant local references for investigations of primordial galaxies in the early Universe. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2017-12-24T01:44:08.000 |
| 4564 | 2016.1.01101.S | 18 | 12CO(4-3) observation of FIR luminous LAB18 in SSA22 protocluster at z=3.1 | Recently we detected four submm continuum emissions from 100 kpc scale LAB18 with ALMA. The SFR surface density of four dust continuum emissions exceed threshold of galactic superwinds for high-z star-forming clumps, suggesting that large-scale gas outflows can come from the dust obscured star formation. We propose 12CO(4-3) observation of FIR luminous LAB18 in SSA22 protocluster at z=3.1. [1] Line detection from the dust continuum: To confirm possible existence of four dust continuum in LAB18 more strictly, we need a spectroscopically observation. Because no obvious single counterparts are found in HST image, only ALMA can reach this objective. This observation allows us to quantify the gas mass, gas surface density, SFE, and gas-to-dust ratio which are all key to a detailed understanding of dust obscured star formation in massive galaxy formation site of LAB18. [2] Gas dynamics in LAB18: we will search for evidence of large-scale gaseous structure. Star formation based models of the origin of LABs predict mechanical feedback from outflows. LAB18 is the most luminous LABs in our four ALMA LABs, providing a chance to search for the large-scale molecular gaseous contents. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2018-02-11T06:37:05.000 |
| 4565 | 2021.1.00280.L | 348 | CRISTAL: a survey of gas, dust and stars on kiloparsec scales in star-forming galaxies at z~4-5 | ALMA has revolutionized our ability to characterize the cold gas and dust in distant galaxies, enabling pathfinding studies on global scales matched by premier observatories at other wavelengths. With deep HST imaging and the imminent launch of JWST, we are entering an era where stars and warm gas are studied in detail on kiloparsec scales. In this context we propose to carry out the CRISTAL Large Program, making good on one of the key design goals of ALMA to study early galaxies in [CII] emission on highly resolved scales. CRISTAL targets 19 typical z ~ 4-5 galaxies at kiloparsec physical resolution spanning a factor of 30 in stellar mass, and will produce detailed kinematic and morphological maps of the cool gas in and surrounding these galaxies. CRISTAL will provide the next leap forward and a lasting legacy in high-redshift galaxy kinematics, galactic outflows and halos, and ISM properties. CRISTAL enables the next frontier of multiwavelength resolved galaxy studies, combining ALMA, HST, and imminently JWST observations to understand the detailed physics of galaxy formation, the baryon cycle, and the connections between gas, dust, stars, and star formation. | Galaxy structure & evolution | Galaxy evolution | 2023-05-10T15:25:10.000 |
| 4566 | 2011.0.00399.S | 0 | High Resolution Spatial-Kinematic Structures of the TW Hya Disk | Recent studies have suggested that the magnetized protoplanetary disks can have non-Keplerian kinematics. In order to examine the theoretical prediction, we propose to observe the spatial and kinematic structures of the protoplanetary disk of the bright nearby CTTS TW Hya. The proposed observations with extended configuration on optically thick $^{12}CO(3-2)$ transition line will delineate the motion of the disk surface which is most seriously influenced by the magnetic fields of the disk. We hope to obtain the most sensitive and detailed map available to date to help constrain the disk model and improve our understanding of disk kinematics in the context of planet formation. | Disks around low-mass stars | Disks and planet formation | 2014-01-04T00:00:00.000 |
| 4567 | 2019.1.01307.S | 20 | The first measurement of the gas-phase metallicity at z=6 | We propose to make deep [NII] 205 um and [OIII] 88 um line observations in a submillimeter bright galaxy (SMG) at z=6 for understanding the chemical evolution in the early Universe. This will be the first measurement of gas-phase metallicity for galaxies in the epoch of reionization. Exploting the ALMA data-set of CO, [NII] 205 um, [CII] 158 um and [OIII] 88 um lines, we have developed a new method to measure the gas-phase metallicity in SMGs at z=4. In this proposal, we will expand this approach to a z=6 galaxy. A comparison between the proposed measurements and the recent cosmological simulations would provide important information for understanding the pshycal processes responsible for metal enrichment. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2021-03-26T01:17:14.000 |
| 4568 | 2012.1.00619.S | 8 | Medium-size Kuiper belt objects: the key to accretion in the solar system | The apparently extreme variation in ice-rock ratios of the Kuiper belt objects defies a natural explanation, but is clearly a fossil signature of the accretional and collisional history of this population. We propose three alternative accertional histories for the outer solar system and show how measurements of a small subset of medium-sized Kuiper belt objects can distinguish these very different histories. A small dedicated ALMA program can make the first precise and consistent measurements of the densities of these medium-sized objects and allow us to unravel the mechanism of accretion in the solar system. | Solar system - Trans-Neptunian Objects (TNOs) | Solar system | 2016-01-14T15:04:37.000 |
| 4569 | 2016.1.00413.V | 0 | Imaging the Global Magnetic-Field Structure Near Sgr A*: 3-mm VLBI with GMVA + ALMA | The Galactic Center supermassive black hole, Sagittarius A (SgrA), is vastly underluminous, emitting nine orders of magnitude below its Eddington luminosity and providing an important prototype of the ubiquitous class of low luminosity galactic nuclei. At lambda = 3.5mm, the emission from SgrA occurs within 15 Schwarzschild radii of the black hole, although its origin is not yet understood. Our recent very-long-baseline interferometry (VLBI) observations using VLBA+LMT+GBT resulted in the detection of non-zero closure phases indicating asymmetric emission at 3.5mm. Here, we ask for dual-polarization GMVA+ALMA observations at lambda = 3.5mm. With these we will be able to study the properties of the accretion and outflow from SgrA with unprecedented angular resolution and sensitivity, on timescales from months to minutes, revealing the magnetic field structure and dynamics throughout the accretion flow on scales from thousands to tens of Schwarzschild radii. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2018-10-20T16:14:50.000 |
| 4570 | 2017.1.00939.S | 41 | Probing the processes of early planet formation in the disk around a young, isolated, planetary-mass object | OTS44 is one of only four free-floating planets known to have a disk and the only one detected in the mm regime. We have shown that it is the coolest and least massive known free-floating planet (~12 MJup) with a substantial disk that is actively accreting. We have obtained Cycle 3, Band 6 ALMA continuum data that show a clear unresolved detection of the source. We find that the disk dust mass is in the range 0.07-0.63 MEarth, which allowed us to conclude that the scaling relation between Mdust and M* found for higher mass central objects holds through the substellar domain down to planetary masses. However, the estimates of both, the mass of the disk, and the mass of the central object are subject to huge uncertainties and bold assumptions. With this proposal we aim to derive the dynamical mass of the central object (for the first time a model-independent mass estimate for such a low-mass object) by spectrally resolving the gas content of the disk (in Band 7); and directly test grain growth (vital ingredient for planet formation) and dust mean temperature, by obtaining the unresolved spectral index of the disk with new Band 9 data, supplementing the Band 6 and 7 datasets. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2019-02-22T21:44:41.000 |
| 4571 | 2022.1.00657.S | 14 | Turbulent Structure around the Very Low-Mass Class 0 Protostar IRAS 15398-3359 | A principal goal of this proposal is to reveal the velocity structure and the angular momentum distribution of the protostellar core of the very young low-mass Class 0 protostar IRAS 15398-3359 and characterize its turbulent eddies/elements. In this source, two past outflows have recently been identified in addition to the on-going outflow, whose directions are largely different from one another. Such a dramatic reorientation of the outflow is most likely caused by episodic accretion events of the turbulent gas elements with different angular momentum axes. To examine such complex structures of the protostellar core, we observe the H13CO+ and CO isotopologue lines in Band 3 and analyze them by using two kinds of autocorrelation functions (ACFs), from which we derive the coherent size of the spectrum feature and that of the velocity gradient. They are used to evaluate the size scale of the co-rotating fluid elements in the core. This observation is a novel attempt to study the turbulent structure of protostellar cores and will largely develop our understanding of its importance in the earliest stage of star formation. | Low-mass star formation, Astrochemistry | ISM and star formation | 2025-03-20T21:36:30.000 |
| 4572 | 2018.1.01503.S | 14 | Detection of a circumbinary disk around the high-mass protostar G 014.23-00.50 showing periodic flux variability | We propose continuum and CH3CN/SiO thermal line observations in band 3 to detect a circumbinary disk around the high-mass protostar (HMP) G 014.23-00.50, which has shown flaring flux variations with the period of 23.9 days (the shortest so far). The evolutionary sequence of HMPs is still under debate because the mass accretion rate onto the stellar surface, where is directly unreachable tiny area even with ALMA, is the most significant factor to define evolutionary tracks. To understand the accretion rate in such a tiny area, periodic flux variability observed mainly in CH3OH masers around HMPs is the most powerful probe in terms of its time-scales from a few tens to a few hundreds days, corresponding to the spatial scales of 0.1-1 au (e.g., under the condition of Keplerian rotation). The periodic flares in the target source G 014.23 might be explained by a variation of the dust temperature at the maser emitting region on a circumbinary disk. As the first step in series to challenge flux monitor observations with ALMA in the next cycle, here we would like to detect a compact and spatially resolved object with evidence of a binary, which could be interpreted as a circumbinary disk. | High-mass star formation | ISM and star formation | 2022-11-02T18:57:13.000 |
| 4573 | 2022.1.01482.S | 28 | Origin of the Hub-Filament System G33.92+0.11 | Protostellar clusters are often found at the center of Hub-Filament Systems (HFSs), prompting the possibility that filaments play a cruel role in transporting material to the hub to provide the fuel needed for cluster formation. We propose to measure the dust continuum polarization and the C18O (2-1) line toward a HFS G33.92+0.11 with ACA using band 6. Wang et al. (2020) performed systematic statistics on the interplay between the orientation of filaments, gravity, B-field, and velocity gradient, and found that G33.92+0.11 is indeed dominated by the converging accretion flows powered by the global gravity. However, their JCMT observations lack the resolution to resolve the B-field within filaments with a width of ~15 arcsec, and thus unable to detect the expected transition of the B-field morphology from the outside to the inside of the filaments. The proposed ACA observations with a resolution of 5.5" will resolve the filaments by ~3 independent beams, and hence offer a crucial test to the suggested scenario. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-10-27T07:51:54.000 |
| 4574 | 2018.A.00022.S | 13 | Extending the high-redshift frontier: Confirming [CII]158um and dust emission at z~7.5 | We propose to unambiguously confirm an exciting [CII]158um line candidate and potential dust detection at z~7.5, which would constitute the most distant observation of [CII] to-date and allow the study of the ISM well into the epoch of reionization. Our line candidate has a significance of 4.1 sigma and is located on the optical/UV source position with a redshift at the peak of our tight photometric redshift estimate. If confirmed, the [CII] luminosity and line width would furthermore be consistent with expectations based on previous high redshift detections. Our proposed observations would also allow us to confirm the presence of far-IR continuum emission from our source - currently seen at the ~3 sigma level. Because ALMA will be in its most compact configurations for the next observing blocks and our source will have good visibility, now is the ideal time to conduct these observations. Immediate confirmation of this candidate would allow for exciting follow up studies already in the next proposal cycle (e.g. other spectral line diagnostics and high resolution dynamical studies). However, a robust detection is essential before the investment of significant observing time. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2019-09-18T11:27:23.000 |
| 4575 | 2012.1.00542.S | 30 | Barnard 30: a pre- and proto-brown dwarfs nursery? | We propose to confirm the pre- and proto-brown dwarf nursery recently discovered in the dark cloud Barnard 30, within the Lambda Orionis Star Forming Region. A sample of very low mass star and brown dwarf (BD) candidates are located in this place, and have been classified as Class I or Class II objects using IRAC/Spitzer and excess at 24 microns (from MIPS/Spitzer). We mapped recently the area with LABOCA and SABOCA at 870 and 350 microns and we detected a group of very low-mass cold dust condensations (~0.012-0.07 Msun). The southern part of this region (the part closer to the O star lambda Ori) shows a group of submillimeter sources associated with the coldest Spitzer sources (at 70 and 24 microns), suggesting they are very young. In addition, there are several very low-mass submillimeter detections with no MIPS/IRAC counterparts, which are excellent candidates to pre-BD cores. We propose to observe these pre- and proto-BD candidates with ALMA in continuum in band 7, in order to characterize their dusty envelopes, the stage of its evolution, and their gravitational stage at scales of 400 AUs. If we find pre- and proto-BDs surrounded by substantial envelopes and disks, similar to the ones observed in the first stages of low-mass protostars, they would provide direct support for in situ formation of BDs. Therefore, this proposal, requesting only 2.3 hr time, will impact in the different proposed scenarios concerning the formation of brown dwarfs. Previous efforts to characterize the formation of BDs have been performed in individual objects, but this would be the first time these studies are done in a whole region. | Low-mass star formation | ISM and star formation | 2015-04-30T00:00:00.000 |
| 4576 | 2018.1.01691.S | 198 | G267: testing the physics of star-forming filaments | Filaments are structures that assemble within the molecular clouds and are the preferential sites to find dense young clumps and cores. Although they seem to be an important phase in the whole star formation process, the question if the properties of young forming stars are related or influenced by the properties of the hosting filament is still open. Part of the reason is our largely insufficient knowledge of the physics of filaments, their interaction with the surrounding environment and with the hosted cores during their evolution. This proposal is intended to contribute with the complete characterization of the physics and kinematics of a nearby large-scale rectilinear and isolated filament with active star formation in different mass and stages of evolution. With complete ACA band 3 mapping of lines and continuum of this scaled-up version in mass and size of the Taurus filament, we will measure how the filament accretes from its surrounding, the rate of material transport along its spine and its relation to the position, properties and evolutionary stages of hosted dense clumps, and determine how these parameters compare to well-studied filaments of lower mass. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-01-20T15:54:28.000 |
| 4577 | 2012.1.00285.S | 4 | Exploring the Evolution of Molecular Clouds by the Velocity Vectors in NGC1566 | We propose to observe grand design nearby spiral galaxy NGC 1566 (at distance of 11 Mpc) in CO (1-0) with high resolution (106pc) enough to resolve GMA and without missing flux of extended gas. Giant Molecular Clouds (GMCs, size; 50pc) and Giant Molecular Associations (GMAs, size; 500pc) are origins of massive stars. Recent observations suggest that the evolution of the GMCs and the GMAs is greatly influenced by the galactic dynamics on arms (e.g., shear and galactic shock). The shear may destruct the GMAs into the GMCs and the galactic shock trigger star-formation. These dynamics are described by the velocity vectors of molecular gas. However it is difficult to observe the velocity vectors directly because we can know only the line-of-sight velocity of the galaxies. We invented a powerful method (KN method) to derive the velocity vectors of face-on spiral galaxies from the line of sight velocities of CO. We applied the KN method for M51 and NGC 4321 for deriving shear. It is indicated that only strong shear destructs the GMAs. However the resolution and the sensitivity of these data are not enough for discussion about the dynamical evolution of GMCs and GMAs in detail. NGC 1566 (Decl.=-55d) is good target for ALMA. Our observations reveal the effect of the galactic dynamics on the formation/destruction of GMCs and GMAs and the efficiency of star-formation. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2015-07-02T13:58:19.000 |
| 4578 | 2019.1.01056.S | 89 | Looking for the missing mass in Luminous Blue Variables | Massive stars play a fundamental role in the evolution of galaxies. they are among the major contributors to the interstellar UV radiation and provide processed material and mechanical energy to the ISM via their strong winds.Evolutionary models fail to reproduce the transition between their O and WR phases, mostly because of the poor knowledge of the amount of mass lost during the transition. recent work on three LBVs has shown that a so far neglected component of molecular gas is present around these stars. On the basis, of the three previous detections and our APEX data, we propose to observe 9 Galactic LBVs with the ACA in the 12CO and 13CO J=2-1 lines. The immediate goal of our project is to detect the CO emission and estimate the associated nebular mass as well as a first kinematic analysis of the molecular gas. The proposed observations will complement the Herschel data (PACS and SPIRE) of these source available from the Hi-Gal and MESS projects. | Luminous Blue Variables (LBV) | Stars and stellar evolution | 2020-11-29T00:00:00.000 |
| 4579 | 2021.1.00727.S | 18 | Ortho-H2D+ in the cores close to the onset of star formation | We propose to observe the ortho-H2D+ 1(1,0)--1(1,1) line at 372.42 GHz from two starless cores and one protostellar core in the Orion molecular complex. Two starless cores, G208.68-19.20-N2 and G209.19-19.65-S1, are considered to be evolved prestellar cores on the verge of star formation, because of their high [D]/[H] ratio of ~0.2 and high H2 volume density of ~10^7 cm-3. The protostellar core, G204.4-11.3-NE, harbors a source with very-low luminosity (0.027 L_sun) and low bolometric temperature (57 K).The deuterated molecules such as N2D+ and DNC are also abundant in this core, suggesting that this core is just after the onset of star formation. The ortho-H2D+ observations with the ACA allow us to study the spatial distribution of the ortho-H2D+ line at a resolution of 1500 au. We are able to study the variation of the orho-H2D+ abundance as a function of evolutionary stage. The orho-H2D+ emission line also allows us to study the kinematics of dense and cold region in which most of the molecules are depleted onto dust grains. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2022-12-02T10:23:46.000 |
| 4580 | 2017.1.00221.S | 18 | Resolving HCO+ in the ejecta of Supernova 1987A: effect of mixing | From our ALMA Cycle-2 and Cycle-3 spectral line scan program, we discovered HCO+ in the ejecta of supernova (SN) 1987A. The estimated HCO+ mass was about 12 orders of magnitude larger than predicted by chemical models. In order to determine where and how HCO+ was formed, we propose a high-angular resolution imaging of HCO+. The classical image of the stellar interior of the progenitor star is onion-layers of different nuclear burning zones. If a SN sustained this geometrical structure after the explosion, little HCO+ can form --- H atoms are in the H-envelope, while most C and O atoms are located in the He envelope and C + O nuclear burning zones. The likely way to form HCO+ is that microscopic and macroscopic mixings stirred elements from different nuclear burning zones immediately after the SN explosion. We expect that HCO+ will be found in clumps formed by macroscopic mixing, and that microscopic mixing diffused elements from different nuclear burning zones. HCO+ clumps should be located at more extended than CO and SiO, but more compact than Halpha. The distribution of HCO+ can provide important insight into the hydrodynamics and chemical processes of the supernova explosion. | Supernovae (SN) ejecta | Stars and stellar evolution | 2020-01-23T21:32:05.000 |
| 4581 | 2017.1.01391.S | 76 | Dust and synchrotron emission in SNR 0540-69.3 | We propose to observe the supernova (SN) remnant (SNR) 0540-69.3 in the ALMA Bands 4, 6 and 9 to establish the synchrotron spectrum of the pulsar-wind nebula (PWN) surrounding the pulsar (PSR) B0540-69.3, and to constrain the mass of cold dust in the PWN. For the synchrotron emission, the data will be combined with radio data and data at higher frequencies to probe the energy loss of relativistic particles in the PWN. Currently, nearly all models are based on the Crab PWN. A second target is crucial to constrain the models. SNR 0540-69.3 is the next logical step. With the spectral base fixed from the power-law synchrotron continuum in Bands 4 and 6, Band 9 will be used, in conjunction with Herschel PACS data that show emission from the PWN region of SNR 0540-69.3 at 100 and 160 microns, to measure the mass of cold dust. The discovery of >0.2 solar masses of cold dust in SN 1987A, and large amounts of dust also in Cas A and the Crab, indicates that core-collapse supernovae (SNCC) may be important dust contributors, which could explain the early appearance of dust in the Universe. If cold dust exists in large quantities also in SNR 0540-69.3 dust could be present in most SNCC. | Supernovae (SN) ejecta | Stars and stellar evolution | 2019-03-30T22:46:13.000 |
| 4582 | 2013.1.00556.S | 0 | Structure and properties of the molecular gas in LMC-N11B | We propose to map 12CO(1-0) in the star-forming region N11B in the Large Magellanic Cloud. N11B is a unique case of multiple sequential star formation in a nearby metal-poor system. We aim to examine the structure of the molecular gas with ALMA and to use the synergy with Herschel to solve the long-standing paradigm of photodissociation regions in low-metallicity environments. There is growing evidence that CO traces a small filling factor (<10%) of the interstellar medium (ISM) in the form of small clumps. On the other hand, the photodissociated envelopes can harbor a significant fraction of the molecular gas H2 - necessary to fuel star formation - accountable via FIR cooling lines such as [CII] 158um. Our objectives are to: - identify the CO clumps, study their size and mass distribution as a function of the environment (e.g., feedback from the massive star clusters and the impact on the propagation of star formation under extremely porous ISM conditions). - examine the [CII]/CO(1-0) ratio and construct a PDR model. We will quantify the mass of CO-dark molecular gas and shed new light on the metallicity dependence of the conversion factor between CO and H2. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2017-01-20T18:42:48.000 |
| 4583 | 2013.1.00788.S | 3 | Measuring Crucial Parameters of the First Known Stellar Merger | Nova Sco 2008 was recently identified as the first definite merger known between two convective stars. Stellar mergers are thought to be a significant factor in the evolution of stellar clusters and galactic centers, as well as possibly the origin of several types of unusual stars, but they are poorly understood because of a lack of data until now. One critical parameter for both dynamical modeling of the merger and predictions of the nature of the merger remnant is the amount of mass expelled from the merger during the outburst. Infared data of the merger remnant show that there is a substantial amount of dust in the ejecta. We propose to estimate and constrain the mass of the dust using standard techniques of millimeter astronomy. Our measurements will also constrain the nature of the dust, and form an essential component to modeling the ejecta material for the first time. | Evolved stars - Shaping/physical structure, Cataclysmic stars | Stars and stellar evolution | 2016-08-26T17:06:49.000 |
| 4584 | 2019.1.01245.S | 0 | Density measurement of solar spicules by a Hydrogen recombination line | Our aim is to derive electron density in solar spicules with a high accuracy of less than 100% to estimate accurate energy flux transported toward the solar corona. We propose a density measurement by H26alpha at 353.6 GHz. The line width of H26alpha is dominated by the Stark broadening, and the typical width will be 1.5 GHz (FWHM) when N_e ~ 10^10 /cm. We propose two observations for ALMA cycle 7. One is an 11-point MOSAIC observation across the limb to revisit and confirm the density structure of the chromospehre, and the other is a fixed-pointing observation at the limb to investigate the density evolution of the dynamic spicules. When we assume the noise level of the brighteness temperature of 10 K, uncertainty of density will be within 60% at the typical formation layers of hydrogen recombination lines. This accuracy is unprecedented for spicule observations, and will provide the information of an accurate energy flux transferred into the corona. | The Sun | Sun | 2021-12-18T08:51:26.000 |
| 4585 | 2024.1.00025.S | 0 | Studying CO SLEDs of local LIRGs at 100 pc resolution | This program targets 12m+ACA observations of the CO (4-3), (6-5), (7-6), and (8-7) molecular gas line emission and continuum emission in bands 8 to 10, of a sample of 6 U/LIRGs. The main purpose of these observations is to recover and map the distribution of the warm gas at mid J transitions of these galaxies for the first time at ~ 100 pc resolution, a factor of ~60 improvement in resolution compared to existing Herschel observations. We will reveal for the first time the morphology of the highest excitation CO gas that can be accessed from the ground, and along with matched resolution lower J CO archival observations will provide the highest resolution low to mid-J CO SLED in local U/LIRGs. Modeling such SLEDs will provide accurate estimates of the density and temperature of the gas and overall mass distribution at 100 pc scales. These galaxies all have archival or approved JWST observations of mid-infrared vibrational molecular gas lines (H2), which will allow us to perform a multiphase census of the interstellar medium in local U/LIRGs at an unprecedented spatial resolution unachievable with previous IR observatories. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 4586 | 2016.1.01430.S | 52 | Proper Motions of Gas in the Immediate Vicinity of the Galactic Supermassive Black Hole | In our Cycle 2 experiment, we discovered a very compact (<0.2") high velocity (-450km/s) emission and absorption component in HCN(4-3), exactly centered on the Galactic Center SMBH SgrA*. This component is barely resolved at 0.2" beam and shows significant variations during 4 separate epochs spanning 2 months. In particular, a narrow absorption feature is seen to shift in velocity by about 25 km/s during this period. The motion is consistent with a neutral dense cloud orbiting SgrA*, and could be associated with the G2 cloud infalling towards SgrA*. Because of its high velocity and faint intensity, this feature has never been seen before. In this cycle, we request 4 further epochs of observations to be separated on the order of 2 months again to trace the dynamics. We request higher resolution of 0.034" to resolve the emission structure to test whether this is a gas streamer elongated in the direction of the detected velocity gradient. This study is making use of SgrA* to provide a very narrow pencil beam to study absorption and structural changes on very short time scales. We also make use of the high excitation submm lines in order to sample the neutral gas closest to SgrA*. | Galactic centres/nuclei | Active galaxies | 2019-10-12T17:06:33.000 |
| 4587 | 2016.1.00123.S | 32 | ALMA's First Look at the Crab Pulsar | Since its discovery in 1968, the Crab pulsar (B0531+21) has been heavily studied in almost every wavelength band from the radio through to the high-energy gamma ray. One of the last remaining gaps in the SED falls in the mm/sub-mm regime; here we propose to fill this gap using ALMA. Specifically, we seek to obtain continuum observations of the phase-averaged (i.e., not resolving the pulse in time) emission at 97.5 GHz (Band 3), 340 GHz (Band 7), and 665 GHz (Band 9). These observations will build an important bridge between the declining flux densities (with frequency) at radio wavelengths and the increasing flux densities at infrared wavelengths. The spectral "turnover" that must exist at intermediate wavelengths, which we will probe with the proposed observations, corresponds to a transition between coherent and incoherent emission mechanisms. Under certain assumptions regarding the underlying theory, the wavelength at which this turnover occurs can constrain the separations between particles in the parcels of plasma producing the emission. We request observations in three different ALMA bands to ensure that we can constrain the location of this turnover in the SED. | Pulsars and neutron stars | Stars and stellar evolution | 2018-11-13T20:38:12.000 |
| 4588 | 2016.1.01326.S | 64 | Unifying Stars and Gas in Quasar Hosts at z~3 and the Co-Evolution Picture | The physical mechanism of the black hole-host galaxy co-evolution is one of the most important questions in astrophysics. We propose to observe a unique sample of quasars at z ~ 3, the peak epoch of the active galactic nucleus accretion history. Their host galaxies differ by about 1 dex in their stellar masses (M*) compared to the black hole (BH) mass and show significantly different narrow-line region properties traced by their OIII luminosity. These quasars are drawn from 70 quasars whose hosts are studied with Subaru AO-assisted imaging. We detected stellar components for two and estimated upper limits for the other two targets proposed here. Since their BHs are well assembled and massive, these systems can serve as a testbed for the co-evolution mechanism. We will test whether a larger amount of gas is present in the more evolved hosts and hence the expected extreme CO luminosities that will allow spatially and dynamically resolved CO line observations similar to our Cycle 3 program. Together with our M* estimates/limit, we will use the gas and dynamical mass estimates to trace their past and possible future evolution onto the well established local BH-host scaling relations. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2018-04-12T00:06:15.000 |
| 4589 | 2016.2.00134.S | 17 | The Molecular Gas Content in the NGC 5044 Group | The NGC 5044 group is the best candidate for studying star formation in an AGN-perturbed cooling flow due to its proximity and extensive multi-frequency coverage. Our ALMA cycle 0 observation of N5044 in CO(2-1) detected 24 molecular structures. Based on the molecular masses and CO linewidths, these structures are probably giant molecular associations and not individual GMCs. In cycle 4, we successfully proposed for higher spatial resolution observations with the primary goal of resolving these structures into individual GMCs and obtaining the first statistical sample of GMCs that condensed out of a cooling flow. While our previous ALMA observations have been very informative regarding the properties of compact molecular structures in cooling flows, the majority of the molecular gas (~70%), as measured by an IRAM 30m obervation, remains unaccounted for in the ALMA 12m array data. We therefore propose for a 7m array observation in CO(2-1) to probe the more extended and diffuse component of molecular gas. The distribution and kinematics of this dominant molecular component is essential for a full understanding of the formation of molecular gas in cooling flows. | Early-type galaxies, Galaxy groups and clusters | Galaxy evolution | 2018-08-02T23:50:06.000 |
| 4590 | 2017.1.00759.S | 178 | Probing the onset of feedback - vibrationally excited HCN in pre-outflow ULIRGs | Studying the accretion and growth of supermassive black holes (SMBHs) and their surrounding stellar components is essential for our understanding of how they evolve with their host galaxies. Interacting Luminous and ultraluminous infrared galaxies U/LIRGs are strongly linked to nuclear growth since they funnel massive amounts of gas and dust to their nuclei. Massive molecular outflows powered by the activity are invoked as mechanisms for regulating the nuclear growth. To study the most embedded activity and the onset of feedback, we must probe behind the curtains of dust with a line that is uniquely tracing extreme nuclear conditions. We propose a survey of the 1mm transition of vibrationally excited HCN (HCN-VIB) in a sample of merging ULIRGs. We aim to investigate tentative evidence that the HCN-VIB line emission is anti-correlated with outflow velocity - suggesting that HCN-VIB luminous nuclei are in an extremely transient pre-outflow phase of the ULIRG evolution. We will use the simultaneous observations of the ground state HCN and HCO+ lines to obtain the structure and dynamics of the central gas disk, and to search for very dense outflows inside the obscuring dust. | Outflows, jets, feedback | Active galaxies | 2019-10-09T05:16:27.000 |
| 4591 | 2019.1.01781.S | 43 | Search for Self-Gravitating Cores in the Cloud-Cloud Collision Region CO-0.4 | Cloud-cloud collision (CCC) is a promising mechanism of efficient formation of high-mass stars/clusters in the central molecular zone of the Milky Way, where high CCC frequency is expected as a consequence of extreme concentration of dense gas. CO-0.4 is a newly-discovered candidate site of an on-going CCC event; ALMA observations have revealed two distinct velocity components bridged by broad emissions of SiO 5-4 line, which is a classical signpost of CCC. We have also discovered a few bright peaks of DCN or COM species in the midst of the fast turbulence in the CCC interface; preliminary analysis shows that several of them may have very high density (10^7 cm-3), relatively narrow velocity width (2 km/s), and possibly a low virial parameter of 1-10. For cycle-7, we propose a follow-up observation to measure accurate values of their masses, virial parameters, and volume density distribution on the basis of excitation analysis with multi-transition CS, SiO, and HCN lines. If these peaks are confirmed to be self-gravitating cores that are capable of star-formation, we may be able to firstly capture the onset of CCC-triggered star-formation in the Galactic central region. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2021-06-30T01:46:18.000 |
| 4592 | 2012.1.00900.S | 4 | Winds of change II - imaging the extremely young outflow of the FIR-excess galaxy NGC1377 | We propose high resolution 0."16 (13 pc) Band 7 ALMA CO 3-2 and continuum observations of the dusty, young molecular wind and core of the extreme FIR excess galaxy NGC1377. The extreme spatial resolution and sensitivity offered by ALMA and the proximity of NGC1377 allow us to image the morphology and velocity structure of the outflow down to the very nucleus of the galaxy. The acceleration, mass outflow rate and wind driving mechanism can be addressed as well as the nature of the dust obscured nuclear power source. We also propose Band 9 CO 6-5 and continuum observations to address the physcial conditions of the nuclear gas, search for a Compton thick nucleus, constrain the continuum luminosity density of the nucleus testing the notion of a buried AGN. Resolving the outflow of NGC1377 will help us understand how galactic winds are triggered, how they evolve and the role they play in the overall evolution of galaxies. Mounting evidence suggest that molecular outflows may be common in AGNs and starburst galaxies where they regulate star formation and growth of supermassive black holes. | Outflows, jets, feedback, Galactic centres/nuclei | Active galaxies | 2015-09-09T12:18:39.000 |
| 4593 | 2023.1.00467.S | 0 | What is the trigger of the chemical diversity around massive young stellar objects? | The chemical composition around massive young stellar objects (MYSOs) is a key towards understanding the initial conditions and formation processes of massive stars. Recent observations show a possibility of chemical diversity around MYSOs; complex organic molecule (COM)-rich hot cores vs. carbon-chain-rich MYSOs. Such a chemical diversity should reflect the variety in formation processes and the influence of the environment, but it is still unclear which factors are the most important. We propose observations of cyanopolyynes (HC3N and HC5N) and COMs in Band 3 toward the MYSO G28.28-0.36. This MYSO is likely to present unique chemical features; carbon-chain species are abundant but COMs are deficient, making this target especially suitable for the investigation of the origin of the chemical diversity. We will derive the spatial distributions of cyanopolyynes and COMs as well as their abundances to confirm the unique chemical feature of this MYSO. We will also evaluate possible factors that may produce such a unique chemical feature, comparing the observations with the results of chemical simulations. | Astrochemistry | ISM and star formation | 2025-01-30T01:25:29.000 |
| 4594 | 2023.A.00018.T | 29 | Constraining Black Hole Jet Formation with ALMA and JWST | Relativistic jets launched by accreting black holes can affect star formation, galaxy evolution and even the distribution of matter in the Universe. Therefore, it is essential that we understand the process of accretion and the physics of these accretion-fed outflows. Black hole X-ray binaries (BHXBs) provide ideal laboratories for probing jet phenomena. In particular, broadband spectral measurements of jet emission in BHXBs during bright outburst periods allow us to constrain the physical conditions in the jet, which can then be coupled to the properties of the accretion flow, probing the mechanisms that govern how jets are launched and quenched. The mm/sub-mm regime bridges a crucial gap between radio and IR frequencies, as data in this regime are essential when performing detailed spectral modelling. We propose targeting the currently outbursting BHXB GX 339-4 with multi-band ALMA DDT observations, to accurately measure the mm/sub-mm flux. These ALMA data will be coupled with our exceptional multi-wavelength coverage (spearheaded by JWST), to constrain the broad-band spectral energy distribution in BHXBs with unparalleled accuracy. | Black holes, Transients | Stars and stellar evolution | 2024-09-18T18:55:13.000 |
| 4595 | 2011.0.00121.S | 0 | Search for Submillimeter H2O Maser Towards Active Galactic Nuclei | We propose to search for submillimeter H2O masers towards active galactic nuclei (AGN). Galaxies in our sample are listed from known 22 GHz "disk" masers showing the presence of a sub-parsec scale disk or characteristic spectra. These sample galaxies show the strongest flux density of the 22 GHz H2O maser among about 150 H2O extragalactic masers known to date. Our primary aim of this program is 1) to study distribution of temperature and density in sub-parsec scale regions of AGN by detecting different transitions of submillimeter (submm) H2O masers at 22 GHz, 183 GHz, 321 GHz, and 325 GHz. First of all, we need to detect the 321/325 GHz transition in this Cycle 0 program. Since the pumping mechanism of these transitions is similar, we might be able to discover the new submm H2O maser in the largely same region and in the same galaxies as the 22 GHz maser exists, or new masers could be potentially detected in unexplored region of AGN, 2) by monitoring the line of sight velocity of the maser, we aim to detect systemic accelerations, assuming the submm maser lying on a rotating disk. Also, we aim the first detection of the accelerations of the maser on the back side of the disk. We have more chance to detect it since submm continuum emission obscuring the maser on the back side could become optically thin. This will confirm the generally accepted rotation disk model, and 3) to provide the line intensity ratio between the transitions, which will be critical for developing the numerical simulation, based on radiative transfer model. | Active Galactic Nuclei (AGN)/Quasars (QSO), Spiral galaxies | Active galaxies | 2013-08-21T08:18:00.000 |
| 4596 | 2024.1.01401.S | 0 | A survey of dust and metals in typical star-forming galaxies at z~4-6 with multi-band ALMA and JWST observations | Characterizing the properties of dust and metals in typical star-forming galaxies at z>4 is crucial for understanding the physical mechanisms driving galaxy formation and evolution. However, our current knowledge of the properties in these galaxies is largely incomplete as a result of inadequately sampled observations of the dust spectral energy distribution (SED). For this reason, key dust properties such as dust temperature, mass, infrared luminosity, and obscured star formation activity remain poorly constrained. To lead the way forward, comprehensive multi-band ALMA observations are necessary to adequately sample the dust SED. The objective of this proposal is to obtain such observations for a sample of 7 star-forming galaxies at z~4-6 which will very soon have complementary JWST/NIRSpec observations of the main nebular lines. Our ALMA observations are designed such that we are maximizing the sampling of the dust SED thanks to existing data on the ALMA archive. Our proposed observations will produce a survey of dust and metals in normal galaxies at high-z that will become a benchmark for future observational and theoretical studies of the dust and metals in the early Universe | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 4597 | 2012.1.00175.S | 17 | Physical conditions in high-z galaxies from water vapour emission and the origin of molecular outflows | It has recently been established that luminous water vapour lines probe the local infrared (IR) radiation field in galactic nuclei. This is a unique diagnostic, totally different from commonly observed molecules such as CO. Herschel results show that all Ultraluminous Infrared Galaxies (ULIRGs) emit luminous high-excitation H2O lines, originating in extended (several 100 pc), highly obscured (opaque at 100 micron) regions of warm and dusty molecular gas. High local infrared radiation pressures are derived, and these may be related to the occurence of molecular outflows that turn ULIRGs and QSOs into passive galaxies. H2O lines are unique in selecting such regions, and in determining their properties (dust temperature, infrared opacity, column density, mass). We propose an ALMA Cycle 1 study to fully exploit this diagnostic in 2 gravitationally lensed high-z galaxies: the Cloverleaf, harbouring a QSO nucleus, and the Eyelash, which is powered by star formation. We will observe the minimum set of H2O lines required to establish the H2O excitation, the local IR field and IR radiation pressure. Simultaneously, we will observe OH+ lines, looking for P-Cygni profiles indicating molecular outflows. Observing at 0.2" resolution we will spatially resolve the lensed images, reaching a source plane resolution comparable to Galactic giant molecular clouds, pinpointing the origin of the H2O emission and the outflowing gas and establishing their relation, and the relation to the underlying continuum. This project will pave the way for future ALMA observations of H2O emission in high-z galaxies, probing directly the highly obscured nuclear regions and the dynamical and radiative feedback processes arising there. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2016-10-31T13:02:48.000 |
| 4598 | 2016.1.00158.S | 5 | Chemistry in the terrestrial planet-forming zone: a unique view with ALMA HCN | Studies of the inner few au of disks - the terrestrial planet forming zone and the realm of the bulk of the detected Jovian exoplanets - have so far been limited to infrared observations. The IR data only probe the surface layers of disks; ALMA provides the first opportunity to probe deeper and closer to the midplane. We propose here a pilot project to use the HCN vibrationally excited J=4-3 line to probe the physics and chemistry of the inner disk with ALMA for the first time. Due to high temperatures and ice evaporation, abundances are predicted to be orders of magnitude higher in the inner few au, and the vibrationally excited HCN lines have excitation requirements that are beautifully matched to the inner disk physical conditions yet greatly lessen the impact of dust opacity. Combined with HCN v=0 data of the outer disk obtained in the same setting, our data will allow radial and vertical abundance profiles to be retrieved and assess the gas-phase nitrogen budget. These data are also an important complement to upcoming JWST-MIRI GTO observations. | Disks around low-mass stars | Disks and planet formation | 2018-09-05T16:07:12.000 |
| 4599 | 2018.1.00756.S | 473 | A comprehensive survey to study the evolution of high-density cores in Taurus | We propose to make an comprehensive survey of dense cores in the nearby Taurus molecular cloud with the ACA standalone mode. The aim is to investigate the core evolution at the early collapsing phases. Evolution of low-mass pre-stellar core is characterized by the radial density profile. Despite the previous negative detection of the 12m array survey, our ACA standalone observations in cycle 4 successfully revealed inner structures of starless cores with small-scale density enhancements or fragmentations down to ~ 1000 AU. We expand the survey to cover the entire Taurus clouds for statistical studies. The evolutional status will be investigated, and the condensation time scale will be derived. With the high density tracer of N2D+ (3-2) line, velocity fields and turbulence are to be investigated. The dense cores are expected to form inner density enhancement that becomes more compact and denser as they evolve. The turbulence dissipates monotonically, and when the central density exceeds 10^6 cm^-3, the core will fragment into substructures, and finally dynamically collapse. The pioneering theoretical core evolution models will be examined observationally for the first time. | Low-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-06-27T11:08:23.000 |
| 4600 | 2019.1.01291.S | 240 | How massive are the proto-planetary discs in Cygnus OB2? | ALMA is conducting many surveys of proto-planetary discs, but targeting nearby star forming regions. This biases our knowledge of disc masses and of the impact of the environment since those regions contain either none or only a handful (as in the ONC) of massive OB stars. We propose to use the extreme sensitivity of ALMA to survey the discs in Cygnus OB2, the closest massive star forming region to us (1.4kpc), containing 100s of OB stars. It is ideal to study the impact of extreme photoionising environments on protoplanetary discs due to its well-studied low-mass population and a thorough characterisation of the high-mass population and the associated UV field. ALMA is the only instrument capable of conducting this survey in a reasonable time. We will 1) compare the disc masses obtained with those in nearby star forming regions 2) search for a correlation between the disc mass and the stellar mass, which our models predict to be much steeper than in nearby regions 3) search for correlations between the disc mass and the UV flux received from the massive stars. Our program will characterise disc evolution in an environment completely different from those explored so far. | Disks around low-mass stars | Disks and planet formation | 2023-08-22T21:12:17.000 |
| 4601 | 2017.1.01313.S | 23 | A new window on high-energy processes in Young Stellar Objects: millimeter-wavelength flares in Orion | With unprecedented sensitivity at millimeter wavelengths on short timescales, ALMA is providing us with a new window on high-energy processes in Young Stellar Objects. At these wavelengths, we have access to synchrotron radiation from electrons accelerated to MeV energies in flares, orders of magnitude more energetic than typical energies in stellar X-ray flares. In addition to probing higher energies, we have access to the early acceleration and heating phase of a flare and not only the resulting thermal X-ray emission. The recurrence rate of millimeter-wavelength flares in YSOs is unknown in spite of their importance for our understanding of the high-energy irradiation of protoplanetary disks and its influence on planet formation as well as planetary habitability. We propose to characterize YSO millimeter-wavelength flaring variability within two pointings at the BN/KL region of the Orion Nebula Cluster since 1) it contains many well-studied, radio-bright YSOs, and 2) ALMA observations will complement our extensive JVLA and VLBA cm-wavelength observations to much higher energies. We will also study the impact of YSO flares on the constant-flux assumption in synthesis imaging. | High-mass star formation, Low-mass star formation | ISM and star formation | 2019-02-27T15:51:34.000 |
| 4602 | 2018.1.00244.S | 13 | Investigating the rotation velocity of the ionized gas slower than the Kepler speed in a protoplanetary disk | We propose to identify if the rotation speed of ion molecules is slower than the Kepler roation by using the ion molecule of H13CO+ toward the protopolanetary disk, HD 163296, because non-ideal MHD theory predicts that the ionized gas rotates slower than the Kepler rotation due to the Lorenz force. This slower velocity is known as ambipolar diffusion and is simply described by the magnetic field strength and the densities of neutral and ion gases. Therefore, the velocity shift would be direct evidence of the magnetic fields. By using ALMA archival data, we find a velocity shift of 0.5 km/s between DCO+ and C18O in HD 163296, suggesting a magnetic field strength of 5.7 mG at 100 au. However, DCO+ and CO may trace different layers and DCO+ was observed with coarse resolution. It is highly needed to investigate such slower rotation velocity with high spatial resolution by using the suitable molecule of H13CO+ tracing the same layer as the C18O. This is the first trial to obtain the direct evidence of the magnetic fields and estimate the magnetic field strengths of a protoplanetary disk. Even if velocity shift is not found, we can set an upper limit on the magnetic field strength. | Disks around low-mass stars | Disks and planet formation | 2021-02-13T03:35:46.000 |
| 4603 | 2021.A.00016.T | 14 | ALMA polarization observations of BL Lac during the first X-ray polarization campaign | Multiwavalength polarization, and in particular X-ray polarization, can be an important probe of the magnetic field geometry, acceleration physics, and high-energy emission processes of blazar jets. The Imaging X-ray Polarimetry Explorer (IXPE) recently opened a new window to the Universe through high-energy polarization. Here we propose contemporaneous polarization observations of BL Lac in multiple ALMA bands during the first IXPE campaign targeting this source and low-synchrotron peaked blazars in general. The proposed observations will supplement our planned multiwavelength campaign in radio, optical, X-rays, and gamma-rays. Comparison of the millimeter-wave, optical, and X-ray polarization and measurement of the mmopticalUVX-ray continuum spectra of BL Lac, will provide data needed to determine, for the first time, the mechanism and location of the X-ray emission, as well as test particle acceleration models in blazar jets. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2023-03-15T17:43:49.000 |
| 4604 | 2023.1.00948.S | 0 | Timing the Onset of Unexpected Dust Destruction using High-Redshift Post-Starburst Galaxies | ALMA observations of the submillimeter dust continuum are now in wide community use to measure cold gas masses at early cosmic times. This method relies on an assumed molecular gas-to-dust ratio, with a value =100 typically used. However, recent theoretical work finds that dust is preferentially destroyed as galaxies transition to quiescence, resulting in gas-to-dust ratios >1000 and enormous scatter. Recent ALMA observations seem to confirm this picture, with a sample of old z~0.7 quiescent galaxies displaying gas-to-dust ratios >500-1500. We now must understand whether this unexpected dust destruction applies only to old quiescent galaxies or also to newly-quenched objects that may even be only temporarily quiescent. We propose to measure the timescale for dust destruction using a sample of 19 recently-quenched galaxies with existing CO detections at the same epoch. Our dust continuum observations will reach 5sigma limits on the gas-to-dust ratio of 300-800 in individual sources, which will test whether dust destruction post-quenching occurs rapidly or slowly. The results of this study could have wide-reaching consequences for current and future ALMA continuum observations. | Galaxy structure & evolution | Galaxy evolution | 2025-10-04T21:19:29.000 |
| 4605 | 2019.1.00948.S | 9 | New constraints on dark matter models with strongly lensed quasars | Gravitationally lensed quasars have been established as a method to detect and quantify low-mass dark matter haloes at cosmological distances. The population of low-mass haloes is dependent on the mass of the dark matter particle, thus investigations of these lenses can give independent constraints on warm dark matter. From our successful pilot programme, we have established that with ALMA observations we can obtain a statistically significant sample of systems suitable for our analysis. By observing the prevalence of flux ratio anomalies in a sample 8 four-image lensed quasar systems, we will robustly test the cold dark matter paradigm in combination with our data in-hand. In a joint analysis, we expect to be able to exclude a thermal relic mass of the warm dark matter particle <4.1 keV. This constraint will be more stringent than limits inferred with other methods, such as a 3.5 keV limit from the Lyman-alpha forest, and has the advantage that it does not assume a galaxy formation model so will be an independent test of these other inferences. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2021-06-17T09:32:55.000 |
| 4606 | 2015.1.00118.S | 0 | Do more evolved T Tauri disks have magnetic fields like HL Tau? | To date, only one T Tauri star has been detected in polarized dust emission (HL Tau, the brightest T Tauri disk) but at a lower fractional polarization than expected (average of 0.9%). The inferred morphology of the magnetic field in HL Tau is consistent with a toroidal field, but more circumstellar disk examples are necessary to understand the importance of the magnetic field in disks. Other studies have attempted to measure the inferred magnetic field in other T Tauri disks but not at the same sensitivity (only placing limits that would not have detected HL Tau's polarization). To further understand the magnetic field in T Tauri stars and its effect on accretion and evolution, we propose to use the unique polarization capability of ALMA to measure the inferred magnetic field in three of the brightest T Tauri disks to a higher sensitivity than HL Tau (0.3% 3-sigma fractional polarization). With these data we can determine if polarized dust emission is common in other T Tauri stars, constrain the magnetic field morphology to determine if toroidal or poloidal fields dominant, and reveal any evolutionary differences in the small sample of inferred magnetic fields in disks. | Disks around low-mass stars | Disks and planet formation | 2018-10-09T22:59:28.000 |
| 4607 | 2019.1.00476.S | 10 | Temperature and density of the innermost ejecta around the Red Supergiant VY CMa | Our ALMA Cycle 5 maps of the ejecta around the Red Supergiant VY CMa have revealed it to be far more complex than anticipated. Furthermore, different lines were found to probe different structures of the ejecta. This differences in the emitting regions might be due to excitation or chemical conditions of the ejecta. However, since we count with only a single transition observed for most molecular species we could not obtain estimates of the temperature and density of the different regions. We aim to observe a selected number of transitions of the species tracing the structures observed. The combination of different transitions from a particular species would allow us to obtain pixel-to-pixel and channel-to-channel rotational diagrams, and thus obtain column density and rotational temperature maps for the different molecules. In addition we aim to observe 12CO 2-1 which would be combined with Cycle 5 data (P.I. W. Vlemmings) to obtain similar density and temperature maps but for the bulk of the molecular gas. This would allow to disentangle the physical or chemical origin of the different structures. | Evolved stars - Shaping/physical structure, Evolved stars - Chemistry | Stars and stellar evolution | 2022-10-24T16:22:39.000 |
| 4608 | 2015.1.01380.S | 0 | IRAS 15398-3359: Very Low Mass Class 0 Protostar? | In star-formation studies, an important target is to understand when and how the rotationally supported disk is formed around the protostar. In order to address this question, we recently conducted the ALMA observations of the CCH (N=4-3) and H2CO (515-414 etc.) lines in Band 7 toward the low-mass Class 0 protostar IRAS 15398-3359 at a resolution of 0."5. We detected a beautiful outflow feature as well as a flattened envelope around the protostar. From the analysis of the outflow structure, the inclination angle of the envelope is estimated to be 20 degree (i.e. almost edge-on). Then, the velocity structure of the envelope is analyzed, and the mass of the protostar is roughly estimated to be less than 0.09 Msun. Furthermore, the H2CO emission shows a sign of a Keplerian disk. These results will be an important clue to understanding the initial stage of disk formation processes, if confirmed. We here propose to observe the CCH (N=3-2) and H2CO (515-414 etc.) lines in the Band 6 and Band 7 at the resolution of 0."23 and 0."16, respectively. This observation will provide us with a deep insight into the initial stage of disk formation in Class 0 protostars. | Low-mass star formation | ISM and star formation | 2017-07-01T22:03:00.000 |
| 4609 | 2017.1.00339.S | 26 | The aligned dust grains of VY CMa: a new probe of supergiant mass loss and dust formation | The origin of high mass-loss events from evolved massive stars remains elusive. One of the best studied stars, with numerous obvious discrete ejecta, is VY CMa. Its high mass loss rate and unusual chemistry suggest that it is near the end of the red supergiant stage or possibly in a second short-lived red supergiant stage. HST and ALMA observations have revealed several arcs and clumps with apparent dust masses >0.001 solar mass ejected over the last few hundred years. Our recent ALMA band 5 study has revealed that the most prominent of the dust clumps, labelled C, appears to contain magnetically aligned dust grains. This not only allows us to study the effect of magnetic fields on the mass ejections, but also, by using spectro-polarimetry, study the detailed dust shape, size, and composition. This can only be done with ALMA. Here we propose a multi-band study complementing our JVLA and previous ALMA observations in order to characterize the temperature and dust mass in clump C. We include polarization, which, through obtaining the first polarization SED in a near-stellar environment, will additionally enable us to determine the dust alignment mechanism and grain size distribution. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-12-15T06:42:41.000 |
| 4610 | 2017.1.01373.S | 5 | Kinematics and Chemistry of (the only?) Bonafide Massive Prestellar Core | Core accretion models of high-mass star formation require the existence of gravitationally bound massive starless cores, but robust observational examples of such objects have proven elusive. We have identified an excellent candidate for a massive prestellar core in the course of our extensive studies of GLIMPSE Extended Green Objects (EGOs): G11.92-0.61-MM2. Separated by ~7" from the nearby MM1 hot core, MM2 is a strong dust continuum source, but devoid of star formation indicators. In contrast to MM1, MM2 has no masers, no cm continuum, and, remarkably, no line emission in SMA (sub)mm observations covering ~24 GHz of bandwidth. The combined physical properties of MM2, inferred from its (sub)mm continuum emission, are extreme: T~17-19 K and M>30 Msun within a radius<1000 AU, corresponding to N(H2)>10^25 cm^-2 and n(H2)>10^9 cm^-3. We propose deep ALMA observations of MM2 in H2D+, the best tracer of extremely dense, depleted gas in low-mass starless cores. Our goals are to constrain the boundedness and stability of MM2, and to test the hypothesis that MM2 is, physically and chemically, a "scaled-up" analog of a low-mass prestellar core. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-09-14T18:17:38.000 |
| 4611 | 2022.A.00030.T | 12 | A Candidate Fast Extragalactic Transient Discovered at Millimeter Wavelengths | The 10-m South Pole Telescope (SPT) is conducting a systematic half-day cadenced survey of 1500 square degrees at millimeter wavelengths (95 and 150 GHz). On 31 July SPT reported its first high-significance, strong candidate extragalactic transient, which peaked at 18.5 mJy at 100 GHz (26 July 2023) and had faded below 15 mJy (3 sigma upper limit) two days later. The dominant population of extragalactic transients at this frequency is expected to be afterglows from long-duration gamma-ray bursts, but no associated prompt GRB was detected by high-energy satellites. We propose to use ALMA to localize the event to significantly sub-arcsecond precision and measure the cm-mm SED of the emission, which is essential for determining the transient's astrophysical origin. If extragalactic, this would be the first extragalactic transient discovered by a millimeter survey and followed up in real time, and could be the first member of a long-hypothesized phenomenon such as an off-axis gamma-ray burst. | Transients | Stars and stellar evolution | 2024-03-01T00:52:17.000 |
| 4612 | 2018.1.00298.S | 4 | Protoplanetary Disk Magnetic Fields from the Zeeman Effect | Magnetic fields are thought to drive turbulence, launch winds, and may even be partly responsible for the ubiquitous ring-like substructures observed in protoplanetary disks. However, there are still no direct observational constraints on strength and/or geometry of the magnetic field in a Class II disk. Given the recent discovery of ambiguities in the interpretation of thermal dust polarization in disks, we need a different, more direct tracer: circularly polarized line emission. We aim to detect the Zeeman effect in CN toward the nearby, gas-rich disk around the solar-mass star AS 209. The first-order goal is to detect the presence of a magnetic field for the first time in a disk. We will also estimating the field's strength and geometry (i.e., Is it primarily toroidal as models predict? Or is there a significant vertical component, as some earlier wind models suggest?) The proposed observations -- enabled for the first time this cycle with ALMA -- will provide critical constraints for models of magnetically driven processes in disks. | Disks around low-mass stars | Disks and planet formation | 2021-01-17T18:26:54.000 |
| 4613 | 2022.1.00542.S | 99 | Direct Measurements of the CMB Temperature across Cosmic History | A new method to constrain LambdaCDM has recently been discovered by directly measuring the CMB temperature TCMB to much higher redshifts than previously possible based on the galaxy cluster SZ effect. The new method is based on the detection of H2O absorption against the CMB due to cold gas associated with the dusty massive starburst HFLS3 at z=6.34. This effect is due to a combination of CMB excitation of the H2O ladder and pumping by the starburst radiation field. RADEX models suggest that the effect should be measurable out to z>12, but that it should disappear below about z~4.5 towards typical dusty starbursts, if TCMB scales as predicted by LambdaCDM. We here propose to test the model predictions and refine the method by targeting a sample of ten dusty starbursts at z=4.2-5.1, as well as to improve the statistical accuracy by increasing the sample size and including some of the best-studied galaxies at these epochs. | Starburst galaxies, Cosmic Microwave Background (CMB)/Sunyaev-Zel'dovich Effect (SZE) | Active galaxies | 2024-02-04T02:18:49.000 |
| 4614 | 2019.A.00002.S | 78 | A Unique View of 2I/Borisov: an ISO in Large Particles | The Interstellar Objects (ISO) passing through our Solar System offer a rare opportunity to probe the physical and chemical processes involved in solid body and planet formation in extrasolar systems. While observations of the first ISO, 1I/2017 U1 ('Oumuamua) led to constraints on its outgassing from dynamical modeling, no direct detection of the ejected material was made. Here, we propose to characterize the newly discovered second ISO, 2I/2019 Q4 (Borisov), (MPEC R106). Unlike 1I/'Oumuamua , 2I/ Borisov has shown evidence of cometary activity, meaning that investigations of the mass-loss is possible for this object. Our goal is to map the thermal continuum from 2I/Borisov over four ALMA bands, 3, 4, 6 and 7, so as to measure the dust mass and place constraints on its particle size distribution. The ALMA observations will complement our ESO observing campaign to yield strong constraints on the mass-dominant millimeter-sized or larger particles in the coma of 2I/Borisov. The superb sensitivity of ALMA provides the only way to study large particles of the second ISO in unprecedented detail. | Debris disks, Solar system - Comets | Disks and planet formation | 2020-09-23T13:45:41.000 |
| 4615 | 2012.1.00984.S | 3 | Picking Up the Pieces: Measuring the Dust and Molecular in the Prototypical BCD | We propose to observe the continuum spectral energy denstribution (SED) and the accessible CO spectral line energy distribution (SLED) of the prototypical blue compact dwarf (BCD) galaxy II Zw 40. BCD galaxies represent one of the most extreme modes of star formation in the local universe. These galaxies have low metallicities, correspondingly low dust-to-gas ratios, low masses, and extremely high specific star formation rates and star formation rate surface densities. The interstellar medium (ISM) in these metal-poor starbursts is affected by these conditions, but a detailed understanding of star formation and the ISM in BCDs (and similar galaxies) has been hampered by the lack of sensitive mm/sub-mm observations. Line and continuum observations across this regime trace the mass and physical state of both star-forming molecular gas and dust. With relatively short integrations in Bands 3, 6, 7, 9 we will gain deep physical insight into the energetics and physical conditions of the prototype BCD. We will measure the physical state (density, temperature) and mass of the molecular gas, quantify the balance of thermal dust and free-free continuum emission vs. wavelength, and place exquisite constraints on the dust mass and spectral slope. Combined with existing VLA and shorter-wavelength data, we will assemble the most complete SED to date of a low metallicity starburst. This will yield both physical insight and an observational template to inform line and continuum observations of star-forming galaxies and galaxy populations at all redshifts. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2015-11-07T20:17:53.000 |
| 4616 | 2013.1.00338.S | 21 | Rotating and expanding gas in protoplanetary nebulae | Disks rotating around post-AGB stars should play a fundamental role in the formation of planetary nebulae, since they are needed to explain the post-AGB axial jets and the resulting axial symmetry of the whole nebulae. However, the lack of observational information prevents the proper study of their role in the late stellar evolution. Single-dish observations have shown that the presence of Keplerian disks in low-mass post-AGB nebulae is very common. Recently, spectacular ALMA maps of one of this objects, the Red Rectangle, have confirmed the equatorial disk in rotation, also revealing the presence of an axial slow flow and allowing a detalied description of the complex nebula. However, this object remains the only AGB or post-AGB source in which one of such disks has been properly mapped until now and observations with other interferometers have been found to be not accurate enough to study these structures. We propose to perform maps of 12CO and 13CO J=3-2 emission (as well as of the adjacent continuum) in two similar objects, IRAS 08544-4431 and IW Car, the best candidates to continue our study, in which ALMA (and only ALMA) can yield accurate maps of the expected components. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2016-09-10T10:13:13.000 |
| 4617 | 2012.1.00119.S | 0 | A new hot, diffuse molecular component in the nuclear bulge of the Milky Way | Until recently, our view of the Central Molecular Zone (CMZ, i.e. the innermost few 100 pc) of the Milky Way was that it consists of basically two phases: dense and warm molecular Giant Molecular Clouds (GMCs) and a thin, hot and highly ionized component that fills the remaining volume. It was thought that this view can also be applied to the central regions of many other galaxies. Recently, however, Geballe & Oka (2010) detected widespread and broad (100-200 km/s) H3+ and CO infrared absorption toward point sources sources in the CMZ, which they claimed to represent a diffuse molecular medium which is widespread in the CMZ and which can be characterized by low densities and high temperatures (e.g. <100 cm-3, 300K). Although the absorption seems to be ubiquitous for CMZ clouds, little is known about the volume filling factor, mass, the detailed excitation conditions (n(H2), T_kin) and chemical composition. It has not yet been studied, to our knowledge, in microwave or mm molecular transitions, although it might be similar to a component seen in absorption toward a high z quasar arising from an intervening galaxy. We propose a pilot project to look for mm absorption lines toward a quasar close to the direction of the galactic center in order to confirm and characterize this new phase. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2015-09-15T17:52:15.000 |
| 4618 | 2015.1.00627.S | 21 | Driving molecular gas flows with radio bubbles in A2052's brightest cluster galaxy | Chandra X-ray observations of the hot atmosphere around the dominant central galaxy in the nearby cluster A2052 reveal a complex network of buoyantly rising radio bubbles, weak shocks and pressure waves, all powered by the AGN jet. Luminous, Halpha-emitting filaments appear drawn up around the edges of the northern radio bubble. The morphology and velocity structure suggest that these filaments have been uplifted from the galaxy by the bubble's expansion and entrained in the wake. We propose ALMA observations of CO(2-1) emission with 0.2 arcsec angular resolution to map the velocity structure of the inner filaments, search for outflowing cold gas entrained in the radio bubble's wake and compare the outflow rate with the jet power to investigate the jet-cloud coupling. We will also probe the central 100pc around the AGN, approaching the Bondi radius, to determine if feedback is fuelled by the accretion of the hot atmosphere or cold molecular gas. | Outflows, jets, feedback, Galaxy groups and clusters | Active galaxies | 2017-12-15T00:02:11.000 |
| 4619 | 2018.1.00058.S | 104 | A unique and massive z=4.3 protocluster from the South Pole Telescope 2500 deg^2 survey. | We propose line spectroscopy and continuum imaging towards the densest protocluster discovered so far, SPT2349-56 at z=4.3. This system has been confirmed, using ALMA in Cy4, to have at least 14 ULIRGs/SMGs detected in dust, CO, and C+ emission within 20" (integrated SFR of ~10^4 Msun/yr). Since it was found in a blind 1.4-mm survey of 2500 deg^2, it is unlikely there are many other systems like these in the entire sky. The proposed wider field and resolved observations are essential to obtain an unbiased, coherent census of galaxy population in this truly unique protocluster field. Our main goals are threefold (i) characterize the environment, by searching for cluster members in an 8 position mosaic surrounding the LABOCA-detected structure; (ii) determine whether the 4 offset (~2') red SPIRE/LABOCA sources with z_phot~4.3 are in the protocluster -- Given the high density of ULIRGs already detected, we expect to detect a plethora of fainter CO emitting galaxies at z=4.3. And (iii) resolve the 14 core cluster members in C+ and CO7-6/CI/H20 to determine whether they are merger driven or relaxed disks (probing gas, dynamical and stellar masses; multi-line diagnostics of the ISM). | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2020-01-04T16:09:47.000 |
| 4620 | 2018.1.01824.S | 112 | A large sample of MS galaxies with CO detections at 3<z<4 | CO detections are crucial to probe the molecular gas in normal star-forming galaxies, where most of the star-formation in the Universe takes place. Since Cycle 3, we started a campaign to detect mid-high CO transitions in normal star-forming galaxies in the Early Universe: to maximize ALMA efficiency, we target galaxies already detected at sub-mm wavelengths by ALMA and with reliable spectroscopic redshifts. With our Cycle 3-4 program we detected two CO transitions in 5 main-sequence star-forming galaxies at 3 | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 2020-11-19T21:02:28.000 |
| 4621 | 2016.2.00171.S | 37 | Large-scale cold gas structure in protostellar envelopes | Stars form out of collapsing cold dense protostellar envelopes. Passively irradiated protostellar envelopes are surrounded by a substantial amount of cold gas. In these cold regions, CO freezes out on the grains and other molecules such as DCO+ are enhanced. The chemical differentiation allows us to target the enhanced molecular species to probe the CO dark infalling flows. Only ALMA with its high surface brightness sensitivity and correlator flexibility can deliver these lines. Our previous observations show that multiple tracers are needed to probe the entire infalling gas. Data in band 4 were previously obtained with 10 minutes of integration. Due to the lack of uv coverage, strong sidelobes are present at the regions of interest. A better uv coverage characterized by less than 20% sidelobes can be obtained with at least 3 hours of integration per source. Higher sensitivity and image quality allow for better quantification of the extent of the cold gas emission. These maps are needed to examine the flow of the gas into the inner envelope, disk, and protostar. The cold gas flow will give estimates on the pristine material entering the disk. | Low-mass star formation, Astrochemistry | ISM and star formation | 2019-02-22T18:44:24.000 |
| 4622 | 2022.1.01635.S | 0 | Characterize the protostellar disk population in an IRDC | Protostellar disks play important roles in star formation, and their observed properties set the initial conditions for disk evolution and planet formation. To date surveys of disks in the protostellar phase are mainly limted to relatively evolved nearby regions such as Orion and Perseus, so it is largerly unexplored how the ensemble properties of protostellar disk, e.g., mass and size distributions, would vary in different environments. Here we propose to utilize the long baseline capability of ALMA to conduct a Band~7 survey towards the disk population in a distant massive infrared dark cloud (G14.19), which is in a very early stage of cluster formation. Thus the proposed observation will not only enable us to examine if disk formation undergoes similar regulation in this special physical condition, but also serve as a template and motivate large sample surveys in future. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2024-12-05T01:09:51.000 |
| 4623 | 2018.1.00616.S | 64 | Anatomy of a spectroscopically-confirmed lensed galaxy at z=9.11 | In our ALMA Cycle 4 observations, we have spectroscopically confirmed a redsfhit (z)=9.11 lensed galaxy selected in the HST Frontier Fields survey, detecting the [OIII] 88 micron line at a peak significance level of 7.4-sigma in Band 7. The object (JD1) is the highest-z emission line galaxy to date, and offers us a unique opportunity to investigate detailed properties of galaxies at z>9 for the first time. Our accepted Cycle 5 DDT program will target the [CII] 158 micron line to investigate chemical properties of JD1. Here we propose to perform deep high angular resolution observations of [OIII] 88 in Band 7. ALMA's unique capability will reveal the internal structure of JD1, a lensed source, with sub-kpc intrinsic resolution, providing valuable kinematic data to test for rotational and merging substructures and gaseous outflows/inflows. As a lensed z>9 source JD1 provides the natural target to demonstrate the future potential of similar studies with JWST and ELTs. An important byproduct of this proposal will be a significant improvement in the dust continuum emission limit with important constraints on dust production, growth and destruction mechanisms in the reionisation era. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-12-31T18:50:55.000 |
| 4624 | 2017.1.01539.S | 108 | Where's the oxygen in Sgr B2? | Thanks to space and stratospheric telescopes (Herschel, SOFIA) and to hard-core radiative transfer modeling we have been able to acquire a detailed knowledge on the whereabouts of gaseous H2O and, by proxy, of elemental oxygen in the Sagittarius B2 complex. Our three-dimensional model of ~70 rotational transitions of H2O and its isotopologues yields [H2O]/[H2]~10^(-6). However, with increasing gas temperatures we expect H2O to account for about 50% of the total oxygen (the other half being tied in CO). If our assumptions on oxygen chemistry are correct, we would expect [H2O]/[H2]~10^{-4} in the vicinities of the hot cores. With this experiment we want to put this assumption to the test. We think that our Herschel data cannot answer this question, because of the combined effect of large beam and high dust opacity. We propose to observe vibrationally excited H2O and H218O at 658 and 647 GHz with the ALMA 12-m array towards Sgr B2(M) and (N). These transitions lie ~2400 K above ground and, with our desired spatial resolution of 0.22", we will catch a glimpse of the inner 0.01 pc of the cores, and finally determine the whereabouts of elemental oxygen in dense hot gas. | Intermediate-mass star formation, Astrochemistry | ISM and star formation | 2020-07-09T00:00:00.000 |
| 4625 | 2019.1.00592.S | 20 | The physical conditions and spatial structure of the dust formation zone of IRC+10216 | We propose to study the innermost zone (1-20 R*) of IRC+10216 through the systematic observation of a significant number of vibrationally excited lines of abundant species such as HCN, HNC, SiO, SiS, SiC2 and CS. The highest angular resolution of ALMA band 6 (0.02") is requested to resolve the stellar photosphere and the region of a few stellar radii where dust molecular seeds are formed, and where shocks could be controlling the chemistry and the dynamics of the envelope. The physical conditions across the dust formation and growth zone (1-20 R*) will be fully characterized using lines from vibrationally excited states up to 15000 K in energy. We expect to obtain a unique data set from which the physical conditions and spatial structure of the gas across these inner regions will be derived. In addition, we will trace the presence of shocks, and unveil the recent mass loss history of this prototypical C-rich AGB star. These observations will also provide strong guidelines for astrochemical models, and laboratory experiments on the properties of stardust analogues. | Evolved stars - Chemistry | Stars and stellar evolution | 2022-11-15T09:35:18.000 |
| 4626 | 2022.1.00403.S | 528 | Linking the Resolved Filamentary Molecular ISM to Massive Star Formation across M33 | Milky Way studies show that the molecular ISM is filamentary on few pc scales, including recent discoveries of large-scale galactic filaments, but coarse resolution in extragalactic observations has stifled direct comparisons beyond the Milky Way. We propose observations to enable this comparison with complete mapping of M33's inner star-forming disc (25 kpc2) to resolve filamentary molecular clouds on 4 pc scales, down to masses of 900 Msol (5-sigma). We will efficiently detect widespread 12CO & 13CO(2-1) to (1) identify how galactic structure shapes the molecular ISM morphology in different environments (centre vs. spiral arms vs. inter-arms); (2) trace molecular clouds from formation to dispersal, building a resolved view of the molecular cloud lifecycle; (3) resolve whether filamentary morphology influences where massive star form, testing predictions from competing star formation theories. This survey enters a new regime in molecular cloud studies by resolving similar scales to Galactic plane surveys across a complete external star-forming disc. Combined with HST, VLA, and Cycle 1 JWST observations, these data will be a definitive legacy product for molecular cloud studies. | Giant Molecular Clouds (GMC) properties | ISM and star formation | 2024-04-19T20:51:55.000 |
| 4627 | 2015.1.01433.S | 77 | Exploring the unidentified gamma-ray sources in the Galactic plane with ALMA | About 30% of all gamma-ray sources detected by Fermi/LAT are still unidentified, i.e. they lack at least one low energy counterpart. The identification of these highly energetic sources is one of the four main scientific objectives of the Fermi/LAT mission. The largest population of associated gamma-ray sources are blazars. However, due to absorption, scattering, and source confusion, less gamma-ray blazars are found close to the Galactic plane as expected for an isotropic distribution. With this exploratory study, we propose ALMA observations at 100 GHz and 230 GHz of 5 unassociated gamma-ray sources at low galactic latitude with no radio counterpart to confirm their nature as hidden blazars. These sources are broadband emitters, such that we select only sources which have possible X-ray counterparts from Swift/XRT observations. Our proposed study will be the first step toward a better understanding of different populations of gamma-ray sources. It will open a new window for their investigation using high radio frequencies, having a high potential to discover new gamma-ray source classes. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-05-21T20:03:25.000 |
| 4628 | 2016.1.00801.S | 125 | The origin of high-mass star-forming regions: role of filaments and global collapse | Virtually all star-forming regions show filamentary structures. Whether these filaments are coherent, monolithic structures that connect multiple star-forming regions, or are composed of multiple subunits is presently poorly known, as is the answer to the fundamental question regarding their role in accumulating mass in the sites of active star formation. We select precursors of high-mass star-forming regions hosted in isolated filaments, to address these issues: the best 6 candidates were identified out of the complete ATLASGAL catalogue of 10000 sources. We propose to observe the spine of these filaments and its surroundings with the ACA to map their velocity field, looking for ordered mass flows and signs of large/scale infall. The large-scale kinematics around these objects is still undisturbed, reflecting the initial conditions of high-mass star formation. Competing theories of star formation predict a different contribution from the environment in terms of gas accreted onto massive clumps, allowing the proposed observations to distinguish between them. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-05-30T00:00:00.000 |
| 4629 | 2023.1.00572.S | 184 | Chasing streamers: Unveiling the connection between disk growth and infall channels in embedded protostars | The recent rise in the discovery of streamers, asymmetric channels of infall toward the protostellar disk, show that the local environment around protostars influences their evolution beyond their main accretion phase. In particular, the presence of streamers towards embedded protostars suggests that the total mass within disks is replenished and possibly increases, right at a critical evolutionary stage to kickstart planet formation. However, there are not enough protostars with their envelopes characterized to evaluate the influence of streamers in the mass accretion process. We propose a systematic search for streamers towards near-by star-forming regions, including Perseus and Orion, to determine if the presence of streamers correlates with high accretion rates. We build a sample of 43 protostars, out of which we request ALMA 12m and ACA observations of 32 of them, to derive statistically significant correlations. We will determine if the presence of streamers correlates with high accretion rates (>10^-7 Msun/yr) towards protostars, and quantify the effects of streamers on protostellar disks' growth. | Intermediate-mass star formation, Low-mass star formation | ISM and star formation | 2025-11-19T12:52:38.000 |
| 4630 | 2018.1.00701.S | 7 | CO polarization observations to verify magnetic field effects on kinematics around the protostar TMC-1A | We propose ALMA observations toward the Class I protostar TMC-1A in polarized CO isotopologues and 1.3 mm continuum emission. Our Cycle 0 ALMA observations in 12CO (2-1), C18O (2-1), and 1.3 mm continuum show that the 12CO emission traces the associated outflow, while the C18O emission traces a Keplerian disk and an infalling and rotating envelope surrounding the disk. The central stellar mass is estimated from the Keplerian rotation to be 0.68 Msun. Our model fitting provides the disk radius of 100 au, the inclination angle of 65 degree, and interestingly the infall velocity 0.3 times as slow as the free fall velocity. This slow infall can be explained by magnetic fields (B-fiels) with ~2 mG amplitude. In order to verify this hypothesis, we will measure B-field geometry in the outflow and the disk using the polarized molecular lines and continuum. This proposed study follows our previous polarization observations with ALMA toward the protostar NGC1333 IRAS 4A. The B-field strength will also be constrained through the Chandrasekhar-Fermi technique. | Low-mass star formation | ISM and star formation | 2023-01-29T07:27:58.000 |
| 4631 | 2018.1.00236.S | 39 | Obscured star formation of the brightest galaxies at z~8 | The recent confirmation of luminous galaxies (MUV<-22) at z=8-11 has demonstrated that galaxy formation was well underway in the early universe, motivating a study of the brightest galaxies forming at z>=8. To this end, we used the recent UltraVISTA DR3 data and the latest IRAC observations of the SPLASH and SMUVS programs, to compile a sample of 16 bright H=24-25 (MUV = -22 to -23), massive ~10^10 Msun galaxies at z=8-10 over COSMOS. Massive galaxies are expected to be significantly obscured, based on stellar population model fits, lower redshift IRX-beta relations, and theoretical models which require substantial attenuation to match the observed UV LF. In Cycle 5, we were awarded ALMA 1.2 mm and 1.5mm continuum observations to test for the presence of dust in the 8 brightest galaxies from our sample. With this resubmission, we request time to complete the program. Our observational setup has been tuned to allow us to serendipitously detect [CII] in ~2 sources in our sample (assuming similar [CII]/SFRs as found by Smit+2018). These observations are vital to understand the bolometric properties of the galaxies and to compare to the prediction of theoretical models. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2020-01-31T22:58:25.000 |
| 4632 | 2019.1.00134.S | 6 | HL Tau: The "Rosetta Stone" For Understanding the Origins of Disk Polarization | HL Tau shows completely different polarization morphologies in Bands 3, 6, and 7. At Band 3, the morphology is azimuthal, and the polarization has been attributed to grains aligned perpendicular to the radiative anisotropy. At Band 7, the morphology is consistent with self-scattering. Band 6 shows ~50/50 mix between the two morphologies. However both models explaining the polarization patterns have severe problems. While the scattering model has a strong prediction for how the polarization percentage should vary with wavelength and how large the dust grains can be, the predicted slope in the polarization spectrum is not observed, nor do the modeled grain sizes match studies of the dust opacity index. Moreover, the model for grains aligned with the radiation anisotropy predicts a morphology for the polarized intensity that was not seen at 0.36" resolution in Band 3. If we confirm this missing feature with higher resolution Band 4/5 observations, it would cast serious doubt on this alignment mechanism. We propose polarimetric observations of HL Tau in Band 4 and 5 at 0.2"/0.16" resolution, which will allow us to discern how disk polarimetry can be used to constrain grain sizes. | Disks around low-mass stars | Disks and planet formation | 2022-09-01T16:08:38.000 |
| 4633 | 2022.1.00505.S | 36 | Hunting prestellar cores in high-mass star-forming regions: a comparison between oH2D+ and N2D+ | High-mass stars play a key role in shaping the evolution of galaxies, regulating the energy budget of the interstellar medium, and the formation of Sun-like systems in dense clusters. ALMA has begun to revolutionize our understanding of the global and local physics involved in this complex process. However, the characterisation of the initial prestellar conditions is left unexplored and provides a major source of uncertainty. This proposal aims to establish the best tracer (in terms of costs/benefits) of prestellar cores. Previous ALMA data demonstrated that oH2D+ is a unique and unambiguous tracer of prestellar conditions that would be otherwise unidentified in conventional methods. A few recent observations claim that N2D+ is a good tracer of prestellar cores. However, due to the lower resolution, a 1-1 comparison has been impossible. Here we target N2D+ (3-2) and (4-3) in two high-mass clumps already observed in oH2D+, to compare the three tracers at the same spectral/spatial resolution and finally establish which tracer is the best to identify prestellar cores, and provide a good estimate of the whole core mass budget in high-mass star-forming regions. | Astrochemistry | ISM and star formation | 2024-05-17T18:05:14.000 |
| 4634 | 2012.1.00097.S | 4 | Unwinding the secret of the recent thermal pulse and sculpted wind in R Sculptoris | We propose to observe the detailed structure of the spiral shape around the carbon Asymptotic Giant Branch (AGB) star R Scl in CO line emission in band 6. The circumstellar envelope (CSE) around R Scl was recently observed during ALMA Cycle 0. The Cycle 0 data clearly show the detached shell - a consequence of a recent thermal pulse. Amazingly, the data also show a spiral structure which extends from the central star to the detached shell, indicating an unknown binary companion that is shaping the wind from the AGB star. The observed spiral has opened a new window to observationally constrain the thermal pulse cycle, as well as the effect of companion stars on the shaping of stellar winds. In order to fully exploit the Cycle 0 data, the parameters of the binary system (eccentricity, inclination, period, primary and companion masses), need to be known in detail. For this we need to measure deviations from a perfect spiral, resolve the binary system, and accurately measure the contrast between the winding and inter-winding regions. The ALMA Cycle 1 array is the only instrument with the required spatial resolution and sensitivity to achieve this. The proposed observations will improve the resolution and sensitivity of the Cycle 0 data by factors of 10 and 20, respectively, allowing to determine the parameters of the binary system in detail. In addition to observationally constraining the thermal pulse cycle, the results will give information on the shaping of the stellar wind and the formation of planetary nebulae, and hence lead to a deeper understanding of this important stage of stellar evolution. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-11-14T00:00:00.000 |
| 4635 | 2017.1.01235.S | 199 | High Resolution Survey of the Gas and Dust Distribution in Nearby Luminous Infrared Galaxies | We propose to observe six of the closest U/LIRGs which we have already observed with the VLA at 0.1 at 33 GHz. ALMA observations at Band 3 and 7 will resolve the nuclear warm molecular gas and dust, ideal for comparison to our star-formation tracing VLA data. By combining 100 and 33 GHz continuum, we will diagnose the nature of the radio continuum at each point in the nuclear dis. Our observations will provide a strong test of the common assumption that the sizes inferred from optically thin, star-formation radio continuum also describe the distributions of gas and dust. From the high resolution CO and dust data, we measure the structure and kinematics of the gas in the inner disk. In addition to dynamical mass estimates and constraints on SMBH masses, these measurements are crucial to understand if the local ULIRG population indeed consists of radiation pressure limited maximal starbursts. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Galaxy evolution | 2018-12-08T22:16:25.000 |
| 4636 | 2019.1.00362.S | 11 | Revealing the presence of accretion shocks | In low-mass star formation, the chemical composition of the early disk sets the conditions for planet formation. Models predict that material from the envelope falls onto the disk and produces accretion shocks, increasing the temperature and desorbing molecules from dust grains. This process would explain the observed abundances of key species, such as SO2. However, there is not solid evidence that accretion shocks indeed exist and spatially resolved observations of the relevant molecular line emission at disk scales are crucial for a better understanding of this physical process. We propose to observe Oph-IRS 44, a Class I source that shows strong, warm, compact, and broad SO2 emission in previous ALMA data. The detected emission is possibly tracing accretion shocks. With higher spatial resolution, its spatial distribution and spectral features will be analysed in detail and will allow us to distinguish between the accretion shock and other scenarios, such as disk winds or outflows. These observations will provide strong evidence for the presence (or absence) of accretion shocks and their importance in setting the physical and chemical properties of circumstellar disks. | Low-mass star formation | ISM and star formation | 2022-06-11T18:31:11.000 |
| 4637 | 2021.1.01221.S | 11 | The molecular gas content in star-forming z~1.5-2.3 galaxies with AO-aided IFU Halpha spectroscopy | We propose to observe the global molecular gas content in a sample of 14 star-forming galaxies at z=1.47 and 2.23 presenting exquisite multi-wavelength coverage, including natural seeing VLT/KMOS, and AO-aided VLT/SINFONI or KECK/OSIRIS IFU spectroscopy. These available data provide ~0.15" imaging of the Halpha emission line, probing the kinematical details of the ionised gas in disk-like thick-disk clumpy galaxies. The targets are representative to the bulk of the high-z galaxies, and measuring their molecular gas content (M_H2) provides a unique way for estimating the effects induced by their gas content in their internal properties. In particular, we use band-3 to detect at low resolution the CO(2-1) or CO(3-2) emission line for galaxies at z=1.47 and 2.23, respectively, allowing a global estimate of M_H2, depletion times via M_H2/SFR and gas fractions. The proposed 14 galaxies aims to double the number of galaxies with CO detections at z>1. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2023-04-27T10:30:00.000 |
| 4638 | 2017.1.00046.S | 611 | Star Forming Main Sequence at z = 0.3 to 3 | We propose completion of our very successful ALMA survey of the ISM contents of galaxies at the peak epoch of cosmic star formation (z = 0.3 to 3). These observations probe ISM masses using the long wavelength dust continuum emission in 575 galaxies with only 2-3 min per galaxy. For Cycle 5, a sample of 200 galaxies at z = 0.3 to 3 is selected on the main sequence (MS) with specific SFRs (sSFR = SFR/M) ranging from 0.5 to 2 times that of the MS. Our published sample (from our earlier ALMA observations plus all available archive observations) was highly biased towards starburst galaxies (SB) with sSFR factors of 2 - 20 times the MS sSFR; the present sample, focussed on the MS, will enable precise characterization of the difference between the SB and MS galaxies -- be it larger ISM masses and/or larger SF efficiencies above the MS. The combined sample will span specific star formation rates from 0.5 to 20 times that of the MS over the redshift range 0.3 to 3. The major goal of this new work is to understand the differences between the MS vs SB galaxies: smooth ISM distributions vs clumpy and/or concentrated; single disks vs merging pairs. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2019-12-18T16:28:01.000 |
| 4639 | 2011.0.00191.S | 0 | Constraining the Formation Mechanisms of Wide-Orbit Planets: The Case of Fomalhaut b v0.6 | Fomalhaut b is one of the first planets to be directly imaged. Its separation from Fomalhaut is measured to be 115 AU, which presents a challenge to planet formation theories. Additional observations around other stars have shown that Fomalhaut b is not a rare outlier, but one of many wide-orbit planets. These objects may represent an extreme outcome of planet formation at shorter periods or an entirely separate mode of planet formation. A circumplanetary debris disk has been suggested to explain the excess optical brightness of Fomalhaut b. We propose to observe this potential debris disk as well as the known circumstellar ring, and use these observations to place strong constraints on planet formation at wide orbits. | Debris disks, Exoplanets | Disks and planet formation | 2012-12-06T20:39:39.000 |
| 4640 | 2015.1.00555.S | 6 | Disks, winds, and tori -- towards a comprehensive view of the AGN environment with VLTI and ALMA | We want to explore the origin of dusty molecular outflows in AGN by combining data from the highest angular resolution IR and sub-mm facilities VLTI and ALMA. Using VLTI we recently showed that the "dusty torus" region is much more complex than models assume: Radiation pressure may drive a clumpy wind that forms a polar outflow. This outflow seems responsible for the bulk of the mid-IR emission seen on <10 pc scales of nearby Seyfert galaxies and may be the origin of kpc scale molecular outflows that are invoked in AGN feedback. While this disk+wind picture emerged from detailed VLTI observations, it lacks an exploration of its physical implications: dense molecular gas orbits the black hole and dense clouds are ejected into the outflow. In this pilot study we want to observe NGC 3783, the poster child of the pc-scale "dusty outflows", by mapping the kinematics of J=4-3 high-density tracer lines of HCN, HNC, CO, and HCO+. Do we see the dense rotational disk? Can we prove a significant outflow? And does the IR dust emission trace the high-density regions? These questions can only be solved directly with the unprecedented exploitation of maximal angular resolution of ALMA and VLTI. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2018-12-08T14:11:09.000 |
| 4641 | 2016.1.01309.S | 21 | Imaging High-Velocity Neutral Gas around an Intermediate-mass Black Hole Candidate | We propose subarcsec-resolution wide-field imaging of CO-0.40-0.22, which is a peculiar compact cloud with an extremely broad velocity width (dV ~ 100 km/s) found in the central molecular zone of our Galaxy. Our main goals are to: (1) determin the molecular gas kinematics in this cloud, (2) probe ultra-high velocity neutral gas, and thereby (3) confirm the existence of an invisible massive (M ~ 1E5 Msun) object within the cloud. Our target, CO-0.40-0.22, will be fully mapped in HCN J=4-3 and CI 492 GHz lines at linear resolutions of 0.021 pc and 0.017 pc, respectively. These ALMA data sets will be combined with those obtained with the ASTE 10 m telescope to recover spatially extended emission. This project is going to reveal unprecedented details of this peculiar molecular cloud, which constrain the size of the putative massive object within the cloud, allowing us to examine whether the invisible object is an intermediate-mass black hole. | Galactic centres/nuclei | Active galaxies | 2018-04-27T22:32:26.000 |
| 4642 | 2021.A.00030.S | 10 | A critical epoch for quasi-simultanous X-ray/radio/mm characterization of a highly variable blazar at z=7 | Quasi-simultaneous VLA, XMM and NOEMA observations were approved to study the physical properties of the first blazar known at z=7. Alas, the XMM observations were only recently scheduled and executed on Aug 4 2022-almost a year after the radio/mm observations! Due to the extreme observed variability (>50% in <1 yr), this delay means that the X-ray and radio/mm measurements will be unconnected. A special VLA request was approved right after the XMM observations, providing a new radio epoch on Aug 6. Contemporaneous mm data are still lacking. The 2021 NOEMA results are puzzling: the star-formation rates derived from the strong continuum and from the weak/inexistent(?) [CII] differ by >1 order of magnitude. We request ALMA Cycle 8 observations to collect the key mm data with a minimal delay of 2-7 days (rest-frame) from the latest X-ray/radio data. We note that a [CII] non-detection would imply a star formation rate <5 Msun/yr, unprecedented for a high-redshift quasar host and a limit only achievable with ALMA. Synergistic ALMA/VLA observations will allow us to constrain the star-formation properties and search for signs of radio-mode feedback on the most distant radio source known. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2023-03-06T22:40:15.000 |
| 4643 | 2018.1.00231.S | 205 | Obscuration to Reionization: A Blank-Field 2mm Deep Survey in COSMOS | Obscured star-forming galaxies are the dominant sources of cosmic star-formation at z~2-3, yet our knowledge of their ubiquity at earlier times (z>4) is unconstrained. The census of galaxies at z~>4 has relied almost exclusively on optical/infrared (OIR) tracers, though tools like the Lyman-break galaxy selection technique selects against obscured starbursts by design. We propose 40.5 hours of band 4 (2mm) time to map 0.18x0.36deg^2 to 90uJy/beam RMS to place the first constraints on the obscured contribution to the star-formation rate density at z>4 using direct, unbiased millimeter tracers. Mapping at 2mm rather than shorter wavelengths provides significant advantage to finding the highest-redshift dust emitters due to the shape of the negative K-correction, where lower redshift obscured galaxies - that make up the majority of detections in 1.2mm maps - are filtered out. We will detect between 15-80 sources and use a new backward-evolution model to constrain the z>4 infrared luminosity function (IRLF) via measurement of 2mm number counts. A rich set of ancillary data in the proposed map area will give constraints on source redshifts to refine IRLF constraints during the EoR. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2020-08-20T17:35:21.000 |
| 4644 | 2024.1.01463.S | 0 | Pre-processing of galaxies in two groups near the Virgo cluster | A significant fraction (~40%) of cluster populations is accreted through galaxy groups, and the group environment affects member galaxies, making them red and passive before they fall into a cluster. This pre-processing can produce the quenched galaxies at the outside (or the outskirts) of the cluster. Thus, it is crucial to study the impacts of pre-processing on group members to obtain a full picture of galaxy evolution in a hierarchical universe. In particular, probing the molecular gas properties is a key to understanding the quenching of star formation in the group environment. Therefore, we propose to obtain 12CO (1-0) imaging data of 25 galaxies of the NGC 4636 and NGC 4261 groups, using the Atacama Compact Array (ACA). These two groups near the Virgo cluster, which show that some group members have low star formation rates and low cold gas fractions, are ideal laboratories to study pre-processing. By combining the ACA CO data with multi-wavelength data (HI, optical, UV, IR, and X-ray), we will investigate how significantly pre-processing affects 1) CO structures in both distribution and kinematics and 2) star formation processes of group members. | Surveys of galaxies, Galaxy groups and clusters | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 4645 | 2015.1.01302.S | 7 | The source region of plumes of Europa | The 2014 report of a watery plume at the south pole of Europa was perhaps the most exciting and important news about this high profile satellite of Jupiter in a decade. With plans for a dedicated spacecraft mission already underway, the existence of plumes would allow the very exciting possibility of directly sampling materials from the ocean beneath the ice shell. Unfortunately, after much HST time has been devoted to trying to redetect plume emission, it remains unclear whether Europa actually has any plumes at all. Using an analogy to plumes at Enceladus, we show that plumes at Europa could have substantial thermal signatures. With the resolution and sensitivity now available at ALMA, a complete thermal map of the surface of Europa should be capable of identifying not only thermal emission from polar plumes, but also any remnant thermal emission from decades-old resurfacing events on the satellite crust. A short series of ALMA observations has the capability of finally making the first concrete confirmation or refutation of the possibility of currently activity geology on the surface of Europa. | Solar system - Planetary surfaces | Solar system | 2017-02-08T21:53:29.000 |
| 4646 | 2018.A.00047.S | 1599 | Shock-induced chemistry in the CSEs of late-type stars: a pilot study | The circumstellar envelopes (CSEs) of stars in transition from the Asymptotic Giant Branch (AGB) to the Planetary nebula (PN) phase have proved to be dusty and molecule-rich. The onset and propagation of fast molecular outflows throughout the CSEs can affect the chemistry of the molecular gas, since shock propagation is able to remove molecules from dust grains (i.e., grain sputtering) returning them to the gas phase as well as break apart molecules that are already in gaseous form, thus providing free atoms to create new molecules in the post-shock region. While most of the current knowledge in terms of line emission from evolved stars is based on spectral surveys of IRC+10216 and IK Tau, our scope is to provide the scientific community with a set of data that can pave the way for further detailed studies at higher spectral and angular resolution. We propose to perform a spectral survey in Band 3 of AGB and post-AGB stars, spanning the 85-116 GHz range. This will allow us to investigate the presence of lines found in shocked material as well as typical lines of molecular CSEs, such as CO, SiO, CS, OH, and H2O. | Asymptotic Giant Branch (AGB) stars, Post-AGB stars | Stars and stellar evolution | 2019-08-19T00:00:00.000 |
| 4647 | 2015.1.00410.S | 6 | Molecular outflows, accreting spirals and a circumbinary disk in a young binary system | Recent results of exo-planetary surveys have revealed that planets can orbit and survive around binary stars. This suggests that there are some fraction of young binary systems which possess massive circumbinary (CB) disks are in the midst of planet formation. Among the few known binary systems where the CB disks have been detected, the UY Aurigae system appears very active in accretion. Signs of accreting streamers connecting the CB disk and the stars and molecular outflows have been detected. We propose to study this system on how material accretes toward the CB disk and toward the circumstellar disks. We request two science goals: 1) in Band 7 observations of the CO isotopologues and continuum at 0.8 mm with 1.0 resolution in the C36-2 configuration to determine the properties of the CB disk and 2) in Band 6 observations of the 1.3 mm continuum, CO isotopologues and SO lines with 0.2 resolution in the C36-6 configuration to resolve the CS disks in continuum and in CO lines. This study will constrain the angular momentum transfer between the CB and CS disks, providing information on how disks around binary systems form and evolve towards planet formation. | Disks around low-mass stars | Disks and planet formation | 2018-03-09T04:15:31.000 |
| 4648 | 2018.1.00659.L | 2702 | ATOMIUM: ALMA Tracing the Origins of Molecules In dUst-forming oxygen-rich M-type stars | Over 200 molecules and 15 dust species have been detected in the ISM, stellar winds, exoplanets, supernovae, active galactic nuclei etc. One of the most fundamental questions in astrophysics deals with the phase transition from simple molecules to larger gas-phase clusters and eventually dust grains. The outflows of evolved stars are the best laboratories to answer this pivotal question due to their rich chemistry and relatively simple dynamical structure. With this Large Program we aim to establish the dominant physical and chemical processes in the winds of oxygen-rich evolved stars over a range of stellar masses, pulsation behaviours, mass-loss rates, and evolutionary phases. The goal is to unravel the phase transition from gas-phase to dust species, pinpoint the chemical pathways, map the morphological structure, and study the interplay between dynamical and chemical phenomena. The legacy will be (1) the plethora of ground-breaking results in the field of evolved stars, astrochemistry, and the chemical life cycle of the ISM; and (2) a foundation to better understand astrochemical processes in a range of research fields, from proto-planetary disks to luminous infrared galaxies. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2020-10-10T12:43:12.000 |
| 4649 | 2019.1.00790.S | 46 | Dense molecular gas as a test for star formation laws at z=2-3 | There is mounting evidence for a more efficient mode of star formation in galaxies at z~2 compared to the present day. We seek to verify this result with dense gas observations of galaxies. Gravitational lensing offers the unique opportunity to detect HCN in z~2 galaxies with normal star formation rates (SFR), as HCN is otherwise too faint to be detected in these galaxies even with ALMA. First results from our pilot Cycle 5 program show that their HCN content is indeed a good indicator of their SFR. We propose to complete the project by observing HCN in 4 additional galaxies, in order to probe the star formation law over two orders-of-magnitude of stellar mass. Combined with the rich ancillary data of the targets, we will (1) test whether the L_HCN-L_IR linear relation holds at z~2; (2) measure the dense gas fraction (L'_HCN/L'_CO) in normal galaxies at z~2. The proposed observations will directly constrain whether the mode of star formation varies with cosmic time and stellar mass: do z~2 galaxies behave like local starbursts or spirals, in terms of star formation efficiency and dense gas fractions? Do galaxies follow the same star formation law across cosmic epochs? | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2021-02-07T17:03:22.000 |
| 4650 | 2023.1.01689.S | 0 | Resolving dust continuum in intrinsically-faint H-dropout ALMA galaxies behind lensing clusters | We propose to obtain ~0.2 arcsec resolution 1.2 mm dust-continuum images of five lensed (intrinsically faint) NIR-dark ALMA galaxies at z = 2 5. Recent ALMA deep observations uncover faint (sub)mm-selected galaxies and a fraction of them are known to be invisible even in the deepest HST/WFC3 (and even JWST/NIRCam) near-infrared images (i.e., H-band dropouts), but their nature remains elusive partly because their faintness hampers any further spectroscopic and high-resolution follow-up observations. The proposed sources are apparently bright thanks to significant magnification (mu = 5 9) and therefore provide ideal laboratory to investigate physical properties of intrinsically-faint dust-obscured galaxies. We will directly measure the sizes of dust emission to test the proposed scenarios on the origin(s) of near-infrared darkness, i.e., the compactness of dust and stellar distributions or disk inclination (i.e., galaxies seen in edge-on). Preliminary dust source size measurements of reconstructed source plane images using ~1 arcsec images already suggest a diversity of physical cause. Confirming it by ~0.2 arcsec resolution observations of more sources will be a logical step. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2025-07-05T14:02:36.000 |
| 4651 | 2015.1.00477.S | 34 | Mapping the extent and durability of dust in early-type galaxies detected with Herschel | Early-type galaxies were once thought to be simple systems, with a lack of cold interstellar medium, but are now known to harbour gas, dust and star formation in many cases. This may form the basis of discovering how they evolve into the elliptical and lenticular galaxies in the local Universe. This application aims to measure the distribution and survivability of dust and molecular gas in a small sample of early-type galaxies with dust detections from Herschel space telescope at unexpectedly high levels (>2 x 10^7 Msun), comparable to spirals of similar mass. Whilst Herschel detected these sources, ALMA will resolve their emission from dust and molecular gas, and we will be able to measure the kinematics in the molecular gas. Any asymmetries in the gas and dust will be revealed, indicating a merger origins for the dust. We will test the spatial coincidence of the dust emission with the gas and hence test if it is shrouded from sputtering. Using spatially resolved radiative transfer programmes we will measure dust opacity, given the dust extents. Expected dust heating from the stellar populations will be obtained from application of the radiative transfer modelling. | Merging and interacting galaxies, Early-type galaxies | Galaxy evolution | 2017-07-20T16:57:24.000 |
| 4652 | 2021.1.00418.S | 3 | ALPPS: a survey of polarization toward the youngest protostars in the Perseus molecular cloud | What is the role of the magnetic field in determining stellar multiplicity? Recent surveys of very young, Class 0 protostars in the Perseus star-forming region have shown that proto-binary sources fragment on two different size scales: wide (~1000 au separation) and close (<250 au separation). The interpretation of this result is that turbulent fragmentation is the dominant formation mechanism at scales >1000 au, whereas the fragmentation of circumbinary disks dominates at scales <250 au. We propose an 850 micron (Band 7) ALMA survey of dust polarization toward 38 of the brightest Class 0 protostars in the Perseus star-forming region in order to study the role of the magnetic field in the formation of this bimodal population of binary sources. Our proposed ALMA observations of the magnetic fields in our sample of protostars in Perseus -- combined with complementary archival observations of stellar multiplicity, dust polarization, and spectral lines toward the same sample of sources from the VLA, ALMA, and GBT -- will allow us to test whether the predicted results of these fragmentation paradigms are correct. | Low-mass star formation | ISM and star formation | 2024-10-03T13:33:42.000 |
| 4653 | 2017.1.00963.S | 175 | More than Star Formation: High-J CO SLEDs of High-z Galaxies | We propose to extend the CO spectral line energy distributions (SLEDs) for a sample of seven z>2 galaxies to high-J (J_upper >9). Observations of high-J CO lines in the HerCULES sample showed that many local U/LIRGs require XDR or shock heating of their molecular gas, indicating that AGN likely affect the conditions of the gas reservoirs that fuel their rapid star formation. Since a number of individual high-J lines have been observed in high-z starbursts, we aim to expand the sample of high-J CO lines in order to understand the prevalenace of AGN-driven XDR or shock heating of molecular gas in SMGs and AGN. Since most existing CO SLEDs are poorly sampled past the peak of the SLED, additional lines are required to characterize the gas physical conditions (density/ temperature/ radiation field strength) that gives rise to their high-J lines. Since AGN are suggested to play an important role in ending bursts of star formation in massive galaxies like SMGs, characterizing the drivers of high-excitation molecular gas is important for determining how AGN affect star formation, and thus galaxy evolution, in the early Universe. | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2019-06-15T15:23:53.000 |
| 4654 | 2017.1.01019.S | 17 | Feeding Gravitationally Unstable Disks: The kinematics of the Envelope Around L1448 IRS3B | ALMA Cycle 4 observations of the triple protostar system L1448 IRS3B have resolved spiral structure originating from an inner (~60 AU) binary with a third protostellar companion embedded within one of the arms. A wide companion (~1800 AU), IRS3A, was also captured with the observations, revealing its own spiral structure, but the major axis of the disk around IRS3A is orthogonal to the axis of the disk around IRS3B. Current observations have yet to fully characterize the kinematics of the surrounding envelope of this system, which is feeding material into the protostellar disk. It is currently unknown if this infall of material is what triggered the disk instability due to asymmetric mass loading unto the disk, dominating the formation of this disk. Thus, IRS3A+B are ideal targets to better understand the formation of the disks and spiral structures; one of the main avenues for such disks instabilities in the presence of an in-falling envelope. We propose ALMA observations of the bulk gas kinematics with N2H+, an excellent high-density gas tracer and seek to characterize the motion of the infalling gas and their influence on the formation of the disks. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2019-12-06T17:53:55.000 |
| 4655 | 2019.1.01729.S | 21 | Shocks and Star Formation across the Taffy system | The Taffy system was formed from the head-on collision of the galaxy pair UGC 12914/5. This strong interaction has created a 20 kpc-long massive and turbulent bridge of atomic and molecular gas. However, despite the huge amount of gas, there is a dearth of star formation (SF) in the intergalactic bridge compared to other interacting/merging systems. This becomes Taffy an ideal target to test the effects of dynamics (e.g., shocks/turbulence) on the SF process. Our previous multi-species (CO, HCN, HCO+, SiO) observations with the IRAM 30m telescope, at 6 position, suggest that the low dense gas fraction, combined with turbulent-induced shocks, are making the gas extremely inefficient to form stars. We propose to exploit the sensitivity and resolution provided by ALMA to resolve the emission of the dense and shocked gas all across the Taffy system. These data will tightly constrain the link between the physical/dynamical state of the gas and its SF, expanding the parameter space probed by normal star-forming galaxies and other interacting/merging systems with active SF. Such increment of the explored conditions would be essential to improve the current turbulence-regulated SF models. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2021-04-27T13:15:37.000 |
| 4656 | 2019.1.01132.S | 62 | Molecular gas in the starburst-driven superwind of NGC 1482 | Superwinds are some of the spectacular consequences of intense star formation activity in the central regions of galaxies. Recent observations have begun to reveal the morphology and energetics of such outflows in the local Universe. Despite the significance in regulating (suppressing/triggering) star formation, multi-line molecular data of starburst-driven winds acquired at high resolution are still limited to a small number of objects (e.g., NGC 253), which makes it difficult to understand the relation between outflows and their host galaxies. In this study, we propose to conduct the first sensitive, high-resolution imaging of molecular gas in the nearby starburst galaxy NGC 1482, which hosts a powerful biconical outflow detected in X-rays, H-alpha, and dust on kpc scale. The multi-line data of CO, CN, CS, and CH3OH will reveal the morphology, dynamics, and physical conditions (including shocks) of molecular gas in the outflow and its base in the galactic disk. We will test the cylindrical outflow model proposed to describe the multiphase outflows in starburst galaxies, that will provide valuable input information for modelling starburst-driven galactic winds. | Starbursts, star formation | Active galaxies | 2021-03-12T05:32:36.000 |
| 4657 | 2015.1.00727.S | 3 | Locating the origin of the radio jet in the blazars | We propose to measure the Faraday rotation measure (RM) of a BL Lac object W Comae robustly at a single 3-mm band for the first time among known blazars. Aim: Our aim is to probe the location of the radio core at 3mm by comparing with RMs of Fanaroff Riley 1 (FR1) radio galaxies measured in our previous studies, which are counterparts of BL Lac objects in the unification scheme of AGNs. Scientific impact: Proposed observation provides a new constraint on the location of the millimeter radio core in blazars, which has been one of the hottest issues on radio-loud AGNs. Detection or non-detection of RM in the proposed observation favor the nearside or farside scenario, respectively. In addition, W Comae is expected to have a similar intrinsic luminosity to the most well-studied FR1 radio galaxy M87. Proposed observations provide unique clues to unify the observational properties of the relativistic jets in radio galaxies and BL Lac objects. Why do we need ALMA?: We aim to request a 1-sigma sensitivity of 0.025 mJy/beam for the total intensity map. This can not be achieved with any other millimeter interferometers at 3 mm. Only ALMA can achieve our scientific goal. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2017-12-20T00:00:00.000 |
| 4658 | 2019.A.00019.S | 8 | Characterize the submm nature of host galaxies of a "quasar-quasar" pair at the cosmic dawn | We propose 0.5" resolution [CII] 158um line and rest-frame far-infrared continuum observations toward a newly discovered z = 6.05 low-luminosity unlensed "quasar-quasar" pair (separation ~ 12 kpc) by our on-going Subaru/HSC survey. With this only ~2hr investment, we can characterize star-formation rates, global gas distribution, dynamical masses, early co-evolution, and even ~10 kpc-scale reionization geometry around the system. From our optical data, we already captured hints of close interaction of these quasars. According to hydrodynamic simulations of galaxy-mergers, such interacting galaxies will coalesce to form a heavily dust-obscured starburst and an extremely luminous quasar such as discovered by past wide-field optical surveys. Hence, this quasar-quasar pair will provide a very unique laboratory to study the formation processes (or conditions) of luminous quasars (supermassive black holes), massive galaxies, and early co-evolution, at the cosmic dawn. The properties obtained here must be beneficial for planning efficient JWST Cycle 1 and ALMA Cycle 8 programs to investigate further details of this system. (The exact coordinate will be set in Phase2) | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2020-12-31T07:27:15.000 |
| 4659 | 2017.1.01176.S | 143 | Quiescence of quiescent galaxies at z~2 | There has been an enormous amount of progress in our understanding of massive quiescent galaxies at high redshifts (z~2). There are more than 20 spectroscopically confirmed quiescent galaxies with no strong emission lines. Recent discovery of quiescent galaxy at z=3.7 by Glazebrook et al. pushed the frontier of the field to higher redshifts. However, deep ALMA observation of the object revealed a dusty star forming component, posing a question on the quiescent nature of the galaxy. Also, recent stacking analysis of Herschel data suggests that many of the color-selected quiescent galaxies indeed have a lot of obscured star formation. Although the stacking method suffers significantly from blending effects, it is fair to say that we do not know that our current quiescent galaxies are truely quiescent. We here propose to observe 14 spectroscopically confirmed quiescent galaxies in band 6 in order to reveal the true nature of these apparently quiescent galaxies by probing their dust continuum. If our sample is significantly contaminated by dusty starforming galaxies, it will urge us to dratistically revise our current understanding of massive galaxies at high redshifts. | Galaxy structure & evolution | Galaxy evolution | 2020-03-04T12:19:16.000 |
| 4660 | 2022.1.00804.S | 3 | Gas kinematics and dust trapping in the only known circumtriple disk | The recent ALMA observations towards the large circumtriple disk GW Ori have resolved it into three dusty rings that are inclined with respect to each other and with respect to the orbital plane of the host stars. These rings are likely precessing. If they can form planets, it may explain why some planets are on oblique or retrograde orbits. We propose to perform dust polarization observations at Band 4 and 7, and perform high angular/velocity observations of the high excitation lines CO J=3-2 and HCN J=4-3 at Band 7. The main goals are (1) based on diagnosing dust self-scattering polarization and dust spectral indices to discern whether or not there is grown dust in the rings which is the precursor of planets, and (2) to hunt the unseen planets based on examining the planet-induced kinematic features (e.g., doppler flips or linewidth broadening). Moreover, this project will serve as another attempt to detect CO polarization which is a rather novel scientific case. Finally, the requested molecular line observations will help understand the global gas kinematics in much greater detail. This will be a unique opportunity to understand the so-called disk tearing mechanism. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2025-08-27T06:42:56.000 |
| 4661 | 2017.1.00091.S | 57 | Establishing a new laboratory to study early star formation : [CII] in a lower mass but very dusty galaxy at z~4.6 | We propose a Band 7 spectral sweep to detect [CII] and determine the spectroscopic redshift for a strongly-lensed galaxy at z~4.6. This galaxy, MACS0717_Az9, was detected in our AzTEC/LMT imaging of the Frontier Fields clusters. The optically-identified multiply-imaged counterpart has so far eluded spectrosopic confirmation in the ongoing optical campaigns, likely because of the high dust-obscuration that we discovered with AzTEC/LMT. With an intrinsic SFR of 19Msun/yr and an intrinsic stellar mass of 6.9e9Msun, this galaxy is one of very few normal galaxies that have been detected in dust continuum at z>4 and probes a new region of parameter space. As the highest redshift multiply-imaged source in this cluster, a spectroscopic redshift will be invaluable to constraining the lensing model at the level required for cosmography. Furthermore, establishing the spectroscopic redshift is the only way to enable further studies of spectral lines that probe the gas and dust properties in the normal galaxies that dominate the cosmic star formation at this early epoch. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2019-08-29T21:16:52.000 |
| 4662 | 2018.1.00197.S | 1016 | Surveying the Seeds of Star Formation: Starless Cores in Aquila | Starless cores represent the initial conditions for the next generation of stars. The degree of substructure in these cores is directly linked to core formation processes and stellar multiplicity. We have conducted ALMA surveys of starless cores in Chamaeleon I (Cycle 1), Ophiuchus (Cycle 2), and Orion B North (Cycle 3), finding evidence for both starless core fragmentation and hidden protostars. However, we have also shown that fragmentation is biased toward the most gravitationally unstable starless cores that are rare in the clouds targeted to date, thus our statistical constraints on starless core fragmentation remain poor. Here we extend our survey to the Aquila molecular cloud, targeting the 100 most unstable Aquila starless cores with Band 3 continuum and CO observations, increasing our total sample of unstable starless cores more than a factor of four. With these data we will fully determine the fraction of cores harboring hidden protostars, the timescales of fragmentation, and the role of turbulent fragmentation in the formation of multiple systems. This is a resubmission that seeks to complete partially observed projects from Cycles 4 and 5. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-07-09T02:08:30.000 |
| 4663 | 2017.1.00367.S | 141 | Establishing a timeline for the high-mass star-formation process | Studying the first stages of high-mass star formation is observationally demanding, because the entire early evolution takes place while the young stellar objects (YSOs) are deeply embedded in their parent cloud. Nevertheless, in recent years it has become possible to arrange high-mass star forming regions (HMSFRs) on a relative timeline. Yet, while statistically correct, this does not give any information on the actual age of individual YSOs. With the high resolution obtainable with ALMA and new chemo-dynamical models this situation is about to change. In cold and dense material molecules are locked onto grains, but are evaporated into the gas phase when the temperature exceeds a certain threshold, different for each species. When this happens the abundance will increase drastically. With the continued heating by the YSO this evaporation front will expand making it possible to order individual YSOs, as opposed to entire HMSFRs, on a relative timeline. To do this we want to observe selected species in HMSFRs in different evolutionary phases. Then, with the aid of chemo-dynamical models, we can link the size of the evaporation region and the luminosity of the YSO with an actual age. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2019-11-25T16:20:05.000 |
| 4664 | 2016.1.00010.S | 68 | Resolving GMCs using CO Absorption Toward Compact QSOs Directly Behind the MW Disk | We propose an absorption study of the internal structure of GMCs and molecular ISM in the Milky Way (MW) in CO, 13CO, and C18O J=1-0 and 2-1 transitions. ALMA can provide the highest spatial and velocity resolutions by utilizing two compact QSOs (<10 milliarcsec; <10-100AU at 1-10kpc) directly behind the MW mid-plane (|b|<0.2deg) and detecting the absorption at the sound speed resolution (0.2km/s) for the cold molecular gas. The lines-of-sight of these QSOs cut through ~10 GMCs across the MW, providing a good sample of typical GMCs in the MW. We will (1) detect the theoretically-predicted, yet unproven, smallest molecular structures within the ~10 GMCs across the MW, (2) measure the variations of gas column density, temperature, and CO-isotope ratios in the typical molecular ISM across the MW disk with unparalleled precision, and (3) search for the diffuse, extremely cold CO gas possibly not excited for emission, and thus potentially missed in the previous emission studies. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2018-01-20T16:43:06.000 |
| 4665 | 2016.1.00431.S | 18 | Properties of Molecular Gas and Dust in the Close Environment of a Long-duration Gamma-ray Burst | Long-duration gamma-ray bursts (GRBs) are thought to be originated from the explosions of massive stars, and accordingly they are expected to occur in molecular clouds. Previous studies of absorption in the spectra of GRB afterglows suggest a large gas reservoir in the GRB circumburst comparable with those found in GMCs. However, absorption studies only probes the line of sight to GRBs, and no measurement of molecular gas content in GMC scale has ever been done. We propose observations of CO and dust continuum emission in the host galaxy of GRB980425, the nearest GRB (36.1 Mpc). The host is the unique target because of its proximity, providing an opportunity to probe the environment around the GRB in 100 pc scale (with 0.59" angular resolution). The primary goal is to verify that a GRB actually occur in the environment of dense molecular gas. Our CO(1-0), CO(3-2), and dust emission observations will reveal the properties of molecular gas and dust (molecular gas content, excitation condition, distribution of molecular gas and dust, and velocity field) in the close environment around a GRB for the first time, allowing us to investigate the formation mechanism of a GRB progenitor. | Gamma Ray Bursts (GRB) | Cosmology | 2018-05-30T23:03:37.000 |
| 4666 | 2017.1.00820.S | 33 | ALMA Monitoring of Sgr A* coordinated with Spitzer & Chandra Space Observatories in July 2018 | We propose to use ALMA as part of an observing campaign led by Spitzer and Chandra for continuous monitoring of Sgr A* for two days in July 2018. Recent detection of flare emission from Sgr A* at 4.5 microns using Spitzer gives a fantastic opportunity to monitor Sgr A* continuously. Spitzer monitoring of Sgr~A* emission levels in the mid-IR is far superior to ground-based observations. Previous campaigns using mid-IR from the ground and space have never been able to monitor Sgr A* with such overlapping time coverage as proposed here. Simultaneous observations across the electromagnetic spectrum are essential to tie down models of Sgr A*'s activity, and that the submm represents a critical link between the IR and radio. The proposed measurements will confirm an absorption in submm wavelengths when there is a mid-IR flare and will establish the time delay relationship between submm and mid-IR flare emission. These will ultimately tell us about black hole accretion physics and will confirm that optically thin (mid-IR) and thick (submm) flare emission are physically associated with each other. This experiment requires a long ALMA observation to be successful. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-06-26T21:19:48.000 |
| 4667 | 2017.1.00226.S | 413 | The W43 complex: a case study for high-mass star formation | The current models explaining for the formation of high mass stars entail critical differences at the earliest stage of their formation. One predict low dynamic at large scale but a high degree of mico-turbulence or magnetic field to sustain the cores against gravity (core-collapse model by McKee & Tan 2002). The other one predict high level of dynamical features with accretion shocks (competitive accretion model by Bonnell & Bate 2006). During cycle 3, our team obtain crucial information of the magnetic field morphology over 7 of the most massive dense cores of our Galaxy (with masses ranging from 390 Msun to 3950 Msun within ~0.3pc). We computed the support offered by the magnetic field in the cores and found out it was not sufficient to sustain the cores against gravitational collapse. We now ask for gas dynamic information to derive the turbulent support (to confront with the core-collapse model) and accretion flow/shocks (to confront with the competitive accretion model). | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-07-23T09:48:22.000 |
| 4668 | 2019.A.00025.S | 5 | The ALMA view of the Proxima c planet candidate | The aim of this proposal is to obtain a second epoch ALMA image of Proxima Cen to confirm or refute the reality of a secondary 1.3mm source, displaced 1.2 arcsec (1.5 au at 1.3 pc) from the star. Among several other possibilities, it was noted that its flux density was consistent with that of a Saturn-like planetary ring system, and thus, that it could be tracing a yet unknown planet orbiting Proxima Cen. Now, independent evidence for a second planet, Proxima c, has been gathered. Radial velocities suggest a planet orbiting at 1.5 au, the same distance obtained from the ALMA image, and very recent VLT imaging suggests the presence of an optical/near-IR orbiting source coincident with the ALMA source. Given the large proper motion of the star Proxima Cen (4 arcsec/yr), and the orbital period of the planet (about 5.5 yr) the proposed second epoch ALMA observations will easily discriminate between a fake source, an unrelated background object, and material associated with planet Proxima c that is orbiting the star. | Exo-planets | Disks and planet formation | 2022-01-12T00:00:00.000 |
| 4669 | 2016.1.01072.S | 72 | Consuming and Expelling: Extreme Molecular Outflows in Massive Compact Galaxies | Powerful ejective feedback is a critical component of models of massive galaxy formation, essential for producing the observed galaxy population and the distribution of circumgalactic gas. However, the physical nature of this feedback is still poorly understood. While much previous work has focused on energy released by AGN, it is increasingly clear that powerful ejective feedback may also be produced by purely stellar processes. We have identified a remarkable sample of massive compact galaxies that have recently experienced a dense, feedback-limited starburst that has launched extreme-velocity, galactic-scale outflows. Our published CO observations for two of these systems show very short gas consumption timescales (t~10Myr) and molecular outflows that extend to at least 10 kpc. Here we propose to use the exquisite sensitivity of ALMA to dramatically enhance our understanding of molecular gas in these galaxies. With this systematic study, we will determine whether massive, compact star-forming galaxies commonly exhibit large-scale molecular outflows and short gas depletion times, the hallmarks of ejective feedback that can shut down star formation in massive galaxies. | Starburst galaxies | Active galaxies | 2018-03-21T17:16:20.000 |
| 4670 | 2015.1.01193.S | 10 | HCO as a precursor of astrobiological molecules | Glycolaldehyde (CH2OHCHO), the simplest of the monosaccharide sugars, and ethylene glycol ((CH2OH)2), the simplest aldose, has been proposed to play a central role in interstellar prebiotic chemistry. Since they are thought to be directly linked to the origin of life, it is crucial to investigate how they are formed in the universe, especially in star-forming regions, where stars and planetary systems are expected to form. The goal of this project is to observationally test the formation route to glycolaldehyde and ethylene glycol by studying its proposed progenitor, the formyl radical HCO, towards two different environments: the massive hot core G31.41+0.31 and the low-mas binary IRAS16293-2422. Our aim is to map at high angular resolution the spatial distribution of the 3 molecules to check if they arise (or not) from the same region. We will also compare the observed abundances of the different molecules with the predictions from our already developed chemical models, which will help us to unveil the most likely chemical route of glycolaldehyde and ethylene glycol formation. | High-mass star formation, Low-mass star formation | ISM and star formation | 2017-07-23T00:30:55.000 |
| 4671 | 2013.1.00686.T | 0 | The Distribution of Extended Source Species in a Bright Apparition TOO Comet | Certain molecules observed towards cometary atmospheres have a physical distribution that cannot be explained as direct sublimation from the nucleus or gas-phase chemistry within the coma. The extended source of these species is not known, though it is believed to be an organic mixture or degradation of dust. As part of a joint collaborative multiwavelength effort, we will conduct an observational survey of extended source species and their possible parent or related molecules in a target of opportunity comet. This study will image CO, H2CO, and CH3OH. These observations will help constrain the origin and extent of the distributed source for each species, the scalelength of the source, establish accurate molecular abundances, and provide insight into comet chemistry. These results will build off observations of these molecules in Comet C/202012 S1 (ISON) and C/2012 F6 (Lemmon) previously obtained with ALMA. The target of opportunity comet should have Q(H2O) ~ 1e29 s-1, and may be a new dynamical object or a known apparition undergoing an outburst event. | Solar system - Comets | Solar system | 2016-03-19T13:04:33.000 |
| 4672 | 2016.1.00788.S | 2 | Microflares in the Chromosphere with ALMA | ALMA offers a truly unique insight into the Sun by providing a linear thermometer into the chromosphere. These layers of the chromosphere are largely unstudied or have been muddled by line-of-sight effects common to optically thin measurements. Here we intend to use the advantages of ALMA in order to study one of the most readily available signatures of magnetic reconnection, microflares, in the chromosphere: the region through which the energy and plasma must flow to get into the corona. By observing the statistics of microflaring in two wavelengths, we will be able to better constrain the heights and dynamics of energy transfer in the chromosphere during magnetic reconnection. | The Sun, Transients | Sun | 2018-06-23T23:36:19.000 |
| 4673 | 2015.1.00846.S | 38 | The end and the beginning of episodic AGN triggering in IC 2520 | Galaxies comprising the bulk of the Hubble sequence are believed to form via multiple episodes of star formation and AGN. The duty cycle of individual episodes is however poorly understood. We have identified a galaxy, IC2520 at 17.8Mpc, that is an ideal template to study how episodes of galaxy assembly are triggered and quenched. It shows evidence for having recently completed a starburst and an AGN phase, from its classification as a shocked post-starburst galaxy and as a `Voorwerp'. However, it also shows evidence for a newly rejuvenated AGN, via resolved radio structure and a clear XMM detection. These properties mark IC2520 as being `caught between two phases'. We propose to measure the morphology and velocity structure of CO(2-1) in IC2520. We expect to see one large `old' CO outflow, potentially aligned with the voorwerp features, and one small `new' CO outflow, from the recently rejuvenated AGN. We will use the morphology of the CO in IC2520 to determine how episodic triggering affects molecular gas in Hubble sequence galaxies. Our overall aim to establish a detailed case study for episodic assembly of galaxies in the local Universe. | Starbursts, star formation, Spiral galaxies | Active galaxies | 2017-08-24T00:26:08.000 |
| 4674 | 2015.1.00805.S | 29 | Dissecting lopsided protoplanetary dust traps | Large-scale crescent-shaped continua imaged by ALMA in transition disks strongly suggest that azimuthal dust trapping is concentrating the larger grains. Indeed, thanks to ATCA and VLA observations we have discovered compact concentrations of cm-sized grains burried inside the larger-scale sub~mm emission in HD142527 and MWC758. With long-baseline resolutions in Cycle~3 we can 1- measure the key parameters responsible for the efficiency of dust trapping, 2- map the gas kinematics and so understand the origin of the pressure maxima where grains pile up, and 3- search for substructure in the dust trap maximum or deviations suggestive of on-going core-accretion. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2018-03-27T12:00:23.000 |
| 4675 | 2016.1.00460.S | 51 | Measuring vertical settling and radial drift of dust: A survey of young edge-on disks | We propose to observe a well-defined sample of Edge-On Disks to study the radial and vertical distribution of the dust. Scattered light images of edge-on disks like HH 30 have established what we think is typical for the shape and flaring of protoplanetary disks. However, these conclusions are correct only for the small grains, i.e. the near-IR scattering opacity carriers, but are very likely incorrect for the larger dust particles emitting at longer wavelengths. The large particles are expected to be distributed differently in particular because of dust settling, but so far we are still missing direct images that would reveal the vertical stratification of dust of all sizes in T Tauri disks. ALMA cycle-4 offers the perfect opportunity (resolution, sensitivity), and the edge-on geometry allows for direct conclusions beyond doubt. By comparing the gas distribution to the distributions of small and large dust grains, we can draw definite conclusions about the disk shape, and the settling and radial migration of solids with unprecedented details. All are key issues for a better understanding of the physical and chemical processes during the early stages of planet formation. | Disks around low-mass stars | Disks and planet formation | 2018-12-19T17:19:01.000 |
| 4676 | 2018.1.01617.T | 70 | ALMA Follow-Up of NS-NS/NS-BH mergers from LIGO/Virgo Observing Run 3 | The first direct detection of gravitational waves from a binary neutron star merger led to the discovery of an electromagnetic counterpart, ushering in the era of multi-messenger astronomy. The GW data can shed light on the nature of compact object mergers, providing sensitive tests of General Relativity and insight into the neutron star equation of state. However, these goals can only be achieved via the joint detection of EM counterparts, which provide the necessary astrophysical context. Here we propose ALMA observations of up to three new GW events containing a neutron star during LIGO/Virgo Observing Run 3 (Dec 2018-Dec 2019). We will trigger ALMA immediately following the identification of an EM counterpart to search for and characterize relativistic outflows. ALMA observations are critical for breaking model degeneracies inherent to X-ray/cm data, and will delineate the early stages of the outflow when the emission is self-absorbed at cm wavelengths. These observations will pave the way for characterizations of non-thermal emission from GW sources, providing the first ever millimeter detections of GW counterparts. | Transients | Stars and stellar evolution | 2020-12-18T01:44:07.000 |
| 4677 | 2019.1.00332.S | 20 | First evidence for mm-wave microlensing in a strongly lensed quasar | We request ALMA follow-up of a strongly lensed radio-quiet quasar RXJ11311231, which shows a surprisingly large fluxratio anomaly in ALMA 2015 observations. This is in stark contrast with the general assumption that mm-wave emission in strongly lensed quasars originates from a dusty torus: instead, the most direct interpretation is that the mm-wave emission originates in the AGN corona, with an expected size of <0.01 pc. While mm-wave emission associated with AGN corona has been observed in nearby quasars, its size could be inferred only indirectly. For ~2.6 hours of Band 4 time, the requested two-epoch observations - in combination with optical monitoring - will unambiguosly determine the nature of the mm-wave flux-ratio anomaly in RXJ1131 (microlensing vs. millilensing and extremely time-variable source) and provide the first direct measurement of the AGN mm-wave corona size. | High-z Active Galactic Nuclei (AGN), Gravitational lenses | Active galaxies | 2021-06-25T19:00:45.000 |
| 4678 | 2021.1.01461.S | 3 | Have large-scale magnetic fields been formed in galaxies by z=2.6? | We seek to obtain the first detection of polarized thermal dust emission in a star-forming galaxy in the early Universe. The target is an exceptionally bright gravitationally lensed submillimetre source known as 9io9 (z=2.6). Its high flux density in the millimetre makes detection of even modest (1%) thermal dust polarization fractions achievable with ALMA. The presence of polarized dust emission would indicate the existence of a large-scale magnetic field in a star-forming galaxy seen just a few Gyr after the Big Bang. Not only would this pave the way for further investigation of the magnetic field properties of early galaxies (and thus providing unique insight into the conditions of the interstellar medium, such as the role of turbulence in regulating star formation), it would place important empirical constraints on the epoch of formation of galaxy-wide magnetic fields in galaxies, with ISM turbulence on small scales expected to play an important role in generating large-scale fields through the dynamo effect. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2023-08-04T12:27:49.000 |
| 4679 | 2012.1.00268.S | 0 | Solving the Faint Young Sun Paradox wit ALMA | There is clear geologic evidence for a mild, warm climate in the early history of Earth and Mars, but standard solar models imply that the Sun's bolometric luminosity 4.6 Gyr ago was only 70% the present level. The surfaces of both planets should therefore have been entirely frozen. This long-debated "Faint Young Sun Paradox" would be solved at once if the young Sun had been somewhat brighter than standard models predict, having been slightly (by a few percent) more massive than today. The implied enhanced mass loss in the early Sun could be easily detected by ALMA, by measuring thermal free-free emission from the magnetized wind of a young solar-like star. We will observe a nearby, young solar analog (chi1 Ori) for which we have already obtained low-frequency radio observations with the JVLA. Only the spectral shape observed over ~an order of magnitude in frequency can unambiguously identify an ionized-wind contribution for which we have made appropriate model calculations. Because the wind spectrum increases with frequency while other contributions are very weak at millimeter wavelengths, ALMA will crucially identify a wind contribution or set sensitive upper limits, thus confirming or refuting the ``Bright Young Sun'' hypothesis. | Main sequence stars | Stars and stellar evolution | 2014-12-20T00:00:00.000 |
| 4680 | 2023.1.01382.S | 0 | A quest for S-bearing refractory species | Sulphur is the tenth most abundant element and one of the six fundamental to life. Despite its relevance, there is an apparent lack of S-bearing species detected in the ISM: while the observed sulphur in diffuse gas accounts for its total cosmic abundance, about 90% remains unseen in the dense gas. It has been suggested that sulphur may get locked in refractory material during the formation of dense clouds, and could remain in this way during most of the star formation process. The study of refractory material has been limited in the past, due to the special conditions that are required for these species to be released into the gas-phase. The recent detection of the refractory molecules NaCl and KCl in nine disks around massive young stellar objects has opened a new door to search for other refractory species, in particular those containing sulphur. In this proposal, we will search for S-bearing refractory species using the high resolution and sensitivity enabled by ALMA. Their detection would be the first in the ISM, and would help to evaluate the amount of sulphur that is locked in refractory material. Even non-detections would set stringent upper limits to their abundances. | Astrochemistry | ISM and star formation | 2025-01-03T23:06:53.000 |
| 4681 | 2021.1.00860.T | 37 | Episodic impact of energetic EXor outbursts on the circumstellar environment | The spectacular luminosity outbursts of the EX Lupi-type (EXor) pre-main sequence objects are driven by a 10-100x rise of the accretion rate from the circumstellar disk onto the star. They affect the properties of the inner disk via the enhanced radiation field, an essential process to be considered in the inner disk evolution and initial conditions for terrestrial planets. The outbursts are unpredictable, typically last a few months, thus a normal ALMA proposal cannot be used to study them. Here we propose a Target of Opportunity program to observe an energetic EXor outburst, if such an outburst is discovered during Cycle 8, close in time to the peak brightness, and obtain the first picture of the molecular content of an EXor disk in the high state. We will determine basic stellar and disk parameters, and compare the molecular lines with our time-dependent chemical model. We foresee to submit a follow-up normal ALMA proposal in the post-outburst period, to reveal the long-term chemical evolution and constrain our chemical model. Our project will open up the way to learn if outbursts produce or destroy certain key molecules in any disk whose thermal history is known. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-03-23T11:34:59.000 |
| 4682 | 2017.1.00825.S | 33 | Characterizing the Brown Dwarf Orbiting Interior to the Debris Ring around HD 206893 | Directly imaged companions orbiting within directly imaged debris rings provide a rare and valuable opportunity to place dynamical constraints on the mass and orbit of the companion. HD 206893 is only the second known system to host a directly imaged brown dwarf companion orbiting interior to a debris ring. The outer radius of the debris disk has been marginally resolved by Herschel, but the inner radius, eccentricity, inclination, and degree of axisymmetry of the disk are still unknown. Here we propose to spatially resolve the full debris ring to measure its properties and derive dynamical constraints on the mass and orbit of the brown dwarf companion, which will also provide insight into its formation mechaism. Since the masses of directly imaged brown dwarfs are derived from largely uncalibrated models of their photometric and spectroscopic properties, a dynamical constraint from the object's interaction with the debris ring will have significant impact on our broader understanding of brown dwarfs. | Debris disks | Disks and planet formation | 2019-10-15T14:04:14.000 |
| 4683 | 2016.1.01439.S | 17 | Imaging the dust destruction cavity around the magnetar SGR 1900+14 | Magnetars are a small class of strongly magnetized pulsars emitting extremely powerful X/gamma-ray flares on several timescales. Magnetars' giant flares second in energetics, in our Galaxy, only supernova explosions: an energy of 1e45-1e47 erg is emitted in a few minutes. An infrared elliptical ring has been discovered by Spitzer surrounding the magnetar SGR1900+14, one of the three objects that ever showed a giant flare (occurred in August 1998), and which is hosted by a massive star cluster. The most probable interpretation is a dust-free cavity produced in the magnetar environment by the giant flare via different dust destruction processes, embedded in a hot dust cloud illuminated continuously by close-by massive stars. We performed 3D dust radiative transfer simulations to constrain the nature of this IR ring and its internal cavity. We ask for 3.5 hours of ALMA observation at 345 GHz to image part of this unique dust ring its the internal cavity to reveal the true origin of the elliptical ring, the dust mass involved, and have the potential to infer for the first time the anisotropy and energetic of a magnetar giant flare. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2018-05-30T06:15:38.000 |
| 4684 | 2018.1.00668.S | 781 | HO2 and H2O2 in -Ophiuchi A: a clue for the missing O2 in Molecular Clouds? | The O2 molecule has been detected in very few interstellar objects, the scarcity of detections has been a challenge for modern astrochemical models. Surprisingly, O2 has also been detected in the coma of comet 67P, this O2 could be primordial trapped into Ice during the protoplanetary disk formation. Among the scarce detection, O2 has been detected in the SM1 core of the -Ophiuchi A molecular cloud in conjunction with HO2 and H2O2. We propose to observe HO2, H2O2, NO, SO and SO2 with both high and low spatial resolutions in order to constrain the emission region of these molecules and to explain the origin of O2. The presence of H2O2 and HO2 in the extended cold envelope would suggest that H2O2 and HO2 formed on Ice are efficiently desorbed through non-thermal processes. In that case O2 should be produced through gas-phase reaction and NO and SO will act as O2 proxies. If H2O2 is detected in the warm inner core means that H2O2 thermal desorption is only partly destructive (leading to HO2 and O2) and HO2 will be used as a proxy of the amount of O2 produced through thermal destructive desorption of H2O2. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2020-07-29T09:54:12.000 |
| 4685 | 2016.1.00288.S | 204 | Tracing the outflows from disks around O-type (proto)stars | Current theories for the formation of the most massive stars (i.e. >20Msun) require massive, dense disks and high mass accretion rates to overcome radiation pressure and ionising radiation. However, to date only one (Keplerian) disk has been detected around an O-type protostar. To quantify the frequency and properties of disks around O-type protostars, we observed 6 candidates using ALMA at 0.2" resolution in a number of molecular species around 220GHz. Preliminary analysis shows clear velocity gradients in several sources, but a lack of existing large-scale observations means that the direction of the outflows are uncertain based on the ALMA data of SiO (5-4) and 13CO(2-1) alone. Establishing the outflow direction is important for identifying whether the disk and outflow within these systems are perpendicular, and hence rule out the possibility of the velocity gradients tracing, e.g., expansion rather than rotation. We therefore propose to map these 6 sources with ACA+TP to complement our Cycle 2 ALMA data and thus recover the extended SiO and 13CO emission resolved out in our ALMA maps. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2018-04-05T00:14:55.000 |
| 4686 | 2016.1.01601.S | 0 | Understanding Turbulent Ambipolar Diffusion and Core Field Morphologies in a Filament Forming Massive Star | Turbulence and magnetic field are ubiquitous in molecular clouds and are believed to be the most important forces that regulate star formation. At small scales, turbulent ambipolar diffusion (TAD, the decoupling of neutrals from magnetic fields and plasma) should become inevitable based on the MHD equations (Li & Houde 2008). The possible signature of TAD is the difference in linewidth between ions and neutrals (Li & Houde 2008 and Li et al. 2010). Our recent ASTE observation has demonstrated the positive correlation between the linewidth difference and B-field strength, reinforcing the validity of the theory of TAD. We forsee the capability of measuring B-field with this novel method. The ALMA observation serve as an important step to validating this idea. At the same time, we want to study how well the core B-field inherited the B-field in the filaments. The thermal dust polarization will tell us to what extent the large scale B-field dictates the formation of massive star in this NGC6334 filament. | High-mass star formation | ISM and star formation | 2020-03-07T00:45:57.000 |
| 4687 | 2017.1.00280.S | 253 | A Direct Test of the Possible Connection Between Fast Radio Bursts and Superluminous Supernovae | The first precise localization of a fast radio burst (FRB121102) led to two unexpected results: (i) a low metallicity dwarf host galaxy, and (ii) a spatially coincident quiescent radio counterpart. The host galaxy is identical to the hosts of hydrogen-poor superluminous supernovae (SLSNe), a rare type of core-collapse SNe powered by magnetars, while the quiescent radio source is a nebula associated with the FRB. In a recent paper we argued that these results indicate that FRB121102 is powered by a millisecond magnetar born in a SLSN explosion ~30 years ago. A strong prediction of this model is that known SLSNe that are a few years old should also exhibit nebulae, but with a peak in the mm-band. Here we propose to carry out the first such search, targeting a complete sample of all SLSNe (18 sources) that are >1.5 years old, located at z<0.5, and are visible to ALMA; these cuts lead to an expected flux density of >0.1 mJy at 100 GHz. Detections of associated nebulae will have profound implications for our understanding of both FRBs and SLSNe, while non-detections will invalidate our proposed model. We will couple the ALMA results to our modeling of the optical/UV data of the SLSNe. | Pulsars and neutron stars, Transients | Stars and stellar evolution | 2019-01-24T01:25:19.000 |
| 4688 | 2023.1.01430.S | 0 | Revealing internal structure and physical condition of the extremely young protostellar jets | While protostellar jets play a critical role in the star formation process to remove the excess angular momentum from the molecular core and facilitate mass accretion process onto the central stars, detailed observational studies are still very limited in number. Here, we proposed to make high angular resolution (~0.15 arcsec corresponds to ~60au) and sensitive ALMA observations toward two unique (i.e., the two youngest) molecular jets, MMS 1 and MMS 6, recently discovered in the OMC-3 region. We use various molecular and atomic lines (SiO, CH3OH, H2CO, SO, SO2, HCN, and CI) to cover the multi-transitions and their isotopologies. With this, we spatially resolve the internal structure of the protostellar jets and determine physical properties (e.g., temperature, colum density). We also compare gas spatial distribution with the resolution sufficient to resolve minor axis of the jets and discuss the fundamental physics of the protostellar jets such as how the neutral jets possily interact with surrounding molecular jets. | Outflows, jets and ionized winds | ISM and star formation | 2025-02-07T19:30:14.000 |
| 4689 | 2013.1.00103.S | 8 | Molecular gas in low-metallicity extreme starburst galaxies | When trying to understand the process of star formation in starburst galaxies, the cold gas content of the ISM is of fundamental importance. Such studies at high redshift are especially interesting since the mode of star formation in such galaxies appear distinct, with typical star formation rates and surface densities far surpassing normal galaxies at z~0. However, the conversion factor alpha_CO is still under debate – especially at low metallicities. Lyman break analogs (LBAs) offer a great opportunity to study this problem at lower redshift (z~0.2). They have a lower metal content than galaxies with similar masses at z=0.2, and average gas surface densities >1000 M_sun/pc2, serving as proxies for star-forming galaxies at earlier epochs. Here we propose to observe 4 galaxies of lower metallicity down to ~10% of the typical luminosity of star-forming galaxies at redshift z~2; covering two orders of magnitude in mass, we will test whether there is indication of lower CO luminosities and hence different alpha_CO values for low-metallicity LBAs. This dataset will also provide an excellent comparison parameter for high-redshift observations, one of the main scientific goals of ALMA. | Starbursts, star formation, Dwarf/metal-poor galaxies | Active galaxies | 2016-03-10T13:55:01.000 |
| 4690 | 2022.1.00495.S | 11 | Isotopic constraints on the IMF in the most extreme star-forming environments in the Universe | The small handful of known proto-cluster cores are the most extreme known star-forming environments in the Universe. Their very existence poses a serious challenge for galaxy formation models, in which no such structures are formed. We aim here to solve an intriguing, inter-related puzzle, which has far-reaching consequences. In each proto-cluster core we see a dozen intense yet ephemeral (~100 Myr) dusty starbursts, spanning distances that preclude mutual triggering. Using 13CO/C18O to trace their star formation history, being sensitive to their stellar IMF, and using [CI](1-0) as the most effective tracer of the molecular gas, we will determine whether these uniquely multiplexed starbursts are made possible by a lower rate of star formation, or by having considerably more gas to digest. 13CO/C18O/CI can be observed simultaneously in the two most extreme known proto-cluster cores: DRC and SPT2349-56, both at z=>4. With one deep ALMA observation of each cluster, we will answer our puzzle, providing a crucial benchmark for the cosmological evolution of the IMF. | Sub-mm Galaxies (SMG), Galaxy Clusters | Galaxy evolution | 2025-01-23T14:58:57.000 |
| 4691 | 2018.1.00517.S | 42 | WISDOM: Supermassive Black Hole Mass Measurements for Nearby Spiral Galaxies using Molecular Gas | Black holes are thought to play an essential role in galaxy evolution, leading to the various known correlations between the mass of the supermassive black hole (SMBH) and host galaxy properties (e.g. M-sigma relation, where sigma is the central stellar velocity dispersion). These correlations are however based on a relatively small number of measurements and a handful of methods, each with many limitations and selection biases. Recent works on dynamical SMBH mass measurements using molecular gas kinematics, including our own, now open the possibility to drastically increase the number and most importantly the variety of galaxies with an accurate SMBH mass measurement. Here, we therefore propose to measure the SMBH mass in 7 spiral galaxies, that fill the particularly poorly-populated but crucial low-mass region of the M-sigma relation. We already have incomplete datasets from previous cycles, and now request the missing data to complete our measurements and in turn overcome the substantial biases toward early-type galaxies currently present in the M-sigma relation. | Active Galactic Nuclei (AGN)/Quasars (QSO), Spiral galaxies | Active galaxies | 2022-11-12T22:30:00.000 |
| 4692 | 2021.2.00091.S | 11 | Mapping the Unique Dwarf Galaxies in the Local Group (MUDGILG) | We propose to observe and fully map the CO(2-1) line in two of the most metal-poor, star-forming dwarf galaxies in the Local Group -- IC 1613 and NGC 6822. These would be the first wide-field, high-resolution CO maps of these two galaxies. With only a handful of actively star-forming dwarf galaxies in the Local Group, IC 1613 and NGC 6822 are essential targets to understand the impact of metallicity on the interstellar medium (ISM). Despite its proximity, NGC 6822 has been observed relatively little with ALMA, while IC 1613 has not been observed at all with ALMA. The high sensitivity and large field of view of the ACA will allow us to create the first ever wide-field CO maps of these galaxies, with spatial and kinematic resolution capable of identifying the structure in individual molecular clouds. The proposed observations would enable a rigorous investigation of the properties of the low-metallicity, CO-bright molecular gas in these unique galaxies and would be compared with other tracers of the ISM and star formation, particularly VLA observations of HI, H-alpha imaging to trace recent star formation, and stellar populations characterized by Hubble. | Dwarf/metal-poor galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2023-12-21T17:32:13.000 |
| 4693 | 2023.1.00629.S | 0 | Hot or Cold: the constraint to dust temperatures for proper understanding of the obscured star formations | The fraction of dust-obscured star formation activities is critical to understand the whole picture of the Universe but remains poorly constrained, especially at z>5. While the dust temperature (Tdust) is essential to estimate the infrared luminosities (LIR) and the star formation rate (SFR), high redshift galaxies often exhibit considerable uncertainties in Tdust such as ~40K due to the lack of observations near the peak of dust thermal emission. As these uncertainties could lead to ~1dex uncertain estimates of the obscured star formation activities, accurate Tdust measurement is quite critical to gain a proper view of the obscured star formation. Here we propose ALMA Band-9 dust continuum observations toward five z>5 normal star-forming galaxies that exhibit large uncertainty in dust temperatures (205, the proposed observations enable us to obtain a significantly large number of galaxies with accurate measurement of Tdust and to establish an important benchmark to estimate the obscured star formation activities. | Galaxy structure & evolution | Galaxy evolution | 2025-11-15T13:11:42.000 |
| 4694 | 2018.1.00596.S | 57 | Are GMCs Real? Searching for the physical objects in a multiscale ISM | We propose fully-sampled observations of 12CO/13CO/C18O(2-1) of a 5 kpc-square box in NGC253, probing scales from 5 pc to 5000 pc. These observations will allow us to search for the signatures of bound molecular clouds in the ISM on a wide range of scales around the canonical cloud size of 50 pc. Identifying such a preferred scale will prove the view that Giant Molecular Clouds are well defined entities, but the lack of such a scale would support the view that what we observe as GMCs are just part of a larger hierarchical ISM and should not be regarded as real objects. We will use a dendrogram-based measure of the gravitational binding on a full range of scales to isolate this signature. We will also measure the properties of turbulence and angular momentum using techniques drawn from the literature. The observations will join a small number of complementary, archival data sets of sufficient quality for multiscale analysis. This will enable a robust, three-dimensional view of the molecular ISM. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2020-01-08T19:04:48.000 |
| 4695 | 2016.1.01240.S | 68 | ALMA opens a new window on the z>6 Universe | Measuring redshift of faint star forming galaxies becomes increasingly difficult as we approach the reionization epoch, because the Lyalpha emission is increasingly quenched by neutral hydrogen, and alternative redshift indicators (UV absorption lines, metal lines etc) are not within the reach of current capabilities. The use of [CII] line as a redshift indicator in the reionization epoch is still debated since at z>7 no clear detections have been obtained, while at z<6 galaxies seem to follow the same SFR-[CII] relation as metal pool local systems. The goal of this proposal is to observe a small sample of galaxies up to z=6.36, to detect the [CII]158micron emission and establish the [CII]-SFR relation immediately before reionization. By targeting galaxies without Lyalpha emission, which are probably the dominant population in the reionization epoch, we will show that ALMA can be efficiently used to measure redshifts for these star forming galaxies. The [CII] line is also a direct probe of star formation rate since it is not sensitive to dust obscuration: it can therefore provide key information on the nature of these sources and on the global SFRD | Lyman Break Galaxies (LBG) | Galaxy evolution | 2018-04-11T19:12:56.000 |
| 4696 | 2022.1.00070.S | 0 | Unveiling Planet Formation in the Disk around a Candidate Substellar Object J162656.43-243301.5 | Understanding planet formation in a wide mass range of the central object is an important astrophysical issue. We propose to observe a possible substellar (Teff = 1000-2000 K) object in the Oph-C region, J162656.43-243301.5, in the 12CO/13CO (2-1) and 1.3-mm dust-continuum emission. The SED of J162656 shows two peaks at 5.8 and 70 micron and a dip at 24 micron, i.e., signature of the transition disk. The ALMA Cycle 3 archival data of J162656 reveal a compact (r~< 20 au) dusty disk at 1.3 mm, as well as velocity gradients in the 12CO/13CO emission along the major axis of the dusty disk. With the higher-resolution, follow-up Cycle 9 observations, we aim to 1) unveil the sign of the planet formation in the disk, such an a gap / ring structure, in the 1.3-mm dust emission; 2) reveal the Keplerian rotation profile and measure the dynamical mass of the central object in the CO isotopologue lines; 3) study the mass of the planet from the gap structure, temperature and density profiles and gas depletion in the disk. We will compare these results to those around solar-type YSOs, and study planet formation around substellar and stellar objects. | Disks around low-mass stars | Disks and planet formation | 2025-01-04T18:44:23.000 |
| 4697 | 2022.1.00761.S | 0 | Harvesting a golden opportunity to trace the cold intracluster medium at z=2 | The intracluster medium (ICM) in high-z clusters is expected to be inherently multiphase. Simulations predict significant interplay between cold gas in the ICM and galaxies, connected to crucial processes like feedback, in-situ cooling and accretion. Observations reveal X-ray emitting gas, as well as cooler (10^4K), ionised phases through Ly-alpha. However, Lya-emitting gas is likely a small fraction of the cold gas phase. We are currently unable to constrain the total cold gas in the ICM (and therefore HI+H2), due to lack of emission in this regime, preventing critical tests of structure formation. We aim to constrain the cold gas, and its nature, in the ICM of a galaxy cluster at z=2. Cluster halos are too rare to coincide with submm-bright background QSOs, but by extreme luck there is a submm-bright galaxy behind the cluster, <100kpc in projection from the center, well within the virial radius. This is a unique chance to use OH+ absorption to probe the cold (100K) ICM, tracing outflowing and turbulent gas. This will reveal the physical conditions of the gas, and through modeling will place constraints on the HI and H2 content of the ICM at z=2, a huge advance in the field. | Galaxy groups and clusters | Cosmology | 2025-10-12T17:17:25.000 |
| 4698 | 2023.1.01481.S | 0 | Do Unusually Cold Submillimeter Galaxies Exist? | Luminous dusty starburst galaxies selected at submillimeter wavelength show a remarkably narrow range in dust temperatures of about a factor of 2, which are primarily due to differences in their star formation rate surface density, and hence, the density of massive stars heating the dust. Potential trends with redshift have been discussed as a secondary possibility, but it remains unclear if these can be cleanly separated from the selection functions of existing samples. For these reasons, the few known outliers from the general trends are particularly interesting to understand if multiple processes are at play. We have recently serendipitously discovered that a major outlier from a sample of >80 sources, identified as a z=2.0 galaxy with a Tdust of only 21K in the literature, may have been misidentified, and rather is a z=5.0 source with a "normal" Tdust. Given the apparently contradictory findings from different ALMA studies of this source, we here ask for a 25min integration with the ACA on the [CII] 158um line to independently confirm our findings. This will be important to clean up the debate with respect to the existence of unusually cold dusty starbursts in the literature. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-12-25T05:23:54.000 |
| 4699 | 2017.1.00712.S | 39 | Size Distribution of Dust Grains in the Young Edge-On Protostellar Disk of HH 212 | Our recent ALMA observations at ~ 8 AU (~0.02") resolution have resolved the young edge-on protostellar disk in HH 212, not only in the equatorial plane but also in the vertical direction for the first time at submillimeter wavelength. This opens up a new window to study the grain size not only at different radii but also at different heights, and thus the grain growth in the early phase of star formation. Here we propose to follow up to map the disk in 2 other frequency bands in order to determine the grain size distribution in the disk, in particular for the large grains with submillimeter to millimeter size. The proposed observations will provide the first data to probe the grain growth in the earliest phase of star formation and provide the initial stage for the dust settling seen in the later phase of star formation. | Low-mass star formation | ISM and star formation | 2019-01-30T00:19:34.000 |
| 4700 | 2012.1.00989.S | 0 | A Circumplanetary Disk in the FW Tauri System | Over the past seven years, direct imaging surveys for extrasolar planets have discovered a small but significant number of planetary-mass companions (PMCs) at separations >50 AU from their host stars. These wide companions pose a significant challenge to models of planet formation, and it is still unclear whether they should be regarding as brown dwarfs (forming via “scaled down” binary formation) or as planets (forming via “very wide” planet formation). We have identified a PMC orbiting the WTTS FW Tau that appears to be vigorously accreting from a circum(planetary?) disk, based on an extremely luminous blue optical excess and very high Halpha line flux. The accretion rate is higher than for any free-floating brown dwarf, casting doubt on parallels with brown dwarf formation. However, it is unclear whether this high accretion rate indicates a high disk mass, or simply a transient phase of enhanced accretion. The SMA detected a 4 sigma excess for FW Tau at 850 microns, but lacked the resolution to determine whether this excess coincides with the position of the primary or the companion. We therefore propose to use ALMA for 30 minutes to localize the source of the 850 μm flux; this observation will yield a circumplanetary disk detection limit of M > 0.03 MJup (5 sigma), even if 85% of the total dust mass is still associated with the (non-accreting) primary. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2015-04-29T15:50:01.000 |
| 4701 | 2022.1.00487.T | 20 | Episodic impact of energetic EXor outbursts on the circumstellar environment | The spectacular luminosity outbursts of the EX Lupi-type (EXor) pre-main sequence objects are driven by a 10-100x rise of the accretion rate from the circumstellar disk onto the star. They affect the properties of the inner disk via the enhanced radiation field, an essential process to be considered in the inner disk evolution and initial conditions for terrestrial planets. The outbursts are unpredictable, typically last a few months, thus a normal ALMA proposal cannot be used to study them. Here we propose a Target of Opportunity program to observe an energetic EXor outburst, if such an outburst is discovered during Cycle 8, close in time to the peak brightness, and obtain the first picture of the molecular content of an EXor disk in the high state. We will determine basic stellar and disk parameters, and compare the molecular lines with our time-dependent chemical model. We foresee to submit a follow-up normal ALMA proposal in the post-outburst period, to reveal the long-term chemical evolution and constrain our chemical model. Our project will open up the way to learn if outbursts produce or destroy certain key molecules in any disk whose thermal history is known. | Low-mass star formation, Astrochemistry | ISM and star formation | 2024-05-05T16:50:25.000 |
| 4702 | 2018.1.00638.S | 57 | Further observations of R Aqr | This is a continuation of a successfull project, 2017.1.00363.S, devoted to study the line and continuum emission in the symbiotic stellar system (SS) R Aqr. R Aqr is a prototypical SS, a binary with an AGB star and a white dwarf that show a strong interaction. Our cycle 5 observations show for the first time the flow of material between both stars and the gravitational effects of the secondary on the wind from the AGB: the mass loss is strongly focused in the orbital plane and a double spiral appears. The data are strikingly in agreement with predictions from our preliminary hydrodynamical models. We also detected the birth of the bipolar jets (at scales of some AU!), which extend several arcmin at other wavelengths. However, the attained resolution, 30x40 mas, is hardly enough to detect the crucial phenomena, since the stars are separated by 30-40 mas. Particularly, the flow between both stars requires confirmation from maps with the highest resolution. In addition, a good analysis of the data, both in lines and continuum, requires observations at several wavelengths. We propose to observe also in bands 7 and 9, including data of the continuum and the CO J=2-1 and 6-5 lines. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2020-12-23T16:11:31.000 |
| 4703 | 2013.1.00726.S | 35 | Probing magnetic fields in the inner envelopes of Class 0 protostars via dust polarization | We propose ALMA Band 7 dust polarization observations of 3 Class 0 protostellar cores in Serpens in order to infer their magnetic field morphologies. These sources were previously mapped at CARMA with 2.6" angular resolution. The CARMA maps showed that in 2 of the 3 cores the magnetic field is poorly aligned with both the large scale field in the surrounding molecular cloud and with the bipolar outflows from the protostars. With 0.36" resolution, the ALMA observations will test the hypothesis that the magnetic fields in these sources are wrapped up toroidally by core rotation on scales of a few hundred AU. Such field wrapping could help to resolve the problem of the "magnetic braking catastrophe" that impedes the formation of Keplerian disks. Band 6 molecular line observations with comparable angular resolution of the same sources will be used to constrain outflow directions and core rotation axes. | Low-mass star formation | ISM and star formation | 2017-02-06T03:50:50.000 |
| 4704 | 2022.1.00520.V | 0 | NGC4261: the 2nd jet at < 50 gravitational radii (and the 3rd black hole shadow?) | We request EHT+ALMA 230GHz imaging of the twin jet bases of NGC4261. Among the eight AGN which the EHT can image at <100 gravitational radii, NGC4261 was identified as having the strongest (beyond SgrA* and M87) EHT flux in the March 2022 observing run. We thus have the unique opportunity to 'bridge the gap' between SgrA* and M87, and image a second jet base (after M87) at <50 gravitational radii, and perhaps the third black hole shadow (after M87 and SgrA*) if super-resolution imaging is possible. Our immediate aim is to constrain jet launching and collimation theory with the base of the twin jets in NGC4261: specifically the morphology of the jet base, its lateral profile, core-shift from the black hole, magnetic field and orientation. Quasi-simultanous VLBA and GMVA imaging will be proposed to enable these goals, but the EHT+ALMA observations are the crucial ingredient. The morphology and flux of the nuclear emission will also constrain emission from the accretion inflow and allow constraints on whether future 'super-resolution' imaging can image the black hole shadow in NGC4261. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 3000-01-01T00:00:00.000 |
| 4705 | 2022.1.01182.T | 137 | Constraining Jet Formation and Evolution with X-ray Binaries | Relativistic jets launched by accreting black holes can affect star formation, galaxy evolution and even the distribution of matter in the universe. Therefore, it is essential that we understand the process of accretion and the physics of these accretion-fed outflows. Black hole X-ray binaries (BHXBs) provide ideal laboratories for probing jet phenomena due to their rapid (day-week) evolution timescales. In particular, broad-band spectral measurements of jet emission in BHXBs during bright outburst periods allow us to constrain the physical conditions in the jet, which can then be coupled to the properties of the accretion flow, probing the mechanisms that govern how jets are launched and quenched. The mm/sub-mm regime bridges a crucial gap between radio and IR frequencies, as data in this regime are essential when performing detailed spectral modelling. We propose targeting the next outbursting BHXB with ALMA ToO observations, to accurately measure the evolving mm/sub-mm flux. Coupled with our exceptional multi-wavelength coverage, we will constrain the dynamic broad-band spectral energy distribution in BHXBs with unparalleled accuracy. | Black holes, Transients | Stars and stellar evolution | 2023-10-17T22:48:07.000 |
| 4706 | 2015.1.00578.S | 20 | Probing the role of magnetic fields in the formation of a massive protobinary | A large fraction of stars are found in binary and multiple systems. Direct observations of the earliest and deeply embedded phases of these objects, in particular the high-mass ones, are extremely difficult. High-mass star forming region IRAS 16547-4247 is best known for a precessing radio jet which is the brightest of its kind in our Galaxy. With the Submillimeter Array CO observations, we discovered a collimated, parsec sized outflow which is surprisingly precessing in a sense opposite to that of the radio jet. Thus we are very likely observing a twin jet originating from a massive protobinary. The SMA dust polarization observations reveal an ordered magnetic field threading the 0.1~pc dense core which harbors the binary. Here we propose for ALMA observations with a 0.3" resolution of the dust polarization to resolve the magnetic field orientation on the 0.01~pc scale. A joint analysis of the magnetic field and kinematics from 0.1 to 0.01~pc scales (the latter is already available from the SMA and existing ALMA molecular line observations) provides a direct test to our interpretation of the formation and dynamical evolution of the massive binary. | High-mass star formation | ISM and star formation | 2018-03-13T17:53:04.000 |
| 4707 | 2023.1.01150.S | 0 | A Survey of Infall in the Very Early Stages of High-Mass Star Formation | Recent ALMA surveys of massive 70 µm dark clumps yield hundreds of low-to-intermediate mass cores (and no high-mass prestellar cores), despite these clumps having the capability to form high-mass stars. Such findings lead to the conclusion that some of the detected cores must accumulate a significant amount of mass to become sufficiently massive to form high-mass stars, favoring clump-fed star formation scenarios. However, no characterization of infall rates has been systematically carried out to confirm if the high infall rates, of the order of 10E-3 - 10E-4 Msun/yr, are possible and if they are a common feature of cores at the earliest stages of high-mass star formation. In this proposal, we aim to determine what is the contribution of accretion on the line of sight and along filaments connected to cores. We have selected the ~40 most massive, sub-virialized cores among ~800 cores that are likely under collapse. Observing HCO+ J=3-2 and N2H+ J=1-0, we will derive infall rates (radial and/or along filaments) to evaluate whether these cores can accrete sufficient material to become massive and form high-mass stars in the future. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2025-07-01T10:10:05.000 |
| 4708 | 2017.1.00082.S | 314 | Molecular tori in Seyfert galaxies | Unified theories of AGN assume that a molecular torus, of a few to 10pc-size, is responsible for obscuring the BLR around the SMBH in Type-2 nuclei. ALMA has recently detected and isolated, for the first time, a ~10pc-diameter molecular torus of ~1e05Msun in the Seyfert 2 galaxy NGC1068 (García-Burillo+2016). Surprisingly, the NGC1068 torus is tilted and its kinematics is distorted by strong non-circular motions. A key question is whether these perturbed tori are to be found ubiquitously in Seyferts, and/or if their properties may change as a function of the AGN luminosity, the degree of obscuration and/or the Eddington ratio. We propose to map the CO(3-2) and HCO+(4-3) lines and their underlying continuum emission with a resolution of 0.1"(~7-13pc) in the circumnuclear disks of 10 nearby Seyferts from the ultra-hard X-ray selected AGN GATOS sample. With these observations we will detect and isolate molecular tori and have a sharp image of their connection to the hosts. This sample expands the range of AGN luminosities and Eddington ratios covered by other ongoing ALMA surveys of Seyferts like NUGA, led by members of our team (F.Combes, S.García-Burillo). | Active Galactic Nuclei (AGN)/Quasars (QSO), Galactic centres/nuclei | Active galaxies | 2020-11-22T10:46:57.000 |
| 4709 | 2013.1.00862.S | 3 | The discovery of molecular gas in the nearest cool core cluster of galaxies with ALMA | We propose an ALMA Band 6 observation aimed at detecting CO(2-1) line emission from a filamentary structure of cold gas located southeast of the centre of M87, the brightest cluster galaxy in the Virgo Cluster. There are clear signs of ongoing interaction between this filament and the radio lobes of the AGN in M87. This filament was previously observed at a range of wavelengths, including [CII] line emission with Herschel-PACS, which strongly suggests the presence of molecular gas. ALMA is not only in a unique position to offer the very first detection of molecular gas from the nearest cool core cluster, but also to provide unique information about the distribution and dynamics of this gas. The filament we propose to observe has already been detected with exquisite arcsecond-resolution in Halpha and FUV images from HST, and in soft X-ray emission from Chandra. In only 3h on source, ALMA will complete the coverage of all the gas phases present in this cool-core, allowing us to test models about the origin of the cold gas and its interaction with the AGN radio lobes with truly unprecedented detail. | Galaxy groups and clusters | Cosmology | 2016-08-25T02:54:15.000 |
| 4710 | 2017.1.01305.S | 17 | [OIII]88, [CII]158 and dust continuum survey in a z=8.4 hyper overdensity of galaxies | An extremely compact and dense overdensity of z~8 LBGs with delta~130 was found behind Abell 2744 cluster, hereafter A2744z8OD. A comparison of A2744z8OD with a model counterpart overdensity found in a semi-analytic model suggests that A2744z8OD is a progenitor of present-day clusters of galaxies and a number of galaxies associating with A2744z8OD are awaiting discovery. Recently, the spectroscopic redshift of one of the member LBGs of A2744z8OD was identified as z=8.38 with a tentative detection of the [OIII] 88 micron line. Here we propose deeper and wider observations in Band 7 for the [OIII] line and brand-new Band 5 observations for the [CII] 158 micron line as well as dust continuum from galaxies in A2744z8OD. The science goals of this program include (A) determining spectroscopic redshifts of galaxies of A2744z8OD with the [OIII] and/or [CII] lines, (B) investigating the ISM properties of the galaxies through the [OIII]/[CII] line ratio, (C) detecting dust continuum from the galaxies, and (D) performing a blind search of [OIII] and [CII] line emitters associated with the overdensity. | Lyman Break Galaxies (LBG), Galaxy Clusters | Galaxy evolution | 2019-11-21T17:37:12.000 |
| 4711 | 2013.1.01153.S | 12 | Revealing Major Mergers Among the Extreme Star Forming Hosts of the Fastest Growing Super-Massive Black Holes at z~4.8 | We propose a pilot study to probe the host systems of fast-growing Super-Massive Black Holes (SMBHs) at z~4.8, which would likely become the most massive BHs known (M_BH>=10^{10} M_sun) before z~4. Our Herschel observations show that these sources are hosted in two types of extreme star-forming (SF) galaxies: one with SFR>2000 M_sun/yr, indicative of major mergers as the common triggering mechanism for both SF and AGN activity, and another group with SFR~450 M_sun/yr, that may be related to secular evolution, or to AGN-driven feedback. The proposed ALMA observations will test this scenario, by probing the distribution of gas and SF, at scales of ~2 kpc, in the host systems of three objects in each group. The luminous [CII]157.7 um line, which may be detected in most of the sources, would probe the dynamics of the hosts and will provide a clear test for the occurrence of major mergers. The [CII] line would also allow us to estimate the dynamical masses of the hosts, and thus estimate the M_BH/M_dyn ratio at z~4.8. Thus, ALMA can probe the relevance of major mergers, possible feedback or secular growth for a well-defined sample of high-redshift, fast-growing BHs and host galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2016-08-27T08:12:19.000 |
| 4712 | 2015.1.00952.S | 10 | What Powers the Lyman alpha Blobs? | Narrow band imaging is a powerful tool to search for high redshift star-forming galaxies via Lyman alpha emission. With this method, a particular class of objects, known as "Lyman alpha blobs" (LABs), has been identified and characterized by their large physical extent of 30 to 200 kpc. The origin of Lyman alpha emission in LABs is still unclear and under debate. Our deep radio data from ATCA and far-infrared (FIR) archival data from Herschel in protocluster J2143-4423 show that radio and FIR emission is detected in two out of four LABs. These multi-wavelength band data are useful to study the properties of LABs. However, observations with higher angular resolution and sensitivity are definitely needed to reveal the spatial fine structure of the FIR emission and to identify the expected more compact individual galaxy-sized sources whose properties then can be studied in detail. The paucity of detections make the available information very biased and we also need to oberve a large sample. We therefore propose to observe two FIR-detected LABs in J2143-4423 and a large unbiased sample in SSA 22 to study the heating mechanism of LABs and test the star formation (SF)-based model. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2017-07-25T17:54:11.000 |
| 4713 | 2019.1.00165.S | 60 | Understanding the Physical Origin of [CII] Deficit in Early Star-Forming Galaxies | The ionising output of early star-forming galaxies is key to understanding their role in cosmic reionisation. We have undertaken a detailed survey of a large sample of z=3 Lyman alpha emitters (LAEs) whose intense [OIII] 5007A emission indicates they are useful analogues of galaxies in the reionisation era at z>6. A now completed deep HST F336W imaging campaign finds a surprisingly high fraction show prominent Lyman continuum leakage with escape fractions ranging from 13 to 60%. Our photoionisation models indicate such high escape fractions may arise from star-forming regions that are density- (rather than radiation-) bound, consistent also with the high [OIII] to [OII] line ratios. Such star-forming regions may also explain the puzzling ``[CII] 158um deficit'' seen in several high redshift galaxies given that line partly originates from photo-dissociation regions. We request time to study [CII] emission in a representative subset of our LAEs to examine the correlation between our individually-measured escape fractions and the strength of [CII] and hence to test the density-bound hypothesis. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2022-06-29T14:56:33.000 |
| 4714 | 2018.1.01140.S | 236 | [NII] and [CII] disentangle the neutral and ionised interstellar medium in submillimetre galaxies at z~4.5 | We have identified a complete sample of 12 submillimeter galaxies at z~4.5 with serendipitously-detected [CII] 158 micron emission in ALMA Cycle 0-4 Band 7 data, which we target for [NII] 205 micron and deeper [CII] observations. [CII] line emission is increasingly being used as a tracer of the interstellar medium in high-redshift (z>~3) galaxies. However, [CII] data alone are complicated to interpret because [CII] is emitted from both the neutral and ionised interstellar medium. Observations of the fainter [NII] line are required to disentangle the phases of the interstellar medium in high-redshift galaxies. We will obtain deep [NII] and [CII] data to disentangle the contribution of ionised and neutral [CII] emission and accurately constrain the far-UV field strength in the photodissociation regions in z~4.5 SMGs. We will measure and compare the sizes of the [CII], [NII], dust continuum, and stellar emission regions, as well as measuring the dynamical masses of these high-redshift SMGs and identify any spectroscopic companions in the datacubes. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2021-03-02T21:36:32.000 |
| 4715 | 2015.1.00959.S | 100 | A Systematic ALMA Survey of the Most Massive Starless Clumps within 5kpc | By combining observations and catalogs from recent Galactic plane mid-infrared, far-infrared, (sub)millimeter, radio, and maser surveys, we have identified over 2500 massive starless clump candidates that lack evidence of current star formation in the 15 < l < 55 range of the first quadrant. This population of clumps represents the future sites of intermediate and high-mass star formation in the Galaxy and are excellent targets to obtain observational constraints on the initial conditions for clump fragmentation and intermediate/high-mass star formation. We propose to observe a sample of 12 of the most massive starless clump candidates (M ~ 500 - 4000 Msun) within 5kpc with ALMA at 1.3mm to study the physical and kinematical properties of individual starless cores. This survey will systematically characterize the core mass function and fragmentation down to 0.5 solar masses and 0.03pc scales while simultaneously constraining the virial parameter and kinematic structure of these regions. Deuterated species within the bandpass shall identify cores that are very cold and dense and that may be on the cusp of star formation. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-09-07T18:33:33.000 |
| 4716 | 2017.1.00857.S | 124 | Volatile locking in protoplanetary disks: linking carbon abundances from 0.1 to ~100 AU | As protoplanetary disks evolve, their volatile species reservoirs change due to processes such as photodissociation, chemical reactions, freeze out, and grain growth. Recent observations in a handful of disks have found volatile carbon to be more depleted from the gas phase than can be accounted for solely by photodissociation and freeze out. Low CO gas masses in a survey of disks in Lupus suggest that depletion may be widespread. The missing volatile carbon is likely sequestered in grains as CO ice and converted to less volatile ices by grain surface reactions. Grains trapped outside of their sublimation radii would lock the volatile carbon into larger bodies. To observe carbon locking, we must compare volatile carbon abundances from inside of the dust sublimation radius with those of the outer disk. We have a set of disks in which we observe a series of C^0 lines in the near-infrared from within the dust sublimation radius. We propose to obtain observations of the C^0 line at 492.161 GHz with ALMA. Modeling both the inner and outer disk carbon abundances with a disk chemistry model will probe how much carbon-rich dust is locked into the large grains in the disk. | Disks around low-mass stars | Disks and planet formation | 2019-09-17T15:21:54.000 |
| 4717 | 2023.1.01425.S | 0 | Investigation of the molecular environment that caused fewer high-mass stars in the Small Magellanic Cloud | The physical processes that dictate the fragmentation of a giant molecular cloud (GMC) determine the stellar initial mass function (IMF). Numerical simulations show that a low-metallicity (Z) enviroment is expected to have inefficient cooling gas that forms fewer low-mass stars and flattens the IMF. The Small Magellanic Cloud (SMC) with low Z<~0.2 Zsun exhibits a dearth of very high-mass stars from a full GAIA census of the whole galaxy, invoking the explanation of a steep IMF. The new unbiased APEX CO(3-2) survey of the SMC, however, shows a flat cloud mass function similar to galaxies forming massive stars and clusters. Though the limited resolution (6 pc) and the unknown excitation conditions of CO(3-2) measurements prevent further investigation on differences among simulations and observed stars and gas. We request ACA observations on a large cluster of CO clouds in the center of the SMC Bar in Band 3+6 in multiple transitions with the aim to infer physical conditions precisely and to achieve a resolution down to clump scales (2 pc) where star formation actually happens. The results would have profound implications in star formation studies of the low Z early universe. | Magellanic Clouds | Local Universe | 2025-07-08T10:05:19.000 |
| 4718 | 2016.1.01214.S | 11 | ALMA observations of Hydra-A - Resolving a cold gas disk | We propose to map the cold gas disk that appears to be fueling the powerful radio galaxy Hydra-A by observing the CO(2-1) line at 250pc resolution. As a result of our viewing angle to this particular radio galaxy, Hydra-A has a very prominent edge-on disk that is detected in CO with IRAM 30m, [CII] and [OI] with Herschel and resolved in detail in warm molecular Hydrogen by VLT Sinfoni and ionised Hydrogen by VLT MUSE. Very deep Chandra observations of the intracluster medium set very reliable constraints on the amount of energy that has been inject mechanically into the central region of the cluster over the past 1Gyr due to the favourable viewing angle we have to Hydra-A with the jets in the plane of the sky. We request ALMA observations to exploit this fortuitous alignment for this powerful source to determine the gas dynamics within this relatively rare gas disk and to put it into the context of the other central cluster galaxies already observed with ALMA. | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy groups and clusters | Active galaxies | 2018-01-28T00:18:43.000 |
| 4719 | 2018.1.00187.S | 36 | Lithium isotope ratio 6Li/7Li in ISM at z=0.68 | Both 7Li and 6Li abundances observed in atmospheres of unevovled halo stars are known to be significantly inconsistent with the standard Big Bang Nucleosynthesis (BBN) prediction (lithium problems). However, whether the standard model should be modified to explain the observed values is contraversial dut to the difficulties of modeling stellar atmosphere and suggested Li destruction processes in stars. Here we propose to observe 7LiH and 6LiH molecular absorption lines in ISM as a new and independent probe of the Li abandunce. Our target is z=0.68 absorber in front of the BL Lac obsject B0218+357, in which two tentative but indepedent detections of the 7LiH(1-0) absorption line have been reported. We measure the isotope ratio 6Li/7Li in ISM at the cosmic time diffrent from our Galaxy, which definitly provide us with a new and strong constraint toward the standard model. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-02-01T22:59:12.000 |
| 4720 | 2023.1.00762.S | 0 | Hunting for Wolf-Rayet Feedback on Metal-Poor Star-Forming Gas | Stellar feedback from massive stars is vital in regulating star formation in galaxies. Wolf-Rayet (WR) stars, with their high temperatures, strong ionizing radiation, and massive stellar winds, have a significant impact on the nearby molecular medium, but there are few studies exploring these effects directly. We propose to map the HII region N76, which hosts one of the hottest and most luminous WR stars in the Small Magellanic Cloud, in 12CO (2-1) and 13CO (2-1) at 0.2 pc (0.7'') resolution to study the effect of WR feedback on the low metallicity molecular gas. Ancillary infrared observations and lower resolution CO data show evidence that the molecular clouds in this region are shocked and heated, but higher resolution CO data is needed to resolve these clouds and quantify the energy injected into the surrounding environment. These new observations will allow us to calculate the external pressure on the clouds, search for kinematic signatures of cloud destruction, and measure the effect of feedback as a function of distance from the WR star. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2025-09-24T01:28:36.000 |
| 4721 | 2013.1.00773.S | 1 | Spatially Resolving the Planetesimal Disk around HD 95086 - A Young Analog of HR 8799 | HD 95086 is a younger analog of HR 8799 based on the similarity in their planetary configuration -- the warm and cold debris produced from the leftover planetesimals that are dynamically sculpted and perturbed by the directly imaged giant planets. The resembling is further enhanced by the discovery of a disk halo in HD 95086 through re-analysis of Herschel resolved images. This exciting discovery suggests that the formation process of such a system might be common, and provides a unique opportunity to address the questions about such system's formation and evolution. Millimeter-wavelength observation of the debris disk with ALMA can provide a unique new window into the structure and dynamics of the HD 95086 system. By spatially resolving the cold debris disk at high signal-to-noise for the first time, we will better understand the nature of the extended halo of small dust grains observed at far-infrared, and place valuable dynamical constraints on the mass of HD 95086 b, assess the the presence of other unseen planets, and determine the prospects for long-term dynamical stability of the system. | Debris disks, Exo-planets | Disks and planet formation | 2016-11-19T00:00:00.000 |
| 4722 | 2021.2.00121.S | 22 | A complete high-resolution picture of cloud assembly and evolution, star formation, and feedback processes in NGC7793 | The physical mechanisms responsible for the full star formation process, from the assembly of atomic gas into molecular clouds, followed by (un-)obscured star formation, and feedback-created HII regions, remain ill-constrained. Such studies require a multi-wavelength, high-resolution approach. NGC7793 is ideal for this purpose thanks to its proximity (3.6 Mpc) and a wealth of ancillary data (HST, Spitzer, GALEX, VLA, MUSE, and planned observations with JWST), including ALMA 12m-array CO(2-1) observations. These ALMA data however only lack short-spacing observations, required to trace all of the molecular gas to robustly measure cloud properties and characterise the evolutionary timeline. We request 24 hr of ALMA ACA time to cover the full NGC7793 disk in CO(2-1) at 5.4" (94 pc) resolution. In combination with existing multi-wavelength observations, we will (1) measure the physical properties of the molecular gas in the entire disk of NGC7793; (2) construct the full evolutionary timeline of cloud evolution and star formation; (3) constrain the duration of embedded star formation, and the fraction of (un-)obscured star formation. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2023-05-24T10:48:07.000 |
| 4723 | 2018.1.01243.S | 184 | A detailed map of the variation of density, temperature and photo-dissociated gas across the Carina Nebula | The physical connection between star formation activity and the availability of dense gas to feed that stellar formation at a given time is of critical importance for our understanding of how stars form. A detailed picture of this relation in galaxies is needed if we aim to explain the complex process of star formation. We propose to use ALMA Band 3 to perform high spatial resolution observations of the densest and cold gas toward two distinct regions in our nearest region of extreme massive star formation, the Carina Nebula Complex. Our selected molecular line transitions which include N2H+, 13CO, C18O, C17O, CH3CN and CN, among others, will provide valuable information about the range of gas densities traced by each of this tracers, the temperature and level of photo-dissociation of the material in two regions with extremely different exposure to massive stellar feedback. This proposal is part of an ALMA observational campaign started in Cycle 4 to investigate the connection between the cloud internal structure, physical properties of the gas and the ability of the cloud to form stars. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2020-11-13T17:11:52.000 |
| 4724 | 2012.1.00671.S | 0 | Submm water maser emission in the Circinus galaxy | Water maser lines are still the only available means of probing the physical condition and accurate geometry of an accretion disk within less than 1 pc of the active galactic nucleus (AGN). Sub-millimeter water masers will allow us to improve further our unsterdanding of AGN physics and to effectively map so far unexplored regions. This is only now made possible given the sub-millimiter range, sensitivity and resolution that ALMA provides. We propose here a sensitive search for sub-millimeter water maser lines at 321, 325 and 658 GHz towards the Circinus galaxy, which is the nearest AGN hosting a powerful water maser pc-scale disk, previously studied at 22 GHz. The detection of these sub-millimeter lines will give us an entirely new insight into the kinematics and physical state of the accreting material in Circinus, probing regions in which longer wavelength maser emission is subject to obscuration. An analysis of the strength and distribution of these lines will allow us to: i) map the gas temperature and density at very high angular resolution, ii) improve our geometric disk models, iii) test unification schemes and iv) constrain radiative transfer models, by placing tighter constraints on the still unclear excitation of water. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2016-10-29T08:12:54.000 |
| 4725 | 2013.1.00815.S | 7 | Are low metallicity and dust mass common in high-redshift, UV-luminous starbursts? | ALMA has great potential for studying the interstellar medium in the most distant galaxies. The [CII] line is expected to be the strongest line observable at z>5 and will be used for accurate redshift determination, probing the dynamics of the ISM and the physical conditions in star-forming regions. However, the non-detection of the z=6.6 UV-luminous star-forming galaxy Himiko casts into doubt whether most high-redshift star-forming galaxies have high enough metallicity and dust mass to be detectable with ALMA. We propose a study of three UV-luminous z=6 star-forming galaxies to determine whether the far-IR properties of Himiko are typical of this class of objects or instead related to its unusual extended Lyman alpha halo. These observations are important for understanding the future role of ALMA in high-redshift studies. | Lyman Break Galaxies (LBG), Starburst galaxies | Galaxy evolution | 2016-05-25T15:29:15.000 |
| 4726 | 2023.1.01269.S | 0 | Unveiling the effect of AGN activity on CO excitation at cosmic noon | Feedback from AGN is expected to have a direct impact on the gas properties of their host galaxies. Several studies at z~2 show that AGN feature lower molecular gas masses (from low-J CO transitions) when compared to inactive galaxies. These results rely on arbitrary assumptions on CO excitation properties. Therefore, without direct constraints on the CO SLED, it is not possible to discriminate if AGN are gas poor or the low-J CO flux is due to a higher gas excitation. We propose a joint ALMA-VLA program to build a unique set of CO SLEDs from CO(1-0) to CO(10-9) for 8 galaxies at z~2. Our targets are selected to have similar redshift, M*, SFRs, and include both AGN and inactive galaxies. This will allow us to investigate the variety of ISM excitation conditions in these sources by taking into account star formation and AGN activity. This project capitalizes on an unprecedented multi-wavelength complementary coverage (X-ray to radio). We will determine the physical conditions of the ISM as a function of galaxy/AGN properties (SFRs, X-ray luminosity, outflow properties) and explore the main source of excitation in our targets' ISM (ionized outflows and presence/absence of an AGN). | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-11-18T14:31:00.000 |
| 4727 | 2012.1.01022.S | 2 | An Off-Nuclear Starburst in the Luminous IR Galaxy IIZw96 | The infrared luminous galaxy merger IIZw096 contains an extremely compact off-nuclear starburst that is the source of more than 80% of the total infrared luminosity. IIZw096 is a rare example of a galaxy caught in the early merger stage of driving its vast reservoirs of molecular gas inward toward what will become the merger remnant and is reminiscent of the more famous merging galaxy NGC4038/9 (the Antennae) but an order of magnitude more luminous at log(LIR/Lsun) = 11.94. We propose to map the off-nuclear starburst on spatial scales of 0.18"-2.5" over the entire starburst region. Given the small spatial extent and the need for extremely high sensitivity and spatial resolution, we request observations in the most extended configuration of Band 7 to trace the molecular gas via CO J=3-2, HCO+ J=4-3 and CH3OH J=4-3, and to measure the 850um dust continuum all on scales of 120pc- 2kpc. The resulting high spatial resolution maps will allow comparisons between the distribution of the bulk of the molecular gas (via CO J=3-2) and dust (at 850um), the location of higher density clumps (from HCO+ J=4-3 and CH3OH J=4-3), and structures seen in the near-infrared. The velocity will reveal possible infall or outflows of gas as well as pinpoint the dynamical center and how it relates to the density and temperature of the gas. Together the morphology and kinematics of the dense (cool) molecular gas that dominates the mass and fuels the star-formation will reveal the precise nature of the starburst and ultimate fate of the system. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2016-09-01T05:15:14.000 |
| 4728 | 2017.1.00236.S | 398 | Feeding and feedback in an unbiased and representative sample of AGN in the local Universe | We will map CO(2-1)in the central 3 Kpc of a representative and unbiased sample of 34 AGN in the Local Universe (D=10-50Mpc), from the 12µm all-sky sample. This is crucial to quantify the global AGN feeding and feedback and measure the time-averaged impact of these processes-the key unknown in theories of galaxy evolution. We will detect molecular outflows down to 10^5 Mo, derive outflow rates, gas reservoir masses and depletion timescales for the entire population of local AGN. We will identify the gravitational torques driving infall, and measure inflow rates. With the continuum maps we will measure dust masses, sizes and gas/dust ratios in the nuclear disks. We will observe 22 bright AGN in 27 hours which, when added to ALMA archival observations, will provide a sample of 34 AGN (14 Seyfert 1 and 20 Seyfert 2). We will compare these with archival ALMA maps of a similarly selected sample of LINERs. The legacy value comes from combining uniform CO maps for a relatively unbiased well-studied sample of bright AGN. We will identify the most suitable bright nearby AGN for ALMA high-resolution follow-up to dynamically constrain their black hole masses. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2019-02-15T00:54:24.000 |
| 4729 | 2016.1.01325.S | 68 | Chemical Characterization of a Candidate Warm Carbon-Chain Chemistry Source L483 | It is well known that low-mass protostellar sources show significant chemical diversity. So far, hot corinos characterized by rich saturated complex organic molecules (COMs) and warm-carbon-chain-chemistry (WCCC) sources characterized by rich unsaturated organic molecules are recognized as the distinct cases. Although intermediate chemical character sources are suggested by single dish observations, no definitive detection has been reported at a high resolution. With the ALMA Cycle 2 observation, we recently found the best candidate for the intermediate source, L483. Although it shows the WCCC at a few 100 AU scale, complex organic molecules such as HCOOCH3 and NH2CHO concentrated around the protostar at a 100 AU scale are likely detected. This is the first definitive detection of the WCCC source having a hot corino activity, if confirmed. In this program, we observe COMs in this source for confirmation, and quantitatively characterize its chemical and physical structure at a high angular resolution. The result constitutes an important base to understand the origin and the fate of the chemical diversity of low-mass protostellar sources. | Low-mass star formation, Astrochemistry | ISM and star formation | 2020-01-10T11:34:46.000 |
| 4730 | 2023.1.00022.S | 0 | ALMA-JWST Joint Efforts on Calibrating Gas-Phase Metallicities of Luminous Star-Forming Galaxies in the Reionization Era | The gas-phase metallicities of high-z galaxies are valuable probes of early galaxy assembly and chemical enrichment. However, traditional strong line methods rely on calibrations which have been shown to evolve with redshift due to the changing ionization properties of the ISM. While JWST has obtained direct measurements via the temperature-sensitive [OIII]4363 line in some low-mass galaxies at z>6, the line is too weak in massive/luminous galaxies with high metallicities due to low temperatures. We propose to obtain direct-method metallicities for 3 luminous galaxies at z>6 by observing the [OIII]52um line. Our targets are already detected in [OIII]88um and have approved JWST observations targeting the key rest-optical lines including [OIII]5007. The addition of [OIII]52um will provide electron temperatures, densities, and 0.1 dex precision metallicities for the massive galaxies, complementary to the [OIII]4363 detections in low-mass galaxies with JWST. ALMA [OIII]52um measurements are the only feasible route for enabling a robust metallicity and chemical evolution analysis of these targets, which will serve as the crucial calibrating anchor for more extensive JWST&ALMA studies. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2025-11-20T07:56:40.000 |
| 4731 | 2023.1.01065.S | 0 | A light in the dark: how early can substellar/planetary companions form in embedded protostellar disks? | The discovery of ubiquitous substructure, even in some very young sources, leads to the question: how early can planet formation begin? The BHB2007-01 (hereafter BHB07-01) system provides an interesting test case of an embedded protostar, with deep substructure and evidence for an embedded companion within the gap from centimeter to near-IR wavelengths, but with a large range of possible masses extending from protoplanetary to proto-brown-dwarf-sized. Moreover, the protostellar disk is still being fed from large scale filamentary streamers observed in 12CO extending beyond 1000 au. We propose to critically examine this source on both the micro-scale - quantifying its heating effects and thus its luminosity - and its kinematic perturbations on the disk, if any. We will also confirm the nature of the filaments on the macro-scale, by employing C-1 and ACA observations to recover the flux on larger scales to investigate how the filaments and the disk are interconnected. Together, these data will provide a comprehensive view of how companion/planet-formation proceeds in very young systems. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2025-04-29T21:29:15.000 |
| 4732 | 2016.1.00776.S | 22 | Interstellar Medium of a million solar low mass, low metallicity (6% solar) star-forming dwarf galaxy at z=1.847 | We propose for ALMA CII and dust continuum observations of a redshift 1.847 lensed starformating galaxy with an intrinsic stellar mass of million solar masses, a star-formation rate of 2-8 solar masses per year and six percent solar nebular metal abundance. While it appears as a LIRG due to magnification by a factor of 40, its intrinsic luminosity is that of a sub-LIRG at the level of 1e10 solar lumunosities. As an initial step in understanding the ISM, we propose to connect the rest-frame far-IR observations to the optical/near-infrared propertie determined extensively with Hubble and ground-based facilities. The immediate goals are: (a) Detect spatially resolved CII and dust emission (at 50pc spatial resolution); (b) Use CII/LFIR to confirm whether this galaxy is similar to low-redshift dwarf galaxies or star-forming galaxies during reionization; (c) use resolved CII velocity structure to constrain the dynamical mass;(d) use stellar mass from SED models and CII to estimate gas mass fraction; and (e) study spatial variations in dust emission and CII, as well as CII/LFIR, as a function of the UV slope, OIII equivalent width, and nebular line intensities. | Gravitational lenses, Galaxy structure & evolution | Cosmology | 2018-03-02T21:49:34.000 |
| 4733 | 2018.1.00460.S | 3 | Measurements of the magnetic field structure in the nearest protoplanetary disk | Magnetic fields are crucial for the evolution of planet-forming disks. However, observational constraints are still pending. TW Hya, the closest and brightest analog of the solar nebula, is a show-case example for studies of planet formation. TW Hya is also ideal for measurements of the magnetic field structure thanks to its almost perfect face-on orientation and very high degree of axial symmetry. Our aim is to obtain a resolved map of the magnetic field in TW Hya, and so uncover a key element in protoplanetary disk evolution, for the first time. Our previous (unpolarized) ALMA observation of CN(3-2) in TW Hya reveal that its (tau~1)-surface is located at the disk's mid-plane. This makes CN(3-2) the ideal tracer for a direct measurement of the magnetic field in TW Hya. Further, we will constrain the source of the continuum polarization by multi-wavelength polarimetry in conjunction with the linearly polarized CN(3-2) line. This project will verify the magnetic field in the nearest protoplanetary disk, probe for grain growth, and uncover the polarizing mechanism behind continuum polarization, for the first time. | Disks around low-mass stars | Disks and planet formation | 2020-09-13T19:25:54.000 |
| 4734 | 2022.1.00168.S | 9 | [CII]LIBRATE: The first systematic comparison of [CII] and CO(1-0) in high-z galaxies | Measuring the molecular gas content of z>4 galaxies is critical for our understanding of the stellar mass buildup in the early Universe. However, in this redshift range, traditional tracers such as low-J CO emission become increasingly unreliable. While recent observational and theoretical work suggests that the bright [CII] emission can be a powerful alternative tracer of molecular gas, its reliability has not been properly assessed, and the [CII]-to-Mgas conversion factor remains highly uncertain (to 1.5 dex). To settle these issues, we propose [CII]LIBRATE - the first systematic comparison of [CII] and CO(1-0) - the best tracer of molecular gas - in the same high-z galaxies. We will target [CII] 158-um emission in 13 z=3-5 galaxies with legacy CO(1-0) JVLA imaging. In total, we request request 9 hrs of ALMA Bands 7 and 8 observations at ~0.5" resolution. This programme will establish the relation between [CII] luminosity and CO(1-0)-derived gas masses for high-z galaxies and determine the [CII]-to-Mgas conversion factor to within 0.2 dex. At a small time expense, this project will present a breakthrough in galaxy evolution studies at high redshift. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2024-01-04T16:54:50.000 |
| 4735 | 2021.1.00988.S | 66 | Tracing the molecular gas in tidal tails of recently quenched galaxies | Recent observations of post-starburst galaxies have revealed that they retain significant gas reservoirs (log(M/M_sun)~10) in the 100 Myr after they shut down their primary epoch of star formation. One extraordinary example, SDSS J1448+1010, shows signs of an unprecedented quantity of extended H2 that coincides with optical tidal features, indicating that the removal of gas via mergers may play a crucial role the quenching of massive galaxies. Here, we propose to assess whether spatially-extended CO(2-1) emission is common amongst merging and recently quenched post-starburst galaxies at z~0.6. These data will facilitate two primary tests: (1) the presence of H2 would provide additional evidence that galaxies retain molecular gas in the ~100 Myr after quenching and (2) the distribution of H2 relative to optical tidal features will assess whether merger-driven tidal stripping is endemic to the quenching process. Although we assert that SDSS J1448+1010 is unlikely to be a AGN-driven molecular gas outflow, we will evaluate possible differences between AGN-hosts (2) and galaxies without AGN (5) to further test this thesis. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2023-02-04T11:25:35.000 |
| 4736 | 2017.1.00698.S | 103 | Measuring the Emission of Stellar Atmospheres at Submillimeter/Millimeter Wavelengths | Our understanding of stellar atmospheres and our ability to infer architectures of extrasolar planetary systems rely on understanding the emission of stars at millimeter wavelengths. We propose to use ALMA to determine the stellar emission of Sirius A in Bands 3 - 5, as well as $\gamma$ Lep and $\gamma$ Vir in Bands 6 - 7. The proposed observations will be used (1) to determine submillimeter/millimeter intrinsic stellar fluxes for the sampled A and F stars and (2) to evaluate potential variability in the stellar emission. These observations are fundamental to testing stellar atmosphere models, are essential for evaluating the occurrence rate of stellar excess (used to infer the presence of unresolved dust), and are required for determining the dust spectral indices at the proposed wavelength | Debris disks, Disks around high-mass stars | Disks and planet formation | 2019-10-09T19:13:38.000 |
| 4737 | 2018.1.01784.S | 142 | Detecting the Full Range of z~4 Galaxies Associated with Damped Ly-alpha Systems | As a continuation of our extremely successful cycle 3, 4 and 5 programs to detect the z~4 galaxies associated with high metallicity damped Lyman-alpha absorbers (DLAs) in [CII] emission, we propose to observe ALL known DLAs between z~4.1 and z~4.5 with an accurate metallcity determination. This will constitute the first such sample at any redshift whereby we will cover a full sample of metallicity unbiased DLAs in order to search for the associated galaxy. This will allow us to: 1) determine the star formation rate (SFR), dust content, and size of the full range of DLAs at a given redshift 'slice'. 2) establish the extent of the HI absorption around z~4 star-forming galaxies. The current sample of galaxies associated with high-metallicity DLAs suggest that they are massive dusty, star-forming galaxies with large extended halos of HI gas. The proposed observations will determine if these statements are valid for the general DLA population as well. | Damped Lyman Alpha (DLA) systems | Cosmology | 2020-07-05T00:41:01.000 |
| 4738 | 2018.1.00164.S | 234 | A survey for the molecular gas content in star-forming galaxies at z~1.5: exploiting the VLT/KMOS and ALMA synergy | We propose a dual band ALMA survey in CO(2-1)/band-3 and CO(5-4)/band-6 towards 18 star forming galaxies at z~1.5 selected from the KMOS Galaxy Evolution Survey (KGES). Targets are carefully selected from a parent sample of ~500 galaxies presenting spatially resolved and good quality H-alpha dynamics. This survey will give a major step forward on the number of Halpha-selected galaxies with near-IR IFU data and CO detections at high-z. Our science goals are to: (1) get star-formation efficiencies in terms of the kinematic state of galaxies, (2) measure the gas to dust ratio to confirm the validity of the submm continuum as a tracer of the molecular gas content in "normal" high-z galaxies, (3) probe the cold vs warm molecular gas content to constrain the heating mechanism in these galaxies, (4) put further constraints on the MH2-L'co conversion factor by using metallicity ([NII]/Halpha) and dynamical arguments, (5) confront the amount of molecular gas content to semi-analytical cosmological prescriptions at z~1.5, and (6) in case of bright line detections, explore the ionised vs. molecular gas kinematics to infer the degree of stability in galaxy disks. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2020-07-23T09:57:54.000 |
| 4739 | 2013.1.00276.S | 7 | Physical Properties of Galaxies that Ionize the Universe | Measuring the properties of low-luminosity galaxies near redshift 6 is central to understanding the reionization of the universe. Although hundreds of bright galaxies have now been identified at this era, their number density is too low to even maintain the ionization of the intergalactic gas, and lower luminosity galaxies detectable only via their line emission provide the closest relation between any post-reionization galaxy population and the objects that actually reionized the universe. Prior to ALMA, however, our knowledge of these important galaxies was limited to number counts and luminosity functions of hydrogen Lyman-alpha emission. The luminosity and line profile of this resonance line depend sensitively on the gas kinematics and dust content of the host galaxy, so Lyman-alpha observations alone provide little physical information about the galaxy properties. To establish the typical star formation rate, dynamical mass, and systemic velocity for the lowest luminosity galaxies yet detected at this important era, we request ALMA observations of their [CII] 158um fine structure emission. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2016-03-09T18:15:02.000 |
| 4740 | 2017.1.00740.S | 79 | The role of OH outflows in the high redshift Universe | Why were ultraluminous infrared galaxies (ULIRGs) at z>1 such a major contributor to the star formation density at that epoch, yet they contribute less than a percent today? A likely driver may be changes in Active Galactic Nuclei (AGN) feedback. Herschel observations of hydroxyl (OH) have proven extremely efficient in characterising AGN-driven outflows in the local Universe, and showing that they are relatively common. These outflows provide the only direct evidence that fuel for star formation is being removed. What are the properties of these outflows in the early universe? Are they powered by the same mechanism? We propose to complete our novel study of AGN-driven outflows in 3 ULIRGs at redshifts 2.6-4.2, with the best available outflow diagnostic, OH, and the best available sample of gravitationally lensed sub-mm galaxies, using the flux amplification to maximise ALMAs sensitivity to this key diagnostic. Our program will be the first detailed study of OH properties in ULIRGs in the high-redshift Universe. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2020-09-13T10:17:36.000 |
| 4741 | 2012.1.00955.S | 0 | Mass Loss from Massive Stars II | Massive stars have a crucial influence on the dynamics and energetics of the interstellar medium in galaxies due to their enormous luminosities and massive winds. This energy and processed material enrichment in turn influence further star formations in those galaxies. Therefore, a deeper knowledge about massive stars and their evolution is a prerequisite for improving our understanding of the Universe as a whole. The fast and dense stellar wind from massive OB type stars are driven by radiative line acceleration. It is thought that our understanding of massive star winds is well established. However, multiple evidence points to an over-estimation (by up to a factor of ten) of the currently accepted mass-loss rates from these stars as shown by inconsistencies in results derived using the linear and density-squared dependent diagnostics. The cause of the inconsistencies is attributed to wind clumping which strongly affects the density-squared dependent processes (recombination lines or free-free continua), but not so on linear-density-dependent processes(resonance-scattering lines or electron scattering profile wings). Models predicted that the clumping is radially stratified. Current observations study the base wind zones (H-alpha method), early intermediate zones (IR/FIR continua) and outermost zones (radio continua). However, a large region of the intermediate zone is currently unconstrained. The potential downward revision of mass-loss rates of massive stars will have a dramatic effect on the stars' evolution, on the corresponding feedback on their environments and hence on hte evolution of the host galaxy. Therefore we urgently need to establish the true mass-loss rates of OB stars, by constraining the clumping structure. If the radial stratification of clumping is known from consistent analyses by means of different diagnostic methods, realistic mass-loss rates can be derived. ALMA will provide the necessary sub-millimeter and millimeter observations to constrain the density/clumping structure in the intermediate wind zone, in which the wind is extremely sensitive to clumping. This knowledge is crucial to understand the inhomogeneities throughout the entire wind. In this proposal, we aim to obtain previously unknown mm/sub-mm fluxes from a carefully selected sample of OB-type stars for which we have information in other frequency ranges. The requested observations in the two or three ALMA bands will allow to accurately constrain the spectral indices of the SED which is controlled by the wind density and clumping structure. ALMA will provide the information which is mostly unknown thus far. The requested minimum SNR of 10 will allow us to detect the variation in the predicted flux levels by at least a factor of two in the ALMA bands, which in turn will show us the variation of clumping by factors of five to 10. With the crucial information provided by ALMA, we will be able to combine analysis of all diagnostics from the Far-UV to radio domain with consistency, in our elaborate Non-LTE wind models. This will lead us to the ultimate goal of derivation of clumping properties throughout the entire wind and help to constrain the physical origin of wind clumping. In summary, the proposed ALMA observation is essential for our understanding of wind flows and the magnitudes of mass-loss rates, and will provide an independent measurement of the amount of clumping in the wind. | Hypergiants, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-02-18T13:52:39.000 |
| 4742 | 2019.1.01251.S | 229 | SUPERCOLD-CGM: a high-z survey of molecular gas across the circum-galactic medium of Enormous Lya Nebulae | Massive galaxies at high-z are known to co-evolve with their circum-galactic medium, generally detected in Ly-alpha. However, a direct link between this CGM and the stellar growth of massive galaxies remained missing: we had yet to identify the reservoir of halo gas that can fuel widespread star-formation, namely cold molecular gas (~10-100 K). Following the discovery of a cold CGM in the Spiderweb and two other Lya nebulae, we propose to use ALMA + ACA to perform the first systematic survey of the molecular medium in a sample of 10 QSO-powered Enormous Lya Nebulae (ELANe) at z~2 for which 3D Lya imaging from the Keck Cosmic Web Imager is available. We will simultaneously target the low- and high-density gas tracers CI 3P0-3P1 and CO(4-3) to obtain the mass, extent, composition and physical properties of the multi-phase CGM. In addition, a commensal continuum study will be performed for free in search for the Sunyaev-Zeldovich Effect from quasar winds that deposit material into the CGM. Studying the multi-phase CGM with sensitive surface-brightness ALMA+ACA observations opens an exciting new window for investigating the early formation of the most massive galaxies in the Universe. | Lyman Alpha Emitters/Blobs (LAE/LAB), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2021-03-18T13:00:46.000 |
| 4743 | 2018.1.01091.S | 140 | Mapping M17: the best galactic laboratory for measuring the role of photoionizing feedback | Feedback is a central problem in astrophysics; it affects all stages and all scales of star formation. Recent numerical work has reexamined the role of ionizing feedback, showing that photoevaporation injects momentum into the cold molecular gas. In this way, ionizing feedback may (1) explain compressed layers and high pressures in PDRs; (2) carve dust pillars; and (3) resupply turbulence. High angular resolution observations of the cold gas kinematics are essential to test these predictions. Messier 17 (M17) has the highest degree of ionization of galactic star-forming regions and is unambiguously dominated by pre-supernova feedback, making it the ideal laboratory. We request an ACA mosaic of M17 to measure the cold gas kinematics as a function of position and therefore incident ionizing flux in order to measure the distribution of turbulence in the cold molecular gas. These data also allow us to (a) produce a high resolution map of the PDR, (b) detect dust pillars and protostars and measure their masses, and (c) estimate cloud destruction time. This cloud-scale survey allows us to conduct the first comprehensive study of the role of ionizing feedback in star formation. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 2020-07-02T00:24:15.000 |
| 4744 | 2017.1.00345.S | 22 | Central-Inversion Ly alpha Emission in a DLA | A number of lines of evidence have been accumulated in these decades for the presence of extended Ly alpha emission (or Lyman alpha blob, LAB) in damped Lyman alpha absorption system (DLAs) hosting galaxies at high redshift. This suggests that such DLA hosting galaxies are young galaxies in a phase of the superwind activity shortly after the intense galaxy-scale star formation. Therefore, it is important to explore possible physical connection between DLAs and LABs at high redshifts. Here, we propose to investigate such a DLA-LAB system found in the quasar Q2233+131; the DLA redshift is 3.1476. This DLA has an intense central inversion Ly alpha emission line. Since this property can be regarded as probable evidence for the superwind activity (Bond et al. 2001), this DLA-LAB system is suitable for our purpose. Our science goal is to detect [CII]157.74 emission associated with the LAB. Its morphological and dynamical properties are highly useful to explore the DLA-LAB connection at high redshift. The estimated observing time is only 1.12 hours. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2019-06-23T08:34:09.000 |
| 4745 | 2017.1.00227.S | 60 | Casting Light on Chameleon's Dark CO | In Cycle 4 proposal 2016.1.00714.S we searched for HCO+ absorption against 13 QSO-phase calibrators seen toward the Chameleon cloud complex, where the H I - H2 transition has been extensively studied in H I, CO, dust optical depth, extinction, and gamma-ray emission. The results were delivered in 2017 March. Although CO emission is seen in one or two directions, HCO+ absorption was present in all directions but one where the QSO flux was very low. Here we propose to observe 2.6mm 12CO absorption along six of the Chameleon sightlines (two clusters of three sources), to determine whether the CO is dark due to low CO column density or low number density and weak rotational excitation. The 5sigma upper limits on N(CO) derived from this work will be 10 times below those that would be inferred from the upper limits on CO emission alone. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-01-12T16:59:37.000 |
| 4746 | 2015.1.00223.S | 7 | Revealing Fragmentation of the Nearest Precluster Clump in Serpens South | The majority of stars form in clusters. Therefore, understanding the formation process of clusters is a key step toward a full understanding of how stars form. However, the initial conditions of cluster formation remain to be elucidated observationally because once active star formation is initiated, the stellar feedback such as protostellar outflows and radiation rapidly shapes their surroundings, making it difficult to track back the physical conditions of the clumps prior to active cluster formation, i.e., pre-protocluster clumps. On the other hand, recent 3D numerical simulations suggest that the physical conditions of pre-protocluster clumps determine some properties of forming clusters. Therefore, it is of great importance to reveal the physical conditions of the pre-protocluster clumps observationally. Recently, we discovered a NEAREST pre-protocluster clump that is located in the Serpens South infrared dark cloud (IRDC) at a distance of ~400 pc. Here, we propose a mosaic observation toward the nearest pre-protocluster clump with the finest spatial resolution of 1000 AU (~2.5") and reveal its internal structure and physical conditions. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2017-12-01T08:58:42.000 |
| 4747 | 2019.1.00783.S | 52 | Elucidating Titan's High-Altitude Nitrogen Chemistry | We propose to obtain accurate measurements of the 14N/15N isotopic ratios in three of Titan's most abundant nitriles: HNC, CH3CN and HC3N. Evidence for strong 15N fractionation on Titan has previously been found in HCN and HC3N, and is theorized to be due to isotope-selective photodissociation of N2 in the upper atmosphere. High S/N observations of the 15N fraction in multiple new species will enable rigorous, altitude-dependent tests for the latest photochemical models, particularly regarding the rates of N2 and 14N15N photolysis, and the importance of high-energy dissociative electron impacts. We also seek to detect for the first time the isocyanides CH3NC, HNCCC and HCCNC, that will elucidate ion-electron recombination rates and branching ratios in the upper atmosphere. By comparison with our team's state-of-the-art photochemical model (Vuitton et al. 2019), the resulting improved understanding of gas-phase nitrogen chemistry will provide new insights in the synthesis of nitrogen-bearing organics in primitive planetary atmospheres (including species of possible prebiotic importance), and will help constrain the origin of Titan's surprisingly large nitrogen reservoir. | Solar system - Planetary atmospheres | Solar system | 2021-04-02T21:18:07.000 |
| 4748 | 2022.1.01437.S | 0 | Jet launching Scenario at the early phase of protostars | Protostellar outflows and jets play a vital role in star formation as they carry away excess angular momentum from the inner disk surface, allowing the material to be transferred toward the central protostar. However, the jet launching and collimation process remain less explored due to lack of high-resolution observations of a statistically significant sample of protostellar jets. Based on previous ALMA observations, we have selected three sources having nearly edge-on orientation, well-defined SiO jet, knots close to the source to study (i) the jet launching zone, (ii) shock morphology and (iii) origin of gas phase SiO in the jet. We proposed to observe SiO(8-7) line in Band 7 at 0.02 arcsec and 0.2 km/s velocity resolution with a sensitivity of 1.6 mJy/beam (at 1 km/s). | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2025-01-04T18:42:40.000 |
| 4749 | 2023.1.01636.S | 0 | High-Resolution Mapping of the Molecular Gas in GW-recoil Candidate 3C 186 | The radio quasar 3C 186 has been recently identified as an excellent candidate for a 'kicked' super-massive black hole, a scenario theoretically predicted to occur under certain conditions when two super-massive black holes coalesce after the merger of their host galaxies. The radio-loud QSO in 3C 186 is separated 1.3" from the host galaxy isophotal center, and the broad emission lines appear blueshifted by 2100 km/s relative to the narrow lines. The currently favored explanation for these observations is that the broad line system tracks the kicked black hole (QSO), while the narrow-line system was left behind in the host galaxy. We propose to test this interpretation by mapping the system in CO(4-3) and CO(6-5) at high (0.1-0.16'') resolution, with the goal of tracing the exact location and redshift of the bulk of the cold gas reservoir, as well as determining the excitation state and extent of gas around the offset QSO. These observations are critical to understanding the history and dynamics of these rare extreme GW-recoil events, which result from anisotropic GW radiation during the BH-BH merger | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2024-11-10T02:26:45.000 |
| 4750 | 2021.2.00092.S | 60 | Revealing the molecular gas content of low-metallicity low mass strongly lensed galaxies | In the past decades, studies of massive high-z galaxies have revealed a strong relation between molecular gas and the rates and timescales of star formation. When exploring the lower mass range with, the help of gravitational lensing, galaxies have appeared to have less gas and/or to use their gas more rapidly than expected . This apparent gas deficit (relative to massive galaxies) can either be due to the systematic uncertainties of tracer-to-gas calibrations or to a fundamentally different mode of star formation taking place in these lower mass galaxies, but testing this can only be addressed with larger samples. Here we propose CO and dust continuum observations with ACA of six low-mass strongly-lensed star-forming galaxies at z~2-3. These observations will significantly expand the current sample of gas measurements in such objects, with the goal of improving statistics to confirm (or discard) the observed deficit. Additionally, by using two independent tracers we address some of uncertainties of tracer-to-gas calibrations. Finally, ACA and its large FOV and beam sizes is the best suited instrument to perform this survey. | Lyman Break Galaxies (LBG), Gravitational lenses | Galaxy evolution | 2024-06-06T00:00:00.000 |
| 4751 | 2013.1.00063.S | 25 | Resolving SN1987A: a detailed look at a unique laboratory of shock, dust, molecular, and nuclear physics | Supernovae drive the evolution of the ISM: they disperse heavy elements, inject mechanical energy, accelerate energetic particles, and create molecules and dust. SN1987A was the closest SN explosion to Earth observed since 1604, a unique target to study supernova and SNR physics. We will build on our Cycle 0 observations of strong CO and SiO emission, and exploit the high angular resolution of Cycle 2 to create the first 3-d resolved maps of these species in the ejecta of SN1987A, and the temperature and density of the ejecta. We will resolve the predicted clumpy structure, constraining instabilities that occurred during and shortly after the explosion. We will simultaneously image the high-frequency continuum. Our Cycle 0 observations found a very large mass of dust formed in the ejecta. The relative distribution of dust, CO and SiO emission will constrain dust composition and formation physics. A high-frequency spectral index map will help resolve the mystery of whether particles are accelerated at the forward or reverse shock, how that nonlinear particle acceleration changes as the shocks interact with the dense circumstellar ring, and the nature of the compact remnant. | Supernovae (SN) ejecta | Stars and stellar evolution | 2016-11-14T05:16:47.000 |
| 4752 | 2018.1.01517.T | 14 | Occultation of the radio galaxy J1513-4221 by the asteroid (61) Danae | Occultations of radio sources by asteroids provide an effective method of determining asteroid sizes and positions at the moment of the observation. The method is based on the modelling of diffraction fringes using the Fresnel-Kirchhoff theory. We propose to use ALMA to determine the size of asteroid (61) Danae, and to confirm, or disprove, the suggested existence of a moon around this asteroid. The orbit of the eventual moon around the primary body can be used to constrain the mass and the density of the asteroid. So far the statistics about these parameters are poor for these kind of asteroids. Here we wish to utilize the fortuitous occultation of the radio source J1513-422 by Danae that will be observable at ALMA on July 18, 2019. The proposed short measurement would be the first of its kind with a connected array, and it would constitute a very useful test for this powerful method. | Solar system - Asteroids | Solar system | 2020-11-01T23:55:13.000 |
| 4753 | 2019.2.00078.S | 9 | Ortho-H2D+ in the cores close to the onset of star formation | We propose to observe the ortho-H2D+ 1(1,0)--1(1,1) line at 372.42 GHz from two starless cores and one protostellar core in the Orion molecular complex. Two starless cores, G208.68-19.20-N2 and G209.19-19.65-S1, are considered to be evolved prestellar cores on the verge of star formation, because of their high [D]/[H] ratio of ~0.2 and high H2 volume density of ~10^7 cm-3. The protostellar core, G204.4-11.3-NE, harbors a source with very-low luminosity (0.027 L_sun) and low bolometric temperature (57 K).The deuterated molecules such as N2D+ and DNC are also abundant in this core, suggesting that this core is just after the onset of star formation. The ortho-H2D+ observations with the ACA allow us to study the spatial distribution of the ortho-H2D+ line at a resolution of 1500 au. We are able to study the variation of the orho-H2D+ abundance as a function of evolutionary stage. The orho-H2D+ emission line also allows us to study the kinematics of dense and cold region in which most of the molecules are depleted onto dust grains. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Astrochemistry | ISM and star formation | 2022-10-04T11:13:38.000 |
| 4754 | 2021.1.00871.S | 79 | The curious case of the ~40 Myr accreting M dwarfs: Late-stage protoplanetary disks or gas-rich debris disks? | Planet formation is believed to occur within the first 10 million years of a stars life, when the star is surrounded by a significant mass of gas and dust. This makes the recent discovery of a class of actively accreting ~40 Myr old M dwarfs curious. The optical emission lines and strong infrared excess are hallmarks of gas-rich planet-forming disks, but the ages are more consistent with that of debris disks. Prior observations of these systems were only sensitive to warm gas and dust, and could not constrain the presence of a massive reservoir of cold gas and dust. With ALMA we can sensitively measure the mass of the cold reservoir, down to 0.01-0.03 Earth masses, determining if these systems are late-stage protoplaneary disks, or gas rich debris disks. If they are gas-rich debris disks, we can distinguish between models for the origin of the warm gas and dust, as either fed by a cold reservoir or generated by the collision of massive bodies close to the star, based on the detection or non-detection of a cold reservoir. | Debris disks, Disks around low-mass stars | Disks and planet formation | 2023-04-28T17:14:26.000 |
| 4755 | 2013.1.01331.S | 0 | Direct Observation of Gas-Phase Methane: A Search for CH$_3$D in the WCCC Source, L1527 | Methane (CH4) is the most fundamental organic molecule, and is an abundant constituent in interstellar clouds and planetary atmospheres. In addition to this general importance, we recently found its important role in some low-mass star forming regions, called warm-carbon-chain-chemistry (WCCC) sources, where CH4 evaporated from grain mantle near the protostar triggers efficient production of various carbon-chain molecules. In this proposal, we aim at the first definitive detection of deuterated methane (CH3D) by observing its the J=1-0 and 2-1 lines in Band 6 and 8, respectively, in the WCCC source L1527. L1527 is an ideal source for this purpose because of a high expected abundance of CH4 and a warm and dense condition for rotational excitation. We have recently reported the tentative detection of CH3D in L1527 by a long integration observation with the single dish telescope (HHT), and hence, we would like to confirm this detection definitively with ALMA by observing the two rotational lines. This observation will open a new window to the CH4 science in star and planet forming regions. It will also be a definitive proof of the WCCC mechanism in L1527. | Low-mass star formation, Astrochemistry | ISM and star formation | 2016-03-23T17:06:17.000 |
| 4756 | 2017.1.00101.S | 36 | Magnetic Fields in High-Mass Star Formation | Now that: (1) ALMA has consolidated its polarization capabilities and (2) 800 hr of the 12m array (20% of 4,000 hrs) are allocated to non-standard observations, It is time for the next breakthrough from ALMA: to reveal the importance of magnetic fields in high-mass star formation. Polarization observations are finally feasible for large samples. For the first time, we aim to carry out a complete picture of the energy balance of high-mass star-forming regions at the scales directly related to the star-forming process (500-1,000 AU). By observing 26 high-mass star-forming regions, containing >60 cores, we will determine: i) if magnetic fields, turbulence, and/or gravity is the dominant source of energy. ii) and, with the help of numerical simulations, what control the different fragmentation scenarios observed in our sample. We have assembled a strong team for such a large program, including experts in ALMA data, polarization observations, and numerical simulations. | High-mass star formation | ISM and star formation | 2023-04-12T00:00:00.000 |
| 4757 | 2022.1.01392.S | 16 | SDC13, a hub-filament system originated from the collision of large-scale converging flow? | Theoretical simulations find that filamentary molecular clouds are formed at the converging locations of large-scale turbulent flows. These forming filaments could be further bounded by gravity, shaped and reinforced by the B-field, and eventually evolve to hub-filament systems (HFSs). SDC13 is a remarkable HFS, where both density structures, velocity profiles, and multi-scale B-fields all show evidence of large-scale flow collision. We propose follow-up SiO (2-1) observations with both ACA and Total Power toward SDC13, as the last piece of evidence to conclude that this system is indeed originated from a cloud-cloud collision event. In addition, moderate/high-density tracers can also be observed simutanesly with the proposed observation, which will be used to probe the bridge structures connecting the giant molecular clouds associated with SDC13. The results allow us to investigate how a HFS and the associated B-field are formed/modified by a cloud-cloud collision event. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2024-04-27T16:39:32.000 |
| 4758 | 2023.1.00609.S | 0 | A new, fast, ultradeep constraint on the gas content of the first generations of massive quiescent galaxies. | The question of whether quenching requires complete gas depletion does not have a clear answer yet. The recent discoveries of quiescent galaxies (QGs) at z>3 make this question even more compelling due to widespread cosmic gas accretion at early times. To find the answer, we propose to take advantage of a new method to measure the total gas fraction of high-z quiescent galaxies by using the brightest molecular gas mass tracer, i.e. the [CII] 158 microns emission line. This line has long been overlooked since it is predominantly used for star-forming galaxies. However, it becomes particularly useful for QGs at high-z since these are often selected with a cut in sSFRs relative to main sequence galaxies, thus likely retaining residual photodissociation regions. By exploting ALMA bands 7-8 we will observe gas fractions down to 1-2% (without strictly requiring strong lensing) in 6 spectroscopically confirmed QGs at 2.92.9. | Galaxy structure & evolution | Galaxy evolution | 2025-10-09T18:25:49.000 |
| 4759 | 2017.1.01220.S | 19 | Imaging Titan's Troposphere | We propose to use ALMA's uniquely powerful combination of resolution and sensitivity to map the thermal emission emanating from Titan's troposphere, in Bands 3, 4 and 6 at 100 mas resolution. These observations exploit a new way to measure the temperature field of the troposphere, and ALMA provides the only means to do so at high spatial resolution. In conjunction, we will submit a companion proposal for JVLA observations in A-configuration in Ka and Q bands at comparable resolution and sensitivity. The longer wavelengths are more sensitive to surface emission. By combining data from both programs, we will be able to remove the atmospheric contribution to the long wavelength images, resulting in high precision corrected surface brightness temperature maps with climatic and/or geologic implications. The combined ALMA/JVLA data will result in an unprecedented view of Titan's surface and lower atmosphere. | Solar system - Planetary atmospheres, Solar system - Planetary surfaces | Solar system | 2020-01-17T02:26:54.000 |
| 4760 | 2022.A.00025.T | 12 | The first millimeter observations of an "orphan" afterglow | AT2023lcr is the best "orphan afterglow" candidate to date, and could be the first member of a long-hypothesized but as-yet unobserved phenomenon: either an off-axis GRB, or a low-Lorentz factor dirty fireball. Three days after the initial optical discovery, a very strong detection was found at 10 GHz with the VLA. This is the first time a candidate orphan afterglow has such stringent constraints on associated prompt gamma-ray emission and such a bright radio detection so early in its evolution. Millimeter observations offer a unique diagnostic of relativistic blastwaves, especially via detection of the reverse shock. Given the bright radio detection, this event also has the possibility to become the first "orphan" afterglow studied at millimeter wavelengths. To complement the ongoing campaign to observe AT2023lcr across the electromagnetic spectrum, here we request ALMA observations in Band 3. The proposed ALMA observations, combined with approved centimeter observations and ongoing X-ray monitoring, will capture the forward shock (the afterglow) and the reverse shock, thereby enabling us to determine whether AT2023lcr truly represents a new class of explosions. | Transients | Stars and stellar evolution | 2024-01-20T22:24:34.000 |
| 4761 | 2018.1.00350.S | 9 | A snapshot of planet assembly in a solar nebula analogue | We request ALMA Band 7 observations to map the planet forming region of the disk around the young solar analogue star LkCa15 at a spatial resolution of 5 AU. Near-infrared and millimeter-wave observations of this source have revealed a complex disk morphology which likely resulted from the interation with young giant planets. This hypotesys is supported by the detection of Halpha emission from a putative massive planet orbiting at about 15 AU from the central star. Our project has two goals: (1) To detect the circumplanetry disk surrounding the candidate young accreting planet. (2) To investigate the interaction between the candidate planet and the circumstellar material. The proposed observations aim at obtaining the first robust detection of a forming planet in the microwave regime. This proposal is the resubmission of projects 2016.1.00531.S and 2017.1.00859.S that were awarded time in Cycle 4 and 5, respectively, but were not executed. | Disks around low-mass stars, Exo-planets | Disks and planet formation | 2020-12-13T21:40:41.000 |
| 4762 | 2011.0.00747.S | 0 | Mapping the [NII] 122 micron line in high-z galaxies. | We propose to greatly improve our study of the high-z galaxies SMMJ02399-0136 and H1413-117 (the Cloverleaf QSO) at z=2.81 and z=2.56 respectively, by adding high spatial resolution observations of the redshifted [NII] 122 µm line that only ALMA can provide. We have previously detected this line in these two sources using our instrument ZEUS on the CSO. Both sources reside at the epoch of peak star formation in the Universe and have been extensively studied at other wavelengths. Taking advantage of the resolving power and sensitivity of ALMA ES, we will identify the sources of the [NII] (star formation or AGN), characterize the starburst within each source, and probe the star formation rate/molecular mass relationship. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2014-02-08T17:22:00.000 |
| 4763 | 2024.1.01054.S | 0 | An exploration of the CO excitation in a spatially-resolved molecular gas outflow of a HyLIRG at z=0.5 | Massive molecular outflows is ubiquitous in ultra- and hyper-luminous IR galaxies (ULIRG and HyLIRG), which provides an important feedback mechanism to regulate the growth of galaxies. However, study on the connection between those molecular outflow and gas excitation is still in its infancy. A HyLIRG at z=0.5 is recently found to exhibit an enhanced CO(3-2)/CO(2-1) ratio in a spatially-resolved molecular outflow, which provides an excellent lab for a more detailed study of gas excitation in outflows. We propose ALMA observations of multi-J CO and [CI](1-0) for the HyLIRG, to investigate the high gas excitation as well as its association with shock heating mechanism in the outflow. The proposed study could be the first-ever spatially-resolved CO ladder analyses in molecular outflow, and shed light on the mechanism of outflow to affect the gas conditions, e.g., density and temperature, in the host galaxy. | Outflows, jets, feedback, Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG) | Active galaxies | 2025-10-25T02:54:47.000 |
| 4764 | 2023.1.00815.S | 0 | Deep [CII] observations of a radio galaxy at z=5.72: insights into AGN feedback | We propose to ALMA obervations to study jet-gas interactions using the [CII] line in the most distant radio galaxy currently known, TGSS J1530+1049 at z=5.72. Our objective is to spatially resolve the [C II] emission and study AGN feedback in the early Universe by investigating gas kinematics induced by powerful radio jets. A key advantage of using radio galaxies for such studies instead of quasars is that their AGN jets are aligned along the plane of the sky and are spatially resolved. We will also map the distribution of dust and measure its temperature. Being the brightest radio source at z>5.5, this target presents a unique opportunity to study AGN feedback in the early Universe, which leads to quenching of massive galaxies. The target benefits from existing mm/sub-mm observations giving a reliable measure of the FIR continuum and expected [CII] flux. We propose observations with a resolution of 0.2"-0.3" to spatially resolve [CII] over ~10 beams, with a S/N>5 per beam, in a total time of 12 hours. ALMA observations investigating AGN feedback will be aided by existing high-resolution radio VLBI and incoming HST and VLT/MUSE observations, as well as approved JWST programs. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 3000-01-01T00:00:00.000 |
| 4765 | 2022.1.01077.L | 214 | A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE): A Quasar Legacy Redshift Survey | We propose to obtain deep ALMA 1.2mm mosaic observations around 25 luminous z~7 quasars. These quasar fields will be covered by multi-band JWST imaging and 3-4 um slitless spectroscopy to identify star-forming galaxies at 1 | Sub-mm Galaxies (SMG), High-z Active Galactic Nuclei (AGN) | Galaxy evolution | 2024-01-26T21:52:57.000 |
| 4766 | 2015.1.00274.S | 46 | A Close Look into the Blast Furnace: the Core of the NGC253 Starburst at One Parsec Resolution | We propose to image the central region of NGC 253 at unprecedented 1.6 pc resolution with excellent brightness sensitivity in molecular gas, dense gas, and dust continuum to push forward our understanding of the processes that regulate star formation on cluster scales in a starburst environment. We will measure luminosities, sizes, and velocity dispersions on molecular condensations down to sizes of 1-2 pc, and compare them to the Milky Way CMZ. We will obtain dust/dynamical masses and densities for protocluster-size concentrations, measure their mass spectrum, determine local dynamical timescales, and search for the signatures of the transition from the "slow, low efficiency" regime of star formation seen on large scales to a "fast, high efficiency" regime on small scales. We will study feedback signatures, in particular we will look for the imprint of strong radiative feedback by estimating FIR optical depths from dust surface brightness, measuring local kinematics with high S/N line profiles, measuring the detailed acceleration of cloudlets, and observing the launching of the molecular outflow. NGC 253 is the best source to carry out these high spatial resolution observations. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2018-04-22T04:25:17.000 |
| 4767 | 2015.1.00926.S | 227 | Direct Emission from Advection Dominated Accretion Flows in the Local Universe | The central engines in "mechanical mode" AGN are powered by radiatively inefficient Advection Dominated Accretion Flows (ADAFs). However, emission expected to be directly associated with an ADAF around a super-massive black hole has only thus far been detected in Sgr A* and the recently discovered strong ADAF candidate in NGC5044. Here we propose poor-weather observations in bands 3 & 4 of a sample of 7 nearby ellipticals that have weak cm-wave radio powers and low, well-constrained dust emission. They all host radiatively inefficient AGN, and are hence strong ADAF candidate systems in which to observe the (sub-)mm bump that is postulated to arise due to hot synchrotron self-absorbed electrons in the accretion flow itself. | Galactic centres/nuclei | Active galaxies | 2018-05-24T17:12:58.000 |
| 4768 | 2017.1.00072.S | 4 | How much do the cool components of solar X-ray jets contribute to the fast solar wind? | Understanding of the solar wind is critical not just for space weather forecasting, but also for investigating the physical processes by which stellar winds affect mass loss and stellar evolution in the broader astrophysical context. Polar coronal holes are an important source of fast solar wind. X-ray observations with the Hinode satellite have shown that solar X-ray jets frequently occur in polar coronal holes, and they are garnering attention because they might supply material to, and drive disturbances in, the fast solar wind. Recently, it has been found that most of solar X-ray jets are associated with the eruption of small filaments composed of relatively cool plasma. This raises the possibility erupting filaments supply a significant amount of mass to the fast solar wind. We have developed a method for estimating the mass of cool plasma from the data in mm-wave/EUV/X-rays emission and have succeeded in obtaining the mass of cool plasma erupted from an X-ray bright point. Here we request ALMA observations of solar X-ray jets in polar coronal holes in order to estimate the mass contributed by associated cool erupting filaments to the fast solar wind. | The Sun | Sun | 2019-08-27T20:25:00.000 |
| 4769 | 2015.1.00141.S | 9 | Kinematics of the incipient bipolar nebula of L2 Puppis | The final stages of stellar evolution involve fascinating physics, complex chemistry and spectacular structures (disks, planetary nebulae,...). The red giant L2 Pup is likely experiencing the early stages of the formation of a planetary nebula. Its remarkable proximity (64pc) makes it the second nearest AGB star. VLT adaptive optics images revealed a dust disk seen almost edge-on, a close-in companion and a compact bipolar structure. But these encouraging results remain qualitative. We do not know the exact evolutionary state of the central AGB star, neither its mass, and our interpretation in terms of bipolar structure is currently based on its visible morphology only. We will use ALMA to determine the stellar mass and the geometry of mass loss. Our first science goal is to measure the rotation profile of the disk from the CO(3-2) line to derive the mass of the central stars. This will enable us to pinpoint the evolutionary state of the AGB. Our second goal aims at testing the bipolarity hypothesis, by mapping the velocity structure of the extended wind in the CO(2-1) line. L2 Pup offers a unique vantage point on the disk-wind interaction. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2017-05-19T20:54:53.000 |
| 4770 | 2022.1.01348.S | 72 | An ALMA Study of Hidden Dual AGN in Nearby Post-Mergers | Major galaxy mergers are thought to play an important role in fueling supermassive Black Hole growth. However, observational support for this hypothesis is mixed. Using high-resolution NIR imaging of nearby hard X-ray selected AGN from the Swift BAT sample, a hidden population of late-stage nuclear mergers (<3 kpc) among luminous obscured AGN was found showing post-merger features. The closest among these was found to host the closest dual AGN resolved using multiwavelength data at 220 pc (0.3) with two compact continuum sources in ALMA. This compact emission component has been found in other close dual AGN (e.g. NGC 6240). Hence, the sub-mm continuum emission can be used as a revolutionary and unmatched technique to unveil previously-missed dual AGN in hidden mergers at very close nuclear separations. We propose the first high resolution 100 Ghz continuum ALMA dual AGN survey of post-mergers in luminous nearby AGN (z<0.05) to search for hidden dual AGN down to the black hole sphere of influence (<50 pc). These 12 AGN, never before studied with submillimeter at <1 scales, will provide the first test of post-mergers hosting possible hidden dual AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2024-08-22T14:04:10.000 |
| 4771 | 2018.1.01103.S | 82 | Resolving the ISM properties and circumnuclear starburst of a Quasar Host at z=4.4. | The z=4.4 quasar BRI 1335-0417 provides the unique opportunity to study the ISM of a quasar host galaxy in unprecedented detail. Our high-quality, 0.2" (~1kpc) resolution imaging of the CO(2-1), [CII] and continuum emission reveal a galaxy with a dynamically complex molecular gas, an extended [CII] disk resembling a warped disk and a cuspy continuum emission. Here we propose 0.06" observations of [CII] and continuum to reveal the conditions of the circumnuclear starburst discovered in cycle 5. The ~400 pc resolution observations will provide an unparalleled view of the gas in star-forming regions where the gravitational and feedback effects by the AGN dominate. We will complement the already obtained data with a set of 6 new emission lines observations. The CO lines (J=7 and J=12), the fine structure lines ([OIII] and [NII]), the water line and the underlying continuum between 88 and 370 microns rest frame will return key information about the ISM conditions over multiple regions. The emission lines will reveal the excitation conditions of molecular gas, the extension and level of ionized medium, as well as the molecular and atomic outflows. | Starburst galaxies, High-z Active Galactic Nuclei (AGN) | Active galaxies | 2020-08-23T09:34:48.000 |
| 4772 | 2017.1.01307.S | 15 | Collisional star-formation in the SMC: NGC346 | The NGC346 open cluster, and the entire HII region N66, are clearly exceptional in the context of the ensemble of otherwise rather benign star-forming regions in the SMC. Accounting for 6% of the total current-era star-formation within the SMC, NGC 346 harbours upwards of 30 O-type stars; more than half the entire SMC O-star population, as well as a number of young stellar objects and pre-main sequence objects. We propose here mapped observations of the molecular clouds associated with N66, at the 1-0 and 2-1 transitions of both 12CO and 13CO. Following existing techniques in the literatue, these data will be sufficient to derive a usefully-constrained solution to the Radiative transfer equations, and yield resolved maps of both the excitation temperature and molecular cloud number density}. We will then have sufficient information to determine the energy density within the cloud population. The measured energy density larger will be contrasted with that typically associated with cold and dense molecular clouds (30K, and No~10^4 cm^-3) where a significant excess would suggest a evolution involving a kinetic, filament-filament interaction. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-11-09T00:00:00.000 |
| 4773 | 2016.1.01559.S | 32 | Resolved Kennicutt-Schmidt law at z~0.3 | We propose to conduct the first measurement of a spatially resolved Kennicutt-Schmidt law at z~0.3, when the Universe was 75% its current age. Our target sample of 3 luminous infrared galaxies were detected in ALMA Cycle 1 observations. We propose high resolution CO(3-2) emission line observations with ALMA to trace the molecular gas surface density. We trace star foramtion using new high resolution 3 GHz data taken as part of the VLA COSMOS survey. Our proposed observations will also result in resolved kinematics and dust continuum measurements allowing us to independently constrain the CO-to-H2 conversion factor. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2018-03-21T17:12:39.000 |
| 4774 | 2013.1.00994.S | 0 | Resolving polarization holes in W51 | Magnetic fields are one of the key parameters in star formation theories. Major obstacles in advancing our understanding of magnetic fields are the difficulty of obtaining higher-resolution maps of field morphologies together with the difficulty of accurately measuring the field strength. We propose Band-6 0.2"-resolution dust polarization continuum observations in order to resolve polarization holes in several cores in W51 that we previously observed with the SMA. Polarization holes are often a signpost for complex underlying field structures that remain hidden in coarse resolution. As revealed from line observations, our targeted zones very likely host rotating structures. The science goals of this proposal are: (1) resolving magnetic field morphologies in rotating/accreting structures and (2) measuring the local field strength in the inner core regions in order to constrain field strength profiles and magnetic flux removal processes like ambipolar diffusion. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2017-12-22T00:00:00.000 |
| 4775 | 2022.1.01487.S | 717 | ACA Monitoring of Event Horizon Telescope (EHT) targets during the April 2023 EHT Campaign | The Event Horizon Telescope (EHT) observations will be carried out in Cycle 9, with the aim of resolving black hole shadows and jet launching regions in AGNs. These are expected to be observed over a 12-day period in March-April 2023, using several ~5-15 hr observing runs, triggered based on weather and telescope readiness, i.e. individual sources will be observed over several days with unpredictable gaps in daily coverage. Here, we propose daily ACA monitoring of four sources: SgrA*, M87, 3C279, and CenA - during the 2023 EHT campaign. The primary goals of this proposal are to obtain: (a) better than 10% absolute flux calibration (per daily epoch) for all sources in the EHT observing runs (via bootstrapping); (b) constrain the origin of variability (e.g. proper motions vs relative brightening of individual components, or hot-spot orbits in Sgr A*) seen in EHT images on individual days using the argument of spectral variability; (c) a better comparison with the multi-wavelength (cm to X-ray) campaign (EHT private communication). Overall, these observations will lead to a significantly better, and perhaps crucial, understanding of the physical mechanisms on event horizon scales. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2024-05-03T11:18:56.000 |
| 4776 | 2021.1.00822.S | 9 | Towards unraveling the puzzle of 15N-enrichments in comets | The ratio of the two stable nitrogen isotopes, 14N/15N, varies by almost an order of magnitude among the solar system bodies and thus represents a distinct fingerprint with enormous potential for constraining the origin of planetary and cometary building blocks. However, nitrogen isotope fractionation during star formation is still poorly understood. One of the central obstacles is that the 14N/15N of N2, the main nitrogen reservoir, cannot be measured directly and indirect measurements from N2H+ and NH3 do not give a consistent picture. Recently, the spectroscopy became available for the 15N-isotoplogues of NH and NH2, the two neutral molecules most closely linked to N2. This proposal aims at the first detection of 15NH and 15NH2 and at measuring their 14N/15N ratios towards the low-mass protostar IRAS 16293-2422. By providing stringent constraints on the 14N/15N in N2 and comparing with previously measured species belonging to the atomic nitrogen reservoir, the proposed observations will shed light on whether there are in fact two different nitrogen isotopic reservoirs in star-forming regions, or just a single one as indicated by the homogeneous 14N/15N ratios in comets. | Low-mass star formation, Astrochemistry | ISM and star formation | 2023-05-11T21:26:19.000 |
| 4777 | 2016.2.00168.S | 25 | The Circumstellar Disk of a Vigorously Accreting FUor | We will carry out Band 6 ACA dust continuum and CO observations of Z CMa, a binary system composed of an embedded Herbig Be star and an FU Ori object. In cycle 4 we proposed Band 6 observations of Z CMa (2016.1.00110.S; PI: R. Dong) with 0".05 angular resolution to look for spiral arms and large scale asymmetries as revealed by our Subaru scattered light observations (Liu et al. 2016) and predicted in our gravitationally unstable disk models for FU Ori objects (Dong et al. 2016). Our program has been approved and partially executed. Upon inspecting the delivered low resolution data (~0".2 resolution), we found significant missing flux in the gas observations. To complement existing 12m-array observations and thereby maximize the science return, we request ACA observations of Z CMa to supply uv sampling at short uv distances. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2018-10-09T07:31:37.000 |
| 4778 | 2021.1.00403.S | 8 | The Origin of Warm Debris in Two-Temperature Debris Disks: Asteroidal or Cometary? | We propose a deep ALMA map at subarcsecond resolution to reveal the source region of the inner debris around Fomalhaut. The proposed observation will provide an answer to the long debate -- asteroidal vs. cometary -- for the origin of warm dust in ~20-30% of the known debris disks. Millimeter observations are the only means to unambiguously detect and characterize the detailed structure of a planetesimal belt, which bears the imprint from terrestrial and ice-giant planets that are undetectable directly with current techniques around Fomalhaut. If the warm debris arises from the collisional cascades of remnant planetesimals near the snowline, the region of mm emission should manifest as a narrow ring. Imaging such a planetesimal belt near the snowline around a mature exoplanetary system would be a breakthrough in understanding the formation and evolution of exoplanetary systems in general. If the source region is found to be broad, the warm debris likely arises from disintegrating comets scattered inward by a chain of low-mass planets. The proposed observation would provide a better constraint on the rate of cometary delivery for the planetesimal scattering theory. | Debris disks | Disks and planet formation | 2023-10-11T21:29:45.000 |
| 4779 | 2023.1.01292.S | 0 | A sub-mm census of a very massive and old quiescent galaxy at z=3.19 | We propose to use ALMA to target a unique newly confirmed z>3 massive quiescent galaxy. The galaxy ZF-UDS-7329 is revealed by JWST NIRSPEC to be at a spectroscopic redshift of 3.19. It has a stellar mass of 3E11 M_sun and a very red, unobscured, spectrum with a well developed 4000Å break, in contrast to the younger Balmer break seen in other z>3 massive quiescent galaxies. The JWST spectrum is extremely well fit by a stellar population of age 1.5 Gyr, i.e forming at very rapidly at z~11. ZF-UDS-7329 is 2-3x older than other massive quiescent galaxies at z>3 and quenched very rapidly in to a very compact red disk early in cosmic history. With ALMA we will probe for obscured star-formation (Band 7 dust continuum) and molecular gas (Band 3 CO(4-3)). Combining these measurements with the star-formation history reconstructed from the NIRSPEC spectra we can see if the physical mechanisms underpinning the formation of this remarkable object are different from the normal quiescent galaxies at z>3. | Galaxy structure & evolution | Galaxy evolution | 2025-09-12T13:18:19.000 |
| 4780 | 2021.1.00869.L | 13954 | Bulge symmetry or not? The hidden dynamics of the Far Side | A radio survey of red giant SiO sources in the inner Galaxy and Bulge is not hindered by extinction. Extremely accurate stellar velocities (<1 km/s) are obtained with minimal observing time (<<1 min) per source. Our aim to collect 20000 SiO maser velocities yields data comparable to optical surveys with the additional strength of a much more thorough coverage of the highly obscured inner Galaxy and Plane. Large samples reveal dynamical structures and minority populations, and their velocity structure may be compared with kinematics of molecular gas, complex orbits in the bar, or stellar streams resulting from recently captured systems. From existing data we collected ~12000 stellar velocities, almost exclusively in the northern Bulge. ALMA is the only instrument that can efficiently add measurements to the undersampled southern Bulge region (-11070% detection rate). We propose to use ALMA to survey 6000 sources in ~120h to obtain 4200+ data points in the undersampled Southern Bulge as part of this larger NSF-funded proposal. | Spiral galaxies, Galactic centres/nuclei | Local Universe | 2023-02-04T10:55:14.000 |
| 4781 | 2012.1.00501.S | 2 | The Coldest Object in the Universe: Probing the Mass Distribution of the Ultra-Cold Outflow and Dusty Disk in the Boomerang Nebula | Our Cycle 0 ALMA observations confirm that the Boomerang Nebula is the coldest known object in the Universe, with a massive high-speed outflow that has cooled significantly below the temperature of the cosmic background (CMB). We now propose follow-up observations to study the origin and evolution of this remarkable phenomenon. Our 2-4 arcsec resolution Cycle 0 data show an outer roughly spherical structure with patchy regions of ultra-cold gas but the envelope proves to be more extended than we expected, and comparison with single dish observations indicates that the ALMA data represent only 10-15 % of the envelope mass. We also find a dusty hourglass-shaped warm inner outflow with a dense central waist (completely unlike the ultra-cold outflow), that provides a natural explanation for the overall bipolar shape of the nebula seen in HST images. The Boomerang's prodigious mass-loss rate (0.001 solar masses/year) and low-luminosity (300 Lsun) make it a key object for understanding the remarkable transition of the circumstellar envelopes of AGB stars into bipolar planetary nebulae. We will observe the ultra-cold outflow with the 12-m Array and ACA to fully recover the morphology of the cold gas, essential for understanding the physics involved in the formation of this nebula. The hypothesis that the gas is super-cooled by expansion suggests that it should be reheated in the outer regions. The data in hand provide evidence for such a transition, but the full map of the mass distribution and kinetic structure is essential to quantitatively constrain reheating mechanisms. We will also obtain high-resolution (0.4 arcsec) images in CO J=3-2 emission in order to isolate a central disk/torus structure expected as a result of the binary interaction that has been theorized to explain the formation of bipolar PNe. The Cycle0 1.3 and 2.6 mm continuum data suggest the presence of very large (mm-sized) grains in the central region: we now propose to obtain 3.5 mm continuum observations to comfirm this result and set robust constraints on the grain size distribution. | Post-AGB stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2015-03-20T17:52:18.000 |
| 4782 | 2023.1.01703.S | 0 | Monitoring Giant Planet High-Altitude Jet Streams | The upper atmospheres of Jupiter and Saturn display remarkable variability from jet streams that evolve over non-seasonal timescales and influence their surrounding environments. Data acquired over multiple decades have revealed patterns in stratospheric temperatures that can be explained as the interaction of waves produced from convection and their impact on the changes in speeds of equatorial winds. Inspired from a terrestrial analogue, theories and models have been developed to better understand how each phenomenon compares to its counterparts in other planets, and how they can each be perturbed by large-scale weather events also. The initial step in understanding outlier data in any system is to first characterize its properties, recognizing trends and measuring its natural variability over appropriate timescales to properly contextualize anomalous behavior. We propose an ambitious observational campaign utilizing the ACA to create a record of stratospheric wind measurements for Jupiter and Saturn to investigate the dynamical impacts of processes and events operating different timescales. | Solar system - Planetary atmospheres | Solar system | 2025-06-18T20:49:56.000 |
| 4783 | 2017.1.00191.S | 17 | Studying the inner circumstellar envelope of AGB stars using ALMA and SPHERE | We propose to study the mass-loss process experienced by low- and intermediate-mass stars at the end of their lives using quasi-simultaneous ALMA and SPHERE/ZIMPOL observations of two AGB stars. These data will spatially-resolve the stellar disc at visible and sub-mm wavelengths. Moreover, the ZIMPOL images of polarised light will reveal the distribution of the dust grains that drive the outflow and the ALMA observations will probe the gas in the innermost regions of the circumstellar envelope. Comparing the stellar disc at these very different wavelengths will provide unprecedented insight into the processes shaping the star and leading to the outflow, such as convective motions, shocks, and even magnetic activity. The combined analysis of the density distributions of gas and dust at high spatial resolution will significantly advance our understanding of the dust formation process and of the wind-driving process. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2019-01-27T10:58:43.000 |
| 4784 | 2015.1.01273.S | 32 | Investigating the origin of the IMF and constraining SFR models in the W43-MM1 mini-starbust ridge | Studying extreme protoclusters is necessary to test if the IMF origin and SFE can be independent of cloud local characteristics. The W43-MM1 ridge, being extreme in terms of cloud concentration and star formation activity, is a case-study to confront star formation models. It consists of a very dense and cold mass reservoir of 20 000 Msun. We discovered that it hosts a cluster of 11 massive dense cores. With untested assumptions regarding the fragmentation of massive dense cores into protostars and the shape of the stellar IMF, we expect more than 2000 stars to form, with a SFR of 6000 Msun/Myr reminiscent of starburst galaxies. A preliminary study of the mass distribution in the W43-MM1 mini-starburst ridge suggests that statistical SFR models do not apply to ridge clouds. We propose to investigate the fragmentation of W43-MM1, down to the now well-defined protostellar size of 2000 AU. We especially want to 1) look for protostars and prestellar cores able to form early O-type stars, 2) define the size/density inside/above which the core mass function does not mimic the IMF anymore, and 3) accurately measure the SFE correlation to the cloud density and turbulence level. | High-mass star formation, Low-mass star formation | ISM and star formation | 3000-01-01T00:00:00.000 |
| 4785 | 2021.2.00059.S | 20 | Feeding BEARS at Cosmic Noon | Cosmic Noon (redshift z~2), when the Universe was 3 Gyr old, is when the volume-averaged star formation (SF) density in the Universe peaked, when most of the Universe's metals were created, and when the supermassive black hole growth reached its maximum. This epoch was radically different to today. Ultraluminous galaxies (ULIRGs, >1e12 Lsun) were part of the "main sequence" of sustained star formation, whereas at z=0 they are negligible for the SF budget and exist in "starburst" (ie intermittent) mode. Sub-millimetre galaxies (SMGs) at Cosmic Noon contributed tens of percent to the overall cosmic SF. We reanalysed Herschel SMG redshift campaigns from cycles 4-7, now public, which we refer to as the Bright Extragalactic ALMA Redshift Survey (BEARS). These are the brightest SMGs at Cosmic Noon and the best examples to illuminate the triggering & fuelling of SF. We have 25 z~2 SMGs with CI 492GHz measurements and request ACA band 6 data of gas masses (via CI 809GHz) and star formation rates (SFRs, via H2O) to measure: molecular gas fuel; gas consumption timescales; AGN heating; positions relative to the main sequence - all testing for drivers & triggers of SMG SF at its peak. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2023-08-22T15:38:00.000 |
| 4786 | 2015.1.01503.S | 19 | Testing the Correlation of Class 0 Disks with Aligned Magnetic Field and Rotation Axes | Circumstellar disks are a crucial ingredient for star formation. However, there is debate about whether the youngest protostars, Class 0 objects, commonly have large disks. Recent observations show a trend: large (R>30 AU) disks occur if their magnetic fields are perpendicular to their rotation axes. Sources with a parallel magnetic field do not have detectable disks down to R~15 AU scales, consitent with the thought that, with this alignment, material infalling to the protostar loses angular momentum to the magnetic field, and that this inhibits disk growth early on. Though the trend is suggestive, only 7 Class 0 objects have had their magnetic field orientation and disk structures compared; more examples are needed to confirm. The VANDAM survey observed 73 objects in centimeter-wave dust continuum with the VLA, which yielded seven new disk candidates. Kinematic observations of these will be done with the SMA to confirm Keplerian rotation. High resolution polarization ALMA observations of four of these, plus seven more without detected disks, will allow us to map their inferred magnetic field and start to build a significant sample of magnetic field alignment of Class 0 objects. | Low-mass star formation | ISM and star formation | 2018-02-14T21:32:44.000 |
| 4787 | 2011.0.00611.S | 0 | Detecting high-density compact outflow from the youngest YSO in Taurus | Recent theoretical simulations show that low-velocity flows of ~5km/s are driven from the adiabatic protostellar core (the first core), and that most of the initial angular momentum of the natal dense cores has been transferred during this stage. It is therefore of vital importance to investigate the first core objects as well as the outflow at this stage. In this proposal, we will carry out ALMA observations toward a dense core that contains the youngest protostar in Taurus, MC27 or L1521F in the lines of HCO+(3-2) and HCN(3-2) with multiple pointings, and in the lines of H13CO+(3-2), CS(5-4), and SiO(6-5) with a single pointing. The CSO observation in HCO+(3-2) showed that compact outflow wing is clearly seen only at the center pointing, and we found that this is due to the existence of high-density compact outflow originated from the central source. The proposed observation will be able to investigate the physical properties of the “very young” outflow, giving us invaluable information to solve how the initial angular momentum is distributed during the phase observationally. | Pre-stellar cores, Infra-Red Dark Clouds (IRDC), Low-mass star formation | ISM and star formation | 2014-03-07T02:20:00.000 |
| 4788 | 2017.1.00994.S | 65 | Spectral line survey toward a hot molecular core in the Large Magellanic Cloud | Because cosmic metallicity is increasing in time with the evolution of our universe, interstellar chemistry in low metallicity environments is crucial to understand chemical processes in the past metal-poor universe. Based on our ALMA Cycle 1 program, we have identified a hot molecular core in a nearby low metallicity galaxy, the Large Magellanic Cloud. The ALMA data suggests that the molecular abundances of the LMC hot core are significantly different from those of Galactic hot cores. The LMC hot core provide us great opportunities to investigate chemical compositions of complex organic molecules in low metallicity environments. However, since only limited spectral regions were observed during Cycle 1, the detailed chemical compositions of the LMC hot core still remain to be investigated. Here we propose an unbiased spectral line survey toward the LMC hot core in the 333-364 GHz region. A goal of this program is to unveil chemical compositions of a hot molecular core in the LMC, particularly focusing on chemistry of complex organic molecules, and to understand them in relation to the characteristic low metallicity environment. | Astrochemistry, Magellanic Clouds | ISM and star formation | 2019-12-20T13:48:40.000 |
| 4789 | 2018.1.00336.S | 32 | Peering closely at stellar-merger sites | Red novae erupt in stellar collisions which we can observe in real time. Although rare, they give us a chance to investigate the physics of the most extreme form of binary interaction. Using ALMA and SMA, we recently found that cool remnants of red novae are sources of rich molecular emission at submillimeter wavelengths. The molecular gas traces material that was dispersed in the merger event. We propose to use ALMA to spatially resolve molecular emission in two red nova remnants, V1309 Sco and V838 Mon, and reproduce their 3-dimensional spatio-kinematic structure. With a clear view on the two merger sites, we aim (1) to decode the geometry of the merged systems, (2) measure the energy of the merger eruption, and (3) follow the angular momentum transfer that had driven the spiraling-in and the coalescence of the binaries. These observational constraints are essential to advance our understanding of why and how stars merge. | Transients | Stars and stellar evolution | 2021-01-02T22:10:13.000 |
| 4790 | 2016.1.00654.S | 285 | [NII] 205 um at z~3-5.7 | We propose to observe the [NII]205 micron transition in 16 dusty star forming galaxies previously detected in low or mid-J CO and the [CII]158 micron line and distributed at redshifts z~3-5.7. The [NII]205 line is a sensitive tracer of ionized gas, and complements the [CII] line as a star formation diagnostic. We will use the [NII] line to measure the ionized gas mass, characterize the ionizing source (as O stars or B stars), and we will use the [NII]/[CII] ratio to determine how much of the measured [CII] arises from ionized rather than neutral gas - a crucial parameter for interpreting current and future [CII] surveys. Our observations will dramatically increase the number of [NII] detections at high redshift. This project complements the work of our (ongoing) A-ranked, cycle 3 project to characterize [NII] in z~1-2 galaxies. This addition to our [NII] campaign allows a unique look at star formation, tracing trends in [NII] throughout the epochs of peak star formation and galaxy assembly. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 2019-05-18T00:51:16.000 |
| 4791 | 2013.1.01086.S | 4 | Physical Properties in ``Hot'' Rings around Protostars | We propose the ALMA Cycle 2 observations toward three protostars to reveal the physical properties in ``hot'' ring regions. ALMA Cycle 0 observations with the angular resolution of 0.8 arcsec have revealed that SO emission shows PV diagram, which is explained by rotating ring. This feature is quite different from that of C18O emission, which shows Keplerian rotation at the innermost region. The SO molecules might be heated above the sublimation temperature by accretion shock. In the ALMA Cycle 2, we will observe three transitional lines of SO emission in Band 6 and 7, which allow us to perform LVG calculations to investigate the physical properties in the hot ring region. We can distinguish the hot ring from other region with the angular resolution of 0.2 arcsec. We will also observe C18O lines to derive column density toward these regions. C18O also provide the measurements of Keplerian rotation with better resolution. If the hot rings are actually in shock condition, it will be the first example for directly imaging the accretion shock region. ALMA Cycle 2 observations are the first opportunity for approaching the detailed physical conditions in protostellar envelopes. | Disks around low-mass stars | Disks and planet formation | 2016-12-04T07:54:20.000 |
| 4792 | 2019.1.01529.S | 323 | The Third Leg of Galaxy Stellar Mass Assembly: A Census of CO in high-redshift cluster centrals | We are undertaking a multi-faceted study of the in-situ stellar mass growth of Brightest Cluster Galaxies through cosmic time. These systems are the most massive galaxies at any epoch and form at the dense centres of galaxy clusters. Once thought to be outliers, they are now recognized as sensitive probes of hierarchical structure formation processes such as gas cooling, galaxy merging and energy feedback mechanisms. Coupling the Spitzer Adaptation of the Red-Sequence Cluster Survey to the OzDES spectroscopic survey, we have assembled the largest sample of spectroscopically confirmed BCGs beyond z>0.3 to date. We are now engaged in an campaign to measure the three fundamental characteristics of galaxy mass assembly for these BCGs: the current stellar mass, the instantaneous star formation rate and,here, the total molecular gas mass available for new stars. This three-pronged approach will elucidate the growth of BCGs and provide constraints for models which currently struggle to reproduce their observed properties over time. The first two prongs of this study are in hand; we now request 15hrs in ALMA Cycle 7 to assemble the first census of molecular gas (CO(2-1)) in high-z BCGs. | Galaxy structure & evolution, Galaxy Clusters | Galaxy evolution | 2021-03-13T14:06:42.000 |
| 4793 | 2017.1.00969.S | 22 | Detecting a circumplanetary disk in a young binary system | Direct imaging has discovered a number of substellar companions to date, located at large separation of 10s or 100s of au. The processes of their formation are not well understood, because at these separations, their formation timescale is much larger than the typical disk dissipation time. Most of the detected substellar companions are located in old systems where we can only study the second generation dust in the form of debris belts. We recently detected for the first time a few Jupiter-mass planet outside of a resolved gaseous disk around CS Cha, a young (2 Myr-old) binary system. The circumbinary disk also hosts an inner cavity, qualifying the system as a transition disk. In addition, we found that the signal at the planet location appears highly polarized indicating the presence of dust in a circumplanetary disk. In this proposal, we aim to observe both the circumbinary and the circumplanetary disks in the sub-millimeter regime, to derive the circumplanetary disk dust mass, and to characterize the circumbinary disk in terms of spatial extent, cavity size, gas kinematics and dust mass. This will allow us to better constrain the processes of planet formation in CS Cha. | Disks around low-mass stars | Disks and planet formation | 2019-05-10T00:00:00.000 |
| 4794 | 2023.A.00038.T | 0 | Pre- and Post-Burst Observations of the recurring Nova T CrB | Nova outbursts result from the thermonuclear runaway in the accreted envelope of white dwarf in a binary system. Symbiotic Recurrent Novae (SyRN) are a distinctive class with more massive white dwarfs and/or higher accretion rates than classical novae, hence possible progenitors of Type Ia supernovae. Understanding these outbursts requires time-resolved multi-wavelength SEDs to trace the ejecta moving within the giant companion's wind and dense circumstellar medium, accelerating protons and electrons to GeV and higher energies, and driving a shock with Mach numbers in the hundreds. T CrB is the nearest recurrent nova and a SyRN. It is predicted to erupt before the end of 2024. A large international collaboration is set to panchromatically (radio through Gamma rays) follow this event in an unprecedented way -- this proposal covers the mm/sub-mm regime. While the ejecta are optically thick at longer wavelengths, sub-mm observations probe the inner ejecta and shock dynamics and structure at earliest stages of outburst. We propose a pre-outburst snapshot with ALMA and a sequence of visits in outburst to follow the early evolution of the ejecta in (sub)mm continuum emission. | White dwarfs, Transients | Stars and stellar evolution | 2025-04-01T08:15:26.000 |
| 4795 | 2017.1.00413.S | 73 | Spatially resolved kinematics and SFRs of direct progenitors of compact quiescent galaxies at z = 2 | The discovery of the "red nugget" population (massive, compact, quiescent galaxies) at z = 2 indicates that early passive galaxies were remarkably compact compared to their present-day elliptical counterparts. Recent HST observations have identified a likely population of progenitors: similarly massive and compact galaxies that are dusty and star-forming. While several pieces of indirect evidence link these two populations, resolution and sensitivity limitations in optical/NIR observations prevent a direct confirmation. Only the unique capabilities of ALMA in the FIR can provide definitive confirmation of this evolutionary connection. We propose to obtain high spatial resolution (FWHM=0.14'') CO and [CI] velocity maps, and 1.2 mm continuum observations on 4 dusty, compact SFGs at z~2 to answer the following questions: a) what are the kinematic properties of their molecular gas? (ordered rotation vs. large dispersion), b) is the molecular gas profile as compact as the stellar mass and SFR sizes (FWHM=0.2'' and 0.14''), c) do they have short quenching (gas depletion) timescales consistent with the rapid build up the quiescent population at z = 2?. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2019-01-24T14:29:40.000 |
| 4796 | 2017.1.00899.S | 56 | Constraining the Interstellar Medium Properties of the Most Luminous Galaxy in the Universe | At a redshift of 4.601 and with a luminosity of Lbol = 3.5 x 10^14 Lsun, WISE J22460526 (W2246 hereafter) is the most luminous galaxy in the Universe detected to date. Cycle 2 ALMA observations of the [CII]158um emission line have revealed a strikingly uniform and highly turbulent interstellar medium (ISM) that is being blown away from the host galaxy isotropically. This is likely being driven by the energy and momentum injected by the central hyper-luminous super-massive black hole into the surrounding gas. The ISM properties of this outstanding galaxy, however, are still barely known. Here we propose to obtain ALMA bands 7, 8 and 10 observations of W2246 in the [OI]145um, [NII]122um and [OI]63um emission lines, respectively, at an angular resolution similar to that of our [CII] data, ~0.35". The goal of this project is to use this suit of far-infrared lines to characterize the properties of the gas -such as its density and kinematic temperature- in a galaxy that represents the ultimate laboratory for studying and model the ISM properties and kinematics under strong feedback. | High-z Active Galactic Nuclei (AGN), Galaxy structure & evolution | Active galaxies | 2019-06-13T15:11:52.000 |
| 4797 | 2016.1.00026.S | 92 | Mapping the wind structure and kinematics of the AGB star EP Aqr | EP Aqr is one of the nearest mass losing AGB stars, for which previous data show a bipolar outflow observed almost pole on, in addition to evidence of discrete shells in the circumstellar envelope. ALMA will be used to reveal the 3D structure of the circumstellar shell and resolve the close environment of the central star where the wind is accelerated and where the bipolar outflow is initiated. The high quality of the imaging in the CO (1-0) and (2-1) lines will provide a global description connecting the inner and outer regions of the envelope, and will allow us to perform a quantitative comparison with the models that we have already prepared. We propose to use the 12-m Array (with baselines up to 2 km) to observe EP Aqr in band 3 with a 3-point mosaic for a total of 2.8h, and in band 6 with a 10-point mosaic for a total of 1.5h. In addition, ACA will be used to recover short spacings in band 6 (1.6h). Furthermore, we request, a single pointing in band 6 with an extended configuration of the 12-m Array (1.5h). We will thus be able to connect the different regions of the stellar wind of this proto-typical semi-regular variable, allowing us to get a global picture of the outflow. | Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2018-05-11T04:59:20.000 |
| 4798 | 2021.2.00056.S | 0 | Panta Rei: the mass and energy flow from parsec to sub-parsec scales in star-forming regions | The Panta Rei project aims to understand the dynamics in massive star-forming regions by investigating the interplay between turbulence and gravity at the parsec and sub-parsec scales. Whether the flow of mass and energy at various spatial scales is driven by the turbulent cascade or by gravitationally ordered motions is still highly debated, with a crucial question still open: is gravity the leading mechanism to assemble material already at large scales, as predicted in theories such as the hierarchical, global collapse (Vazquez-Semadeni et al. 2019), or is it turbulence that drives the fragmentation at parsec and sub-parsec scales, as predicted in models such as the inertial inflow (Padoan et al. 2020)? We propose to observe with ACA and TP arrays 20 sources and their parsec-scale environments with a combination of optically thin and optically thick lines that together will unequivocally prove the nature of the multi-scale motions and direct us towards the understanding of the massive star-formation mechanism. | High-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2024-06-07T00:00:00.000 |
| 4799 | 2016.1.01511.S | 222 | A Complete Survey of Disk Masses, Sizes, and Particle Growth across the Stellar/Substellar Transition | Combining the high sensitivity and angular resolution of ALMA with an optimal target set based on our Herschel Taurus Boundary of Stellar/Substellar (TBOSS) survey, we propose to measure the disk masses, radii, and spectral indices for a complete sample of Herschel-detected low mass stars and brown dwarfs. Based on our previous ALMA pilot study of a subset of the targets which yielded a 100 per-cent detection rate, this efficient approach will enable a full population study of disk properties that critically impact planet formation. The proposed program has three main science goals: (1) determine the dust and gas disk sizes and disk masses from Band 7 observations of Herschel-detected TBOSS members, (2) search for evidence of grain growth in the spectral indices of Band 7 and Band 3 observations, and (3) conduct a pilot study of a control sample of Herschel non-detections to compare the complete sample with more evolved disks. The proposed Cycle 4 project, in conjunction with our previous program, will investigate over 50 disks with spectral types of M4 and later, providing a benchmark data set to answer key questions in star and planet formation. | Disks around low-mass stars | Disks and planet formation | 2018-07-22T11:48:24.000 |
| 4800 | 2017.1.01499.S | 28 | LiH - a probe of Galactic Li evolution and the lithium problems | Li abundances of Big Bang Nucleosynthesis prediction and meteorites are not consistent with the ones measured in old metal-poor stars and in current Solar atmosphere, respectively. These discrepancies are the long-standing "cosmological lithium problem" and "lithium problem in the Sun", which plague our current understanding of cosmology, stellar evolution, and Galactic chemical evolution. Here we propose to use ALMA to observe LiH (J=1-0) in the Milky Way toward two interestellar clouds. The determination of the interstellar Li abundance, along with the stellar Li distribution in our galaxy derived from the upcoming Gaia DR2 data, will allow us to understand the Galactic Li evolution and shed light on the lithium problems. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-10-31T11:07:16.000 |
| 4801 | 2022.1.00114.S | 5 | A robust black hole mass measurement for a z=6.326 QSO resolving the black hole sphere of influence | A great number of SMBHs in excess of 1e+9 Msun have been found at z>6, and explaining their formation mechanisms has become an enormous challenge. However, there is no direct confirmation that such massive SMBHs really exist in the early universe. We propose high resolution (0.04-0.07 arcsec) Band 6 observations for a luminous QSO at z=6.326, hosting the most massive central BH found to date, whose global kinematics is already constrained well based on previous [CII] observations. We will resolve the sphere of influence of the central BH with previously detected CO(17-16), most of which is likely to be emitted from the circum-nuclear disk. Our immediate objective is to measure the velocity curve based on the resolved CO(17-16) and to obtain a robust measurement of its central BH mass based on the position-velocity diagram (PVD). We will compare the PVD-based BH mass with the previous estimates from the empirical relation using the MgII line width and continuum luminosity (that will be updated with JWST using H-beta). If the BH mass obtained from this program is significantly smaller or even larger, it will have a great impact on our understanding of SMBH formation scenarios. | High-z Active Galactic Nuclei (AGN) | Active galaxies | 2024-07-06T00:46:16.000 |
| 4802 | 2018.1.01551.S | 13 | On the origin of [CII] in the Epoch of Reionization | One of the most controversial results on the study of distant (z>6.5) galaxies is the number of faint [CII] detections (including many non-detections) with ALMA. These findings indicate very diverse ISM conditions in primordial galaxies. Here, we propose to gain insight into the ISM state of the [CII]-emitting gas in a `normal' (SFR~20 Msol/yr) star-forming galaxy at z=6.8 with a bright [CII] detection, using Band 5 observations to measure [NII]205mum. We will derive constraints on the L_[CII]/L_[NII] luminosity ratio, which will reveal if the fine-structure line emission in this galaxy is HII or PDR dominated. We aim to provide insight into the so-called `[CII] deficit' in galaxies during the Reionization era by unveiling the ISM conditions that give rise to bright [CII] emission in this galaxy in the same epoch. | Lyman Break Galaxies (LBG) | Galaxy evolution | 2019-12-12T09:48:18.000 |
| 4803 | 2016.1.00041.S | 31 | Probing the earliest phases of massive star cluster formation in the Antennae system | Large populations of young massive star clusters are found in many nearby merging galaxies. We propose to observe the continuum emission from the overlap region of the Antennae (NGC 4038/39) to search for dense massive cores and young embedded star clusters that represent the earliest phases of massive star cluster formation. The Antennae merger contains one of the richest populations of young star clusters and is also close enough (22 Mpc) that the long baselines of ALMA can achieve 7~pc resolution, comparable to the sizes of optically-identified young star clusters in this system. Band 7 (350 GHz, 870 micron) continuum data will trace compact dusty cores masses greater than 10^6 Msun, while Band 3 (100 GHz, 3 mm) will detect free-free emission from young star clusters with masses greater than 2x10^5 Msun. Understanding how these young clusters form will provide important constraints on models of massive cluster formation that are also relevant to understanding the formation of globular clusters in the early universe. | Starbursts, star formation, Merging and interacting galaxies | Active galaxies | 2018-08-19T10:55:27.000 |
| 4804 | 2019.1.01812.V | 0 | Imaging the Shadow of Sgr A* with the Event Horizon Telescope | The EHT has recently published the first images of a black hole, using Cycle 4 observations of M87. These images reveal a prominent ring, consistent with the shadow of a black hole with 7 billion times the mass of the Sun. The angular size of the shadow of the Galactic Center supermassive black hole, Sgr A*, is precisely determined by stellar orbits to be 25% larger than that of M87. Detecting the shadow with EHT data will provide immediate tests of strong field gravity around a black hole. However, intrinsic variability makes imaging analysis of Sgr A* more challenging than M87. As the only EHT target with intra-hour variability and daily flares, Sgr A* is the most promising source to study the role of turbulence and magnetic fields on horizon scales. We propose for 31.5 hours observing Sgr A* with ALMA joining the EHT. These observations will include crucial new sites, Kitt Peak and NOEMA, significantly improving the capabilities for calibration, imaging, and time-domain studies. They can confirm persistent image features, such as the black hole "shadow", and will give the sharpest view ever obtained of the structure and dynamics near a black hole. | Galactic centres/nuclei | Active galaxies | 2024-10-25T18:49:57.000 |
| 4805 | 2018.1.00167.S | 1 | Measuring the elusive magnetic field strength in the disk of TW Hya | Magnetic fields likely play a key role in the evolution of protoplanetary/accretion disks. So far, the quest for determining the magnetic field strength in protoplanetary disks has remained unsuccessful. Now that ALMA offers circular polarisation, we propose to directly measure the magnetic field strength in the disk around TW Hya using Zeeman splitting of the CN radical. A number of models (e.g. Shu et al 2007) predict the vertical disk field strength (among others likely responsible for the observed disk winds), advected from the starforming cloud during the protostellar collapse, to be of order 10-30 mG in the region where the CN emission peaks. We show that we will be able to reach, using all CN(2-1) hyperfine transitions, a 5-sigma sensitivity to the magnetic field of 5 mG. The observations will guarantee the most accurate magnetic field measurement possible for a protoplanetary disk and directly confront the available theory on disk magnetic fields. | Disks around low-mass stars | Disks and planet formation | 2020-03-07T19:12:42.000 |
| 4806 | 2017.1.00503.S | 17 | Accreting ionized gas onto the Galactic Center Second Black Hole;IRS13E | We analyzed the DDT observation toward the Galactic Center with ALMA. The IRS 13E was identified as a strong compact object on the integrated intensity map of the H30a recombination line. The IRS 13E is a very intriguing IR object in the vicinity of Sgr A*. The line profile toward the IRS13E has a wing-like component with the velocity width of 650 km/s. The compactness is as small as 0.04" (from JVLA). The enclosed mass is estimated to be 1-2x10^4 Mo. The hypothesis that an IMBH is embedded in the IRS 13E has been proposed from that the massive stars in the object have the similar proper motion. Our detected ionized gas is presumably accreting onto the IMBH. The main scientific objective is the higher angular resolution spectral imaging of the accreting gas onto the IMBH in the H30a recombination line to reveal the kinematic structure of the ionized gas, which would prove the existence of the IMBH in the IRS 13E clearly. Moreover, the velocity field is necessary to derive the accretion rate onto the IMBH. The comparison with the X-ray luminosity would reveal properties of the accretion. | Galactic centres/nuclei | Active galaxies | 2019-01-26T20:41:32.000 |
| 4807 | 2022.1.01138.S | 16 | The Earliest Stages of Massive Binary Formation: Characterizing the 500 au protobinary in G11.92-0.61 MM2 | High-mass stars (>8 Msun) are distinguished by their very high multiplicity fraction, with >90% of main-sequence O and early B stars having at least one companion. In contrast to recent progress in observational studies of low-mass multiple formation, there remains a lack of observational evidence capturing the earlier stages of high-mass binary formation -- before the protostars are evolved enough to ionize their surroundings or excite hot core line emission. We propose high-resolution multi-wavelength imaging of the youngest known proto-high-mass binary system, recently discovered by ALMA in G11.92-0.61 MM2, formerly a candidate high-mass starless core. We will combine our proposed 0.04" (135 au) resolution Band 4 and Band 8 images with existing 0.04" Band 6 data to measure the luminosities of the protostars and the mass of their circumprotostellar material. With our proposed 0.02" (67 au) resolution Band 6 imaging, we will search for further multiplicity and resolve the morphology of the connecting structures for comparison with binary formation models. | High-mass star formation | ISM and star formation | 2024-07-01T03:19:31.000 |
| 4808 | 2019.1.01102.S | 53 | Identifying a SMG in the EoR | Until today, our understanding of the galaxy formation in the epoch of reionization (EoR) largely relies on rest-frame UV selected galaxies (Lyman alpha emitters, Lyman break galaxies, QSOs). This can lead highly biased view, and so uncovering IR regime at this epoch is of critical importance. Especially, the identification of submillimeter galaxies (SMGs) at the epoch is a key to unveil dusy, massive regime. Here we propose a line scan in ALMA band3 to identify spectroscopic redshift of a promissing candidate of a SMG in the EoR, which is selected from our careful analysis on the IRAC and submm/mm data. ALMA is a definitely only way to identify such a SMG. The successful identification will open a new window in understanding the galaxy formation in the very early universe. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2021-04-02T23:02:19.000 |
| 4809 | 2017.1.00489.S | 192 | How does CO trace the HI-to-H2 Transition at Low Metallicity? | A key remaining question in star formation and galaxy evolution is how the atomic gas transitions to molecular, and in particular, the effect of metallicity on this process. We propose to look for faint CO emission using the ACA in standalone mode towards a sample of sources spread across the Magellanic Clouds that have HI absortion observations as part of an ongoing large ATCA project lead by Co-I McClure-Griffiths. We will be able to compare the CO intensity to the HI spin temperature and fraction of cold neutral gas to constrain how metallicity affects the transition from molecular to atomic gas. By revealing how much CO emission exists along these lines of sight and comparing to the optical depth of HI determined from the absorption line measurements, we will constrain how much optically thick HI gas contributes to the "CO-dark" or "CO-faint" gas component at low metallicity. With the proposed ~80 single-pointings towards the background continuum sources with HI absorption measurements, we are in a unique position to study how environment affects the CO emission and its connection to the HI-to-H2 transition. | Inter-Stellar Medium (ISM)/Molecular clouds, Magellanic Clouds | ISM and star formation | 2019-12-18T18:02:10.000 |
| 4810 | 2016.1.01287.S | 18 | Confirming a massive proto-cluster of submm galaxies at z ~ 6 discovered by ALMA | While following up with ALMA a FIR-colour-selected sample of z > 4 SMGs, we have discovered an extreme cluster of SMGs at high redshift. Our previous 3--mm continuum data from ALMA show that the structure contains at least 6 submm sources within 30''. Four of the sources show emission at 98.4 GHz, which suggests that most (and possibly all) of the SMGs are actually at the same redshift, belonging to a unique, massive, star-bursting structure. The profile of the emission line in the brightest component is extremely broad (1040 km/s FWHM for a Gaussian fit, though the line profile is boxy). The most likely redshift, based on ALMA, JVLA, optical/ near-IR data and FIR SED is z = 6.0. Our best estimate of the total IR luminosity of the structure is an incredible LIR ~ 6E13 Lsun, or SFR ~ 10800 Msun/yr. This SFR is three times higher than that of the most intense dusty starburst found so far. Confirming that such an extreme star-bursting system has formed only a few hundreds of Myr after the Big Bang is of profound and urgent interest, since it poses a genuine problem for accepted models of galaxy and structure formation. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-08-07T19:37:26.000 |
| 4811 | 2017.1.00050.S | 34 | Spatial constraints on the cold dust in the shell around the AGB star V644 Sco | We propose to observe the shell around the carbon AGB star V644 Sco with the ACA in bands 6 and 7. In spatially unresolved observations with LABOCA on APEX towards V644 Sco, we detect a similar excess flux also detected in the shell around the AGB star R Scl. The submm observations towards R Scl are spatially resolved, and indicate that the excess flux originates from a cold dust component with large grains at 30 K, possibly revealing a large reservoir of dust mass from AGB stars. The lack of spatial constraints for V644 Sco severely limits the interpretation of the APEX data. The ACA observations will spatially resolve the shell around V644 Sco. They will effectively constrain the grain properties in the shell around this star by measuring the spectral index in the submm. The proposed observations offer a unique opportunity to study the contribution from AGB stars to the total galactic dust budget. If the large grains are confirmed also in V644 Sco, it would imply that our view on dust production in the Galaxy would have to be adjusted. | Asymptotic Giant Branch (AGB) stars, Evolved stars - Shaping/physical structure | Stars and stellar evolution | 2019-09-14T16:20:00.000 |
| 4812 | 2024.1.01518.S | 0 | A detailed view of spinning dust emission from NGC2023 | The anomalous microwave emission (AME) is a diffuse emission mechanism observed around 10-60GHz. It is thought to originate from dust grains rotating at GHz frequencies that emit trough electric dipole emission. AME has been detected from the reflection nebula NGC2023 at 22GHz using the VLA. The emission strongly correlates with a mid-IR map at 8um, highlighting the connection with small dust grains. Additionally, ALMA observations at 145 GHz constrain the contribution from thermal dust emission from the cloud. With the intention of characterizing the spectrum of AME, we propose to map NGC2023 using Band-1 continuum observations at 40GHz. This frequency is critical to disentangle spectral predictions from the spinning dust model. By combining these observations with the previous data sets, we will be able to characterize the spectrum of AME between 3 and 145 GHz. We also expect to detect morphological variation in the AME intensity between the 22GHz maps and the 39GHz data. Detecting these can inform us about changes in the environmental conditions of the cloud as well as variations in the grain size distribution. | Inter-Stellar Medium (ISM)/Molecular clouds, Photon-Dominated Regions (PDR)/X-Ray Dominated Regions (XDR) | ISM and star formation | 3000-01-01T00:00:00.000 |
| 4813 | 2017.1.01559.S | 112 | The Origin of z < 1 Damped Lyman-alpha Absorbers: Completing the Census | The population of Damped Lyman-alpha Absorption (DLA) systems seen towards background QSOs probe the bulk of the neutral hydrogen in the universe. Galaxies believed to be responsible for the absorption have been identified toward about two dozen DLAs at z < 1 through optical and IR imaging. The molecular content of some of these DLAs are currently being studied by ALMA through maps of spatially resolved CO emission, which will lead to important insights into the origin of DLA systems. However, a subset is currently being neglected: specifically, 3 DLA fields where no absorbing galaxy has been found, and 3 DLAs where the putative absorber is more than 20 kpc from the line of sight --- a distance not in keeping with the expectations for low luminosity galaxy disks --- do not yet feature in ALMA's programs. We propose observing CO(2-1) emission from precisely these systems. We aim to locate the absorbing structures in cases where no galaxies have yet been found, and where large galaxy disks are not expected. Complementing existing ALMA programs, our data will complete the census of z < 1 galaxies responsible for DLAs and avoid any bias in the interpretation of their origin. | Damped Lyman Alpha (DLA) systems | Cosmology | 2019-12-06T17:53:55.000 |
| 4814 | 2019.2.00031.S | 10 | Probing the Embedded Disk of the Giant Elliptical NGC 5128 (Centaurus A) | Many large elliptical galaxies contain embedded disks of dust and gas, remnants of a merger with a smaller gas-rich galaxy. The physical properties of such disks, and the resulting initial conditions for star formation are very different from those in disk galaxies and starburst galaxies. We will study these in detail by modelling the molecular gas in the embedded dusty gas disk ('dark band') of the only nearby giant elliptical, NGC 5128 (host of the radio source Centaurus A). We will apply PDR and radiative transfer models to the optically think 12CO and the optically thin 13CO and C18O J=1-0 and 2-1 transitions in maps of 20 pc resolution over the inner several kpc of the galaxy. From the maps we will deduce the mass and temperature, for individual clumps and as a function of radius, of the gas in the extended disk, and investigate the relation of the molecular gas conditions to the enhanced star formation in the disk. This is a continuation of 2013.1.00803.S (grade B). It is key that we recover all the flux, but unfortunately there is no sufficient ACA data for the 12CO(2-1) and 13CO(1-0) lines. Here we request the missing ACA observations to complete this project. | Early-type galaxies, Giant Molecular Clouds (GMC) properties | Galaxy evolution | 2021-04-16T21:29:10.000 |
| 4815 | 2021.1.01388.S | 6 | An Investigation of Latitudinal Variations in Titan's Atmospheric CH4 | As the progenitor of myriad trace organics that compose Titan's substantial atmosphere, placing constraints on the abundance and distribution of CH4 has been a fundamental driver for observations, photochemical, dynamical, and formation models of Titan. Previous measurements of Titan's CH4 abundance profile were made using the Huygens probe, and subsequently used throughout the Cassini era to derive Titan's stratospheric temperatures in the IR. Lellouch et al. (2014) observed variations in stratospheric CH4 between 1-1.5% as a function of latitude. However, further studies measuring spatial variations in CH4 have not been completed. Following the sub-mm detection of the CH3D on Titan (Thelen et al. 2019), we propose to observe CH3D in ALMA Band 9 with high spatial resolution and sensitivity. By simultaneously measuring temperature using CO and HCN we may infer CH4 abundances at ~10 distinct latitude regions across Titan and investigate spatial variability in Titan's mesopause for the first time. The confirmation of CH4 and temperature variations with latitude will prove crucial for dynamical and photochemical models, and further our understanding of Titan's complex atmosphere. | Solar system - Planetary atmospheres | Solar system | 2023-07-25T22:46:08.000 |
| 4816 | 2016.A.00026.S | 35 | Resolving disk-planet interaction in a nearby Transition Disk | Transition Disks are thought to be prime candidates of disks hosting young planets, mostly based on indirect evidence. Planets have been found by direct imaging in a few cases. Finding planets and studying disk-planet interaction is critical to understand planet formation and disk dispersal. By means of high contrast infrared imaging, we detected direct evidence for a planetary mass companion inside the cavity of a nearby transition disk and of its interaction with the disks. The available ALMA observations show some tantalizing evidence for disk disturbance, but do not have sufficient angular resolution to really resolve the structures. We require a modest amount of time to resolve the disk-planet interaction signarure in the dust and gas. | Disks around low-mass stars | Disks and planet formation | 2018-02-28T12:55:34.000 |
| 4817 | 2021.1.00286.S | 42 | Do magnetic fields diversify gas fragmentation at sub-0.1 pc scales in the Central Molecular Zone? | Magnetic fields have been suggested to be dynamically important in the fragmentation of dense gas in high-mass star formation regions in the Galactic disk. The Central Molecular Zone (CMZ) around the Galactic Center represents a different star forming environment than the Galactic disk, where the role of magnetic fields in gas fragmentation is undetermined. Previous research of the CMZ reveals five massive clumps with similar densities, turbulence strengths, and evolutionary phases, but vastly different fragmentation at sub-0.1 pc scales. The last unexplored component that may be able to regulate fragmentation is magnetic fields. Therefore, we propose to observe polarized dust emission at 0.01 pc resolution to determine whether magnetic fields are responsible for the different fragmentation and thus star formation states in the five clumps. We will also compare with Galactic disk samples to investigate how magnetic fields impact gas dynamics in the unique environment of the CMZ. This will be the first high angular resolution (<1") polarization observation toward the CMZ and represents a 50-100 times improvement in resolution compared with existing single-dish polarimeter data. | High-mass star formation, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2023-09-26T15:51:27.000 |
| 4818 | 2019.1.00768.S | 51 | Tracking the lifetime and resolving the properties of the massive protostellar accretion outburst in G358.93-0.03 | The recent identification of accretion outbursts in two massive protostars, both heralded by 6.7 GHz methanol maser flares, has invigorated single-dish maser monitoring programs on a quest to find more cases. As a result, a third event was discovered on 14-Jan-2019 in a poorly-studied massive star-forming region G358.93-0.03. Since then, the global maser community has discovered 20 new torsionally-excited methanol maser transitions from 6 to 360 GHz toward this source(!), all likely powered by an ongoing accretion outburst in a massive protostar. SMA and ALMA DDT observations have pinpointed the deeply-embedded outbursting object, which powers a line-rich hot core and lacks a near-IR counterpart, much like NGC6334I-MM1. Measuring the lifetime of the excited masers and the rate of decline of the heated dust continuum is now critical to compare to the first two cases, which we will achieve by repeating the 400 au resolution DDT observations in Band 5 and 7. We also propose new Band 6 and 7 observations designed to disentangle the multiple outflows present in the host protocluster, and assess the energetics, and hence dynamical impact of massive protostellar episodic accretion. | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2022-07-12T00:00:00.000 |
| 4819 | 2019.2.00172.S | 51 | The Large scale structure of the recurrent nov T pyx | T Pyx is unique amongst recurrent novae in being surrounded by a nebula formed of material ejected during previous eruptions. The latest one occurred in April 2011 and was observed in all wavelengths from X-rays to radio. Since then, the ejected material has expanded to form the most inner ring in T Pyx' complicated shell structure. With ACA 7-m array, we will be able to see this whole shell structure, and constrain fluxes from large spatial scales. This will allow us to compare the flux we derive now to previous single-dish measurements done after the nova eruption in 2011. This allows to distinguish whether that continuum flux originated mainly in synchrotron or dust emission. The proposed observations will yield the most up-to-date measurements of the continuum flux over the extended structure. The main purpose of these observations is to provide the necessary information for a future ALMA proposal to study the structure and kinematics of the new inner shell resulting from the latest eruption. | Cataclysmic stars, Supernovae (SN) ejecta | Stars and stellar evolution | 2021-04-07T15:24:26.000 |
| 4820 | 2012.1.00628.T | 0 | Molecular Absorption Survey against the G2 Cloud Sgr A* Accretion Event | Recently, a cloud, G2, hs been detected on an orbit that will eventually accrete on Sgr A*. Predictins are that the continuum flux will drastically increase during the event. We apply for ALMA TOO time that is triggered when the source will be brighter than 6Jy. This is bright enough to observe molecules in absorption against Sgr A* down to 10^-3 in opacity. In Cycle 0, we were successful to obtain a molecular absorption survey against the supermassive black hole in Centaurus A. Covering a very similar molecular lines, we will be able to directly probe the environments of our own Milky Way from the nearby gas, through the majority of the disk includign three spiral arms, to the Central Molecular Zone and the 4pc central nuclear disk, into the immediate Sgr A* environment. This event is a unique opportunity to probe the molecular environment of the Milky Way. We will also apply for VLA time to perform the cm counterpart of the ALMA mm line survey. | Astrochemistry, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2016-10-29T08:12:54.000 |
| 4821 | 2017.1.00845.S | 32 | Tracing the Carbon Chemistry Associated with Planet Formation | ALMA observations have revealed that gas-rich protoplanetary disks have an active chemistry that may influence the chemical composition of the gas and in pre-planetesimal solids. One central indication of this active chemistry is the production of striking rings seen in the emission of simple hydrocarbons (C2H and C3H2) in two nearby solar analog disk systems. Chemical models suggest two potential sources to power hydrocarbon formation: extraction of carbon from CO or photoablation of PAHs. We propose to use ALMA to perform a simple experiment. We will observe C2H and C3H2 towards 6 Herbig Ae/Be systems which have a wide range of PAH emission that spans nearly two orders of magnitude in PAH luminosity and estimated PAH mass. In some instances, the distribution of the UV illuminated PAHs is known on scales comparable to our proposed resolution. With these observations we will provide a definitive test of the origin of hydrocarbons in disk systems. If small hydrocarbons form via PAH photodestruction then we should find a correlation between C2H/C3H2 emission with overall PAH emission with comparable emission distributions. | Disks around low-mass stars, Disks around high-mass stars | Disks and planet formation | 2019-10-15T22:18:22.000 |
| 4822 | 2017.1.01367.S | 18 | Disentangling the fibers of L1495/B213 | Filamentary structures dominate the large-scale images of clouds made with Spitzer and Herschel, and suggest that star formation is associated to the process of filamentary fragmentation. Spitzer and Herschel images, however, only trace the distribution of dust, and therefore lack information on the gas velocity field. When this information is added, using molecular line observations, many filaments are found to be in fact complex networks of smaller structures often called fibers. These fibers seem to be the true parent structures of the dense cores and protostars, and therefore the ultimate place of star formation. In this proposal we request ALMA time to observe the most nearby group of fibers, located in the L1495/B213 region of Taurus. Our C18O(1--0) observations will aim to disentangle a surprisingly complex network of fibers that seem to be at a very early evolutionary state. With these observations we aim to characterize the internal properties of the fibers, and to shed some light on their not-yet-understood process of formation. | Low-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2020-08-17T13:24:16.000 |
| 4823 | 2019.1.00711.S | 18 | Detection of a molecular gas disc around M31 nuclear black hole | Andromeda is a green valley galaxy, with an inside-out quenching of its star formation activity. It hosts the closest supermassive black hole, known to be quiet with some murmurs at 10^-10 LEdd (Li et al 2011), and to be surrounded by an eccentric disc of old stars (Tremaine 1995). The gas expulsed by mass loss of red giants and asymptotic giant branch stars is expected to accumulate within the tidal truncation radius of 1 pc (=0.26). Chang et al (2007) predicted the presence of a 10^4 Msol molecular gas disc, corresponding to a CO signal of 2 mJy with a linewidth of 1000 km/s. We observe Andromeda nucleus with NOEMA at IRAM/PdB in CO(1-0), and exclude this scenario at 9 sigmas, with a 3.37x2.44 beam (Melchior & Combes, 2017). The 1-pc signal has been diluted by a factor of about 100 due to the angular resolution. We propose to observe CO(3-2) with ALMA M31s nucleus with an angular resolution of 0.12, a spectral resolution of 1.7 km/s and a rms sensitivity of 0.2 mJy for a bandwidth of 260 km/s. We would thus gain a factor of about 10 in sensitivity with respect to our previous NOEMA observations. This impressive gain motivates our proposal for this target with a low elevation. | Spiral galaxies | Local Universe | 2022-07-19T12:08:21.000 |
| 4824 | 2023.1.00958.T | 0 | Monitoring Post-Flare Protoplanetary Chemistry with ALMA | High energy radiation from young pre-main sequence stars is one of the main drivers of the physical and chemical evolution of planet-forming disks. Traditionally, stellar radiation is assumed to be relatively constant over the course of millions of years, but in reality, young stars are incredibly dynamic. For example, X-ray flares can increase the ionization within the circumstellar disk by several orders of magnitude. Flares may play an important role in determining the long-term composition of planet-forming regions, but the direct effect of an X-ray flare influencing chemistry in real time has not yet been detected. This proposal aims to do just that. This Target of Opportunity will be triggered by Chandra observations of the Orion Molecular Cloud, where we will measure flare driven enhancement and decay of HCO+ isotopologues in four protoplanetary disks. Disks will be selected based on flare strength, known millimeter emission, and visual extinction. This set of observations will directly measure electron recombination timescales, and therefore the ionization and electron abundances, in a protoplanetary disk. | Disks around low-mass stars | Disks and planet formation | 2025-02-21T22:27:10.000 |
| 4825 | 2011.0.00367.S | 0 | Outflow Entrainment in HH 46/47 v0.6 | We propose to study the molecular outflow from the HH46/47 flow. This spectacular outflow shows one of the best-defined cavities in the infrared and has been studied extensively in the optical and IR. However, a high-resolution map of the entire molecular (CO) outflow is still missing –essential for obtaining a complete picture of the outflow phenomenon and its impact on the cloud. The proposed mosaic will allow us to map the entire extent of the flow, using the CO(1-0) line at a ~4.5” resolution. With the data, we will study the morphology, velocity and momentum distribution of the entrained gas. Simultaneous observations of SO2 and SO lines will probe shocks along the outflow axis indicative of episodic ejection events. We will use the ALMA data, as well as the known properties of the protostellar wind from existing optical and IR data, to model the outflow using a 3D hydro-dynamical code. This will allow us to study the outflow entrainment mechanism and wind collimation properties, and will place constrains on the wind-launching mechanism. In addition, we will test whether the asymmetry in the molecular outflow seen in single dish CO observations is in fact due to the lack of molecular gas northeast of the source or is just due to a lack of sensitivity in the single-dish observations. Simultaneous observations of C17O(1-0) will probe the impact of the outflow on the surrounding dense core gas. This study will help increase our knowledge of the outflow entrainment mechanism and the outflow impact on the surrounding dense core of a Class I YSOs –the first steps needed to fully understand the role of outflows in the core dispersal process. | Outflows, jets and ionized winds, Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2013-03-30T14:51:00.000 |
| 4826 | 2019.1.01537.S | 110 | A joint ALMA-KMOS program to probe the ISM physics and galaxy evolution at z~2 | Probing the molecular phase of the ISM at the epoch of the peak of mass assembly (1 | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2021-04-06T04:14:45.000 |
| 4827 | 2021.1.00588.S | 20 | Putting Star Formation Feedback Theories to the Test | In this proposal we seek deep CO(2-1) observations of 5 star bursting disk galaxies that are part of the DUVET survey. We will measure gas mass and outflow kinematics in 1 kpc resolution maps. We will combine this with Keck/KCWI data from the DUVET survey to test theories of feedback. Feedback regulated star formation theory is a widely popular theory to describe the self regulation of gas in galaxies. Recent observations show that this fundamental theory may be failing to describe high SFR surface density disk galaxies by multiple orders of magnitude. Because roughly 2/3 of star formation happens at high-z in high SFR surface density galaxies, the current failure implies this widely adopted theory may not be able to describe most star formation in the Universe. Our observations are designed to (1) test this theory on kiloparsec scales (previous tests were galaxy averages) and (2) study the kinematics of the outflows and their possible relationship to this failure. If assumptions about the launching mechanisms that drives the feedback are found to be incorrect, and to couple to this failure this could explain the descrepancy and motivate future theories. | Outflows, jets, feedback | Active galaxies | 2023-12-21T20:33:40.000 |
| 4828 | 2019.1.01757.S | 54 | The importance of the AGN-driven molecular outflows in a representative sample of nearby ULIRGs | AGN-driven outflows are now considered a key element in the evolution of galaxies. However, although much of the mass of such outflows appears to be tied up in the molecular gas phase, considerable uncertainties remain about how the molecular outflows relate to those detected in other gas phases, and whether they are truly powerful enough to affect the evolution of their host galaxies. Therefore, we propose high-resolution ALMA CO(1-0) observations to make a systematic study of the molecular outflows in a representative sample of 7 nearby ULIRGs (z < 0.14) for which we already have obtained precise measurements of the radii, masses and kinetic powers of their warm, emission-line outflows. The observatios will be crucial for establishing the acceleration mechanism for the molecular outflows, their relationship to warm outflows detected in the same objects, and their true reach and energetic significance. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2022-09-03T00:00:00.000 |
| 4829 | 2016.1.00978.S | 19 | Observing Exceptionally Bright Galaxies at z~6.6 in [CII] and Dust Continuum | We found 2 exceptionally bright Lya emitter (LAE) candidates at reionization epoch z~6.6, VIKING-z66LAB and VIKING-z66LAE-1, in our wide-field narrowband survey. They have remarkable Lya luminosities 3.4-3.9 x 10^43 erg/s and rest-frame Lya equivalent widths EW ~ 163A and >755A; these are comparable to or even greater than the brightest z~6.6 LAEs known such as Himiko and CR7. VIKING-z66LAB is also an extended Lya blob with >~3" (15 kpc) size in Lya emission, comparable to sizes of Himiko and CR7. Himiko and CR7 are known as triple merger systems, and CR7 exhibits strong HeII 1640A emission, no metal lines and a PopIII-like stellar population. Thus VIKING-z66LAB may also be a rare multiple merger system with PopIII stars. VIKING-z66LAE-1 (1.8" size in Lya) may also be a single galaxy (or closely interacting ones) with PopIII due to its extremely high Lya EW. We propose to observe them in [CII] and dust continuum to measure the enrichment of the ISM. If [CII]/dust is detected, they are not PopIII hosts but still extreme LAEs. We will compare their kinematics, dynamics, ISM, dust properties to those of normal galaxies and constrain z~6.6 reionization state from their [CII] and Lya. | Lyman Alpha Emitters/Blobs (LAE/LAB) | Galaxy evolution | 2019-07-13T22:30:16.000 |
| 4830 | 2017.1.00786.S | 50 | Apocenter glow in the Gyr-old debris disk of HR 1010 | There are few observations of old debris disks similar in age to our Solar System, and opportunities to observe mature typical systems containing eccentric planets are rare. Therefore, we propose to use ALMA in Bands 6 and 7 to observe the sub-mm excess from the Gyr old debris disk of the sun-like star HR 1010. Herschel observations reveal a double lobe brightness asymmetry (pericenter-glow), which indicates this debris disk is significantly eccentric (e>0.3), most likely shaped by an undetected eccentric planet. At ALMA's Band 6 and 7 wavelengths, this brightness asymmetry is expected to be reversed (apocenter-glow), but more importantly, to vary from one Band to another, depending on the disk's dust properties. Together with Herschel data, ALMA data will help characterize the variations of the brightness asymmetry with wavelengths, while providing constraints on the disk geometry. It will allow us to build a comprehensive model of the ring dust population, teaching us about the planetary systems formation and evolution processes at the origin of the most eccentric belt shaping perturber ever inferred at large distance from a solar-type star, and to better characterize it. | Debris disks, Exo-planets | Disks and planet formation | 2018-12-02T14:50:35.000 |
| 4831 | 2011.0.00820.S | 0 | A 170 GHz-wide Complete Spectral Scan of an IR-pumped, Luminous Infrared Galaxy | A wide-band, high-quality, unbiased census of mm/submm lines has now become possible with the advent of ALMA. Here, we propose an ALMA cycle 0, 170 GHz-wide complete spectral scan of the luminous infrared Galaxy NGC4418. For a compact galaxy nucleus such as the one in NGC4418, the line confusion limit can be achieved within a short integration time in cycle 0. NGC4418 is a benchmark object for LIRGs and one of the best targets known to demonstrate the capabilities of ALMA cycle 0. A rich scientific return is guaranteed and will help to understand the molecular emissions from dusty galaxies through cosmic time. With the proposed spectral scan we can identify and quantify excitation mechanisms (collisional, radiative, new maser lines), determine abundances, find new absorption and emission lines, and compare to other Galactic and extragalactic objects. Gas motions through line wings, P-Cygni profiles, or line emission channel maps can be probed in great detail. The narrow (170 km/s) spectral lines allow for a revealing picture of the nuclear chemistry and excitation of NGC 4418 since lines and species can be separated. The first extragalactic submm vibrational lines of HCN and HC3N were detected in NGC4418 and this shows great promise for a rich IR-pumped spectrum and a large variation of species, a research area that warrants further exploration if we are to understand the most dust-enshrouded phases of galaxy evolution. | Luminous and Ultra-Luminous Infra-Red Galaxies (LIRG & ULIRG), Galaxy chemistry | Galaxy evolution | 2014-01-18T12:52:22.000 |
| 4832 | 2016.1.00648.S | 36 | How is Gas Organized in a Tidal Dwarf Galaxy? | Tidal dwarf galaxies (TDG) form in the debris of galaxy mergers, have higher metallicity than typical dwarfs (inherited from their parent galaxies), and are largely devoid of dark matter. Despite their interest as an extreme dynamical environment, no study so far has resolved molecular gas in TDGs down to giant molecular clouds (GMC), the scales at which star formation takes place. Our target TDG has uniform gas surface density, but star formation is restricted to a thin ridge in the south. We propose CO(2-1) observations at 0.8" (60pc) to: 1) resolve for the first time GMCs in a TDG and determine what fraction of the gas is in bound structures; 2) test if GMC properties vary and if this can explain the stark north-south differences in star formation activity; 3) determine the typical progenitor GMCs of the HST-identified young stellar clusters to fully constrain the star formation history of the system; 4) directly assess the impact of internal cloud turbulence and local dynamics in the process of star formation. This pioneering study will characterize the gas organization in a newly-formed TDG, and lay the foundation for testing star formation theories across cosmic environment. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2018-02-23T14:50:52.000 |
| 4833 | 2015.1.00420.S | 39 | Can the passage of a radio jet compress the molecular gas in a galaxy? | Gas compression is a requirement for jet-induced star formation. We aim to test whether the passage of a radio jet leads to the compression of the molecular gas it encounters in an ideal target: the nearby elliptical IC5063, in which a jet propagates through a disk. Using ultra-deep SINFONI observations, we demonstrated that the jet unambiguously accelerates atomic & molecular gas along and perpendicularly to its trail. The gas velocities exceed ordered motions by 600-1200 km/s near four different bending points of the jet. The entrained/scattered gas extends far, sweeping the galaxy's inner square kpc. Having a map of the outflowing molecular gas at high temperatures from SINFONI, we now aim to create a map of the outflowing molecular gas at high densities from ALMA, in order to identify regions of high pressure. In these regions, we will investigate whether the ISM is more or less prone to star formation. We request CO(1-0),(3-2), and (4-3) observations to run CO excitation models and obtain a density map. To directly probe the high-density regime and constrain the models, we request HCN, HNC, HCO+(1-0) and HCO+(4-3) observations. | Outflows, jets, feedback | Active galaxies | 2017-07-14T11:59:39.000 |
| 4834 | 2015.1.00496.S | 1 | High-mass disk formation and fragmentation | Understanding the fragmentation and rotation properties of disks around young high-mass stars remains one of the key questions in star formation research. The unique capabilities of ALMA allow us to probe the physical properties of the gas and dust in the inner envelope and disk region around the central high-mass star. Specifically, using the long baselines in the 1.3mm band result in a spatial resolution of ~0.05'', allowing us for the first time to resolve the predicted fragmentation scales on the order of ~100AU. Therefore, we propose to observe one of the best 10^5 Lsun high-mass disk/outflow candidates G351.77-0.54 at 230GHz in continuum and spectral line emission. Important questions which these observations will address are: What are the fragmentation properties of this massive disk candidate? Are the kinematic properties of the disk-like structure of Keplerian nature dominated by the central object or still strongly influenced by a flattened envelope? Are outflow properties, e.g., possible outflow rotation, directly linked to those of the accretion disk? | Outflows, jets and ionized winds, High-mass star formation | ISM and star formation | 2017-05-07T01:35:18.000 |
| 4835 | 2017.1.00180.S | 438 | Define the physic of high-mass star formation from the cold Hershel sources of the NGC6334 complex | Despite all the recent efforts to characterize the earliest phases of high-mass star formation, the existence of high-mass pre-stellar cores is still debated. NGC 6334 is the closest most massive molecular complex of the Southern hemisphere forming high-mass stars. The Herschel/HOBYS program made a survey of NGC 6334 and an utter search for cloud fragments able to form high-mass stars. HOBYS revealed 29 cold, massive dense cores (MDCs) hosting either young high-mass protostars, massive pre-stellar cores, or both. We here propose to: -follow the fragmentation of these ~0.1 pc Herschel sources down to the ~2000 AU scale of protostars -seek CO outflows to distinguish between high-mass protostars and massive pre-stellar cores -compare the fragmentation level of protostellar and starless MDCs -measure the turbulence level of high-mass protostars and massive pre-stellar cores using 13CS and N2D+ lines, respectively -look for gas stream flowing from parsec-scale to 2000 AU protostars in DCO+ and DNC -conclude on the most likely scenario to form high-mass stars: either the local collapse of a turbulent massive pre-stellar core or the clump-scale gas accretion onto a low-mass protostar. | High-mass star formation, Astrochemistry | ISM and star formation | 2020-07-17T20:55:10.000 |
| 4836 | 2011.0.00476.S | 0 | Directly Probing Physical Processes in a H-ATLAS Selected lensed bright IR Galaxy at z~1 | The largest extragalactic Herschel survey, H-ATLAS, has provided by far the brightest sample of lensed FIR galaxies. CO-ladder redshifts from Z-Spec are available for a subset of the sources, but the lines have typically not been spatially or spectrally resolved. With ALMA we are thus positioned to study in detail the galaxies that dominate the FIR background and the star-formation-rate density at the peak epoch of starburst/AGN activity. Here we propose observations of the CO ladder (J:2-1, 4-3, 11-10, 12-11), [CI], 13CO and C18O, CS, and H2O of the z=1.027 H-ATLAS source G15v2.19. Our immediate science goals are to (a) map the morphology and kinematics of the cold gas on sub-kpc (almost GMC) scales and thus determine the lensing model, galaxy size and morphology (merger? rotational or dispersion support?), and GMC or GMC-cluster masses, sizes and luminosities; (b) determine physical properties of PDRs and XDRs from the CO and (limited) CS and H2O ladders and dust temperature; (c) determine gas and galaxy masses, and the star formation rates and lifetimes; (d) select the optimal strategy to observe H-ATLAS samples in Cycle 1 and beyond. This Chilean-led project, together with complementary H-ATLAS-team proposals, will build a fast-track statistically meaningful sample of high-z lensed IR galaxies over the first few ALMA cycles. | Starburst galaxies, Gravitational lenses | Active galaxies | 2013-08-02T20:34:00.000 |
| 4837 | 2017.1.00467.S | 36 | [C I] imaging of a gaseous debris disk: 49 Ceti | We propose the observation of the fine-structure line of atomic carbon ([C I]3P1-3P0; 492GHz) in Band 8 toward a gaseous debris disk around A-type star, 49 Ceti at an angular resolution of 0.4". Our aim is to reveal the spatial and velocity structure of the [C I] emission from the CO gas disk. We have recently detected the [C I] line toward 49 Ceti with the ASTE 10 m telescope, and have found that its line shape resembles that of CO (Higuchi et al. 2017). This result suggests that atomic carbon (C) coexists with CO in the debris disks, and is likely formed by the photodissociation of CO. Moreover, the C/CO ratio is derived to be as high as 54±19. The high C/O ratio implies a small amount of H2. The gas to dust ratio is thus estimated to be ~4. With ALMA, we observe the distribution of the [C I] emission, and explore the variation of the gas to dust ratio (H2/dust) in the debris disk in combination with the CO and dust continuum data. The result will provide us with novel information on gas dissipation in the planetary-system formation. | Debris disks | Disks and planet formation | 2019-09-28T20:51:05.000 |
| 4838 | 2017.1.01398.S | 38 | Star formation inside galactic outflows: properties of the associated molecular gas and star formation efficiency | While galactic outflows are generally invoked to suppress star formation, some recent models have proposed that the outflowing molecular gas can undergo star formation. This new star formation mode would have fascinating important implications, since the stars formed in the outflow would have high radial velocities, hence this mode may contribute to the morphological and dynamical evolution of galaxies. We have recently discovered evidence for star formation occurring in the outflow of a nearby galaxy. Stars are forming at a rate of about 15-30 Msun/yr and with radial velocities of a few hundred km/s. We propose to characterize the properties of the molecular gas in this star forming outflow with a first exploratory programme aimed at observing CO(1-0) and a few tracers of the dense molecular gas. The goals of the observations are: 1) obtain a first assessment of the content of molecular gas and of its distribution in the outflow, hence providing the star formation efficiency of this new mode of star formation; 2) characterize the properties of the outflowing molecular gas, hence shedding light on the conditions that enable star formation in this unusual environment. | Outflows, jets, feedback | Active galaxies | 2019-03-27T17:21:05.000 |
| 4839 | 2021.2.00119.S | 11 | Understanding the origin of core masses in filaments: A deep census of dense cores in the NGC6334 filament | ALMA (Cycle3) observations of the NGC6334 filament at 3mm have revealed 26 compact, intermediate-mass dense cores (~0.03 pc, ~10 Msun, on average), as well as 2-5 velocity-coherent fiber-like substructures detected in N2H+. Overall, the massive NGC6334 filament (~1000 Msun/pc) has a density/velocity structure which is remarkably similar to that of the low-mass Taurus filament (~50 Msun/pc), despite being an order of magnitude denser. The main difference is that the dense cores in the NGC6334 filament appear to be an order of magnitude more massive than the Taurus cores. This result suggests that denser filaments form more massive cores and sets new constraints on the origin of stellar masses in different mass regimes. We propose 0.85mm observations of the NGC6334 filament in order to probe deeper (by 1-2 orders of magnitude) into the core mass function (CMF) of the filament and firmly establish that it is shifted to higher masses compared to the typical CMF observed in nearby, low-mass star-forming clouds such as Taurus. While other projects address the CMF/IMF of protoclusters/hubs, this project is unique in targeting the CMF produced by a single, well-documented dense filament. | Intermediate-mass star formation, Pre-stellar cores, Infra-Red Dark Clouds (IRDC) | ISM and star formation | 2023-12-29T14:41:45.000 |
| 4840 | 2022.A.00037.S | 18 | HLTau Band 1 continuum: observatory project | Observatory project to observe HL Tau in continuum in band 1. only a limited number of antennas available, and configuretion/required resolution is not consistent, so probably will need to be run from the OMC. SB just needs to be repeated in config 8 or 9, to | Disks around low-mass stars | Disks and planet formation | 2024-04-09T16:51:54.000 |
| 4841 | 2019.1.00603.S | 11 | A galaxy on fire: witnessing the initial phase of starburst in the core of a distant cluster? | Being unparalleled in terms of imaging quality and depth compared to competing projects, the Subaru Hyper Suprime-Cam (HSC) survey is the only existing large-scale extragalactic survey capable of delivering large galaxy cluster samples out to z=1.4. Through a systematic visual inspection campaign of the HSC cluster sample at z>1, we have fortuitously discovered a blue ring encircling a red galaxy, located at the center of a low mass cluster. Using archival and our own optical spectroscopic data, we have established that both the ring, its central galaxy, and two neighboring galaxies are all at the same redshift, z=1.06. Furthermore, the galaxy trio is strongly detected in archival Spitzer and Herschel data, indicating a star formation rate of 200 Msun/yr. It appears that the cluster center is experiencing an intense episode of star formation. We propose to conduct CO(2-1) transition observation of the cluster, to (1) measure the gas kinematics of the ring system, and (2) measure the total molecular gas content in the cluster center. The data will allow us to uncover the origin of the star forming ring, and the star formation activity in the core of this cluster. | Starburst galaxies, Galaxy Clusters | Active galaxies | 2021-06-26T10:02:55.000 |
| 4842 | 2016.1.01197.S | 17 | Zooming in to the Disk around the Massive Protostar W33A | We propose to follow-up our cycle 1 observations to fully trace the 3D velocity field of the material accreting onto a newly forming O-star at 100 au scales. Our target, W33A, is nearby (2.4 kpc) and is a well studied massive young stellar object already having a rare combination of high resolution observations at near-IR (Gemini-LGS-AO - 0.13") and mid-IR (VLTI-MIDI - 0.04") in addition to our cycle 1 ALMA data at 0.2" resolution. The latter show some signs of a rotational structure perpendicular to the well defined bipolar outflow, suggestive of formation via a disk for this O-star. However, any large scale disk appears disrupted by either infalling streams, fragmentation due to gravitational instability, or interaction with companions. Our well developed 3D radiative transfer models (dust & gas) including infall from the outer rotating envelope onto a compact Keplerian disk predict that ALMA will reveal the disk structure on the longest baselines on scales inaccessible to any other instrument at these wavelength and test massive star formation theories. | Disks around high-mass stars | Disks and planet formation | 2018-09-09T01:48:37.000 |
| 4843 | 2018.1.01575.S | 72 | Optimized Search for Quasar Absorber Counter Parts | The diffuse gas in the outer halos of galaxies can be efficiently probed by quasar absorption lines that offer a powerful tool to study the gas accretion onto the galaxies and the exchange of the gas with their surroundings. Identifying the galaxy counter part of these absorbing systems has proven to be difficult. Here we propose a new selection technique based on strong H2 absorption measured in the UV. The presence of H2 in absorption indicates the existence of a large reservoir of molecular gas which makes them very obvious targets for CO emission line observations. We have compiled a sample of molecular gas-rich absorbers at z<1.5 for which we aim to observe the lowest CO line transitions available in Band 3 and 4. We will identify the galaxy counterpart, measure molecular gas masses, relate the molecular gas in emission and absorption and evaluate the success rate of this promising new approach. | Damped Lyman Alpha (DLA) systems, Galaxy structure & evolution | Cosmology | 2019-11-07T11:20:32.000 |
| 4844 | 2023.1.00340.S | 0 | The Infrared Dark Cloud G034.77-00.55 and the first fully resolved interstellar magnetised shock | Magnetohydrodynamic (MHD) shocks are violent events that dramatically modify the physical and chemical properties of the Interstellar medium. Their existence has been indirectly reported toward several astrophysical environments, but their typical internal structure remains unresolved. Indeed, most shocks develop over spatial scales that are too small to be measured with current instrumentation. However, ALMA has recently shown, for the first time, the internal structure of the large-scale MHD shock driven by the SNR W44 into the molecular cloud G34.77-00.55. The data publicly available are however not sufficient to constrain the physical properties of the shocked gas and the shock structure. Hence, we propose to observe multiple CO transitions toward this shock to measure the kinematic temperature and density of the gas and to spatially resolve how these quantities vary across the shock front. We also request high-angular resolution SiO images to detect the shock magnetic precursor. The new observations complement existing archival data and will provide an unprecedented direct test to our current understanding of MHD shock theories. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2025-08-12T17:13:37.000 |
| 4845 | 2018.1.01695.S | 38 | Extragalactic Cloud Scale Observations of High Critical Density Tracers - Bridging the Gap to the Milky Way | Low resolution mapping of high critical density tracers like (e.g., HCN, HCO+, HNC, CS) and wide-field, high resolution CO mapping across nearby galaxies have each tremendously improved our understanding of the physics regulating star formation in galaxies. Here, we propose to take the next major step by combining both approaches: cloud-scale (high resolution) mapping of density-sensitive lines over a wide field in the nearby, massive, vigorously star forming spiral galaxy NGC 2903. ALMA is uniquely suited due the combination of sensitivity and resolution required for this innovative program. Our main goal is to relate gas density, star formation and molecular cloud properties across almost the entire galaxy disk (nuclear burst, gas-rich bar, spiral arms) for the first time at molecular cloud scale. This is possible also due to a unique ancillary data set at matched scales, including 12CO(2-1) arc-second mapping from our ALMA large program PHANGS. This program will put popular star formation theories to the test in diverse environments, link directly to studies of local Milky Way clouds and test how well common extragalactic "dense gas tracers" tell a self-consistent story. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2020-10-29T15:41:32.000 |
| 4846 | 2016.1.00079.S | 34 | Wind properties of the very-metal-poor Halo giant star RU Vul | This very short proposal aims to measure, and likely resolve, the CO (2-1) and (3-2) emission from the oxygen-rich Halo giant RU Vul. At 1/20th of solar metallicity, this is by far the most metal-poor star to have these observations done. The line width will tell us what the driving mechanism of the stellar wind is. The line strengths will inform us of the mass-loss rate, likely further constrained by the measurement of the CO envelope diameter. We also hope to probe inhomogeneities in the outflow. The results of this pilot study will be used to inform future observations, which will help determine the physics of mass loss from metal-poor stars, and calibrate mass-loss rate measurements in existing observations. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2018-03-28T18:17:14.000 |
| 4847 | 2017.A.00046.T | 45 | Radio Polarlimetry of AT2018cow/ATLAS18qqn | High-cadence optical time-domain surveys have been revolutionizing our knowledge of the transient universe over the past several years. One of them is a population of fast-rising, luminous events associating with the SNIc with non-thermal radiation, suggesting an engine-powered explosion linked closely with GRBs. Therefore, ongoing research aimed at understanding progenitor stars represents one of the most pressing inquiries in modern astrophysics. Undoubtedly one of the most critical measurements is the Faraday depolarization along with spectrum evolution caused by non-energized electron, which requires the revision of the standard mass of the progenitor star. As we demonstrated by making the first radio polarization measurement with our Cycle 5 program, linear polarizations in Band3 with the high sensitivity are essential for discovering these non-energized electrons, because the Faraday depolarization caused by the non-energized electrons suppress the linear polarization degree at a frequency of 100-1000 GHz. To extend this scientific field, we aim to apply the same method for the recently discovered AT2018cow/ATLAS18qqn that already exhibited large non-thermal component. | Gamma Ray Bursts (GRB) | Cosmology | 2018-12-29T13:36:39.000 |
| 4848 | 2022.1.01556.S | 150 | WALLABY-CO survey of the Hydra cluster: a better understanding of environmental effects on cluster galaxies | Environmental processes play a key role in changing physical properties of cluster galaxy populations. The degree of environmental effects on galaxies could be different in various clusters, depending on the physical properties of clusters (dynamical states, masses). Consequently, it is expected that the properties of molecular gas and star formation history vary from cluster to cluster. Thus, several systematic CO observations for nearby clusters are required to study the environmental dependency of the molecular gas and star formation properties. Using the Atacama Compact Array (ACA), we propose to obtain 12CO (2-1) images of 15 WALLABY galaxies in the Hydra cluster. Being the most massive/relaxed cluster within 50 Mpc, the Hydra is an irreplaceable/necessary laboratory to resolve the environmental effects on galaxies and quantify differences from the extensively studied, but less relaxed Virgo and less massive Fornax. Combining our ACA CO data with multi-wavelength data, we will study environmental effects on the cold ISM components and star formation activity in a resolved view, and most importantly, quantify cluster to cluster differences by comparing with Virgo and Fornax. | Galaxy groups and clusters | Cosmology | 2024-05-10T00:00:00.000 |
| 4849 | 2019.1.00562.S | 24 | Resolving the Disk Thickness of the perfect edge-on galaxy NGC 4302 | We propose to observe the 12CO(1-0) line toward the perfect edge-on (i~90 degree) galaxy NGC 4302 at a distance of 15 Mpc to measure the thickness of the gas layer. In order to resolve and measure the disk thickness accurately, we need a high angular resolution of 1" (70 pc) and a good S/N of at least 16, resulting in a noise level of 1.8 mJy over a spectral resolution of 5 km/s. According to previous works on the CO scale heights using edge-on galaxies (Yim et al. 2011, 2014, 2019), physical scales smaller than 100 pc are required to measure scale heights more accurately. Measurement of the CO scale heights along with the radial surface density profile will allow us to derive the average gas volume density that is more directly and physically relevant to the star formation rate. In addition, the volume density will enable us to derive the turbulent interstellar pressure which is suggested to regulate the star formation rate. Therefore, we will be able to better understand physics responsible for producing the observed exponent on the volumetric star formation law and the power-law correlation between SFR and the pressure by accessing the vertical distribution. | Spiral galaxies | Local Universe | 2021-04-22T15:56:49.000 |
| 4850 | 2018.1.00583.S | 131 | A Comparative Study of Feedback and Star Formation in BAL vs. non-BAL vs. Extremely-Red Quasars | Quasars have powerful outflows that could regulate high-redshift galaxy evolution, e.g., during early/active stages associated with dusty starbursts, strong broad absorption lines (BALs), or broad blueshifted [OIII] 5007 emission. We have a Cycle 5 ALMA Band 6 program to measure the host galaxies and feedback signatures around extremely red quasars (ERQs) that we discovered to have characteristically extreme [OIII] outflows. This program will map the molecular gas properties via the CO(7-6) and [CI](2-1) emission lines and star formation via the dust continua at 385 microns (rest) in a 0.63" beam. We now propose identical Band 6 observations of 24 blue/unobscured quasars in two subsamples, with and without BALs, carefully matched to the ERQs in luminosity and redshift z~2.4. This small request will yield the first comparative study of high-redshift quasar hosts and quasar-driven feedback in matched samples of BALs versus non-BALs and obscured versus unobscured quasars. It will determine if 1) BAL quasars have enhanced feedback/blowouts compared to non-BALs, 2) ERQs have enhanced feedback compared to blue/normal quasars, and 3) fast ionized [OIII] outflows play an important role. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2020-09-18T18:37:22.000 |
| 4851 | 2013.1.01175.S | 4 | The origin of the small scale CO outflow in HH 30 | The small collimation and acceleration scales (< 50 AU) in protostellar jets are currently best explained by magneto-centrifugal ejection from the inner AUs of the accretion disk. If confirmed, the MHD disk wind paradigm has strong impact on disk structure and evolution. However directly resolving the atomic jet launching regions ( <5 AU) is beyond current resolution capabilities in the optical/near-infrared. The recent detection of small scale molecular outflows in Class II sources opens new perspectives to test launching models. Indeed chemical modelling of MHD disk winds predict the flow to remain molecular for launching radii >1-3 AU. Alternatively these outflows could originate from thermal photo-evaporated flows. We propose to mapp in 12CO(2-1) at 0.25'' angular resolution the launching regions of the compact low-velocity molecular outflow around the prototypical Class II jet source HH 30. Cycle 2 capabilities offer the opportunity to directly resolve the launching region of the HH30 CO outflow, search for wiggling signatures and put firmer constraints on its specific angular momentum, allowing to discriminate between a purely thermal or magnetic origin for the wind. | Outflows, jets and ionized winds | ISM and star formation | 2017-02-07T00:00:00.000 |
| 4852 | 2022.1.01647.S | 9 | Imaging the inner disks of transition disks with large cavities | ALMA has revealed rich structures in planet-forming disks, including transition disks with large (>10s au) cleared-out cavities. Clearing by stellar or planetary companions can explain these cavities. Compact (few au) inner disks often surround the central stars. Gas crossing the cavity may feed the inner disk. Misalignment of the inner and outer disks hints at dynamic interactions, as do spiral arms and gas streamers. Infrared interferometry has characterized the rough geometry of the inner disks, but proper imaging is difficult at these wavelengths. ALMA has only marginally resolved inner disks, at no more than two beams across, yielding diameters of 0.06-0.1" (8-15 au). We propose to take advantage of the highest resolution ever offered by ALMA, 0.01", and image in 0.45 mm continuum the inner disks of GG Tau, HD142527 and AB Aur. This improves existing images by factors of 3-5 in resolution and reveals structure in the inner disks on 1.5 au scales. Well resolved images are essential to infer disk masses, study the alignment of the inner disk from VLTI to ALMA scales (0.1-10 au), and find substructures that betray dynamic processes and planet formation. | Disks around low-mass stars | Disks and planet formation | 2024-11-08T10:42:22.000 |
| 4853 | 2023.1.00052.S | 0 | The effect of the massive stellar feedback across the Carina Nebula Complex | Previous successfull ALMA campaigns have allowed the study of the location, mass distribution, and kinematics of the small-scale fragments within massive star-forming clumps in two regions with very different physical conditions, the Southern Pillars and the Northern Cloud. We propose to expand this sample towards 10 regions in the Carina Nebula Complex using the ACA 7m in Band 3. This represents, to our best knowledge, the first survey of clumps at high resolution conducted in this extreme region of massive star formation. Detailed comparison of the distribution of the dense gas and the location of young stellar objects will shed light on the dependence of the star-formation threshold on the level of turbulence and external pressure in these clouds with different level of impact of stellar feedback. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 3000-01-01T00:00:00.000 |
| 4854 | 2023.1.00444.S | 0 | A Chemical Survey of Externally-irradiated Protoplanetary Disks in Orion | Most planetary systems form in young stellar clusters, characterized by strong FUV/EUV fields from massive O- and B-stars. Hence, revealing the effects of external irradiation on disk chemical processes, temperature, and irradiation structure is essential to interpret the range of compositions observed in exoplanets and the solar system. We propose a comprehensive chemical survey of ten disks at 0.3" (120 au) resolution around low-mass stars in the Orion Nebula Cluster (ONC). Our sample spans three characteristic distance regimes from the O star Theta1 Ori C, the dominant UV source in the ONC. Our goals are to directly measure how the external radiation field impacts 1) the disk ionization structure, 2) the importance of disk photochemistry, and 3) the disk gas C/O ratio. This will be the first dedicated chemical survey of disks in close proximity an extreme UV radiation source. | Disks around low-mass stars | Disks and planet formation | 2025-09-13T14:14:57.000 |
| 4855 | 2015.1.01212.S | 8 | Molecular gas excitation in z=0.7 main sequence galaxies | Recent CO observations in normal main-sequence galaxies at high redshift have shown that their star formation efficiency is lower than in case of merger driven SMGs, more consistent with the star formation efficiency in local spiral galaxies. The picture that emerges from this studies is that SMGs form stars more rapidly because their gas clouds are more compressed so they churn more quickly through the available gas reservoir than the typical normal high-z disk galaxies. These differences in the physical conditions of the ISM are expected to affect the CO and CI line ratios. Our very first results from cycle 2 indeed show an unusual CI(2--1)/CO(7--6) line ratio, which indicates low gas densities in line with the expectation of diffuse gas in extended disks. A coherent picture of the gas excitation in main sequence systems, however, is missing so far. We here ask to continue our study of the gas excitation in main-sequence galaxies selected from the PHIBSS survey and to observe a small sample of z=0.7 galaxies. Our study aims to provide for the first time well characterized templates of the gas excitation in high redshift main-sequence galaxies. | Starburst galaxies, Galaxy structure & evolution | Active galaxies | 2017-01-07T15:58:13.000 |
| 4856 | 2018.1.00824.S | 104 | The diffuse molecular component in the nuclear bulge of the Milky Way | The old and well established view of the interstellar medium in the center of our Galaxy underwent an important change with our recent discovery of a low density gas component with an excitation temperature close to that of the cosmic background radiation, using the ALMA telescope. This new component may contains a significant fraction of the entire molecular gas mass. Given the successful results of our pilot study in Cycle 1, aimed to detect such diffuse gas in the bulge of the Galaxy, we propose to perform a complete characterization of the physical properties of this newly discovered component of the interstellar medium. In the previous cycle under the proposal 2017.1.01500.S only a minor fraction of the requested data has been observed. This time, in view of the exciting results, we aim to complete the observations to derive the physical properties of this gas. | Inter-Stellar Medium (ISM)/Molecular clouds | ISM and star formation | 2019-11-30T16:59:03.000 |
| 4857 | 2015.1.01426.S | 27 | Beaded Strings of Young Stellar Superclusters between Merging Elliptical Galaxies | We propose a Band 6 ALMA CO(3-2) observation to map a spectacular network of gravitationally unstable molecular filaments entwined amid the nuclei of two merging elliptical galaxies. The collapse of these 30 kpc-scale filaments fuels the birth of 19 young stellar superclusters or tidal dwarf galaxies, making this system one of the most unique known examples of so-called "beads on a string" star formation, a kpc-scale manifestation of the Jeans instability. Understanding both the origin and fate of this "string of pearls: now rests on ALMA, which is the only facility capable of mapping cold molecular gas in this morphologically short-lived structure. | Merging and interacting galaxies, Early-type galaxies | Galaxy evolution | 2017-07-26T18:26:34.000 |
| 4858 | 2022.1.01544.S | 1 | Chromospheric heating by shocks | State-of-the-art 3D MHD simulations of the Sun show that ALMA Band 3 is favourable for tracking shock waves all way from the lower to the upper chromosphere. In order to preserve the shock signatures, observations at as high angular resolution as possible are needed, in this case using array configuration C4 that is offered for solar observations at band 3. With such data towards the quiet Sun, the detected signatures can be correlated to the characteristic synthetic signatures from simulations and the transport of energy due to shock waves through the chromosphere per unit area could be estimated from both correlation to synthetic signatures of the MHD simulations and calculations of radiative losses in multifrequency inversions from IRIS co-observations. | The Sun | Sun | 2024-05-24T09:30:00.000 |
| 4859 | 2017.1.01370.S | 91 | OB-star binary systems in formation | We want to map two binary OB-star forming systems located at the hub/waist of large bipolar bubbles of two very luminous (10^6Lsun) HII regions namely G333.6-0.2 and NGC3576. A suite of adaptive optics assisted spectral and broadband imaging have uncovered distinct features that are common to both targets: 1) a pair of closely separated (<4000AU) embedded OB-stars, one of which is significantly more redder than the other. In NGC3576 the redder source also drives a collimated H2 flow, 2) a dusty edge-on disk-like feature (uncovered by 18um VLT/VISIR imaging) parts of it with intense BrG emission, and 3) loops and filamentary emission in the outflow cavities, that may be structures caused by radiation Rayleigh-Taylor instabilities. Our immediate goal is to map the gas velocities at comparable angular resolution and with km/s spectral resolution in radio-recombination and molecular lines, to identify rotation, inflow and outflow and determine whether these systems are really massive binary systems in formation. | High-mass star formation | ISM and star formation | 2019-11-26T21:54:02.000 |
| 4860 | 2013.1.00465.S | 4 | The first dusty envelopes and outflows around proto-BDs | The formation of brown dwarfs (BDs) is a hot field of research because there are no clear-cut examples of deeply embedded BDs (or proto-BDs), yielding a 'missing gap' between the stages prior to collapse and the stages where the object is almost formed and deprived of gas and dust. We have selected deeply embedded Spitzer sources in the Taurus region whose infrared magnitudes are consistent with a substellar nature and their colors are typical of Class 0/I protostars. In addition, these Spitzer sources are associated with sub-mm Herschel emisssion, and thermal radiojets like those found in low-mass protostars. ALMA is the only interferometer able to detect the 1-mm continuum and CO (2-1) emission of these faint objects, something crucial to unambiguously characterize their envelope and outflow properties, and compare them to the known stellar properties. This will provide definitive clues to disentangle the different formation scenarios of BDs. | Outflows, jets and ionized winds, Low-mass star formation | ISM and star formation | 2016-07-17T18:12:50.000 |
| 4861 | 2023.1.01517.S | 0 | Unveiling the origin of the mm continuum in radio-quiet AGN with ALMA polarimetric observations | Recent studies have shown that radio-quiet active galactic nuclei (AGN) ubiquitously show unresolved nuclear millimeter-continuum emission. This 100-200GHz emission is very tightly correlated with the X-ray emission, which makes it an excellent probe of the accretion power of AGN. The origin of this component is however still debated, and it could be created by: 1) self-absorbed synchrotron emission from the electrons that produce the X-ray radiation; 2) synchrotron emission from shocks due to the interaction between AGN outflows and the interstellar medium; 3) free-free emission from nuclear photoionized gas. One possible, still unexplored, way to discern among these mechanisms is through polarimetric observations in the mm regime, where these three different physical processes would produce different leves of polarization. We propose here to carry out, for the first time, 100 GHz polarimetric observations of three nearby radio-quiet AGN to understand the origin of the millimeter-continuum emission in AGN. | Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2025-02-13T19:21:12.000 |
| 4862 | 2011.0.00887.S | 0 | Monitoring fast variations of event-horizon scale gas in Sgr A* with frequency switching | Sgr A* in the Galactic Center is by now the best constrained supermassive black hole candidate. Its radio spectrum peaks at submm-waves and its size as measured with VLBI experiments shrinks with increasing frequency, exhibiting a clear size-frequency relation. The Millimeter-wave emission comes from less than four Schwarzschild radii and will allow imaging of the event horizon with mmVLBI in the future. The orbital time scale in Sgr A* is 24 minutes for a Schwarzschild black hole and the source frequently flares at radio, infrared, and X-ray wavelengths on timescales of hours. VLA monitoring has shown that there is a time lag of 20 minutes between flares at lambda 7mm and lambda 13mm, consistent with an outflow model. It is predicted that a lag-frequency relation should exist extending up to the mm-regime, but so far reliable multi-frequency mm-wave monitoring is not available. Here we want to use ALMA in a frequency switching mode to establish the variability properties of Sgr A* at different frequencies on orbital time scales of the black hole. Submm emission is ideal for this, since it is optically thick emission, probing actual bulk plasma motions and densities. X-ray and IR flares are in contrast completely optically thin and hence much more sensitive to particle heating. Hence Alma monitoring may become a powerful tool for understanding Sgr A* and black holes in general. The observation should, for example, establish the lag-frequency relation, which together with the existing size-frequency relation would provide a quantitative tool to constrain flow speed and acceleration of gas within a few Schwarzschild radii of the event horizon. Finally, the integrated data set will provide the best-ever multi-frequency map of the gas streamers (Sgr A West) in the Galactic Center. | Black holes | Stars and stellar evolution | 2013-10-01T14:20:31.000 |
| 4863 | 2024.1.00467.S | 0 | A [CII] survey of a complete sample of dusty star-forming galaxies at z=3-5 | The [CII] emission line is the brightest in far-infared and serves as a key coolant of the ISM. Its study offers insights into the cool gas properties of galaxies from the local universe to the epoch of reionization. Recently, an ALMA spectroscopic survey successfully determined redshifts for a flux-limited and complete sample of 54 bright, unlensed dusty star-forming galaxies at z=2-5 that have an average infrared luminosity of ~10^13 solar luminosity. We here propose a [CII] survey on 27 of this sample at z=3-5, where the [CII] line is shifted to wavelengths less affected by atmospheric absorption. The proposed observations will allow construction of the [CII] luminosity functions within this redshift range. Combined with existing CO/[CI] measurements on this sample, we will study ISM conditions of these luminous sources, and provide constraints on the high-mass and more active end of the [CII]-gas mass and [CII]-SFR correlations. We will also be able to estimate sizes in a few large sources and conduct meaningful searches of immediate companions to further study their halo environments. | Sub-mm Galaxies (SMG), Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 4864 | 2022.1.01173.S | 80 | Identifying targets for cross-checking blackhole mass measurements | Supermassive black holes (SMBHs) are key to understanding galaxy evolution, but the SMBH mass-central velocity dispersion relation is based on a relatively small number of measurements and a handful of methods. It is straightforward to measure the mass of SMBHs in the ALMA era, by probing the near-Keplerian rotation of CO disks around them. This method has been demonstrated in recent years. In order to further compare the SMBH mass measured by CO kinematics with other methods, we propose this 7-m ACA proposal to find suitable targets for subsequent higher resolution follow-up. We select targets with regular dust disks (from HST imaging) and robust masses from other methods. We request low spatial resolution CO(2-1) imaging of 9 galaxies. We aim to quantify their molecular gas content, thus identifying the best targets for SMBH measurements at higher resolution, and 2) as a byproduct, study the abundance and kinematics of molecular gas and look for suitable targets for follow-up resolved observations of giant molecular clouds. | Galactic centres/nuclei | Active galaxies | 2024-03-08T10:31:59.000 |
| 4865 | 2015.1.01593.S | 80 | Multi CO line imaging of the nearby galaxy M83: Variation of cloud properties across the g|observe gas clouds dens alactic structures | We propose 13CO (1-0) and 12CO (3-2) mapping observation of the nearby galaxy M83 with 1.8"" (~40 pc) resolution over ~5.4 kpc^2 area, which includes eastern half of the bar, the nucleus, and part of the eastern spiral arm. Target field of the observation is aligned with ongoing cycle 2 project, which perform wide-field imaging of dense gas tracers, including HCO+ and HCN. By comparing with the already available total-power-recovered 12CO (1-0) map and upcoming HCO+/HCN data, we will constrain physical properties of GMCs via non-LTE LVG analysis to see how cloud properties variate across the galactic structures, and to see whether GMC properties seen at ~40pc resolution is related to star formation. Molecular bar in M83 is CO bright. Along the bar, there exists continuous molecular ridge with surface mass density (SMD) over 800 Msun pc-2. At the nucleus it rises over 4000 Msun pc-2, and even in inter-arm, there exists plenty of molecular gas with SMD as high as that of typical GMCs. There is a concern that non-circular motion induced by the bar has increased velocity gradient and made CO emission overluminous. We will also test this by constraining conversion factor. | Spiral galaxies, Giant Molecular Clouds (GMC) properties | Local Universe | 2017-11-24T21:29:36.000 |
| 4866 | 2023.1.00556.S | 0 | Resolving the growth of massive galaxies in cosmic web filaments | The cosmic web filaments are thought to fuel the growth of galaxies and SMBHs under the current cosmological framework. Therefore growing galaxies exactly within a remarkable gas filament provides a unique laboratory. In this regard, invaluable targets have been discovered at a z=3.1 proto-cluster core. A number of bright dusty star-forming galaxies (DSFGs) are found to reside in Mpc-scale Lyman-alpha filaments, which is suggestive of fueling by the cosmic web. ADF22.A1, which is one of the most luminous DSFG in the protocluster, were recently resolved in [CII] (0.2") and dust (0.034"). The observations demonstrated that such high-resolution mapping of the ISMs are powerful tool to understand massive galaxy assembly, unveiling starburst cores driven by the bar-potential in a giant barred spiral galaxy. Following the successful pilot survey, here we propose [CII] 158um imaging of the other 5 brightest DSFGs in the protocluster. With the flux limited sample, together with the pilot, in our hands, we will (i) unveil what drive the intense starburst activity, revealing bars, spirals, and mergers and (ii) uncover proto-bulge formation and its connection to NIR-dark natures. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2025-09-04T19:51:31.000 |
| 4867 | 2012.1.00187.S | 1 | X-ray irradiated dense molecular medium in the active nucleus of NGC 1097: 10 pc scale molecular view around a type-1 AGN | We propose to study the physical, chemical, and dynamical properties of densest ($n_{\rm H_2} > 10^6$ cm$^{-3}$) molecular gas traced by HCN(4-3) and HCO$^+$(4-3) at the vicinity of the type-1 Seyfert nucleus of NGC 1097 at $0.''16$ or 11 pc resolution. Moderately dense gas traced by CO(3-2), and 860 $\mu$m continnum will be simultaneously mapped, too, and some meaningful upper limits of molecular lines such as CS(7-6) and vibrationally excited HCN will be obtained in a single setup of ALMA Band 7. We have already obtained $1''.5\times1''.2$ resolution images of HCN(4-3) and HCO$^+$(4-3) in the center of NGC 1097 using the almost same frequency setup of ALMA Band 7 (2011.0.00108.S, PI=K.Kohno). This cycle 0 observation uncovered a bright and unresolved ($< 1''.2 \times 0''.76$ or $< 84 \times 53$ pc) condensation of densest molecular gas traced by HCN(4-3) and HCO+$^+$(4-3) at the nucleus, and the measured flux and source size validate the feasibility of our proposed study aiming $\times$10 zoom into the active nucleus. We also find a striking enhancement of HCN(4-3)/CS(7-6) flux ratio ($>$ 10) at the nuclear dense gas condensation, and the ratio is significantly higher compared with those in starburst galaxies/star-forming regions (e.g., $\sim$3.5 in NGC 253 and $\sim$1.7 in Ori-KL). This will add further evidence for the presence of dense gas strongly affected by AGN in NGC 1097. The immediate objectives are then summarized as follows. (1) To obtain the first 10 pc scale view of the densest molecular gas at the vicinity of the type-1, (i.e., unobscured) active nucleus. Can we resolve the outer envelope of the putative obscuring material? (2) To study the kinematics of dense molecular gas around the active nucleus at $\sim$10 pc scale. Can we see any kinematical signature of radial transport of molecular material at $\sim$10 pc scale? (3) To measure the variation of physical/chemical properties of dense molecular gas as a function of the distance from the active nucleus. Can we find any radial variations of molecular line ratios caused by the difference of the impact from the AGN on the surrounding gas at $\sim$10 pc scale? | Active Galactic Nuclei (AGN)/Quasars (QSO), Galaxy chemistry | Active galaxies | 2016-11-24T21:19:17.000 |
| 4868 | 2021.1.00531.S | 16 | Nature of the UltraLuminous X-ray source (ULX) bubbles powered by fast outflows | Ultra-Luminous X-ray Sources (ULXs) are incredibly bright (>10^39 erg/s) and compact X-ray sources. They are a prime candidate for the Intermediate Mass Black Hole (IMBH) with sub-Eddington accretion but can also be a stellar-mass BH with super-Eddington accretion. To judge which types of the BH is present in ULX is one of the biggest questions in modern astronomy. Some ULXs are accompanied by extended radio emission (ULX bubble), heated by shocks generated by small-scale outflows in X-ray. Such bubbles should sweep up the ISM to form molecular gas regions. Spatially-resolved observations with ALMA allow us to determine their kinetic power accurately. If the accretion is super-Eddington, the outflow should be strong and the kinetic power of the swept-up ISM is expected to be significant, and vice versa. In this proposal, we aim to constrain the accretion system of ULXs by measuring the kinetic power of the CO emission lines associated with the ULX bubbles. We select two ULXs, NGC 5408 X-1 and NGC 1313 X-2. This proposal is also the first molecular line search toward the ULX bubbles. | Black holes | Stars and stellar evolution | 2022-11-26T17:51:38.000 |
| 4869 | 2015.1.01559.S | 25 | From Dust till Dark: Dissecting SMM J0658 the brightest strongly lensed galaxy behind the Bullet Cluster | We propose to observe SMM J0658 ($z=2.7793\pm1\times10^{-4}$) the brightest lensed galaxy behind the Bullet Cluster. The exceptional lensing circumstances (that cause this source to split into three distinct images with a total magnification of about 100), together with the superb angular resolution and sensitivity of ALMA makes it possible to probe the conditions of the neutral ISM in a LIRG with a mass similar to that of the Milky Way. For this aim, we have improved over the Bullet Cluster lens modeling to account for differential magnification in the combined analysis of the proposed observations along with our published CO(10) observations in the modeling of the CO spectral line energy distribution (SLED). SMM J0658 is the lowest mass galaxy at $z\sim2.5$ where such detailed analysis is allowed. Therefore, the proposed observations are key to understand star formation in the most common galaxy population at $z>1$. | Sub-mm Galaxies (SMG), Gravitational lenses | Galaxy evolution | 2017-10-28T19:41:31.000 |
| 4870 | 2019.1.01482.T | 16 | Revealing the Structure and Magnetization of GRB Jets with ALMA Polarization Observations | Polarization measurements of the afterglows of long-duration gamma-ray bursts (GRBs) probe the structure and magnetization of their relativistic jets, revealing the nature of their elusive central engine. While reverse shock (RS) polarization probes magnetic field structure in the jet, polarized forward shock (FS) emission is sensitive to the jet angular structure and viewing geometry. The ideal window to search for these polarization signatures is in ALMA Band 3, where both components are observable longer than at higher frequencies, while still being unaffected by interstellar scintillation and depolarization from synchrotron self-absorption. Our pioneering ALMA Cycle 6 full Stokes observations of GRB 190114C uncovered a polarized RS at 97 GHz (the first detection of radio/mm polarization in a GRB), allowing us to infer the angular coherence scale and magnetic field geometry in the jet. We now propose to triple our sample with linear polarimetry of up to two new GRB afterglows in Cycle 7 to determine whether the low level of polarization (~1%) we measured in 190114C is common, aiming to constrain the central engine and jet acceleration mechanisms in these relativistic transients. | Transients | Stars and stellar evolution | 2022-12-23T20:51:53.000 |
| 4871 | 2011.0.00645.S | 0 | Winds of change? - probing the nuclear activity and outflow of the FIR-excess galaxy NGC1377 v1.5 | ALMA offers a unique opportunity to probe the nature of FIR-excess galaxies where the IR emission is powered by dust-embedded starbursts and/or AGN activity. The molecular outflow and dusty core of the extreme FIR-excess, synchrotron deficient galaxy NGC1377 presents an opportunity to study this important phenomenon. We propose extended array CO 1-0 observations to image the molecular outflow to determine its age and address the nature of the dust enshrouded nuclear activity: an extremely young (1~Myr) starburst or a super-Eddington accreting black hole. We furthermore propose CO 6-5 and 690 micron continuum observations also in extended to study the buried central source on scales of 20 pc. We expect intense, 50-80 K emission from the very nuclear region probing the dynamics of the inner disk, the enclosed mass and the gas heating/energy budget. The continuum will constrain the IR surface luminosity and dust mass. This proposed study will allow us to uniquely probe the very earliest phases of nuclear activity - the onset of black hole accretion or the pre-synchrotron beginnings of a starburst. | Galactic centres/nuclei, Active Galactic Nuclei (AGN)/Quasars (QSO) | Active galaxies | 2013-10-17T09:12:51.000 |
| 4872 | 2015.1.00761.S | 31 | Disk Masses and Dust Grain Growth in Class I Protostars in Ophiuchus | Recent studies suggest that protoplanetary disks around 1-5 Myr old pre-main sequence stars contain insufficient mass to form giant planets. This may be because by this stage much of the material in the disk has already grown into larger bodies, hiding the material from sight. To test this hypothesis, we propose to observe a diverse sample of protostars in Ophiuchus younger than 1 Myr, whose disks are more likely to represent the initial mass budget of protoplanetary disks for forming planets. We will measure the mass of the disks around these protostars, constrain the maximum dust grain sizes in the disks, determine the geometry of the circumstellar material of these systems, and trace Keplerian rotation in the disks to measure the masses of the central protostars. By comparing the disk mass distribution and maximum dust grain sizes we derive for our sample with the existing 1-5 Myr old disk sample we will constrain the initial mass budget for forming planets in protoplanetary disks. We submitted a complementary proposal to repeat the experiment in Taurus but kept the proposals separate as they explore different star forming regions and are each self contained. | Low-mass star formation | ISM and star formation | 2017-01-12T21:38:26.000 |
| 4873 | 2023.1.01585.S | 75 | Testing the mass complexity of massive elliptical galaxies with precision gravitational lens modelling and ALMA | Strong gravitational lensing is a well-established tool to probe the mass structure and dark matter distribution in galaxies. However, fundamental to these lines of research is the parameterisation of the large-scale mass distribution of the lensing galaxy, which is usually assumed to be an ellipsoidal power-law density profile with external shear. Several recent works highlighted the limitations of a power-law model and the impact this can have on the astrophysical applications of gravitational lensing, particularly in regard to testing dark matter models. Observations of lensed starburst galaxies with ALMA can provide the most detailed test of complexity, given higher angular resolution than current optical telescopes. Here, we propose to observe 12 lenses at 30 mas resolution. We will measure the angular complexity using both parameteric and non-parametric modelling, compare this to predictions of hydrodynamical simulations and characterise the systematic bias in lensing studies. Furthermore, this sample will be key to set up 10 mas observations in future cycles, which will provide fundamental tests of the nature of dark matter. | Gravitational lenses | Cosmology | 3000-01-01T00:00:00.000 |
| 4874 | 2016.1.01552.S | 124 | Characterizing diffusive processes in the B335 protostar | The ionization fraction in protostellar environments is a key ingredient responsible for the efficiency of most diffusive processes allowing to diffuse the magnetic field in protostellar enevlopes, therefore modifying strongly the efficiency of magnetic braking during the main accretion phase. Recent observational and theoretical results highlight the role of magnetic braking in other long-standing problems in astronomy such as the angular momentum problem, and the formation of stellar binaries and disks. Here, we propose to simultaneously and independently characterize the magnetic topology, magnetic intensity, and diffusive processes in a young protostar, B335, using observations of molecular ions to be combined with our already obtained polarization data. We will characterize finely the coupling of the field to the circumstellar gas, and describe the efficiency of magnetic braking to drive angular momentum transport, regulate the accretion rate, and affect disk formation in this young accreting protostar. | Low-mass star formation, Astrochemistry | ISM and star formation | 2018-02-14T18:46:58.000 |
| 4875 | 2019.1.00226.S | 55 | A kpc-scale view to the dust and gas content of typical star forming ALPINE galaxies at z~4.6 | This proposal is designed to get a detailed view (up to kpc-scales) to the gas and dust content of three carefully selected normal (>0.6L*) galaxies at z~4.6. The galaxies are extracted from the ALPINE survey and they have been already detected at high signal to noise in [CII] and ~160um continuum. The galaxies are massive although follow the so-called "main sequence" for star forming galaxies at z~4.6. These sensitive and high resolution observations will facilitate an initial exploration of the interplay between the star-formation activity and the dynamical state on those galaxies which are part of the bulk of the galaxy population. Our main goals are: (1) to reveal the radial profiles of the gas-to-dust ratio and put them in context with galactic evolution models, (2) the exploration for the validity of the Schmidt-Kennicutt law in these "normal" z~4.6 galaxies, (3) use high-resolution data to prove their dynamical disk-like or merger nature, (4) explore the role that dark matter halos have in building the baryonic matter in the early Universe, and (5) identify massive clumps of star-formation and their level of stability on rotating disks. | Lyman Break Galaxies (LBG), Galaxy structure & evolution | Galaxy evolution | 3000-01-01T00:00:00.000 |
| 4876 | 2016.1.01071.S | 136 | Investigating the missing piece of the prebiotic chemistry puzzle: Interstellar Phosphorus | Phosphorus is a key ingredient for the development of life. Despite its critical role in basic astrobiology very little is known about the chemistry of phosphorus in the interstellar medium due to the lack of observations of P-bearing molecules. Recently, our group has reported new single-dish detections of PN towards a sample of massive cores at diferent evolutionary stages of massive star formation, and for the fist time the detection of PO towards star-forming regions. However, our single-dish data does not allow us to properly derive the molecular abundances because the size of the emitting region is completely unknown, and consequently we cannot compare with theoretical model predictions. Therefore, we aim to perform for the first time high angular observations of PN and PO towards two massive protoclusters containing up to 5 cores at different evolutionary stages. The comparison of the observations with our already developed chemical models will provide a significant progress in our understanding of the chemistry of phosphorus in star-forming regions and put solid basis to the further development of a chemical network for more complex P-bearing species. | High-mass star formation, Astrochemistry | ISM and star formation | 2018-07-21T17:54:37.000 |
| 4877 | 2021.1.01515.V | 0 | Dynamics of the Centaurus A jet base on a light-day scale | Centaurus A is the closest radio-loud galaxy to our Milky Way. While the galaxy is overall well studied, the active central region has never been resolved at high angular resolution. Such studies are now becoming possible with the ALMA VLBI mode. The first observation in Cycle 4 resulted in a first resolved image of the jet base with a puzzling, strongly edge-brightened structure and seemingly evacuated jet spine (priv. communication). We propose 2 days of follow-up observations with phased ALMA joining the Event Horizon Telescope VLBI array. With the Band 6 resolution corresponding to a linear scale of 0.5 light-days, two observations separated by several days will allow to investigate stability of the image morphology and the inner jet dynamics. Additionally, technical upgrades to the EHT array will enable imaging weak linear polarization structure of the source and following its dynamics between the observing days. These observations, particularly together with simultaneous multiwavelength data, will greatly improve our understanding of the system, as well as our general comprehension of the relation between supermassive black holes, magnetic fields, and jets. | Active Galactic Nuclei (AGN)/Quasars (QSO), Outflows, jets, feedback | Active galaxies | 2025-07-11T09:26:46.000 |
| 4878 | 2017.1.01010.S | 35 | Spatially Resolved Gas-Star Formation-Dynamics in z~2.5 SMGs | Decades after discovery of the first sub-millimeter galaxies (SMGs), the fundamental physics involved in converting their gas to stars still remains under debate. With rare exceptions, measurements of the star formation law in high-z galaxies are mostly based on unresolved SFR and gas mass estimates. Here we propose to obtain spatially resolved CO (3-2) maps (with 0.3' resolution) for two z=2.5 SMGs that have complementary high resolution IFU spectra. With CO (3-2) maps matching the resolution of Halpha maps, we will be able to determine the fundamental relation between molecular gas density and SFR density at kpc scale. The combined dataset is ideal for exploring the complex interplay between star formation, gas density, and galaxy internal dynamics. This includes the role of small scale dynamics in driving different star formation efficiency, and conversely, the role of gas fraction and star formation (feedback) in driving the enhanced intrinsic velocity dispersion. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2019-02-26T15:59:25.000 |
| 4879 | 2013.1.00459.S | 0 | Mapping CI in the beta Pictoris debris disk | The dusty debris disk around the ~20 Myr old main-sequence A-star beta Pictoris is known to contain gas. Evidence points towards a secondary origin of the gas as opposed to being a direct remnant from the initial protoplanetary phase. The dominant gas production mechanism is not identified so far, but believed to be connected to the dust. The reason for the extreme overabundance of C and O compared to metallic elements (e.g. Na, Fe) is also unknown. We propose to use ALMA to map the C I 492 GHz emission from the carbon-rich gas disk around beta Pic. By spatially and spectrally resolving the emission, ALMA will in particular address the following questions: 1) What process produces the circumstellar gas? 2) What is the mechanism behind the extreme overabundance of C in the gas disk? 3) What is the C/O ratio of the gas? Of key importance in answering these questions will be a comparison to recent ALMA observations of CO(3-2) in the disk. In addition, simultaneous observations of the dust continuum combined with archival data will map dust properties such as the grain size distribution in the disk. | Debris disks | Disks and planet formation | 2018-10-25T20:07:38.000 |
| 4880 | 2017.1.01659.S | 4 | Resolved distribution and dynamics of molecular gas of a distant spiral galaxy | We propose to detect the CO (2-1) emission line in a moderate redshift galaxy (z=0.56) to infer the gas distribution and velocity field at a resolution of 0.4 arcsec (2.5 kpc). The immediate objective of this pilot study is to determine the shape and amplitude of the rotation curve out to two disk scalelengths. This would be the first time that a gaseous rotation curve is obtained for a supposedly distant, unperturbed disk. A second objective is then to compare the CO kinematics with the optical [OII] doublet kinematics observed in 2008 by means of VLT/GIRAFFE observations of the same galaxy. The ALMA observations will be 2.5 times more resolved than the GIRAFFE data and allow us to assess whether the velocity plateau used for the Tully-Fisher relation from GIRAFFE is correct. Resolved ALMA observations of distant galaxies would open a new window for the dynamics of rotating disks. | Spiral galaxies | Local Universe | 2019-12-07T09:37:21.000 |
| 4881 | 2017.1.01109.S | 232 | How universal are surprisingly significant molecular gas reservoirs in massive post-starburst galaxies at z~0.6? | Below z~1, massive galaxies are primarily ellipticals with quiescent stellar populations. Despite many investigations, the question of why these galaxies stopped forming stars remains subject to much debate. We have launched a multi-wavelength campaign to study massive, post-starburst galaxies selected from SDSS spectroscopic survey at z~0.6, where lookback times are significant and relatively short observations (~2 hours) can reveal even extremely low gas fractions. Intriguingly, our ALMA Cycle 4 observations of CO(2-1) in two galaxies revealed significant molecular gas reservoirs (log(M/Msun)~10) despite their low ongoing star-formation rates.These results suggest that quenching can shut down star formation in molecular gas without removing it from the galaxy; however, definitive conclusions require a statistical sample. We propose to follow this successful strategy for a complete sample of 11 additional massive, bright, and quiescent post-starburst galaxies. By combining the molecular gas content and kinematic properties of these 13 post-starburst galaxies with hydrodynamic galaxy simulations, this survey will provide new insight into why galaxies enter their quiescent phase. | Galaxy structure & evolution | Galaxy evolution | 2019-04-03T21:19:14.000 |
| 4882 | 2012.1.01099.S | 1 | The Crab nebula at 100GHz: filling in the gap | We propose to carry out the first high-resolution continuum imaging of the central region of the Crab nebula at mm wavelengths. These observations will complement our ongoing campaign to study the Crab PWN with Chandra, HST, and EVLA. Our science goal is to understand the physical processes responsible for the formation of the PWN features, uncover the spectral energy distribution (SED) of the injected particles and its evolution across the nebula. Additionally, we will shed light on the origin of the flares observed in the high-energy (gamma-rays) PWN flux. The proposed observations will provide the first image of the Crab nebula in the 100 GHz window with an angular resolution of about 1 arcsec. The Crab is an iconic object, and the high-resolution, high-quality image at millimeter wavelengths will certainly have a long-lasting scientific impact and legacy value. To carry out this project we request the use of ALMA 12-m array in the C32-4 configuration (2.2 hrs) and the compact 7-m array (6.6 hrs). | Pulsars and neutron stars | Stars and stellar evolution | 2015-10-07T17:26:44.000 |
| 4883 | 2016.1.00386.S | 207 | Molecular Clouds and Star Formation: Across M83 | We propose an arcsecond-resolution imaging of molecular gas in the central 10 kpc of M83, a third of which has been taken in Cycle 3. We will study molecular gas and cloud properties, star formation, their interrelation as well as relation to gas dynamics. M83 is the nearest face-on grand-design spiral galaxy with a stellar bar. Our mapping area contains two grand-design spiral arms, entire bar, and most of star forming regions in the galaxy. We will resolve individual GMCs at 20 pc resolution and achieve 10-sigma mass sensitivity of 1e4 Msun for beam-size clouds. Statistical properties of the GMCs will be anlyzed as a function of gas dynamical environment (e.g., circumnuclear, on/off bar, bar-end, on-/inter-arm, and outer disk). We will also quantify using HST data the association of GMCs to young star clusters and HII regions. Our central question is : How do galactic structures such as the bar and spiral arms affect the properties of GMCs and subsequent star formation? Our unprecedentedly detailed wide-area observations will allow a significant progress toward its answer. The data will also serve as a base for multi-wavelength studies of M83 by the community. | Starbursts, star formation, Giant Molecular Clouds (GMC) properties | Active galaxies | 2019-03-26T00:00:00.000 |
| 4884 | 2024.1.01191.S | 0 | Constraining the gas content and excitation mechanism in the Spiderweb protocluster at z=2.2 | According to the hierarchical merging scenario, mass assembly strictly links to the build-up of large-scale structures. Therefore, constraining the gas content and excitation mechanism of intensely star forming galaxies in galaxy clusters in formation is essential for our understanding of star-formation at high redshift. Recent ATCA observations reported 46 CO(1-0) emitters in the Spiderweb protocluster at z~2.2. Our objective is to constrain the molecular content using CI lines, considering the diverse physical conditions in this dense environment. To achieve this, we propose the ALMA 12m array to observe CO(4-3), CO(7-6), [CI](1-0) and [CI](2-1) of 10 cluster members with both robust ATCA CO(1-0) and ALMA CO(3-2) detections. With the proposed observations, we aim the following: i) derive securely the molecular mass based on two [CI] lines; ii) constrain the gas excitation condition; iii) constrain the infrared luminosity; iv) explore the environmental effect by comparing to the field galaxies at similar redshift. These observations will enable us to constrain the gas content and excitation mode, thus understanding the formation of protoclusters. | Sub-mm Galaxies (SMG) | Galaxy evolution | 2025-10-24T18:53:41.000 |
| 4885 | 2022.A.00009.T | 44 | Radio polarimetry for extremly energetic GRB221009A | We propose conducting two epochs of linear polarimetry with Band3 and Band4 using the 12-m array and photometry with Band3/4/5 using the standalone mode of ACA for the brigh GRB221009A afterglows to constrain the fraction of non-energized electrons along with the spectrum peak. The energetic GRB221009A (2-3 orders larger than the typical one) was just discovered on 9 Oct. 2022. Intensive multi-wavelength observations have been ongoing. One notable feature is the association of very high-energy photons up to 18 TeV. These prompt emission features make GRB221009A one of the historical events. The first X-ray polarimetry for the X-ray afterglow by NASAs IXPE satellite. Radio polarimetry using ALMA would enhance understanding of this energetic GRB. | Gamma Ray Bursts (GRB) | Cosmology | 2023-04-26T11:29:12.000 |
| 4886 | 2017.1.00735.S | 0 | Characterizing the Morphology, Kinematics, and Excitation in the Nuclear Region of Arp 220 | Our ALMA observations of CO J=6-5, 3-2 and 13CO 4-3 in a late-stage galaxy merger, Arp 220, provide key insights into an important phase of galaxy evolution. Deep CO absorption (going below the continuum baseline) is detected at the centers of the merging nuclei. Evidence for a molecular outflow and a signature of an infall is found associated with the nuclear region, which also shows extreme column density and large dust optical depths. Multiple CO transitions are needed to characterize the deep absorption features seen in the two nuclei, to estimate the mass and model the excitation of the infall surrounding the nuclear disks, and to measure the spatial variation in excitation and kinematics by comparing the cold (low-J) and warm (high-J) gas maps. 12CO 4-3, 8-7, and 13CO 6-5 were part of our accepted Cy3 program but could not be observed and thus we are re-proposing them in Cy5. 13CO 6-5 will supplement 13CO 4-3 to unambiguously discriminate between absorption and outflow models and place limits on the 12C/13C isotopic ratio. Arp 220 is bright and has highly excited molecular gas and therefore makes an excellent target for utilization of ALMA at high frequencies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Merging and interacting galaxies | Active galaxies | 2019-11-22T16:10:07.000 |
| 4887 | 2019.1.01072.S | 5 | Mira. The first AGB star in a triple system ? | Binary/multiple stellar systems, which are as abundant as single stars, are very interesting cosmic laboratories as they are related to many astrophysical phenomena. In the case of AGB (and post-AGB) stars, they are the most likely explanation for the shaping of non spherical PNe, a long standing problem. While many binaries are known in PNe, there are few examples in the previous AGB phase. Hydro models are available, but known orbital parameters for AGB binares are almost nonexistent. We propose to observe the closest bona fide binary with an AGB primary, Mira. The system is well studied and there are many indications that the system is in fact triple, and that the yet unseen component, Mira C, is strongly interacting with the AGB primary Mira A, affecting its pulsation and its mass loss. We claim that this third component is tentatively detected in public data from project 2017.1.00393.S, and we propose to perform a deeper integration in ALMA band 6, with 23 mas HPBW, in order to confirm this. At the same time we will also improve the values for the Mira AB orbit, obtain its mass ratio, and take a close look at how this triple system is shaping the AGB wind from Mira A. | Asymptotic Giant Branch (AGB) stars | Stars and stellar evolution | 2022-11-09T01:25:16.000 |
| 4888 | 2013.1.01222.S | 0 | A Survey of Extragalactic Megamasers at 321 GHz | We propose to observe the water maser transition at 321 GHz in 5 galaxies in which large abundances of water have been detected. Since the discovery of water maser emission three decades ago, the only concerted extragalactic surveys have been carried out at 22 GHz. Extending the study to other water maser transitions is crucial to understanding the excitation conditions of the water molecule and to provide constraints on the models of pumping mechanisms. Only through constructing a comprehensive model of these physical conditions can we hope to obtain an accurate picture of the central parsecs of active galactic nuclei and the regions of most intense star formation in starburst galaxies. | Active Galactic Nuclei (AGN)/Quasars (QSO), Surveys of galaxies | Active galaxies | 2017-01-25T22:32:32.000 |
| 4889 | 2012.1.00422.S | 1 | Determination of the TW Hya Disk Mass | The main constituent of protoplanetary disks, gaseous molecular hydrogen, does not emit from the disk mass reservoir and the most common technique to measure the disk gas mass in extra-solar systems is via dust thermal emission. However, this method generally assumes that we know how the grain properties and the gas-to-dust mass ratio evolve from their interstellar medium values which is highly model dependent and poorly constrained by actual observations. Thus even in TW Hya, the closest template object, there is a large discrepancy in the total disk mass. We propose here to use ALMA, combined with unique Herschel data, to determine the total disk gas mass in the TW Hya disk. Recently, using Herschel, we detected the ground-state transition of HD, an excellent probe of H2 gas, and therefore mass. This transition is however sensitive to the disk gas temperature structure deeper inside the disk than probed by CO. We request observations of 13CO (with C18O) J = 6 - 5 and J = 3 - 2 at an angular resolution of 0.5", thereby resolving the region where 25 - 60% of the HD emission is predicted to arise. The ALMA and Herschel data will be used in tandem to to empirically determine the gas excitation deep in the TW Hya disk and its gas mass.This is a fundamental estimate of the primary quantity that controls planet formation. | Solar system - Comets | Solar system | 2015-08-19T18:32:57.000 |
| 4890 | 2016.1.00279.S | 260 | Towards a complete sample of z~7 dusty starbursts | Using data coming from the ongoing S2COSMOS survey (a deep SCUBA2 map of the COSMOS field at 850um) we have uncovered a population of 28 Extremely Red Starbursts (ERS) with very red SCUBA2-to-SPIRE colors that suggest redshifts z > 6. This allows us to study the very-high-redshift tail of the SMG population with a statistically useful sample for the first time (only one dusty starburst has been confirmed to be at z > 6 up to date, HFLS3 at z = 6.34). We propose to carry out continuum observations in B8 and B6 to confirm the red FIR/submm colors of our ERS, pinpoint the positions of the sources, obtain FIR photometric redshifts, derive the number density of z>6 dusty starbursts and feed galaxy formation and evolution models, which generally predict that this population must have tremendously decreased at z > 4. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2018-04-29T04:38:13.000 |
| 4891 | 2019.1.00486.S | 200 | Completing the SPT+ALMA Redshift Survey | Recent ground and space-based multi-wavelength (sub)millimeter surveys have discovered a large number of strongly lensed, ultra-bright sub-mm galaxies (DSFGs). From these surveys, particularly the 2500 sq. degree South Pole Telescope (SPT) survey, we have constructed a catalog of 81 high-redshift DSFGs. Previous ALMA proposals have enabled us to determine the spectroscopic redshifts for >91% of these sources using ALMA's 3mm line scans. In this proposal, we present the final 7 sources for which we either detect a single line feature or no features. The sources that do not have any 3mm detections are, however, detected in continuum and likely to be either at high redshift or be potential protoclusters. We therefore request time to perform deeper spectroscopic line scans. In other sources, we can narrow the line identification to two plausible CO transitions and request time to break the degeneracy between redshift solutions. Obtaining robust redshifts for the complete catalog of SPT sources will enable further study into star formation rate for this highly elusive population of galaxies, and further our understanding of galaxy evolution. | Starburst galaxies, Sub-mm Galaxies (SMG) | Active galaxies | 2021-03-30T19:24:20.000 |
| 4892 | 2022.1.01080.S | 20 | Dynamics in Venus' Sub-cloud Atmosphere | An outstanding uncertainty in the maintenance of Venus' atmospheric super-rotation is the dominant mechanism of angular momentum transport from the lower atmosphere to the upper atmosphere. The atmospheric thermal lapse rate governs which of these processes can occur, with an adiabatic rate suggesting thermally direct transport and a sub-adiabatic rate suggesting primarily wave-based transport. If wave-based transport is dominant, signatures of horizontal wave activity should also be present in the sub-cloud atmosphere. We propose observations of Venus with ALMA and the VLA achieving vertical resolution of 10 m from 0-40 kilometers and with sufficient sensitivity to resolve weak thermal wave signatures in the sub-cloud atmosphere. | Solar system - Planetary atmospheres | Solar system | 2024-05-22T16:06:03.000 |